Flarenet modelling

Reference ManualAspen Flare System Analyzer Version: V7.3 March 2011 Copyright (c) 1981-2011 by Aspen Technology, Inc. All rights reserved. Aspen Flare System Analyzer, Aspen Flarenet, Aspen Plus, Aspen HYSYS, Aspen Plus Dynamics, and the aspen leaf logo are trademarks or registered trademarks of Aspen Technology, Inc., Burlington, MA. All other brand and product names are trademarks or registered trademarks of their respective companies. This document is intended as a guide to using AspenTech's software. This documentation contains AspenTech proprietary and confidential information and may not be disclosed, used, or copied without the prior consent of AspenTech or as set forth in the applicable license agreement. Users are solely responsible for the proper use of the software and the application of the results obtained. Although AspenTech has tested the software and reviewed the documentation, the sole warranty for the software may be found in the applicable license agreement between AspenTech and the user. ASPENTECH MAKES NO WARRANTY OR REPRESENTATION, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS DOCUMENTATION, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. Aspen Technology, Inc. 200 Wheeler Road Burlington, MA 01803-5501 USA Phone: (781) 221-6400 Toll free: (888) 996-7001 Website http://www.aspentech.com Contents i Contents 1 Introduction.........................................................................................................1 About this document.........................................................................................1 Audience.........................................................................................................1 Related Documentation.....................................................................................1 Technical Support ............................................................................................1 2 Components .........................................................................................................3 Overview.........................................................................................................3 Selecting Components ......................................................................................4 Component Types ..................................................................................4 Component List......................................................................................4 Matching the Name String.......................................................................5 Removing Selected Components ..............................................................5 Adding/Editing Components...............................................................................6 Add Hypothetical Component/Edit Component ...........................................6 Identification Tab ...................................................................................6 Critical Tab............................................................................................7 Other Tab..............................................................................................9 Editing Database Components .................................................................9 Estimating Unknown Properties.............................................................. 10 Organizing the Component List ........................................................................ 11 Changing the Components .................................................................... 11 Combining Components ........................................................................ 11 Binary Interaction Parameters ......................................................................... 11 3 Scenarios ...........................................................................................................15 Overview....................................................................................................... 15 Scenario Manager .......................................................................................... 16 Adding/Editing Scenarios................................................................................. 17 General Tab......................................................................................... 18 Constraints Tab.................................................................................... 19 Sources Tab ........................................................................................ 20 Estimates Tab...................................................................................... 21 Scenario Tools ............................................................................................... 23 Adding Single Source Scenarios ............................................................. 23 4 Pipe Network......................................................................................................25 Overview....................................................................................................... 25 Pipe Manager................................................................................................. 25 Ignoring/Restoring Pipes ................................................................................. 26 Connections Tab .................................................................................. 27 Dimensions Tab ................................................................................... 29 ii Contents Fittings Tab ......................................................................................... 30 Heat Transfer Tab ................................................................................ 32 Methods Tab........................................................................................ 33 Summary Tab...................................................................................... 37 Multiple Editing .................................................................................... 38 Pipe Class Editor .................................................................................. 39 5 Nodes.................................................................................................................41 Overview....................................................................................................... 41 Node Manager ............................................................................................... 41 Ignoring/Restoring Nodes................................................................................ 42 Connection Nodes .......................................................................................... 43 Connector ........................................................................................... 43 Flow Bleed........................................................................................... 47 Horizontal Separator............................................................................. 50 Orifice Plate......................................................................................... 56 Tee .................................................................................................... 60 Vertical Separator ................................................................................ 65 Summary Tab...................................................................................... 70 Boundary Nodes............................................................................................. 71 Control Valve....................................................................................... 71 Relief Valve ......................................................................................... 81 Source Tools........................................................................................ 94 Flare Tip ............................................................................................. 95 6 Calculations......................................................................................................101 Starting the Calculations ............................................................................... 101 Efficient Modeling Techniques ........................................................................ 102 Data Entry......................................................................................... 102 Calculation Speed............................................................................... 103 Sizing Calculations ............................................................................. 104 7 Databases ........................................................................................................107 Overview..................................................................................................... 107 Database Features ....................................................................................... 108 Grid Controls ..................................................................................... 108 Maneuvering Through the Table ........................................................... 109 Printing............................................................................................. 109 Adding/Deleting Data.......................................................................... 109 Setting The Password ................................................................................... 110 Pipe Schedule Database Editor....................................................................... 110 Fittings Database Editor ................................................................................ 112 Component Database Editor .......................................................................... 112 Importing Component Data ................................................................. 113 8 Automation ......................................................................................................115 Overview..................................................................................................... 115 Objects ....................................................................................................... 116 Object Hierarchy ................................................................................ 116 The Aspen Flare System Analyzer Type Library ...................................... 117 Object Browser .................................................................................. 117 Contents iii Automation Syntax............................................................................. 120 Examples: Accessing Aspen Flare System Analyzer Object Properties ....... 123 Aspen Flare System Analyzer Object Reference................................................ 126 Application ........................................................................................ 127 Bleed................................................................................................ 128 Bleeds .............................................................................................. 128 Component........................................................................................ 129 Components ...................................................................................... 130 Connector ......................................................................................... 130 Connectors........................................................................................ 131 ControlValve...................................................................................... 132 ControlValves .................................................................................... 133 HorizontalSeparator............................................................................ 133 HorizontalSeparators .......................................................................... 134 Nodes............................................................................................... 134 OrificePlate........................................................................................ 135 OrificePlates ...................................................................................... 135 Pipe.................................................................................................. 136 Pipes ................................................................................................ 138 ReliefValve ........................................................................................ 139 ReliefValves....................................................................................... 141 Scenario ........................................................................................... 141 Scenarios .......................................................................................... 142 Solver............................................................................................... 142 Tee .................................................................................................. 143 Tees ................................................................................................. 144 Tip ................................................................................................... 145 Tips.................................................................................................. 146 VerticalSeparator ............................................................................... 146 VerticalSeparators.............................................................................. 147 Example – Automation In Visual Basic ............................................................ 147 Updating Automation Files From Previous Versions........................................... 155 9 Theoretical Basis..............................................................................................157 Pressure Drop.............................................................................................. 157 Pipe Pressure Drop Method.................................................................. 157 Fittings Pressure Change Methods ........................................................ 165 Vapor-Liquid Equilibrium............................................................................... 175 Compressible Gas............................................................................... 175 Vapor Pressure .................................................................................. 175 Soave Redlich Kwong.......................................................................... 176 Peng Robinson................................................................................... 177 Physical Properties ....................................................................................... 178 Vapor Density.................................................................................... 178 Liquid Density.................................................................................... 178 Vapor Viscosity .................................................................................. 179 Liquid Viscosity .................................................................................. 179 Liquid Phase Mixing Rules for Viscosity.................................................. 181 Thermal Conductivity.......................................................................... 182 Enthalpy ........................................................................................... 182 Noise.......................................................................................................... 186 iv Contents A File Format.......................................................................................................189 Import/Export Details ................................................................................... 189 Process Descriptions........................................................................... 189 Definition File Formats ........................................................................ 192 Recognized Objects and Items ............................................................. 197 Report Files Format ...................................................................................... 215 B References .......................................................................................................221 C Glossary of Terms ............................................................................................223 Adiabatic Flow ............................................................................................. 223 Choked Flow................................................................................................ 223 Critical Pressure........................................................................................... 223 Critical Temperature..................................................................................... 223 Dongle........................................................................................................ 223 Equivalent Length ........................................................................................ 223 Isothermal Flow........................................................................................... 224 MABP.......................................................................................................... 224 Mach Number .............................................................................................. 224 Node .......................................................................................................... 224 Reduced Pressure......................................................................................... 224 Reduced Temperature................................................................................... 224 Scenario ..................................................................................................... 224 Schedule..................................................................................................... 225 Security Device............................................................................................ 225 Source........................................................................................................ 225 Static Pressure............................................................................................. 225 Tailpipe....................................................................................................... 225 Total Pressure.............................................................................................. 225 Velocity Pressure.......................................................................................... 225 Index ..................................................................................................................226 1 Introduction 1 1 Introduction This section provides information on the following topics: - About this Document - Audience - Related Documentation - Technical Support About this document The guide provides a detailed description of all the features and functionality within Aspen Flare System Analyzer (previously called Aspen FLARENET). Audience This guide is intended for process and process systems engineers. Related Documentation Title Content Aspen Flare System Analyzer Getting Started Guide Tutorials covering the basic use of Aspen Flare System Analyzer Technical Support AspenTech customers with a valid license and software maintenance agreement can register to access the online AspenTech Support Center at: http://support.aspentech.com This Web support site allows you to: - Access current product documentation - Search for tech tips, solutions and frequently asked questions (FAQs) - Search for and download application examples 2 1 Introduction - Search for and download service packs and product updates - Submit and track technical issues - Send suggestions - Report product defects - Review lists of known deficiencies and defects Registered users can also subscribe to our Technical Support e-Bulletins. These e-Bulletins are used to alert users to important technical support information such as: - Technical advisories - Product updates and releases Customer support is also available by phone, fax, and email. The most up-to- date contact information is available at the AspenTech Support Center at http://support.aspentech.com. 2 Components 3 2 Components This section provides information on the following topics: - Overview - Selecting Components - Adding/Editing Components - Organizing the Component List - Binary Interaction Parameters Overview Data for all components that will be used in the simulation must be selected before the sources are defined. These components may be taken from the standard component library, or you may define your own components, known as hypothetical components. You may select components from Component Manager, which can be accessed by clicking Components in the Build group on the Home tab of the Ribbon. The Component Manager window will be displayed: 4 Fig 2.1 This view displays all of the Components, and provides various tools which you can use to add and edit database and hypothetical components. Selecting Components Component Types You may filter the list of available components to include only those belonging to a specific family. respectively, Invert example, if only Hydrocarbons Invert, then these two check boxes would be cleared, while the remaining check boxes would be Component List Components can be chosen from the to the Selected C 1 Arrow Keys component. 2 PageUp/PageDown page forward or backward. This view displays all of the Available Components and Selected , and provides various tools which you can use to add and edit and hypothetical components. Selecting Components Component Types You may filter the list of available components to include only those belonging to a specific family. All and None turn all of the filters on and off, Invert toggles the status of each check box individually. As an example, if only Hydrocarbons (HC) and Misc were selected, and you clicked , then these two check boxes would be cleared, while the remaining check boxes would be selected. Component List Components can be chosen from the Available Components Components list, using one of the following methods: – Use the arrow keys to move the highlight up or down one PageUp/PageDown - Press these keyboard keys to advance an entire page forward or backward. 2 Components Selected , and provides various tools which you can use to add and edit You may filter the list of available components to include only those belonging and off, box individually. As an were selected, and you clicked , then these two check boxes would be cleared, while the remaining list, and added list, using one of the following methods: to move the highlight up or down one Press these keyboard keys to advance an entire 2 Components 5 3 Home/End - Press Home to move to the start of the list and End to move to the end of the list. 4 Scroll Bar - Use the scroll bar to move up and down through the list. Note: You can select multiple components by using the SHIFT or CTRL keys as you select components. 5 Enter the component name from keyboard - When you type a letter or number, you will move to the next component in the list which starts with that character. If you repeatedly enter the same character, you will cycle through all of the components which start with that character. To add a component, you must first highlight it (by moving through the list until that component is highlighted) and click to select, then transfer it by double-clicking it or clicking Add. Matching the Name String The interpretation of your input is limited to the Component Types which are checked. Another way to add components is through the Selection Filter feature. The Selection Filter box accepts keyboard input, and is used to locate the component(s) in the current list that best matches your input. You may use wildcard characters as follows: ? - Represents a single character. * - Represents a group of characters of undefined length. Any filter string has an implied * character at the end. Some examples are shown here: Filter Result methan methanol, methane, etc. *anol methanol, ethanol, propanol, etc. ?-propanol 1-propanol, 2-propanol *ane methane, ethane, propane, i-butane, etc. As you are typing into the Selection Filter box, the component list is updated, matching what you have presently typed. You may not have to enter the complete name or formula before it appears in the component list. Removing Selected Components You can remove any component from the Selected Components list:1 Highlight the component(s) you want to delete. 2 Click Remove. You can select multiple components using Shift-click and Ctrl-click to remove them all. Once the components are removed from the list, any source compositions that used this component will be normalized. 6 Adding/Editing Components To create a new component (hypothetical), click components are set up in th Previously defined hypothetical components can be changed by selecting them in the Selected Component Add Hypothetical Component/Edit Component Upon clicking either Identification Tab The minimum data requirements for creating a component are specified here Fig 2.2 Component Types - Hydrocarbon ( - Miscellaneous ( - Amine Adding/Editing Components To create a new component (hypothetical), click Hypothetical components are set up in the same manner as database components. Previously defined hypothetical components can be changed by selecting Selected Components list and clicking Edit. Add Hypothetical Component/Edit Component Upon clicking either Hypothetical or Edit, the Component Editor Identification Tab The minimum data requirements for creating a component are specified here Component Types Hydrocarbon (HC) Miscellaneous (Misc) 2 Components Adding/Editing Components Hypothetical. Hypothetical e same manner as database components. Previously defined hypothetical components can be changed by selecting mponent Editor opens up. The minimum data requirements for creating a component are specified here: 2 Components 7 - Alcohol - Ketone - Aldehyde - Ester - Carboxylic Acid (Carbacid) - Halogen - Nitrile - Phenol - Ether The following fields are available on this tab: Input Field Description Name An alphanumeric name for the component (e.g. - Hypo -1). Type The type of component (or family) can be selected from the list provided. There is a wide selection of families to choose from, which allows better estimation methods to be chosen for that component. ID The ID number is provided automatically for new components and cannot be edited. Mol. Wt. The molecular weight of the component. NBP The normal boiling point of the component. Std. Density The density of the component as liquid at 1 atm and 60 F. Watson K The Watson characterization factor. Critical Tab Critical properties are specified here. 8 Fig 2.3 The following field Input Field Critical Pres. Critical Temp. Critical Volume Char. Volume Acentric Factor Acent. Fact. (SRK) The following fields are available on this tab: Description The critical pressure of the component. If the component represents more than a single real component, the pseudo critical pressure should be used. The critical temperature of the component. If the component represents more than a single real component, the pseudo critical temperature should be used. The critical volume of the component. If the component represents more than a single real component, the pse critical volume should be used. The characteristic volume of the component. If the component represents more than a single real component, the pseudo characteristic volume should be used. The acentric factor of the component. Acent. Fact. (SRK) The Soave-Redlich-Kwong acentric factor of the component (also called the COSTALD Acentricity). 2 Components The critical pressure of the component. If the component represents more than a single real component, the pseudo e of the component. If the component represents more than a single real component, the pseudo The critical volume of the component. If the component represents more than a single real component, the pseudo The characteristic volume of the component. If the component represents more than a single real component, the pseudo Kwong acentric factor of the component 2 Components Other Tab Coefficients for the polynomial equations for the prediction of Ideal Gas thermodynamic properties and parameters for the vi specified here: Fig 2.4 The following fields are available on this tab: Input Field Hi A, Hi B, Hi C, Hi D, Hi E, and Hi F Entropy Coef. Viscosity A and Viscosity B Editing Database Components If you want to change the data for one of the database components, e.g. Methane, you will find that component will display Other Tab Coefficients for the polynomial equations for the prediction of Ideal Gas thermodynamic properties and parameters for the viscosity calculations are The following fields are available on this tab: Description Hi A, Hi B, Hi C, Hi D, Hi E, and The coefficients for the ideal gas specific enthalpy equation: The coefficient for the entropy equation. Viscosity A and Viscosity B Viscosity coefficients used in the NBS Method (Ely and Hanley, 1983). Editing Database Components If you want to change the data for one of the database components, e.g. Methane, you will find that opening the Component Editor for this component will display read-only values that cannot be changed. H i A BT CT 2 DT 3 ET 4 FT + + + + + = 9 Coefficients for the polynomial equations for the prediction of Ideal Gas scosity calculations are The coefficients for the ideal gas specific enthalpy nt for the entropy equation. Viscosity coefficients used in the NBS Method (Ely If you want to change the data for one of the database components, e.g. for this values that cannot be changed. FT 5 10 Fig 2.5 In order to update the data for a database component it must first be changed to a hypothetical comp At the very minimum, you need to specify the Molecular Weight. However, it is a good practice to specify at least two of the following properties: - Molecular Weight ( - Normal Boiling Point ( - Standard Density ( This is done by clicking Estimating Unknown Properties If any of the above data is unknown, click properties. Supply as many properties as are known, so accurate as possible. In order to update the data for a database component it must first be changed to a hypothetical component. At the very minimum, you need to specify the Molecular Weight. However, it is a good practice to specify at least two of the following properties: Molecular Weight (Mol. Wt.) Normal Boiling Point (NBP) Standard Density (Std. Density) clicking Hypothetical in the Component Editor Estimating Unknown Properties If any of the above data is unknown, click Estimate to fill-in the unknown Supply as many properties as are known, so that the estimation can be as accurate as possible. 2 Components In order to update the data for a database component it must first be At the very minimum, you need to specify the Molecular Weight. However, it is a good practice to specify at least two of the following properties: Component Editor. in the unknown that the estimation can be as 2 Components 11 Organizing the Component List The Selected Components list can be organized in the following different ways. Changing the Components You can switch the components in the Selected Components list with the ones in the Available Components list while maintaining the source mole fractions. In Component Manager, select the components in both the Selected Components and the Available Components lists. Click Switch to switch the two components. Combining Components Multiple components can be combined and represented by a single component to reduce the number of components in the model. To combine multiple components: 1 Select the components you want to combine by Ctrl-clicking them in the Selected Components list. 2 Click Combine. The Component Combination window will be displayed, and ask you to select which basis should be used. The highlighted component in the box at the upper part of the window is the target component to combine your selected components into. Once the basis has been selected the combined components will update each source in the model by summing the composition of all of the combined components and assigning it to the target component. Reducing the number of components in this way is useful since it can greatly speed the calculations. This is especially true where a model contains sources defined with a long list of hypothetical components. For example, consider a model containing the hypothetical components BP200, BP225, BP250, BP275, BP300 boiling at 200°C, 225°C, 250°C, 275°C and 300°C respectively. Since these components are likely to stay in the liquid phase throughout the flare system, they may be combined into a single component, BP250 without significant loss of accuracy. As another example, in a purely gas phase flare system it is possible to combine isomers such as i- Butane and n-Butane into a single component n-Butane without compromising results. Binary Interaction Parameters Binary Interaction Coefficients, often known as K IJ ’s, are factors that are used in equations of state to better fit the interaction between pairs of components and hence improve the accuracy of VLE calculations. You are allowed to specify binary interaction parameters for the Peng Robinson and Soave 12 Redlich Kwong VLE methods or to estimate them through the tab of the Component Manager Fig 2.6 To define binary interaction coefficients Robinson or Soave Redlich Kwong at the top of the window. Note: Binary interac Compressible Gas Individual binary interaction parameters are set by selecting the required entry in the matrix and typing in the new value. Note: The matrix is symmetri an entry will also update the corresponding entry in the table. E.g. updating the entry in the Methane column, Propane row will also update the entry in the Propane column, Methane row. Individual binary required entry in the matrix and clicking method is based on the components critical volume. It is possible to set several bina either by Ctrl-clicking the two corners of a rectangular area in the matrix. The selected entries can then be estimated by clicking by clicking Zero HC Redlich Kwong VLE methods or to estimate them through the Binary Coeffs Component Manager as shown here. To define binary interaction coefficients, first select either the Soave Redlich Kwong VLE method from the VLE Method at the top of the window. Binary interaction coefficients are not used by either the Gas or Vapor Pressure VLE methods at present Individual binary interaction parameters are set by selecting the required entry in the matrix and typing in the new value. The matrix is symmetrical i.e. K JI is the same value as K an entry will also update the corresponding entry in the table. E.g. updating the entry in the Methane column, Propane row will also update the entry in the Propane column, Methane row. Individual binary interaction parameters may be estimated by selecting the required entry in the matrix and clicking Estimate HC. The estimation method is based on the components' boiling point, standard liquid density and It is possible to set several binary interaction parameters at the same time clicking the two corners of a rectangular area in the matrix. The selected entries can then be estimated by clicking Estimate HC Zero HC-HC. 2 Components Binary Coeffs first select either the Peng VLE Method list tion coefficients are not used by either the VLE methods at present. Individual binary interaction parameters are set by selecting the required is the same value as K JI , and updating an entry will also update the corresponding entry in the table. E.g. updating the entry in the Methane column, Propane row will also update the entry in interaction parameters may be estimated by selecting the . The estimation boiling point, standard liquid density and ry interaction parameters at the same time clicking the two corners of a rectangular area in the matrix. The HC or set to 0.0 2 Components 13 Clicking Reset All causes all interaction parameters to be set to their default values. Generally this is 0.0 for hydrocarbon components with non zero values being supplied only for common polar components. If the Auto Estimate check box is selected, then the interaction parameters for new components are automatically estimated as they are added to the model. 14 2 Components 3 Scenarios 15 3 Scenarios This section provides information on the following topics: - Overview - Scenario Manager - Adding/Editing Scenarios - Scenario Tools Overview A scenario defines a set of source conditions (flows, compositions, pressures and temperatures) for the entire network. The design of a typical flare header system will be comprised of many scenarios for each of which the header system must have adequate hydraulic capacity. Typical scenarios might correspond to: - Plant wide power failure - Plant wide cooling medium or instrument air failure - Localized control valve failure - Localized fire or Depressurization The scenario management allows you to simultaneously design and rate the header system for all of the possible relief scenarios. Note: Although the major relief scenarios will normally constrain the size of the main headers, care should be taken in the evaluation of velocities in the individual relief valve tailpipes and sub headers. When looking at relief valves which might operate alone, lower back pressures in the main headers may lead to localized high velocities and consequently choked flow in the tail pipes. As well as having different source conditions, each scenario can have unique design limitations that will be used either to size the pipes or to highlight problems when an existing flare system is being rated. For example, a Mach number limit of 0.30 might be applied for normal flaring compared to a Mach number limit of 0.50 or greater at the peak flows encountered during plant blowdown. 16 3 Scenarios Scenario Manager Scenarios can also be selected by selecting the scenario from the list in Run group on the Home tab of the Ribbon. Fig 3.1 Scenarios are managed via the Scenario Manager. This window allows you to add, edit or delete scenarios as well as to select the current scenario for which scenario specific data is displayed. All cases have at least one scenario. To access the Scenario Manager On the Home tab, in Build, click Scenarios. Scenario Manager will be displayed: 3 Scenarios Fig 3.2 The Scenario Manager current scenario. Several buttons are available: Button Clone Edit Delete Current Close Adding/Editing Scenarios Aspen Flare System Analyzer has no pre scenarios which can To add a scenario, then click Clone To edit a scenario, highlight it, and then click The Scenario Editor Scenario Manager displays all scenarios in the case, and indicates the current scenario. Several buttons are available: Description Clones the highlighted scenario and adds a new scenario to the Scenarios list. Edits the highlighted scenario. Removes the currently highlighted scenario. There must always be at least one scenario in the case. To make a scenario the current one, highlight the appropriate scenario, and then click Current. Closes the Scenario Manager. Adding/Editing Scenarios Aspen Flare System Analyzer has no pre-programmed limits on the number of scenarios which can be defined within a single case. To add a scenario, highlight a existing scenario in the Scenarios in the Scenario Manager. To edit a scenario, highlight it, and then click Edit. The Scenario Editor will be displayed. 17 displays all scenarios in the case, and indicates the es the highlighted scenario and adds a new scenario to Removes the currently highlighted scenario. There must rent one, highlight the appropriate Adding/Editing Scenarios programmed limits on the number of Scenarios list, and 18 General Tab You may provide the following information on the Fig 3.3 Data Name System Back Pres General Tab You may provide the following information on the General tab: Description An alphanumeric description of the scenario (e.g. Power Failure). System Back Pres. The system back pressure at the Flare Tip exit. Thi normally be atmospheric pressure, but can be set to represent system design conditions at the exit point. If left empty, the value on the Calculation Options Editor will be used. The minimum value is 0.01 bar (absolute pressure). 3 Scenarios tab: An alphanumeric description of the scenario (e.g. Power ip exit. This will normally be atmospheric pressure, but can be set to represent system design conditions at the exit point. If left empty, the will be used. The minimum value is 0.01 bar (absolute pressure). 3 Scenarios Constraints Tab This tab requires the following information for both headers and tailpipes. Fig 3.4 Tailpipes are indicated by the Pipe Editor. You may provide different design information ( Noise at 1 m, Vapor Vel Tailpipes. Any boxes may be left empty, in which case they will be ignored. Data Mach Number Vapor Velocity Liquid Velocity Constraints Tab is tab requires the following information for both headers and tailpipes. Tailpipes are indicated by the Tailpipe field on the Connections . You may provide different design information (Mach Number Vapor Velocity, Liquid Velocity) for the Headers . Any boxes may be left empty, in which case they will be ignored. Description The maximum allowable Mach number for all pipe segments. Calculated values that exceed this number will be highlighted in the results. The maximum allowable vapor velocity. Calculated velocities that exceed this value will be indicated in the results. The maximum allowable liquid velocity. Calculated velocities that exceed this value will be indicated in the results. 