LNG Density Calculations (2016 by RUB)

RUHR-UNIVERSITÄT BOCHUMLNG Training Course – Density Calculations 4th International Workshop “Metrology for LNG” NPL, Teddington, UK | 2016/06/15 M. Richter, C. Tietz, R. Kleinrahm, R. Lentner, R. Span 567: the gross calorific value of the LNG loaded or unloaded in MMBTU/kg. LNG Custody Transfer General Formula for Calculating the LNG Energy Transferred (According to GIIGNL . 𝑉567: the volume of LNG loaded or unloaded in m3. | 4th International Workshop “Metrology for LNG” | June 2016 2 . Richter et al. 𝜌567: the density of LNG loaded or unloaded in kg/m3. 𝒙 ' 𝑯𝐒. 𝐻:. or from the LNG carrier to the unloading facilities.LNG Custody Transfer Handbook) 𝑬 = 𝑽𝐋𝐍𝐆 ' 𝝆𝐋𝐍𝐆 𝑻.𝐋𝐍𝐆 𝒙 𝐤𝐖𝐡 𝐸: the total net energy transferred from the loading facilities to the LNG carrier. 𝒑.   ­  graphic method of RC MILLER.  Its  uncertainty  is  ±0. a subset of  A variety of calculation methods exists [6].   GIIGNL 2015  spreadsheet or a computer programme is often used.1%.  also  using  the  revised  KLOSEK­ outliers (the whole analysis must be eliminated). One of the numerical tests recommended in    LNG  produced. 70% of nominal rate.  These  techniques are  explained in ISO  5725­2  method  also  encompass  the  composition  of  most  standard.  There  are  different  approaches  to  determine  the  as  described  in  N.      The  aim  of  the  data  treatment  is  to  obtain.  from  a  ­  WATSON method.B.00  presence of outliers.  when  either    this  standard  for  dealing  with    outliers  is  the  Grubbs’  the  nitrogen  or  butane  content  does  not  exceed  5%.  statistical point of view.g.    GIIGNL ­  ­  state equations in their integral form.   ­  ship’s LNG cargo discharge pumping rate is lower    than a preset value.  Appendix  8  shows  the   procedure  to  apply  this  For  these  density  calculations  an  electronic    test as well as a numerical example. such as:  acceptable  LNG  compositions  is  ready  for  data  treatment. The limits of the  tests.            This data  treatment step  results  in  a  final  LNG  molar  Comparison between the revised KLOSEK- Richter th et al.  the  whole  LNG  3 . It is easy to apply  be  inconsistent  and  may  change  the  final  result:  and  only  requires  the  LNG  temperature  and  graphical consistency technique and numerical outlier  composition to be taken into account.    ­    evaluating  the  elimination  or  not  of  the  detected    ­  ISO  6578.  ­  performing a statistical test for each analysis and      each  LNG  component  in    order  to  determine  the  ­  revised  KLOSEK­McKINLEY  method  (k1  and  k2  FOURTH EDITION version 4.  method of extended corresponding states.  tables in Kelvin: K).  k2  tables  in  degrees  Celsius: °C). Data treatment   ­  hard sphere model method.  LNG CUSTODY TRANSFER LNG.2. e.    test.  Validation of these density models by experimentation  ­  normalizing the final LNG composition.  the  preferred    method  is  the  revised  KLOSEK­McKINLEY  method.  – cf.  McKINLEY  method  (k1. | 4 representative  International for  Workshop “Metrology for LNG” McKINLEY| June 2016using tables in Kelvin (NBS) and method composition. CTH METHODS _________________________________  After performing this data processing step.  is ongoing  (Ref [18]). In this  handbook.2.  This step consists of:  HANDBOOK ­  HIZA method. a robust and consistent result  that  best  reflects  the  quality  of  the  whole  transferred  ­  ELF­AQUITAINE method.    _________________________________  8.  Technical  note  1030  presence of individual values in a set of data that may  December 1980 [9] or in ISO 6578.2.  ­  calculating  the  average  composition  from  the    analyses not being rejected.S.  9. DENSITY CALCULATION LNG Density Calculation Methods ­  other criteria particular to the analyses. s. McCarty ft-/-ZV7 NBS TECHNICAL NOTE 1030 u. CONCLUSIONS On the basis of the performance of the four models given here and subject to the composition and temperature restrictions already noted. McCarty (1980): • extended corresponding states • hard sphere method therefore requires • cell method twelve significant figures to insure the accuracy of the calculated density. et al. Haynes. Hiza and Haynes [15]. LNG Density Calculation '5'=-/35'3 Methods – cf. it is estimated that given the pressure. Hiza. any one of the four models may be used to predict the density to within 0. DEPARTMENT OF COMMERCE 'National Bureau of Standalds Models investigated by R. et al. Richter et al. D. et al. temperature and composition of LNG. [11].1% of the true value. • revised Klosek and McKinley method The other two models require only eight significant figures to be carried along in the calculations. [14]. [13]. | 4th International Workshop “Metrology for LNG” | June 2016 4 . Haynes [g]. As has already been mentioned (see section I) the above accuracy statement is dependent entirely upon the accuracy of the experimental data in Haynes. 7. Property Package is not limited to a single simulation software Fundamental contributions to the optimisation of systems can be alone. The GERG-2008 Applied Property EnergyPackage uncertainty of the composition. 3. For these simulations an accurate representation for the different phases of a mixture or a pure compound. An Florian Dauber . a r t i c l e i n f o tifically aand b s t rindustrially a c t most often used process modelling Article history: Accurate simulations are important for efficient design and operation of a process. NIST) by Haynes Contents lists available at SciVerse ScienceDirect uncertainty of Dq0 /q0 6 0. New. Liquefaction ! 2011 Elsevier Ltd.elsevier. The influence of property models on the simulation of the most important pro- CAPE-OPEN cesses of the LNG value chain is investigated. The GERG-2008 by Kunz on process simulation. Applied Energy 97 (2012) 822–827 Bureau of Standards in the USA (today: dards and Technology. Transport 1. This standard defines rules and interfaces that allow Evaporation. | 4 Workshop “Metrology for LNG” | June 2016 arbitrary composition consisting of up to 21 specific compounds. Germany es calculated with the equation of Peng– ronments enables a consistent and stable calculation in the scien- than 10% from results of the GERG-2008.models Fur. Universitätsstr. High expectations on the economic effi. The Property Package is a consistent collection of methods expected from detailed and sufficiently accurate simulations of and compounds for calculating any of a set of physical properties the processes. the GERG-2008 Property Package has been developed.perimental data represent different com. model used. et al. The LNG densities were equation of state inevitable. with Kwong and different Soave [5] are takenproperty into account. The experimental Since the GERG-2008 equation of state describes the whole fluid journal homepage: www. Results show the expected advantages in accuracy for sim- Liquefied natural gas ulations using the new property model. In order to model LNG processes with the highest accuracy available.3%. region of natural gases and similar mixtures with an accuracy that Shell-Laboratory in Amsterdam. which meets the GERG-2008 Vapourisation CAPE-OPEN standard. 0. To ensure Keywords: stable and consistent simulations. the developed GERG-2008 increasing demands on design and operation of these systems. Therefore. The Received in revised form 13 November 2011 GERG-2008 by Kunz and Wagner [1] is the new reference equation of state for natural gases consisting Accepted 14 November 2011 of up to 21 specific compounds.1%. 150. However. the product quality and environmental safety result in ous commercial simulation tools. 44780 Bochum. state by Lee and Kesler [6] in connection with the mixture model . While the standard is supported by vari- ciency. All rights reserved. which makes an implementation of the GERG-2008 LNG Density Calculation Methods – Wide Range re calculated. highly accurate equations of state represent an In order to examine the influence of different property models unused potential for process modelling. the total ounts to approx. is beyond those of industrially used equations of state. the modified Benedict–Webb–Rubin type equation of 5 It covers the gas and liquid phase as well as the super-critical re. smaller Modelling liquefied-natural-gas processes using highly accurate property models