A PRESENTATION ON 660MW TURBO-GENERATOR ,ITS AUXILIARIES AND ASSOCIATED SYSTEMS

ByAshvani Shukla

C&IBGR energy

STEAM TURBINE K-660-247

GENERAL INFORMATION

TG DECK IS VIS SUPPORTED AND HAS 26 CONCRETE COLUMNS (T1 – T26).

TG HALL IS CONSTITUTED OF 3 MAINS ROWS OF COLUMNS – A,B ,C ROW AND TWO BAYS – AB BAY AND BC BAY. THE WIDTH OF AB BAY IS 36m AND BC BAY IS 12m

CONDENSER TUBE BANKS (CW PATH) HAS AN INCLINATION OF 40.

THERE ARE TWO MAIN EOT CRANES FOR TG HALL.EACH EOT CRANE IS HAVING A CAPACITY OF 200t FOR MAIN HOIST AND 20t FOR AUXILIARY HOIST. 35.5m IS THE MAXIMUM VERTCAL DISTANCE A HOIST CAN TRAVEL.TANDEM OPERATION OF TWO EOT CRANES ARE ALLOWED.

RATED CONDITIONS LOAD : 660MW BEFORE HP STOP VALVE

STEAM PRESSURE : 247KSC STEAM TEMPERATURE : 5370C STEAM FLOW : 2023.75T/HR

AFTER HPC STEAM PRESSURE : 48KSC STEAM PRESSURE : 298.710C

BEFORE IP STOP VALVE STEAM PRESSURE : 43.2KSC STEAM TEMPERATURE : 5650C

STEAM FLOW TO REHEATER : 1681.12T/HR. DESIGN CONDENSER PRESSURE : 0.105KSC (abs.) COOLING WATER FLOW : 64000M3/HR FINAL FEED WATER TEMP. : 286.350C FREQUENCY RANGE: 47.5 – 51.5 Hz

STEAM TURBINE

Generator rated speed 3000 rpm Generator manufacturer - Electrosila No. of bleedings 8 Length of the turbine 36.362 m No. of stages

HPT 17 IPT 11x2 LPT-1 5x2 LPT-2 5x2 Total 59

STEAM TURBINE

Parameters Pr. Before HPC SV 247.0 Ksc Temp. before HPC SV 537.0 0C Steam flow 2023.75 TPH Pr. After HPC 48.0 Ksc Temp. after HPC 298.71 0C Pr. Before IP SV 43.2 Ksc Temp. before IP SV 565.0 0C Steam flow to reheat 1681.12

TPH Design Cond pr. 0.105 Ksc CW flow 64000 TPH Final FW Temp. 286.35 0C

STEAM TURBINE

Turbine Governing systemMode of Governing NozzleTypeE/HControl fluid Firequel-L make

Supresta-USANormal Operating Pr. 50 KscCapacity 600 lpmFluid pump motor rating 200 KWFilter material UltiporMesh size 25 µ

STEAM TURBINE Lube oil system

Lube oilTn-22C Russia Mobil DTE Oil light Teresso 32In accordance with ISO VG 32

Absolute viscosity 16.7 Centipoise Kinematic viscosity -32 Centistokes Specific gravity 0.89 Flash point 1800C Fire point 2400C Oil requirement per bearing

N1 200lpm N2 200lpm N3 450lpm N4 280lpm N5 350lpm N6 350lpm N7 350lpm N8 350lpm N9 600lpm N10 600lpm

STEAM TURBINE

Lube oil system Total oil system capacity 52000 lit Full volume of oil tank 58000 lit Material of tank SS Normal lube oil pressure 1.2 Ksc Oil temp at inlet of bearings

Normal 55 0C Maximum 59 0C

Piping SS Seal steam system

Source of gland sealing system During normal operation End glands of HPC & IPC During low load operation End glands of HPC & IPC + AS

Quantity of seal steam required 3.54 TPH Seal steam pressure at turbine glands 1.1-1.2 Ksc Seal steam temperature at turbine glands 160 0C

TURBINE SEAL STEAM

•TWO HEADERS OR COLLECTORS ARE THERE i.e. HOT COLLECTOR AND COLD COLLECTOR.•INITIAL SOURCE OF STEAM SUPPLY IS APRDS (UNIT HT,16KSC,310OC).•PRESSURE AND TEMPERATURE OF COLD HEADER OR COLLERTOR ARE 1.1TO1.15 KSC ABSOLUTE AND 140TO 180OC RESPECTIVELY.•PRESSURE AND TEMPERATURE OF HOT HEADER OR COLLERTOR ARE 1.1TO1.15 KSC ABSOLUTE AND RESPECTIVELY.