19 is tab requires the following information for both headers and tailpipes. Connections box of the Mach Number, Headers and . Any boxes may be left empty, in which case they will be ignored. The maximum allowable Mach number for all pipe segments. e highlighted in the The maximum allowable vapor velocity. Calculated velocities that The maximum allowable liquid velocity. Calculated velocities that 20 3 Scenarios Rho V2 The density times the velocity square. This value is normally used as a limiting factor to prevent erosion. Noise The maximum allowable sound pressure level at a distance of 1 meter for all pipe segments. This is an average value over the length of the pipe. Calculated values that exceed this specification will be highlighted in the results. Check Vel. Constraint Specify either Mixture Velocity or Phase Superficial Velocity is used while checking the velocity constraints for design in a scenario. Note: Whilst rating the network you may define a Mach number constraint of 1.00, in order to highlight only choked flow conditions. This is not recommended for design calculations where a more reasonable value such as 0.5 or 0.7 will lead to a more rapid solution towards the maximum allowable back pressure constraints. Sources Tab If a source is ignored, the MABP constraint is ignored by sizing calculations. When you select the Sources tab, you will see that all sources are displayed on this tab. Note: If you are setting up a new case, the Sources tab will not show any sources. 3 Scenarios Fig 3.5 This tab is useful in that you can easily toggle whether or not individual sources are to be included in the current scenario, unnecessarily delete sources or set the flow of a source to zero. Estimates Tab The Estimates tab allows some control over the selection and initialization of flowrates for pipes which are to be used as tears in the solution of loo systems. The use to which each field is put is dependent upon the Analyzer setting on the The check boxes in the pipes from being used as tears being used as a tear or clear it to allow it. This setting has no effect if the Simultaneous structural analyzer is used. When the Convergent recommends a tear locati If the structural analyzer does find that the pipe may be a valid tear location then this value is ignored. This tab is useful in that you can easily toggle whether or not individual sources are to be included in the current scenario, without having to either unnecessarily delete sources or set the flow of a source to zero. Estimates Tab tab allows some control over the selection and initialization of flowrates for pipes which are to be used as tears in the solution of loo systems. The use to which each field is put is dependent upon the setting on the Solver tab of Calculation Options Editor The check boxes in the No Tear column of the table allow you to prevent pipes from being used as tears - select the check box to prevent a pipe from being used as a tear or clear it to allow it. This setting has no effect if the structural analyzer is used. Convergent structural analyzer is used, the Molar Flow recommends a tear location and initial value for the flow at the tear location. If the structural analyzer does find that the pipe may be a valid tear location then this value is ignored. 21 This tab is useful in that you can easily toggle whether or not individual without having to either unnecessarily delete sources or set the flow of a source to zero. tab allows some control over the selection and initialization of flowrates for pipes which are to be used as tears in the solution of looped systems. The use to which each field is put is dependent upon the Structure Calculation Options Editor. column of the table allow you to prevent t the check box to prevent a pipe from being used as a tear or clear it to allow it. This setting has no effect if the Molar Flow column on and initial value for the flow at the tear location. If the structural analyzer does find that the pipe may be a valid tear location, 22 When the Simultaneous is used to seed th long as the structural analysis succeeds but the pipe will not necessarily be selected as a tear pipe. In the event that the structural analysis fails with any Molar Flow estimates Fig 3.6 Since the Simultaneous performance than the specify information on the improving the speed of convergence of the model. In the event that a model proves problematic to converge, a number of additional columns are available to tune the convergence algorithms. These may be exposed by stretching the view horizontally. The Max. Step column defines the maximum change to the flow in a tear pipe over a single iteration whilst the constrain the flow in a tear pipe. Not all these values are used by all the Solver algorithms. Simultaneous structural analyzer is used, the Molar Flow is used to seed the analyzer. This value will always impact the initialization as long as the structural analysis succeeds but the pipe will not necessarily be selected as a tear pipe. In the event that the structural analysis fails with any estimates, the model will be initialized by the default values. Simultaneous structural analyzer generally offers better performance than the Convergent analyzer it will rarely be necessary to specify information on the Estimates tab other than for the pur improving the speed of convergence of the model. In the event that a model proves problematic to converge, a number of additional columns are available to tune the convergence algorithms. These may be exposed by stretching the view horizontally. column defines the maximum change to the flow in a tear pipe over a single iteration whilst the Max. Flow and Min. Flow constrain the flow in a tear pipe. Not all these values are used by all the algorithms. 3 Scenarios Molar Flow column e analyzer. This value will always impact the initialization as long as the structural analysis succeeds but the pipe will not necessarily be selected as a tear pipe. In the event that the structural analysis fails with any will be initialized by the default values. structural analyzer generally offers better analyzer it will rarely be necessary to tab other than for the purpose of improving the speed of convergence of the model. In the event that a model proves problematic to converge, a number of additional columns are available to tune the convergence algorithms. These may be exposed by stretching the column defines the maximum change to the flow in a tear Min. Flow columns constrain the flow in a tear pipe. Not all these values are used by all the Loop 3 Scenarios 23 Max. Step Max. Flow Min. Flow Newton-Raphson 3 3 3 Broyden 3 3 3 Force Convergent Conjugate Gradient Minimisation Quasi-Newton Minimization Scenario Tools The complete analysis of a flare system should ideally include analysis of the system for the scenarios in which each source relieves on its own. For a large network with many sources, it can become tedious to define each of these scenarios. These can automatically be added to your model as follows. Adding Single Source Scenarios Click Source Tools from the Tools group on the Home tab of the Ribbon, then select Add Single Source Scenarios or use the hot key combination Alt, H, U, A. Click OK for the message that pops up. This will analyze your model and add a scenario for each source that has a non-zero flow rate defined in at least one scenario. Source data will be copied from the scenario in which it has the highest flow rate. 24 3 Scenarios 4 Pipe Network 25 4 Pipe Network This section provides information on the following topics: - Overview - Pipe Manager - Ignoring/Restoring Pipes - Multiple Editing Overview The pipe network comprises a series of interconnected pipes. These pipes can be added, edited and deleted from the Pipe Manager. Pipe Manager To access the Pipe Manager, click Pipes in the Build group on the Home tab of the Ribbon. 26 Fig 4.1 The following buttons are available: Button Description Add Adds a new pipe segment. This new pipe will be named with a number depending upon the number of pipes already ad Edit Edits the currently highlighted pipe segment. Delete Removes the currently highlighted pipe segment. Close Closes the Ignoring/Restoring Pipes When you ignore a single pipe, all upstream pipes are automatically ignored. You can ignore single or multiple pipes within the model. When you ignore a single pipe, all upstream nodes are automatically ignored. This enables you to do what if type calculations, where part of the network can be excluded from the calculation without the need appropriate nodes. To ignore a pipe: 1 Open the Pipe Editor 2 On the Connections The following buttons are available: Description Adds a new pipe segment. This new pipe will be named with a number depending upon the number of pipes already added. Edits the currently highlighted pipe segment. Removes the currently highlighted pipe segment. Closes the Pipe Manager. Ignoring/Restoring Pipes When you ignore a single pipe, all upstream pipes are automatically ignored. ignore single or multiple pipes within the model. When you ignore a single pipe, all upstream nodes are automatically ignored. This enables you to type calculations, where part of the network can be excluded from the calculation without the need for deletion and reinstallation of the appropriate nodes. To ignore a pipe: Pipe Editor window of the pipe that you want to ignore. Connections tab, select the Ignore check box. 4 Pipe Network Adds a new pipe segment. This new pipe will be named with a number Ignoring/Restoring Pipes When you ignore a single pipe, all upstream pipes are automatically ignored. ignore single or multiple pipes within the model. When you ignore a single pipe, all upstream nodes are automatically ignored. This enables you to type calculations, where part of the network can be excluded from for deletion and reinstallation of the window of the pipe that you want to ignore. 4 Pipe Network 27 Fig 4.2 To restore a pipe that has previously been ignored: 1 Open the Pipe Editor window of the pipe that you want to restore. 2 On the Connections tab, clear the Ignore check box. Connections Tab The name of the pipe segment and connectivity information is specified here. 28 Fig 4.3 The following fields are available on this tab: Input Data Description Name An alphanumeric description of the pipe segment. Location An alphanu segment. Upstream Node This is the name of the node upstream of the pipe. The list allows you to select from a list of existing unconnected nodes in the model. Downstream Node This is the name you to select from a list of existing unconnected nodes in the model. Tailpipe This list allows you to select whether the pipe should be treated as a tailpipe. If set to option is selected in the pressure drop for this pipe will be calculated using the rated flow in place of the relieving flow rate. Ignore This check calculation nodes and pipes will be ignored during calculations. Fitting Loss The fitting loss for the pipe segment. You cannot change the value shown in this box. Instead, calculated value on the be updated by clicking The following fields are available on this tab: Description An alphanumeric description of the pipe segment. An alphanumeric description of the location within the plant for the segment. This is the name of the node upstream of the pipe. The list allows you to select from a list of existing unconnected nodes in the model. This is the name of the node upstream of the pipe. The list allows you to select from a list of existing unconnected nodes in the model. This list allows you to select whether the pipe should be treated as a tailpipe. If set to Yes and the Rated Flow for Tailpip option is selected in the Calculation Options dialog box, the pressure drop for this pipe will be calculated using the rated flow in place of the relieving flow rate. This check box may be selected to remove the pipe from calculations temporarily. When selected the pipe and all upstream nodes and pipes will be ignored during calculations. The fitting loss for the pipe segment. You cannot change the value shown in this box. Instead, calculated value on the be updated by clicking Link or Paste. 4 Pipe Network meric description of the location within the plant for the This is the name of the node upstream of the pipe. The list allows you to select from a list of existing unconnected nodes in the model. of the node upstream of the pipe. The list allows you to select from a list of existing unconnected nodes in the model. This list allows you to select whether the pipe should be treated as a Rated Flow for Tailpipes calculation dialog box, the pressure drop for this pipe will be calculated using the rated flow in box may be selected to remove the pipe from s temporarily. When selected the pipe and all upstream nodes and pipes will be ignored during calculations. The fitting loss for the pipe segment. You cannot change the value shown in this box. Instead, calculated value on the Fittings tab can 4 Pipe Network You have the option of modeling a pipe segment as a main header or a tailpipe. The ability to classify a pipe as either a tailpipe or a header allows you to perform calculations in which the pressure drop for tailpi determined by the rated flow and that for headers is determined by the nominal flow. This is in accordance with API In the Scenario Editor Vapor and Liquid Velocities headers and the tailpipes. Dimensions Tab The physical dimensions and characteristics of the pipe segment are specified here. Fig 4.4 The following fields are available on this tab: Input Data Length You have the option of modeling a pipe segment as a main header or a tailpipe. The ability to classify a pipe as either a tailpipe or a header allows you to perform calculations in which the pressure drop for tailpi determined by the rated flow and that for headers is determined by the nominal flow. This is in accordance with API-RP-521. Scenario Editor, you can set design limits for the Mach Number Liquid Velocities, Rho V2 and Noise separately for the main headers and the tailpipes. Dimensions Tab The physical dimensions and characteristics of the pipe segment are specified The following fields are available on this tab: Description The physical length of the pipe segment. This length is used in association with the fittings loss coefficients to calculate the equivalent length of the pipe. If you have equivalent length data for your network, enter this data here as the sum of the actual 29 You have the option of modeling a pipe segment as a main header or a tailpipe. The ability to classify a pipe as either a tailpipe or a header allows you to perform calculations in which the pressure drop for tailpipes is determined by the rated flow and that for headers is determined by the Mach Number, ly for the main The physical dimensions and characteristics of the pipe segment are specified the pipe segment. This length is used in association with the fittings loss coefficients to calculate the equivalent length of the pipe. If you have equivalent length data for your network, enter this data here as the sum of the actual 30 4 Pipe Network Input Data Description length plus the equivalent length of the fittings and enter zero for the fittings loss coefficients. Elevation Change A positive elevation indicates that the outlet is higher than the inlet. Material The pipe material, either Carbon Steel or Stainless Steel. Roughness The surface roughness of the pipe segment. Whenever a material is selected, the absolute roughness is initialized to the default value for the material as defined on the Preferences view. Thermal Conductivity The thermal conductivity of the pipe wall. This is used by the heat transfer calculations when these are enabled. Nominal Diameter The nominal pipe diameter used to describe the pipe size. For pipes with a nominal diameter of 14 inches or more, this will be the same as the outside diameter of the pipe. Schedule Select a schedule number from the list, you will be able to select a nominal pipe diameter from the pipe databases. It will not be necessary to specify the Internal Diameter or the Wall Thickness for the pipe. Internal Diameter The pipe diameter used for the pressure drop calculations. Wall Thickness The thickness of the pipe wall. Valid values are any positive number or zero. Use Class Select Yes to restrict the pipe sizes to those defined by the Pipe Class. Sizeable If you wish the pipe segment to be resized by sizing calculations, Yes should be selected. For example, a model of a network containing a representation of the knockout drum, as a pipe segment would normally leave this unchecked such that sizing calculations for the pipes would not change the knockout drum size. Schedule Numbers Carbon Steel: 10, 20, 30, 40, 60, 80, 100, 120, 140, 160, STD, XS, XXS, User Stainless Steel: 5S, 10S, 40S, 80S Fittings Tab A list of pipe fittings may be added to the pipe segment. These fittings will be modeled as an additional equivalent length applied linearly over the physical length of the pipe segment. 4 Pipe Network Fig 4.5 The following fields are available on this tab: Input Data Length Multiplier Fittings Loss From the Database Fitting then click Add to m select as many fittings as required. The final fitting loss equation, which will be a sum of all the selected fittings, will appear in a display field underneath the Selected Fitting Click Link to transfer the coefficients for this equation into the field on the Connections Click Paste to transfer the coefficients for the fitting equation into the Fittings Loss field To remove the selected fitting individually, select the fitting and click The following fields are available on this tab: Description The length of the pipe is multiplied by this value to determine the equivalent length used for the pressure drop calculation. If left blank then the value on the Calculation Options Editor This option is useful for making an allowance for bends and other fittings if these are not known. The fittings "K" factor is calculated from the following equation in which Ft is the friction factor for fully developed turbulent flow: K = A + BFt Database Fittings list, select the appropriate type of fitting, and to move the selection to the Selected Fittings select as many fittings as required. The final fitting loss equation, which will be a sum of all the selected fittings, will appear in a display field underneath Selected Fittings list. to transfer the coefficients for this equation into the Connections tab, while maintaining the list of fittings. to transfer the coefficients for the fitting equation into the field. The selected list of fittings will not be retained. To remove the selected fitting individually, select the fitting and click 31 ue to determine the equivalent length used for the pressure drop calculation. If left Calculation Options Editor is used. This option is useful for making an allowance for bends and other The fittings "K" factor is calculated from the following equation in is the friction factor for fully developed turbulent flow: list, select the appropriate type of fitting, and s list. You can select as many fittings as required. The final fitting loss equation, which will be a sum of all the selected fittings, will appear in a display field underneath to transfer the coefficients for this equation into the Fittings Loss , while maintaining the list of fittings. to transfer the coefficients for the fitting equation into the of fittings will not be retained. To remove the selected fitting individually, select the fitting and click Delete. 32 Note: The network cannot be sized correctly if you specify equivalent length data to model fittings losses, since the equivalent length of a a function of the pipe diameter and will therefore be incorrect when the diameters change. Heat Transfer Tab The pipe segment may perform calculations taking into account heat transfer with the external air. Fig 4.6 The following field Input Data External Conditions Group External Medium Temperature The network cannot be sized correctly if you specify equivalent length data to model fittings losses, since the equivalent length of any pipe fitting is a function of the pipe diameter and will therefore be incorrect when the diameters change. Heat Transfer Tab The pipe segment may perform calculations taking into account heat transfer with the external air. The following fields are available on this tab: Description External Conditions Group Select the external medium. Two options are currently available: Air or Sea Water Enter the temperature of the external air. If this field is left blank, the global value set via the Options Editor is used. 4 Pipe Network The network cannot be sized correctly if you specify equivalent length ny pipe fitting is a function of the pipe diameter and will therefore be incorrect when the The pipe segment may perform calculations taking into account heat transfer Select the external medium. Two options are Sea Water. Enter the temperature of the external air. If this field the global value set via the Calculation 4 Pipe Network 33 Input Data Description External Medium Velocity Enter the velocity of the external medium. If this field is left blank, the global value set via the Calculation Options Editor is used. Heat Transfer Enabled This list selects whether heat transfer calculations are to be performed for the pipe. Furthermore, setting only enables heat transfer calculations if the Enable Heat Transfer option is also selected in the Calculation Options Editor. External Radiative HTC This list selects whether or not the external radiative heat transfer coefficient is included within the heat transfer calculations. Emissivity Enter the fractional Emissivity to be used for radiative heat transfer calculations. Multiple Element Calculation This list selects whether the heat transfer calculation is done using a single element or the same number of elements as the pressure drop calculation. If Yes is selected, the heat transfer calculation sues the same number of elements as the pressure drop calculation Insulation Group Description A brief description to identify the type of pipe insulation. Thickness Supply the insulation thickness. Thermal Conductivity Enter the insulation thermal conductivity. Heating Group Outlet Temp You can explicitly set an outlet temperature for this segment, or leave it blank. A heater in a flare knockout drum is an example of process equipment that may require a fixed outlet temperature. Duty Enter the heating duty and the outlet temperature will be calculated based on the inlet temperature and the defined duty. Methods Tab Calculation methods are specified here. 34 Fig 4.7 The following fields are available on this tab: Input Field Description VLE Method Group VLE Method The options for the Va follows (see The following fields are available on this tab: Description VLE Method Group The options for the Vapor-Liquid Equilibrium calculations are as follows (see Chapter 9 Theoretical Basis for more details): - Compressible Gas - Real Gas relationship. This is only available when the Enthalpy Method on the Options Editor is Ideal Gas. - Peng Robinson - Peng Robinson Equation of State available when the Enthalpy Method on the Options Editor is NOT Ideal Gas. - Soave Redlich Kwong - Soave Redlich Kwong Equation of State. This is available when the Enthalpy Method Calculation Options Editor is NOT Ideal Gas - Vapor Pressure - Vapor Pressure method as described in API Technical Data Book Volume 113. This is available when the Enthalpy Method on the Calculation Options Editor NOT Ideal Gas. - Model Default - If this is selected, the Default method for the VLE method (as defined on the Calculation Options Editor will be used. 4 Pipe Network Liquid Equilibrium calculations are as for more details): This is only on the Calculation Peng Robinson Equation of State. This is on the Calculation Soave Redlich Kwong Equation of Enthalpy Method on the Ideal Gas. Vapor Pressure method as described in API This is available when the Calculation Options Editor is If this is selected, the Default method for the Calculation Options Editor) 4 Pipe Network 35 Input Field Description Pressure Drop Group Horizontal and Inclined Pipes The Horizontal/Inclined methods apply only when you have selected Two-Phase pressure drop. The options are: - Isothermal Gas - This is a compressible gas method that assumes isothermal expansion of the gas as it passes along the pipe. Aspen Flare System Analyzer uses averaged properties of the fluid over the length of the pipe. The outlet temperature from the pipe is calculated by adiabatic heat balance either with or without heat transfer. Pressure losses due to change in elevation are ignored. - Adiabatic Gas - This is a compressible gas method that assumes adiabatic expansion of the gas as it passes along the pipe. As with the Isothermal Gas method, pressure losses due to changes in elevation are ignored. - Beggs & Brill - The Beggs and Brill method is based on work done with an air-water mixture at many different conditions, and is applicable for inclined flow. - Dukler - Dukler breaks the pressure drop in two-phase systems into three components - friction, elevation and acceleration. Each component is evaluated independently and added algebraically to determine the overall pressure drop. - Lockhart Martinelli – Lockhart Martinelli correlations models the two phase pressure drop in terms of a single phase pressure drop multiplied by a correction factor. Acceleration changes are not included. - Beggs and Brill (No Acc.) – The Beggs and Brill methods without the acceleration term. - Beggs and Brill (Homog.) – The Beggs and Brill methods with a homogeneous acceleration term. - Dukler (AGA Head) - Uses the AGA equation for the calculation of the static head term rather than the Eaton equation which can be poor when you have small quantities of liquid in the system. - Model Default - If this is selected, the Default method for the Horizontal/Inclined method (as defined on the Calculation Options Editor) will be used. 36 4 Pipe Network Input Field Description Vertical Pipes The Vertical method applies only when you have selected Two-Phase pressure drop. The options are: - Isothermal Gas - This is a compressible gas method that assumes isothermal expansion of the gas as it passes along the pipe. Aspen Flare System Analyzer uses averaged properties of the fluid over the length of the pipe. The outlet temperature from the pipe is calculated by adiabatic heat balance either with or without heat transfer. Pressure losses due to change in elevation are ignored. - Adiabatic Gas - This is a compressible gas method that assumes adiabatic expansion of the gas as it passes along the pipe. As with the Isothermal Gas method, pressure losses due to changes in elevation are ignored. - Beggs & Brill - Although the Beggs and Brill method was not originally intended for use with vertical pipes, it is nevertheless commonly used for this purpose, and is therefore included as an option for vertical pressure drop methods. For more details, see Chapter 9 Theoretical Basis. - Dukler - Although the Dukler method is not generally applicable to vertical pipes, it is included here to allow comparison with the other methods. - Orkiszewski - This is a pressure drop correlation for vertical, two-phase flow for four different flow regimes - bubble, slug, annular-slug transition and annular mist. For more details, see Appendix A - Theoretical Basis. - Lockhart Martinelli – Lockhart Martinelli correlations models the two phase pressure drop in terms of a single phase pressure drop multiplied by a correction factor. Acceleration changes are not included. - Beggs and Brill (No Acc.) – The Beggs and Brill methods without the acceleration term. - Beggs and Brill (Homog.) – The Beggs and Brill methods with a homogeneous acceleration term. - Model Default - If this is selected, the Default method for the Vertical method (as defined on the Calculation Options Editor) will be used. Elements For two-phase calculations, the pipe segment is divided into a specified number of elements. On each element, energy and material balances are solved along with the pressure drop correlation. In simulations involving high heat transfer rates, many increments may be necessary, due to the non-linearity of the temperature profile. Obviously, as the number of increments increases, so does the calculation time; therefore, you should try to select a number of increments that reflects the required accuracy. 4 Pipe Network 37 Input Field Description Friction Factor Method The Friction Factor Method applies only when you have entered a value for friction factor. The options are: - Round - This method has been maintained primarily for historical purposes in order for older Aspen Flare System Analyzer calculations to be matched. It tends to over predict the friction factor by up to 10% in the fully turbulent region. - Chen - It should always be the method of preference since it gives better predictions at the fully turbulent flow conditions normally found within flare systems. - Model Default - If this is selected, the Default method for the Friction Factor Method (as defined on the Calculation Options Editor) will be used. Static Head Contribution The following options are available: - Include - The static head contribution to total pressure drop in the pipe segments is included. - Ignore Downhill Recovery - The static head recovery term is ignored for downhill sections of pipe. - Ignore - The static head contribution to the pressure drop calculation for all pipe segments is ignored. Include is applied by default. Solver Group Damping Factor The damping factor used in the iterative solution procedure. If this is left blank, the value in the Calculation Options Editor is used. Note: When you are sizing a flare system, the initial pipe diameters may affect the solution when there is a liquid phase and the liquid knockout drum is modeled. You should initially size a network using vapor phase methods. Summary Tab The results of the calculation are displayed. 38 Fig 4.8 Multiple Editing You can edit multiple pipe segments simultaneousl the Pipe Manager pressed. After you have finished selecting pipe segments, click the common Pipe Editor The common pipe editor view differs from that of the single p in the following respects: - Only fields that can be edited in multiple mode are displayed. - The input fields that the value should remain at the pre edit value. - In the following figure of the Length not be changed. We specify new values for the the Thermal Conductivity Sizeable Multiple Editing You can edit multiple pipe segments simultaneously by highlighting them in Pipe Manager with the mouse cursor while keeping the S pressed. After you have finished selecting pipe segments, click Pipe Editor. The common pipe editor view differs from that of the single pipe editor view in the following respects: Only fields that can be edited in multiple mode are displayed. The input fields have an additional entry, *. This entry indicates that the value should remain at the pre edit value. In the following figure of the Dimensions tab; we enter * for the Length and Elevation Change fields to indicate that these must not be changed. We specify new values for the Roughness Thermal Conductivity. We select * for the Use Class Sizeable boxes to indicate that these must be changed. 4 Pipe Network y by highlighting them in Shift key pressed. After you have finished selecting pipe segments, click Edit to open ipe editor view Only fields that can be edited in multiple mode are displayed. have an additional entry, *. This entry indicates tab; we enter * for the fields to indicate that these must Roughness and Use Class and must be changed. 4 Pipe Network Fig 4.9 Pipe Class Editor The Pipe Class Editor nominal diameter, for both calculations. It also allows you to restrict the range of pipe sizes that may be selected during design calculations. To access the Pipe Class Editor tab. Pipe Class Editor Pipe Class Editor allows you to edit the allowable schedules for each nominal diameter, for both Carbon Steel and Stainless Steel s. It also allows you to restrict the range of pipe sizes that may be selected during design calculations. Pipe Class Editor, click Pipe Class in Tools, on the 39 allows you to edit the allowable schedules for each Stainless Steel, during sizing s. It also allows you to restrict the range of pipe sizes that may be , on the Home 40 4 Pipe Network Fig 4.10 Note: If you have selected Use Pipe Class in the Preference Editor, these are the schedules which will be used. 5 Nodes 41 5 Nodes This section provides information on the following topics: - Overview - Node Manager - Ignoring/Restoring Nodes - Connection Nodes - Boundary Nodes Overview Pipes are connected via nodes, which can be added, edited and deleted from the Node Manager. Sources are also added through the Node Manager. Node Manager To access the Node Manager: Click Nodes in Build, on the Home tab. 42 Fig 5.1 The following buttons are available: Button Description Add You will be prompted to select the type of node. This new node will be named with a number depending upon the number of nodes of that type already added. Edit Allows you to edit the currently highlighted node. The form varies, depending Delete Allows you to remove the currently highlighted node. Close Closes the Ignoring/Restoring Nodes When you ignore a single node, all upstream nodes are automatically ignored. You can ignore sin single node, all upstream nodes are automatically ignored. This enables you to do what if type calculations, where part of the network can be excluded from the calculation without the need for delet appropriate nodes. To ignore a node 1 Open the node editor 2 On the Connections figure shows this for a connector node The following buttons are available: Description You will be prompted to select the type of node. This new node will be named with a number depending upon the number of nodes of that type already added. Allows you to edit the currently highlighted node. The form varies, depending on the type of node, as discussed below. Allows you to remove the currently highlighted node. Closes the Node Manager. Ignoring/Restoring Nodes When you ignore a single node, all upstream nodes are automatically ignored. You can ignore single or multiple nodes within the model. When you ignore a single node, all upstream nodes are automatically ignored. This enables you type calculations, where part of the network can be excluded from the calculation without the need for deletion and reinstallation of the appropriate nodes. To ignore a node: Open the node editor of the node that you want to ignore. Connections tab, select the Ignore check box. The fo figure shows this for a connector node. 5 Nodes You will be prompted to select the type of node. This new node will be named with a number depending upon the number of nodes of that Allows you to edit the currently highlighted node. The form varies, Ignoring/Restoring Nodes When you ignore a single node, all upstream nodes are automatically ignored. gle or multiple nodes within the model. When you ignore a single node, all upstream nodes are automatically ignored. This enables you type calculations, where part of the network can be excluded ion and reinstallation of the box. The following 5 Nodes 43 Fig 5.2 To restore a node that has previously been ignored: 1 Open the node editor of the node that you want to restore. 2 On the Connections tab, clear the Ignore check box. Connection Nodes The following types of connection nodes are available in Aspen Flare System Analyzer. A connection node is one that links two or more pipe segments. - Connector - Flow Bleed - Horizontal Separator - Orifice Plate - Tee - Vertical Separator Connector The Connector is used to model the connection of two pipes. The diameters of the pipes may be different. 44 Connections Tab The name of the connector and connectivity information is Fig 5.3 The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available Field Description Name The alphanumeric description of the 1). Location You may want to specify the location of the node in the plant. Upstream/ Downstream Either type in the name of the pipe segment or select At You can specify the end of the pipe segment attached to the connector. Ignore Select the calculations. Clear the check Calculations Tab Calculation methods are spec Connections Tab The name of the connector and connectivity information is specified here. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Description The alphanumeric description of the Connector (e.g. 1). You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select You can specify the end of the pipe segment attached to the connector. Select the Ignore check box to ignore this connector in the calculations. Clear the check box to re-enable it. Calculations Tab Calculation methods are specified here. 5 Nodes specified here. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different (e.g. - HP Connect You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the box to ignore this connector in the 5 Nodes Fig 5.4 The following fields are available on this tab: Field Description Angle Specify the connector expansion angle. If not defined, it will be calculated Length Enter the connector length. If not defined, it will be calcula Angle Fitting Loss Method The available options are: Isothermal Pressure Drop If this option is set to change calculations in the connector will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is flash will be used to update the inlet properties. The connector will do one size change calculation between the inlet and outlet diameters selecting expansion or contraction as appropriate. Setting this option to at cost of a minor loss of accuracy. Two Phase Correction If this option is set to flow will be calculated using properties corrected for liquid slip. If set to calculating the pressure loss coefficient. The following fields are available on this tab: Description Specify the connector expansion angle. If not defined, it will be calculated from Length. Enter the connector length. If not defined, it will be calcula Angle. The available options are: - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Calculated – Pressure drop is calculated in accordance with the Swage method. If this option is set to Yes, the inlet temperatures used for the size change calculations in the connector will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The connector will do one size change calculation between the inlet and outlet diameters selecting expansion or contraction as appropriate. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogenous properties of the fluid will be used in calculating the pressure loss coefficient. 45 Specify the connector expansion angle. If not defined, it will be Enter the connector length. If not defined, it will be calculated from Pressure drop calculation is ignored Pressure drop is calculated in accordance with , the inlet temperatures used for the size change calculations in the connector will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update a more rigorous PH The connector will do one size change calculation between the inlet and outlet diameters selecting expansion or contraction as ed up calculations in some cases the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set enous properties of the fluid will be used in 46 5 Nodes Field Description Swage Method The following options are available: - Compressible - pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. Summary Tab The result of the calculations at each of the pipe connections is displayed. 5 Nodes Fig 5.5 Flow Bleed The Flow Bleed is a simple calculation block that allows you to; - Specify a fixed pressure drop - Specify a constrained flow offtake wh from the following equation Offtake = Multiplier x Inlet Flow + Offset The calculated Offtake is constrained to maximum and minimum values. Connections Tab The name of the flow bleed and connectivity information is speci Flow Bleed The Flow Bleed is a simple calculation block that allows you to; Specify a fixed pressure drop. Specify a constrained flow offtake where the flow offtake is calculated from the following equation: Offtake = Multiplier x Inlet Flow + Offset The calculated Offtake is constrained to maximum and minimum values. Connections Tab The name of the flow bleed and connectivity information is speci 47 The Flow Bleed is a simple calculation block that allows you to; ere the flow offtake is calculated The calculated Offtake is constrained to maximum and minimum values. The name of the flow bleed and connectivity information is specified here. 48 Fig 5.6 The following fields are available on this tab: Field Description Name The alphanumeric description of the XX). Location You may want to specify the location of the Upstream/ Downstream Either type in the name of the pipe segment or select from the list. At You can specify the end of the pipe segment attached to the b Ignore Select the calculations. Clear the check Calculations Tab Calculation methods are specified here. The following fields are available on this tab: Description The alphanumeric description of the Flow Bleed (e.g. XX). You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the bleed. Select the Ignore check box to ignore this flow bleed in the calculations. Clear the check box to re-enable it. Calculations Tab Calculation methods are specified here. 5 Nodes (e.g. - HP Connect in the plant. Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the flow box to ignore this flow bleed in the 5 Nodes Fig 5.7 The following fields are available on this tab: Field Offtake Multiplier Offtake Offset Offtake Minimum Offtake Maximum Pressure Drop Summary Tab The result of the calculations at each of the pipe connections is displayed. The following fields are available on this tab: Description Specify the Offtake multiplier. The default value is 0. Specify the Offset for the Offtake to compensate for the changes in the inlet flow. Specify the minimum value for the Offtake. Specify the maximum value for the Offtake. Enter the pressure drop across the Flow Bleed. ry Tab The result of the calculations at each of the pipe connections is displayed. 49 Specify the Offtake multiplier. The default value is 0. et for the Offtake to compensate for the changes The result of the calculations at each of the pipe connections is displayed. 50 Fig 5.8 Horizontal Separator Horizontal separators are used to allow liquid to separate from the feed stream so that it can be removed from the flare system. The liquid phase in the horizontal separator System Analyzer, the secondary inlet/outlet, and one vapor outl Connections Tab The name of the horizontal separator and connectivity information is specified here. Horizontal Separator eparators are used to allow liquid to separate from the feed m so that it can be removed from the flare system. The liquid phase in eparator feed is removed from the network. In Aspen Flare System Analyzer, the Horizontal Separator has one primary inlet, one secondary inlet/outlet, and one vapor outlet stream. Connections Tab The name of the horizontal separator and connectivity information is specified 5 Nodes eparators are used to allow liquid to separate from the feed m so that it can be removed from the flare system. The liquid phase in feed is removed from the network. In Aspen Flare has one primary inlet, one The name of the horizontal separator and connectivity information is specified 5 Nodes Fig 5.9 You only need to provide 2 of 3 connections to be able to solve the separator. This allows for solution(s) to partially built network The following fields are available on this tab: Field Name Location (Primary /Secondary) Inlet/Outlet At Ignore Calculations Tab Calculation methods are specified here. You only need to provide 2 of 3 connections to be able to solve the separator. This allows for solution(s) to partially built networks. The following fields are available on this tab: Description The alphanumeric description of the Horizontal Separator (e.g. - HP KO Drum). You may want to specify the location of the node The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. Either type in the name of the pipe segment or select list. You can specify the end of the pipe segment attached to the horizontal separator. Select the Ignore check box to ignore this horizontal separator in the calculations. Clear the check box to re-enable it. Calculations Tab tion methods are specified here. 51 You only need to provide 2 of 3 connections to be able to solve the separator. Horizontal Separator node in the plant. hanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more Either type in the name of the pipe segment or select from the You can specify the end of the pipe segment attached to the box to ignore this horizontal separator enable it. 52 Fig 5.10 The following fields are available on this tab: Field Dimensions Group Diameter Liquid Level Methods Group Fitting Loss Method The following fields are available on this tab: Description Dimensions Group The internal diameter of the vessel. The liquid level in the vessel. Pressure drop is calculated based upon the vapor space above the liquid. The available options are; - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Calculated_Ignore Vena Contracta – Pressure drop is calculated in accordance with the Swage ignores the loss due vena contracta. - Calculated – Pressure drop is calculated in accordance with the Swage method including the loss due vena contracta. 5 Nodes The liquid level in the vessel. Pressure drop is calculated based Pressure drop calculation is ignored Pressure drop is method but Pressure drop is calculated in accordance with method including the loss due vena contracta. 5 Nodes 53 Field Description Isothermal Pressure Drop If this option is set to Yes, the inlet temperatures used for the size change calculations in the separator will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The horizontal separator does three size change calculations, one between each stream connection and the vessel body. Normally these will be expansion calculations for the primary and secondary inlets and a contraction calculation for the vapor outlet but they will automatically change if flows are reversed. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Size Change Group Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogenous properties of the fluid will be used in calculating the pressure loss coefficient. Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. 54 Field Body Dimension Composition Tab If the inlet feed flashes in the separator and as a result of mixture is converted into liquid fully and This can cause instability in the pressure solution of the whole network. To avoid this, Aspen Flare System Analyzer very small vapor fraction for the vapor outlet (<0.001%). composition of the vapor phase here. Fig 5.11 Description If this option is set to Full Body Area, the calculation for the primary inlet/vessel and secondary inlet/vessel size change wi use the whole vessel area. If Partial Body Area on Flow selected, the vessel area is reduced in proportion to the appropriate flow, i.e. if the secondary inlet volumetric flow is 20% of the total volumetric flow in the tee then 20% of the body area will be used in the size change calculation. The use of the Body Area on Flow option has the effect of increasing the pressure loss calculated by simple fixed K factors. Composition Tab If the inlet feed flashes in the separator and as a result of the flash, the is converted into liquid fully and the vapor outlet will have no flow. instability in the pressure solution of the whole network. To Aspen Flare System Analyzer creates an arbitrary vapor phase with all vapor fraction for the vapor outlet (<0.001%). You composition of the vapor phase here. 5 Nodes the calculation for the primary inlet/vessel and secondary inlet/vessel size change will Partial Body Area on Flow is the vessel area is reduced in proportion to the i.e. if the secondary inlet volumetric flow is 20% of the total volumetric flow in the tee then 20% of the body area ill be used in the size change calculation. The use of the Partial option has the effect of increasing the pressure loss calculated by simple fixed K factors. the flash, the the vapor outlet will have no flow. instability in the pressure solution of the whole network. To creates an arbitrary vapor phase with can specify the 5 Nodes Design Tab Fig 5.12 Field Min Drop Diameter Drain Volume Maximum Holdup time Design Length Settling Velocity Summary Tab The result of the calculations at each of the pipe connections is displayed. Design Tab Description Min Drop Diameter Enter the diameter of the minimum drop size to be removed. Enter the drain volume. Maximum Holdup time Enter maximum holdup time before the horizontal separator will be drained. Minimum length of the horizontal separator required to satisfy design conditions. Settling velocity of the minimum drop size to be removed. Summary Tab The result of the calculations at each of the pipe connections is displayed. 55 Enter the diameter of the minimum drop size to be Enter maximum holdup time before the horizontal ength of the horizontal separator required to minimum drop size to be removed. The result of the calculations at each of the pipe connections is displayed. 56 Fig 5.13 Orifice Plate An Orifice Plate perpendicular to the flat upstream face of the plate placed crossways in the pipe. Orifice plates are generally used to restrict the flow downstream of a blow down valve or restrict the flow from a high pressure section of a flare system to a low pressure section. They may also be used to allow flow measurement. Connections Tab The name of the orifice plate and connectivity information is specified here. Orifice Plate Orifice Plate is a thin plate, which has a clean-cut hole with straight walls perpendicular to the flat upstream face of the plate placed crossways in the pipe. Orifice plates are generally used to restrict the flow downstream of a blow down valve or restrict the flow from a high pressure section of a flare ystem to a low pressure section. They may also be used to allow flow Connections Tab The name of the orifice plate and connectivity information is specified here. 5 Nodes ole with straight walls perpendicular to the flat upstream face of the plate placed crossways in the pipe. Orifice plates are generally used to restrict the flow downstream of a blow down valve or restrict the flow from a high pressure section of a flare ystem to a low pressure section. They may also be used to allow flow The name of the orifice plate and connectivity information is specified here. 5 Nodes Fig 5.14 The following fields are available on this tab: Field Name Location Upstream/Downstream At Ignore Calculations Tab Calculation methods are specified here. The following fields are available on this tab: Description The alphanumeric description of the Orifice Plate HP OP). You may want to specify the location of the plant. Upstream/Downstream Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the orifice plate. Select the Ignore check box to ignore this orifice the calculations. Clear the check box to re- Calculations Tab Calculation methods are specified here. 57 Orifice Plate (e.g. - You may want to specify the location of the node in the Either type in the name of the pipe segment or select from e end of the pipe segment attached to box to ignore this orifice plate in -enable it. 58 Fig 5.15 Note: You only need to provide 1 of 3 sizing parameters. For Example, if you entered the Diameter Upstream Diameter Ratio The following fields are available on this tab: Field Description Dimensions Group Diameter Upstream Diameter Ratio Downstream Diameter Ratio Methods Group Fitting Loss Method The following options ou only need to provide 1 of 3 sizing parameters. For Example, if you Diameter, Aspen Flare System Analyzer will then Upstream Diameter Ratio and the Downstream Diameter Ratio The following fields are available on this tab: Description Dimensions Group The diameter of the orifice hole. The ratio of the throat diameter to the upstream pipe diameter. The ratio of the throat diameter to the downstream pipe diameter The following options are available: - Ignored - If this option is selected, the fitting losses for the orifice plate would not be calculated. Static pressure is balanced. - Thin Orifice - The fitting losses for the orifice plate will be calculated using the equations for the thin orifice plate. - Contraction/Expansion - For this method, orifice plates will be modeled as a sudden contraction from the inlet line size to the diameter of the hole followed by a sudden expansion the diameter of the hole to the outlet line size. 5 Nodes ou only need to provide 1 of 3 sizing parameters. For Example, if you then calculate the Downstream Diameter Ratio. ratio of the throat diameter to the upstream pipe diameter. he ratio of the throat diameter to the downstream pipe diameter. If this option is selected, the fitting losses for the orifice plate would not be calculated. Static pressure is ice plate will be calculated using the equations for the thin orifice plate. For this method, orifice plates will be modeled as a sudden contraction from the inlet line size to the diameter of the hole followed by a sudden expansion from the diameter of the hole to the outlet line size. 5 Nodes 59 Field Description Isothermal Pressure Drop If this option is set to Yes, the inlet temperatures used for the size change calculations in the orifice plate will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The orifice plate will do one contraction calculation and one expansion calculation if the Fitting Loss Method is set to Contraction/Expansion. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Size Change Group Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogeneous properties of the fluid will be used in calculating the pressure loss coefficient. Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations. The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. 60 Summary Tab Fig 5.16 The result of the calculations at each of the pipe connections is displayed. Tee The Tee is used to model the connection of three pipes pipes may be different. Connections Tab The name of the tee and connectivity information is specified here. Summary Tab The result of the calculations at each of the pipe connections is displayed. is used to model the connection of three pipes. The diameters of the pipes may be different. Connections Tab The name of the tee and connectivity information is specified here. 5 Nodes The result of the calculations at each of the pipe connections is displayed. . The diameters of the The name of the tee and connectivity information is specified here. 5 Nodes Fig 5.17 You only need to provide 2 of 3 connections to be able to solve the tee. This allows for solution(s) to partially The following fields are available on this tab: Field Name Location Upstream/Downstream/Branch At Ignore Calculations Tab Calculation methods are specified here. You only need to provide 2 of 3 connections to be able to solve the tee. This allows for solution(s) to partially built networks. The following fields are available on this tab: Description The alphanumeric description of the Tee 1). You may want to specify the location of the node in the plant. The location can have an alphanumer name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. Upstream/Downstream/Branch Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached with the tee. Select the Ignore check box to ignore this tee in the calculations. Clear the check box to re Calculations Tab Calculation methods are specified here. 61 You only need to provide 2 of 3 connections to be able to solve the tee. This The alphanumeric description of the Tee (e.g. - HP You may want to specify the location of the node in the plant. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. Either type in the name of the pipe segment or select You can specify the end of the pipe segment attached box to ignore this tee in the box to re-enable it. 62 Fig 5.18 The following fields are available on this tab: Field Description Dimensions Group Theta Specify the tee. Body Specify the diameter of the body of the tee. Methods Group e following fields are available on this tab: Description Dimensions Group Specify the angle of the branch to the upstream connection tee. Specify the diameter of the body of the tee. Allowable choices are: - Run - The diameter will be that of the inlet pipe. - Tail - The diameter will be that of the outlet pipe. - Branch - The diameter will be that of the branch pipe. - Auto - Set the body diameter to be larger of the inlet and branch pipe diameters. 5 Nodes connection of the Allowable choices are: ill be that of the inlet pipe. he diameter will be that of the outlet pipe. he diameter will be that of the branch pipe. the body diameter to be larger of the inlet and 5 Nodes 63 Field Description Fitting Loss Method The available options are: - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Simple - This method uses a constant, flow ration independent K factor for the loss through the branch and run. - Miller - This method uses a K factor which is interpolated using Miller Curves, which are functions of the flow and area ratios of the branch to the total flow as well as the branch angle. Loss coefficients at low values of the branch are to body area are extrapolated from the data presented on the charts. - Miller (Area Ratio Limited) – This method uses a K factor which is interpolated using Miller Curves, which are functions of the flow and area ratios of the branch to the total flow as well as the branch angle. The ratio of the branch area to body area is constrained by the lower limit presented on the charts. - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Gardel – This method calculates the K factor using the analytical equations of Gardel. Miller Chart Extrapolation The available options are: - None – No extrapolation is used. If the data falls outside the Miller chart, a fixed value of K (K=8.0) is used. - Miller Area Ratio Squared – Uses a K factor which is extrapolated using Miller Curves, assuming that the K factors are functions of the flow and area ratio squared, of the branch to the total flow as well as the branch angle. - Gardel – Uses the Gardel method to calculate K factor if the K factor is out of bounds in miller chart. Connector If Incomplete If this option is set to Yes, Aspen Flare System Analyzer will treat the Tee as a straight connector, ignoring the effect of the branch on pressure drop. The Tee will do three size change calculations between inlet/body, branch/body and body/outlet selecting expansion or contraction calculations as appropriate. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Isothermal Pressure Drop If this option is set to Yes, the inlet temperatures used for the size change calculations in the tee will not update during iterative calculations for pressure loss, i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. Swage Method Group Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogenous properties of the fluid will be used in calculating the pressure loss coefficient. 64 5 Nodes Field Description Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the tee at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the tee at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the tee at all times. Loss coefficients are calculated using HTFS correlations. The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. Body Dimension If this option is set to Full Body Area, the calculation for the inlet/body and branch/body size change will use the whole body area. If Partial Body Area on Flow is selected, the body area is reduced in proportion to the appropriate flow, i.e. if the branch volumetric flow is 20% of the total volumetric flow in the tee then 20% of the body area will be used in the size change calculation. This option is ignored if the fittings loss method is set to Miller. The use of the Partial Body Area on Flow option has the effect of increasing the pressure loss calculated by simple fixed K factors bringing the results closer to those calculated by the ore accurate Miller K factors. Summary Tab The result of the calculations at each of the pipe connections is displayed. 5 Nodes Fig 5.19 Vertical Separator Vertical separators are used to allow liquid to separate from the feed stream so that it can be removed from the flare system. The liquid phase in the vertical separator feed is removed from the network. In Aspen Flare System Analyzer, the Vertical Separator stream. Connections Tab The name of the vertical separator and connectivity information is specified here. Vertical Separator eparators are used to allow liquid to separate from the feed stream so that it can be removed from the flare system. The liquid phase in the eparator feed is removed from the network. In Aspen Flare System Vertical Separator has only one inlet and one vapor outlet Connections Tab The name of the vertical separator and connectivity information is specified 65 eparators are used to allow liquid to separate from the feed stream so that it can be removed from the flare system. The liquid phase in the eparator feed is removed from the network. In Aspen Flare System has only one inlet and one vapor outlet The name of the vertical separator and connectivity information is specified 66 Fig 5.20 The location can have an alphanumeric name. This feature is useful for flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Field Description Name The alphanumeric description of the Drum). Location You may want to specify the location of the Inlet/Outlet Either type in the name of the pipe segment or select from the list. At You can specify the end of the pipe segment attached to the separato Ignore Select the calculations. Clear the check Calculations Tab Calculation methods are specified here. The location can have an alphanumeric name. This feature is useful for flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Description The alphanumeric description of the Vertical Separator Drum). You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the eparator. Select the Ignore check box to ignore this vertical separator in the calculations. Clear the check box to re-enable it. Calculations Tab Calculation methods are specified here. 5 Nodes The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different Vertical Separator (e.g. - HP KO in the plant. Either type in the name of the pipe segment or select from the list. You can specify the end of the pipe segment attached to the vertical box to ignore this vertical separator in the 5 Nodes Fig 5.21 The following fields are available on this tab: Field D Diameter The internal diameter of the vessel. Methods Group Fitting Loss Method The available options are: Isothermal Pressure Drop If this optio change calculations in the separator will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to flash will be used to update the inlet properties. The vertical separator will do one expansion calculation for the inlet stream entering the vessel and one contraction calculation for the flow from the vessel to the outlet. These will automatic flows through the vessel are reversed. Setting this option to at cost of a minor loss of accuracy. Size Change Group The following fields are available on this tab: Description The internal diameter of the vessel. The available options are: - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Calculated Ignore Vena Contracta – Pressure drop is calculated in accordance with the Swage method but ignores the loss due vena contracta. - Calculated – Pressure drop is calculated in accordance with the Swage method including the loss due vena contracta. If this option is set to Yes, the inlet temperatures used for the size change calculations in the separator will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more r flash will be used to update the inlet properties. The vertical separator will do one expansion calculation for the inlet stream entering the vessel and one contraction calculation for the flow from the vessel to the outlet. These will automatic flows through the vessel are reversed. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Size Change Group 67 Pressure drop calculation is ignored sure drop is method but Pressure drop is calculated in accordance with method including the loss due vena contracta. , the inlet temperatures used for the size change calculations in the separator will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update a more rigorous PH The vertical separator will do one expansion calculation for the inlet stream entering the vessel and one contraction calculation for the flow from the vessel to the outlet. These will automatically change if can speed up calculations in some cases 68 5 Nodes Field Description Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogenous properties of the fluid will be used in calculating the pressure loss coefficient. Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations. The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. Composition Tab If the inlet feed flashes in the separator, as a result of the flash, the mixture is converted into liquid fully and the vapor outlet will have no flow. This can cause instability in the pressure solution of the whole network. To avoid this, Aspen Flare System Analyzer creates an arbitrary vapor phase with very small vapor fraction for the vapor outlet (<0.001%). You can specify the composition of the vapor phase here. 5 Nodes Fig 5.22 69 70 Design Tab Fig 5.23 Field Min Drop Diameter Design Diameter Settling Velocity Summary Tab The result of the calculations at each of the pipe connections is displayed. Design Tab Description Min Drop Diameter Enter the diameter of the minimum drop size to be removed. Minimum diameter of the vertical separator required to satisfy design conditions. Settling velocity of the minimum drop size to be removed. Summary Tab The result of the calculations at each of the pipe connections is displayed. 5 Nodes Enter the diameter of the minimum drop size to be Minimum diameter of the vertical separator required to elocity of the minimum drop size to be removed. The result of the calculations at each of the pipe connections is displayed. 5 Nodes Fig 5.24 Boundary Nodes The following types of boundary nodes are available in Aspen Flare System Analyzer. A bounda - Control Valve - Relief Valve - Flare Tip The relief valve and control valve node types represent sources or inflows into the system. The alternative types of sources purge valves. Control Valve The Control Valve valves, bursting disks and blow down valves. The most significant difference to the Relief Valve Connections Tab The name of the control valve and connectivity information is specified here. Boundary Nodes The following types of boundary nodes are available in Aspen Flare System Analyzer. A boundary node is one that is connected to only one pipe segment. Control Valve Relief Valve The relief valve and control valve node types represent sources or inflows into the system. The Control Valve, in particular, may also be used to model ive types of sources, such as blow down valves, rupture disks, and Control Valve Control Valve is used to model a constant flow source, such as purge ting disks and blow down valves. The most significant difference Relief Valve is that the rated flow equals the nominal flow. Connections Tab The name of the control valve and connectivity information is specified here. 71 The following types of boundary nodes are available in Aspen Flare System ry node is one that is connected to only one pipe segment. The relief valve and control valve node types represent sources or inflows into , in particular, may also be used to model rupture disks, and such as purge ting disks and blow down valves. The most significant difference is that the rated flow equals the nominal flow. The name of the control valve and connectivity information is specified here. 72 Fig 5.25 The location can h flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Field Description Name The al Location You may want to specify the location of the Outlet Either type in the name of the pipe segment or select from the list. At You can specify where the pipe segment is valve. Ignore Select the calculations. Clear the check Conditions Tab Fluid conditions are specified here. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Description The alphanumeric description of the Control Valve (e.g. You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from the list. You can specify where the pipe segment is to be attached to the alve. Select the Ignore check box to ignore this control valve in the calculations. Clear the check box to re-enable it. Conditions Tab Fluid conditions are specified here. 5 Nodes ave an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different (e.g. - FCV 1). in the plant. Either type in the name of the pipe segment or select from the list. to be attached to the control box to ignore this control valve in the 5 Nodes Fig 5.26 It is recommended that a value to an isenthalpic flash from the upstream conditions down to the Back Pressure. This will give the highest probable entry temperature into the system which will in turn give the highest velocities. The following fields are available on this tab: Field Description Conditions Group Inlet Pressure Inlet Temp. Spec. It is recommended that a value for Outlet Temperature which corresponds to an isenthalpic flash from the upstream conditions down to the . This will give the highest probable entry temperature into the system which will in turn give the highest velocities. lowing fields are available on this tab: Description Conditions Group The pressure of the source on the upstream side of the valve. The temperature specification of the source on the ups of the control valve. You can select the fluid condition from the list on the left side. The available options are: - Actual - The given inlet temperature is the actual fluid temperature. - Superheat - If this option is selected, enter the amount of superheat. - Subcool - If this option is selected, enter the amount of subcooling. 73 which corresponds to an isenthalpic flash from the upstream conditions down to the Allowable . This will give the highest probable entry temperature into The pressure of the source on the upstream side of the valve. The temperature specification of the source on the upstream side You can select the fluid condition from the list The given inlet temperature is the actual fluid If this option is selected, enter the amount of s option is selected, enter the amount of 74 5 Nodes Field Description Allowable Back Pressure The Allowed Back Pressure is the pressure that is allowed to exist at the outlet of a pressure relief device as a result of the pressure in the discharge system. It is the sum of the superimposed and built-up back pressure. Clicking Set calculates the Allowable Back Pressure as a function of the Inlet Pressure. Selecting the Auto check box will automatically calculate the Allowable Back Pressure whenever the Inlet Pressure changes. Outlet Temperature This is the temperature of the source at the flange on the downstream side of the valve. If the enthalpy method chosen is the Ideal Gas model, this temperature is used to determine the enthalpy of the source at the entrance to the pipe network; otherwise, this enthalpy is calculated from the upstream pressure and temperature. If Set was clicked, and the enthalpy model is Peng Robinson, Soave Redlich Kwong or Lee Kesler, the outlet temperature will be calculated from the upstream temperature and pressure after isenthalpic expansion to the defined Allowable Back Pressure. Mass Flow This is the mass flow of the source. This is generally the flow rate generated by the upset condition. Dimensions Group Flange Diameter This is the diameter of the flange at the valve discharge. The flange diameter may be left unknown in which case it will be assumed to be the same as the outlet pipe. Composition Tab The fluid composition is specified here. 5 Nodes Fig 5.27 The following fields are available on Field Description Basis T Mole Fraction Mol. Wt. The the composition basis selected is If the composition basis selected is Fraction change the component fractions. Fluid Type If to calculate a binary weight. If the two components of the specified fluid type are not found Component Fractions The fluid composition in either mole or mass fractions. You can only enter data here if fractions. You can normalize the composition either manually editing the component fractions or by clicking If the composition component fractions are estima weight. The following fields are available on this tab: Description The composition basis, which may be either Molecular Mole Fraction or Mass Fraction. The molecular weight of the fluid. You can only enter data here if the composition basis selected is molecular weight. If the composition basis selected is Mole Fraction Fraction, the molecular weight is updated when you enter or change the component fractions. If molecular weight is selected , you need to select the to calculate a binary composition in order to match the molecular weight. If the two components of the specified fluid type are not found, the other components are used. The fluid composition in either mole or mass fractions. You can only enter data here if the composition basis selected is mole or mass fractions. You can normalize the composition either manually editing the component fractions or by clicking Normalise. If the composition Basis selected is molecular weight, the component fractions are estimated when you change the molecular weight. 75 ecular Weight, molecular weight of the fluid. You can only enter data here if . or Mass , the molecular weight is updated when you enter or you need to select the Fluid Type composition in order to match the molecular weight. If the two components of the specified fluid type are not The fluid composition in either mole or mass fractions. You can only the composition basis selected is mole or mass fractions. You can normalize the composition either manually editing selected is molecular weight, the ted when you change the molecular 76 Field Description Clone Composition From This button allows the copying of compositional data from another control Normalise Normalises the composition such that the sum of the component fractions is 1. Methods Tab Calculation methods are specified here. Fig 5.28 The following fields are available on this tab: Fields Description Description This button allows the copying of compositional data from another control valve in the same scenario. Normalises the composition such that the sum of the component fractions is 1. Methods Tab Calculation methods are specified here. The following fields are available on this tab: Description 5 Nodes This button allows the copying of compositional data from another Normalises the composition such that the sum of the component 5 Nodes 77 Fields Description VLE Method The options for the Vapor-Liquid Equilibrium calculations are as follows (see Chapter 9 Theoretical Basis): - Compressible Gas – Real Gas relationship. This is only available when the Enthalpy Method on the Calculation Options Editor is Ideal Gas. - Peng Robinson – Peng Robinson Equation of State. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Soave Redlich Kwong – Soave Redlich Kwong Equation of State. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Vapour Pressure – Vapour Pressure method as described in API Technical Data Book– Volume 113. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Model Default - If this is selected, the Default method for the VLE method (as defined on the Calculation Options Editor) will be used. Swage Group Fitting Loss Method The available options are; - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Calculated – Pressure drop is calculated in accordance with the Swage method. Isothermal Pressure Drop If this option is set to Yes, the inlet temperatures used for the size change calculations in the control valve will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The control valve will do one size change calculation from the defined flange diameter to the outlet pipe diameter. This will normally be an expansion. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogeneous properties of the fluid will be used in calculating the pressure loss coefficient. 78 5 Nodes Fields Description Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations. The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. Estimated Properties at Header Conditions Group Vapour Fraction The initial estimates for the flow profile in looped systems are generated based on the assumption of vapor phase flow without any liquid knockout in the system. It is not uncommon for sources to pass through a knockout drum before connection to the main header. Specification of an estimate of vapor fraction of the fluid at the knockout drum can considerably enhance the automatically generated flow profile. If not specified, for the initial estimates, the fluid is assumed to be vapor only at the header condition. Vapour Mol. Wt. Specify the estimated vapor molecular weight for the vapor fraction given above. If provided, this value is used to assist the automatic generation of the flow profile for looped systems. If not specified, for the initial estimates, the vapour molecular weight is assumed to be the same as the overall fluid molecular weight at the header condition. Inlet Piping Tab Details of the piping between the protected equipment and the inlet to the control valve are specified here. This data is used to calculate the pressure drop in the inlet piping. The diameter of the inlet piping is also used to calculate the inlet velocity of the source fluid when the Include Kinetic Energy option is selected in the Calculation Options Editor. 5 Nodes Fig 5.29 The available fields are: Fields Description Routing Group Length The length of the inlet piping. Elevation Change The change in elevation of the inlet piping. Th than the length of the piping. Properties Group Material The material of the inlet pipe Steel Roughness The surface roughness of the inlet pipe. Whenever a material is selected, the absolute roughn the material as defined on the Diameter Group Nominal Diameter The nominal pipe diameter used to describe the inlet pipe size. For pipes with a nominal diameter of 14 inches or more, this wi same as the outside diameter of the pipe. Schedule If a pipe schedule is selected, you will be able to select a nominal pipe diameter from the pipe databases. It will not be necessary to specify the internal diameter. The available fields are: Description The length of the inlet piping. The change in elevation of the inlet piping. This cannot be greater than the length of the piping. Properties Group The material of the inlet pipe, either Carbon Steel or Steel. The surface roughness of the inlet pipe. Whenever a material is selected, the absolute roughness is initialized to the default value for the material as defined on the Preferences Editor. Diameter Group The nominal pipe diameter used to describe the inlet pipe size. For pipes with a nominal diameter of 14 inches or more, this wi same as the outside diameter of the pipe. If a pipe schedule is selected, you will be able to select a nominal pipe diameter from the pipe databases. It will not be necessary to specify the internal diameter. 79 is cannot be greater or Stainless The surface roughness of the inlet pipe. Whenever a material is ess is initialized to the default value for The nominal pipe diameter used to describe the inlet pipe size. For pipes with a nominal diameter of 14 inches or more, this will be the If a pipe schedule is selected, you will be able to select a nominal pipe diameter from the pipe databases. It will not be necessary to specify 80 Fields Description Internal Diameter The pipe Use Pipe Class Select defined by the Fittings Groups Loss Coefficient Enter the A and B parameters for the following fitt equation in which F flow: K = A + Summary Tab The result of the calculations is displayed. Fig 5.30 Description The pipe diameter used for the pressure drop calculations. Select Yes to restrict the sizes of the inlet piping selected to those defined by the Pipe Class tool. Enter the A and B parameters for the following fittings K factor equation in which Ft is the friction factor for fully developed turbulent flow: K = A + BF t Summary Tab The result of the calculations is displayed. 5 Nodes diameter used for the pressure drop calculations. to restrict the sizes of the inlet piping selected to those ings K factor is the friction factor for fully developed turbulent 5 Nodes Relief Valve The Relief Valve source can be used to model types of spring loaded relief valves. Relief valves are used frequently in many industries in order to prevent dangerous situations occurring from pressure build Connections Tab The name of the relief valve and connectivity information is specified here. Fig 5.31 The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it ief Valve source can be used to model types of spring loaded relief valves. Relief valves are used frequently in many industries in order to prevent dangerous situations occurring from pressure build-ups in a system. Connections Tab ame of the relief valve and connectivity information is specified here. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. 