Gujarat State Electricity Corporation Ltd.

Thermal Power Station WTPS

TURBINE ROLLING AND GOVERING SYSTEM

• NITIN S PATEL

• DE

• OPERATION STAGE I

1NS PATEL

210 MW LMW TURBINE

The turbine is three cylinder, horizontal diaphragm type with nozzle governingand regenerative feed heating. The double flow LP turbine.

Boiler enters in two Emergency Stop Valves (ESVs) of high pressure turbine.From ESV, steam flows to four Control Valves (CVs) mounted on the casing.of High Pressure Turbine(HPT) at the central pedestal side

High pressure turbine comprises 12 stages , first stage being governingstage. The steam flow in HPT being in reverse direction . The blades in HPTare designed for anticlockwise rotation, when viewed in direction of steamflow

The intermediated pressure turbine has 11 stages . HP & IP rotors areconnected by rigid coupling and have a common bearing

After flowing through IPT, steam enters the middle part of low pressure turbinethrough two cross over pipes. In Low Pressure Turbine (LPT) 08 stages.

In order to heat the feed water in the regenerative cycle of the turbine ,condensate from the hot well of condenser is pumped by the CondensateExtraction Pump ( CE Pumps ) and supplied at the Deaerator throughEjectors, Gland Steam Cooler, four number L.P. Heaters and Gland Cooler.From Deaerator , the feed water is supplied to boiler by boiler feed pumpsthrough three number H.P. heaters. Extracted steam from various points ofthe turbine is utilized to heat the condensate in these heat exchangers.

TURBINE MAIN DATA:

Rated output of the Turbine : 210 MW.

Rated Speed : 3000 rpm.

Rated pressure of steam before ESV : 130 kg/cm2.

Rated live steam temperature : 535 °C

Rated live steam temperature at inlet of IV : 535 °C

Steam flow at valve wide open condition : 670 Tons/hr.

Rated CW flow through condenser : 27000 M 3 / hr.

Cold start( when casing temperature is less than 150°c)

Worm start (when casing temperature is between 150°c to 350°c)

Hot start (when casing temperature is more than 350°c)

Eccentricity of the rotor at barring gear speed is more than 0.07 mm

For a healthy turbine normally the vibrations are less than 40 microns

Turn the speeder gear hand wheel in anti-clockwise direction and CHECK THAT following events occurs:

Reading on the scale of Event

Speeder gear drum

4.6 mm Interceptor valves begin to open

5.5 mm Emergency stop valves begin to open

5.9 mm Interceptor valves fully open

6.65 mm Emergency stop valves fully open

9.6 mm Control valves begin to open

12.8 mm All control valves fully open.

Droop Calculation• FLY BALL GOVERNING SYSTEM• 120. F = 3000 RPM

p

• 50% 2900= 3.3 %• 33% 2850 = 5.0 % ( all M/C)• 25% 2800 = 6.66 %

• 0- 125 IP control valve All• 125-230 HP control valve 1 & 2• 230-270 HP control valve 3 • 270 to 300 HP control valve 4

5

% DroopNo Load Speed - Full Load Speed

Rated SpeedX 100=

Steam generation principle

Steam power plants operate on Rankine Cycle, DM water as working fluid.

Sensible heat is added in economizer +furnace

Steam generation takes place in water wall.

condenserCEP

LPH

BFP

HPH+Ecow/w

SHHPTIPT

RH

LPT

INTERLOCK & PROTECTION OF TURBINE :

Turbine lockout relay (TLR) will trip if,

Unit Lockout Relay trips (ULR).

Master Fuel Relay trips (MFT)

Oil level in damper tank is very low.

DM cooling Water flow to stator winding is less than 13 M³ / hr.

DM cooling water specific resistivity is less than 50K. ohm/cm.

Condenser vacuum is less than 540 mm of Hg.

Boiler drum level is very high / low.

H.P. turbine exhaust temperature is above 420 °C.

H.P. heater level is very high

Lub oil pressure is low 0.3 kg/cm² ).