Turbine ProtectionOver speed trip110-112 %Low lube oi pressure 0.3 (g)KscLow vacuum trip 0.3 (abs)KscThrust bearing excessive wear trip

+1.2/-2.0 mmPressure relief diaphragm setting

1.2 (abs)Ksc

STEAM TURBINE

STEAM TURBINE

Materials of construction HP Outer casing 15Cr1Mo1V HP blade/carrier casings 15Cr1Mo1V IP Outer casing 15Cr1Mo1V LP inner casing Steel 3 LP Outer casing Steel 3 HP Shaft 25Cr1Mo1V IP Shaft 25Cr1Mo1V LP Shaft 26CrNi3Mo2V Moving blades

HPT first stage blades 18Cr11MoNiVNb (1-5) HPT other stages 15Cr11MoV (6-17) IPT first stage 18Cr11MoNiVNb (1-3) IPT other stages 15Cr11MoV (4-11) LPT last stage 13Cr11Ni2W2MoV LPT other stages 20Cr13 (1-2) LPT other stages 15Cr11MoV (3-4)

STEAM TURBINE

Fixed blades HPT first stage 18Cr11MoNiVNb (1-5) HPT other stages 15Cr11MoV (6-17) IPT first stage 18Cr11MoNiVNb IPT other stages 15Cr11MoV LPT first stage 12Cr13 (1-4) LPT Other stages 08 Cr13 (5)

Number of stages HPT

Impulse stages 1 Reaction stages 16

IPT Impulse stages 22 Reaction stages 0

LPT Impulse stages 20 Reaction stages 0

All rows of blades are integrally shrouded

STEAM TURBINE No. of HP Stop valves2 No. of HP Control valves 4 Type of control valve unit Block united No. of IP Stop valves 2 No. of IP Control valves 4 Type of control valves Separate No. of Journal bearings for turbine 8 No. of Journal bearings for Gen 4 No. of thrust cum journal bearing 1 Type of thrust bearing Tilting Type of journal bearing 6-Fixed & 2-Tilting pad Material of bearing shell Alloy steel Type of lining Babbit LPT diaphrams 4

STEAM TURBINE

Turbine model No K-660-247 Generator model No TBB-660-2T3 Strainers are installed in the steam chests of the stop valves In HPT, having passed the control stage and 8 stages which

generate left jet of steam (from generator towards front bearing) steam changes its direction 180° and flows between internal and external cylinders to 8 stages of right jet (towards generator)

In CRH lines, NRV has a bypass with electric valve and control valve to enable counter flow mode of HPT with the aim of warming up of cylinder and high pressure cross over pipes at turbine start up and cold condition

HPT has nozzle steam distribution system IPT has throttle steam distribution system On each upper half (cover) of low pressure cylinder four

membrane type relief valves are installed which are activated when the absolute pressure in exhaust nozzles rises up to 1.35 –1.4 Ksc absolute

TG SEAL STEAM SYSTEM

TO 2nd CHAMBER EXHAUSTTO BLED STEAM TO D/A

TO BLED STEAM TO LPH # 4

TO HOT SEAL STEAM HEADER

TO GSC

HPT

HPT SEAL STEAM CONNECTION

1ST CHAMBER 2ND CHAMBER

TO COLD SEAL STEAM HEADER

TO GSC

IPT

IPT SEAL STEAM CONNECTION

FROM COLD SEAL STEAM HEADER

TO GSC

LPT

LPT SEAL STEAM CONNECTION

IN HIGH PRESSURE DRAINAGE EXPANSION TANK A VALVES IN DRAINAGE COLLECTORS FROM EXTRACTION STEAM PIPES TO HPHs (10MAL20AA110, 10MAL20AA120, 10MAL20AA140) AND IN LOW PRESSURE DRAINAGE EXPANSION TANK VALVES IN DRAINAGE COLLECTORS FROM EXTRACTION STEAM PIPES TO LPHs(10MAL30AA110, 10MAL30AA120) CLOSE AUTOMATICALLY IF TURBINE LOAD INCREASES OVER 200MW AND AT THE SAME TIME ALL VALVES ARE OPEN IN THE CORRESPONDING STEAM EXTRACTION FROM THE TURBINE TO HPHs AND LPHs.

VALVES IN DRAINAGE PIPES OF HPBP AND LPBP (10MAL30AA107, 10MAL30AA108) CLOSE AUTOMATICALLY IF TURBINE LOAD INCREASES OVER 30MW.

CONTROL FLUID SYSTEM

FIRE RESISTANT SYNTHETIC HYDRAULIC FLUID FYRQUEL – L MANUFACTURED BY “SUPRESTA” IS USED AS OPERATING FLUID.ITS SELF IGNITION TEMPERATURE IS ABOUT 740OC.

OPERATING PRESSURE IS APPROXIMATELY 50KSC. OPERATING TEMPERATURE IS 45-55OC. CONTROL OIL SUPPLY UNIT CNSISTS OF A RESERVOIR (10MAX10BB001)OF CAPACITY 7.0m3 ,2NOS.OIL

COOLERS(10MAX10AC001,10MAX10AC002),DE-AERATOR,MESH FILTER,FINE FILTER(10MAX18AT001),DUPLEX FILTER(10MAX14AT001) AND 2 NOS. OF VERTICALLY MOUNTED CENTRIFUGAL PUMPS(10MAX11AP001,10MAX12AP001) DRIVEN BY AC MOTOR (1W+1S).EACH PUMP IS HAVING A CAPACITY OF 36m3/h AND DISCHARGE PRESSURE IS 50KSC.

CONTROL FLUID RESERVOIR IS SEPERATED BY TWO NUMBERS OF TANDEM MESHES OF CELL SIZE 0.25mm INTO TWO SECTIONS ,DIRTY AND CLEAN. DE- AERATOR IS INSTALLED INSIDE THE RESERVOIR INFRONT OF MESHES AND IT CONSISTS OF SLOPING PLATE ASSEMBLY.

