1HYDERABAD GAS TURBINE STARTUP GAS TURBINE ENGINEERING - FES 2 HYDERABAD OBJECTIVES To smoothly start,Accelerate and bring the Gas Turbine to full Speed No Load Condition GAS TURBINE ENGINEERING - FES 3 HYDERABAD PRE START UP CHECKS All MCC modules are switched µON' and are kept on µAuto¶ Lube Oil Level is OK & Oil temp. normal Select ³Cooldown On´ and ensure that the AC Lube Oil Pumps starts & Ratcheting is OK. Start EOP and ensure that the pressure developed is OK Cooling Water level is OK Visual Inspection of Machine is OK GAS TURBINE ENGINEERING - FES Normal Start HYDERABAD 4 Select ³UNIT CONTROL´ Display Operator selects ´CRANK / FIRE /AUTOµ then µExecute¶ Protections System checks Ready to Start Permisives: 01. Generator Lockout Relay is Reset 02. Turbine is at Zero Speed 03. Overspeed Bolt is Reset 04. Flame is not Detected in all Scanners 05. Compressor Bleed valves are Open 06. ¶OFF · is not Selected 07. IGV is Closed 08. Master protective ¶4· Logic is Reset 09. <R> <S> and <T> Master Protectives agree 10. Emergency Lube Oil Pump Voltage is Normal 11. Diesel Test is not in Progress 12. <R> <S> and <T> Communication links are Healthy 13. Generator Breaker is Open 14. Auxiliaries are healthy and Fuel System Faults are Reset Cont·d GAS TURBINE ENGINEERING - FES Cont·d HYDERABAD 5 ¶READY TO START· displayed Operator presses ´STARTµ then ¶Execute· 1. Start Counter is incremented. 2. AC Lube Oil Pump is started, if not already started. 3. Ratcheting Motor is started & Starting Jaw Clutch is engaged (if unit is ¶Off Cool down·) 4. Master Protective System Energizes (L4) ´STARTINGµ Displayed 1. Auxiliary Hydraulic Pump started 2. Diesel Engine is started. It idles for 2 min. 3. Diesel Engine accelerates to its intermediate speed 4. After the diesel warm up time Hydraulic Ratchet pump Starts and carries out continuous ratchet 4. Turbine Breaks away and the Ratchet pump stops GAS TURBINE ENGINEERING - FES 6 HYDERABAD Cont·d ´CRANKINGµ Displayed 1. Turbine reaches cranking speed (about 19%). 2. The Turbine is purged for 5 min. 3. Turbine Purge Timer times out. ´FIRINGµ Displayed 1. Ignition Relay is energised (2TVX. Spark Plugs are energised 2. 60 sec Firing Timer is started. GAS TURBINE ENGINEERING - FES NO HYDERABAD On Liquid YES 7 Permissible for SRV & GCV enabled Energises Liquid Fuel Trip Solenoid (20 FL) Energises Fuel Pump Clutch Solenoid (20 CF) Permissive for Fuel Bypass valve to operate as established by the digital command FQROUT Starts Booster Atomizing Air Compressor Fuel Stroke Reference (FSR) is set to Firing Value Opening of GCV / closing of Bypass valve depends on this. Flame is detected in 2 out of 4 scanner and is steady for 2 secs NO ´Failure to Igniteµ alarm appears Turbine on Crank Mode YES FSR cuts back to WARM-UP value. ´WARM UPµ displayed GAS TURBINE ENGINEERING - FES Cont·d HYDERABAD 8 Warm Up Timer starts 60 seconds). Compartment vent Fans started. Fired Starts Counter incremented. Fired Hours timer energised. After warm-up time, Diesel Engine Accelerates to its full speed FSR is increased at a predetermined rate to accelerate the Turbine. ´ACCELERATINGµ Displayed At approximately 55 to 60% speed, starting Clutch is automatically disengaged. Diesel Engine cuts back to idle speed and is stopped after 5 min cooldown timer. Turbine is now self sustaining and accelerates on its own At ~ 80 % speed, IGV is opened to 57 deg ( 20 TV-IGV