Shaft axial shift is high ( +1.2 , – 1.7 mm.).

‘Low lub oil pr.’ & ‘High axial shift ‘ will also operate the following valves as under :

Open Vacuum Breaker.

Close steam to main ejectors.

Close steam to starting ejector.

Open air extraction valve of starting air ejector

The following condition will close the turbine ESVs and IVs :

Turbine Trip solenoid (TTS) operated.

Turbine over-speed trip operated ( 11- 12 %) .

Turbine over-speed trip addl. Protection operated ( 15% ).

Turbine relay oil pressure is less than 10 kg/cm2.

Turbine Manual Trip operated

COLD START UP OF TURBINE

The turbine is considered to be cold if the temperature of lower part of HPT casing is less than 150 0C.

ECCENTRICITY :

Eccentricity of the rotor in barring speed is more than 0.07 mm.

During steam rolling , if the readings as indicated on eccentricity meter exceed 0.20 mm ( 200 micron) , the turbine should be shut down and put on barring gear and cause of excessive indication be investigated.

BEARING VIBRATION

For healthy turbine, normally the vibrations are less than 40 microns

Critical speed of the shaft system are given below :

I II III IV V

1585 1881 2017 2489 4500

METAL TEMPERATURE:

While heating the casing of ESV, HPT & IPT and also while increasing speed and loading turbine, metal temperature should be raised gradually, avoiding sudden sharp rises. The rate of rise of metal temperature should not exceed the limits given below :

Temperature Rate

From 100 to 200 °C 20 °C per minute

From 200 to 300 °C 15 °C per 5 minute

From 300 to 400 °C 10 °C per 5 minute

From 400 to 500 °C 10 °C per 10 minute

From 500 to 535 °C 6 °C per 10 minute

The rate of heating of steam pipes should not exceed 25-30 0C per five minutes.

While heating the main steam and reheat steam pipes, the difference in temperatureof pipes should not exceed 150C. But when the turbine is on load , this differenceshould not be more than 100C. While raising the speed of set up to 3000 rpm thedifference of metal temperature between the left hand and right hand ESV shouldnot exceed 30 0 C.

The temperature difference between the upper and lower halves of HPT & IPT casingshould not exceed 50 0C near the regulation stage in case of HPT and near the zoneof steam admission in case of IPT.

Temperature difference between upper and lower flanges does not exceed 10 0C .

DIFFERENTIAL EXPANSION :

It is prohibited to raise the speed of turbine rotor or the load if the relative expansion (+) or contraction (-) of the rotor reaches the maximum permissible values given below :

For Rotor of HPT: (+) 4.0 mm or (-) 1.2 mm

For Rotor of IPT : (+) 3.0 mm or (-) 2.5 mm

For Rotor of LPT: (+) 4.5 mm or (-) 2.5 mm

(+) sign indicates that Rotor is longer than cylinder and vice versa for (-) sign.

In case of further increase in the differential expansion of rotor, stop further increase in live steam temperature and suspend further loading. If measures mentioned above are not sufficient, decrease the live steam temperature.

If HP rotor contracts quicker than the HP casing increase temperature of live steam and increase load or supply fresh steam to the front sealings of HPT and the entry of leak-off steam into heater no. 4.

If IP rotor expands quicker than the IP cylinder, stop the increase the temperature of steam after reheat or lower its temperature. If these measures are not sufficient, stop the increase in load too.

Bearing No.1

IP overall Expansion

Bearing No.2 Bearing No.3 Bearing No.4 Bearing No.5

HP overall Expansion

HPT DIFF EXPANSION

IPT DIFF EXPANSION

LPT DIFF EXPANSION

AXIAL SHIFT

LP overall Expansion

HPT DIFF -1.2 TO 4.0 MM

IPT DIFF – 2.5 TO 3.0 MM

LPT DIFF -2.5 TO 4. MM

AXIAL SHIFT +1.2 TO -1.7 MM

HPT DIFF – 0.8 MM give Rotor heating

IPT DIFF – 1.50 MM give Rotor heating

LPT DIFF - ve sign improve vacuum

If IP rotor contracts quicker than the IP casing , increase temperature of steam after reheaterand increase load or supply fresh steam to the front sealings of IPT and the entry of leak-off steam into heater no. 4

If LP rotor expands quicker than the LPT cylinder, worsen the vacuum and stop recirculation of condensate in the condenser.