nd Zeldenrust [11]. The uncertainty is ⇑ uncertainties for process simulation can be expected as well. Nether. from Richter 2008. a precise Received 27 June 2011 representation of thermophysical properties using an adequate property model is necessary. software available for the new equation is implemented into various common simulation tools. It describes the gas and liquid phase as well as the super-critical region Available online 7 December 2011 and the vapour–liquid equilibrium. Introduction implemented in a software component adhering to the CAPE-OPEN standard [3]. thermore. property models have a crucial impact on the accuracy of process ourse considered when deviations to the simulations. the Property Package allows consistent and stable calculations of Results of process simulations are influenced by the property thermodynamic properties. implementation of the GERG-2008 equation into simulation envi- Ruhr-Universität Bochum.com/locate/apenergy capacities of a LNG mixture were mea. Using of thermophysical properties is essential. cubic equations by Peng and Robinson [4] saturated liquid densities of LNG th International measured and Wagnerby[1]Hiza is an and Haynes equation [9]describes of state that and Haynes mixtures of[10]and and calculated by Redlich. Roland Span with Dcp/cp 6 1%. ponents to interoperate. transport and liquefaction are important processes Computer-Aided Process Engineering (CAPE) applications or com- in the LNG process chain. Thermodynamics. of multi-fluid approx. propane. storage. Themixtures normalofrange along with functions developed for the binary the components of to take into account the residual Gaz naturel — Calcul des propriétés thermodynamiques — 4.1 is the only natural thermodynamic properties — of gases. gasesfractions storage facilities. GERG-2004 form n-pentane. The is given by precooling. heat exchangers. homogeneous gas. and supercritical regions and for r vapor−liquid equilibrium (VLE) states. and processes to separate gas components.approximation. This involves the separation of a number of components that are either undesirable (e. compressors. Gaz naturel — Calcul des propriétés thermodynamiques — Article INTERNATIONAL ISO First edition Partie 2: Propriétés des phases uniques (gaz. These data can be Lehrstuhl r Thermodynamik. 3032−3091 thus making it transportable by specialized tanker ships. The term gas technical application carbon dioxide. T .GERG-2008 expanded value onversion their ofown equation applications the GERG-2004 of state equation of state.as butane. in this water. the Single-phase properties (gas. Thisequation involvesofthestate for the of separation thermodynamic a number gases and ofother properties mixtures developed by Kunz et al. INTRODUCTION The dimensionless The accurate knowledge of the thermodynamic properties of natural gas (LNG). | 4th International Workshop αoi is “Metrology for the The processed natural gas is transported in gaseous form N through pipelines at pressures up to 12 MPa. the undesirable is anmore or have (e. the where and heavier hydrocarbons and also helium). equations and salt the mole caverns. and processes to separate gas components. and supercritical regions and for αo(ρ . Compressor LNG”residual | June 2016 part of the reduced Helmhol GERG-2004 equation of state is based on a multi-fluid 6 approximation. natural gas in its raw form in general needs to be r homogeneous gas.stations gas incomponents. is presented carbon dioxide. and subcooling cycles. Natural gasfluid) and dense Article — Calculation of ranges for extended through n-hexane. calculatedGermany in a very convenient way from equations of state. Comparisons with In situations where major gas-transmission and Peng−Robinson Received: equation June(P-R). and(gas. Over the entire composition range. 