solenoid is energised ) At ~ 95 % speed, Compressor Bleed Valves are closed Aux Lube Oil Pump & Aux Hydraulic Pumps are stoped Turbine Exhaust Frame Cooling fans are started (88 TKI & 2) GAS TURBINE ENGINEERING - FES HYDERABAD On GAS Yes 9 Energises Atomizing Air Bypass Solenoid Valve N0 ´ FULL SPEED NO LOAD´ Displayed Enables Manual Raise/Lower of Turbine Speed Reference to Synchronize the Unit. If Auto Synch permissive are OK, Generator and line are present and above minimums, the Control System will modulate FSR to bring Speed to match the station line frequency and closes Generator Breaker when Phase angle is OK. Depending upon Load Mode Selection , Turbine is Loaded to the Reference and load maintained. ´PART LOAD / PRE SELECTED LOAD/ BASE LOAD ´ Displayed GAS TURBINE ENGINEERING - FES 10 HYDERABAD STARTUP CURVE (DIESEL ENGINE) GAS TURBINE ENGINEERING - FES 11 HYDERABAD STARTUP CURVE (STARTING MOTOR) GAS TURBINE ENGINEERING - FES 12 HYDERABAD CHECKS DURING STARTUP Flame is sensed in all Flame Scanners Exhaust Temperatures are uniform and Spread is normal Acceleration is Smooth and Time taken is in line with earlier values Rise in Exhaust Temperature is Uniform Exhaust Temperature profile is OK and Spread Values are within Limits GAS TURBINE ENGINEERING - FES 13 HYDERABAD CHECKS DURING STARTUP Rise in Wheelspace Temperature is Uniform Vibrations are within Limits and as per earlier values Bearing Oil Drain Temperatures are Normal Opening of Jaw Clutch is at approx. at the same Speed as earlier GAS TURBINE ENGINEERING - FES 14 HYDERABAD GAS TURBINE OPERATIONS GAS TURBINE ENGINEERING - FES 15 HYDERABAD PARAMETERS Pressure Temperatures Lube Oil Header Brg. Drains Comp. Inlet Comp. Discharge Exhaust Wheelspace Cooling Water Outlet Lube Oil Hydraulic Oil Trip Oil Comp. Discharge Inlet Air Filter DP Cooling water GAS TURBINE ENGINEERING - FES 16 HYDERABAD PARAMETERS OTHERS GENERATOR Voltage Current Load Stator Temperatures Vibrations Noise, Rubs Startup Time Coast Down Time Fired Starts Fired Hours GAS TURBINE ENGINEERING - FES 17 HYDERABAD OPERATIONAL DIAGNOSTIC Start up Load Hunting Combustion Trouble Lower Loads Higher Temperatures GAS TURBINE ENGINEERING - FES 18 HYDERABAD MACHINE DO¶S & DONT¶S Do not Force any Logic for Startup Do not attempt Subsequent Starts Without Troubleshooting if M/C trips during Startup Record the trends & Analyze present Operation >>Load Vs Exhaust Temperatures >>Load Vs CPD >>Load Vs FSR >>Load Vs Vibration Use trend Data from Mark IV/V to Notice incipient GAS TURBINE ENGINEERING - FES Problems 19 HYDERABAD GAS TURBINE SHUTDOWN GAS TURBINE ENGINEERING - FES 20 HYDERABAD Shut Down Operation Gas turbine Shut Down can be achieved by Two Means Normal or Fired Shut Down Emergency Shut down Manual Emergency Shut Down Protective Emergency Shut Down GAS TURBINE ENGINEERING - FES 21 HYDERABAD Fired Shut Down Normal Shut Down Reduces the Fuel to the Turbine in a Controlled way (up to 20% of speed and shuts of the Fuel Totally)so as to Reduce overall Thermal Shock to Turbine Internals It is Executed by using ³STOP´ Push Button on ³Unit Control Page´ This is the most Preferred Shut Down Mode GAS TURBINE ENGINEERING - FES 22 HYDERABAD GAS TURBINE ENGINEERING - FES 23 HYDERABAD Emergency Shut Down Shuts of the Fuel immediately by closing Fuel Stop Valves Manual Emergency Stop to be used Judiciously Emergency Push Buttons are Provided