GAS TURBINEGAS TURBINESTARTUP/ SHUTDOWN SEQUENCESTARTUP/ SHUTDOWN SEQUENCE

WHAT IS SEQUENCING?

1. SEQUENTIAL CIRCUITS ARE PROVIDED TO SEQUENCE THE TURBINE, THE GENERATOR, THE STARTING DEVICE AND THE AUXILLIARIES DURING STARTUP, RUNNING, SHUTDOWN AND COOLDOWN.

2. MONITORS THE PROTECTIVE SYSTEM AND OTHER MAJOR SYSTEMS SUCH AS THE FUEL, HYDRAULIC LUBE OIL SYSTEMS AND GENERATOR LOGIC SIGNALS TO PERMIT THE GT TO START AND STOP IN A PRESCRIBED MANNER

3. LOGIC SIGNALS INCLUDE SPEED LEVEL SIGNALS, SPEED SET-POINT CONTROL, LOAD CAPACITY SELECTION, FUEL SELECTION, STARTING MEANS AND THE TIMERS

NORMAL STARTING PROCEDURES NORMAL STARTING PROCEDURES AND SEQUENCESAND SEQUENCES

ASSUMPTIONS

1. INITIAL STARTUP AND CHECKOUTS AND CALIBRATIONS DONE

2. AC AND DC POWER AVAILABLE FOR ALL PUMPS, MOTORS, HEATERS AND CONTROL

3. ALL ANNUNCIATOR DROPS (ALARMS) ARE CLEARED

4. TURBINE COOLDOWN OR STANDBY MODE READY FOR NORMAL OPERATION

STARTING SEQUENCESSTARTING SEQUENCES

1) SELECT “NORMAL” DISPLAY

CRT DISPLAYS :

• SHUTDOWN STATUS

• NOT READY TO START

• OFF COOLDOWN

• SELECT OFF

2) SELECT “AUTO” AND THEN EXECUTE

CRT DISPLAYS :

• STARTUP STATUS

• READY TO START

• SELECT AUTO

SEQUENCES:SEQUENCES:

FOLLOWING PROTECTION SYSTEMS CHECKS FOR THE “READY TO START” PERMISSIVE ARE CARRIED OUT

1. TURBINE IS AT ZERO SPEED

2. LUBE OIL TEMP IS NORMAL

3. FLAME NOT DETECTED IN ALL SCANNERS

4. “OFF” IS NOT SELECTED

5. FUEL VALVE IS CLOSED AND LOCKOUT IS RESET

6. COMPRESSOR BLEED VALVE IS OPEN

7. IGV IS CLOSED

8. OVERSPEED VOLT IS RESET

9. BEARING AND SEALING VALVE IS OPEN

10. MASTER PROTECTIVE “L4” LOGIC IS RESET

11. R, S, T MASTER PROTECTIVE AGREE

12. EOP VOLTAGE NORMAL

13. CUSTOMER PERMISSIVE TO START ARE OK

14. DIESEL ENGINE NOT IN “TEST”

15. OFF- LINE DIAGNOSTICS NOT IN PROGRESS

16. R, S, T COMMUNICATION LINKS NOT HEALTHY

17. GENERATOR BREAKER OPEN

18. GENERATOR LOCK-OUT RELAY IS RESET

19. DIESEL ENGINE WARM-UP TIMER IS RESET

20. MULTIPLE STARTS COUNTER RESET

21. FUEL SELECTION ON TOTAL LIQUID OR GAS FUEL SYSTEMS FAULTS RESET

B) ALL TRIP FUNCTIONS ARE CHECKED TO BE IN “NOT TRIPPED” STATE AND RESET. ONLY THEN “ NOT READY TO START” GOES OFF

3) A. SELECT “START” ON THE MASTER CONTROL SELECTOR

CRT DISPLAYS :

• “STARTUP STATUS”

• “READY TO START”

• SELECT AUTO START”