81 source can be used to model types of spring loaded relief valves. Relief valves are used frequently in many industries in order to ups in a system. ame of the relief valve and connectivity information is specified here. The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different 82 5 Nodes The following fields are available on this tab: Field Description Name The alphanumeric description of the Relief Valve (e.g. - FCV 1). Location You may want to specify the location of the node in the plant. Outlet Either type in the name of the pipe segment or select from the list. At You can specify where the pipe segment is to be attached to the relief valve. Ignore Select the Ignore check box to ignore this relief valve in the calculations. Clear the check box to re-enable it. Conditions Tab Fluid conditions are specified here. 5 Nodes Fig 5.32 It is recommended that a value for to an isenthalpic flash from the upstream conditions down to the Back Pressure. This will give the highest the system which will in turn give the highest velocities. The following fields are available on this tab: Field Conditions Group MAWP It is recommended that a value for Outlet Temperature which corresponds to an isenthalpic flash from the upstream conditions down to the . This will give the highest probable entry temperature into the system which will in turn give the highest velocities. The following fields are available on this tab: Description Conditions Group The Maximum Allowable Working Pressure (MAWP maximum gauge pressure permissible in a vessel at its operating temperature. It is normally equal to the relief valve set pressure unless you have a low pressure vessel. 83 which corresponds to an isenthalpic flash from the upstream conditions down to the Allowable probable entry temperature into MAWP) is the e permissible in a vessel at its operating temperature. It is normally equal to the relief valve set pressure 84 5 Nodes Field Description Contingency In general there are two types of process upset conditions: - Operating - The relieving pressure is 110% of MAWP unless you have a multiple valve assembly in which case it is 116% of MAWP. Some of the operating upset examples are cooling failure, power failure and instrument air failure. - Fire - The relieving pressure is 121% of MAWP. Relieving Pressure The Relieving Pressure is equal to the valve set pressure plus the overpressure. You can either enter the value or have it calculated using the MAWP and the Contingency by clicking Set. If you entered a value less than the MAWP, a warning message will be generated. Selection of the Auto check box will automatically calculated the relieving pressure from the MAWP and Contingency whenever these values change. Inlet Temp. Spec. The temperature specification of the source on the upstream side of the relief valve. You can select the fluid condition from the drop down box on the right hand side of this field. The available options are: - Actual - It uses the given inlet temperature as the actual fluid temperature. - Superheat - If this option is selected, enter the amount of superheat. - Subcool - If this option is selected, enter the amount of subcooling. Allowable Back Pressure The Allowable Back Pressure is the pressure that is allowed to exist at the outlet of a pressure relief device as a result of the pressure in the discharge system. It is the sum of the superimposed and built-up back pressure. Clicking Set calculates the Allowable Back Pressure as a function of the valve type and MAWP. If the Auto check box is selected then the allowed back pressure is automatically updated whenever the valve type or MAWP is changed. Outlet Temperature This is the temperature of the source on the downstream side of the valve. If the enthalpy method chosen is the Ideal Gas model, then this temperature is used to determine the enthalpy of the source at the entrance to the pipe network, otherwise this enthalpy is calculated by isenthalpic flash from the upstream pressure and temperature. If Set is pressed and the enthalpy model is Peng Robinson, Soave Redlich Kwong or Lee Kesler, the outlet temperature will be calculated from the upstream temperature and pressure after expansion to the defined Allowable Back Pressure. Mass Flow The nominal mass flow of the source. This is generally the flowrate generated by the upset condition. Rated Flow It is the rated mass flow of the source. This is generally the flowrate that the relief valve is capable of passing. Clicking Set calculates the rated flow from the MAWP, valve type, orifice area, valve count, upstream pressure, upstream temperature and sizing method. If the Auto check box is selected, the rated flow will be automatically updated after any change in these values. Rated Flow Parameters 5 Nodes 85 Field Description K(Cp/Cp-R) K is the Ideal Gas ratio of specific heats. Compressibility Compressibility Factor for the deviation of the actual gas from a perfect gas evaluated at inlet conditions. (Z= PV/MRT) Valve Design Group Flange Diameter The diameter of the valve discharge flange. The flange diameter may be left unknown in which case it will be assumed to be the same as the outlet pipe. Number of Valves Specify the number of valves for the source. Orifice Area Per Valve The orifice area per valve may be set by selecting the orifice size code from the list. The corresponding orifice area will then be displayed. If the size code is set to the blank entry, the orifice area per valve may be entered manually. Valve Type The choices are: - Balanced - A spring loaded pressure relief valve that incorporates a means for minimizing the effect of back pressure on the performance characteristics. - Conventional - A spring loaded pressure relief valve whose performance characteristics are directly affected by changes in the back pressure on the valve. - Pilot - A pilot-operated pressure relief valve in which the pilot is a self-actuated device. The major relieving device is combined with and is controlled by the pilot. Mech. BP Limit The maximum mechanical back pressure that can be applied to the valve. Composition Tab The fluid composition is specified here. 86 Fig 5.33 The following fields are available on this tab: Field Description Basis The composition basis, which may be either Fraction Mol. Wt. The molecular weight of the fluid. You can only enter data here if the compositi If the composition basis selected is the molecular weight is updated when you enter or change the component fractions. Fluid Type If Molecular Weight is selected in the composition bas select the match the molecular weight. If the two components of the specified fluid type are not found e following fields are available on this tab: Description The composition basis, which may be either Molecular Fraction or Mass Fraction. he molecular weight of the fluid. You can only enter data here if the composition basis selected is Molecular Weight. If the composition basis selected is Mole Fraction or the molecular weight is updated when you enter or change the component fractions. If Molecular Weight is selected in the composition bas select the Fluid Type to calculate a binary composition in order to match the molecular weight. If the two components of the specified fluid type are not found, the other components are used. 5 Nodes ecular Weight, Mole he molecular weight of the fluid. You can only enter data here if the or Mass Fraction, the molecular weight is updated when you enter or change the If Molecular Weight is selected in the composition basis list, you need to to calculate a binary composition in order to match the molecular weight. If the two components of the specified fluid 5 Nodes 87 Field Description Component Fractions The fluid composition in either mole or mass fractions. You can only enter data here if the composition basis selected is mole or mass Fraction. You can normalize the composition by either manually editing the component fractions or by clicking Normalise. If the composition basis selected is Molecular Weight, the component fractions are estimated when you change the molecular weight. Clone Composition From This button allows the copying of compositional data from another relief valve in the same scenario. Normalise Normalises the composition such that the sum of the component fractions is 1. Methods Tab Calculation methods are specified here. 88 Fig 5.34 The following fields are available on this tab: Field The following fields are available on this tab: Description 5 Nodes 5 Nodes 89 Field Description VLE Method The options for the Vapor-Liquid Equilibrium calculations are as follows (see Chapter 9 Theoretical Basis): - Compressible Gas – Real Gas relationship. This is only available when the Enthalpy Method on the Calculation Options Editor is Ideal Gas. - Peng Robinson – Peng Robinson Equation of State. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Soave Redlich Kwong – Soave Redlich Kwong Equation of State. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Vapour Pressure – Vapour Pressure method as described in API Technical Data Book– Volume 113. This is only available when the Enthalpy Method on the Calculation Options Editor is NOT Ideal Gas. - Model Default - If this is selected, the Default method for the VLE method (as defined on the Calculation Options Editor) will be used. Swage Group Fitting Loss Method The available options are; - Equal Static Pressure – Pressure drop calculation is ignored and static pressure is balanced. - Calculated – Pressure drop is calculated in accordance with the Swage method. Isothermal Pressure Drop If this option is set to Yes, the inlet temperatures used for the size change calculations in the relief valve will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The relief valve will do one size change calculation from the defined flange diameter to the outlet pipe diameter. This will normally be an expansion. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. Two Phase Correction If this option is set to Yes, the pressure loss coefficient in two phase flow will be calculated using properties corrected for liquid slip. If set to No, the homogeneous properties of the fluid will be used in calculating the pressure loss coefficient. 90 5 Nodes Field Description Method The following options are available: - Compressible - Pressure losses will be calculated assuming compressible flow through the connector at all times. - Incompressible (Crane) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using Crane coefficients. - Transition - Pressure losses will be calculated initially using the assumption of incompressible flow. If the pressure loss expressed as a percentage of the inlet pressure is greater than the defined compressible transition value then the pressure drop will be recalculated using the compressible flow method. - Incompressible (HTFS) - Pressure losses will be calculated assuming incompressible flow through the connector at all times. Loss coefficients are calculated using HTFS correlations. The Incompressible method calculations are faster but will be less accurate at higher pressure drops. The Transition method can cause instabilities in some cases if the calculated pressure drop is close to the transition value. - Balance Total Pressure – Frictional pressure drop is ignored and total pressure is balanced between upstream & downstream. Compressible Transition This entry defines the pressure drop as a percentage of the inlet pressure at which compressible flow pressure drop calculations should be used. It applies only when the Transition method is selected. Sizing Method Group Sizing Method The four sizing method options available are: - API (1976) – American Petroleum Institute method in the 1976 edition of RP 520 pt 1. No account is made of liquid flashing as it passes through the relief valve, thus this method is not recommended for either two phase or flashing fluids. - API (1993) – American Petroleum Institute method in the 1993 edition of RP 520 pt 1. Liquid flashing is handled by a simplified approach in which the fluid is flashed to the outlet pressure. The relative quantities of each phase at the outlet condition are then used at the inlet of the valve to determine the two phase capacity - API(2000) – American Petroleum Institute method in the 2000 edition of RP 520 pt 1. This method is often referred to as the Diers or Leung method. This is the recommended method for all two phase fluids. - HEM – Homogeneous Equilibrium method. Back Pressure Back pressure to be used for rating the relief valve. If this value is not specified, the Allowable Back Pressure is used. MultiPhase Cd Discharge coefficient to be used of relief valve in multiphase service. Liquid Cd Discharge coefficient to be used for relief valves in liquid service. 5 Nodes 91 Field Description Kb User defined back pressure correction factor. If this field is left blank, the back pressure correction factor is calculated. This value should only be specified in exceptional cases. Energy Balance Group Isentropic Flash Select Yes to use an isentropic flash between the inlet and outlet otherwise an isenthalpic flash will be done. Isentropic Efficiency Fractional isentropic efficiency for the isentropic flash. Estimated Properties at Header Conditions Group Vapour Fraction The initial estimates for the flow profile in looped systems are generated based on the assumption of vapor phase flow without any liquid knockout in the system. It is not uncommon for sources to pass through a knockout drum before connection to the main header. Specification of an estimate of vapor fraction of the fluid at the knockout drum can considerably enhance the automatically generated flow profile. If provided, this value is used to assist the automatic generation of the flow profile for looped systems. If not specified, for the initial estimates, the fluid is assumed to be vapour only at the header condition. Vapour Mol. Wt. Specify the estimated vapor molecular weight for the vapor fraction given above. If provided, this value is used to assist the automatic generation of the flow profile for looped systems. If not specified, for the initial estimates, the vapour molecular weight is assumed to be the same as the overall fluid molecular weight at the header condition. Inlet Piping Tab Details of the piping between the protected equipment and the inlet to the relief valve are specified here. This data is used to calculate the pressure drop in the inlet piping to ensure that it does not exceed the recommended limit of 3% of the inlet pressure. The diameter of the inlet piping is also used to calculate the inlet velocity of the source fluid when the Include Kinetic Energy option is selected in the Calculation Options Editor. 92 Fig 5.35 The available fields are: Field Description Routing Group Length The length of the Elevation Change The change in elevation of the inlet piping. T than the Properties Group Material The material of the inlet pipe Steel Roughness The surface selected, the absolute roughness is initialized to the default value for the material as defined on the Diameter Group The available fields are: Description The length of the inlet piping. The change in elevation of the inlet piping. This cannot be greater than the Length of the piping. Properties Group The material of the inlet pipe, either Carbon Steel or Steel. The surface roughness of the inlet pipe. Whenever a material is selected, the absolute roughness is initialized to the default value for the material as defined on the Preferences Editor. Diameter Group 5 Nodes his cannot be greater or Stainless roughness of the inlet pipe. Whenever a material is selected, the absolute roughness is initialized to the default value for 5 Nodes 93 Field Description Nominal Diameter The nominal pipe diameter used to describe the inlet pipe size. For pipes with a nominal diameter of 14 inches or more, this will be the same as the outside diameter of the pipe. Schedule If a pipe schedule is selected, you will be able to select a nominal pipe diameter from the pipe databases. It will not be necessary to specify the internal diameter. Internal Diameter The pipe diameter used for the pressure drop calculations. Use Pipe Class Select Yes to restrict the sizes of the inlet piping selected to those defined by the Pipe Class tool. Fittings Groups Loss Coefficient Enter the A and B parameters for the following fittings K factor equation in which Ft is the friction factor for fully developed turbulent flow: K = A + BFt Summary Tab The result of the calculations is displayed. 94 Fig 5.36 Source Tools The initial sizing of a flare system is time consuming both in terms of time taken to build the model and the computation time. Using an method can speed up the calculation during the initial Speed is an important issue during sizing calculations especially for a complex multiple scenario case. Typically, the back pressure should be used for calculations. Rigorous rating calculation for all scenarios can be done by the Peng Robinson pressure dependency and provides the Source Tools The initial sizing of a flare system is time consuming both in terms of time taken to build the model and the computation time. Using an Ideal Gas method can speed up the calculation during the initial sizing estimation. Speed is an important issue during sizing calculations especially for a complex multiple scenario case. Typically, the back pressure should be used for calculations. Rigorous rating calculation for all scenarios can be done by the enthalpy method or any other enthalpy methods with pressure dependency and provides the downstream temperature. 5 Nodes The initial sizing of a flare system is time consuming both in terms of time Ideal Gas sizing estimation. Speed is an important issue during sizing calculations especially for a complex multiple scenario case. Typically, the back pressure should be used for calculations. Rigorous rating calculation for all scenarios can be done by the enthalpy method or any other enthalpy methods with temperature. 5 Nodes 95 Updating Downstream Temperatures The downstream temperatures are only used to define the system entry temperature when ideal gas enthalpies are used. After several cycles of rating and sizing calculations, the original values for each source may no longer be valid. These values may be updated to reflect the results of the last calculation using an equation of state enthalpy method as follows: Click Source Tools in Tools on the Home tab; select Refresh Source Temperatures from the list. Adding Single Source Scenarios The thorough evaluation of a flare network will require the evaluation of many scenarios. In most systems, there will be the possibility of each relief valve lifting on its own. In the case of a petrochemical complex, this could have several hundred relief valves and the task of setting up the scenarios for each relief valve would be time consuming and error prone. Once all the major scenarios have been defined, select Add Single Source Scenarios from Source Tools. Click Yes to allow Aspen Flare System Analyzer to analyze the existing scenarios to determine the greatest flow rate for each relief valve and create a scenario using this data. Flare Tip The Flare Tip is used to model outflows from the system. It can model either ignited combustible gas flare tips or open vents. Nonphysical equipment such as a connection to a fixed pressure exit at a plant boundary can also be modeled. Connections Tab The name of the flare tip and connectivity information is specified here. 96 Fig 5.37 The location can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Field Name Location Upstream node At Ignore Calculations Tab Calculation methods are specified here. n can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different sections to make it more comprehensible. The following fields are available on this tab: Description The alphanumeric description of the Flare Tip (e.g. Tip). You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from list. You can specify the end of the pipe segment attached to the flare tip. Select the Ignore check box to ignore this flare tip in the calculations. Clear the check box to re-enable it. Calculations Tab Calculation methods are specified here. 5 Nodes n can have an alphanumeric name. This feature is useful for large flowsheets, because you can provide a different “location” name to different (e.g. - HP Flare You may want to specify the location of the node in the plant. Either type in the name of the pipe segment or select from list. e pipe segment attached to the flare box to ignore this flare tip in the 5 Nodes Fig 5.38 The following fields are a Field Diameter Methods Group Use Curves Fitting Loss Coefficient Fittings Loss Coefficient Basis Isothermal Pressure Drop The following fields are available on this tab: Description You can specify a diameter for the tip. If this value is not specified then the diameter of the connected pipe is used. Select this check box if you are supplying pressure drop c calculate the pressure drop of the flare tip. Data for these curves is entered on the Curves tab. The fitting loss coefficient will be used to calculate the pressure drop through the flare tip. Select whether the supplied Fittings Loss Coefficient calculate the total pressure loss including velocity pressure loss or static pressure loss only. If this option is set to Yes, the inlet temperatures used for the size change calculations in the flare tip will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to rigorous PH flash will be used to update the inlet prope The flare tip will do a one size calculation for the change in diameter between inlet pipe and the flare tip. Setting this option to Yes can speed up calculations in some cases at cost of a minor loss of accuracy. 97 You can specify a diameter for the tip. If this value is not specified then the diameter of the connected pipe is used. box if you are supplying pressure drop curves to calculate the pressure drop of the flare tip. Data for these curves The fitting loss coefficient will be used to calculate the pressure Fittings Loss Coefficient will locity pressure loss , the inlet temperatures used for the ze change calculations in the flare tip will not update during iterative calculations for pressure loss i.e. a PT flash will be used to update the inlet properties. If the option is set to No, a more rigorous PH flash will be used to update the inlet properties. The flare tip will do a one size calculation for the change in can speed up calculations in some 98 Curves Tab User specified pressur used if the Use Curves Fig 5.39 The following fields are available on this tab: Field Ref. Temp. Pressure Correction Mol. Wt. Extrapolation Flow Extrapolation Curves Tab User specified pressure drop curves are specified here. These will only be Use Curves field on the Calculation tab is unchecked. The following fields are available on this tab: Description Enter the reference temperature to which the pr curves correspond. All curves must be for the same reference temperature. If checked, the static pressure correction takes into account density differences due to both the calculated inlet pressure and calculated inlet pressure. The temperature correction is automatically applied, but this box must be checked in order for pressure effects to be modeled. This box should normally be checked. If this is selected, extrapolation beyond the range of supplie molecular weight curves is performed if necessary; otherwise, the bounding molecular weight curve is used. If this is selected, extrapolation beyond the range of supplied mass flow rates is performed if necessary; otherwise, the bounding mass flow is used. 5 Nodes e drop curves are specified here. These will only be ab is unchecked. Enter the reference temperature to which the pressure drop curves correspond. All curves must be for the same reference the static pressure correction takes into account density differences due to both the calculated inlet pressure and sure. The temperature correction is but this box must be checked in order for pressure effects to be modeled. This box should normally be If this is selected, extrapolation beyond the range of supplied molecular weight curves is performed if necessary; otherwise, If this is selected, extrapolation beyond the range of supplied mass flow rates is performed if necessary; otherwise, the 5 Nodes Field Mol. Wt. Mass Flow/Pres. Drop Summary Tab The result of the calculation is displayed. Fig 5.40 Description Enter the molecular weight at which the pressure drop curve applies. Add Mol. Wt. can be used to add additional curves. The list can then be used to select which pressure drop curve is displayed. Delete Mol. Wt. will delete the selected pressure drop curve. These pairs of data define points in the pressure drop curve. Points may be added and removed from the curve by using Point and Delete Point. Pressure drops for flows between those in the table are calculated using linear interpolation. Summary Tab The result of the calculation is displayed. 99 Enter the molecular weight at which the pressure drop curve can be used to add additional curves. The list can then be used to select which pressure drop curve is the selected pressure drop These pairs of data define points in the pressure drop curve. Points may be added and removed from the curve by using Add . Pressure drops for flows between those re calculated using linear interpolation. 100 5 Nodes 6 Calculations 6 Calculations This section provides information on the following topics: - Starting the Calculations - Efficient Modeling Techniques Starting the Ca The following words before the object on the status bar show the type of calculation being performed - B = Mass and Energy Calculations - P = Pressure Drop Calculations To start the calculations, select the Ribbon. The status of the rating calculations is shown on the Status Bar the left corner of the Status Bar shows the status of the current case. The second display fiel iteration number, then the maximum pressure error for that iteration and finally the name of the pipe segment responsible for the error. The third display field shows firstly the number of iterati and then the error in the objective function being solved by the loop solver. The right corner of the Status Bar shows the the percentage zoom setting to quickly zoom in or zoom out when viewing t Process Flowsheet. Fig 6.1 To abort calculations Note: Due to speed considerations, it is recommended that sizing calculations be performed subject to the constraints: Enthalpy Method, or 6 Calculations This section provides information on the following topics: Starting the Calculations Efficient Modeling Techniques Starting the Calculations The following words before the object on the status bar show the type of calculation being performed: B = Mass and Energy Calculations P = Pressure Drop Calculations To start the calculations, select Run from the Run group, on the The status of the rating calculations is shown on the Status Bar the left corner of the Status Bar shows the status of the current case. The second display field on the Status Bar shows firstly the inner properties loop iteration number, then the maximum pressure error for that iteration and finally the name of the pipe segment responsible for the error. The third display field shows firstly the number of iterations taken by the loop solver, and then the error in the objective function being solved by the loop solver. The right corner of the Status Bar shows the Zoom Slider. You can slide to the percentage zoom setting to quickly zoom in or zoom out when viewing t Process Flowsheet. To abort calculations, click Stop, which activates during calculations. Due to speed considerations, it is recommended that sizing calculations be performed subject to the constraints: Compressible Gas VLE , or no Heat Transfer Calculations. 101 The following words before the object on the status bar show the type of the Home tab of The status of the rating calculations is shown on the Status Bar. The icon on the left corner of the Status Bar shows the status of the current case. The d on the Status Bar shows firstly the inner properties loop iteration number, then the maximum pressure error for that iteration and finally the name of the pipe segment responsible for the error. The third ons taken by the loop solver, and then the error in the objective function being solved by the loop solver. . You can slide to the percentage zoom setting to quickly zoom in or zoom out when viewing the during calculations. Due to speed considerations, it is recommended that sizing calculations VLE, Ideal Gas 102 6 Calculations Efficient Modeling Techniques Efficient modeling of a flare network requires some forethought in order to meet the primary objectives which are in general: 1 Definition of the design constraints for the flare system. These are usually defined by company standards or by local health and safety regulations. If unavailable, standard texts such as API-RP-521 can be used to select preliminary acceptable values. 2 Efficient acquisition of the data for the piping configuration and layout. 3 Definition of the scenarios or contingencies which should be evaluated. Grass roots design will require analysis of a far wider range of scenarios to those required by the simple expansion of a flare system to incorporate a new relief valve. 4 Rapid construction of the computer model of the flare system. 5 Fast and efficient calculation of the computer model of the flare system. Objectives 1 to 3 can only be achieved by the use of engineering skill and judgment. Once complete, the efficient use of Aspen Flare System Analyzer can lead to a satisfactory project conclusion. Data Entry Aspen Flare System Analyzer has a wide range of methods for entering the data for each object within the model. In general, you should use the method that you are most comfortable with, but experience has shown that use of the Process Flowsheet environment for definition of the piping configuration and layout can save many man days of labor with large flare networks. Although there is no set order in which the model must be built, the recommended sequence of data entry for building the model is: 1 Define the project description, user name, etc. by selecting Description from the Application Menu which is displayed after clicking the aspenONE Button on the upper left corner of the application window. 2 Set preferences for the default piping materials, type of Tee, composition basis, etc. from the Preferences Editor, accessed via the Application Menu. These may be overwritten on an object by object basis at any stage. Ensure that the Edit Objects On Add check box is selected if you want to edit the object data as each new flowsheet object is created. 3 Define a pipe class if appropriate. This will ensure that you only use pipe sizes as allowed by your project. Open the Pipe Class Editor in the Tools group on the Home tab of the Ribbon. 4 With the Calculation Options Editor, define default calculation methods for VLE, Pressure Drop, etc. To open this view, click Options in the Run group on the Home tab. 5 Define all the source nodes (relief valves and control valves) for the first scenario. The first scenario should be the one that has the greatest level of common data amongst the complete set of scenarios. The recommended method of creation is to drag the nodes from the Palette to the Process Flowsheet. 6 Calculations 103 6 Define the design constraints on Mach number, noise, etc. for the first scenario using the Scenario Manager. To access this dialog box, in the Build group on the Home tab, click Scenarios. 7 Define the pipe network (common to all scenarios). If the network is to be sized, some care must be taken in defining reasonable estimates for the pipe diameters. 8 Add the next scenario by clicking Add on the Scenario Manager. The data for the sources should be cloned from the previously defined scenario that has the most similar data. Edit the design constraints of this scenario if necessary. 9 Make the new scenario current. Highlight it on the Scenario Manager and click Current. 10 Edit the source data for each source for the new scenario. Double-click sources on the Process Flowsheet. 11 Repeat steps 8 through 10 for all scenarios. Calculation Speed Calculation time will often be only a small percentage of the time taken to construct the computer model. However, on low specification personal computers, a sizing calculation for a complex multiple scenario model could take several hours, if not days, when care is not taken in the selection of the thermodynamic models or in the definition of the component slate. When considering the desired accuracy for the calculations, due consideration must be given to the fact that you are modeling a system that will rarely come close to a steady state condition, with a steady state modeling tool. Component Slate As a rule of thumb you can assume that the calculation time is proportional to the square of the number of components. This is especially true when the VLE is calculated by an equation of state instead of treating the fluids as a simple compressible gas. Flare systems generally operate at conditions in which heavy components such as hexane or heavier will stay in the liquid phase throughout the system. You should therefore endeavor to characterize the heavy ends of petroleum fluids by as few components as possible. The properties that you use for the characterization should be optimized to: - Ensure the component stays in the liquid phase. - Match the liquid phase density. VLE Method Source compositions may be modeled either by definition of a molecular weight or by a detailed component by component analysis. When a composition is defined solely by molecular weight, Aspen Flare System Analyzer analyzes the user defined component slate to select a pair of components whose molecular weights straddle the defined value. A binary composition is then calculated to match this value. This type of fluid characterization is only suitable for network analyses in which the fluids are 104 6 Calculations assumed to be vapor, since the VLE behavior cannot be reasonably predicted from this level of detail. Thus the Compressible Gas VLE method is the only one that should ever be used in association with molecular weight modeling. When modeling using a detailed component by component analysis, if you are confident that the system will be liquid free, then the Compressible Gas VLE method should be used since it does not have the overhead of determining the vapor/liquid equilibrium split. The computation time for the fluid properties then becomes several orders of magnitudes faster that those involving a liquid phase. When modeling a system in which two phase effects are important, consideration must be given to the pressures both upstream of the sources and within the flare piping. The Vapor Pressure VLE method, which is the fastest of the multiphase methods, is, strictly speaking, only valid for pressures below 10 bar. The reduced temperature of the fluid should also be greater than 0.3. Experience has shown that it also works to an acceptable degree of accuracy for flare system analysis at pressures well beyond this. If speed is an issue, it is recommended that a scenario with as many active sources as possible be rated both using one of the cubic equations of state and this method. If acceptable agreement between the results is achieved, it may be reasonably assumed that the extrapolation is valid. Sizing Calculations The final calculations upon which a flare system is built should of course be made using the most detailed model consistent with the quality of data available, but for initial sizing calculations, a number of points should be considered when selecting appropriate calculation methods. - There is not generally a great deal of difference between the pressure drops calculated for a two phase system, whether calculated by treating the system as a compressible gas or as a two phase fluid. This occurs since the fluid condenses the velocities will decrease while the two-phase friction factor will increase. - Unless choked flow is allowed in the system, the back pressure on each source should not vary greatly with line size. The specification of a reasonable fixed downstream temperature for each source to be used with the ideal gas enthalpy model should therefore give reasonable results. The recommended procedure for performing sizing calculations is as follows: 1 Build the network using reasonable estimates for the pipe diameters. Estimate the diameters from: PM W d 300 = d = Diameter (m) W = Mass flow (kg/s) P = Tip pressure (bar abs) M = Design mach number 6 Calculations 105 2 Rate the network for all the scenarios with your desired detailed model for the VLE and enthalpies. This will give reasonable temperatures downstream of each source. 3 Copy the calculated temperatures downstream of each source to the source data by selecting Refresh Source Temperatures from Source Tools in the Tools group on the Home tab of the Ribbon. 4 Size the network for all scenarios using Compress Gas VLE and Ideal Gas enthalpies. 5 Rate the network for all the scenarios with your desired detailed model for the VLE and enthalpies. If there are any design violations, make a debottlenecking calculation with these methods. 106 6 Calculations 7 Databases 107 7 Databases This section provides information on the following topics: - Overview - Database Features - Setting the Password - Pipe Schedule Database Editor - Fittings Database Editor - Component Database Editor Overview The data for the various installable components of the model are stored in user-modifiable database files. The database files are: - PIPE_SCHEDULE.MDB - The pipe schedule database. This contains data for both carbon steel and stainless steel pipe. - FITTINGS.MDB - The pipe fittings database. - COMPONENTS.MDB - The pure component database. These files are initially installed to the Database sub-directory in your Aspen Flare System Analyzer working directory. Note: You may add and edit your own data to the databases. However, you cannot edit or delete any of the original data. The databases may be password protected by a single password common to each. If the password has been disabled, or an incorrect access password has been entered, the databases may be reviewed in read-only mode. You must have defined an access password before any database can be edited. Note: Original data is always read-only. 108 7 Databases Database Features The Navigation Pane and tabbed environment provide a new user friendly way to navigate and view simultaneously multiple results and input views. Input and Results open in a tabbed environment like Microsoft Internet Explorer. All the windows are dockable allowing you to organize and customize the workspace. Grid Controls The data view is supported with rich grid controls for all input and result views. The grid controls permit you to sort, custom filter on every column field. With filtering, you can restrict the data and choose to view only those that want to see. To access the filters in the data grid, click the filter icon in the column header to display a list in which you can choose from. You may use the following pre-defined auto filters: - Blanks - NonBlanks - Above Average - Below Average - Top 10 - Top 10 percentile - Bottom 10 - Bottom 10 percentile If you need to add a custom filter, select Custom from the list. The Custom Filter Selection window is displayed. You need to add and edit the Operator and Operand in the table, then group them with logical conjunction and disjunction to setup a custom filter. The following buttons are available: Button Description Add Condition Add a condition in the table. You need to choose a proper Operator, and then input a value for the Operand to complete the new condition. Remove Condition (s) Remove one or more previously added conditions. Press Ctrl to select multiple rows in the table. Group Selected 'And' Group Group the selected conditions and perform the logical AND operation for the group. Multiple conditions need to be selected before this button is activated. 'Or' Group Group the selected conditions and perform the logical OR operation for the group. Multiple conditions need to be selected before this button is activated. Toggle Toggle the selected logical groups between the logical operations AND and OR. 7 Databases Button Ungroup A logical formula is displayed under the table to conditions added. Click Maneuvering Through the Table Click the table to select a record, and then navigate through the the navigator and scroll bar controls. Fig 7.1 Printing Click Print All to print the pipe schedule, fittings or component data, depending on which editor you are currently using. Aspen Flare System Analyzer prints format Adding/Deleting Data When Add is clicked, the last record on the table. You should data. 1. When you add items, they will then become immediately available to the simulation. 2. Click Delete Description Upgroup the selected conditions. A logical formula is displayed under the table to show the relation for all the conditions added. Click OK to apply the custom filter. Maneuvering Through the Table Click the table to select a record, and then navigate through the the navigator and scroll bar controls. to print the pipe schedule, fittings or component data, depending on which editor you are currently using. Aspen Flare System Analyzer prints formatted output using the default printer settings. Adding/Deleting Data is clicked, a new record that contains dummy data is inserted as the last record on the table. You should override this data with your actual When you add items, they will then become immediately available to the to delete the current record. 