Turbine Manual

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TURBINE 
STAGE – II 
OPERATION MANUAL 
 
 
 
 
 
 
 
 
 
 
CONTENTS: 
CHAPTER – I : Technical Details Of Turbine Equipments
 
 
CHAPTER – II : General Description Of Turbine & Its 
Auxiliaries. 
 
CHAPTER –III : Constructional Details Of Turbine And Its
 Auxiliaries. 
CHAPTER – IV : Operation Of Turbine And Its Auxiliaries. 
 
CHAPTER – V : Modifications. 
 
CHAPTER –VI : List Of Drawings. 
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Chapter – I 
Technical Details Of Turbine & Its Auxiliaries. 
 
1.1 Turbine 2 
1.1.1 Construction 2 
1.1.2 Speed 3 
1.1.3 Bearing Temperature, Vibration, Moments, Weights 3 
1.1.4 Oil Supply, Oil Pumps 4 
1.2 Thermal Cycle Data 7 
1.3 Condenser Constructional Features 8 
1.4 Condenser Thermal Cycle Data (At 100 % MCR) 10 
1.5 LP Heaters 10 
1.6 HP Heaters 11 
1.7 Deaerator Design Data 12 
1.8 Deaerator Thermal Data 14 
1.9 Boiler Feed Pump Technical Data 15 
1.10 Circulating Water Pump - Technical Data: 19 
1.11 Auxiliary Oil Pump 22 
1.12 Jacking Oil Pump 23 
1.13 DC Emergency Oil Pump 23 
1.13.a Oil Vapour Exhaust Fan 24 
1.14 Turbine Lube Oil Coolers 24 
1.15 Lub Oil Filter 25 
1.16 Main Oil Tank 25 
1.17 Central Lub Oil System 26 
1.18 Main Oil Pump 27 
1.19 Condensate Extraction Pump – Technical Data 28 
1.20 Condensate Transfer Pump 29 
1.21 Auxiliary Cooling Water Pump 30 
1.22 Auxiliary Cooling Water Booster Pump 30 
1.23 Plate Type Heat Exchanger 31 
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1.24 Centrifuge 31 
1.25 Gland Steam Condenser 32 
1.26 Gland Steam Condenser Air Extracting Fans 33 
1.27 Main Ejectors 33 
1.28 Cooling Tower 34 
1.29 HP Bypass System 35 
1.30 Condensate Storage Tank 38 
Chapter – II 
General Description Of Turbine & Its Auxiliaries. 
 
2.1 Introduction Of Stage – II Turbine 
& Its Associated Systems 41 
2.2 Main Turbine 42 
2.3 Condenser 43 
2.3.1 Condenser On Load Tube Cleaning System 43 
2.4 Water Treatment Plant/ Stage-II 44 
2.5 Make-Up Water System 45 
2.6 Main Condensate System 46 
2.7 Circulating Water System 47 
2.7.1 Chlorination 48 
2.7.2 Dozing Of Organo Phosphate 49 
2.8 Cooling Towers 49 
2.9 Fire Protection System 50 
2.10 Deaerator 51 
2.11 Boiler Feed Pumps 52 
2.12 Ejectors 53 
2.13 Gland Sealing Steam System And Leak Off Steam 54 
2.14 Gland Steam Condenser 55 
2.15 HP And LP Bypass Systems 56 
2.16 Auxiliary Steam System 57 
2.17 Regenerative And FW Heating System 57 
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2.18 Auxiliary Cooling Water System 59 
2.19 Turbine Oil System 61 
2.20 Hydraulic Turning Gear And Hydraulic Lifting 62 
2.21 Turbine Stress Evaluator 63 
2.22 Turbo Supervisory System 64 
2.23 Turbine-Governing-System 64 
2.24 Centrifuge 65 
2.25 Air Conditioning 65 
2.26 Salient Thermal Cycle Data (At 100 % MCR) 66 
 