CF FINE FILTER FOR REMOVING MECHANICAL IMPURITIES IS INSTALLED IN RESERVOIR. DURING NORMAL OPERATION CF IS SUPPLIED TO THE FINE FILTER THROUGH AN ORIFICE OF DIAMETER 4mm FROM UNSTABILIZED PRESSURE LINE VIA VALVE 10MAX18AA501 . AFTER THAT IT IS DISCHARGED IN THE DIRTY CHAMBER OF THE RESERVOIR. WHEN TURBINE IS STOPPED CF IS SUPPLIED TO THE FINE FILTER WITH THE HELP OF ANOTHER PUMP (CF TRANSFER PUMP,10MAX19AP001,CAPACITY 4m3/hr, AND DISCHARGE PRESSURE 25KSC) VIA VALVES 10MAX19AA503 AND10MAX19AA504 FOR FILTERING PURPOSE KEEPING MAIN PUMPS IN OFF CONDITION.

OIL PURIFICATION IS CONTINUOUS DUE TO FILTERING OF ITS PART VIA CONCURRENTLY MOUNTED WORKING FILTER CARTRIDGES INSTALLED INSIDE THE FINE FILTER HOUSING. FILTER CARTRIDGES DESIGN ALLOWS USAGE OF DIFFERENT FILTERING MATERIAL.

METAL SEMI-PINCEBECK MESH WITH FILTERING DEGREE OF 70 MICRONS TO FLUSH SYSTEM AFTER INSTALLATION OR MAINTENANCE.

FILTER BELTING FABRIC WITH FILTERING DEGREE 30 – 40 MICRONS FOR PRIMARY REFINING DURING TURBINE OPERATION.

FILTERING ELEMENTS MANUFACTURED BY ”PALL” WITH FILTERING DEGREE 12 MICRONS FOR CONTINUOUS OIL FILTERING DURING TURBINE OPERATION.

OCCURRENCE OF PRESSURE OF 0.1 TO 0.3KSC IN FILTER HOUSING WITHIN 1-3 HOURS SHOWS CORRECT ASSEMBLY OF FILTER AND ITS PROPER OPERATION. IT IS NECESSARY TO SWITCH OFF THE FINE FILTER AND REPLACE FILTERING ELEMENTS IF PRESSURE IN FILTER HOUSING RISES UPTO 2KSC.WHICH SHOWS CONTAMINATION OF FILTER FABRIC. INSIDE FILTER HOUSING THERE IS A RELIEF VALVE BYPASSING FLUID BESIDES FILTER CARTRIDGES WHEN THEY ARE CONTAMINATED AND PRESSURE RISES UPTO 5KSC. AN OIL LEVEL GAUGE WITH ALARM SYSTEM WHISKERS (10MAX10CL001,10MAX 10CL002) IS PROVIDED IN THE CLEAN SIDE OF THE RESERVOIR. NORMAL OPERATING LEVEL IS 700mm FROM THE UPPER COVER (30 GRADUATION OF L.G.) AND THE AMOUNT OF CF IS 2.5m3

MAXIMUM ALLOWALABLE UPPER LIMIT (WITH CF PUMPS IN STOPPED CONDITION) IS 150mm FROM THE UPPER COVER (85 GRADUATION OF L.G.) AND MINIMUM OPERATING LEVEL IS 800mm (20 GRADUATON OF L.G.) FROM THE UPPER COVER.

CF PUMP STOPS AUTOMATICALLY INCASE OF RESERVOIR OIL LEVEL LOW-LOW. FOR VISUAL OVSERVATION OF OIL LEVEL ,LEVELGLASSES HAVE BEEN PROVIDED IN THE BOTH SIDES (DIRTY

AS WELL AS CLEAN). DIFFERENTIAL PRESSURE SWITCH (10MAX10CP001) HAS BEEN PROVIDED TO WARN ABOUT INCREASE IN

PRESSURE DIFFERENCE IN SIDE THE MESH FILTER. ALLOWABLE DIFFERENCE IN MESHES DOESNOT EXCEED 150mm.

THE STANDBY CF PUMP STARTS WHEN THE RUNNING ONE TRIPS OR SYSTEM PRESSURE DROPS TO 36KSC. IT TAKES 2 MINS FOR THE SYSTEM TO GET PRESSURIZED. IF SYSTEM PRESSURE DROPS TO 20KSC (10MAX14CP001) AND STOP VALVES START CLOSING ,THE

OPEARTING PUMP WILL STOP AND NO SIGNAL WILL BE GENERATED TO START THE STAND BY PUMP (SENSING OIL LEAKAGE).

CF PUMP ALSO TRIPS ON FIRE PROTECTION. DUPLEX FULL PASSAGE FILTER WITH FILTERING DEGREE 20-25MICRONS IS INSTALLED IN GENERAL

PRESSURE COLLECTOR OF CONTROL SYSTEM.IF PRESSURE DIFFERENCE (10MAX14CP301,10MAX15CP301) ACROSS THE RUNNING FILTER REACHES 0.8KSC,THE STANDBY FILTER HAS TO BE TAKEN INTO SERVICE.