109 show the relation for all the Click the table to select a record, and then navigate through the table using to print the pipe schedule, fittings or component data, depending on which editor you are currently using. Aspen Flare System ted output using the default printer settings. a new record that contains dummy data is inserted as override this data with your actual When you add items, they will then become immediately available to the 110 Note: You can only delete your own data. 3. Click OK to confirm Setting The Password To set or modify the password: Select Set Password clicking the aspenONE button on the upper left corner of the application window. The Password Editor Fig 7.2 If you have already set your password, you first need to enter the existing password before supplying the new one. 1. Enter your existing password in the 2. Enter your new password in both the Password boxes, Pipe Schedule Database Editor The Pipe Schedule Database Editor data for all pipes in the database, and to add and edit user 1 To use the Pipe Schedule Database Editor Database Editor you enter the password, t be displayed. You can only delete your own data. confirm the update for database. Setting The Password To set or modify the password: Set Password from the Application Menu that can be opened by clicking the aspenONE button on the upper left corner of the application ord Editor window will now be displayed. If you have already set your password, you first need to enter the existing password before supplying the new one. Enter your existing password in the Old Password box. Enter your new password in both the New Password and boxes, and then click OK. Click Cancel to abort the procedure. Pipe Schedule Database Editor Pipe Schedule Database Editor allows you to view the pipe schedule s in the database, and to add and edit user-defined entries. Pipe Schedule Database Editor, select Pipe Schedule Database Editor from the Databases tab on the Navigation Pane you enter the password, the Pipe Schedule Database Editor 7 Databases that can be opened by clicking the aspenONE button on the upper left corner of the application If you have already set your password, you first need to enter the existing and Confirm New to abort the procedure. Pipe Schedule Database Editor allows you to view the pipe schedule defined entries. Pipe Schedule n the Navigation Pane. After Pipe Schedule Database Editor view will 7 Databases Fig 7.3 2 If you have already set your password, you will need to enter the password before accessing the databases. 3 Select the mat either Carbon The Nominal Diameter and Group for each entry are tabulated. The database can be modified by either adding or de Add or Delete, respectively. Click printer defined in the Page Setup in the For information on the Database view fea Schedule, Fittings and Components Databases, see If you have already set your password, you will need to enter the password before accessing the databases. Select the material you want to view from the Material list. This may be Carbon Steel or Stainless Steel. Diameter, Schedule, Internal Diameter, Wall Thickness for each entry are tabulated. The database can be modified by either adding or deleting the entries using , respectively. Click Print All to print the database to the printer defined in the Page Setup dialog box that can is opened in the Print Preview window. For information on the Database view features that are common to the Pipe Schedule, Fittings and Components Databases, see Database Features 111 If you have already set your password, you will need to enter the list. This may be Wall Thickness leting the entries using to print the database to the dialog box that can is opened from File | tures that are common to the Pipe Database Features. 112 Fittings Database Editor The Fittings Database Editor fittings types in the database, and to add and edit user To display the Fittings Database Editor from the Database password, the Fittings D Fig 7.4 The description of each fitting, as well as the A and B term in the pipe fitting equation is tabulated. The Reference defines the literature source for the data. The pipe fitting equation is: t BF A K + = For information on the Database view features that are common to the Pipe Schedule, Fittings and Components Databases, see Component Database Editor The Component Dat for all the pure components in the database, and to add and edit user entries. Fittings Database Editor Fittings Database Editor allows you to view the pipe fitt fittings types in the database, and to add and edit user-defined entries. Fittings Database Editor, select Fittings Database Editor Databases tab on the Navigation Pane. After you enter the Fittings Database Editor will be displayed. The description of each fitting, as well as the A and B term in the pipe fitting equation is tabulated. The Reference defines the literature source for the The pipe fitting equation is: For information on the Database view features that are common to the Pipe Schedule, Fittings and Components Databases, see Database Features Component Database Editor Component Database Editor allows you to view the component data for all the pure components in the database, and to add and edit user 7 Databases allows you to view the pipe fittings data for all defined entries. Database Editor . After you enter the The description of each fitting, as well as the A and B term in the pipe fitting equation is tabulated. The Reference defines the literature source for the For information on the Database view features that are common to the Pipe Database Features. Component Database Editor allows you to view the component data for all the pure components in the database, and to add and edit user-defined 7 Databases To display the Component Database Editor Database Editor enter the password, the Fig 7.5 The data for each component in the database is tabulated. For information on the Database view features that are common to the Pipe Schedule, Fittings and Componen Importing Component Data Additional components may be added to the database via an ASCII file whose format is given in Component Database Editor, select Component Database Editor from the Database tab on the Navigation Pa enter the password, the Component Database Editor will be displayed. The data for each component in the database is tabulated. For information on the Database view features that are common to the Pipe Schedule, Fittings and Components Databases, see Database Features Importing Component Data Additional components may be added to the database via an ASCII file whose format is given in Appendix A – File Format. 113 Components tab on the Navigation Pane. After you will be displayed. For information on the Database view features that are common to the Pipe Database Features. Additional components may be added to the database via an ASCII file whose 114 7 Databases 8 Automation 115 8 Automation This section provides information on the following topics: - Overview - Objects - Aspen Flare System Analyzer Object Reference - Example - Updating Automation Files From Previous Versions Overview Automation, defined in its simplest terms, is the ability to drive one application from another. For example, the developers of Product A have decided in their design phase that it would make their product more usable if they exposed Product A’s objects, thereby making it accessible to automation. Since Products B, C and D all have the ability to connect to the application that have exposed objects, each can programmatically interact with product A. The exposure of its objects makes Aspen Flare System Analyzer a very powerful and useful tool in the design of hybrid solutions. Since access to an application through Automation is language-independent, anyone who can write code in Visual Basic, C++ or Java, to name three languages, can write applications that will interact with Aspen Flare System Analyzer. There are a number of applications that can be used to access Aspen Flare System Analyzer through Automation, including Microsoft Visual Basic, Microsoft Excel and Visio. With so many combinations of applications that can transfer information, the possibilities are numerous and the potential for innovative solutions is endless. 116 8 Automation Objects The key to understanding Automation lies in the concept of objects. An object is a container that holds a set of related functions and variables. In Automation terminology, the functions of an object are called Methods and the variables are called Properties. Consider the example of a simple car. If it were an object, a car would have a set of properties such as; make, color, engine, etc. The car object might also have methods such as; drive, refuel, etc. By utilizing the properties and methods of the car object it is possible to define, manipulate and interact with the object. Fig 8.1 Each property of the car is a variable that has a value associated with it. The color could be either a string or a hexadecimal number associated with a specific color. The gas mileage could be a floating-point value. Methods are nothing more than the functions and subroutines associated with the object. An object is a container that holds all the attributes associated with it. An object can contain other objects that are a logical subset of the main object. The car object might contain other objects such as engine or tire. These objects have their own set of independent properties and methods. An engine can have properties related to the number of valves and the size of the pistons. The tires would have properties such as the tread type or model number. Object Hierarchy The path that is followed to get to a specific property may involve several objects. The path and structure of objects is referred to as the object hierarchy. In Visual Basic the properties and methods of an object are accessed by hooking together the appropriate objects through a dot operator (.) function. Each dot operator in the object hierarchy is a function call. In many cases it is beneficial to reduce the number of calls by setting intermediate object variables. For instance, expanding on our previous example involving the car, suppose there exists an object called Car and you wish to set the value of its engine size. You could approach the problem in one of two ways. Direct specification of object property Car.Engine.Size = 3 Indirect specification of object property 8 Automation 117 Dim Eng1 as Object Set Eng1 - Car.Engine.Size Eng1 = 3 If the Engine size is a property that you wish to access quite often in your code, using the indirect method of specification might be easier as it reduces the amount of code thereby reducing the possibility of error. The Aspen Flare System Analyzer Type Library In order to do anything with objects it is first necessary to know what objects are available. When an application is exposed to Automation, a separate file is usually created that lists all the objects and their respective properties and methods. This file is called the type library and nearly all programs that support Automation have one of these files available. With the help of an Object Browser, such as the one built into Microsoft Excel, you now have a way to view all the objects, properties, and methods in the application by examining the type library. For Aspen Flare System Analyzer, the type library is contained within the file AspenTech.FlareSystemAnalyzer.Interfaces.dll. The Aspen Flare System Analyzer type library reveals numerous objects that contain many combine properties and methods. The type library shows the associated properties and methods for every object, and returns type for every property. The type library shows what types of arguments are required and what type of value might be returned for every method. Accessing a specific property or method is accomplished in a hierarchical fashion by following a chain of exposed objects. The first object in the chain is an object from which all other objects can be accessed. This object will typically be the main application. In Aspen Flare System Analyzer, the starting object is the Application object. All other objects are accessible from this starting object. Object Browser The type library itself does not exist in a form that is immediately viewable to you. In order to view the type library, you require the use of an application commonly referred to as an Object Browser. The Object Browser will interpret the type library and display the relevant information. Microsoft Excel and Visual Basic both include a built in Object Browser. Accessing the Object Browser in Excel for V7.3 Onwards 1 Press <Left Alt><F11> or select Visual Basic Editor from Macro group in the Tools menu (For Excel 2007 or later, please select Visual Basic in the Code group on the Developer tab). 2 Within the Visual Basic Editor, choose References from the Tools menu. 3 Select the box next to AspenTech.FlareSystemAnalyzer.Interfaces. If this is not displayed, use Browse to locate AspenTech.FlareSystemAnalyzer.Interfaces.dll. 118 4 Click OK. 5 Choose Object Browser 6 Click the arrow in the box at the upper left of the window, and then s AspenTech.FlareSystemAnalyzer Example: Navigating through the type library This example shows how to navigate through t determine the object hierarchy necessary to access a particular property. The desired property is the mass flow of a relief valve called “PSV 1” in the currently active scenario. The first step is to start with the starting obje Flare System Analyzer is always the Fig 8.2 Selecting the Application properties and methods. Examination of the list of properties does not reveal a relief valve object so access to a particular relief valve must be through another object. The properties that are links to other objects can be determined by looking at the type shown when a property is selected. If the type is not String most likely an object. The object type shown will be found somewhere in the object list and the next step is to determine the object hierarchy. With prior experience in Aspen Flare System Analyzer, the object is a logical choice. Object Browser from the View menu or press <F2>. arrow in the box at the upper left of the window, and then s FlareSystemAnalyzer.Interfaces.dll from the list. Example: Navigating through the type library This example shows how to navigate through the type library in order to determine the object hierarchy necessary to access a particular property. The desired property is the mass flow of a relief valve called “PSV 1” in the currently active scenario. The first step is to start with the starting object that in the case of Aspen Flare System Analyzer is always the Application object. Application object in the browser reveals all of its related properties and methods. Examination of the list of properties does not reveal valve object so access to a particular relief valve must be through another object. The properties that are links to other objects can be determined by looking at the type shown when a property is selected. If the String, Boolean, Variant, Double, Integer or Long most likely an object. The object type shown will be found somewhere in the object list and the next step is to determine the object hierarchy. With prior experience in Aspen Flare System Analyzer, the ReliefValves a logical choice. 8 Automation <F2>. arrow in the box at the upper left of the window, and then select from the list. Example: Navigating through the type library he type library in order to determine the object hierarchy necessary to access a particular property. The desired property is the mass flow of a relief valve called “PSV 1” in the ct that in the case of Aspen object in the browser reveals all of its related properties and methods. Examination of the list of properties does not reveal valve object so access to a particular relief valve must be through another object. The properties that are links to other objects can be determined by looking at the type shown when a property is selected. If the Long then it is most likely an object. The object type shown will be found somewhere in the object list and the next step is to determine the object hierarchy. ReliefValves 8 Automation Fig 8.3 The ReliefValves simple object that is a collection of other objects with some properties and methods for navigation through the collection. Fig 8.4 The Item proper IReliefValve, The argument named “What” is of type Variant which is the default argument type for an argument unless otherwise specified. All collection objects within Aspen Flare System Analyzer allow access individual member of the collection either by index number (like an array) or ReliefValves object is shown to be of type IReliefValve. This object is a simple object that is a collection of other objects with some properties and methods for navigation through the collection. property is shown to return an indexed object of type , The argument named “What” is of type Variant which is the default argument type for an argument unless otherwise specified. All collection objects within Aspen Flare System Analyzer allow access individual member of the collection either by index number (like an array) or 119 . This object is a simple object that is a collection of other objects with some properties and ty is shown to return an indexed object of type , The argument named “What” is of type Variant which is the default argument type for an argument unless otherwise specified. All collection objects within Aspen Flare System Analyzer allow access to an individual member of the collection either by index number (like an array) or 120 directly by name. Named arguments are case insensitive so “PSV 1” is the same as “psv 1”. Either approach is equally valid. Examining the IReliefValve PropertyByName Fig 8.5 This property is a read/write property that is used to access all data for a relief valve. The argument is a case insensitive string that describes the variable that we wish to access. In th list of property names for each type of object is given at the end of this chapter. The resulting syntax to access the desired property is: ReliefValves.Item(“PSV1”).PropertyByName(“MassFlow”) Automation Syntax Declaring Objects An object in Visual Basic is another type of variable and should be declared. Objects can be declared using the generic type identifier preferred method however uses the type library reference to declare the object variables by an explicit object name. Early Binding: Dim | Public | Private library Late Binding: directly by name. Named arguments are case insensitive so “PSV 1” is the same as “psv 1”. Either approach is equally valid. IReliefValve object type shows a property called PropertyByName, which is type Variant. This property is a read/write property that is used to access all data for a The argument is a case insensitive string that describes the variable that we wish to access. In this case this string would have the valve “MassFlow”. A full list of property names for each type of object is given at the end of this The resulting syntax to access the desired property is: ReliefValves.Item(“PSV1”).PropertyByName(“MassFlow”) omation Syntax Declaring Objects An object in Visual Basic is another type of variable and should be declared. Objects can be declared using the generic type identifier object preferred method however uses the type library reference to declare the ect variables by an explicit object name. | Public | Private Objectvar as ObjectName as specified in the type 8 Automation directly by name. Named arguments are case insensitive so “PSV 1” is the property called This property is a read/write property that is used to access all data for a The argument is a case insensitive string that describes the variable that we is case this string would have the valve “MassFlow”. A full list of property names for each type of object is given at the end of this An object in Visual Basic is another type of variable and should be declared. object. The preferred method however uses the type library reference to declare the ObjectName as specified in the type 8 Automation 121 Dim | Public | Private objectvar as Object Once a reference to a type library has been established, the actual name of the object as it appears in the type library can be used. This is called early binding. It offers some advantages over late binding, including speed and access to Microsoft’s IntelliSense © functionality when using Visual Basic or VBA. Example: Object Declaration Early Binding: Public fnApp as Object Public thisPsv as Object Late Binding: Public fnApp as AspenTech.FlareSystemAnalyzer.Interfaces.Application Public thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve The Set Keyword Syntax: Set objectvar = object.[object...].object | Nothing Connections or references to object variables are made by using the Set keyword. Example: Set Assuming fnApp is set to the Application Object Dim thisPsv as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve Set thisPsv - fnApp.ReliefValves.item(1) CreateObject, GetObject Syntax for creating an instance of an application: CreateObject (class) GetObject ([pathname] [,class]) Where class is the starting object as specified in the type library. In order to begin communication between the client and server applications, an initial link to the server application must be established. In Aspen Flare System Analyzer this is accomplished through the starting object Application. The CreateObject function will start a new instance of the main application. CreateObject is used in Aspen Flare System Analyzer with the AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.Application class as defined in the type library. This connects to the main application interface of Aspen Flare System Analyzer. 122 8 Automation Example: CreateObject Dim FnApp As Object Set FnApp = CreateObject (“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer. Interfaces.Application”) The following example uses early binding in the object declaration to create an instance of Aspen Flare System Analyzer and then load a specified model. Example: CreateObject Dim FnApp As AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.Application Set FnApp = CreateObject (“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer. Interfaces.Application”) FnApp.OpenModel “c:\Aspen Flare System Analyzer <version>\Samples\Ole\Excel\olesample.fnw” The GetObject function will connect to an instance of the server application that is already running. If an instance of the application is not already running then a new instance will be started. Object Properties, Methods and Hierarchy Syntax for creating and accessing properties: Set objectvar = object.[object.object...] .object Variable = object.[object.object...] .object.property Syntax for accessing methods: Function Method returnvalue = object.method ([argument1, argument2, ...]) Subroutine method object.method argument1, argument2, ... The sequence of objects is set through a special dot function. Properties and methods for an object are also accesses through the dot function. It is preferable to keep the sequences of objects to a minimum since each dot function is a call to a link between the client and the server application. The object hierarchy is an important and fundamental concept for utilizing automation. A particular property can only be accessed by following a specific chain of objects. The chain always begins with the Application object and ends with the object containing the desired property. The methods of objects are accessed in the same fashion as properties by utilizing the dot function. A method for a particular object is nothing more than a function or subroutine whose behavior is related to the object in some fashion. 8 Automation 123 Typically the methods of an object will require arguments to be passed when the method is called. The type library will provide information about which arguments are necessary to call a particular method. A function will return a value. Note: Subroutines in Visual Basic do not require parentheses around the argument list. Examples: Accessing Aspen Flare System Analyzer Object Properties Dim FnApp As AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.Application Dim SepDiam as Double Set FnApp = CreateObject (“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer. Interfaces.Application”) FnApp.OpenModel “c:\Aspen Flare System Analyzer <version>\Samples\Ole\Excel\olesample.fnw” SepDiam - FnApp.HorizontalSeparators.Item[1].PropertyByName (“Diameter”) This example starts up Aspen Flare System Analyzer and opens a specific case. The diameter of a specific horizontal separator is then obtained. The diameter is obtained through a connection of the Application and HorizontalSeparators objects. Dim FnApp As AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.Application Dim Seps as AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.IHorizontalSeparators Dim Sep as AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer.In terfaces.IHorizontalSeparator Dim SepDiam as Double Set FnApp = CreateObject (“AspenTech.FlareSystemAnalyzer.InterfacesAspenTech.FlareSystemAnalyzer. Interfaces.Application”) FnApp.OpenModel “c:\Aspen Flare System Analyzer <version>\Samples\Ole\Excel\olesample.fnw” Set Seps = FnApp.HorizontalSeparators Set Sep = Seps.Item[I] SepDiam = Sep.PropertyByName (“Diameter”) 124 8 Automation This example also gets the diameter of a specific horizontal separator, but creates all the intermediate objects so that when the diameter value is actually requested the chain of objects only contains one object. Collection Objects Syntax: Properties of a Collection Object: - Item(Index) -- Accesses a particular member of the collection by name or number - Count -- Returns the number of objects in the collection Syntax: Enumeration of Objects: Dim Element as Object Dim iElement as Long Dim nElements as Long For iElement=1 to nElements Set Element = FnApp.Elements.Item(iElement) [statements] Next [element] A collection object is an object that contains a set of other objects. This is similar to an array of objects. The difference between an array of objects and a collection object is that a collection object is that a collection object contains a set of properties and methods for manipulating the objects in the collection. The Count property returns the number of items in the collection and the Item property takes an index value or name as the argument and returns a reference to the object within the collection. Examples: Accessing Collection Objects Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValves Dim name as String Dim i As Integer Set myPsvs = myApp.ReliefValves For i = 1 To myPsvs.Count name = myPsvs.Item(i).PropertyByName(“Name”) MsgBox name Next i This example connects to a collection of relief valves by setting the myPsvs object. A For loop is created that uses the Count and item properties of a collection in order to display a message box that display the name of each relief valve in turn. The items in the collection are indexed beginning at 1. The application object is assumed to have been already set to myApp. Variants Syntax: Using variant values: 8 Automation 125 Dim myvariant as Variant myvariant = [object.property] To determine the upper and lower bound of the variant: UBound(arrayname[,dimension]) LBound(arrayname[,dimension]) A property can return a variety of variable type. Values such as Temperature or Pressure are returned as Doubles or 32-bit floating point values. The Name property returns a String value. Visual Basic provides an additional variable called Variant. A Variant is a variable that can take on the form of any type of variable including Integer, Long, Double, String, Array, and Objects. If the property of an object returns an array whose size can vary depending upon the case, then a Variant is used to access that value. For example, the Composition property of a ControlValve returns an array of Doubles sized to the number of components in the model. In Visual Basic, if a variable is not explicitly declared then it is implicitly a Variant. Variants have considerably more storage associated with their use so for a large application it is good practice to limit the number of Variants being used. It is also just good programming practice to explicitly declare variables whenever possible. Example: Using Variants in Aspen Flare System Analyzer Dim myPsvs as AspenTech.FlareSystemAnalyzer.Interfaces.IReliefValve Dim molefracs as Variant Dim i As Integer Set myPsv = myApp.ReliefValves.Item(1) molefracs = myPsv.PropertyByName (“Composition”) For i = LBound(molefracs) To Ubound (molefracs) Debug.Print molefracs(i) Next i This example shows how to get the mole fractions of a relief valve for the current scenario. The values are sent to the Visual Basic Immediate window. The application object is assumed to have been already set to myApp. Unknown Values There are a number of occasions where a variable may be unknown such as all the calculated values prior to the calculation or the flange size of a control valve. In all cases this is represented by the value fntVariableStatus_fntUnknownValue. 126 8 Automation Example: Using Unknown Values in Aspen Flare System Analyzer Dim myValve as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValves Dim myValves as AspenTech.FlareSystemAnalyzer.Interfaces.IControlValve Dim flange as Double Dim name as String Set myValves = myApp.ControlValves For i=1 to myValves.Count flange = myValves.Item(i).PropertyByName (“FlangeDiameter”) If flange = fntVariableStatus_fntUnknownValue Then name = myValve.PropertyByName(“Name”) MsgBox name EndIf Next i This example loops through all the control valves and displays the name of any whose flange diameter is unknown. The application object is assumed to have been already set to myApp. Aspen Flare System Analyzer Object Reference The following subsections summarize the methods and properties available for each object available within Aspen Flare System Analyzer. They are ordered purely alphabetically. For each object the attributes comprise the type (or class) of object followed by the access characteristics which may be read-only or read/write. In general, data has the read/write attribute and calculated values have the read-only attribute. Each method is shown with the method name including any arguments, a description of the method and a description of the arguments. Each property is shown with the property name including any arguments, a description of the property, the property attributes and a description of the arguments. Optional arguments are shown in square brackets []. Many objects support a PropertyByName property. In such cases a further table gives the valid property names which are case insensitive as well as the property attributes and the units of measure where appropriate. The property names will generally match the field descriptions on the corresponding views but they never contain any space characters. 8 Automation 127 Application Description : Application object Methods Name Description Arguments OpenModel(fileName As String) Open an Aspen Flare System Analyzer model fileName = Model filename SaveModel(fileName As String) Save an Aspen Flare System Analyzer model fileName = Model filename DoImport(imType As importType, source As String, Definition As String, Flag As Reserved) As Integer Import an Aspen Flare System Analyzer Model imType = 0,1,2 for xml,xls,mdb files source = Import filename Definition = Definition filename Flag = 0 DoExport(exType As exportType, source As String, Definition As String, Flag As Reserved) As Integer Export an Aspen Flare System Analyzer Model exType = 0,1,2 for xml, xls, mdb files source = Export filename Definition = Definition filename Flag = 0 LaunchFlarenet([fileName As String]) Display the Aspen Flare System Analyzer application window fileName = Model filename Quit() Quit Aspen Flare System Analyzer. Please call this method before your scripts end. Note: The LaunchFlarenet method only launches the Aspen Flare System Analyzer Graphical User Interface (GUI) in a separate process which cannot be controlled directly. The Quit method cannot terminate the GUI opened by the LaunchFlarenet method. Properties Name Description Attributes Arguments Bleeds Collection of flow bleed objects IBleeds, read- only Components Collection of component objects IComponents, read-only Connectors Collection of connector objects IConnectors, read-only ControlValves Collection of control valve objects IControlValves, read-only HorizontalSeparat ors Collection of horizontal separator objects IHorizontalSepar ators, read-only Nodes Collection of node objects INodes, read- only OrificePlates Collection of orifice plate objects IOrificePlates, read-only Pipes Collection of pipe objects IPipes, read-only ReliefValves Collection of relief valve objects IReliefValves, read-only 128 8 Automation Name Description Attributes Arguments Scenarios Collection of scenario objects IScenarios, read- only Solver Solver object ISolver, read- only Tees Collection of tee objects ITees, read-only Tips Collection of flare tip objects ITips, read-only VerticalSeparators Collection of vertical separator objects IVerticalSeparato rs, read-only Bleed Description : Flow bleed object Attributes : IBleed, read-only Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on bleed Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on bleed Properties Name Description Attributes Arguments PropertyByName(Wha t As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Ignored fntYesNo, read/write Location String, read/write Name String, read/write OfftakeMaximum kg/hr Double, read/write OfftakeMinimum kg/hr Double, read/write OfftakeMultiplier Double, read/write OfftakeOffset kg/hr Double, read/write PressureDrop bar Double, read/write Bleeds Description : Collection of flow bleed objects Attributes : IBleeds, read-only 8 Automation 129 Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new bleed Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete (What) Delete a bleed What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item (What) Indexed item in the collection IBleed, read- only What = Index as Name (String) or Number (Integer/Long) Component Description : Component object Attributes : IComponent, read-only Methods Name Description Arguments Clear (Optional Cname compName As String = Nothing) Clear all component data Cname = Component Name. If omitted all components will be cleared. EstimateUnknown Estimate all unknown component data Properties Name Description Attributes Arguments IsValid Validate component data is complete Boolean, read-only PropertyByName(W hat As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes AcentricFactor Double, read/write AcentricFactorSrk Double, read/write CharacteristicVolume m3/kgmole Double, read/write CriticalPressure bar abs Double, read/write CriticalTemperature K Double, read/write 130 8 Automation Name Units Attributes CriticalVolume m3/kgmole Double, read/write EnthalpyCoefficients kJ/kgmole kJ/kgmole/K kJ/kgmole/K2 kJ/kgmole/K3 kJ/kgmole/K4 kJ/kgmole/K5 Double(1 To 6), read/write EntropyCoefficient Double, read/write Id Integer, read/write MolecularWeight Double, read/write Name String, read/write NormalBoilingPoint K Double, read/write StandardDensity kg/m3 Double, read/write Type fntCompType, read/write WatsonK Double, read/write ViscosityCoefficient Double(1 To 2), read/write Components Description : Collection of component objects Attributes : IComponents, read-only Methods Name Description Arguments AddLibrary(What As Variant) Add a library component What = Component identifier as either name (String) or ID (Integer/Long) AddHypothetical(What As String) Add a named hypothetical component What = Name for new component Delete(What) Delete a component What = Index as component as either Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IComponent, read-only What = Index as Name (String) Or Number (Integer/Long) Connector Description : Connector node object Attributes : IConnector, read-only 8 Automation 131 Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on connector Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on connector Properties Name Description Attributes Arguments PropertyByName(W hat As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Angle radians Double, read/write Ignored fntYesNo, read/write Length m Double, read/write Location String, read/write Name String, read/write Connectors Description : Collection of connector objects Attributes : IConnectors, read-only Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new connector Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete (What) Delete a connector What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IConnector, read- only What =Index as Name (String) Or Number (Integer/Long) 132 8 Automation ControlValve Description : Control valve object Attributes : IControlValve, read-only Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on control valve Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on control valve Properties Name Description Attributes Arguments PropertyByName(W hat As String, [Scenario]) Property value for a named property Variant, read/write What = Property name Scenario = Scenario Index as Name (String) or Number (Integer/Long) PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Composition fractions Double (1 To ?), read/write CompositionBasis fntCompBasis, read/write Energy kJ/hr Double, read-only Enthalpy kJ/kgmole Double, read-only Entropy kJ/kgmole/K Double, read-only FlangeDiameter mm Double, read/write FluidType fntCompType, read/write Ignored fntYesNo, read/write Location String, read/write LockMabp fntYesNo, read/write Mabp bar abs Double, read-only MassFlow kg/hr Double, read/write MolecularWeight Double, read/write Name String, read/write OutletMachNumber Double, read-only OutletSonicVelocity m/s Double, read-only OutletTemperature C Double, read-only OutletTemperatureSpecification C Double, read-only OutletVelocity m/s Double, read-only ReliefPressure bar abs Double, read-only StaticOutletPressure bar abs Double, read-only 8 Automation 133 Name Units Attributes StaticInletPipePressureDrop bar Double, read-only Temperature C Double, read-only TemperatureSepcification fntTempSpec, read/write TotalOutletPressure bar abs Double, read-only TotalInletPipePressureDrop bar Double, read-only VapourFraction molar fraction Double, read-only ControlValves Description : Collection of control valve objects Attributes : IControlValves Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new control valve Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a control valve What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IControlValve, read-only What = Index as Name (String) or Number (Integer/Long) HorizontalSeparator Description : Horizontal separator object Attributes : IHorizontalSeparator, read-only Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on horizontal separator Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on horizontal separator Properties 134 8 Automation Name Description Attributes Arguments PropertyByName( What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read- only Named Properties For PropertyByName() Name Units Attributes Diameter mm Double, read/write Ignored fntYesNo, read/write LiquidLevel mm Double, read/write Location String, read/write Name String, read/write HorizontalSeparators Description : Collection of horizontal separator objects Attributes : IHorizontalSeparators, read-only Method Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new horizontal separator Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a horizontal separator What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IHorizontalSepar ator, read-only What =Index as Name (String) Or Number (Integer/Long) Nodes Description : Collection of all node objects Attributes : INodes, read-only Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only 8 Automation 135 OrificePlate Description : Orifice plate object Attributes : IOrificePlate, read-only Method Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on orifice plate Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on orifice plate Properties Name Description Attributes Arguments PropertyByName (What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Variant array of all the property names Variant, read-only Named Properties For PropertyByName() Name Units Attributes Diameter mm Double, read/write DratioIn Double, read/write DratioOut Double, read/write Ignored fntYesNo, read/write Location String, read/write Name String, read/write OrificePlates Description : Collection of orifice plate objects Attributes : IOrificePlates, read-only Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new orifice plate Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete an orifice plate What = Index as Name (String) or Number (Integer/Long) Properties 136 8 Automation Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(Wha t) Indexed item in the collection IOrificePlate, read- only What =Index as Name (String) Or Number (Integer/Long) Pipe Description : Pipe object Attributes : IPipe, read-only Methods Name Description Arguments AddFitting(FittingName As String, [Count As Long = 1]) Add a fitting to the fittings list FittingName = Name of fitting defined in the pipe fittings database Count = Number of fittings of this type to add Connect(ConnectionIdx as fntPipeEnd, Node As Object, NodeConnectionIdx as fntNodeEnd) Connect to a node ConnectionIdx = Connection on pipe Node = Node to connect to NodeConnectionIdx = Connection on node DeleteAllFittings() Delete all fittings from the fittings list DeleteFittingByIndex(Fi ttingIndex As