1) The document describes the governing system and components of a steam turbine. It includes throttle controlled governing and discusses advantages like avoiding overspeeding and adjusting droop. 2) It lists the different oils used like trip oil, auxiliary trip oil, and control oil and describes what each oil is used for like tripping the stop valve or hydraulic governing. 3) The main elements of the governing system are described including remote trip solenoids, main trip valve, speeder gear, and follow-up piston valves that control steam flow and turbine speed.

2.  THROTTLE CONTROLLED GOVERNING.
 THE GOVERNING SYSTEM HAS GOT FOLLOWING
ADVANTAGES:
1)AVOIDS OVERSPEEDING OF TURBINE DURING LOAD
THROW OFFS.
2)ADJUSTMENT OF DROOP IN FINE STEP,EVEN DURING
ON-LOAD OPERATION.
3) FOR SMOOTH RUNNING OF THE STEAM TURBINE AT
VARYING LOADS.
OIL FROM MOT BEING USED AS THE SOURCE OF
GOVERNING OIL 220MW STEAM TURBINE HOWEVER
FRF FLUID BEING USED AS THE GOVN. OIL IN 500 MW
STEAM TURBINE

3. • TRIP OIL
• AUXILIARY TRIP OIL
• SECONDARY OIL
• AUXILIARY SECONDARY OIL
• START-UP OIL
• AUXILIARY- START UP OIL
• PRIMARY OIL
• CONTROL OIL

4.  TRIP OIL –FOR STOP VALVE
 AUXILIARY TRIP OIL-FOR PROTECTION
DEVICES
 SECONDARY OIL-FOR CONTROL VALVE
 AUXILIARY SECONDARY OIL-HYDRAULIC
GOVERNING.
 PRIMARY OIL –FOR SENSING SPEED
 START UP OIL –FOR RESETTING THE STOP
VALVE AND FOR RELEASING THE CONTROL
VALVE

5.  AUXILIARY START UP OIL –FOR RESETTING
PROTECTION DEVICES

6. THE MAIN ELEMENTS OF GOVERNING SYSTEM:
1) REMOTE TRIP SOLENOIDS(RTS)
2) MAIN TRIP VALVE(TURBINE TRIP GEAR)
3) STARTING AND LOAD LIMITING DEVICE
4) SPEEDER GEAR(HYDRAULIC GOVERNOR)
5) AUX. FOLLOW-UP PISTON VALVES

7. 6) FOLLOW- UP PISTON VALVES
7) ELECTRO-HYDRAULIC CONVERTER
8) SOLENOIDS FOR LOAD SHEDDING RELAY
9) TEST VALVE
10) OIL SHUT OFF VALVE
11) HYDRAULIC PROTECTION DEVICES

8.  REMOTE TRIP SOLENOID OPERATED VALVES
ARE TWO IN NUMBER AND FORM A PART OF
TURBINE PROTECTION SYSTEM
 DURING NORMAL OPERATION OF TURBINE
,SOLENOIDS REMAIN DE-ENERGISED.IN THIS
CONDITION THE CONTROL OIL FROM THE
RACK IS FREE TO PASS THROUGH THEM TO
THE MAIN TRIP VALVES
 WHENEVER ANY ELECTRICAL TRIP
COMMAND IS INITIATED OR TURBINE IS
TRIPPED MANUALLY FROM LOCAL OR UCB,
THE SOLENOID VALVES GET ENERGISED.

9. • IN THIS CONDITION THE DOWNSTREAM OIL SUPPLY
AFTER THE RTS GETS CONNECTED TO THE DRAIN

10.  MAIN TRIP VALVES (TWO IN NUMBER) ARE THE
MAIN TRIP GEAR OF THE TURBINE
PROTECTION CIRCUIT.ALL TURBINE TRIPPING
TAKE PLACE THROUGH THESE VALVES.
 THE CONTROL OIL FROM REMOTE TRIP
SOLENOIDS FLOWS INTO TRIP OIL AND
AUXILIARY TRIP OIL.
 TRIP OIL IS SUPPLIED TO STOP VALVES
AUXILIARY SECONDARY OIL CIRCUIT AND
SECONDARY OIL CIRCUIT.

11. • THE AUXILIARY TRIP OIL FLOWS IN A CLOSED
LOOP FORMED BY MAIN TRIP VALVES AND TURBINE
HYDRAULIC PROTECTIVE DEVICES. I.E. OVERSPEED
TRIP DEVICE,LOW VACUUM TRIP DEVICE,AND
THRUST BEARING TRIP DEVICE.
• WHENEVER CONTROL OIL PRESSURE DROPS OR
ANY OF THE HYDRAULIC PROTECTIVE DEVICES ARE
ACTUATED,THE MAIN TRIP VALVES ARE
TRIPPED,THE TRIP OIL IS DRAINED RAPIDLY
THROUGH THE MAIN VALVES,CLOSING TURBINE
STOP AND CONTROL VALVES.