If LP rotor contracts quicker than the LP casing, improve vacuum in the condenser.

During heating , speeding and loading of turbine, carefully watch the readings of theinstruments indicating :

Vibration of bearings.

Axial shift of rotors.

Differential expansion of all the three rotors.

Metal temperature of upper and lower halves of HPT flanges and studs and upper half of IPTflanges.

Oil temperature at the inlet and outlet of the bearings.

Babbit temperature of thrust bearings.

Pressure and temperature of steam at the control panel.

HP

T IPT

LPT

m m

LPH-4GC-II

AS-39 AS-40

40 Kg/cm²AS-1

AS-2

AS-3

AS-4

AS-5 AS-6

AUXI PRDS

GC-I

210MW LMZ TURBINE GLAND SEALING SYSTEM

07 kg/cm²

m

CONDENSOR

ES-12

Line up of turbine , MS, CRH and HRH lines :

MS Line, In-between drain, HP- bypass up/down steam drain valves.

HRH, CRH, LP –bypass drain valves to flash box.

PRDS, Gland seal steam supply line and ejector line drains.

HP and IP cylinder steam loop drains to flash box.

HPT and IPT cylinder drains.

Before drain of extraction NRV of extraction line to HP heater no. 7 & 5 to flash box. Before drain of extraction NRV of extraction to LP heater no. 2, 3 & 4 to flash box.

The following valves are to be kept closed :

Main steam stop valve (turbine side).

Main steam stop valve bypass isolating and regulating valves.

ESV, IV and control valves of HPT and IPT.

Before isolating valve of gland steam controller.

Before isolating steam valve of GC-1 ejector.

First isolating steam valve of starting and main steam ejectors.

After ensuring the closing and opening of all the above the following procedure are to be followed:

Open Main steam stop valve (Boiler end) equalizer both side when M.S. pressure is 10 kg/cm2. and temperature is around 200 0 C

after opening drains of CHR/HRH line, slowly charge the turbine auxiliary steam line by opening HP BYPASS controller (5-10%) and after sometime increase the pressure.

Check that operation and LP Bypass Full Open condition

Charge the steam supply header to turbine gland sealing and air ejector from PRDS for heating the lines. Check that line drains are operating.

Maintain MS Lines pressure at 14 kg/cm2 and temperature at 220 0C by raising MS pressure at 25 kg/cm2 and temperature at 280 0 C

Start starting Oil pump and maintain oil temperature at around 42 0 C

VACUUM PULLING :

Close Reheater vents of Boiler and atmospheric drain of HRH and CRH drains

Close vacuum breaker (CA-6).

Open first isolating valve to ejectors

Open steam valve to starting ejector and maintain steam pressure at 7.0 kg/cm2and open air off-take valves CA valves

When condenser vacuum reaches to 150 mm of Hg, charge the turbine gland steam and maintain the gland the gland steam header pressure at 0.10 to 0.15 kg/cm2.

Charge GC-1 steam side to maintain the GC-1 vacuum 60-80 mm hg by maintaining steam pressure 1.5 to 3.0 kg/cm2. Before charging the GC-1

When vacuum reaches to 400 mm Hg open MC-49 and MC-50 ( Condensate line to condenser steam throwing device (STD)

Check that the HPT evacuating valves CA-21, 22 and bypass valves across CRH line NRV’s (Ex-20, 21) are closed

Open LP bypass and HP bypass valves manually about 5% and allow the steam to flow in HP / LP bypass

HP bypass up stream pressure at 25 kg/cm2 and LP bypass upstream pressure at 0.5 kg/cm2 and Temperature of MS should be maintained around 300 0C