Long) Delete a fitting from the fittings list FittingIndex = Index of fitting in the fittings list to delete DeleteFittingByName(Fi ttingName As String, [Count As Long = 1]) Delete a fitting from the fittings list FittingName = Name of fitting defined in the pipe fittings database Count = Number of fittings of this type to delete Disconnect(ConnectionI dx As fntPipeEnd) Disconnect from a node ConnectionIdx = Connection on pipe GetFittingCount() As Long Get number of fittings in the fitting list GetFittingName(FittingI ndex As Long) As String Get name of indexed pipe fitting FittingIndex = Index of fitting in the fittings list to retrieve name for Properties 8 Automation 137 Name Description Attributes Arguments PropertyByName( What As String, [Scenario], [Phase], [PipeEnd]) Property value for a named property Variant, read /write What = Property name Scenario = Scenario Index as Name (String) or Number (Integer/Long) Phase = Phase Index (fntFluidPhase) PipeEnd = Pipe end (fntPipeEnd) PropertyNames Collection of all the property names String, read- only UseFittings Flag to indicate if a fittings list is used instead of loss coefficients Boolean, read/write Named Properties For PropertyByName() Name Units Attributes AccelerationPressureDrop bar Double, read-only AmbientTemperature C Double, read-only CanSize fntYesNo, read/write MoleFractions Double(1 To ?), read- only Density kg/m3 Double, read-only Duty kJ/hr Double, read-only ElevationChange m Double, read/write ElevationPressureDrop bar Double, read-only Emissivity Double, read-only Energy kJ/hr Double, read-only Enthalpy kJ/kgmole Double, read-only Entropy kJ/kgmole/K Double, read-only EquivalentLength m Double, read-only ExternalDuty W Double, read/write ExternalHeatTransferCoefficient W/m2/K Double, read-only ExternalRadiativeHeatTransferCoefficient W/m2/K Double, read-only ExternalTemperature C Double, read-only FittingsLossConstant Double, read-only FittingsLossMultiplier Double, read-only FittingsPressureDrop bar Double, read-only FlowRegime fntFlowRegime, read- only FrictionFactor Double, read-only FrictionPressureDrop bar Double, read-only HeatCapacity kJ/kgmole/K Double, read-only HeatTransfer kJ/hr Double, read-only Ignored fntYesNo, read/write IgnoreHeadRecovery fntYesNo, read/write 138 8 Automation Name Units Attributes InsulationName String, read/write InsulationThickness mm Double, read/ write InsulationThermalConductivity W/m/K Double, read/write InternalDiameter mm Double, read/write Length m Double, read/write LengthMultiplier Double, read/write Location String, read/write MachNumber Double, read-only MassFlow kg/hr Double, read/write Material fntPipeMaterial, read/write MolecularWeight Double, read-only MolarFlow kgmole/hr Double, read-only Name String, read/write Noise dB Double, read-only NominalDiameter String, read/write OutletTemperatureSpecification C Double, read/write OverallHeatTransferCoefficient W/m2/K Double, read-only UsePipeClass fntYesNo, read/write PhaseFraction Double, read-only PressureDrop bar Double, read-only RatedMassFlow kg/hr Double, read-only ReynoldsNumber Double, read-only RhoV2 kg/m/s2 Double, read-only Roughness mm Double, read/write StaticPressure bar abs Double, read-only Schedule String, read/write SurfaceTension dynes/cm Double, read-only TailPipe fntYesNo, read/write Temperature C Double, read-only ThermalConductivity W/m/K Double, read-only TotalPressure bar abs Double, read-only VapourFraction molar fraction Double, read-only Velocity m/s Double, read-only Viscosity cP Double, read-only WallThermalConductivity W/m/K Double, read/write WallTemperature C Double, read-only WallThickness mm Double, read/write WindSpeed m/s Double, read/write Zfactor Double, read-only Pipes Description : Collection of pipes 8 Automation 139 Attributes : IPipes Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new pipe Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a pipe What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(Wha t) Indexed item in the collection IPipe, read-only What = Index as Name (String) or Number (Integer/Long) ReliefValve Description : Relief valve object Attributes : IReliefValve, read-only Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, pipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on relief valve Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on relief valve Properties Name Description Attributes Arguments PropertyByName (What As String, [Scenario]) Property value for a named property Variant, read/write What = Property name Scenario = Scenario Index as Name (String) or Number (Integer/Long) PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Composition fractions Double (1 To ?), read/write 140 8 Automation Name Units Attributes CompositionBasis fntCompBasis, read/write Contingency fntContingency, read/write Energy kJ/hr Double, read-only Enthalpy kJ/kgmole Double, read-only Entropy kJ/kgmole/K Double, read-only FlangeDiameter mm Double, read/write FluidType fntCompType, read/write HemCd Double, read/write HemLiqCd Double. Read/write Ignored fntYesNo, read/write Kb Double, read/write Location String, read/write LockMabp fntYesNo, read/write LockReliefPressure fntYesNo, read/write LockRatedMassFlow fntYesNo, read/write Mabp bar abs Double, read-only MassFlow kg/hr Double, read/write Mawp bar abs Double, read/write MechanicalPressure bar abs Double, read/write MolecularWeight Double, read/write Name String, read/write Orifice String, read/write OutletMachNumber Double, read-only OutletSonicVelocity m/s Double, read-only OutletTemperature C Double, read-only OutletTemperatureSpecification C Double, read-only OutletVelocity m/s Double, read-only RatedMassFlow kg/hr Double, read/write ReliefPressure bar abs Double, read-only SizingBackPressure Bar abs Double, read/write SizingMethod Integer, read/write StaticOutletPressure bar abs Double, read-only StaticInletPipePressureDrop bar Double, read-only Temperature C Double, read-only TemperatureSpecification fntTempSpec, read/write TotalOutletPressure bar abs Double, read-only TotalInletPipePressureDrop bar Double, read-only ValveArea mm2 Double, read/write ValveCount Integer, read/write ValveType fntPsvType, read/write 8 Automation 141 Name Units Attributes VapourFraction molar fraction Double, read-only ReliefValves Description : Collection of relief valve objects Attributes : IReleifValves Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new relief valve Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinated on the Process Flowsheet (Twips) Delete(What) Delete a relief valve What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IReliefValve, read-only What = Index as Name (String) or Number (Integer/Long) Scenario Description : Scenario object Attributes : IScenario, read-only Properties Name Description Attributes Arguments PropertyByName (What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Variant array of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes AtmosphericPressure bar abs Double, read/write Calculate fntYesNo, read/write HeaderLiquidVelocityLimit m/s Double, read/write HeaderMachLimit Double, read/write HeaderNoiseLimit dB Double, read/write HeaderRhoV2Limit kg/m/s2 Double, read/write 142 8 Automation Name Units Attributes HeaderVapourVelocityLimit m/s Double, read/write Name String, read/write TailpipeLiquidVelocityLimit m/s Double, read/write TailpipeMachLimit Double, read/write TailpipeNoiseLimit dB Double, read/write TailpipeRhoV2Limit kg/m/s2 Double, read/write TailpipeVapourVelocityLimit m/s Double, read/write Scenarios Description : Collection of scenario objects Attributes : IScenarios, read-only Methods Name Description Arguments Add([Name As String], [CloneIdx As Long = 1]) Add a new scenario Name = New scenario name CloneIdx = Index of scenario to copy data from for initialization Delete(What) Delete a scenario What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Active Set active scenario What = Index as Name (String) or Number (Integer/Long) ActiveScenario Get active scenario IScenario, read- only Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IScenario, read- only What = Index as Name (String) or Number (Integer/Long) Solver Description : Solver object Attributes : ISolver, read-only Methods Name Description Arguments Halt Stop calculations Start Start calculations Properties 8 Automation 143 Name Description Attributes Arguments IsActive Get calculation status Boolean, read- only PropertyByName( What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes AmbientTemperature C Double, read/write AtmosphericPressure bar abs Double, read/write CalculationMode fntCalcMode, read/write CheckChokedFlow fntYesNo, read/write Elements Integer, read/write EnableHeatTransfer fntYesNo, read/write EnthalpyMethod fntEnthMethod, read/write InitialPressure bar abs Double, read/write KineticEnergyBasis fntKeBasis, read/write LengthMultiplier Double, read/write LoopIteration Integer, read-only LoopIterationLimit Integer, read/write LoopTolerance % Double, read/write PressureDropMethod fntPresDropMethod(0 to 2), read/write PropertyIteration Integer, read-only PropertyIterationLimit Integer, read/write PropertyTolerance % Double, read/write ScenarioMode fntScenarioMode, read/write UnitOperationTolerance % Double, read/write UseKineticEnergy fntYesNo, read/write UseRatedFlow fntYesNo, read/write VleMethod fntVleMethod, read/write WindSpeed Double, read/write Tee Description : Tee object Attributes : ITee, read-only Methods Name Description Arguments 144 8 Automation Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection to tee Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on tee Properties Name Description Attributes Arguments PropertyByName( What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Angle fntTeeAngle, read/write Body fntTeeEnd, read/write Ignored fntYesNo, read/write Location String, read/write Name String, read/write Tees Description : Collection of tee objects Attributes : ITees, read-only Method Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new tee Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a tee What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection ITee, read-only What = Index as Name (String) Or Number (Integer/Long) 8 Automation 145 Tip Description : Flare tip object Attributes : ITip, read-only Methods Name Description Arguments AddCurve() Add a pressure drop curve AddCurvePoint(Index As Long) Append a point to a pressure drop curve Index = Index of curve Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection to tee Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe DeleteCurve(Index As Long) Delete a pressure drop curve Index = Index of curve DeleteCurvePoint(Index As Long, Which As Long) Index = Index of curve Which = Index of point Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on flare tip Properties Name Description Attributes Arguments CurveMolWt(Inde x As Long) Molecular weight of indexed pressure drop curve Double, read/write Index = Curve index CurvePointMassF low(Index As Long, Which As Long) Mass flow of point on a pressure drop curve (kg/hr) Double, read/write Index = Index of curve Which = Index of point CurvePointPressu reDrop(Index As Long, Which As Long) Pressure drop of point on a pressure drop curve (bar) Double, read/write Index = Index of curve Which = Index of point PropertyByName (What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only Named Properties For PropertyByName() Name Units Attributes Diameter mm Double, read/write Ignored fntYesNo, read/write K Double, read/write Kbasis fntKbasis, read/write Location String, read/write Name String, read/write Reference Temperature Double, read/write 146 8 Automation Name Units Attributes UseCurves fntYesNo, read/write Tips Description : Collection of flare tip objects Attributes : ITips, read-only Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new flare tip Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a flare tip What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection ITip, read-only What =Index as Name (String) Or Number (Integer/Long) VerticalSeparator Description : Vertical separator object Attributes : IVerticalSeparator, read-only Methods Name Description Arguments Connect(ConnectionIdx As fntNodeEnd, Pipe As IPipe, PipeConnectionIdx As fntPipeEnd) Connect to a pipe ConnectionIdx = Connection on vertical separator Pipe = Pipe to connect to PipeConnectionIdx = Connection on pipe Disconnect(ConnectionIdx As fntNodeEnd) Disconnect from a pipe ConnectionIdx = Connection on vertical separator Properties Name Description Attributes Arguments PropertyByName (What As String) Property value for a named property Variant, read/write What = Property name PropertyNames Collection of all the property names String, read-only 8 Automation 147 Named Properties For PropertyByName() Name Units Attributes Diameter mm Double, read/write Ignored Boolean, read/write Location String, read/write Name String, read/write VerticalSeparators Description : Collection of vertical separator objects Attributes : IVerticalSeparators, read-only Methods Name Description Arguments Add ([Name As String], [Xcoordinate As Single = 0] [Ycoordinate As Single = 0]) Add a new vertical separator Name: If omitted a new name is automatically generated Xcoordinate = X coordinate on the Process Flowsheet (Twips) Ycoordinate = Y coordinate on the Process Flowsheet (Twips) Delete(What) Delete a vertical separator What = Index as Name (String) or Number (Integer/Long) Properties Name Description Attributes Arguments Count Number of items in the collection Long, read-only Item(What) Indexed item in the collection IVerticalSeparator , read-only What =Index as Name (String) Or Number (Integer/Long) Example – Automation In Visual Basic This example shows how that Aspen Flare System Analyzer can be used as an automation server by a program that analyses an Aspen Flare System Analyzer model to search for the maximum and minimum values of a user defined named property within all the pipes. Note: Although Visual Basic 6 is recommended for this example, you may create the Automation application in the Visual Basic editor provided in Microsoft Excel 2007 ® (or later) and Microsoft Word 2007 ® (or later). 1 Open a new project in Visual Basic 6 ® . From the New tab of the New Project property view; select the Standard EXE icon and click OK. Your screen should appear similar as below. 148 Fig 8.6 2 By default you should have a form associated with th Name field of the frmBounds. Note: This complete example has also been pre \Samples\Ole\Vb 3 In the Caption field typ Property Bounds form. 4 Before adding objects to the for different objects that will be r Properties w value such that the 5 From the Tool Box select shown below. By default you should have a form associated with the project. In the field of the Properties window, give the form the name: This complete example has also been pre-built and is located in the Vb\Bounds directory. In the Caption field type: Aspen Flare System Analyzer Property Bounds. This caption should now appear in the title bar of the Before adding objects to the form, resize the view to accommodate the different objects that will be required. In the Width filed found in the window, change the width of the form to 6900 value such that the form is sufficiently wide to fully display the caption. From the Tool Box select Text Box; create a text box on the form as . 8 Automation e project. In the give the form the name: built and is located in the Model Pipe . This caption should now appear in the title bar of the , resize the view to accommodate the filed found in the 00 or to any is sufficiently wide to fully display the caption. te a text box on the form as 8 Automation Fig 8.7 6 Ensure that the text box is the active control. This can be done in one of two ways: Select the text box on the form so that the object guides appear around the object. From the box of the text box you have just created. 7 In the Properties windows, set the name of the text box as ebModelName default text that appears inside the edit box by entering a new name in the Text field. 8 You may add a label to the form. i.e. to identify the object from others, by selecting the text box you have just created. 9 Ensuring that the label control is active using one of the methods suggested in step 6, go to the in the Caption Ensure that the text box is the active control. This can be done in one of Select the text box on the form so that the object guides appear around the object. box found at the top of the Properties window, of the text box you have just created. In the Properties windows, set the name of the text box as ebModelName in the Name field. If you wish, you may also change the default text that appears inside the edit box by entering a new name in field. You may add a label to the form. i.e. to identify the object from others, by selecting the Label tool and drawing the label on the form just above the text box you have just created. Ensuring that the label control is active using one of the methods suggested in step 6, go to the Properties Window and change the text Caption field to Model Name. 149 Ensure that the text box is the active control. This can be done in one of Select the text box on the form so that the object guides appear around select the name In the Properties windows, set the name of the text box as lso change the default text that appears inside the edit box by entering a new name in You may add a label to the form. i.e. to identify the object from others, by abel on the form just above the Ensuring that the label control is active using one of the methods and change the text 150 Fig 8.8 10 Add the following objects to the form using the previously described methods. Fig 8.9 11 Only two more objects are required on the form. Select the Button control from the tool bar and add two buttons to the form as shown below. Add the following objects to the form using the previously described Only two more objects are required on the form. Select the control from the tool bar and add two buttons to the form as below. 8 Automation Add the following objects to the form using the previously described Only two more objects are required on the form. Select the Command control from the tool bar and add two buttons to the form as 8 Automation Fig 8.10 12 You are now ready to begin defining the events behind the form and objects. You may enter the code environment using a number of methods Click View Code Select Code from the Double-click the You are now ready to begin defining the events behind the form and objects. You may enter the code environment using a number of methods View Code in the Project window. from the View menu. click the frmBounds form. 151 You are now ready to begin defining the events behind the form and objects. You may enter the code environment using a number of methods: 152 Fig 8.11 The Private Sub Form_Load() you enter the code environment by double 13 Begin by declaring the following variables under the Option Explicit Declaration. Fig 8.12 14 Add a reference to the Aspen Flare System Analyzer type library to allow access to predefined constant menu. Private Sub Form_Load() method definition will only be visible if you enter the code environment by double-clicking the form. Begin by declaring the following variables under the Option Explicit Add a reference to the Aspen Flare System Analyzer type library to allow access to predefined constants by selecting References from the 8 Automation method definition will only be visible if clicking the form. Begin by declaring the following variables under the Option Explicit Add a reference to the Aspen Flare System Analyzer type library to allow from the Project 8 Automation Fig 8.13 15 The first subroutine should already be declared. The subroutine is the first subroutine called once the program is run. It is usually used to initializ Enter the following code into the Code Private Sub Form_Load() ebModelName.Text = "" ebPropertyName.Text = "" ebMinValue.Text = "" ebMaxValue.Text = "" End Sub 16 The next section of code to be added is what will occur when the name of the model is changed in the Code Private Sub ebModelName_Validate(Cancel As Boolean) ModelName = ebModelName.Text End Sub The first subroutine should already be declared. The Form_Load subroutine is the first subroutine called once the program is run. It is usually used to initialize the variables and objects used by the program. Enter the following code into the Form_Load subroutine. Explanation Private Sub Form_Load() Signifies the start of the form load subroutine. You do not have to add as it should already be there. elName.Text = "" ebPropertyName.Text = ebMinValue.Text = "" ebMaxValue.Text = "" Clears all the text fields. Signifies the end of the initialization subroutine. This line does not need to be added. ection of code to be added is what will occur when the name of the model is changed in the ebModelName box. Explanation Private Sub ebModelName_Validate(Cancel As Boolean) Signifies the start of the subroutine. ModelName = ebModelName.Text Copies the entered name for the model to the String Variable ModelName Signifies the end of the subroutine. 153 Form_Load subroutine is the first subroutine called once the program is run. It is e the variables and objects used by the program. Signifies the start of the form load subroutine. You do not have to add as it should already be Signifies the end of the initialization subroutine. This line does not need to be added. ection of code to be added is what will occur when the name of Signifies the start of the subroutine. e entered name for the model to the String Variable ModelName Signifies the end of the subroutine. 154 8 Automation 17 The next section of code to be added is what will occur when the desired property is changed in the ebPropertyName box. Code Explanation Private Sub ebPropertyName_Validate(Canc el As Boolean) Signifies the start of the subroutine. PropertyName = ebPropertyName.Text Copies the entered name for the property to the String Variable PropertyName End Sub Signifies the end of the subroutine. 18 The final two routines define the actions of the two buttons: btnUpdate and btnExit. Code Explanation Private Sub btnUpdate_Click() Signifies the start of the subroutine. Dim OwnedByMe As Boolean Dim MaxVal As Double Dim MinVal As Double Dim Pipe As AspenTech.FlareSystemAnalyzer.I nterfacesObject Dim iPipe As Long Dim npipes As Long Dim WorkVal As Double Declare work variables. On Error Resume Next Prevents an error from being raised if, for example, an invalid name for the property is selected. If Trim$(ModelName) = "" Then OwnedByMe = False Set FnApp = GetObject(, "AspenTech.FlareSystemAnalyzer. Interfaces.Application") Else Set FnApp = CreateObject("AspenTech.FlareSy stemAnalyzer.Interfaces.Applica tion") OwnedByMe = True FnApp.OpenModel ModelName End If If a model name is defined then opens the model defined by the String variable ModelName; otherwise, connects to the currently running instance of Aspen Flare System Analyzer. If Not FnApp Is Nothing Then Ensure successful connection to the Application object. MaxVal = -10000000000# MinVal = 10000000000# Initializes the maximum and minimum values to values outside the range of possible values. npipes = FnApp.Pipes.Count For iPipe = 1 To npipes Set pipe = FnApp.Pipes.Item(iPipe) Loop through all the pipes in the model. 8 Automation 155 Code Explanation WorkVal = Pipe.PropertyByName(PropertyNam e) Get the property named and stores in the String variable PropertyName. If WorkVal <> fntVariableStatus_fntUnknownVal ue Then Check for an unknown value. Do not consider the value further if it is unknown. If WorkVal > MaxVal Then MaxVal = WorkVal Update maximum value. If WorkVal < MinVal Then MinVal = WorkVal Update minimum value. End If Next iPipe End of loop and value update. ebMinValue.Text = Format$(MinVal, "0.000e+00") ebMaxValue.Text = Format$(MaxVal, "0.000e+00") Update the displayed values in the ebMinValue and ebMaxValue Text boxes. Set FnApp = Nothing End If Disconnect the Application object. End Sub Signifies the end of the subroutine. Private Sub btnExit_Click() Signifies the start of the subroutine. Set FnApp = Nothing Releases the connection to Aspen Flare System Analyzer. Unload Me End Unload the form and end the program. End Sub Signifies the end of the subroutine. 19 You are now ready to compile and run the program. Before you begin, please ensure that you have a copy of Aspen Flare System Analyzer on the computer. 20 To compile the program do one of the following: - Click the Start button... - Select Start from the Run menu. - Press <F5> from the keyboard. Visual Basic will inform you of any errors that occur during compile time. Updating Automation Files From Previous Versions Aspen Flare System Analyzer now uses a new .Net interface to provide access to the software via automation. As a result a few changes have to be made in the way the VB6 application code accesses the available methods and properties. If you have an existing application, it may fail to run with the new 156 8 Automation interface. Below are some notes on what needs to be updated in your applications to ensure it runs successfully in this new version. 1 Currently Application.Visible can only be set to False. The user cannot make the application visible. The application will be running as usual in the background. The LaunchFlarenet method described in this chapter can be used to launch a separate process showing the graphical user interface. This process can only be controlled manually and needs to be manually terminated as well. 2 In the declarations Integer should be replaced by Long. 3 Objects cannot be enumerated in a collection. Previously you could write the following code: Dim Pipe As Object For Each Pipe In FnApp.Pipes WorkVal = Pipe.PropertyByName(PropertyName) … Next Now this type of code must be written as follows: Dim iPipe As Long Dim npipes As Long For iPipe = 1 To npipes Set pipe = FnApp.Pipes.Item(iPipe) WorkVal = pipe.PropertyByName(PropertyName) … Next iPipe 4 In VB6 enum values are actually constants, thus Enum members can be used directly without the Enum type, e.g. fntUnknownValue. In VB.Net the Enum type is just a type, not a constant. Also in VB6 it is not possible to have items of the same name under different Enums, e.g. fntFlowRegime.fntUnknownValue and fntVariableStatus.fntUnknownValue. Therefore to avoid this issue, MicroSoft determines that all Enum items should be renamed by having their Enum type as prefix followed by character _. Thus existing code must be modified to include the new Enum item names. For instance, instead of fntUnknownValue for Variable Status, we now have fntVariableStatus_fntUnknownValue. Please look in the AspenTech.FlareSystem.Analyzer Object Browser for the new Enum items’ names. 9 Theoretical Basis 157 9 Theoretical Basis Pressure Drop Pipe Pressure Drop Method Vapor Phase Pressure Drop Methods Pressure drop can be calculated either from the theoretically derived equation for isothermal flow of a compressible fluid in a horizontal pipe 2 : ( ) 0 2 2 In 2 2 1 2 2 2 1 2 = | . | \ | | | . | \ | + ÷ + | | . | \ | | . | \ | a G L f RT P P M P P a G f | 9.1 weight Molecular M e Temperatur T length Equivalent L diameter Internal factor friction Fanning f constant gas Universal R pressure Downstream P pressure Upstream P pipe of area sectional Cross a flow Mass G where f = = = = = = = = = = | 2 1 : 158 9 Theoretical Basis Or from the theoretically derived equation for adiabatic flow of a compressible fluid in a horizontal pipe 2 : | | . | \ | + ÷ ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | | . | \ | ÷ ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | . | \ | + = | | . | \ | 1 2 2 2 1 2 1 1 In γ 1 γ 1 2γ 1 - γ V V V V G a V P L Af f | 9.2 heats specific of Ratio length Equivalent L diameter Internal factor friction Fanning f volume specific Downstream V volume specific Upstream V constant gas Universal R pressure Upstream P pipe of area sectional Cross a flow Mass G where f = = = = = = = = = = γ : 2 1 1 | The friction factor is calculated using an equation appropriate for the flow regime. These equations correlate the friction factor to the pipe diameter, Reynolds number and roughness of the pipe 4 : Turbulent Flow (Re > 4000) The friction factor may be calculated from either the Round equation: ( ) ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ + = 5 . 6 135 . 0 log 61 . 3 1 e f Re Re f | 9.3 roughness pipe Absolute e diameter Internal number Reynolds Re factor friction Fanning f where f = = = = | : Or from the Chen 21 equation: ( ) ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | | . | \ | | . | \ | + ÷ ÷ = 8981 . 0 1098 . 1 149 . 7 8257 . 2 / log 0452 . 5 7065 . 3 / log 4 1 Re e Re e f f | | 9 Theoretical Basis 159 9.4 roughness pipe Absolute e diameter Internal number Reynolds Re factor friction Fanning f where f = = = = | : Transition Flow (2100 s Re s 4000) ) ` ¹ ¹ ´ ¦ | | . | \ | ÷ ÷ | | . | \ | ÷ | | . | \ | ÷ = Re e Re e Re e f f 0 . 13 7 . 3 log 02 . 5 7 . 3 log 02 . 5 7 . 3 log 0 . 4 1 | | | 9.5 roughness pipe Absolute e diameter Internal number Reynolds Re factor friction Fanning f where f = = = = | : Laminar Flow (Re < 2100) Re f f 16 = 9.6 number Reynolds Re factor friction Fanning f where f = = : The Moody friction factor is related to the Fanning friction factor by: f m f f - = 4 9.7 factor friction Moody f factor friction Fanning f where m f = = : 160 9 Theoretical Basis 2-Phase Pressure Drop Although the Beggs and Brill method was not intended for use with vertical pipes, it is nevertheless commonly used for this purpose, and is therefore included as an option for vertical pressure drop methods. Beggs and Brill The Beggs and Brill 9 method is based on work done with an air-water mixture at many different conditions, and is applicable for inclined flow. In the Beggs and Brill correlation, the flow regime is determined using the Froude number and inlet liquid content. The flow map used is based on horizontal flow and has four regimes: segregated, intermittent, distributed and transition. Once the flow regime has been determined, the liquid hold-up for a horizontal pipe is calculated, using the correlation applicable to that regime. A factor is applied to this hold-up to account for pipe inclination. From the hold-up, a two-phase friction factor is calculated and the pressure gradient determined. Fig 9.1 The boundaries between regions are defined in terms of two constants and the Froude number 10 : ( ) 3 2 1 0207 . 0 481 . 0 757 . 3 62 . 4 exp x x x L ÷ ÷ ÷ ÷ = 9.8 ( ) 5 3 2 2 000625 . 0 0179 . 0 609 . 1 602 . 4 061 . 1 exp x x x x L + ÷ ÷ ÷ = 9 Theoretical Basis 161 9.9 ( ) ( ) flowrate volumetric situ In q q q q content liquid Input In x where gas liquid liquid = + = = = / λ λ : According to Beggs and Brill: 1 If the Froude number is less than L 1 , the flow pattern is segregated. 2 If the Froude number is greater than both L 1 and L 2 , the flow pattern is distributed. 3 If the Froude number is greater than L 1 and smaller than L 2 the flow pattern is intermittent. Dukler Method The Dukler 10 method breaks the pressure drop into three components - Friction, Elevation and Acceleration. The total pressure drop is the sum of the pressure drop due to these components: A E F Total P P P P A + A + A = A 9.10 on accelerati to due pressure in Change P elevation to due pressure in Change P friction to due pressure in Change P pressure in change Total P where A E F Total = A = A = A = A : The pressure drop due to friction is: D g V L f P c m m TP F 144 ρ 2 2 = A 9.11 ) ( ) / 2 . 32 ( g ) / ( ρ ) / ( ) ( ) ( : 2 3 ft pipe of diameter Inside D s lbf ft lbm constant nal Gravitatio ft lb mixture phase two of Density s ft velocity equal assuming pipeline in mixture phase two the of Velocity V ft pipeline the of length Equivalent L y empiricall determined factor friction phase Two f where c m m TP = ÷ ÷ = ÷ = ÷ = = ÷ = 162 9 Theoretical Basis The pressure drop due to elevation is as follows: 144 ρ ¿ = A H E P L h E 9.12 changes elevation of Sum H density Liquid y empiricall determined factor head Liquid E where L h = = = ¿ ρ ) ( : The pressure drop due to acceleration is usually very small in oil/gas distribution systems, but becomes significant in flare systems: ( ( ¸ ( ¸ | | . | \ | + ÷ ÷ | | . | \ | + ÷ = A θ cos ρ 1 ρ ρ 1 ρ 144 1 2 2 2 2 2 US L LPL L L GPL g DS L LPL L L GPL g c A R Q R Q R Q R Q A g P 9.13 bend pipe the of Angle capacity pipeline of percentage a as pipeline in holdup Liquid R hr ft pressure and e temperatur pipeline at flowing liquid of Volume Q hr ft pressure and e temperatur pipeline at flowing gas of Volume Q density Gas area sectional Cross A where L LPL GPL g = = = = = ÷ = θ ) / ( ) / ( ρ : 3 3 Orkiszewski Method The Orkiszewski 11,12 method assumes there are four different flow regimes existing in vertical two-phase flow - bubble, slug, annular-slug transition and annular-mist. The bubble flow regime consists mainly of liquid with a small amount of a free-gas phase. The gas phase consists of small, randomly distributed gas bubbles with varying diameters. The gas phase has little effect on the pressure gradient (with the exception of its density). In the slug flow regime, the gas phase is most pronounced. The gas bubbles coalesce and form stable bubbles of approximately the same size and shape. The gas bubbles are separated by slugs of a continuous liquid phase. There is a film of liquid around the gas bubbles. The gas bubbles move faster than the liquid phase. At high flow velocities, the liquid can become entrained in the gas bubbles. The gas and liquid phases may have significant effects on the pressure gradient. Transition flow is the regime where the change from a continuous liquid phase to a continuous gas phase occurs. In this regime, the gas phase becomes 9 Theoretical Basis 163 more dominant, with a significant amount of liquid becoming entrained in the gas phase. The liquid slug between the gas bubbles virtually disappears in the transition regime. In the annular-mist regime, the gas phase is continuous and is the controlling phase. The bulk of the liquid is entrained and carried in the gas phase. Orkiszewski defined bubble flow, slug flow, mist flow and gas velocity numbers which are used to determine the appropriate flow regime. If the ratio of superficial gas velocity to the non-slip velocity is less than the bubble flow number, then bubble flow exists, for which the pressure drop is: D g R V f P c L sL L tp 2 ρ 2 | | . | \ | = A 9.14 ) ( ) / 2 . 32 ( ) / ( ) / ( ρ ) / ( : 2 3 2 ft diameter Hydraulic D s lbf ft lbm constant nal Gravitatio g velocity slip non on dependent factor ess Dimensionl R s ft velocity liquid l Superficia V ft lb density Liquid factor friction phase Two f length of foot per ft lb drop Pressure P where c L sL L tp = ÷ ÷ = ÷ = = = ÷ = = A If the ratio of superficial gas velocity to the non-slip velocity is greater than the bubble flow number, and the gas velocity number is smaller than the slug flow number, then slug flow exists. The pressure drop in this case is: ( ¸ ( ¸ I + | | . | \ | + + | | . | \ | = A r ns r sL c ns L tp V V V V D g V f P 2 ρ 2 9.15 Constant velocity rise Bubble V velocity slip Non V where r ns = I = ÷ = : The pressure drop calculation for mist flow is as follows: ( ) D g V f P c sg g tp 2 ρ 2 = A 164 9 Theoretical Basis 9.16 ) / ( ρ ) / ( : 3 ft lb density Gas s ft velocity gas l Superficia V where g sg = = The pressure drop for transition flow is: ( ) m s P x P P A ÷ + A = A 1 9.17 numbers velocity gas and flow slug flow mist on dependent factor Weighting x flow mixed for drop Pressure Pm flow slug for drop Pressure Ps where , , , : = = A = A The pressure drop calculated by the previous equations, are for a one-foot length of pipe. These are converted to total pressure drop by: ( ( ¸ ( ¸ | | . | \ | ÷ A = A 2 4637 1 144 ρ p f total total PA G Q PL P 9.18 ) ( ) ( ) ( ) ( ) / ( ) / ( / ) / ( ρ : 2 3 3 ft segment line of Length L above calculated as drop pressure Unit P psia segment in pressure Average p ft pipe of area sectional Cross A s ft rate flow Gas G s lb gas liquid combined of rate Mass Q ft lb regime flowing the of Density where p f total = = A = ÷ = = = = 9 Theoretical Basis 165 Fittings Pressure Change Methods The correlations used for the calculation of the pressure change across a fitting are expressed using either the change in static pressure or the change in total pressure. Static pressure and total pressure are related by the relationship: 2 ρ 2 v P P s t + = 9.19 In this equation and all subsequent equations, the subscript t refers to total pressure and the subscript s refers to the static pressure. Enlargers/Contractions The pressure change across an enlargement or contraction may be calculated using either incompressible or compressible methods. For two phase systems a correction factor that takes into account the effect of slip between the phases may be applied. Figure A.2 and A.3 define the configurations for enlargements and contractions. In these figures the subscript 1 always refers to the fitting inlet and subscript 2 always refers to the fitting outlet. Fig 9.2 Fig 9.3 166 9 Theoretical Basis Fitting Friction Loss Coefficient The friction loss coefficients for Enlargements & Contractions are given by: Sudden and Gradual Enlargement For an enlarger, both Crane & HTFS methods use the same the fittings loss coefficients which are defined by Crane 26 . These methods are based on the ratio of smaller diameter to larger diameter (β). If u < 45° ( ) 2 2 1 β 1 2 θ sin 6 . 2 ÷ | . | \ | = K 9.20 Otherwise ( ) 2 2 1 β 1÷ = K 9.21 2 1 β diameter larger o diameter t smaller of ratio the is β where, d d = Sudden and Gradual Contraction For a contraction the fittings loss coefficient in Crane & HTFS methods are calculated differently for abrupt sudden contractions. Otherwise the coefficients are same for Crane & HTFS methods. These calculation methods are as described below: Crane The fitting loss coefficient is calculated as per HTFS 27 . These methods are based on the ratio of smaller diameter to larger diameter (β). 2 1 σ c t C K K = 9.22 57806 . 0 0.39543σ σ 5385 . 4 σ 24265 . 14 σ 54038 . 8 σ 2211 . 19 0.5 1.5 2.5 2 + + ÷ + + ÷ = t K 9.23 2 1 2 σ | | . | \ | = d d where: 9 Theoretical Basis 167 The contraction coefficient, is defined by ( ) ( ) ( ) 25 . 0 79028 . 4 θ' 6240 . 9 θ' 1 θ' 03614 . 0 0179 . 0 + + = ÷ le C c 9.24 o θ/180 θ' : = where HTFS The fittings loss coefficients are defined by HTFS 27 . These methods are same as the previous Crane method (Equations A.22 – A.24) except for sudden contractions where the contraction coefficient is calculated differently. If θ = 180 ° (Abrupt contraction) ( ) σ - 1 0.41 1 1 + = c C 9.25 Incompressible Single Phase Flow The total pressure change across the fitting is given by: 2 ρ 2 1 1 1 v K P t = A 9.26 Velocity v density Mass t coefficien loss Fittings K change pressure Total p where = = = = A ρ : 1 Incompressible Two Phase Flow Sudden and Gradual Enlargement The static pressure change across the fitting is given by HTFS 27 2 2 1 2 1 2ρ σ 1 1 LO l s m K P |  | . | \ | + ÷ = A 9.27 ( ) g g g l g g LO x x ε - 1 1 ρ ρ ε 2 2 2 ÷ + = | 168 9 Theoretical Basis 9.28 t coefficien loss Fittings K fraction mass Phase x fraction void Phase density mass Phase flux Mass m where = = = = = 1 ε ρ : Sudden and Gradual Contraction The static pressure change across the fitting is given by HTFS 27 ( ) 2 2 2 2 2ρ σ 1 LO l t s m K P |  ÷ + = A 9.29 ( ) 2 2 2 1 g L LO x ÷ =| | 9.30 2 2 1 1 X X C L + + = | 9.31 5 . 0 ρ ρ 1 | | . | \ | | | . | \ | ÷ = l g g g x x X 9.32 5 . 0 5 . 0 ρ ρ ρ ρ | | . | \ | + | | . | \ | = l g g l C 9.33 t coefficien loss Fittings K fraction mass Phase x fraction void Phase density mass Phase flux Mass m where = = = = = 1 ε ρ : 9 Theoretical Basis 169 Compressible Single Phase Flow Sudden and Gradual Enlargement The static pressure change across the fitting is given by HTFS 27 | | . | \ | ÷ = A 1 σ ρ ρ σ ρ 2 1 1 2 1 m P s  9.34 density mass Phase flux Mass m where = = ρ : Sudden and Gradual Contraction The static pressure change across the fitting is calculated using the two-phase method given in Compressible Two Phase Flow below. The single-phase properties are used in place of the two-phase properties. Compressible Two Phase Flow Sudden and Gradual Enlargement The static pressure change across the fitting is given by HTFS 27 | . | \ | ÷ = A 1 2 2 1 σ σ E E s v v m P  9.35 by given volume specific Equivalent v where E = : ( ) ( ) ( ) ( ) ( ( ( ( ( ¸ ( ¸ ¦ ¦ ) ¦ ¦ ` ¹ ¦ ¦ ¹ ¦ ¦ ´ ¦ ÷ | | . | \ | ÷ + ÷ + ÷ + = 1 1 1 1 1 5 . 0 2 l g R R g g l g R g g E v v u u x x v x u v x v 9.36 5 . 