17. thus making it transportablepubs. applications. liquid. For the applications described above. up to 12 MPa. equation of state that is appropriate for nearly all of the technical composition x̅ according to water. x ̅ ) general structure(8) components is of indispensable importance for the basic engineering and performance of technical processes. propane. and liquefaction of natural gas are examples for technical applications where the facilities requires property calculations over wide ranges of 2015-01-15 thermodynamic † O. fluide dense)  explicit in the reduced HelmholtzInfree 1.g. heat exchangers. These data can be calculated in a very convenient way from equations of state. liquid. properties K and behavior.the other pressures The quantities liquid. n-octane. are also presented.. Chem. AGA8-DC92 and Peng−Robinson equation (P-R). the design of processing.g. pipelines or by shipping. 2012 ISO 20765-2:2015(E) Gaz naturel — Calcul des propriétés thermodynamiques — Partie 2: Propriétés des phases uniques (gaz. transportation. liquide. periodically hydrogen along the pipeline sulfide. for example. transportation through are also presented. and vapor− liquid equilibrium states for mixtures of these components. ensure the the state that Over and argon.n-decane.. Eng.1 is the only i=1 liquefaction facilities. Partie 2: Propriétés des phases uniques (gaz. monoxide. τ .dx. x ̅ ) + α (δ . Data 2012.. liquefaction.areand hydrogenThissulfide) other either equation mixtures.are Examples propane. in methodsincludes of GERG-2008 large cost component The used to temperatures calculate flow rates uncertainties. storage. a function of density. Ruhr-Universitä t Bochum. the residual part of the re a multi-fluid © 2012 American Chemical Society The accurate knowledge of the thermodynamic properties of 3032 natural gas (LNG). liquide. ethane. natural 20765-2/3) of mixing. liquid.doi. Wagner*properties of a variety of mixtures of natural mixture compositions and operating conditions in the N ∑Natural gas components are required. and storage gas are examples for technical applications where the facilities requires property calculations over wide ranges of thermodynamic properties of a variety of mixtures of natural N mixture compositions and operating conditions in the o part à α (δ . n-butane.1. up GERG-2004 to 35 MPa where experimental data of the thermal and caloric properties are represented to within their accuracy. and storage First edition Other Mixtures: An Expansion of GERG-2004 processing. τ . 2012 for natural Published: October 31. that is appropriate for nearly all of the technical described above and that satisfies the demands on equation. processing.—TCalculation ) + ln xofi] To meetfüpipeline-quality specifications or for commercial use vapor−liquid equilibrium (VLE) states.org/10. compressors. ethane. temperature T. transportation. x ̅ ) = xi[αooigas (ρ . Similar to other recent developments. natural gas in its raw form in general needs to be The GERG-2004 wide-range equation of state for natural processed ahead of the feed into gas-pipeline systems or ABSTRACT: liquefaction A new facilities. GERG-2008 covers the gas phase. butane. Similar to other recent developments.g. 2012 n-butane. The processed nitrogen.gas allow remains pressurized. and molar processed ahead of the feed into gas-pipeline systems or The GERG-2004 wide-range equation of state for natural gases and other mixtures developed by Kunz et al. as a fuel. 57. and argon. and subcooling cycles. T . liquid phase. isobutane. Richter et al. Compressor hydrogen. The normal range of ρr = ρr (x ̅ ) Part 2: LNG Density Calculation Methods – Wide Range validity of GERG-2008 includes temperatures from (90 to 450) K and pressures up to 35 MPa where the most accurate experimental data of the thermal and caloric properties are represented to within their accuracy. rangeand nitrogen. the entire fluid region. GERG-2008 will be adopted as an ISO Standard (ISO 20765-2/3) for natural gases. oxygen. use of GERG-2008 and other for all ofsuch of AGA8-DC92 mixtures of the theasvarious of mixture depleted of constituents. To GERG- from in(90 match to 450) mixture large iSingle-phase (see eq 12). D-44780 Bochum. thermodynamic properties — monoxide. helium. similar that components andwork. x ̅ ) = ∑ xiαoi(δ . liquid. The and also helium). storage and liquefaction of natural gas.gas is transported ethane. applications described above and that satisfies the demands on the accuracy in the calculation of thermodynamic properties over r the entire fluid region. liquefaction. represents