When MS line metal temperature before ESV have reached to 270 0C and super heater outlet temperature of steam is above 50 0C superheat , open bypass valves of MSV for heating the pipe line up to turbine

Open bypass valves across NRV’s in CRH (ES-20,21) and heat HP turbine up to a temperature of 150 0C. close CA-21 and CA-22

Open both the ESVs by 10-20 mm as per scale by operating the hand wheel and heat ESV body steam pipe up to HPT control valves to 150 °C. While opening ESVs, care should be taken so that the HPT control valves closed and steam Loop drains to flash box are open

Open both side IV about 10-15 mm as per scale by opening the hand wheel and heat the steam loops up to CVs up to 80 0C. Care should be taken so that during this

operation IPT CVs remain closed and the steam loop drains to flash box are open.

Check the steam pressure in HRH line, which should be less than 1 kg/cm2 before starting the heating of steam loops up to control valves (CVs) at IPT. If the pressure in the line is more than 1 kg/cm2, adjust and reduce the pressure by opening the LP bypass valve manually

The said CVs of IPT have been provided within built relief holes through which steam leaks into IPT which may cause disengagement of rotor from barring gear, if the pressure in hot reheat line exceeds 1 kg/cm2

The steam parameters at MSV by this time shall be 25 kg/cm2 and temperature of 300 0C

Close ESV and IV by operating the hand wheel, Close Speeder Gear to Zero position

When pressure in the RH line comes to condenser pressure, manually close the LP bypass valves. Thus bypass stations are manually closed before admitting steam in the turbine for rolling the set.

Metal temperature of pipes before MSV.

Metal temperature of ESV.

Metal temperature of steam admission lines of HPT & IPT.

Metal temperature of HR lines.

Metal temperature in the zone of regulating stage.

Metal temperature of IV.

Steam pressure and temperature before MSV,

Differential expansion of HP, IP & LP rotors. Axial shift.

HPT and IPT overall expansion

Before rolling turbine, ensure that condensate level, Deaerator level and drum level are within allowable limits.

Check that the eccentricity of the rotor is within limit (less than 70 microns).

Open CVs of HPT and IPT completely, with the help of speeder gear.

TURBINE IS READY FOR ROLLING:

Open the MSV bypass isolating valves of both sides.

Open the bypass regulating valve slowly thereby allowing steam to roll the turbine.

Being certain the turbine is in healthy condition, again raise the speed to 500 rpm by opening the regulating valve and soak the set for 10 minutes at this speed.

Smoothly raise the speed to 1000 rpm at the rate of about 50 rpm/ min by slow opening of the MSV bypass regulating valve. Soak the set for 20 minutes at this speed.

Raise the speed smoothly to 3000 rpm without pause. It is dangerous to run the set near the critical speeds and hence it is prohibited to hold the set in the critical speed zone

When turbine main oil pump develops pressure of 18 k/cm2 before NRV at about 2800 rpm, slowly close the discharge valve of Starting Oil Pump (SOP). See that the oil pressure in the governing system remains constant. Stop SOP and again open the discharge valve for operation during stopping of turbine

While raising the speed, control the temperature of oil entering the bearings. Maintain oil cooler outlet temp. around 45 0

During speeding up of the turbine increase the boiler firing rate so that the steam parameters before synchronization are as follows :

M.S. steam pressure : 25-30 k/cm2.

M.S. Temperature : 300 – 330 0C.

R.H Temperature : 300 – 330 0C.

Synchronize the machine and load the machine at 10-20 MW

After soaking the turbine for about 20 minutes at a load of 20 MW, close all the drain valves of steam lines, steam admission pipes, HR drain collector and IP drain collector

During heating of turbine under load, constantly monitor the differential expansion of HPT, IPT and LPT and the overall expansion of HPT & IPT