0 | | . | \ | = l H R v v u 9.37 ( ) l g g g H v x v x v ÷ + = 1 170 9 Theoretical Basis 9.38 fraction mass Phase x density mass Phase flux Mass m where = = = ρ : Sudden and Gradual Contraction The pressure loss comprises two components. These are the contraction of the fluid as is passed from the inlet to the vena contracta plus the expansion of the fluid as it passes from the vena contracta to the outlet. In the following equations the subscript t refers to the condition at the vena contracta. For the flow from the inlet to the vena conracta, the pressure change is modeled in accordance with HTFS 27 by: ( ) ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | | . | \ | ÷ = } 2 2 1 1 1 2 1 ζ 1 1 σ 1 1 2 ζ c E Et E E E C v v P v m d v v  9.39 1 ζ P P = 9.40 For the flow from the vena contracta to the outlet the pressure change is modeled used the methods for Sudden and Gradual Expansion given above. Tees Tees can be modeled either by using a flow independent loss coefficient for each flow path or by using variable loss coefficients that are a function of the volumetric flow and area for each flow path as well as the branch angle. The following numbering scheme is used to reference the flow paths. Fig 9.4 Constant Loss Coefficients The following static pressure loss coefficients values are suggested by the API 23 : 9 Theoretical Basis 171 θ 13 K 23 K 12 K 31 K 32 K 21 K <90o 0.76 0.50 1.37 0.76 0.50 1.37 90o 1.37 0.38 1.37 1.37 0.38 1.37 The selection of the coefficient value is dependent on the angle and the direction of flow through the tee. For flow into the run, the loss coefficient for tee is: θ 13 K 12 K 90o 0.38 1.37 <>90o 0.50 1.37 For flow into the branch, the loss coefficient for tee is: θ 21 K 23 K 90o 1.37 1.37 <>90o 1.37 0.76 For flow into the tail, the loss coefficient for tee is: θ 31 K 23 K 90o 0.38 1.37 <>90o 0.50 0.76 4 . 3 2 , 1 : A Figure in shown as assigned are and numbers Reference where The static pressure change across the fitting is given by: 2 ρ 2 v K P s = A 9.41 Variable Loss Coefficients The loss coefficients are a function of the branch angle, branch area to total flow area ratio and branch volumetric flow to total volumetric flow ratio. These coefficients can be determined either from graphical representation by Miller 25 or from the Gardel 28 equations. Using these methods, static pressure changes can be calculated from: Combining Flow 2 ρ 2 ρ 2 ρ 2 2 3 3 2 3 3 1 2 1 1 13 v P v P v K ( ( ¸ ( ¸ | | . | \ | + ÷ | | . | \ | + = 172 9 Theoretical Basis 9.42 2 ρ 2 ρ 2 ρ 2 2 3 3 2 3 3 2 2 2 2 23 v P v P v K ( ¸ ( ¸ | | . | \ | + ÷ | | . | \ | + = 9.43 Dividing Flow 2 ρ 2 ρ 2 ρ 2 2 3 1 2 1 1 3 2 3 3 31 v P v P v K ( ¸ ( ¸ | | . | \ | + ÷ | | . | \ | + = 9.44 2 ρ 2 ρ 2 ρ 2 2 3 2 2 2 2 3 2 3 3 32 v P v P v K ( ( ¸ ( ¸ | | . | \ | + ÷ | | . | \ | + = 9.45 Miller Method A typical Miller chart for 23 K in combining flow is shown. Fig 9.5 Gardel Method 9 Theoretical Basis 173 These coefficients can also be calculated analytically from the Gardel 28 Equations given below: - Combining flow: ( ) ( ) ( ) ( ) ( ) r r r r q q q q K ÷ ÷ + ( ¸ ( ¸ ÷ ÷ | | . | \ | ÷ + | | . | \ | ÷ ÷ ÷ ÷ ÷ = 1 2 cos 1 1 1 8 . 0 1 cos 2 . 1 1 92 . 0 2 2 2 13 ¢ ¢ u ¢ ¢ ¢ o µ ( ) ( ) ( ) ( ) ( ) r r r r q q q q K ÷ ÷ + ( ¸ ( ¸ ÷ ÷ | | . | \ | ÷ ÷ + ÷ ÷ = 1 2 1 38 . 0 1 cos 62 . 1 1 1 03 . 0 2 2 23 ¢ ¢ ¢ u µ 9.46 - Dividing Flow ( ) ( ) ( ) ( ) r r r r q q q q K ÷ | | . | \ | + + ( ( ¸ ( ¸ | | . | \ | ÷ | | . | \ | ÷ + ÷ + ÷ = 1 2 tan 1 1 4 . 0 9 . 0 1 1 . 0 4 . 0 3 . 0 2 tan 3 . 1 1 95 . 0 2 2 2 31 u ¢ ¢ µ ¢ ¢ u ( ) ( ) r r r r q q q q K ÷ ÷ + ÷ = 1 2 . 0 35 . 0 1 03 . 0 2 2 32 9.47 Where, q r = Ratio of volumetric flow rate in branch to total volumetric flow rate Φ = Area ratio of pipe connected with the branch to the pipe carrying the total flow ρ = Ratio of the fillet radius of the branch to the radius of the pipe connected with the branch θ = Angle between branch and main flow as shown in Fig 9.4 Orifice Plates Orifice plates can be modeled either as a sudden contraction from the inlet pipe size to the orifice diameter followed by a sudden expansion from the orifice diameter to the outlet pipe size or by using the HTFS equation for a thin orifice plate. ( ) 1 2 1 β 5082 . 1 2 4 ρ 2 β 1 β 2.825 0.08956 m P s  ÷ = A 9.48 See Incompressible Single Phase Flow on Page 263 for a definition of the symbols. 174 9 Theoretical Basis Vertical Separators The Pressure change across the separator comprises the following components: Expansion of the multiphase inlet from the inlet diameter, d 1 , to the body diameter d body . Contraction of vapor phase outlet from the body diameter, d body , to the outlet diameter, d 2 Friction losses are ignored. Fig 9.6 Horizontal Separators The Pressure change across the separator comprises the following components calculated using the methods described in Incompressible Single Phase Flow on Page 263: Expansion of the multiphase inlet from the inlet diameter, d 1 , to the vapor space characterized by equivalent diameter of the vapor area. Contraction of vapor phase outlet from the vapor space characterized by the equivalent diameter of the vapor area, to the outlet diameter, d 2 Friction losses are ignored. Fig 9.7 9 Theoretical Basis 175 Vapor-Liquid Equilibrium Compressible Gas The PVT relationship is expressed as: ZRT PV = 9.49 e Temperatur T constant Gas R factor ility Compressib Z Volume V Pressure P where = = = = = : The compressibility factor Z is a function of reduced temperature and pressure. The overall critical temperature and pressure are determined using applicable mixing rules. Vapor Pressure The following equations are used for estimating the vapor pressure, given the component critical properties 3 : ( ) ( ) ( ) ( ) 1 * 0 * * In ω In In r r r p p p + = 9.50 ( ) ( ) 6 0 * 169347 . 0 In 28862 . 1 09648 . 6 92714 . 5 In r r r r T T T p + ÷ ÷ = 176 9 Theoretical Basis 9.51 ( ) ( ) 6 1 * 43577 . 0 In 4721 . 13 6875 . 16 2518 . 15 In r r r r T T T p + ÷ ÷ = 9.52 ) ( ) ( ) / ( ω ) ( ) ( ) / ( : * * * R e temperatur Critical T R e Temperatur T T T e temperatur Reduced T factor Acentric abs psi pressure Critical p abs psi pressure Vapour p p p pressure vapour Reduced p where o c o c r c c r = = = = = = = This equation is restricted to reduced temperatures greater than 0.30, and should not be used below the freezing point. Its use was intended for hydrocarbons, but it generally works well with water. Soave Redlich Kwong It was noted by Wilson (1965, 1966) that the main drawback of the Redlich- Kwong equation of state was its inability of accurately reproducing the vapor pressures of pure component constituents of a given mixture. He proposed a modification to the RK equation of state using the acentricity as a correlating parameter, but this approach was widely ignored until 1972, when Soave (1972) proposed a modification of the SRK equation of this form: ( ) ( ) b V V T T a b V RT P c + ÷ ÷ = ω , , 9.53 The a term was fitted in such a way as to reproduce the vapor pressure of hydrocarbons using the acentric factor as a correlating parameter. This led to the following development: ( ) b V V a b V RT P c + ÷ ÷ = α 9.54 ( ) RK 2 2 as same the P T R a a c c a c O O = 9 Theoretical Basis 177 9.55 ( ) 5 . 0 1 1 α r T S ÷ + = 9.56 2 0.176ω - ω 574 . 1 480 . 0 + = S 9.57 The reduced form is: ( ) 2599 . 0 3.8473α 2559 . 0 3 + ÷ ÷ = r r r r r V V V T P 9.58 The SRK equation of state can represent with good accuracy the behavior of hydrocarbon systems for separation operations, and since it is readily converted into computer code, its usage has been extensive in the last twenty years. Other derived thermodynamic properties, like enthalpies and entropies, are reasonably accurate for engineering work, and the SRK equation enjoys wide acceptance in the engineering community today. Peng Robinson Peng and Robinson (1976) noted that although the SRK was an improvement over the RK equation for VLE calculations, the densities for the liquid phase were still in considerable disagreement with experimental values due to a universal critical compressibility factor of 0.3333, which was still too high. They proposed a modification to the RK equation which reduced the critical compressibility to about 0.307, and which would also represent the VLE of natural gas systems accurately. This improved equation is represented by: ( ) ( ) b V b b V V a b V RT P c ÷ + + ÷ ÷ = α 9.59 c c c P T R a 2 2 45724 . 0 = 9.60 c c P RT b 07780 . 0 = 9.61 They used the same functional dependency for the o term as Soave: 178 9 Theoretical Basis ( ) 5 . 0 1 1 α r T S ÷ + = 9.62 2 0.26992ω - ω 5422 . 1 37464 . 0 + = S 9.63 0642 . 0 5068 . 0 4.8514α 2534 . 0 2573 . 3 2 ÷ + ÷ ÷ = r r r r r V V V T P 9.64 The accuracy of the SRK and PR equations of state are roughly the same (except for density calculations). Physical Properties Vapor Density Vapor density is calculated using the compressibility factor calculated from the Berthalot equation 5 . This equation correlates the compressibility factor to the pseudo reduced pressure and pseudo reduced temperature. ) ` ¹ ¹ ´ ¦ | | . | \ | ÷ + = 2 0 . 6 0 . 1 0703 . 0 0 . 1 r r r T T P Z 9.65 ZRT PM = ρ 9.66 Liquid Density Saturated liquid volumes are obtained using a corresponding states equation developed by R. W. Hankinson and G. H. Thompson 14 which explicitly relates the liquid volume of a pure component to its reduced temperature and a second parameter termed the characteristic volume. This method has been adopted as an API standard. The pure compound parameters needed in the corresponding states liquid density (COSTALD) calculations are taken from the original tables published by Hankinson and Thompson, and the API data book for components contained in Aspen Flare System Analyzer's library. The parameters for hypothetical components are based on the API gravity and the generalized Lu equation. Although the COSTALD method was developed for saturated liquid densities, it can be applied to sub-cooled liquid densities, i.e., 9 Theoretical Basis 179 at pressures greater than the vapor pressure, using the Chueh and Prausnitz correction factor for compressed fluids. The COSTALD model was modified to improve its accuracy to predict the density for all systems whose pseudo- reduced temperature is below 1.0. Above this temperature, the equation of state compressibility factor is used to calculate the liquid density. Vapor Viscosity Vapor viscosity is calculated from the Golubev 3 method. These equations correlate the vapor viscosity to molecular weight, temperature and the pseudo critical properties. Tr > 1.0 167 . 0 ) / 29 . 0 71 . 0 ( 667 . 0 5 . 0 0 . 10000 5 . 3 μ c T r c T T P M r + = 9.67 Tr ≤ 1.0 167 . 0 ) 965 . 0 ( 667 . 0 5 . 0 0 . 10000 5 . 3 μ c r c T T P M = 9.68 Liquid Viscosity Aspen Flare System Analyzer will automatically select the model best suited for predicting the phase viscosities of the system under study. The model selected will be from one of the three available in Aspen Flare System Analyzer: a modification of the NBS method (Ely and Hanley), Twu's model, and a modification of the Letsou-Stiel correlation. Aspen Flare System Analyzer will select the appropriate model using the following criteria: Chemical System Liquid Phase Methodology Lt Hydrocarbons (NBP < 155 F) Mod Ely & Hanley Hvy Hydrocarbons (NBP > 155 F) Twu Non-Ideal Chemicals Mod Letsou-Stiel All the models are based on corresponding states principles and have been modified for more reliable application. These models were selected since they were found from internal validation to yield the most reliable results for the chemical systems shown. Viscosity predictions for light hydrocarbon liquid phases and vapor phases were found to be handled more reliably by an in- house modification of the original Ely and Hanley model, heavier hydrocarbon liquids were more effectively handled by Twu's model, and chemical systems were more accurately handled by an in-house modification of the original Letsou-Stiel model. 180 9 Theoretical Basis A complete description of the original corresponding states (NBS) model used for viscosity predictions is presented by Ely and Hanley in their NBS publication 16 . The original model has been modified to eliminate the iterative procedure for calculating the system shape factors. The generalized Leech- Leland shape factor models have been replaced by component specific models. Aspen Flare System Analyzer constructs a PVT map for each component and regresses the shape factor constants such that the PVT map can be reproduced using the reference fluid. Note: The PVT map is constructed using the COSTALD for the liquid region. The shape factor constants for all the library components have already been regressed and are stored with the pure component properties. Pseudo component shape factor constants are regressed when the physical properties are supplied. Kinematic or dynamic viscosity versus temperature curves may be supplied to replace Aspen Flare System Analyzer's internal pure component viscosity correlations. Aspen Flare System Analyzer uses the viscosity curves, whether supplied or internally calculated, with the physical properties to generate a PVT map and regress the shape factor constants. Pure component data is not required, but if it is available it will increase the accuracy of the calculation. The general model employs methane as a reference fluid and is applicable to the entire range of non-polar fluid mixtures in the hydrocarbon industry. Accuracy for highly aromatic or naphthenic oil will be increased by supplying viscosity curves when available, since the pure component property generators were developed for average crude oils. The model also handles water and acid gases as well as quantum gases. Although the modified NBS model handles these systems very well, the Twu method was found to do a better job of predicting the viscosities of heavier hydrocarbon liquids. The Twu model1 8 is also based on corresponding states principles, but has implemented a viscosity correlation for n-alkanes as its reference fluid instead of methane. A complete description of this model is given in the paper 18 titled "Internally Consistent Correlation for Predicting Liquid Viscosities of Petroleum Fractions". For chemical systems the modified NBS model of Ely and Hanley is used for predicting vapor phase viscosities, whereas a modified form of the Letsou- Stiel model 15 is used for predicting the liquid viscosities. This method is also based on corresponding states principles and was found to perform satisfactorily for the components tested. The parameters supplied for all Aspen Flare System Analyzer pure library components have been fit to match existing viscosity data over a broad operating range. Although this will yield good viscosity predictions as an average over the entire range, improved accuracy over a more narrow operating range can be achieved by supplying viscosity curves for any given component. This may be achieved either by modifying an existing library component through Aspen Flare System Analyzer's component librarian or by entering the desired component as a hypothetical and supplying its viscosity curve. 9 Theoretical Basis 181 Liquid Phase Mixing Rules for Viscosity The estimates of the apparent liquid phase viscosity of immiscible Hydrocarbon Liquid - Aqueous mixtures are calculated using the following "mixing rules": If the volume fraction of the hydrocarbon phase is greater than or equal to 0.33, the following equation is used 19 : ( ) oil v oil eff e ÷ = 1 6 . 3 μ μ 9.69 phase n Hydrocarbo fraction Volume v phase n Hydrocarbo of Viscosity viscosity Apparent where oil oil eff = = = μ μ : If the volume fraction of the hydrocarbon phase is less than 0.33, the following equation is used 20 : O H O H oil O H oil oil eff v 2 2 2 μ μ μ μ 4 . 0 μ 5 . 2 1 μ ( ( ¸ ( ¸ | | . | \ | + + + = 9.70 phase n Hydrocarbo fraction Volume v phase Aqueous of Viscosity phase n Hydrocarbo of Viscosity viscosity Apparent where oil O H oil eff = = = = 2 μ μ μ : The remaining properties of the pseudo phase are calculated as follows: ¿ = ) ( weight molecular mw x mw i i eff 9.71 ( ) ( ) ) ( / / 1 ρ density mixture p x i i eff ¿ = 9.72 ¿ = ) ( heat specific misture Cp x Cp i i eff 182 9 Theoretical Basis 9.73 Thermal Conductivity As in viscosity predictions, a number of different models and component specific correlations are implemented for prediction of liquid and vapor phase thermal conductivities. The text by Reid, Prausnitz and Polings 15 was used as a general guideline in determining which model was best suited for each class of components. For hydrocarbon systems the corresponding states method proposed by Ely and Hanley 16 is generally used. The method requires molecular weight, acentric factor and ideal heat capacity for each component. These parameters are tabulated for all library components and may either be input or calculated for hypothetical components. It is recommended that all of these parameters be supplied for non-hydrocarbon hypotheticals to ensure reliable thermal conductivity coefficients and enthalpy departures. The modifications to the method are identical to those for the viscosity calculations. Shape factors calculated in the viscosity routines are used directly in the thermal conductivity equations. The accuracy of the method will depend on the consistency of the original PVT map. The Sato-Reidel method 15 is used for liquid phase thermal conductivity predictions of glycols and acids, the Latini et al. Method 15 is used for esters, alcohols and light hydrocarbons in the range of C3 - C7, and the Missenard and Reidel method 15 is used for the remaining components. For vapor phase thermal conductivity predictions, the Misic and Thodos, and Chung et al. 15 methods are used. The effect of higher pressure on thermal conductivities is taken into account by the Chung et al. method. As in viscosity, the thermal conductivity for two liquid phases is approximated by using empirical mixing rules for generating a single pseudo liquid phase property. Enthalpy Ideal Gas The ideal gas enthalpy is calculated from the following equation: 4 3 2 T E T D T C T B A H i i i i i ideal + + + + = 9.74 terms capacity heat gas Ideal E D C B A e Temperatur T enthalpy Ideal H where = = = , , , , : 9 Theoretical Basis 183 Lee-Kesler The Lee-Kesler enthalpy method corrects the ideal gas enthalpy for temperature and pressure. dep ideal H H H + = 9.75 ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | | . | \ | ÷ | | . | \ | + | | . | \ | = | | . | \ | s c dep r c dep r s c dep c dep RT H RT H RT H RT H ω ω 9.76 ¦ ¦ ) ¦ ¦ ` ¹ ¦ ¦ ¹ ¦ ¦ ´ ¦ + + | | . | \ | ÷ ÷ | | . | \ | + | | . | \ | ÷ ÷ ÷ ÷ = | | . | \ | E V T d V T T c c V T T b T b b Z T RT H r r k r r r k k r r t k r k k k r k c dep 3 5 2 3 3 2 0 . 1 5 2 2 2 3 2 2 4 3 2 9.77 ¦ ) ¦ ` ¹ ¦ ¹ ¦ ´ ¦ | | . | \ | + + ÷ + = 2 γ 2 3 4 γ 1 β 0 . 1 β γ 2 r k V r k k k k r k e V T c E 9.78 enthalpy departure gas Ideal H terms Kesler Lee d c b enthalpy Ideal H fluid Simple s fluid Reference r factor Acentric enthalpy Specific H e temperatur Critical T where dep ideal c = ÷ = = = = = = = γ β, , , , ω : Equations of State The Enthalpy and Entropy calculations are performed rigorously using the following exact thermodynamic relations: dV P T P T RT Z RT H H V V ID } · ( ¸ ( ¸ ÷ | . | \ | c c + ÷ = ÷ 1 1 184 9 Theoretical Basis 9.79 dV V T P R P P Z R S S V V o ID o } · ( ¸ ( ¸ ÷ | . | \ | c c + ÷ = ÷ 1 1 In In 9.80 For the Peng Robinson Equation of State, we have: ( ) ( ) | | . | \ | ÷ + + + ( ¸ ( ¸ ÷ ÷ ÷ = ÷ b V b V dt da T a bRT Z RT H H ID 1 2 1 2 In 2 1 1 5 . 0 5 . 0 5 . 1 9.81 ( ) ( ) ( ) ( ¸ ( ¸ ÷ ÷ + + | . | \ | + ÷ ÷ = ÷ B Z B Z adT Tda B A P P B Z R S S o ID o 1 2 1 2 In 2 In In 5 . 0 5 . 0 5 . 1 9.82 ( ) ( ) ij j i N i N j j i k a a x x a where ÷ = ¿¿ = = 1 : 5 . 0 1 1 9.83 For the SRK Equation of State: | . | \ | + ( ¸ ( ¸ ÷ ÷ ÷ = ÷ V b dt da T a bRT Z RT H H ID 1 In 1 1 9.84 ( ) | . | \ | + | . | \ | + ÷ ÷ = ÷ Z B adT Tda B A P P B Z R S S o ID o 1 In In In 9.85 A and B term definitions are provided below: Term Peng-Robinson Soave-Redlich-Kwong i b ci ci P RT 077796 . 0 ci ci P RT 08664 . 0 i a i ci a α i ci a α 9 Theoretical Basis 185 Term Peng-Robinson Soave-Redlich-Kwong ci a ( ) ci ci P RT 2 457235 . 0 ( ) ci ci P RT 2 42748 . 0 i α ( ) 5 . 0 1 1 ri i T m ÷ + ( ) 5 . 0 1 1 ri i T m ÷ + i m 2 ω 26992 . 0 ω 54226 . 1 37646 . 0 i i ÷ + 2 ω 176 . 0 ω 57 . 1 48 . 0 i i ÷ + ( ) ( ) ij j i N i N j j i k a a x x a where ÷ = ¿¿ = = 1 : 5 . 0 1 1 9.86 ¿ = = N i i i b x b and 1 9.87 Entropy S Enthalpy H constant gas Ideal R state Reference gas Ideal ID o = = = = = 186 9 Theoretical Basis Noise The sound pressure level at a given distance from the pipe is calculated from the following equations. In these equations the noise producing mechanism is assumed to be solely due to the pressure drop due to friction. | | . | \ | | . | \ | A = 4 π 36 . 1 2 | L P W m v 9.88 t r L W SPL m r ÷ | | . | \ | = 2 13 π 4 η 10 log 10 9.89 velocity fluid Average v loss on transmissi wall Pipe t pressure in Change P efficiency Acoustic diameter Internal pipe from Distance r level pressure Sound SPL length Equivalent L where = = = A = = = = = η : | 9 Theoretical Basis 187 Fig 9.8 The transmission loss due to the pipe wall is calculated from: 0 . 36 5 . 0 0 . 17 ÷ | | . | \ | = | mv t 9.90 velocity fluid Average v diameter Internal area unit per mass wall Pipe m where = = = | : The acoustical efficiency is calculated from the equation below. ( ) 5388 . 9 ln * 9986 . 4 exp ÷ = M P r q 9.91 where Pr = Ratio of higher absolute Pr over lower absolute Pr between two ends of the pipe (i.e. if upstream pr.> downstream pr., Pr = upstream pr./downstream pr. Else if upstream pr.< downstream pr., Pr = downstream pr./upstream pr.) M = Mach No. 0.0 0.2 0.4 0.6 0. 8 1.0 Mach Num ber 10 - 11 10 - 10 10 - 9 10 - 8 10 - 7 10 - 6 10 -5 10 - 4 10 - 3 A c o u s t i c a l E f f i c i e n c y pt = 10.0 pt = 1.0 pt = 0. 1 188 9 Theoretical Basis A File Format 189 A File Format Import/Export Details This section provides further details of the import and export capabilities of Aspen Flare System Analyzer. Important! The definition format for Import/Export has changed since Aspen Flare System Analyzer V7.3. As a result, if you are using Aspen Flare System Analyzer V7.3 or later, you cannot import files generated from Aspen Flare System Analyzer V7.2 and earlier versions or export on top of a file that has been generated using Aspen Flare System Analyzer V7.2 or earlier versions. Process Descriptions Import Wizard The purpose of this section of the documentation is to describe step by step the operation of the import wizard. End of Step 1 At this stage the import process verifies that the specified import file exists and opens it. The import wizard is then configured for the appropriate file type. Any errors are reported. End of Step 2 At this stage the import process opens the specified import definition file or the default or new import definition file as specified in Preferences as appropriate. A check is made that the import definition file type matches the file type specified in step 1. The version of the import definition file is then checked; data object and data item elements are added to update to the current Aspen Flare System Analyzer version if required. The next step is to process the file to build the object selector tree view for Step 3. Any problems in reading the import definition file are reported. 190 A File Format Step 3 During this step, the Import Wizard extracts Source tab data and Field Details for each data item as different data objects are selected. Whenever a new data object is selected, the data on the Source tab is validated and any problems are reported. End of Step 4 The first action taken is to save the import definition file if required, prompting for the file name to be used. The import process then begins. In detail, the steps are: 1 Clear current results. 2 Open log file if required. 3 Read components one by one. For each component check to see if it already exists in the current Aspen Flare System Analyzer case. If not, add the component to list. For database components, use information from database; otherwise, use the data values from file. 4 Read binary interaction parameter data. 5 Read data for pipes, connector nodes and source nodes one object type at a time; updating the progress view as appropriate. 6 As each instance of a particular object type is read, check if it already exists. If so, use the data read to update it; otherwise, create a new instance of the appropriate object type. 7 Make connections between pipes and nodes. Processing allows for only one end of the connection to be read. 8 Read scenario data. Existing scenarios will be updated, and new ones created if required. 9 Read Solver options. 10 Update automatic calculations to reflect new data values. 11 Refresh all views. 12 Close log file, and then close Import Data File. Any background copy of Excel will be closed at this point. 13 Close the Import Wizard and finish. General Data Object Import Procedure For each object type that is read, the detailed import procedure is as follows: 1 Check to see if import of this object type is required. Quit reading this type of data object if not. 2 Process the data object definition data from the Import Definition File. Search for and open the specified source object. Quit if any errors are encountered. 3 Search the source data object for an instance of the appropriate object type using the defined select criteria if required. For Access imports, this will be a row in the specified table; for Excel imports, this will be a row or column range in the specified worksheet where cell offset 1,1 is not blank; for XML imports, this will be an item element within the specified group element. 4 Repeat steps 2 and 3 to open any sub section data objects. A File Format 191 5 Read data items from source one by one. 6 Update counters for number of instances read and search data source for next object instance. For an Access imports, this will be the next row; for Excel imports, the next row or column range; for XML imports, the next item element. Selection criteria will apply if specified. Quit if the next instance cannot be found. 7 Repeat steps 5 and 6 until all instances have been read. Export Process The purpose of this section of the documentation is to describe step by step the operation of the export wizard. End of Step 1 At this stage the export process checks to see if the target export file exists. If so, it opens the file; otherwise, a new file with the defined name is created. The Export Wizard is then configured for the appropriate file type. Any errors are reported. End of Step 2 At this stage, the export process opens the specified export definition file or the default or new export definition file specified in Preferences as appropriate. A check is made that the export definition file type matches the file type specified in step 1. The version of the export definition file is then checked and data object and data item elements are added to update it to the current Aspen Flare System Analyzer version if required. The next step is to process the file to build the object selector tree view for Step 3. Any problems in reading the export definition file are reported. Step 3 During this step, the Export Wizard extracts Target tab data and Field Details for each data item as different data objects are selected. Whenever a new data object is selected, the data on the Target tab is validated and any problems are reported. End of Step 4 The first action taken is to save the export definition file if required, prompting for the file name to be used. The export process then begins. In detail the steps are: 1 Clear existing data from export file if requested. 2 Write components data. 3 Write binary interaction parameter data. 4 Write pipe data. 5 Write connector node and source node data, working through each type of node in turn. 6 Write scenario data for scenarios that are selected for calculation. 192 A File Format 7 Write results data for scenarios that are selected for calculation. 8 Write solver options. 9 Save export file. Any background copy of Excel will be closed at this point. 10 Close the Export Wizard. General Data Object Export Procedure For each object type that is written, the detailed export procedure is as follows: 1 Check that export of this data object type is required. Quit if not. 2 Create target data object using information from export definition file. For Access export, this will create a table with the correct fields; for Excel export, a worksheet with the correct name; for XML export, a group tag with the correct name. Quit if any errors are encountered. 3 Create target data objects as required for any data subsections. 4 For each instance of the data object to be written, search the output file to see if this instance already exists. If so, select this to be overwritten; otherwise, create a new instance for the data object in the output file. For Access export, this will be a new row in that target table; for Excel export, the next row or column range where cell offset 1,1 is blank; for XML export, a new item element. Quit if the new target instance cannot be found. 5 Write the values to the target object instance. 6 Update counters for number of items read and mark target instance as complete. 7 Repeat steps 4 to 6 until each instance of this data object has been written. Definition File Formats The import and export definition files are XML formatted data files that describe how the various Aspen Flare System Analyzer data objects and their corresponding data items should be read from or written to the supported external file formats. This section of the documentation describes the layout of these files. Import File Formats File Header The top level element of an import definition file must have the tag name FlarenetImport and contain the following attributes: Attribute Description LastModified This is a date string that indicates the date that the file was last updated. FlarenetVersion This indicates the version of Aspen Flare System Analyzer that the file is applicable to. FileType This indicates the type of external file import that is described in this definition file. Valid values are Access, Excel or XML. A File Format 193 Data Object Elements The child elements of the FlarenetImport tag define the various data objects that may be imported by Aspen Flare System Analyzer. These parent data object elements may contain child data object elements that describe data subsections which may be imported from a different location to the parent data object. For example, a pipe data object has a data subsection defined for the PFD layout information. A data object element has the following attributes: Attribute Description ObjectName This defines the source of the data object in the external file. Its usage depends on the type of external file as follows: - Access – The entry defines a database table. - Excel – The entry defines a worksheet. - XML – The entry defines the tag name of a group element. Import This indicates whether this object type is to be imported. Valid values are Yes or No. Contained This indicates whether the data for this object is contained in the same external data source as the parent object. Valid values are Yes or No. This setting is always No for a parent data object. DataBy This entry appears in Excel import definition files only. It defines how the data for this object is organized. Valid values are Row, Column or Sheet. StartAt This entry appears in Excel import definition files only. When DataBy is set to Row or Column, it defines the starting row or column for the data. When DataBy is set to Sheet, it defines the tag by which worksheets of the requisite layout can be identified. PerItem This entry appears in Excel import definition files only. It defines the number of rows or columns occupied by a single instance of a data object, including any spacing, when DataBy is set to Row or Column. ItemTag This entry appears in XML import definition files only. It defines the element tag name used to identify each instance of a data object within the group tag name defined in the ObjectName attribute. A list of valid Data Object elements names is given in Data Objects List. Data Item Elements Each data object element contains data item elements that define the location of the individual data item in the external data source. A data item element contains the following attributes: Attribute Description Import This indicates whether the item is to be imported. Valid values are Yes or No. 194 A File Format Attribute Description Offset This defines the location of the data value in the external file. Its usage depends on the type of external file, but data substitution codes can be defined for the offset in all cases – see Data Substitution Codes. - Access – The entry defines a field within the database table for the object. - Excel – The entry defines a cell within the worksheet for the object. The cell is defined either by a single row or column offset or by a row, column offset. - XML – The entry defines the tag name of an element within the item tag element for the object. A list of the data item elements that are recognized for each data object is given in Data Items List. Export File Formats File Header The top level element of an export definition file must have the tag name FlarenetExport and contain the following attributes: Attribute Description LastModified This is a date string that indicates the date that the file was last updated. FlarenetVersion This indicates the version of Aspen Flare System Analyzer that the file is applicable to. FileType This indicates the type of external file export that is described in this definition file. Valid values are Access, Excel or XML. Data Object Elements The child elements of the FlarenetExport tag define the various data objects that may be exported by Aspen Flare System Analyzer. These parent data object elements may contain child data object elements that describe data subsections which may be exported to a different location to the parent data object. A data object element has the following attributes: Attribute Description ObjectName This defines the name of the data object that will be created and written to in the external file. Its usage depends on the type of external file as follows: - Access – The entry defines a database table. - Excel – The entry defines a worksheet. - XML – The entry defines the tag name of a group element. Export This indicates whether this object type is to be exported. Valid values are Yes or No. Contained This indicates whether the data for this object is to be written to the same external data source as the parent object. Valid values are Yes or No. This setting is always No for a parent data object. A File Format 195 Attribute Description DataBy This entry appears in Excel export definition files only. It defines how the data for this object is organized. Valid values are Row, Column or Sheet. StartAt This entry appears in Excel export definition files only. When DataBy is set to Row or Column, it defines the starting row or column for the data. When DataBy is set to Sheet, it defines the name of the worksheet that will be copied to create a worksheet for each instance of the data object. This name must begin with a “%” character. PerItem This entry appears in Excel export definition files only. It defines the number of rows or columns occupied by a single instance of a data object, including any spacing, when DataBy is set to Row or Column. ItemTag This entry appears in XML export definition files only. It defines the element tag name used to identify each instance of a data object within the group tag name defined in the ObjectName attribute. A list of valid Data Object elements names is given in Data Objects List. Data Item Elements Each data object element contains data item elements that define how an individual data item is to be written to the external data source. A data item element contains the following attributes: Attribute Description Export This indicates whether the item is to be exported. Valid values are Yes or No. Offset This defines the location where the data value will be written in the external file. Its usage depends on the type of external file, but data substitution codes can be defined for the offset in all cases – see Data Substitution Codes. - Access – The entry defines a field within the database table for the object. - Excel – The entry defines a cell within the worksheet for the object. The cell is defined either by a single row or column offset or by a row, column offset. - XML – The entry defines the tag name of an element within the item tag element for the object. Type This appears in Access export definition files only. It defines the data type of the field to be created for this item. Valid values are Text for text strings, Long for integer values, Double for floating point values. Length This appears in Access export definition files only. It defines the length of the field to be created. For fields of type Text, it defines the length of the text string in characters; for fields of types Long and Double, it is set to 0 and will be ignored though it must be present. A list of the data item elements that are recognized for each data object is given in Data Items List. Data Substitution Codes As indicated in the above data substitution codes may be defined in the Offset attribute for item import and export data items. The details of these codes are as follows: 196 A File Format Offset Codes The following codes are recognized and processed in the Offset attribute in both import and export definition files. “%ObjectName” where ObjectName is the name of a data object element, will be replaced by a value that iterates as successive instances of that type of object are read or written for this instance of the parent data object. It is used to provide a value that iterates through repeated data items, e.g. component data or pipe fitting data. ObjectName may refer to any data object element that is a parent of the data item. The code is usually used in conjunction with a + symbol to add the iteration value to some constant value. In an Access or XML import or export definition file, the + symbol means that the iteration value is concatenated with the constant value. E.g. Frac+%Composition will be expanded to Frac1, Frac2 etc. In an Excel import or export definition file, *, -, and / symbols as well as the + symbol are recognized to combine the iteration value with a constant value to calculate a cell address. E.g. 2,2+%Composition will be expanded to the cell references 2,3 then 2,4 etc. See the CurveMassFlow data item in the TipCurveData data object in the definition file DefExcel.fni for a more complicated example. “#ObjectName” where ObjectName is the name of a data object element, will be replaced by the total number of instances of that type of data object that have been read. ObjectName may refer to any data object element that is a child of the current data object element. The value returned is usually combined with some constant value through a + or other symbols as for the “%ObjectName” code. “?Composition” is a special code that is used exactly as it stands. “?Composition” will be replaced by each component name or offset in turn as successive component composition data items are read or written. It is generally used in conjunction with a + symbol to each component name or offset to some constant value. In an Access or XML import or export definition file, ?Composition will return component names in turn from the master component list. e.g. Frac+?Composition will be evaluated as FracMethane, FracEthane etc. In an Excel import or export definition, ?Composition will return the index number of a component in the master component list to allow it to be used to calculate a cell offset. In both cases, the master component list is the union of the components in the current Aspen Flare System Analyzer case and the import or export definition files. Essentially this code allows unambiguous specification of a component identity when merging of the component lists between a Aspen Flare System Analyzer case and an import or export definition file. A File Format 197 Recognized Objects and Items Data Objects List Data object elements for the following data objects and sub-sections are recognized in import and export definition files. Element Tag Sub Section Data Object Elements Description Components None Component data BIPs None Binary interaction parameters Connectors PFDLayout Connector nodes ControlValves PFDLayout Composition SourceData Control valve source nodes FlowBleeds PFDLayout Flow bleed nodes HorizontalSeparators Composition PFDLayout Horizontal separator nodes OrificePlates PFDLayout Orifice plate nodes Fitting None Fitting data for pipes Pipes PFDLayout Fitting Pipes ReliefValves PFDLayout SourceData Relief valve source nodes Tees PFDLayout Tee nodes FlareTips PFDLayout Curves Flare tip nodes Curves Points Tip pressure drop curves Points None Data points in tip pressure drop curve VerticalSeparators PFDLayout Vertical separator nodes Solvers None Solver options Scenarios SourceData Scenario data Composition None Component composition data SourceData Composition Scenario specific source data PFDLayout None PFD layout information Results Phase Summary results data for each pipe. Export definition files only. Phase CompResults Properties for each phase at each end of each pipe. Export definition files only. CompResults None Composition results for each pipe. Export definition files only. Data Items List The data items that can be read for each data object are as follows: 198 A File Format Components Attribute Description Hypothetical The hypothetical components Name The component name Id The component ID number Type The component type Formula The component formula MolWt The component molecular weight NBP The component normal boiling point (K) StdDensity The component standard density (kg/m 3 ) WatsonK The component Watson K value Pc The component critical pressure (bar a) Tc The component critical temperature (K) Vc The component critical volume (m 3 /kgmole) Vchar The component characteristic volume (m 3 /kgmole) Omega The component acentric factor OmegaSRK The component SRK acentric factor Ha The enthalpy A coefficient (kJ/kgmole) Hb The enthalpy B coefficient (kJ/kgmole/K) Hc The enthalpy C coefficient (kJ/kgmole/K2) Hd The enthalpy C coefficient (kJ/kgmole/K3) He The enthalpy C coefficient (kJ/kgmole/K4) Hf The enthalpy C coefficient (kJ/kgmole/K5) S The entropy coefficient ViscA The viscosity A parameter ViscB The viscosity B parameter HeatOFCombustion The heat of combustion NBPValue The value of normal boiling point PcValue The value of critical pressure TcValue The value of critical temperature BIPs Attribute Description PropPkg The code for the property package: - 0 – Vapor pressure - 1 – Peng Robinson - 2 – Soave Redlich Kwong - 3 – Compressible Gas Comp1 The name of the first component Comp2 The name of the second component Kij12 Value of interaction parameter for comp1 / comp2 Kij21 Value of interaction parameter for comp2 / comp1 A File Format 199 Connectors Attribute Description FittingLossMethod Code for the fitting loss method: 0 = ignored, 1 = calculated IsothermalDPOption Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition CompressibleTransition DP percent of inlet pressure for transition (%) Length Length of the swage (mm) Angle The internal angle of the swage (radians) ChokeMethod Choke flow check MaxConnectionCount Maximum possible connection count DescribeCalculations Describe calculations Name The connector name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end DownstreamConnnection The name of the downstream pipe DownstreamConnnectionAt Code for the downstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count ControlValves Attribute Description DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Ignore Ignore flag KMultiply Fittings loss Ft factor for inlet pipe KOffset Fittings loss offset for inlet pipe FlangeDiameter Internal diameter of flange (mm) ElevationChange The elevation change of the inlet piping (m) Length The length of the inlet piping (m) InternalDiameter The inlet pipe diameter (mm) Schedule The inlet pipe schedule NominalDiameter The inlet pipe nominal diameter Roughness The inlet pipe roughness (mm) Material The code for the inlet pipe material: 0 = Carbon Steel, 1 = Stainless steel Thickness Code for the thickness of the pipe wall UsePipeClass Code for enabling pipe class usage: 0 = No, 1 = Yes Name The control valve name 200 A File Format Attribute Description Location The location text UpstreamConnnection The name of the upstream pipe UpstreamConnnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count FlowBleeds Attribute Description OfftakeMultiplier Flow bleed multiplier OfftakeOffset Bleed flow offset (kg/h) OfftakeMinimum Minimum bleed flow (kg/h) OfftakeMaximum Maximum bleed flow (kg/h) PressureDrop Pressure drop over bleed (bar) DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The flow bleed name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point 0 = upstream end, 1 = downstream end DownstreamConnnection The name of the downstream pipe DownstreamConnnectionAt Code for the downstream pipe connection point 0 = upstream end, 1 = downstream end ConnectedCount Connection count HorizontalSeparators Attribute Description LiquidLevel The liquid level (mm) Diameter The vessel diameter (mm) FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 = Calculated IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition CompressibleTransition DP percent of inlet pressure for transition (%) BodyDimension Code for body area usage: 0 = Full body area, 1 = Partial body area on flow ChokeMethod Choke flow check CannotTear Cannot tear DesignLength Design length Ddrop Ddrop A File Format 201 Attribute Description DrainVol Drain volume Holduptime Holdup time Vsettling V settling IsTear Is tear PresBody Body pressure TempBody Body temperature VelBody Body velocity DenBody Body density DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The horizontal separator name Ignore The ignored flag: 0 = not ignored, 1=ignored Location The location text UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end BranchstreamConnection The name of the branch stream pipe BranchstreamConnectionAt Code for the branch stream pipe connection point: 0 = upstream end, 1 = downstream end DownstreamConnection The name of the downstream pipe DownstreamConnectionAt Code for the downstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count OrificePlates Attribute Description FittingLossMethod Code for pressure loss method: 0 = Ignored, 1 = Thin Plate, 2 = Contraction/Expansion IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition= CompressibleTransition DP percent of inlet pressure for transition (%) DownstreamDiameterRatio Ratio of orifice to downstream diameter UpstreamDiameterRatio Ratio of orifice to upstream diameter Diameter Diameter of orifice (mm) ChokeMethod Choke flow check DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The orifice plate name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe 202 A File Format Attribute Description UpstreamConnectionAt The code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end DownstreamConnnection The name of the downstream pipe DownstreamConnnectionAt The code for the downstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count Pipes Attribute Description LimitReached Reached limit or not TailPipe Code to identify tailpipe: 0 = No, 1 = Yes Sizeable Code for indicating sizeable pipe: 0 = No, 1 = Yes UsePipeClass Code for pipe class usage: 0 = No, 1 = Yes WallThickness Pipe wall thickness (mm) InternalDiameter Pipe internal diameter (mm) Schedule Pipe schedule NominalDiameter Pipe nominal diameter ThermalConductivity Pipe material thermal conductivity (W/m/C) Roughness Pipe absolute roughness (mm) Material Code for pipe material: 0 = Carbon steel, 1 = Stainless steel ElevationChange Pipe elevation change (m) Length Pipe length (m) FittingsLossMultiply Fittings loss Ft factor FittingsLossOffset Fittings loss offset LengthMultiplier Multiplier for pipe length MultipleElementCalculation Code for the multiple element heat transfer calculation: 0 = No, 1 = Yes Emissivity The material fractional emissivity ExternalRadiativeHTC Code for including radiative heat transfer: 0 = No, 1 = Yes HeatTransferEnabled Code to enable heat transfer calculations: 0 = No, 1 = Yes WindVelocity Wind speed (m/s) Temperature Temperature outside pipe (C) InsulationThermalConductivity Insulation thermal conductivity (W/m/C) Thickness Insulation thickness (mm) InsulationName Insulation description Duty Duty (kJ/h) OutletTemperatureSpecification Temperature leaving pipe (C) DampingFactor Damping factor VLEMethod Code for VLE method: 0 = Default, 1 = Compressible Gas, 2 = Peng Robinson, 3 = Soave Redlich Kwong, 4 = Vapor Pressure A File Format 203 Attribute Description StaticHeadContribution Code for the static head contribution: 0 = Include, 1 = Ignore Downhill Recovery, 2 = Ignore FrictionFactorMethod Code for friction factor method: 0 = Default, 1 = Round, 2 = Chen Elements Number of elements for pipe calculation VerticalPipe Code for DP method for vertical pipes: 0 = Default, 1 = Isothermal gas, 2 – Adiabatic gas, 3 = Beggs&Brill, 4 = Dukler, 5 = Orkisewski InclinedPipeMethod Code for DP method for inclined pipes: 0 = Default, 1 = Isothermal gas, 2 – Adiabatic gas, 3 = Beggs&Brill, 4 = Dukler HorizontalPipeMethod Code for DP method for horizontal pipes: 0 = Default, 1 = Isothermal gas, 2 – Adiabatic gas, 3 = Beggs&Brill, 4 = Dukler ExternalMedium Code for the external medium: 0 = Air, 1 = Sea Water RoughnessForFitting Roughness for fitting Klocked K locked Kusing K using CalcStatus Calculation status FittingCount Number of fittings linked to this pipe PhysicalLength Physical length MaxConnectionCount Maximum possible connection count Name Name Ignore The ignored flag: 0 = not ignored, 1=ignored Location The location text DescribeCalculations Describe calculations UpstreamConnection The name of the upstream node UpstreamConnectionAt Code for the upstream node connection point: 0,1,2 depending on upstream node DownstreamConnnection The name of the downstream node DownstreamConnnectionAt Code for the downstream pipe connection point: 0,1,2 depending on downstream node ConnectedCount Connection count Fitting Attribute Description ItemName The name of the fitting ID Description of the fitting KOffset Fitting loss constant KMultiplier Fitting loss Ft factor ReliefValves Attribute Description MAWP Maximum allowable working pressure (bar a) 204 A File Format Attribute Description MechPres Mechanical pressure limit (bar a) ValveType Type code for valve: 0 = Balanced, 1 = Conventional OrificeType Standard type code for orifice ValveArea Area of each valve orifice (mm 2 ) ValveCount Number of valves IsenTropicFlash Isentropic flash DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Ignore Ignore flag KMultiply Fittings loss Ft factor for inlet pipe KOffset Fittings loss offset for inlet pipe FlangeDiameter Internal diameter of flange (mm) ElevationChange The elevation change of the inlet piping (m) Length The length of the inlet piping (m) InternalDiameter The inlet pipe diameter (mm) Schedule The inlet pipe schedule NominalDiameter The inlet pipe nominal diameter Roughness The inlet pipe roughness (mm) Material Code for the inlet pipe material: 0 = Carbon Steel, 1 = Stainless steel Thickness Thickness UsePipeClass Code for enabling pipe class usage: 0 = No, 1 = Yes Name The relief valve name Location The location text UpstreamConnnection The name of the upstream pipe UpstreamConnnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count Tees Attribute Description Body Code for body type: 0 = Run, 1 = Tail, 2 = Branch, 3 = Auto Theta Code for branch angle: 0 = 30 deg, 1 = 45 deg, 2 = 60 deg, 3 = 90 deg ThetaAsReal Theta as real FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 = Simple, 2 = Miller MillerChartExtrapolation Code for Miller chart extrapolation: 0 = None, 1 = Miller Ratio Squared, 2 = Gardel ConnectorIfIncomplete Code to use connector calculation: 0 = No, 1 = Yes IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes A File Format 205 Attribute Description TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition CompressibleTransition DP percent of inlet pressure for transition (%) BodyDimension Code for body area usage: 0 = Full body area, 1 = Partial body area on flow ChokeMethod Choke flow check Orientation Orientation Separate Separate CannotTear Cannot tear DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The tee name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end BranchstreamConnection The name of the branch stream pipe BranchstreamConnectionAt Code for the branch stream pipe connection point: 0 = upstream end, 1 = downstream end DownstreamConnection The name of the downstream pipe DownstreamConnectionAt Code for the downstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count FlareTips Attribute Description Diameter Diameter of flare (mm) CompressibleTransition DP percent of inlet pressure for transition (%) Method Method TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes FittingLossCoefficient Fittings loss coefficient FittingLossCoefficientBasis Code for fittings loss basis: 0 = Total pressure, 1 = static pressure UseCurves Code for curve usage: 0 = No, 1 = Yes NumCurves Number of pressure drop curves FlowExtrapolation Flow extrapolation MolWtExtrapolation Molecular weight extrapolation PressureCorrection Pressure correction RefTemp Reference temperature for curve data (C) Sizeable Code for indicating sizeable pipe 206 A File Format Attribute Description UsePipeClass Code for enabling Pipe Class usage WallThickness Wall thickness InternalDiameter Internal diameter Schedule Pipe schedule NominalDiameter Pipe nominal diameter ThermalConductivity Pipe material thermal conductivity (W/m/C) Roughness Pipe roughness Material Code for the inlet pipe material ChokeMethod Choke flow check DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The flare tip name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count Curves Attribute Description TipName The name of the top (30 chars) MolWt The reference molecular weight for the curve CurveNumPoints The number of points in the curve Points Attribute Description CurveDataPointNo The number of the curve data point MolWt The mole weight of the curve MassFlow The mass flow for the curve data point (kg/h) PresDrop The pressure drop for the curve data point (bar) VerticalSeparators Attribute Description Diameter The vessel diameter (mm) FittingLossMethod Code for fittings loss calculation: 0 = Ignored, 1 = Calculated IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition CompressibleTransition DP percent of inlet pressure for transition (%) A File Format 207 Attribute Description ChokeMethod Choke flow check DesignDiameter Design diameter Ddrop Ddrop Vsettling V settling PresBody Body pressure TempBody Body temperature VelBody Body velocity DenBody Body density DescribeCalculations Describe calculations MaxConnectionCount Maximum possible connection count Name The vertical separator name Location The location text Ignore The ignored flag: 0 = not ignored, 1=ignored UpstreamConnection The name of the upstream pipe UpstreamConnectionAt Code for the upstream pipe connection point: 0 = upstream end, 1 = downstream end DownstreamConnection The name of the downstream pipe DownstreamConnectionAt Code for the downstream pipe connection point: 0 = upstream end, 1 = downstream end ConnectedCount Connection count Scenarios Attribute Description Name The scenario name (30 chars) OptionVelConstr Option velocity constraint Done Done HeaderMach Header mach number limit HeaderVapVel Header vapor velocity limit (m/s) HeaderLiqVel Header liquid velocity limit (m/s) HeaderRV2 Header momentum limit (kg/m/s2) HeaderNoise Header noise limit (dB) TailPipeMach Tailpipe mach number limit TailPipeVapVel Tailpipe vapor velocity limit (m/s) TailPipeLiqVel Tailpipe liquid velocity limit (m/s) TailPipeRV2 Tailpipe momentum limit (kg/m/s2) TailPipeNoise Tailpipe noise limit (dB) Pressure System back pressure (bar a) CalculateMe Calculate me SolverOptions Attribute Description AmbientTemperature External temperature (C) AtmosphericPressure Atmospheric pressure (bar a) 208 A File Format Attribute Description CheckChoke Check for choke flow: 0 = No, 1 = Yes Choke Code for choke calculation method: 0 = Simple, 1 = HEM HeatTransfer Enable heat transfer calculations: 0 = No, 1 = Yes ExternalRadiation External radiation Mode Code for calculation mode: 0 = Rating, 1 = Design, 2 = Debottleneck RatedFlow Use rated flow for inlet pipes RatedFlowNodes Use rated flow for downstream nodes attached to tailpipes RatedFlowTailPipe Use rated flow for tailpipes: 0 = No, 1 = Yes WindSpeed Wind velocity (m/s) UseKineticEnergy Include kinetic energy: 0 = No, 1 = Yes IgnoreSepKineticEnergy Ignore kinetic energy in separators: 0 = No, 1 - Yes KineticEnergyBasis Code for kinetic energy basis: 0 = Inlet Pipe Velocity, 1 = Zero velocity CalcIgnoredSources Calculate ignored sources as zero flow: 0 = No, 1 = Yes MabpForInactiveValves Check MABP for inactive sources: 0 = No, 1 = Yes IgnoreSourceSizeChangeWh enSizing Ignore valve flange size change in design calculations: 0 = No, 1 = Yes MaxmumSystemVelocity Maximum system velocity AllScenarios Code to indicate which scenarios are calculated: 0 = Current, 1 = All, 2 = Selected VLE Code for VLE method: 0 = Compressible gas, 1 = Peng Robinson, 2 = Soave Redlich Kwong, 3 = Vapor Pressure Enthalpy Code for enthalpy method: 0 = Ideal gas, 1 = PengRobinson, 2 = Soave Redlich Kwong, 3 = Lee Kesler VleSourceOutletTemp VLE source outlet temperature EnthalpySourceOutletTemp Enthalpy source outlet temperature Horizontal Code for horizontal pressure drop method: 0 = Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3 = Dukler Inclined Code for inclined pressure drop method: 0 = Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3 = Dukler Vertical Code for vertical pressure drop method: 0 = Isothermal gas, 1 = Adiabatic Gas, 2 = Beggs&Brill 3 = Dukler, 4 = Orkisewski Elements Number of elements for two phase calculations FrictionFactor Code for friction factor method: 0 = Round, 1 = Chen UsePipeRoughnessForFitting Use pipe roughness for fitting RoughnessForFitting Roughness for fitting WarnMachForSizing Warn Mach for sizing WarnVelocityForSizing Warn velocity for sizing WarnRhoV2ForSizing Warn RhoV2 for sizing A File Format 209 Attribute Description WarnNoiseForSizing Warn noise for sizing WarnIceFormForSizing Warn Ice form for sizing WarnBPForSizing Warn BPF for sizing WarnChokeForSizing Warn choke flow for sizing WarnSlugForSizing Warn slug flow for sizing WarnTempForSizing Warn temperature for sizing WarnPressureBasis Warn pressure basis WarnPhysPropFailure Warn physical properties failure WarnHeatBalanceFailure Warn heat balance failure WarnChokePresFailure Warn choke pressure failure WarnPresDropFailure Warn pressure drop failure WarnLiqWithVapMethodFail ure Warn liquid with vapour only method failure WarnCorrRangeFailure Warn correlation out of range failure WarnInitWhileSizing Warn initialization while sizing WarnSizeChangeWhileSizing Warn size change while sizing WarnLimitReachedWhileSizi ng Warn limit reached while sizing PresTolProperties Pressure tolerance in properties loop (%) PresTolUnitOp Pressure tolerance for unit operation calculations (%) PresTolLoop Pressure tolerance for loop calculations (%) MassToLoop Mass balance tolerance in outer loop (%) IterationsProperties Number of iterations in inner (properties) loop IterationsLoop Number of iterations for loop calculations DamperProperties Damping factor for inner (properties) loop DamperLoop Damping factor for loop calculations LoopMethod Select loop convergence method: 0=Newton Raphson, 1=Broyden, 2=Force Convergent LoopAnalyser Select analyzer for looped systems: 0 = Convergent, 1 = Simultaneous EchoLoops Are loop calculations echoed: 0 = No, 1 = Yes KeepBad Keep bad UpdateEstimates Update flow estimates from solution: 0 = No, 1 = Yes InitalPressure Initial pressure for property calculations (bar a) LengthMultiplier Pipe length multiplication factor InitPhaseMethodForSizing Initialization phase method for sizing UpstreamMinTemp Upstream minimum temperature DownstreamMinTemp Downstream minimum temperature UpstreamMaxTemp Upstream maximum temperature DownstreamMaxTemp Downstream maximum temperature InletFlowCheck Inlet flow check GaugeInletCheck Gauge inlet check IgnoreInlet Ignore inlet 210 A File Format SourceData Attribute Description ScenarioName The name of the scenario SourceName The name of the source MassFlow Mass flow of the source (kg/h) Ignored The ignored flag: 0 = not ignored, 1=ignored PresAllow Allowable pressure OutletTemperature Outlet temperature (C) InletTemp Inlet temperature InletTempSpec Inlet specified temperature value (C) InletPressure Inlet pressure LockMABP Auto update of MABP: 0 = No, 1 = Yes VLEMethod Code for VLE method: 0 = Model default, 1 = Compressible gas, 2 = Peng Robinson, 3 = Soave Redlich Kwong, 4 = Vapor Pressure FittingLossMethod Code for fitting loss calculation: 0 = Ignored, 1 = Calculated IsothermalPressureDrop Code for enabling isothermal pressure drop calculations: 0 = No, 1 = Yes TwoPhaseCorrection Code for two phase correction option: 0 = No, 1 = Yes SwageMethod Code for size change calculation method: 0 = Compressible, 1 = Incompressible, 2 = Transition CompressibleTransition DP percent of inlet pressure for transition (%) VapourFraction Vapour fraction VapourMolWt Vapour molecular weight IsentropicEfficiency Isentropic efficiency SizingMethod Code for PSV sizing method: 0 = API, 1 = HEM BackPressure Back pressure MultiPhaseCd Multi-phase Cd LiquidCd Liquid Cd Kb Kb RuptureDisk Rupture disk PresCalc Static pressure DenCalc Calculated density VelCalc Velocity TempCalc Temperature ChokeMethod Choke flow check Energy Energy Enthalpy Enthalpy Entropy Entropy Quality Quality Tempincalc Calculated inlet temperature SonicCalc Calculated sonic NonRecoverablePresDrop Piping non-recoverable pressure drop InletVelocity Inlet velocity A File Format 211 Attribute Description InletDensity Inlet density StaticPresDrop Static pressure drop TotalPresDrop Total pressure drop HasProblem Has problem flag HeaderVapourFraction Header vapour fraction HeaderVapourMolWt Header vapour molecular weight HasProblemDp Constraint violation: pressure drop HasProblemVel Constraint violation: velocity HasProblemMach Constraint violation: Mach number HasProblemChoke Constraint violation: choke HasProblemRhoV2 Constraint violation: RhoV2 HasProblemPres Constraint violation: pressure HasProblemTemp Constraint violation: temperature VfCalc Vf calculation StagnationEnthalpy Stagnation enthalpy StagnationEnthalpyCalc Calculated stagnation enthalpy FlowPathCount Flow path count FlowPathName Flow path name FlowPathType Flow path type RatedFlow Rated flow of the source (kg/h) Contingency Code for sizing contingency: 0 = Operating, 1 = Fire LockRatedFlow Auto update of rated flow: 0 = No, 1 = Yes LockReliefPressure Auto update of relieving pressure: 0 = No, 1 = Yes CpCvRatio Cp Cv ratio Compressibility Compressibility InletPresTotalCalc Total inlet pressure PresTotalCalc Total pressure MachNo Mach number RhoV2Calc Rho V2 MolarFlow Molar flow MolWt Fluid molecular weight StaticPresDropForSummary Valve static pressure drop TotalPresDropForSummary Valve total pressure drop Composition Attribute Description ScenarioName The name of the scenario SourceName The name of the source FluidType Fluid type Basis Code for composition input basis: 0 = MolWt, 1 = Mole fraction, 2 = Mass fraction MolWt Molecular weight 212 A File Format PFDLayout Attribute Description ItemName The name of the PFD item XPosition The X coordinate of the item YPosition The Y coordinate of the item LabelXPosition The X coordinate of the item label LabelYPosition The X coordinate of the item label RotationFlipType Code for icon rotation: 0 = None, 1 = Rotate 90°, 2 = Rotate 180°, 3 = Rotate 270°, 4 = Flip X, 5 = Rotate 90° + Flip Y, 6 = Flip Y, 7 = Rotate 90° + Flip X Results Attribute Description ScenarioName The name of the scenario SegmentName The name of the pipe segment MolWt Molecular weight MolarFlow Molar weight MassFlow The mass flow (kg/h) UpstreamTestFlow Test flow of upstream DownstreamTestFlow Test flow of downstream dp_F Pressure drop due to friction (bar) dp_A Pressure drop due to acceleration (bar) dp_E Pressure drop due to elevation change (bar) dp Pressure drop Noise Noise (dB) HtcInternal Internal heat transfer coefficient (W/m 2 /C) HtcConvExternal External heat transfer coefficient (W/m 2 /C) HtcOverall Overall heat transfer coefficient (W/m 2 /C) UpstreamVelocityNonRated Upstream non-rated velocity DownstreamVelocityNonRated Downstream non-rated velocity UpstreamVelocityRated Upstream rated velocity DownstreamVelocityRated Downstream rated velocity UpstreamVelocity Velocity at upstream end of pipe (m/s) DownstreamVelocity Velocity at downstream end of pipe (m/s) UpstreamSonicVelocity Upstream sonic velocity DownstreamSonicVelocity Downstream sonic velocity UpstreamPresTotalNonRated Upstream total non-rated pressure DownstreamPresTotalNonRated Downstream total non-rated pressure UpstreamPresTotalRated Upstream total rated pressure DownstreamPresTotalRated Downstream total rated pressure UpstreamPresTotal Upstream total pressure DownstreamPresTotal Downstream total pressure UpstreamPresStatic Upstream static pressure DownstreamPresStatic Downstream static pressure A File Format 213 Attribute Description UpstreamTemperature Temperature at upstream end of pipe (C) DownstreamTemperature Temperature at downstream end of pipe (C) UpstreamEnthalpy Energy at upstream end of pipe (kJ/kgmole) DownstreamEnthalpy Energy at downstream end of pipe (kJ/kgmole) UpstreamDensity Density at upstream end of pipe (kg/m 3 ) DownstreamDensity Density at downstream end of pipe (kg/m 3 ) UpstreamFlowRegime Flow regime at upstream end of pipe DownstreamFlowRegime Flow regime at downstream end of pipe CanCalc Can calculate Duty Heat transferred (kJ/h) FrictionFactor Friction factor Dp_Fittings Pressure drop due to fittings (bar) RatedFlow The rated flow (kg/h) ReynoldsNonRated Reynolds non-rated ReynoldsRated Reynolds rated Reynolds Reynolds number SourcePres Pressure of attached source node (bar a) Equivlength Equivalent length (m) UpstreamEnergy Energy at upstream end of pipe (kJ/h) DownstreamEnergy Energy at downstream end of pipe (kJ/h) UpstreamEnthalpyEnergy Upstream enthalpy energy DownstreamEnthalpyEnergy Downstream enthalpy energy UpstreamMachNoNonRated Upstream non-rated Mach number DownstreamMachNoNonRated Downstream non-rated Mach number UpstreamMachNoRated Upstream rated Mach number DownstreamMachNoRated Downstream rated Mach number UpstreamMachNo Mach number at upstream end of pipe DownstreamMachNo Mach number at downstream end of pipe UpstreamPresProp Upstream pressure property DownstreamPresProp Downstream pressure property UpstreamRhoV2NonRated Upstream non-rated Rho V2 DownstreamRhoV2NonRated Downstream non-rated Rho V2 UpstreamRhoV2Rated Upstream rated Rho V2 DownstreamRhoV2Rated Downstream rated Rho V2 UpstreamRhoV2 Momentum at upstream end of pipe (kg/m/s 2 ) DownstreamRhoV2 Momentum at downstream end of pipe (kg/m/s 2 ) UpstreamVapourFraction Upstream vapour fraction DownstreamVapourFraction Downstream vapour fraction UpstreamProbChoked Upstream probable choked DownstreamProbChoked Downstream probable choked UpstreamProbMachNo Upstream probable Mach number DownstreamProbMachNo Downstream probable Mach number ProbNoise Probable noise 214 A File Format Attribute Description ProbSourcePres Probable source pressure ProbSource Probable source UpstreamProbRhoV2 Upstream probable Rho V2 DownstreamProbRhoV3 Downstream probable Rho V2 ProbSlugs Probable slug flows UpstreamProbTemp Upstream probable temperature DownstreamProbTemp Downstream probable temperature UpstreamProbVelLiq Upstream probable liquid velocity DownstreamProbVelLiq Downstream probable liquid velocity UpstreamProbVelVap Upstream probable vapour velocity DownstreamProbVelVap Downstream probable vapour velocity PresBody Body pressure DenBody Body density VelBody Body velocity Estimate Estimate CannotTear Cannot tear WallTemperature Temperature of pipe wall (C) MaxStep Maximum step MaxFlow Maximum flow MinFlow Minimum flow HtcRadExt External radiative HTC ExtTemperature External temperature UpstreamVelLiqNonRated Upstream non-rated liquid velocity DownstreamVelLiqNonRated Downstream non-rated liquid velocity UpstreamVelLiqRated Upstream rated liquid velocity DownstreamVelLiqRated Downstream rated liquid velocity UpstreamVelLiq Upstream liquid velocity DownstreamVelLiq Downstream liquid velocity UpstreamVelVapNonRated Upstream non-rated vapour velocity DownstreamVelVapNonRated Downstream non-rated vapour velocity UpstreamVelVapRated Upstream rated vapour velocity DownstreamVelVapRated Downstream rated vapour velocity UpstreamVelVap Upstream vapour velocity DownstreamVelVap Downstream vapour velocity PresDrop Pressure drop over pipe (bar) UpstreamPressure Pressure at upstream end of pipe (bar a) DownstreamPressure Pressure at downstream end of pipe (bar a) TotalPresDrop Total pressure drop EquivlengthForPipeSummary Equivalent length Phase Attribute Description ScenarioName The name of the scenario A File Format 215 Attribute Description SegmentName The name of the pipe segment SegmentEnd End of the pipe segment Phase Phase description Density Density of the phase (kg/m 3 ) Enthalpy Energy of the phase (kJ/kgmole) Entropy Entropy of the phase (kJ/kgmole/K) Fraction Fraction of the phase HeatCap Heat capacity of the phase (kJ/kgmole/K) MolWt Mol Wt of the phase SurfTen Surface tension of the phase (dyne/cm) ThermCond Thermal conductivity of the phase (W/m/K) Viscosity Viscosity of the phase (cP) ZFactor Z Factor of the phase CompResults Attribute Description ScenarioName The name of the scenario SegmentName The name of the pipe segment FluidType Fluid type Basis Basis MolWt The molecular weight of the fluid Fraction The mole fraction of each component Report File Formats The printouts can be customized to a limited extent using a XML file with the extension “.xml”. This file may be edited using any ASCII text editor such as the NOTEPAD application distributed with Microsoft Windows. The default “.xml” file for the printed reports is: ReportFormat.xml By default, the report format file is located in the Aspen Flare System Analyzer program directory. You can change the location and “.xml“ file for the reports on the Reports tab on the Preferences Editor. 216 Fig A.1 The following defines which variable may be printed with each report: Variable Name ambient backpres basis class conductivity connections densitydown densityup description dsn duty elevation energy energyflowdown The following defines which variable may be printed with each report: Variable Description Ambient temperature Back pressure Composition basis Pipe class Thermal conductivity Item connections Downstream density Upstream density Description Downstream node Heat loss Elevation change Energy Downstream energy flow A File Format The following defines which variable may be printed with each report: A File Format 217 Variable Name Variable Description energyflowup Upstream energy flow enthalpy Enthalpy enthalpyflowdown Downstream enthalpy flow enthalpyflowup Upstream enthalpy flow enthalpyup Upstream enthalpy enthalpydown Downstream enthalpy entropy Entropy entropydown Downstream entropy entropyup Upstream entropy equivlength Equivalent length exttemperature External temperature fittinglist Fitting list fittingsa Fitting loss A fittingsb Fitting loss B flange Flange diameter fractiondown Downstream phase fraction fractionup Upstream phase fraction frictionfractor Friction factor group Item group headmach Header mach number headvelvap Header vapor velocity headvelliq Header liquid velocity headrhov2 Header rho V2 headnoise Header noise heatcapdown Downstream heat capacity heatcapup Upstream heat capacity hia Enthalpy A coefficient hib Enthalpy B coefficient hic Enthalpy C coefficient hid Enthalpy D coefficient hie Enthalpy E coefficient hif Enthalpy F coefficient htcradext External radiative HTC htcoverall Overall HTC htcexternal External HTC htcinternal Internal HTC id Item ID ignored Item ignored inletlength Inlet pipe length 218 A File Format Variable Name Variable Description inletelevation Inlet pipe elevation change inletmaterial Inlet pipe material inletroughness Inlet pipe roughness inletnominal Inlet pipe nominal diameter inletschedule Inlet pipe schedule inletinternal Inlet pipe internal diameter inletclass Inlet pipe class Inletfittingsa Inlet pipe fitting loss A Inletfittingsb Inlet pipe fitting loss B insname Insulation description insthick Insulation thickness insconductivity Insulation conductivity internal Internal diameter length Segment length lmultiply Length multiplier location Segment location machdown Downstream mach number machup Upstream mach number massflow Mass flow material Material of construction methoddamping Damping factor methodelements Two phase elements methodfriction Friction factor methodfitlos Fitting loss method methodhordp Horizontal 2 phase pressure drop method methodincdp Inclined pressure drop methodverdp Vertical 2 phase pressure drop method methodvle VLE method molarflow Molar flow molwt Molecular weight molwtdown Downstream molecular weight molwtup Upstream molecular weight multiply Fittings equation multiplier name Item name nbp Normal boiling point node Node nodetype Node type noise Noise nominal Nominal pipe diameter A File Format 219 Variable Name Variable Description number Index number offset Fittings equation offset omega Acentric factor omegasrk SRK acentric factor orificearea Orifice area orifice Orifice pc Critical pressure phase Phase label pressource Static source back pressure presallow Allowable back pressure presdown Downstream static pressure presdrop Pressure drop presdropfriction Static pipe friction loss presdropacceleration Static pipe acceleration loss presdropelevation Static pipe elevation loss presdropfittings Static pipe fitting loss presin Inlet pressure preslimit Back pressure limit presup Upstream static pressure ratedflow Rated mass flow refer Literature reference regime Flow regime resize Resizable flag reynolds Reynolds number rhov2up Upstream rho V2 rhov2down Downstream rho V2 roughness Wall roughness schedule Pipe schedule si Entropy coefficient stddensity Standard density surftendown Downstream surface tension surftenup Upstream surface tension tailmach Tailpipe mach No. tailnoise Tailpipe noise tailpipe Tailpipe flag tailrhov2 Tailpipe rho V2 tailvelliq Tailpipe liquid velocity tailvelvap Tailpipe vapor velocity tc Critical temperature 220 A File Format Variable Name Variable Description tempcalc Inlet temperature calculations tempdown Downstream temperature tempout Outlet temperature tempspec Inlet temperature specification tempup Upstream temperature thermconddown Downstream thermal conductivity thermcondup Upstream thermal conductivity type Item type usn Upstream node valvecount Number of valves valvetype Valve type vapfrac Source vapor fraction vc Critical volume vchar Characteristic volume veldown Downstream velocity velup Upstream velocity visca Viscosity A coefficient viscb Viscosity B coefficient viscdown Downstream viscosity viscup Upstream viscosity wall Wall thickness walltemperature Wall temperature watson Watson characterisation parameter wind Wind velocity zfactordown Downstream compressibility factor zfactorup Upstream compressibility factor B References 221 B References 1 “GPSA Engineering Data Book”. 2 “Chemical Engineering Volume 1”, J. M. Coulson and J. F. Richardson, Pergamon Press, 2nd Edition. 3 “Viscosity of Gases And Mixtures”, I. F. Golubev, National Technical Information Services, TT7050022, 1959. 4 “Chemical Process Computations 1, Chemical Engineering-Data Processing”, Raman, Raghu, Elsevier Applied Science Publishers Ltd, 1985. 5 “Journal Of Physics”, D. J. Berthalot, P.3 ,263. 6 “Technical Data Book-Petroleum Refining”, American Petroleum Institute, 1977. 7 “A Computer Program for the Prediction of Viscosity and Thermal Conductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanley, NBS Technical Note, 1039, 1983. 8 R.W. Hankinson and G.H. Thompson, AIChE Journal, 25, 653, 1979. 9 “A Study of Two-Phase Flow in Inclined Pipes”, H.D. Beggs and J.P. Brill, J. Petrol. Technol., P. 607, May, 1973. 10 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3, 1982 by Campbell Petroleum Series, 2nd edition, 1990. 11 J. Orkiszewski, Journal of Petroleum Technology, B29-B38, June, 1967. 12 “Gas Conditioning and Processing”, R. N. Maddox and L. L. Lilly, Volume 3, 1982 by Campbell Petroleum Series, 2nd edition, 1990. 13 API Technical Data Book Volume 1, American Petroleum Institute, 1983. 14 R.W. Hankinson and G.H. Thompson, A.I.Ch.E. Journal, 25, No. 4, P.653 1979. 15 “The Properties of Gases &Liquids”, R.C. Reid, J.M. Prausnitz and B.E. Poling, McGraw-Hill, Inc., 1987. 16 “A Computer Program for the Prediction of Viscosity and Thermal Conductivity in Hydrocarbon Mixtures”, J.F. Ely and H.J.M. Hanly, NBS Technical Note 1039. 17 “Molecular Thermodynamics of Fluid Phase Equilibria”,J.M. Pausnitz, R.N. Lichtenthaler and E.G. Azevedo, 2nd Edition, McGraw-Hill, Inc. 1986. 18 C.H. Twu, IEC. Proc Des & Dev, 24, P. 1287, 1985. 19 “Viscosity of Crude-Oil Emulsions”, W. Woelfin, Spring Meeting, Pacific Coast District, Division of Production, Los Angeles, Calif., Mar. 10, 1942. 20 W.R. Gambill, Chem Eng., March 9, 1959. 222 B References 21 “An Explicit Equation for Friction Factor in Pipe”, N.H. Chen, Ind. Eng. Chem. Fund., 18, 296, 1979. 22 “Sizing, Selection, and Installation of Pressure - Relieving Devices in Refineries”, API Recommended Practice 520, Part I, 6th Edition, American Petroleum Institute, March, 1993. 23 “Guide for Pressure-Relieving and Depressuring Systems”, API Recommended Practice 521, 3rd Edition, American Petroleum Institute, November, 1990. 24 “Easily Size Relief Devices and Piping for Two-Phase Flow”, J.C. Leung, Chem. Eng. Prog., P. 28, December, 1996. 25 “Internal Flow Systems”, D.M. Miller, 2nd Edition, BHR Group Limited, 1990. 26 “Flow of Fluids Through Valves, Fittings and Pipe”, Crane Technical Paper 410M. 1988. 27 “PIPE 3, Single and Two-Phase Pressure Drop Calculations in Pipeline Systems”, HTFS Design Report 38, 1996. 28 “Les Pertes de Charges dans les Écoulements au Travers de”, A. Gardel, Bulletin Technique de la Suisse Romande, 83, 1957. C Glossary of Terms 223 C Glossary of Terms Adiabatic Flow Adiabatic flow is the constant enthalpy flow of a fluid in a pipe. Choked Flow The velocity of a fluid in a pipe of constant cross-sectional area cannot exceed the sonic velocity of the fluid. If the flow of fluid in a pipe is great enough that the sonic velocity is reached, then a pressure discontinuity is seen at the exit end of the pipe. Critical Pressure The critical pressure is the pressure at which the vapor density and liquid density of a substance may be the same. Critical Temperature The critical temperature is the temperature at which the vapor density and liquid density of a substance may be the same. Dongle See Security Device. Equivalent Length The equivalent length of a pipe is the straight length of pipe which would create the same pressure drop as the actual pipe length plus losses due to bends and fittings. 224 C Glossary of Terms Isothermal Flow Isothermal flow is the constant temperature flow of a fluid in a pipe. In general when the pressure of a gas reduces, there is a small change in temperature. This assumption leads to a small error in the calculated pressure profile. In practice, for pipes of length at least 1000 diameters, this difference does not exceed 5% and in fact never exceeds 20%. MABP The Maximum Allowable Back Pressure on a relief device is the maximum pressure that can exist at the outlet of the device without affecting the capacity of the device. In general the MABP for a conventional pressure relief valve should not exceed 10% of the set pressure at 10% overpressure. In general the MABP for a balanced pressure relief valve should not exceed 40% of the set pressure at 10% overpressure. Mach Number Mach number is the ratio of the fluid velocity to the sonic velocity in the fluid. Node Nodes define the connection points between pipes, and pipes with sources. Each node must have a unique name. Reduced Pressure Reduced pressure is the ratio of the absolute pressure to the critical pressure of the fluid. Reduced Temperature Reduced temperature is the ratio of the absolute temperature to the critical temperature of the fluid. Scenario A scenario represents a set of flow and compositional data for all sources in the system. It may also represent a particular set of limiting operating conditions. C Glossary of Terms 225 Schedule The schedule of a pipe defines a standard thickness for a given nominal pipe size. In general, flare and vent systems are constructed from schedule 40 or 80 pipe. Security Device The hardware device that is connected to the parallel port of the computer. Source A source refers to a fluid entering the piping network regardless of the type of pipe fitting from which it enters. the fluid is defined in terms of its composition, mass flowrate, pressure and temperature. Static Pressure The pressure acting equally in all directions at a point in the fluid. Physical properties are calculated at the static pressure condition. Tailpipe The section of pipe between the discharge flange of the source valve and the main collection header is generally referred to as a tailpipe. Total Pressure The sum of the static and velocity pressures. Velocity Pressure Given by 2 ρU 2 , also called the kinematic pressure. 226 Index Index A Automation 115 B binary interaction parameters 11 C calculations sizing 104 speed 103 status 101 stop 101 type 101 Component Editor 6 Component Manager 3 components binary interaction parameters 11 changing 11 combining 11 estimating unknown properties 10 list 4 name string 5 selecting 4 selection filter 5 type 4 updating with user data 10 Connector 43 Control Valve 71 D data adding/deleting 109 filters 108 printing 109 protection 110 tables 109 Database Editor Index 227 component 112 fittings 112 pipe schedule 110 database features adding/deleting data 109 grid controls 108 F Flare Tip 95 Flow Bleed 47 H Horizontal Separator 50 M modeling flare networks primary objectives 102 recommended sequence 102 N Node Manager 41 nodes Connector 43 Control Valve 71 Flare Tip 95 Flow Bleed 47 Horizontal Separator 50 Orifice Plate 56 Relief Valve 81 Tee 60 Vertical Separator 65 Nodes 41 noise 186 O Orifice Plate 56 P password setting 110 physical properties 178 Pipe Class Editor 39 Pipe Manager 25 pipes multiple editing 38 Pipe Class 39 pressure drop methods 157 228 Index R Relief Valve 81 S Scenario Editor 17 Scenario Manager 16 scenario selector 16 scenarios 15 adding single source 23 adding/editing 17 tools 23 sizing recommended procedure 104 source tools 94 adding single source scenarios 95 updating downstream temperatures 95 sources Control Valve 71 Relief Valve 81 tools 94 Status bar 101 T Tee 60 V vapour-liquid equilibrium 175 Vertical Separator 65 VLE method 103