CHAPTER –III 
CONSTRUCTIONAL DETAILS OF TURBINE AND ITS AUXILIARIES 
 
3.1 Turbine 68 
3.1.a. Turbine oil system 79 
3.1.b. Turbine Stop and Control valves 88 
3.1.c. Turbine Protective Devices 95 
3.2 HP & LP B/P valves 103 
3.3 Electro Hydraulic Governing System 119 
3.4 Turbine Stress Evaluator 143 
3.5 Turbine Supervisory System 164 
3.6 Hydraulic Turning Gear 184 
3.7 Centrifuge 193 
3.8 Condenser 196 
3.9 Condensate Extraction Pump 204 
3.10 Ejectors, Gland Steam Condenser and Drain cooler 210 
3.11 Deaerator 219 
3.12 Boiler Feed Pump 225 
3.13 Circulating Water Pump 242 
3.14 Natural Draught Cooling Tower 247 
3.15 CTP, ACWP, ACWBP 255 
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3.16 Fire Protection System 260 
3.17 LP Heaters & HP Heaters 267 
CHAPTER –IV 
OPERATION OF TURBINE AND ITS AUXILIARIES 
4.1 Start-up of Turbine 
4.1.0. Preparation prior to rolling 270 
4.1.1. Cold 288 
4.1.2. Hot 291 
4.2 Shut-down procedures 294 
4.3 HP & LP B/P control system 
4.3.1. HP B/P system 296 
4.3.2. LP B/P system 315 
4.4 Turbine logics and protections 322 
4.5 Turbine governing system operation – MHG, EHC 327 
4.6 Operation of High capacity pumps 
4.6.1. Boiler Feed Pump 340 
4.6.2. Condensate Extraction Pump 345 
4.6.3. Circulating Water Pump 349 
4.7 Operation of Regenerative Feed Heaters 351 
4.8 Fire protection System 357 
4.9 Special operation procedures 
4.9.1. Boiler Hydro test 360 
4.9.2. Condenser Air Tightness Test 361 
4.9.3. Deaerator Safety Valve Floating 362 
4.9.4. Turbine Over speed Test 
Turbine Over Speed Oil Injection Test. 363 
Turbine Over Speed Test (Actual) 364 
4.9.5. Boiler passivation – Turbine readiness. 365 
4.9.6. Condenser vacuum Drop Test. 367 
4.9.7. System Make-Up Test. 367 
4.9.8. Turbine oil flushing. 368 
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4.9.9. Governing Characteristics. 369 
4.9.10. EHC Calibration. 370 
4.9.11. LP B/P Valve characteristics. 370 
4.9.12. Check List For Isolating And Draining CST-6. 371 
4.10 Emergencies. 372 
CHAPTER – V 
5.0 Modifications. 382 
CHAPTER –VI 
6.0 List Of Drawings. 390 
 
 
Turbine Stage – II 
Operation Manual 
Chapter – I 
 Technical details of turbine & its auxiliaries. 
1.1 TURBINE 
 TECHNICAL DATA FOR CONSTRUCTION AND SPEED : 
1.1.1 CONSTRUCTION: 
 Three – cylinder reheat condensing turbine 
 Single flow HP turbine with 25 reaction stages Type H 30 – 25 –2 
 Double flow IP turbine with 20 reaction Type M 30 – 20 
 stages per flow 
 
 Double flow LP turbine with 8 reaction Type N 30 – 2 * 5 
 stages per flow 
 
 2 Main stop and control valves Type EV 160 
 2 Reheat stop and control valves Type IV 320 
 2 Swing check valves in cold reheat line DN 450 
 2 Bypass stop and control valves DN 200 
 Extraction Swing Check valves: 
 Extraction 1 : no valve. 
 
 Extraction 2 : 1 swing check valve with auxiliary actuator , 
 1 swing check valve. 
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 Extraction 3 : 1 swing check valve with auxiliary actuator , 
 1 swing check valve. 
 
 Extraction 4 : 1 swing check valve with auxiliary actuator , 
 1 swing check valve. 
 
 Extraction 5 : 1 swing check valve with auxiliary actuator , 
 1 swing check valve. 
 
 Extraction 6 : no valve. 
 
 
1.1.2 SPEED: 
 
 Rated speed : 50.0 S-1 
 Speed limitation in load and 
 station auxiliary load operation 
 Max. speed , no time limitation : 51.5 S-1 
 Min. speed , no time limitation : 47.5 S-1 
 Permissible for a maximum of 2 hours 
 during the life of LP blading : speeds below 47.5 S-1 
 : speeds above 51.5 S-1 
 Speed exclusion range at operation 
 without load * : 11.67 S-1 to 47.5 S-1 
 Standard over speed trip setting : max. 55.5 S-1 
 This speed range should be passed through in one smooth 
operation to avoid endangering the blades due to resonance. 
 
1.1.3 BEARING TEMPERATURE, VIBRATION , MOMENTS, WEIGHTS: 
1.1.3.a BEARING TEMPERATURE: 
 
Alarm at 
Machine must be 
shutdown at 
 
Normal operating 
temperature 
below 75 °C 
90 120 °C 
Normal operating 
temperature 
above 75 °C 
100 120 °C8 
 
1.1.3.b VIBRATION: 
 Absolute 
bearing 
housing vibration 
Absolute Shaft 
vibration 
Nominal value for alarm 35 m 
30 m above 
normal level * 
Maximum value for 
alarm 
 120 m 
Limit value for tripping 45 m 200 m 
 
 
 
 
1.1.3.c MOMENTS OF INERTIA: 
 Rotor of HP cylinder 316.94 kg m2 
 Rotor of IP cylinder 1155.59 kg m2 
 Rotor of LP cylinder 9794.13 kg m2 
1.1.3.d WEIGHTS 
1. HP cylinder, assembled complete with steam inserts. 56.0 T 
2. IP cylinder, upper outer casing, complete 13.2 T 
 with out Steam inserts. 
 