LOAD LIMIT PILOT VALVE

FOLLOW PILOT VALVE

SUMMATION PILOT VALVE

DIFFERENTIATOR

INTERMIDIATE PILOT

VALVE

EHT

FEED BACK PILOT VALVE

SERVOMOTOR PILOT VALVE

CONTROL VALVE SERVO

MOTOR

EGPV

ESV

IV

ISPUG

Control oil 20 atg

Primary sensitive oil 7.7 atg

Secondary senst. Oil 10.3 atg

Miscellaneous oil

Speeder Gear

Load limitor

210 MW LMZ GOVERNING SYSTEM BLOCK DIAGRAM

MOP

Protection oil

TTS

Turbine Cold Start up producer 210 MW LMZCooling water system:- બન્ને condenser ready હોવા જોઇએ. Line vent/ water box vent Open હોવા જોઇએ. બન્ને condenser ના Inlet/Outlet valve open રાખવા Water box ના Drain Open રાખવા પાણી full આવ્યા બાદ drain બધં કરવા. Interconnecting valve ખોલી Intake tunnel charge કરવી Proper venting થયા બાદ એક C.W pump ready કરી ચાલ ુકરવો CW system charge હોવાથી ACW Booster pump system ready કરી એક ACW

booster pump ચાલ ુકરવો, જો ACW system લેવી હોય તો પહલેા Tank level Normal કયાા બાદ system ready કરી એક pump ચાલ ુકરવો

BCW system Tank level Normal કયાા બાદ system ready કરી એક pump ચાલ ુકરવો

Seal Oil System:-1. MOT level normal હોવુ ંજોઈએ અને oil purifier service મા ંહોવુ ંજોઈએ 2. Turbine floor filter પહલેા ના isolating valve બધં, Damper tank ના valve બધં રાખવા 3. Seal oil system panel પર Auto/manual switch “Manual mode” પર રાખવી 4. D.C seal oil pump નો supply “ Off ” રાખવો 5. A.C seal oil pump suction valve open, R/C valve open તથા discharge valve closed રાખવા 6. A.C seal oil pump નો supply ready કરી pump ચાલ ુAMP 20 થી ૨૨ જેટલા રાખવા તથા pressure

12.0 થી 14.0 kg/cm² રાખવુ ંજો AMP વધારે હોય તો R/C valve ઓછો કરવો 7. Seal oil filter oil charge કરી Damper tank level Normal લઈ લેવુ ં8. સૌ પ્રથમ OPR દ્વારા thrust oil pressure 1.0 to 1.5 kg/cm² આપી return oil flow ચેક કરી લો 9. ત્યાર બાદ DPR ના bypass valve દ્વારા 0.6 to 0.9 kg/cm² આપી return oil flow ચેક કરી લો.10.H2 seal oil tank મા ંઓઇલ level maintain કરવા drain ખોલી 01 pot જેટલુ ંmaintain રાખવું11. Seal oil system normal હોય તો TMD/EMD ની સચૂના મજુબ Air pressure 01 kg/cm² જેટલુ ંરાખી

Damper tank/DPR/OPR “ Auto mode” પર મકુી float valve service મા ંમકૂવો 12.TMD ની સચૂના મજુબ air leak test માટે air pressure 3.5 kg/cm² જેટલુ ંલઈ લેવુ ં(24 hrs.) 13.D.C seal oil pump નો supply “ ON ” 14.Seal oil system panel પર Auto/manual switch “Auto mode” પર મકૂવી.

LUB Oil System:- MOT level normal હોવુ ંજોઈએ અને oil purifier service મા ંહોવુ ંજોઈએ Turbine box-up condition મા ંઅને TMD ના clearness મજુબ system service મા ં

લેવી Lub oil cooler ના oil side ના Inlet/Outlet valve open કરવા D.C Lub oil pump નો supply “ Off ” રાખવો A.C Lub oil pump suction valve open, તથા discharge valve closed રાખવો A.C Lub oil pump નો supply ready કરી pump ચાલ ુકરી ધીમેધીમે discharge valve

open કરવો Turbine ની બધી bearing મા ંreturn oil flow ચેક કરી D.C Lub oil pump નો supply “

ON ” કરવો Jacking oil pump supply ready કરી pump ચાલ ુકરવો Barring gear નો supply ready કયાા બાદ engage કરી ચાલ ુકરવુ ં Lub oil system normal થયા બાદ SOP ચાલ ુકરવો

