Steam Turbine Startup Shutdown for Training

GENERAL / BRIEF DISCRIPTION

TURBINE IS USED AS A PRIMOVER FOR

(i) TO PRODUCE ELECTICITY. (ii) COMPRESSOR / BLOWER /

PUMPS FOR PROCESS INDUSTRIES.

STEAM TURBINES LOCATED IN GR (i) AT TPS THREE SET (ii) AT FCC – MAB & WGC (iii) AT GRE (AU-IV)- GAS

COMP. (iv) AT CRU- GAS COMP.

TPS TURBINE - BRIEF DATA

MAKE RUSSIAN BHEL

• CAPACITY(MW) 12 12.5• STAGES 17 19• SPEED( RPM) 3000 5400• STEAM INLET (T/HR) 112 150• PROCESS OUT (T/HR) 50 75• CONDENSATE (T/HR) 48 70• GOVERNING SYSTEM HYDO DYNAMIC•LUBRICATION TYPE FORCED LUB.

TURBINE START UP

• PLANNED STARTUP–COLD STARTUP– WARM STARTUP

• EMERGENCY STARTUP– COLD STARTUP– HOT STARTUP

PLANNED STARTUP

1. PRE-START UP ACTIVITY.

2. VACUUME PULLING IN CONDENSER3. ROLLING OF THE TURBINE.4. PROTECTION TESTING. 5. SYNCHRONISATION/ LOADING.6. PROCESS COMMISSIONING.

PRE STARTUP ACTIVITIES

A. GENERALB. STEAM LINEC. CW SYSTEMD. CONDENSERE. LUBRICATING SYSTEMF. BARRING GEAR

GENERAL

• Ensure all L.C’s Returned.• Ensure Surrounding area clean.• Ensure El. Supply to all motors• Ensure boiler is capable of supply steam • Check level of oil in tank• Testing of alarm / Annun. System.• Inform concerned people

STEAM LINEa. Warm up of Main steam inlet line to the

turbine up to the isolation valve.b. Open all drains and vents from the line to

ensure drain out of condensate retained in the line.

c. Allow minimum quantity of steam to flow through the line for warm up and vent out air - steam mixture.

d. Continue warm up slowly till the temperature reaches at least 80 – 85% of the main steam temperature.

e. Close all vent line valves and keep drain valves crack open .

COOLING WATER SYSTEM:

a. Ensure availability of sufficient cooling water supply

b. Build up required level in CW sump .c. Vent out water from CW pump casingd. Start a pump; Observe discharge

Pressure by opening of discharge valve and air venting from condenser.

e. Check auto operation of CW pumps. If healthy put other pump in Auto

CONDENSER

a. Line up cooling water so that minimum cooling water flow is established.

b. check the healthiness of all cooling tower fans.

c. Check the cooling water leakages in to the condenser by testing the conductivity of the condenser.

e. If condensate is available in the hot well start and check the healthiness of the condensate pumps.f. If the condensate is not available in the condenser make up the level

with the DM water. Check the healthiness of the condensate pumps along with Auto start of condensate pumps. g. Maintain the hot well level by keeping the condensate in re- circulation mode.

LUBRICATING SYSTEM

a. Start the centrifuge and keep it running to ensure moisture free lubricating oil in the lube oil tank before starting the lube oil pump. Check the quantity of oil in tank.

b. Line up lube oil coolers.c. Start the auxiliaries lube oil pump

(motor / turbo driven) & check the pressure available at all the bearing inlets.

d. Check the Auto start of emergency lube oil pump.

BARRING GEAR

a. Start the jack oil pump & check its discharge pressure.

b. Ensure turbine & Barring gear motor shaft is stationary and then engage the barring gear attachment lever with the rotor.

c. Start the barring gear motor & ensure the rotor is rotating.

VACUUM PULLING IN THE CONDENSERa. Start supplying sealing steam to the

glands & maintain the pressure just above atmospheric pressure.

b. Start the starting ejector / vacuum pump to build up vacuum in side the condenser.

c. After reaches certain vacuum take the service ejector in to service.

d. On poor vaccum - check the sources of air entering point & arrested; Cond. Pump gland sealing, ejector in let steam pressure, level in condenser.