2 NOS.OF CF COOLERS (A&B) ARE INSTALLED IN THE CF SUPPLY LINE BEHIND THE DUPLEX FILTER. THESE COOLERS ARE DOUBLE PASS (BY WATER) SURFACE HEAT EXCHANGERS WITH TUBULAR DESIGN ,WATER STREAM FLOWS INSIDE THE TUBES AND CONSIST OF 148 TUBES OF SIZE 16X1500mm AND HEAT EXCHANGE AREA 25m2.CF FLOWS FROM TO DOWNARD.

COOLERS ARE DESIGNED FOR A MAXIMUM COOLING WATER PRESSURE OF 10 ± 0.5KSC AND CF PRESSURE OF 68.7 ± 0.5KSC.CF FLOW RATE TO EACH COOLER IS 50m3/hr AND PRESSURE DROP IS 0.2KSC. CW FLOW RATE TO EACH COOLER IS 80m3/hr AND PRESSURE DROP IS 0.194KSC.

FOR HYDRODYNAMIC FLUSHING OF PIPELINES DURING MAINTENANCE,THERE IS A BYPASS VALVE (10MAX14AA501)TO THE COOLERS WHICH SHOULD BE CLOSED AND SEALED DURING ROUTINE OPERATION.

IN THE INPUT AND OUTPUT TO THE COOLERS CF LINE IS PROVIDED WITH TRIPLE-PASS SWITCHING OVER VALVES WHICH PREVENT FALSE ACTIVATION OF BOTH COOLERS.

CF TEMPERATURE IS MAINTAINED (48-52OC)BY COOLING WATER FLOW VARIATION WITH THE HELP OF A FLOW CONTROL STATION CONSISTING OF A PNEUMATIC CONTROL VALVE (10PGM20AA001) AND A BYPASS MOTORIZED CONTROL VALVE(10PGM20AA002).IN CASE TEMPERATURE RISES TO 55OC (10MAX14CT001,10MAX14CT002),MOTORIZED BYPASS VALVE OPENS TO MAINTAIN THE CF TEMPERATURE. THE MAXIMUM LIMIT OF CW TEMPERATURE AT COOLER INLET IS 37OC.IF CW TEMPERATURE IS BELOW 36OC ONE COOLER CAN BE PUT OUT OF OPERATION.

CF SUPPLY TO CONTROL UNITS IS CARRIED OUT BY TWO PRESSURE COLLECTORS OF STABILIZED AND UNSTABILIZED PRESSURE.

CF IS SUPPLIED TO UNSTABILIZED PRESSURE COLLECTOR THROUGH AN ORIFICE OF SIZE 22mm. STOP AND CONTROL VALVE ACTUATORS ARE FED FROM THIS COLLECTOR.

INTO STABILIZED PRESSURE COLLECTOR WHICH FEEDS OIL TO ALL CONTROL DEVICES,CF IS SUPPLIED FROM THE SECTION BETWEEN PUMPS AND THE ORIFICE.

DUE TO THE ARRANGEMENT MENTIONED ABOVE ,THE PRESSURE VARIATION IN UNSTABILIZED PRESSURE COLLEECTOR CAUSED BY INCREASE IN CF CONSUMPTION WITH OPEN ACTUATORS AFFECTS IN A LESS DEGREE PRESSURE VARIATION IN STABILIZED PRESSURE COLLECTOR.

SPRING-WEIGHT ACCUMULATOR (10MAX20BB001) IS CONNECTED TO UNSTABILIZED PRESSURE COLLECTOR TO PREVENT DECREASE IN FORWARD PRESSURE IN CASE OF LOSS AC SUPPLY TO THE PUMPS FOR 5-7SECS OR DURING PUMP CHANGE-OVER.

THE SETTING OF FLUID PRESSURE LEVEL (45KSC) TO BE ENSURED BY THE ACCUMULATOR IS DETERMINED BY A WEIGHT WHICH IS CONCRETE FILLED IN THE SITE.

ONE NRV IS INSTALLED IN THE LINE CONNECTING THE ACCUMULATOR TO THE UNSTABILIZED PRESSURE COLLECTOR. ACCUMULATOR IS FILLED WITH THE CF THROUGH AN ORIFICE OF SIZE 5mm INSTALLED IN THE BYPASS LINE OF THE NRV.

TWO EXHAUST FANS (1W+1S) ,10MAX21AN001,10MAX21AN002 (CAPACITY OF 3200m3/hr AT A HEAD OF 5-20mm OF WATER COLUMN) ARE ALSO INSTALLED TO REMOVE CF VAPOUR FROM CF RESERVOIR AND SYSTEM.

THE EXHAUSTER SWITCHES ON AUTOMATICALLY WHEN CF PUMP STARTS AND SWITCHES OFF AUTOMATICALLY WITH 15mins TIME DELAY AFTER THE STOPPING OF CF PUMP AND CF SYSTEM PRESSURE DROPS BELOW 2.0KSC.

HYDRAULIC TEST OF PIPE LINES CARRIED OUT AT A PRESSURE OF 90KSC.HYDRAULIC TEST SHOULD BE CARRIED OUT AFTER ASSEMBLING,OVERHAUL AND INSPECTION.