Condensate system:-1. CST level normal હોવુ ંજોઈએ, Hot well pump ready and available 2. Hot well level normal maintain કરવુ ં3. GC-I, GC-II, ejector, LP heaters ના vent open કરવા 4. C.E pump suction valve open, Discharge valve closed હોવા જોઈએ 5. Mc-21 closed અને R/C open તથા MC-49/50 open રાખી C.E pump ચાલ ુકરવો 6. Proper venting થયા પછી LP heaters venting કરી Deareator level normal કરવુ ંAuxiliaries PRDS Adjacent unit inter connecting valve ખોલી steam charge કરવુ ંFeed water system ready કરી બધા BFP ના supply ready કરવા Boiler Lit-up કરતા પહલેા ચેક કરી લો Boiler MSV અને equalizing valve બધં હોવા જોઈએ Cold fill pump ચાલ ુકરી Boiler Drum level normal maintain કરવુ ં(-50 to -100)Drum, super heater અને Re-heater ના vent open હોવા જોઈએ (Eco ના vent બધં) Super heater Drain 1, 4, 8 અને master drain open હોવા જોઈએWater wall ના બધા drain બધં હોવા જોઈએBottom ash hopper sealing અને Filling કરેલુ ંહોવ ુ ંજોઈએBurner Tilting “0” position પર હોવુ ંજોઈએ

બને્ન APH ના Flue gas અને Air pass ready હોવા જોઈએ તથા બને્ન APH ના GB અને SB ના LO pump ચાલ ુહોવા જોઈએ અને બને્ન APH Electric drive motor પર ચાલ ુહોવા જોઈએStart-up vent open હોવા જોઈએ તથા Eco R/C valve open હોવા જોઈએSpray Zone totally isolated condition મા ંહોવા જોઈએLDO/FO pump/scanner air fan/Igniter air fan ચાલ ુહોવા જોઈએ

ID Fan System:-Instrument Air Pressure 06 kg/cm² જેટલુ ંmaintain રાખવુ ંIGV minimum, suction damper open, Discharge damper closed અને Electric supply ready હોવા જોઈએ હવે ID Fan ચાલ ુકરો. Discharge damper full open confirm કરી લો ત્યારબાદ IGV ધીમે ધીમે open કરી draught -5 mmwcl જેટલો maintain રાખવો.

FD Fan System:-L.O pump ચાલ ુહોવા જોઈએ IGV minimum, suction damper open, Discharge damper closed અને Electric supply ready હોવા જોઈએ હવે FD Fan ચાલ ુકરો. Discharge damper full open confirm કરી લો ત્યારબાદ IGV ધીમે ધીમે open કરી total airflow 250 to 280 mmwcl જેટલો maintain રાખવો. અને furnace DP 15 to 20 mmwc જેટલુ ંરાખવું

Purging માટે:-બધા જ Trip valve બધં હોવા જોઈએAirflow > 30% (280 mmwc)FO/LDO gun ના Hydro motor valve બધં હોવા જોઈએબધી Mills OFF અને Feeders OFF હોવા જોઈએ તથા બધા HAG બધં હોવા જોઈએકોઈપણ BOILER TRIP command ન હોવો જોઈએ (MFT સસવાય ) NO flame scanner બધા OFF હોવા જોઈએStart Purging command (6 mins) Purging completed (MFT Reset) બધા જ Trip valve open કરી Igniter નો command આપવો ત્રણ Igniter આવ્યા બાદ LDO/FO નુ ંselection LDO પર આપવુ ંત્યારબાદ AB Tire LDO gun નો command આપી ત્રણ gun Service મા ંરાખવી Flue gas temp 180 °C થી વધારે થયા બાદ CD tire મા ંFO gun ready કરી command આપવો.હવે CD tire મા ંત્રણ FO ની Service મા ંરાખી AB tire મા ંLDO gun cutoff કરવી હવે LDO/FO નુ ંselection FO પર આપવુ ંત્યારબાદ AB Tire મા ંબે FO gun service મા ંરાખવી હવે CD tire મા ંત્રણ FO dummy કરવી. Drum pressure 2.0 kg/cm² થયા બાદ vent બધં કરવા Drum level વધશે જેથી CBD/EBD દ્વારા maintain કરવુ ં