SEQUENCES: FOLLOWING START COMMAND PERMISSIVE ARE CHECKED BY THE PROTECTION SYSTEM

1. BASE, PEAK OR PRESELECTED LOAD IS NOT SELECTED

2. “C” COMMUNICATOR LINK IS HEALTHY AND RESET

3. AUXILLIARY SERVOS CHECKS ARE OK

4. STARTING DEVICE TRIP IS RESET

5. MULTIPLE RESTART IS RESET

6. EMERGENCY PUSH BOTTON IS RESET

7. STOP SEQUENCE IS NOT IN PROGRESS

8. GENERATOR BREAKER RE-CLOSING TIME IS RESET

9. CONTROL NOT IN OFF

3) B. UNIT AUXILLIARIES WILL BE STARTED TO ESTABLISH LUBE OIL PRESSURE

CRT DISPLAYS :

• “SEQUENCE IN PROGRESS” (APPEARS IN ADDITION TO OTHERS)

SEQUENCE

AOP (88HA) IS STARTED

3) C. IF STARTING CLUTCH IS NOT ENGASED, THE RETCHETING WILL OPERATE UNTILL THE CLUTCH ENGASES. WITH THE JAW CLUTCH ENGASED, THE LUBE OIL PRESSURE AND ALL PERMISSIVES (L4) SATISFIED

CRT DISPLAYS :

• “STARTUP STATUS”

• “STARTING”

• “SELECT AUTO START”

SEQUENCE

1. STARTING CLUTCH (20CS) ENERGISES

2. JAW CLUTCH 33CS

3. HYDRAULIC RATCHET PUMP (88HR) STARTS

4. AUX HYDRAULIC PUMP (88HQ) STARTS

5. “MANUALLY INITIATED STARTS” COUNTER INCREMENTED

6. TURBINE SPEE FERERENCE (TNR) IS PRESETTO START/ SHUTDOWN (60%)

7. MASTER PROTECTIVE SYSTEMS L4 ENERGISES

4) A. DIESEL ENGINE IS CRANCKED AND WHEN ITS LUBE OIL PRESSURE IS NORMAL, THE TOTAL STARTS COUNTER IS INCREMENTED BY ONE

CRT DISPLAYS :

• NO CHANGE

SEQUENCE

1. DIESEL ENGINE STOP VALVE (20DV) ENERGISES

2. D.E. CRANCKING (88DS) MOTOR STARTS FOR 5 SEC

3. D.E. STARTS AND D.E. NORMAL LUBE OIL PRESSURE (63QD) PICKS UP

4. “TOTAL STARTS” COUNTER IS INCREMENTED BY ONE

4) B. THE TYPE OF FUEL USED IS ESTABLISHED i.e. LIQUID/ GAS

CRT DISPLAYS :

• NO CHANGE

SEQUENCE

1. LIQUID FUEL PURGE SOLENOID VALVE (20PL) IS DEENERGISED ( FOR LIQUID)

OR

2. GAS FUEL TRIP SERVO SOLENOID (20FG) IS ENERGISED AND (20PL) IS ENERGISED

5) THE D.E. STARTS AND WILL RUN AT IDLE SPEED (650 RPM) FOR 2 MINUTE TO WARMUP. AT THE END OF WARMUP THE RATCHET OPERATES CONTINOUSLY AND THE D.E. ACCELERATES

CRT DISPLAYS :

• NO CHANGE

SEQUENCE

1. D.E. REACHES ITS IDLE (MIN) SPEED OF 650 RPM (20DA-1)

2. D.E. GOES ON 2 MIN WARPUP

3. D.E. ACCELARATING SOLENOID (20DA-2) IS ENERGISED

4. RATCHET STARTS CONTINOUS OPERATION

6) THE D.E. ACCELERATES TO 1800 RPM AND THE TURBINE BREAKS AWAY

CRT DISPLAYS :

• “STARTUP STATUS”

• “STARTING”

• “14 HR”

SEQUENCE

1. 20DA-2 IS ENERGISED

2. TURBINE BREAKS AWAY (14HR) AT 10 RPM

7) WHEN THE TURBINE REACHES 20% SPEED i.e. 1000 RPM, THE MIN SPEED SIGNAL RELAY “14HM” IS ENERGISED AND THE TURBINE REACHE CRANKING SPEED

CRT DISPLAYS :

• 14 HR CHANGES TO 14HM

• “CRANKING”