on -Mark IV/V Panel / Control Desk -The Manual Push Lever on Over Speed Bolt GAS TURBINE ENGINEERING - FES 24 HYDERABAD STANDBY INSPECTION When Unit is not run for a long time Crank the Turbine once in a Fortnight to drive away Moisture Check Battery system, Oil levels etc. GAS TURBINE ENGINEERING - FES 25 HYDERABAD GAS TURBINE PROTECTIONS GAS TURBINE ENGINEERING - FES 26 HYDERABAD Protection System Electrical Protection systems >>Over Speed >>High Exhaust Temperature >>Low Lube Oil Pressure >>Low Trip Oil Pressure >>High Lube Oil Temperature >>Loss of Flame >>High Vibration GAS TURBINE ENGINEERING - FES 27 HYDERABAD Protection Systems Cont¶d... >>Combustion Monitoring >>Customer Trip >>Fire Detection in Compartment Enclosures >>Generator Class µA¶ Trip Mechanical Protections >>Over Speed Bolt >>Trip Out Devices Based on Low Trip Oil >>Manual Emergency Trip Device GAS TURBINE ENGINEERING - FES 28 HYDERABAD Over Temperature Alarm & Trip TTXM TTKOT3 TTRX TTKOT2 A A>B B To Alarm Message & Speed Set Point Lower A A>B B OR TTKOT1 L86MR1 A A>B B LATCH SET RESET To Master Protection Alarm & Trip GAS TURBINE ENGINEERING - FES 29 HYDERABAD Over Temperature Protection TRIP TTXM Temp. Feedback TTKOT2 TTKOT3 TRIP ALARM TTRX(Temp. Control Reference) Compressor Pressure Discharge GAS TURBINE ENGINEERING - FES 30 HYDERABAD Vibration protection Standard Vibration Measurements used for Tripping GT are Velocity Type on Bearing Housing Alarm setting = 0.5´ / sec Trip setting = 1.0´ / sec Total System is Tested for Integrity during Turbine Shut Down by Mark IV / V Panel GAS TURBINE ENGINEERING - FES 31 HYDERABAD Vibration Protection If All Gas Turbine Sensors are Disabled or Faulty OR If All Generator Sensors are are Disabled or Faulty T GROUP DISABLED ALARM & TRIP If 3 or more GT Sensors are Disabled or Faulty OR If 2 or more Generator sensors Disabled or faulty GAS TURBINE ENGINEERING - FES T START INHIBIT 32 HYDERABAD Vibration Trip Adjacent Sensor OPTVTD Any Trip and if any Adj. Pair Disabled or Alarmed Any Trip and any Alarm from other Sensor Any Trip and if 2 or more Sensors are Disabled OR T SET AND LATCH RESET L39VGTT Gas Turbine Trip RESET Any Trip and Any Alarm from another Sensor OR Any Trip if 2 Sensor Inputs or Disabled T SET AND LATCH RESET L39VGT Generator Trip GAS TURBINE ENGINEERING - FES 33 HYDERABAD Vibration Trip Contd.. L39VGTT OR L39VGT L39VT HIGH VIBRATION TRIP T Vibration Differential Alarm BB 1 BB 2 LK39DIFF + _ A A >B B OR OTHER SIMILAR GROUPS GAS TURBINE ENGINEERING - FES 34 HYDERABAD Combustion Monitoring Exhaust Temperature Spreads are the Result of Uneven Combustion in all the Combustion Chambers Combustion Monitoring is Built in Mark IV/V Combustion Monitoring is Enabled after Machine Reaches FSNL GAS TURBINE ENGINEERING - FES 35 HYDERABAD Exhaust Spread Calculations Actual Spread ))TTXSP1 : Highest - Lowest TC ))TTXSP2 : Highest - 2 nd Lowest TC ))TTXSP3 : Highest - 3 rd Lowest TC Allowable Spread ( TTXSPL ) = 0.145 TTXC - 0.08 CTDA + 30 deg F During Dynamic Conditions the Allowable Spread is Increased GAS TURBINE ENGINEERING - FES 36 HYDERABAD Trip Conditions 1. TTXSP1 > TTXSPL and TTXSP2 > 0.8 TTXSPL and The two Lowest TCs are adjacent 2. TTXSP1 > 5 TTXSPL and TTXSP2 > 0.8 TTXSPL and The 2nd and 3rd Lowest TCs are Adjacent 3. All Spreads are > TTXSPL Trip : Any of the above Conditions exists for more than 9 Sec GAS TURBINE ENGINEERING - FES