Turbine start-up procedure CW pump બીજો ચાલ ુકરવો. Deareator steam line charge કરવી. PCV-17 ના Isolating valve 02 turn જેટલા OPEN કરવા, PCV-14 ના Isolating valve 50% જેટલા OPEN કરવા.Steam ejector line અને Gland sealing line charge કરવી Drum pressure 5.0 kg/cm² થયા બાદ Super heater Drain 1, 4, 8 ના master drain 1T open રાખવો Starting Ejector service મા ંલઈ vacuum puling Start કરવુ ંજ્યારે vacuum 150 mm of hg થયા બાદ Gland sealing valve open કરી GC-1 Ejector charge કરવુ.ં ત્યારબાદ GS pressure 0.10 kg/cm² રાખવુ ંAS-40 IPT seal chamber OPEN કરવો હવે M.S line charge કરતા પહલેા ચેક કરી લો.( TR-3,TR-10 READING)TMSV તેના Bypass valve, ESV/IV, HP/LP Bypass valve, ES-20/21, CA-21/22 બધં હોવા જોઈએ M.S line atmosphere drain, In between drain અને HP/LP upstream line drain OPEN હોવા જોઈએDrum pressure 8.0 kg/cm² થયા બાદ BMSV ના Bypass ખોલી M.S pipe metal temperature 100 °C થયા પછી BMSV ધીમે ધીમે Full OPEN કરવા. M.S pressure 10 kg/cm² Temp 200°CM.S Pressure 20 kg/cm² Temperature 250 °C હવે એક BFP ચાલ ુકરો Boiler blow down 10-10 mints આપવુ ંDrum level maintain કરવુ ંTurbine side બધા જ Drain full open કરવા અને જે main steam side atmospheric drain છે તેને Flash tank મા ંdivert કરી લેવા હવે condenser vacuum વધારો ૩૦૦ થી 350 mm of hg

HP/IP Bypass system charge કરતા પહલેા:-HP pump ચાલ ુહોવો જોઈએ અથવા pump નુ ંpressure adequate હોવુ ંજોઇએStarting oil pump start કરી Lub oil temperature maintain 42°C CRH/HRH line drain, HP bypass down steam drain અને LP bypass up/down steam drain OPENપહલેા LP Bypass valve 20 % ખોલવો ત્યારબાદ HP Bypass 5% open કરી line haunting ન આવવુંજોઇએ એ પ્રમાણે valve ધીમે ધીમે વધારે open કરી pressure અને temperature maintain રાખવુંM.S Pressure 25 kg/cm² Temperature 280 to 300 °C

HRH Pressure 02 kg/cm² Temperature 280 °C હવે HRH pipe metal temperature નોંધી લો. HRH Pressure 05 kg/cm² જેટલુ ંmaintain કરવુ ંHP Turbine Back Heating:- (TR-27,TR,22,)HP exhaust temperature, Differential Expansions નોંધી લો. જો M.S pressure વધે તો AB tire મા ંએક FO gun dummy કરવી HP casing drain Full open, CA-21/22 Closed, After CRH NRV’s drain Closed.CRH NRV’s bypass valve ES-20/21 open કરી HP casing temp> 150°C અને HPOE> 07 mmHPT exhaust temperature maintain up to 200°C અને HPT differentials 1.0 to 2.0 mm વધશે LP exhaust temperature વધે તો MC-49/50 નો spray ચાલ ુહોવા જોઈએ