ROLLING OF TURBINE.

a. Open the Check valve slowly by building up the trip oil pressure and observe the turbine speed.

b. Keep the speed constant for some time to allow for uniform heating of the turbine.

c. Ensure the barring gear is stopped & disengaged when the speed raises.

d. Observe the bearing vibrations & temperatures.

e.Increase the speed by opening steam admission valves at a rate mentioned with respect to the machine start up curve.

f. Care should be taken to increase the turbine speed rapidly when it approaches critical speed.

g.When machine approaches full speed confirm that the main oil pump as taken over by observing AOP motor current.

h.Observe that the governor has started functioning as the machine reached full speed.

i. Stop the AOP & keep in Auto mode.j. Before synchronization check all

the protections of the turbine.k. Close all the turbine drains.l. Synchronize the machine and load

the machine as per start up & loading curve.

m. Ensure that the hot well level & vacuum are maintained after stopping the starting ejector.

Continued

n. Commission all the regenerative feed heating extractions as the load increases.

o. If the machine is designed for controlled extractions warm up all extraction lines & commission the extractions at an appropriate load.

p. Ensure all the operating parameters are with in the limits.

START UP GRAFF FOR COLD/WARM/HOT START UP OF A STEAM TURBINE

0

500

1000

1500

2000

2500

3000

10MIN 20MIN 30MIN 40MIN

COLD<150 0CWARM>250 0CHOT>340 0C

TURBINE HOT START UP

a. When the machine is restarted after few hours of stopping / tripping, is called hot start up.

b. Sequence of activities is similar to cold start up to vacuum pulling.

c. Turbine rolling is to be carried out as per hot start up curve.

d. The loading rate can be faster as per the hot start up curve.

TURBINE PLANNED SHUT DOWN

a. Reduce the machine load in co-ordination with the steam generating unit & generator control room.

b. De-commission the controlled extractions when the machine load is reduced.

c. De-commission the feed heating steam extractions.

d. Extra care should be taken to maintain condenser level while de-commission the extractions.

continued

e. Unload the machine further & finally de-synchronize.

f. Reduce the speed by shutting down the steam valves.

g. Ensure the starting of the AOP during speed reduction from full speed.

h. Cut of gland sealing supply when the condenser vacuum drops down completely

i. Stop the ejector / vacuum pump.

continued

j. Open all drains & vents turbine casing and steam inlet line.

k. When the machine comes to stand still engage the barring gear lever. Start the jack oil pump & then barring gear motor.

l. Continue the barring till the exhaust temperature reduces to ambient.

m. After stopping barring, stop all auxiliaries like AOP, condensate pump, CW pump & fans.

EMERGENCY SHUT DOWN

a. Reduce the load as much fast as possible in co-ordination with steam generating unit & generator control room.

b. De-commission all controlled & uncontrolled extractions.

c. Desynchronize the machine.d. Trip the machine and allow to

come to zero speed.

continued

e. Stop the ejector / vacuum pump & gland sealing supply.

f. Engage the barring gear when the machine comes to zero speed.

g. Start the jack oil pump & barring gear motor.

h. Ensure that the turbine is on barring gear till the exhaust temperature reaches to ambient.

GOVERNING SYSTEM

FUNCTIONS OF GOVERNER: a. TO REGULATE THE SUPPLY OF STEAM TO

THE TURBINE SO THAT THE SPEED & PROCESS PRESSURE REMAIN CONSTANT AT ALL LOAD (DEVIATION CONTROL BETWEEN +4% & -4%) AND PROTECT ON OVER SPEED.

b. SAFE & SMOOTH OPERATION OF A MACHINE.c. TO STOPPED INLET STEAM TO TURBINE ON

OVERSPEED / AXIAL SHIFT / LOW LUBE OIL/ LOW VACUUM / EMERGENCY TRIP

d. PROCESS STEAM PRESSURE AT SET VALUE.

SPEED GOVENOR

• TG –1&2: MAIN OIL PRESSURE IS IT SELF IS

THE SPEED IMPULSE. MORE SPEED – MORE OIL PRESSURE,

LESS SPEED – LESS OIL PRESSURE.

• TG – 3: - PRIMERY OIL PRESSURE IS THE SPEED IMPULSE. - PRIMERY OIL PUMP IS GOVERN WITH MAIN OIL PUMP.

PRESSURE GOVERNOR

• PROCESS STEAM PRESSURE IT SELF IS THE IMPULSE FOR PRESSURE GOVERNER.

• TG –1,2: PROCESS [13 ATA & 1.2 ATA ]

• TG – 3: PROCESS [13 ATA ]

GOVERNING SCHEME IN TG # 1 & 2

GOVERNING SYSTEM IN RUSSIAN TG-SET IS IN BUILT/COMPECT. IT’S MOUNTED ON TOP OF THE TURBINE FRONT BEARING. AND OVER SPEED DEVICE ON SHAFT ALSO PROVIDED ON SAME BLOCK.