CONTROL FLUID SYSTEM

CONTROL FLUID SYSTEM

Isolation valves on pump suction & discharge side Pump discharge pressure 50 Ksc Capacity 41 TPH Stabilized pressure header supply oil to servo motors of SV & CV Un stabilized pressure header with 22 mm orifice Accumulator in unstabilized pressure header CF tank capacity 6.9 m3

Duplex filter Control fluid transfer pump to empty the CF tank CF Temperature control by control station in the ECW line

COMPONENT OF GOVERNING SYSTEM

1. ELECTRO-HYDRAULIC CONVERTER – SUMMER – 8 NOS.2. SUMMER – 8NOS.3. ELECTRO-MECHANICAL CONVERTER – 8NOS.4. GOVERNING BLOCK

1. CONTROLGEAR(AE001) – 1NO.2. EMERGENCY GOVERNOR OR OVERSPEED GOVERNOR– 1NO.3. TRIP SOLENOID (AA213,AA214)-2NOS.4. TEST ELECTROMAGNETS(AA211,AA212) – 2NOS.5. ROTATIONAL SPEED DETECTOR -3 NOS.6. LIMITER OF PRESSURE (AA502) – 1NO.7. SPEED TRANSDUCER – 1NO.8. LEVER OF OVER SPEED GOVERNOR (AX201)– 1NO.9. PILOT VALVE FOR SUPPLY (AX202) – 1NO.

5. ACCUMULATOR – 1NO.6. OIL SUPPLY AND PURIFIER UNIT7. SERVOMOTOR OF HPSV – 2NOS.8. SERVOMOTOR OF HPCV – 4NOS.9. SERVOMOTOR OF IPSV – 2NOS.10. SERVOMOTOR OF IPCV – 4NOS.11. SERVOMOTOR OF CRH NRV – 2NOS.12. LOCKING PILOT VALVE (AA001,AA002,AB001,AB002)- 4NOS.13. EX.STOP VALVE SERVOMOTOR OR ESV (10LBQ10AA101)– 1NO.

DIFFERENT TYPES OF OIL1. HEAD PRESSURE LINE (STABILIZED,50KSC,10MAX15)

2. HEAD PRESSURE LINE ( NON-STABILIZED,50KSC,10MAX15)

3. LINE OF PROTECTION (50KSC,10MAX51)

4. LINE TO COCK THE OVERSPEED GOVERNOR SLIDE VALVE (50KSC)

5. CONTROL OIL LINE TO STOP VALVE SERVOMOTORS (50KSC,10MAX16)

6. CONTROL LNE TO SUMMATORS (35KSC,10MAX17)

TURBINE PROTRCTIONS

1. OUT OF TOLERANCE ROTOR OVERSPEED : ALARM AT 3300RPM AND TRIPPING AT 3360RPM

2. OUT OF TOLERANCE AXIAL DISPLACEMENT OF ROTOR: TOWARDS FRONT BEARING BY 0.6mm (-0.6mm) -ALARM. TOWARDS FRONT BEARING BY 1.2mm (-1.2mm) - TRIPPING. TOWARDS GENERATOR BY 1.4mm (+1.4mm)A- ALARM. TOWARDS GENERATOR BY 2.0mm (+2.0mm) - TRIPPING.

3. LUBRICATING OIL PRESSURE DROP: ALARM AT 0.70KSC AND TRIPPING AT 0.30KSC WITH 3SECS TIME DELAY.

4. PRESSURE RISE IN CONDENSER:ALARM AT 0.15KSC abs. AND TRIPPING AT 0.20KSC abs. PROTECTION IS INTRODUCED AUTOMETICALLY AT UNIT START-UP AFTER PRESSURE DROP IN CONDENSER LOWER THAN 0.15KSC abs. OR AT TURBINE SPEED INCREASE OVER 1500RPM. PROTECTION IS IN OPERATION UNTIL STOP VALVES ARE OPEN

5. INCREASE OF BEARING VIBRATION: ALARM SOUNDS AT INCREASE OF VERTICAL OR TRANSVERSE OR AXIAL COMPONENT OF VIBRATION ON ANY BEARING OF TG SET REACHES 4.5mm/s .TRIPPING OCCURS WITH 2 SECS TIME DELAY AT INCREASE OF VERTICAL OR TRANSVERSE COMPONENT OF VIBRATION OVER 11.2mm/s ON ANY TWO BEARINGS OF TG SET.

6. RISE IN STEAM TEMPERATURE AT HPT OUTLET:7. LIVE STEAM TEMPERATURE BEFORE TURBINE FALLS BELOW 470OC:8. LIVE STEAM TEMPERATURE BEFORE TURBINE RISES ABOVE 565OC:9. STEAM TEMPERATURE BEFORE IV FALLS BELOW 500OC:10. STEAM TEMPERATURE BEFORE IV RISES ABOVE 593OC:11. MOT LEVEL LOW-LOW:12. DRIP LEVEL HIGH-HIGH IN ANY HPH:13. ANY FAILURE IN TURBNE CONTROL SYSTEM ELECTRONICS:

14. GENETERATOR PROTECTION:15. FIRE PROTECTION OPERATED:16. EPB PRESED.

TURBINE LUBE OILSYSTEM

LUBRICATION OIL SYSTEM IS DESIGNED TO SUPPLY OIL TO TURBINE AND GENERATOR BEARINGS IN ALL TURBINE PLANT OPERATION MODES AND ALSO TO PROVIDE ROTOR JACKING OIL SYSTEM AND GENERATOR SEAL OIL SYSTEM WITH OIL.