SEQUENCE

1. STARTING CLUTCH SOLENOID (20CS) DE-ENERGISED

2. HYDRAULIC RATCHET PUMP 88HR IS SHUT-DOWN

3. JAW CLUTCH IS HELD ENGASED BY THE TORQUE OF D.E.

4. D.E. REACHES DIESEL CRANKING SPEED (1400 RPM)

5. D.E. ACCELERATING SOLENOID (20DA-2) IS DE-ENERGISED

6. D.E. CRANKING SPEED (14DC) DROPS OUT

7. D.E. CRANKING SPEED LOCKING SOLENOID (20DA-1) ENERGISES AND SPEED STAYS CONSTANTS

8. MIN SPEED SIGNAL RELAY (14HM) IS ENERGISED

8) AT THE MIN FIRE SPEED THE TURBINE WILL HOLD CRANKING SPEED UNTILL THE TURBINE PURGE TIMER HAS COMPLETED ITS CYCLE

CRT DISPLAYS :

• NO CHANGE

SEQUENCE

1. THE TURBINE PURGE TIMER (L2TV) IS STARTING CLUTCH SOLENOID (20CS) DE-ENERGISED

2. IGNITION RELAY (L2TVX) IS ENERGISED

3. SPARK PLUGS (95SP) ARE ENERGISED

9) AFTER THE PURGE TIMER HAS COMPLETED THE FIRING TIMER IS INITIATED AND FSR SET TO FIRING VALUE

CRT DISPLAYS :

• “STARTUP STATUS”

• “FIRING”

• “STARTUP CONTROL”

SEQUENCE

1. TURBINE PURGE TIMER TIMES OUT

2. 60 SEC FIRING TIMER IS STARTED

3. IN CASE OF LIQUID FUEL

- LIQUID FUEL TRIP SOLENOID (20FL) IS ENERGISED

- LIQUID FUEL PUMP CLUTCH (20CF) IS ENERGISED

- PERMISSIVE FOR FUEL BYPASS VALVE TO OPERATE AS PER

FQROU (FSR)

4. IN CASE OF GAS FUEL

- PERMISSIVE FOR SPEED RATIO VALVE TO OPEN IS ENABLED

- PERMISSIVE FOR GCV TO OPEN IS ENABLED

5. FSR IS RAISED TO FIRING LEVEL

10) IF FLAME IS DETECTED IN TWO OR MORE SCANNERS & THE FLAME IS STEADY FOR TWO SEC THEN FSR IS LOWERED TO WARMUP LEVEL

CRT DISPLAYS :

• “FLAME A#B#C#D”“

• “STARTUP STATUS”

• WARMING UP”

SEQUENCE

1. FLAME IS DETECTED IN COMBUSTION CHAMBER

2. FSR IS LOWERED TO WARMUP VALUE

3. WARMUP TIMER (L2W) STARTS TIMING 60 SEC

4. FIRING TIMER (2F) TIMES OUT

5. TURBINE COMPTMENT VENT FANS (88BT) IS STARTED

6. FIRED HOURS TIMER IS ENERGISED

7. FIRED STARTS COUNTER IS INCREMENTED BY ‘1’

11) IF THE FLAME GOES OUT OR ONLY ONE FLAME IS ESTABLISHED DURING THE 60 SEC TIME FSR IS SET BACK TO THE FIRING VALUE TO ATTEMPT TO FIRE GAIN. SELECT “CRANK” AND THEN “EXECUTE” RE-SELECTING “AUTO” WILL CAUSE THE IGNITION SEQUENCE TO REPEAT AFTER THE PURGE TIMER HAS TIMES OUT

CRT DISPLAYS :

• “CRANK“

• “FAILURE TO IGNITE”

SEQUENCE

• OPERATOR PRESSES “CRANK” AND THEN “EXECUTE”

• OPERATOR PRESSES “AUTO” OR “FIRE” THEN “EXECUTE”

• TURBINE PURGE TIMER IS STARTED FOR 60 SEC AIR PURGING

12) AT THE END OF THE WARMUP PERIOD AND THE FLAME ESTABLISHED, FSR IS INCREASED AT A PREDETERMINED RATE ON EXPONENTIAL RAMP TO “FSR ACCELERATE” LIMIT.