ther properties of the ideal-gas To meet pipeline-quality specifications or for commercial use as a fuel. Numerical Description Small scale differences validity metering can introduce stateofofGERG-2008. carbon dioxide. τ . mixture at a given mixture density ρ. gas isgases. other theunderground aquifers. (60 tonatural 700) Kgas andis up injected to 70 at MPa. and dense fluid) for extended ranges pressures The givenup tonumerical information the sophisticated derivatives) 2008 equation of state for natural 30enables MPa into reservoirs. The mixture model uses accurate equations of . GERG-2008 for equilibrium liquid monitoring and dimensionless form ofPart covers the gas managing states In addition. The extended validitygases calculation of thermal mixtures consisting and (including of caloric all18 equation properties ofcomponents: theof most for state enables accuratethe natural methane. storage and liquefaction of natural gas. liquide. the design of fractionation units. transportation through STANDARD of application 20765-2 Tr = Tr(x ̅ ) pipelines or by shipping. The given numerical information (including all of the sophisticated derivatives) enables the use of GERG-2008 for all of the various technical applications. the economics of state. and liquefaction of natural fractionation units.org/jced tanker ships. x ̅ ) where the α part residual gas components are required. Modern and highly efficient liquefaction processes pour une gamme étendue d’applications © ISO 2015 r use mixtures of natural gas components as refrigerants in Helmholtz free natural gases and other mixtures consisting of natural gas o r energy of α(δ . fluide dense)  pour une gamme étendue d’applications 2015-01-15 1. entireincomposition the form of fundamental equations for each mixture thermodynamic of application properties — natural range. and dense fluid) for extended ranges reaches from (60 to 700) K and up to 70 MPa. helium. αoo andandheavier hydrocarbons composition. n-pentane. n-nonane. INTRODUCTION energy approximation. supercritical region. temperature. ethane. hydrogen sulfide. where N is the number of components in the mixture. carbon The mixture model uses accurate equations of stations placedwater. For the applications described above. the natural for mixtures metering phase. equation is based on 21 natural gas components: methane. and vapor− the pipes. The the mixture α is given by: precooling. of these region. GERG-2008 will be Reference number natural gas components is based pipelines adoptedareasnotan viable (primarily ISO Standard on a multi-fluid accounts across (ISO cooled and condensed into liquid form. equation of state is based on a multi-fluid isopentane. Accepted: August 2. Modern and highly efficient liquefaction processes use mixtures of natural gas components as refrigerants in by specialized form STANDARD of the Helmholtz 20765-2 free energy o α natural gases and other mixtures consisting of natural gas ideal-gas mixture components is of indispensable importance for the basic The GERG-2008 Wide-Range Equation of State for Natural Gases and engineering and performance of technical processes. isobutane. for example. liquid the2:Helmholtz free energy in the id supercritical component phase.acs. Comparisons with other equations of state. i = 1Part 2: the accuracy in the calculation of thermodynamic properties over GERG-2008 than when left isin explicit in thegasHelmholtz the natural free energy (e. Kunz and W. and hydrogen sulfide) or have more value on their own than when left in the natural gas (e.g. τ . fluide dense)  pour une gamme étendue d’applications supply reachesandfrom demand. Examples are processing. carbonnatural dioxide. water. τ ) + Δα (δ .pipelines at pressures n-heptane. x ̅ ) = α (ρ .. known as liquefied approximation for the entropy oceans).1021/je300655b | J. gases. The extended validity range INTERNATIONAL ISO Single-phase properties (gas. in gaseous propane. Robinson (1976) • Modified BWR EOS of 𝜔 P 𝜔 ref 𝑍= 1+ 𝑍 + 𝑍 Lee and Kesler (1975) 𝜔 ref 𝜔 ref and Plöcker et al. | 4th International Workshop “Metrology for LNG” | June 2016 7 . β (which are not fluid specific) Richter et al. γ. D are calculated by means of the critical parameters (as a function of the composition and pure substance parameters) and a binary specific mixture parameter the equation contains 25 general constants. e. const. c4.D '>' >E@ and Kwong (1949) • Cubic EOS of Peng and <'= B 𝑝 = >?