LUBRICATION OIL IS ISO VG 32 TYPE WITH FOLLOWING PROPERTIES:

ABSOLUTE VISCOCITY : 16.7CENTIPOISE KINEMATIC VISCOSITY : 32CENTISTOKE SPECIFIC GRAVITY : 0.89 SPECIFIC HEAT : 0.459Kcal/Kg Deg.C FLASH POINT : 180OC FIRE POINT : 240OC DEGREE OF CLEANLINESS : 16/13 ISO 4406 PERMISSIBLE SUSPENDED PARTICLE SIZE : 25 MICRON WATER CONTENT : <10PPM

LUBE OILTANK IS MADE OF STAINLESS STEEL AND HAVING A CAPACITY OF 58m3 . PROVISION IS MADE FOR OIL TREATMENT INSIDE THE TANK BY PROVIDING TWO ROWS OF FLAT GRIDS WITH MESH DIMENSIONS 0.25mm LOCATED INSIDE THE TANK WHICH DIVIDES THE TANK INTO DIRTY AND CEAN COMPARTMENTS. THE AIR SEPARATOR CONSISTING OF TILTED METAL PLATES SET IS INSTALLED TO SEPARATE THE AIR DISSOLVED IN OIL.

THE OIL TANK HAS ATTACHMENTS FOR OIL DRAINING TO OIL TREATMENT PLANT FOR SLUDGE DRAIN AND TO EMERGENCY TANK INCASE OF FIRE.

NORMAL OPERATING LEVEL IS 600mm FROM TANK TOP COVER.ALARM IS AT 500mm AND TURBINE TRIP IS THERE AT 400mm.

4 NOS OF LUBE OIL PUMPS (SINGLE STAGE CENTRIFUGAL) ARE INSTALLED VERTICALLY ABOVE THE TANK .2 PUMPS (AUXILLIARY OIL PUMP) ARE ac MOTOR DRIVEN AND 2 PUMPS ARE dc (EMERGENCY OIL PUMP) MOTOR DRIVEN.

ONE PUMP WITH ac MOTOR IS CONTINUOUS RUNNING AND OTHER IS KEPT STANDBY. EACH ac PUMP IS HAVING A DISCHARGE CAPACITY OF 300m3/hr A DISCHARGE PRESSURE OF 4.3KSC. EOP WLL START IN CASE OF LOSS OF AC.EACH EOP IS HAVING A DISCHARGE CAPACITY OF 250m3/hr AND A

DISCHARGE PRESSURE OF 2 KSC.FOR HIGHIER RELIABILITY EOP DELIVERS OIL DIRECTLY TO THE BEARING BYPASSING COOLER AND THROTTLE VALVE.

TG LUBE OIL SUPPLY SYSTEM

TG LUBE OIL SYSTEM

TG LUBE OIL SYSTEM

Turbine oil is ISO VG 32 KV 20-23 CST at 500C Acidity Number < 0.05 mg KOH/r Viscosity index > 90

Bearings HPT Front N1 HPT Rear N2 IPT Front (TB) N3 IPT Rear N4 LPT-1 Front N5 LPT-1 Rear N6 LPT-2 Front N7 LPT-2 Rear N8 Generator Front N9 Generator Rear N10 Exciter Front N11 Exciter Rear N12

TG LUBE OIL SYSTEM

• DC Lube oil pump 1 No.

Equipment Capacity (m3/hr) Head (Ksc)

AC Lube oil pump 300 4.3DC Lube oil pump 250 2.0

• NRV & Isolation valve in each Lube oil pump discharge line

• Oil first goes to duplex filter instead of cooler

• Coolers Bypass line with isolating valve

• Hydraulic Pressure control valve maintains the pressure at the center shaft level at 1.2 Ksc

• PCV Bypass with throttling orifice which provides lubrication even at fully closed control valve

TG LUBE OIL SYSTEM

Oil is first delivered to bearing brasses through emergency tanks located on bearing cap

Emergency tanks capacity in m3

N1 0.43 N2 0.35 N3 0.75 N4 0.44 N5 0.44 N6 0.44 N7 0.44 N8 0.44 N9 0.5 N10 0.44 N11 0.1 N12 0.1

TG LUBE OIL SYSTEM

Lube oil temperature control by control station in the ECW inlet line to Lube oil coolers

View glasses in the oil return line from each bearing MOT Capacity 58 m3

Duplex filters fineness 25 µm Provision is made for oil cleaning by delivering a portion of

oil from the oil pressure pipe to the oil tank through the fine cleaning filter with fineness of 12-15 µm

Fresh oil is filled through the above filter only Oil recirculation pump to purify the oil Electrical oil heater of 152 KW capacity is provided for the

preliminary oil warming in the lubrication oil tank before turbine start up by running the oil recirculation pump

Oil draining to Emergency lube oil tank in case of emergency with MOV

TG LUBE OIL SYSTEM

Oil trap at the suction of the vapor extractor fans Oil trap drain to lubrication oil tank Jacking oil pumps suction also given from lube oil discharge header after

coolers & before control valve

TG JACKING OIL AND BARRING GEAR SYSTEM

Barring gear & Jacking oil system

Automatic barring gear engagement at the rotor stop and barring gear disengaging at the start-up