CRT DISPLAYS :

• “ACCELERATING“

SEQUENCE

• WARMUP TIMER L2W TIMES OUT

• D.E. ACCELERATING SOLENOID (20DA-2) IS ENERGISED

• D.E. LOCKING SOLENOID (20DA-2) IS DE-ENERGISED

• FSR RAISED TO ACCELERATING LIMIT

13) THE TURBINE THEN ACCELERATING TO THE ACCELRATING SPEED SET POINT i.e. 50% SPEED (2500 RPM & SPEED LEVEL 14HA)

CRT DISPLAYS :

• “14HA“

SEQUENCE

• TURBINE ACCELERATING TO THE ACCELERATING SPEED AND SPEED SIGNAL RELAY 14HA IS ENERGISED.

14) THE TURBINE CONTINUES TO ACCELERATE AND AT 60% SPEED D.E. DISENGASES AND IS SHUTDOWN. BEFORE D.E. SHUTDOWN IT WILL COOLDOWN AT IDLE SPEED. THE TURBINE REACHES THE STARTUP PRESET TNR OF 60% AND SPEED CONTROL TAKES OVER TO CONTINUE ACCELERATION

CRT DISPLAYS :

• “STARTUP CONTROL CHANGES TO SPEED CONTROL”

SEQUENCE

• JAW CLUTCH (33CS) DISENGASES

• D.E. ACCELERATING SOLENOID (20DA-2) IS DE-ENERGISED

• D.E. COOLDOWN TIMER (L62DE) STARTS FOR 5 MIN TIME OUT

15) THE TURBINE IN THE ACCELERATING MODE IS ACCELERATED TO ITS OPERATING SPEED OF 97% SPEED AT WHICH OPERATING SPEED SIGNAL RELAY 14HS PICKSUP

CRT DISPLAYS :

• “SPEED CONTROL AND 14HS”

SEQUENCE

• SPEED REFERENCE TNR IS RAISED

• OPERATING SPEED RELAY 14HS IS ENERGISED

• IGV SOLENOID VALVE (20TV) ENERGISES TO OPEN

• COMPRESSOR BLEED VALVE CLOSING IS ENEBLED

16) WHEN THE TURBINE HAS REACHED ITS MIN OPERATING, THE TURBINE EXHAUST FRAME COOLING FAN 88TK-1/2 STARTS, AOP AND AHOP STOPS. THE CONTROL SYSTEM GOES THROUGH THE COMPLETE SEQUENCE CHECKS

CRT DISPLAYS :

• “RUN STATUS”

• “COMPLETE SEQUENCE” • “FULL SPEED NO LOAD”

SEQUENCE

• 88TK-1/2 STARTS

• AUX LUBE OIL PUMP (88QA) STOPS

• AUX HYDRAULIC PUMP (88HQ) STOPS

• IF NO GAS FUEL, ATOMISING AIR BYPASS SOLENOID (20AA) IS ENERGISED

• FOLLOWING COMPLETE SEQUENCE PERMISSIVE ARE CHECKED

- JAW CLUTCH DIS-ENGASES

- TURBINE SPEED IS AT OR ABOVE THE OPERATING SPEED

- STOP SEQUENCE IS NOT IN PROGRESS

- TURBINE HAS COMPLETED ITS ATARTUP SEQUENCE (L3)

16) GTG IS TO BE SYNCHRONISED WITH THE SYSTEM AND LOADED ON PART LOAD OR PRESELECTED LOAD

CRT DISPLAYS : • “RUN STATUS” OR

• “PRESELECTED LOAD” OR

• “PART LOAD” OR

• “SPEED CONTROL”

NORMAL SHUTDOWN SEQUENCENORMAL SHUTDOWN SEQUENCE

1) NORMAL SHUTDOWN IS INITIATED BY SELECTING “STOP” ON THE MASTER CONTROL SELECTOR. THIS WILL AUTOMATICALLY UNLOAD THE MACHINE, REDUCE THE SPEED AND SHUTOFF THE FUEL AND INITIATE THE COOLDOWN SEQUENCE AS THE UNIT COMES TO REST

