2909127-GAS-TURBINE-5

GAS TURBINE ENGINEERING - FESGAS TURBINE ENGINEERING - FES

11

HYDERABAD

GAS TURBINE

STARTUP


22

HYDERABAD

OBJECTIVES

To smoothly start,Accelerate and bring the Gas Turbine to full Speed No LoadCondition


33

HYDERABAD

PRE START UP CHECKS• All MCC modules are switched ‘ON' and are kept on ‘Auto’• Lube Oil Level is OK & Oil temp. normal • Select “Cooldown 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


44

HYDERABAD

Normal Start

Operator selects “CRANK / FIRE /AUTO” then ‘Execute’

Protections System checks Ready to Start Permisives:01. Generator Lockout Relay is Reset02. Turbine is at Zero Speed03. Overspeed Bolt is Reset04. Flame is not Detected in all Scanners05. Compressor Bleed valves are Open06. ‘OFF ’ is not Selected07. IGV is Closed08. Master protective ‘4’ Logic is Reset09. <R> <S> and <T> Master Protectives agree 10. Emergency Lube Oil Pump Voltage is Normal11. Diesel Test is not in Progress12. <R> <S> and <T> Communication links are Healthy 13. Generator Breaker is Open14. Auxiliaries are healthy and Fuel System Faults are Reset

Cont’d

Select “UNIT CONTROL” Display


55

HYDERABAD ‘READY TO START’ displayed

Operator presses “START” 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)

Cont’d

“STARTING” Displayed1. Auxiliary Hydraulic Pump started2. Diesel Engine is started. It idles for 2 min.3. Diesel Engine accelerates to its intermediate speed4. After the diesel warm up time Hydraulic Ratchet pump Starts and carries out continuous ratchet4. Turbine Breaks away and the Ratchet pump stops


66

HYDERABAD

“CRANKING” Displayed

1. Turbine reaches cranking speed (about 19%).2. The Turbine is purged for 5 min.3. Turbine Purge Timer times out.

“FIRING” Displayed

1. Ignition Relay is energised (2TVX. Spark Plugs are energised2. 60 sec Firing Timer is started.

Cont’d


77

HYDERABAD

NO OnLiquid

YESPermissible 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 FQROUTStarts 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 in2 out of 4 scanner and is steady for 2 secs

NO YES

“Failure to Ignite” alarm appears Turbine on Crank Mode

FSR cuts back toWARM-UP value.

“WARM UP” displayed


88

HYDERABADWarm 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 speedFSR is increased at a predetermined rate to accelerate the Turbine.

“ACCELERATING” DisplayedAt approximately 55 to 60% speed, starting Clutch is automaticallydisengaged. Diesel Engine cuts back to idle speed and is stopped after5 min cooldown timer.Turbine is now self sustaining and accelerates on its ownAt ~ 80 % speed,IGV is opened to 57 deg ( 20 TV-IGV solenoid is energised )At ~ 95 % speed,Compressor Bleed Valves are closedAux Lube Oil Pump & Aux Hydraulic Pumps are stopedTurbine Exhaust Frame Cooling fans are started (88 TKI & 2)

Cont’d


99

HYDERABAD

OnGAS

YesEnergises Atomizing AirBypass Solenoid Valve

N0“ FULL SPEED NO LOAD“ Displayed

Enables Manual Raise/Lower of Turbine Speed Reference toSynchronize 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.

“PART LOAD / PRE SELECTED LOAD/ BASE LOAD “ Displayed

Depending upon Load Mode Selection , Turbine is Loaded to the Reference and load maintained.


1010

HYDERABAD

STARTUP CURVE (DIESEL ENGINE)STARTUP CURVE (DIESEL ENGINE)


1111

HYDERABAD

STARTUP CURVE (STARTING MOTOR)STARTUP CURVE (STARTING MOTOR)


1212

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


1313

HYDERABAD

• 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

CHECKS DURING STARTUP


1414

HYDERABAD

GAS TURBINE

OPERATIONS


1515

HYDERABAD

PARAMETERS

Pressure

• Lube Oil• Hydraulic Oil• Trip Oil• Comp. Discharge• Inlet Air Filter DP• Cooling water

Temperatures

• Lube Oil Header• Brg. Drains• Comp. Inlet• Comp. Discharge• Exhaust• Wheelspace• Cooling Water Outlet


1616

HYDERABAD

OTHERS

• Vibrations• Noise, Rubs• Startup Time• Coast Down Time• Fired Starts• Fired Hours

GENERATOR

• Voltage• Current• Load• Stator Temperatures

PARAMETERS


1717

HYDERABAD

OPERATIONAL DIAGNOSTIC

• Start up• Load Hunting• Combustion Trouble• Lower Loads• Higher Temperatures


1818

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 Problems


1919

HYDERABAD

GAS TURBINE

SHUTDOWN


2020

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


2121

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 “STOP” Push Button on “Unit Control Page”

• This is the most Preferred Shut Down Mode


2222

HYDERABAD


2323

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


2424

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.


2525

HYDERABAD

GAS TURBINE

PROTECTIONS


2626

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


2727

HYDERABAD

Protection Systems Cont’d...

>>Combustion Monitoring>>Customer Trip>>Fire Detection in Compartment Enclosures>>Generator Class ‘A’ Trip

• Mechanical Protections>>Over Speed Bolt>>Trip Out Devices Based on Low Trip Oil>>Manual Emergency Trip Device


2828

HYDERABAD

Over Temperature Alarm & TripOver Temperature Alarm & TripTTXM A

A>BB

To Alarm Message & Speed Set Point Lower

A A>BB

A A>BB

OR

LATCHSET

RESET

TTKOT3

ToMaster

TTRX

TTKOT2

L86MR1 ProtectionAlarm &Trip

TTKOT1


2929

HYDERABAD

Over Temperature Protection

TTXMTemp.Feedback

TRIP

Compressor Pressure Discharge

TTKOT3

TTKOT2

TRIP

ALARM

TTRX(Temp. ControlReference)


3030

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


3131

HYDERABAD

Vibration ProtectionIf All Gas Turbine Sensors

are Disabled or Faulty

If All Generator Sensors are are Disabled or Faulty

If 3 or more GT Sensors are Disabled or Faulty

If 2 or more Generator sensors Disabled or faulty

OR

OR

T

T

GROUPDISABLEDALARM &TRIP

STARTINHIBIT


3232

HYDERABAD

Vibration TripOPTVTD

Any Trip and if any Adj.Pair Disabled or Alarmed

Any Trip and any Alarmfrom other Sensor

Any Trip and if 2 or moreSensors are Disabled

Any Trip and Any Alarmfrom another Sensor

Any Trip if 2 SensorInputs or Disabled

Adjacent Sensor

OR

OR

RESET

T

T

SETANDLATCH

RESET

SETANDLATCH

RESET

L39VGTT

Gas TurbineTrip

L39VGT

GeneratorTrip


3333

HYDERABAD

Vibration Trip Contd..L39VGTT

L39VGTOR

L39VT

HIGHVIBRATIONTRIP

BB 1

BB 2

A A > BB OR

T

LK39DIFF

OTHER SIMILARGROUPS

VibrationDifferentialAlarm

+_


3434

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


3535

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


3636

HYDERABAD Trip Conditions1. 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 Adjacent3. All Spreads are > TTXSPLTrip : Any of the above Conditions exists for more than 9 Sec

Documents

2909127-GAS-TURBINE-5