High pressure oil supply for bearing inserts oil jacking Barring speed 1.05 rpm Motorized barring gear Torque transfer from the barring gear motor to the

turbine shaft is carried out via three stage reducer and free wheel clutch

Reduction gear first stage shaft end mounts special handle for hand barring

Normal source for jacking oil pumps suction is from lube oil pumps discharge header after coolers

JOP discharge pressure: 120 Ksc

Barring Gear & Jacking oil system

Dozing devices at each bearing of the Turbine & Generator which contain strainer, NRV, orifice & isolation valve

Bearing jacking oil is supplied via separate lines for oil jacking of inserts of bearing no: 4-9

Stand-by bearing insert oil jacking pump is not provided as the system is designed to realize auxiliary functions at turbine start-up. If this pump does not start when it is required then also the turbine can be operated normally without any bearing damage and disturbance of turbine operation

Each bearing insert jacking oil line is equipped with orifice only

Both pumps cut in/cut out is 1500/1500 Barring gear cut in/cut out is 1500/1500

Barring Gear & Jacking oil system

Bearing Insert Oil Jacking Pump is started automatically, if the rotor neck displacement becomes more than 0.1 mm relative to the insert of any of bearings No. 4,…9 provided that the oil pressure to rotor jacking is higher than 45 kg/cm2 or the turbine rotor rotational speed is higher than 1500 rpm

Pump is stopped automatically, with time delay of 30 seconds, if the rotor neck displacement is less than 0.1 mm relative to the insert of bearings No. 4-9

GENERATOR SEAL OIL SYSTEM

GENERATOR SEAL OIL SYSTEM

Seal oil pumps suction from MOT No Hydrogen side seal oil pump Pumps re-circulation line directly to MOT Coolers bypass valve Magnetic filters 2 No. (1W+1SB) NRV in the seal oil line after filters DPR DPR bypass manual control valve

GENERATOR SEAL OIL SYSTEM

Damper tanks 2 No.: 1 for TE & 2 for EE, designed for oil supply to front and back generator shaft seals with drop, specified by the height of damper tank installation, and also to seal at short-time interruption in oil supply, at the moment of automatic transfer from working pump to standby and at generator runback with generator shaft seal pumps switched off

View glasses in return oil lines Float hydraulic seal functions as SOT Hydraulic seal overflows in to return oil header No SOST Provision of trap upstream of fans Fans suction is from return oil header

GENERATOR STATOR WATER COOLING SYSTEM

Water tank not on the generator Ejector to make vacuum over the water tank to prevent air

ingress Ejector cooling by auxiliary cooling water Air venting of Generator through Gas trap connected from

winding inlet and outlet headers Gas trap to determine hydrogen present which will be

extracted from trap cap to gas analyzer Coolers bypass valve Ion exchanger-1 contains anion & cat ion in H-OH form to

maintain conductivity Ion exchanger-2 contains anion & cat ion in Na-OH form to

maintain Ph if it decreases below 8 Ion exchanger-1 first will be put in to service for reducing

dissolved oxygen below 5.0 µs/cm and then it will be put out of service. Then Ion exchanger-2 will be put in to service to increase the Ph value. If conductivity increases above 12.5 µs/cm, Ion exchanger-2 to be stopped

STATOR WATER COOLING SYSTEM

STATOR WATER COOLING SYSTEM

Control valves at the inlet of individual Ion exchanger circuits

DM water flow through ion exchanger is 1.5 to 2.0 m No NAOH dozing system Ion exchangers separate bypass lines Mechanical filter at the inlet of Ion exchanger circuit Dissolved oxygen analyzer & Ph analyzer Winding inlet valve for flow adjustment Winding outlet valve for pressure adjustment Normal make up from DM make up line & emergency make

up line from CST Filter in the common make up line Control station in the common make up line

GENERATOR GAS SUPPLY SYSTEM

GENERATOR GAS SUPPLY SYSTEM

Two Hydrogen manifolds to connect 16 cylinders each Direct acting Pressure regulator installed on cylinder connecting line to Manifold header to reduce the Hydrogen pressure from 175 Ksc to 10 Ksc Total Pressure regulators 32 Safety valve on each manifold header which operates when the Hydrogen pressure in the manifold exceeds 10.5 Ksc MOV & NRV in each manifold header Three CO2 manifolds to connect 17 cylinders each Each manifold header contains MOV, NRV & Isolation valve MOV with manual bypass valve at the inlet of CO2 heater CO2 heater is steam heated Steam source is from auxiliary steam system Steam parameters: 15 Ksc & 210 0C MOV in the steam inlet line Steam exhaust will go to FWSV Dish flash tank Manifold header pressure is 175-20 Ksc Control station with Pressure regulator provided D/S of heater to maintain a pressure of 2.0-2.2 Ksc with manual bypass valve SV installed D/S of pressure regulator operates if the pr > 5.0 Ksc Capacity of one cylinder 50 lit

GENERATOR GAS SUPPLY SYSTEM

One Hydrogen manifold is in operation under normal operating conditions

If the pr decreases below < 10 Ksc, an alarm will come and operator connects the standby manifold and disconnects the first manifold