@ − >' >E@ E@' >?@ a.. b: fluid spec.g. (1978) ref /P 𝑝r 𝑣r 𝑍 = 𝑅𝑇r 𝐵 𝐶 𝐷 𝑐[ 𝛾 𝛾 = 1 + + W + Y + \ W 𝛽 + W exp − W 𝑣r 𝑣r 𝑣r 𝑇r 𝑣r 𝑣r 𝑣r B. C. LNG Density Calculation Methods – Wide Range • Cubic EOS of Redling <'= B 𝑝 = >?@ − =C. was estimated to be up Richter et al. 115. Within the present project. in the homogeneous liquid Accepted 29 September 2015 region. The apparatus is Available online 8 October 2015 designed for measurements over a temperature range from (90 to 300) K at pressures up to 12 MPa. All rights reserved.07 to 0. | 4th International Workshop “Metrology for LNG” | June 2016 ‘‘demand for natural gas grows by more than half. Chem. It covers the density range from (10 to 1000) Received in revised form 22 September 2015 kg ! m"3. D-44780 Bochum. LNG Density Calculation Methods – Wide Range • COSTALD 1 − 𝐶 ln(𝐵 + 𝑝) 𝑣 = 𝑣′ ' (corresponding states 𝐵 + 𝑝s liquid density) by 𝑣n = 𝑣∗ ' 𝑣r ' 1 − 𝜔 ' 𝑣r P p Hankinson and Thomson (1979) B and C are calculated by means of the critical parameters and the acentric factor (as a function of the composition and pure substance parameter à without specific mixture parameter) J.. 8 . given in Reference [3] for calculated densities.elsevier. 120. Germany a r t i c l e i n f o a b s t r a c t 0. is probably underestimated.3 Development of a special single-sinker densimeter for cryogenic liquid mixtures and first results for a liquefied natural gas (LNG) 0. the Natural gas is an important energy source today and for the uncertainty of these data. First results for a synthetic five-component LNG mixture were Magnetic suspension coupling obtained at the temperatures T = (105. Chem. Roland Span Lehrstuhl für Thermodynamik. The density can be obtained directly without the need for calibration fluids. thus enabling density measurements in the supercritical region. e. Rafael Lentner. which represents the experimental values within 0. Thermodynamics 93 (2016) 205–221 LNG (type: Norway).1 MPa. The densimeter is based on the Archimedes (buoyancy) principle and is a single-sinker system 0 Keywords: Cryogenic liquid mixtures incorporating a magnetic suspension coupling.3%.5) MPa 0. exp. ! 2015 Elsevier Ltd. along the saturated liquid line as well as in the homogeneous gas region. Klosek-McKinley COSTALD correlation 1. According to the International Energy Agency [1] the [4] as well as by Hiza and Haynes [5–7]. it can be stated that an uncertainty of 0. liquefied natural gas (LNG). Thermodynamics journal homepage: www. The relative combined expanded uncertainty (k = 2) for density measurements in 105 110 115 120 125 130 135 Density measurement Single-sinker densimeter Liquefied natural gas (LNG) the homogeneous liquid region (including the contribution resulting from the uncertainty of the sample gas analysis) was estimated to be 0. Thus.g. mostly measured by Miller and Hiza future.com/locate/jct 0. The results T/K Synthetic gas mixtures were compared to the GERG-2008 reference equation of state for natural gases.1%.2 Markus Richter ⇑.1 Article history: A special densimeter has been developed for accurate density measurements of liquid mixtures at Received 9 August 2015 cryogenic temperatures. p = (0. the fastest rate among the fossil fuels.06%. Ruhr-Universität Bochum.044%. and increasingly flexible global trade in liquefied natural gas (LNG) offers some protection against the risk to about 0. data (this work) Rev. Reiner Kleinrahm. and 135) K with pressures up to 8. 125.4 100 (ρ'exp−ρ'GERG)/ρ'GERG Contents lists available at ScienceDirect J. Introduction and pressure range and was fitted to a comparatively small number of experimental data. wxyy = 𝑝v. LNG Density Calculation Methods – ERKM (ERKM = Enhanced Revised Klosek and McKinley Method) The original RKM-method: 𝑥6W 𝑣rst = € 𝑥‚ ⋅ 𝑣‚ − 𝑘~ + 𝑘W − 𝑘~ ⋅ ⋅ 𝑥†‡[ Fitted constants ‚ 0.05 MPa ⋅ 𝑇 − 95 K Richter et al. | 4th International Workshop “Metrology for LNG” | June 2016 9 .wxyy ⋅ 4.06 ⋅ 10 ⋅ 𝑣rst 𝑇}w − 𝑇 A pseudo-critical temperature to avoid deviations at higher temperatures: 𝑇}w = € 𝑥‚ ⋅ 𝑇w.