SPEED CONTROL: MOP DISCHARGE OIL IS SPEED IMPULSE TO SPEEDER GEAR .

SPEEDER GEAR OUT IMPULSE GOES TO PILOT VALVE,- PILOT VALVE WIIL OPERATE SERVOMOTOR BY BALANCING OIL IMPULSE TO SERVOMOTOR PLUNGER AND FINALLY SERVOMOTOR OPERATE STEAM VALVE/ DIAPHARGM. TO CONTROL SPEED (FREQUENCY) WITHIN + 4% - 4% OF ALL LOAD ON TURBINE.

PROCESS PRESSURE CONTROL: ANY DEVIATION IN PROCESS STEAM WILL CONTROL BY

PROCESS PRESS. SERVOMOTOR SAME LIKE AS SPEED CONROL SERVOMOTOR ACTION.

OVER SPEED : OVER SPEED MECHANISAM WILL OPERATE AT THE TIME OF

OVER SPEEDIG OF TURBINE BY 10% ABOVE THE RATED SPEED OF 3000 RPM. IN THIS GOVERNING OIL WILL DRAIN AND STOP STEAM SUPPLY TO TURBINE.

IN EMERGENCY TRIPPING : GOVERNING OIL WILL BE DRAIN THROUGH SOV .

GOVETING SYSTEM INTURBINE # 3

(SIMENS SR III )GOVERNING CIRCUIT OILS : THE OIL WHICH IS USED IN THE GOVERNING CIRCUIT IS

FURTHER CHARGED IN TO THE FOLLOWING NAMES.(a) PRESSURE OIL : PUMP DISCHARGE ENTER IN TO THE

GOVERNING CIRCUIT.(b) START UP OIL : PRESSURE OIL COMING THROUGH START

UP DEVICE FOR OPENING OF ESV(EERGENCY SHUT OFF VALVE).

(c) TRIP OIL : PRESSURE OIL CONVERTING TOTRIP OIL AFTER PASSING THROUGH TRIPPING DEVICE.

(d) SCONDARY OIL : TRIP OIL PASSING THROUGH THE THROTTLE & AMPLIFIER CHANGES TO SECONDARY OIL.

(e) PRIMERY OIL : PRESSUR OIL IS A SPEED IMPULSE WHICH DISCHARGE COMES FROM IMPELLER & TRANSMIT SIGNAL TO SR- III GOVERNER CAPSUL.

(f) DRAIN OIL : PRESSURE OIL AFTER PASSING THROUGH THE ALL COMPONENTS OF GOV. CIRCUIT DRAINAGE TO BACK.

GOVERNING SCHEME IN TG#3

GOVERNIG SCHEME: (SEE THE DIAGRAM)

THE PRESSURE OIL USED FOR GOVERNING PURPOSE WILL PASS THROUGH GOV. OIL FILTER, SOV(86T), LOW VACUUM PROTCT. DEVICE, LOW LUBE OIL PROTCT. DEVICE, EXTRACT. PRESS. HIGH PROTCT. DEVICE, AND SUPPLIED TO THE TRIPPING DEVICE. THE EMERGENCY OVER SPEED GOVERNOR ACTIVATE ON THE EMERGENCY TRIPPING DEVICE.

THE OIL LEAVING THE TRIPPING OIL DEVICE IS KNOMN AS TRIP OIL. AND WILL BE SUPPLIED TO STARTING DEVICE, EXTRACTION PRESSURE GOVERNER, AND HP HEATER STEAM VALVE.

TRIP OIL SUPPLIED TO THE AMLIFIER & PASSES THROUGH AN ORIFICE AND IS KNOWN AS SECONDARY OIL WHICH IS CONNECTED TO SERVOMOTOR.

THE SPEED OF THE TURBINE WILL BE MAINTAINED CONSTANT BY SRIII GOVERNOR TO WHICH IMPULSEOIL (ORIMERY OIL) BE SUPPLIED BY THE HYDRODYNAMIC GOVERNER(GOV. IMPELLER)

TG#3 GOVERNING OIL SYSTEM FOLLOW-UP ACTION

AFTER SECONDARY OIL SYSTEM

MAXIMUM EXTRACTIONSEC OIL PR. C/V LIFTHP LP HP LP1.5 1.5 0 01.53 1.5 2 02.85 1.8 43

11.53.0 2.1 47 183.2 2.5 54

28.5

MINIMUM EXTRACTIONSEC OIL PR. C/V LIFTHP LP HP LP 1.5 1.5 0 01.53 1.56 1.5 32.0 2.4 18

292.36 3.3 30

452.5 3.6 33.5

45

THANK YOU

PROTECTIONS, SIGNALLING AND ALARMS.