Two CO2 manifolds are in operation under normal operating conditions

If the pr decreases below < 20 Ksc, an alarm will come and operator connects the standby manifold and disconnects the first manifold

Provision is given for emergency removal of hydrogen from generator itself by providing a line with one manual isolating valve & 2 No. MOV

FLASH TANKS

DRAINS FROM THE TURBINE AND STEAM LINES ARE REMOVED TO TWO HP DRAIN FLASH TANKS - A (10MAL10BB001) AND B (10MAL20BB001) AND ONE LP DRAIN FLASH TANK (10MAL30BB001)

BOTH THE HP FLASH TANKS ARE HAVING A CAPACITY OF 2.6m3. LP DRAIN FLASH TANK IS ALSO HAVING A CAPACITY OF 2.6m3.

CONDENSER

Design LMZ Design CW Flow 64000 m3/hr Vacuum 77 mm Hg (abs) at 33 0C

89 mm Hg (abs) at 36 0C No. of passes 1 Total no. of tubes 22.225 (OD)x0.71 (t) -

2992022.225 (OD)x1.00 (t) - 2080

Tube material ASTM A-249 TP 304 Rated TTD 3.40C DT of CW 100C

CONDENSATE EXTRACTION PUMP

Design flow rate 238.75 Kg/s Discharge pressure 32.15 Ksc Shut off head 395 m Pump speed 1480 rpm Power input 972.3 KW No. of stages 6 Type of first stage impeller

double entry Depth 7.43 m

DE-AERATOR

Design Pressure 13 KscNo. of trays 896Spray valves 132Design temp for D/A 395 0CDesign temp for FST 250 0C

DRIP PUMP

Design flow rate 324.509 TPH Discharge pressure 43 ata Shut off head 306.7 m Pump speed 1486 rpm Power input 310.1 KW No. of stages 5 Type of first stage impeller centrifugal, single entry Depth 1090 mm

MDBFP

Pump flow 769.950TPH Suction temp 186.2 0C BP Suction pr. 14.05 ata BFP Suction pr. 21.01 ata BFP Discharge pr. 335.78 ata BFP Discharge temp.187.9 0C BP Discharge pr. 22.01 ata Shut off head 4830 m BFP Speed 6275 rpm BP Speed 1490 rpm Normal R/C flow 220 TPH HC Rated O/P Speed 6505 rpm Outer casing type barrel No. of stages 7 BFP warm up flow 15 TPH

TDBFP Pump flow 1283.14 TPH Suction temp 186.2 0C BP Suction pr. 14.10 ata BFP Suction pr. 28.24 ata BFP Discharge pr. 335.83 ata BFP Discharge temp. 187.8 0C BP Discharge pr. 29.06 ata Shut off head 4580 m BFP Speed 4678 rpm BP Speed 2098 rpm Normal R/C flow 365 TPH HC Rated O/P Speed 6505 rpm Outer casing typebarrel No. of stages 7 BFP warm up flow20 TPH

TDBFP GOVERNING SYSTEM

GOVERNING SYSTEM PARTS OF GOVERNING SYSTEM

Hydraulic Accumulator (HA) Remote switch (RS) Lubrication system pressure relay (LSPR) Trip Gear (TG) Stop valve (SV) Governor valve 1 (GV1) Governor valve 2 (GV2) Cut off pilot valve (COPV) Electro mechanical converter (EMC) Electro mechanical converter position transducer (ECPT) Electronic control part (ECP) Servo motor (S) Governor valves position transducer (GVPT)

TDBFP TURBINE Number of stages 9 Casing Split Steam admission Dual Steam pressure at inlet 20.82 ata Steam temperature at inlet 469 0C Turbine operating speed 4678 rpm Steam consumption 61.4 TPH Steam pressure at exhaust 0.128 ata Turning gear speed 15 rpm Type of governing system Electro-Hydraulic Over speed type trip Centrifugal + electrical JOP Not required Lube oil tank capacity 10.97 m3

Lube oil Same as main turbine

TDBFP CONDENSER

CW flow 3000 TPH Vacuum in the condenser 0.128 Ksc (abs) Total no. of tubes 3312 Tube OD and thickness 22.225x1.06 mm No. of water passes 2 Tube material ASTM A-249 TP321

TDBFP LUBE OIL SYSTEM

TDBFP EXTRACTION SYSTEM

TDBFP CONDENSATE SYSTEM

ACW SYSTEM

ACW SYSTEM

Suction header is from all the 4 CW inlet lines to condensers

MOV at Suction header from CW line MOV at SCS inlet MOV at PHE inlet & outlet Supply to

Ejector of Stator water cooling system TDBFP vacuum pumps (4 No.) Main turbine vacuum pumps (1 No. extra)

MOV at return header to CW line

TURBINE VACUUM SYSTEM

TURBINE HEATING FLANGES SYSTEM

AUXILIARY STEAM SYSTEM

CONDENSATE SUPPLY SYSTEM TO EXT NRVS

EXHAUST HOOD SPRAY

FEED WATER SYSTEM

TDBFP-A FEED WATER SYSTEM

MDBFP FEED WATER SYSTEM

LP DOZING & OXY TREATMENT SYSTEM

HP BYPASS SYSTEM

LP BYPASS SYSTEM