CRT DISPLAYS :

• “STOP SELECTED“

• “UNLOADING”

• “SEQUENCE IN PROGRESS”

• “SHUTDOWN STATUS”

• “FIED SHUTDOWN”

2) THE TURBINE IS AUTOMATICALLY UNLOADED

TILL THE GENERATOR BREAKER TRIP ON REVERSE POWER

CRT DISPLAYS :

• “UNLOADING” GOES OFF

• “FIRED SHUTDOWN” GOES OFF

3) THE TURBINE DECELERATED BELOW THE OPERATING SPEED SET POINT (14HS)

CRT DISPLAYS :

• “14HA” IS DISPLAYED

SEQUENCE • TNR REDUCES BELOW THE OPERATING SPEED LEVEL

(14HS)• 88TK-1/2 STOPD• COMPRESSOR BLEED VALVE OPENS• INLET GUIDE VANES CLOSES• AOP (88HA) STARTS

4) THE TURBINE DECELERATES BELOW THE ACCELERATING SET POINT (14HA) AND THE SHUTDOWN TRIP COMMAND IS GIVEN

CRT DISPLAYS :

• “14HM”

• “COASTING DOWN”

• “STOP SELECT” GOES OFF

SEQUENCE • TURBINE DECELERATES BELOW 14HA• SHUTDOWN TRIP COMMAND L94T IS GIVEN• MASTER PROTECTIVE LOGIC L4 TRIPS FUEL LINES• LIQUID FUEL STOP VALVE 20FL IS DE-ENERGISED • FUEL CLUTCH SOLENOID VALVE 20CF IS DE-ENERGISED• LIQUID FUEL PURGE SOLENOID IS DE-ENERGISED

4) THE TURBINE FINALLY COAST DOWN TO ZERO SPEED AND HYDRAULIC RATCHET STARTS

CRT DISPLAYS :

• “ON COOLDOWN”

• “COASTING DOWN”

SEQUENCE • TURBINE COASTS TO STOP (14HR)• STARTING CLUTCH SOLENOID IS ENERGISED• JAW CLUTCH ENGASES• HYDRAULIC RETCHET STARTS

GAS TURBINEGAS TURBINEDATA SUMMARYDATA SUMMARYGT MODEL SERIES : MS6000

AIR IN : 45 DEG C

ALTITUDE : 36 M

FUEL : NG AND HSD

COMPRESSOR STAGES : 17

TURBINE STAGES : 3

RPM : 5100

PRIMER MOVER : DE

PROTECTION

OVERSPEED

OVER TEMPERATURE

VIBRATION

FLAME DETECTION

SECTIONS OF GAS TURBINESECTIONS OF GAS TURBINE

• DIESEL ENGINE

• ACCESSORY GEAR BOX

• AIR INLET

• COMPRESSOR

• COMBUSTION

• TURBINE

• EXHAUST

• GENERATOR

ACCESSORY GEAR BOXACCESSORY GEAR BOX

• MAIN FUEL OIL PUMP

• MAIN HYDRAULIC OIL PUMP

• MAIN ATOMISING AIR COMPRESSOR

• STARTING CLUTCH

• OVERSPEED TRIP MECHANISM

COMPRESSORCOMPRESSOR

• 17 STAGE

• AXIAL FLOW DESIGN

• FIRST TO TENTH STAGE COMPRESSION

• 11TH TO SENEVTEENTH STAGE DISCHARGE

• IGV AT INLET OF COMPRESSOR

• MAXIMUM CPD 12 BAR

• LOSS OF APD WILL TRIP THE TURBINE AT

4.83 BAR

GT SUPPORT SYSTEMSGT SUPPORT SYSTEMS

• LUBRICATING OIL SYSTEM

• HYDRAULIC OIL SYSTEM

• TRIP OIL SYSTEM

• INLET AIR SYSTEM

• ATOMISING AIR SYSTEM

• LIQUID FUEL SYSTEM

• GAS FUEL SYSTEM

• FIRE PROTECTION SYSTEM

• COOLING AND SEALING AIR SYSTEM