‚ ‚ A correction term for the saturation pressure: 𝑝v.0425 ~.•• 𝑀rst ?[ 𝑇}w 𝜌567 = ⋅ 1 + 𝑝 − 𝑝v.11 MPa ⋅ 𝑇 − 90 K − 𝑥†W‡Œ ⋅ 0.†‡[ + 𝑥6W ⋅ 0. 1 % for 100 K ≤ 𝑇 < 115 K and 𝑝v ≤ 𝑝 < 5 MPa Uncertainties: 0. LNG Density Calculation Methods – Performance of ERKM Estimated 0.15 % for 115 K ≤ 𝑇 ≤ 135 K and 5 MPa ≤ 𝑝 ≤ 10 MPa Richter et al. | 4th International Workshop “Metrology for LNG” | June 2016 10 . The coefficients for the mixture departure functions are stored in a single text file. in the usual fashion of a ows application. a table displaying the results appears. Underlying these subroutines are sets of core routines for each of the models example is varied from pure component 1 to pure component 2 with increments of 0. and a disclaimer. U. CV. which allow selected data or plots to be exchanged with applications. CP0 and Q. REFPROP 17 Figure 1: ALLEOS routine The input parameters must have the types according to Table 2: verview of the Menus ile menu provides commands to save and print generated tables and plots. se of the Database he REFPROP program by double-clicking on its icon. B. respectively. In order to use the ALLEOS routine. The standard Print. dit menu provides copy and paste commands. The property models are written in FORTRAN and sed by the GUI through a dynamic link library (DLL). The interface provides a convenient means to Enter subroutines calculate need to be implementing and display pushed a variety thermodynamic of at the time instead of just Enter or clicking ok. a range of 15 cells needs to be selected. A click on the fx button atabase Structure after typing “ALLEOS(“opens the optional context menu (see Figure 1). and Exit ands are also present. the out iterative composition of the binarysaturation varied from the condition indicated in the "Initial" column to that in the "Final" column using the number of system shown in the and flash calculations are independent of the property models. While the calculations are in progress. such as spreadsheets. H. S. click the Cancelcoefficients to the Clicking the OK button initiates the calculations. onal files contain information specifying predefined or user-defined mixtures. To stop the numerical calculations. Richter et al. ng the "Continue" button starts the program. CP.1 in mass fraction. D. The property subroutines can also be used by applications. a small window button. as described in Appendix B. by the use of pull-down menus displayed across the top of the application window. indicating The status. After finishing the inputs LNG Density Calculation Methods – Software Ctrl+Shift+ ROP consists of a graphical user interface (GUI) and FORTRAN roperty models. independently of the GUI. The program is controlled. WS. | 4th International Workshop “MetrologyREFPROP for LNG” 3 | June 2016 11 . that With 11carry points. Clicking the "Information" button calls up further details and credits through the help system. Individual items or entire à In industry often individual in-house solutions are used! ns with multiple windows can be saved or recalled. The 15 selected cells will then be filled with T. This structure simplifies dition of new fluids and additional models to future versions of the database and makes such additions t totally transparent to the user. mentedappearsin thetheprogram. G. credits. complete. A. A banner screen displays the title. ansport properties of pure fluids and mixtures. C. Print Setup. The constant property (temperature or pressure) is entered at the upper left. P. When the calculations are property models for each fluid are stored in ate text files. The composition will be linearly igh-level subroutines points indicated at the upper right. LNG Density Calculation – e. the RKM-method was also implemented Richter et al.g. | 4th International Workshop “Metrology for LNG” | June 2016 12 . TREND Package Demonstration of current TREND 2 BETA Version (Software is only for demonstration and personal use! Do not distribute!) * not applicable for the RKM-method. à Beside the ERKM-. | 4th International Workshop “Metrology for LNG” | June 2016 13 .Richter et al.