FOR TURBINE # 1&2. TG#3 ACTION

1. Lube oil pr. low 0.5 & 0.4kg/cm2 1.2/. 09kg/cm2 Alarm

2. Lube oil pr. Very low 0.25 kg/cm2 0.65 kg/cm2 TG Trip ,EOP start.

3. Main oil pressure low 7.5, 5.5 kg/cm2 6.5/ 0.80 kg/cm2 Alarm, AOP/TOP I/L

Start

4. Gov/trip oil pr. Very. Low 3.0 kg/cm2 4.5 kg/cm2 Check valves/

Trip oil pr. Very. Low ----- 2.0 kg/cm2 ESV closed

5. Vacuum Low 550 MMHG 550 MMHG Alarm

6. Vacuum Very Low 450 MMHG 450 MMHG Turbine trip

7. Axial force Low/Shift high 12 kg/cm2 +/- 1.0 MM Turbine trip

8. Axial force High / Shift High 20/120kg/cm2 +/- 0.5 MM Alarm

  9. MP steam pr. High/Low 13/10.8 kg/cm2 13 kg/cm2 Alarm

10. MP steam pr. V.High/ Low 15 kg/cm2 15.5 kg/cm2 Safety valve

Blowing

11. LP steam pressure High 2.5 kg/cm2 ----- Alarm & s/v

Blowing

12. HP heater level High ---- Alarm & Heater

Automatic isolated

FOR TG # 1 &2 TG # 3 ACTION13. Condenser level Low ---- 150mm Alarm 14. Condenser level V.High ---- 175mm Alarm & Stand by Pump start on auto

15. Oil tank level Low ---- Alarm

16. Main steam pressure High 37 Kg/cm2 37kg/cm2 Alarm

17. Main steam pressure Low 33 kg/cm2 33kg/cm2 Alarm

18. Main steam Temp.High 4400C 4400C Alarm

19. Main steam Temp. Low 4300C 4300C Alarm

20. Barring gear engage, oil pr. ---- 1.5 Kg/cm2 Alarm

21. Exhaust temp. high 650C 700C Alarm

22. Exhaust temp. very high ---- 1200C Turbine trip

23. Turbine over speed 3300-3360 RPM 6050RPM Turbine trip

24. Jack oil pr. Low. NA 40 Kg/cm2

Alarm

G.I.MOP

HP LP

BELLOW

F.P.

S.M.

S.P.

S.P.

OSTD.

S.M.

ESV

C/VC/V

ASKANIA

OSTK

G

COND.

F

VLT

SOV

GOPLT

EPHT

13 ATA STEAM

HP HTR. ST.

13 ATA ST. IMP.

VAC. IMP.

E

HP STEAM

86T

M

TURBINE # 3 GOVERNING OIL CIRCUIT

DP

PI

PI

TI TITI TI TI TI

PI

PI

PI

TI

TITI

PI

PI

TI

PI

LS

LS

LITI

TI

TI

TI

PIPIPI

TURBINE

GEAR BOX

GENERATOR EXITER

OIL COOLER

OIL FILTER

OIL TANK

AOP

GOVERNING

SYSTEM

MOP

EOP

TI

PI

DP

PS PSPS

PS

LS

LI

EOP AOP

TEMPERATURE INDICATOR PRESSURE INDICATOR

PRESSURE SWITCH DIIFF. PRESSURE INDICATOR FLOW INDICATION WINDOW

OIL LEVEL I NDICATOR

OIL LEVEL SWITCH

NON RETURN VALVE

SHUT OFF VALVE

ORIFICE

ADJUSTABLE ORIFICE

PRESSURE OIL

AUXILIARY OIL PUMP

EMERGENCY OIL PUMP

RETURN OIL

TG#3 LUBERICATION OIL CIRCUIT

GOVERNING SYSTEM

GOVRNING TYPE : HYDRODYNAMIC (TG#3 SR-III)GOVERN. MEDIA : OILGOVERNING OIL PRESS: 9.5-10 KG/CM2

(I/L / TRIP)GOVERNING OIL TEMP: 45-600C.SIMULATION TEST OF GOVERNING

SYSTEM.