Loop Heating:- (TR-11)Open ESV/IV loop drains સાથે DW-13/14, IP casing drain, IV manually locked કરવા હવે HRH pressure reduce કરો 1.0 kg/cm² જેટલુ ંત્યારબાદ speeder Gear દ્વારાESV/IV 20% ખોલવો IV manually lock હોવાથી unlock કરી 20 % open કરવા Turbine MSV bypass valve open કરી Turbine Inlet pressure 05 to 10 kg/cm² જેટલુ ંરાખવુ ંHPT loop temperature >150°C અને IPT loop temperature > 100°C IPT casing temperature increased trend અને HPT exhaust temperature down થયા હોય તો LP bypass throttle કરી HRH pressure થોડુ ંવધારવુ ંHRH pressure વધવા થી Barring gear disengage થઈ જશે. HPT/IPT casing Top-bottom differential <50 °C Both ESV metal temperature raising trend and Left/Right differential < 30°CHPT Top/Bottom differential વધતો હોય તો HP casing drain throttle કરવા.

• Rolling પહલેા ચેક કરી લો:-• હવે condenser vacuum વધારો 5૦૦ થી 550 mm of hg

• Closed TMSV bypass valve, Closed CRH NRV’s bypass valve ES-20/21, Closed HP bypass valve

• HRH pressure “0” થયા પછી LP bypass બધં કરી CA-21/22 valve Open કરી બધં કરવા • જો M.S pressure વધે તો 1.4.8 master drain open કરવો અથવા FO gun dummy કરવી • હવે speeder gear દ્વારા ESV/IV અને Control valve FULL open કરવા • Turbine MSV bypass valve ખોલી Turbine speed 500 RPM (socking 10 mints) • AS-39 valve OPEN કરવો Lub oil temperature maintain 42°C • ત્યારબાદ Raise Turbine speed 1000 RPM ( 50 rpm/min ) 700 RPM generator ની

critical speed છે • 1000 RPM socking 30 to 45 mints રાખવુ ંHPT exhaust temp down આવવા થી

HPT differential - ve તરફ down આવશે હવે condenser vacuum વધારો 6૦૦ થી 650 mm of hg Full લઈ લો

3000 RPM speed લેતા પહલેા:-Drum level -50 to -100 જેટલુ ંરાખવુ ંID/FD Fan બીજી pair લઈ લેવી, ત્યારબાદ PA fan ચાલ ુકરી Base mill A ready કરવી heating મા ંરાખવીAB Tire મા ંચાર FO gun service મા ંરાખવી M.S pressure 25 kg/cm² Temp 300 to 330 °Cત્યારબાદ Raise Turbine speed 3000 RPM (Speeder gear વધારી up to 27 mm જેટલુ ં)Turbine speed 2600 RPM થયા બાદ TMSV Open કરવા (3000 RPM socking 10 mints) A. When Turbine(3000 RPM) slowly close the discharge valve of Starting Oil Pump (SOP). See that the

oil pressure in the governing system remains constant. Stop SOP and again open the discharge valve for operation during stopping of turbine

Synchronise કરતા પહલેા:-Field Breaker “ON “કરવુ ંExcitation “ON” કરવુ,ં DC supply switch “ON” કરવી Incoming / Running voltage સરખા match કરવા ત્યારબાદ synchro-scope “ON” કરી speeder gear દ્વારા speed maintain કરી machine Grid જોડે Synchronise કરો અને machine Load at 15 MWThe steam parameters MS pressure : 30 kg/cm²MS temperature : 330 °CHR temperature : 300 °C During heating of turbine under load, constantly monitor the differential expansion of HPT, IPT and LPT and the overall expansion of HPT & IPT.Turbine side ના બધા જ drain બધં કરવા, LPH ના extraction આપી દેવા,

HPC

metal

temp

MS

pressu

re

-ve

misma

tch

Extrac

t

match

+ ve

match

100 20 - 280 280

30 280 280

200 20 280 280 280

30 280 280 280

250 20 280 310 360

30 280 330 370

50 300 340 380

70 325 360 400

275 20 300 340 380

30 310 350 390

50 335 370 400

70 350 385 420

300 20 320 360 405

30 330 370 415

50 350 385 430

70 365 400 440

Temperature matching for turbine rolling (M.S Temp)