12.  USED FOR RESETTING THE TURBINE AFTER TRIPPING,FOR
OPENING THE STOP VALVES AND RELEASING THE
CONTROL VALVES FOR OPENING.
 CONSISTS OF A PILOT THAT CAN BE OPERATED EITHER
MANUALLY BY HAND WHEEL OR BY MEANS OF REMOTE.
 AT 0 POSITION OF THE PILOT VALVE ALL THE PROTECTION
GET RESET AND THE SPEEDER GEAR BELLOW GETS
COMPRESSED ,AVOIDING THE DEVELOPMENT OF
SECONDARY OIL PRESSURE
 WHILE OPENING THE VALVE THE START UP OIL GETS
DRAINED ,THUS OPENING THE STOP VALVE ESV OPENS AT
AROUND 42%OF THE POSITION OF STARTING DEVICE.

13.  THE TRIP IS SUPPLIED TO THE FOLLOW UP
PISTON VALVES THROUGH ORIFICES AND
FLOWS IN THE SECONDARY OIL PIPING TO
CONTROL VALVES.
 THE SECONDARY OIL PRESSURE DEPENDS
UPON THE POSITION OF THE SLEEVES OF
FOLLOW UP PISTON.
TRIP OIL
FOLLOW
UP PISTON
SECONDARY
OIL

14.  TWO AUXILIARY FOLLOW UP PISTON ARE
CONNECTED IN PARALLEL AND THE TRIP OIL
IS SUPPLIED TO THEM THROUGH ORIFICE.
 THE AUXILIARY SECONDARY OIL PRESSURE
DEPENDS UPON THE POSITION OF THE SLEEVE
OF THE AUXILIARY FOLLOW -UP PISTON.

TRIP OIL
AUXILIARY
FOLLOW UP
PISTON
AUXILIARY
SECONDARY
OIL

15.  CONSISTS OF TWO STRIKERS
ECCENTRICALLY MOUNTED ON THE
MAIN TURBINE SHAFT AND RESTING
AGAINST THE SPRING FORCE.
 IN CASE OF OVERSPEEDING OF THE
TURBINE I.E 10-11% OVERSPEEDING THE
STRIKERS GET OUT OF THE SPRING FORCE
AND HIT THE PAWLS.THIS ULTIMATELY
GIVES COMMAND FOR CONNECTING THE
AUXILIARY TRIP OIL TO DRAIN THEREBY
DEPRESSURISING IT

16.  TO INTERRUPT THE SUPPLY OF OIL TO ALL
CONTROL &PROTECTION DEVICES
IMMEDIATELY IN CASE OF FIRE DUE TO
LEAKAGE IN CONTROL OIL SYSTEM.
 OPERATED BY HYDRAULIC OIL

17.  TO OPERATE THE CONTROL VALVES TO GIVE
THE APPROPRIATE TURBINE SPEED
THROUGHOUT FOR THE PARTICULAR LOAD
CONDITION

19. HEALTHINESS OF FOLLOWING COMPONENTS IS
CHECKED ONLINE (WITHOUT TRIPPING OF TURBINE)
 PROTECTION DEVICES
- FUNCTIONING OF REMOTE TRIP SOLENOID
- FUNCTIONING OF OVERSPEED TRIP FLYBOLTS
- FUNCTIONING OF HYDRUALIC LOW VACUUM TRIP
- FUNCTIONING OF THRUST BEARING TRIP
 TURBINE STOP & CONTROL VALVE
- FREE MOVEMENT OF ALL HP / IP STOP VALVES
- FREE MOVEMENT OF ALL HP / IP CONTROL VALVES

20.  ATT FOR PROTECTION DEVICES
- TWICE IN A WEEK
 ATT FOR TURBINE STOP & CONTROL VALVE
- ONCE IN A MONTH
ATT FOR PROTECTION DEVICES IS CONDUCTED AT
FULL LOAD CONDITION WHEREAS FOR TURBINE STOP
& CONTROL VALVE IT IS CONDUCTED AT PART LOAD
CONDITION.

21.  LINK BETWEEN THE ELECTRICAL AND THE
HYDRAULIC PART OF THE TURBINE CONTROL
SYSTEM
 CONVERTS THE SIGNAL FROM THE
ELECTRICAL CONTROLLER INTO HYDRAULIC
SIGNAL AND AMPLIFIES THEM BEFORE
TRANSMITTING THEM TO THE ACTUATING
DEVICES.