3. IP cylinder, upper inner casing, complete with blading. 8.0 T 
4. LP cylinder, upper outer casing, complete. 17.7 T 
5. LP cylinder, upper outer shell of inner casing complete 15.5 T 
 With blading, carriers and diffuser. 
 
6. Rotor of HP cylinder, complete with blading. 7.5 T 
7. Rotor of IP cylinder, complete with blading. 15.8 T 
8. Rotor of LP cylinder, complete with blading. 48.0 T 
9. Main stop and control valve, complete without 7.0 T 
 Bend and pipe section. 
 
10. Reheat stop and control valve, complete without 11.5 T 
 Bend and pipe section. 
 
 Weights have been calculated with addition. 
 Slings chosen must provide sufficient security. 
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1.1.4 OIL SUPPLY, OIL PUMPS: 
 
1.1.4.a OIL SUPPLY 
Oil tank, rated capacity 20 / 32 m3 
Highest oil level from the top of tank (at rated speed) 800 mm 
Lowest oil level from the top of tank (at rated speed) 850 mm 
First oil filling (estimated) 30 m3 
Flushing oil quantity (estimated) 20 m3 
 
 
Oil cooler operation, number 1 
Oil cooler for reserve 1 
Cooling surface per cooler 280 m2 
Oil temp at cooler outlet, in operation min 38 °C 
 Normal 45 °C 
 Max 47 °C 
Oil temp at cooler outlet, when shutdown max. 75 °C 
Temperature rise of oil in bearings Normal 20 °C
 Max. 25 °C 
 
ESTIMATED OIL REQUIREMENTS OF BEARINGS 
Bearing 1 0.8 dm3 / s 
Bearing 2 9.1 dm3 / s 
Bearing 3 4.0 dm3 / s 
Bearing 4 3.5 dm3 / s 
Front generator bearing 3.5 dm3 / s 
Rear generator bearing 5.0 dm3 / s 
 
1 Duplex Oil filter for thrust bearing oil DN 100 
 
Filtration particle size 37 m 
Safety valve in Jacking Max 200 bar 
Oil system, setting. Min. 10 % 
 10 
 
Pressure limiting valve in Jacking 120 bar 
Oil system, setting 
 
Jacking oil pump, speeds when switching on and off. 
Jacking oil pump must be switched on at turbine speeds below 
approx. 8.5 S-1 to avoid damage to bearing. 
Jacking oil pump should be switched off at speeds above 
approx. 9.0 S-1 
 
 
 
1.1.4.b OIL PUMPS 
 
 MOP AOP DCEOP JOP 
Quantity 1 2 1 2 
Make BHEL KSB KSB Allweiler 
Type 
ETA 150 – 
50 VL 
ETA 100 – 33 
VL 
SDF 40 – R 54 
Capacity 
(rated) 
139 78.31 30 1.26 dm3 / s 
Discharge 
pressure 
(gauge) 
8.2 6.8 2.3 120 Bar 
Speed 50 24.66 24.3 49.16 S -1 
Drive Turbine E motor E motor E motor 
Make 
Enclosure IP 44 IP 44 IP 44 
Voltage 415 220 415 V 
Frequency 50 50 Hz 
Motor power 90 13.6 30 KW 
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540 rpm
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Rated 
current 
 168 57 A 
Starting 
current 
 1075 365 A 
 
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1.2.1 Salient Thermal Cycle Data (at 100 % MCR): 
 
S.No Subject Pressure Temp Flow 
 Ata deg C t/hr 
 
1. Saturated steam from boiler drum. 167 350 607 
2. Superheated steam after super heater. 152 540 657 
3. Superheated steam before HPSVs. 150 535 639.82 
4. Cold reheat steam to re-heater. 38.1 341.4 573 
5. Hot reheat steam to IP cylinder. 34.3 535 573 
6. Steam to LP cylinder. 7.17 318.8 504 
7. Exhaust steam to condenser. 0.1033 46.1 441 
8. Main condensate after CEPs. 19.8 46.3 529 
9. Main condensate after LPH-3. 8.46 120.3 529 
10. Feed water at Deaerator. 6.4 161 660 
11. Feed water after Boiler Feed Pumps. 188 164.3 660 
12. Feed water after HP Heater-6. 186.3 243 660 
13. Feed water after Economizer. 170.3 329 611 
 
1.2.2 Turbine efficiency: 
 
Turbine efficiency at 0.1033 ata back pressure 3 % make up 
including 2.5% non-recoverable auxiliary steam for 100 % MCR condition at 
cooling water inlet temperature 34  C and deminetalised water inlet 
temperature at 38  C = 42.8116 %. 
 
1.2.3. Protection from pitting & erosion: 
 
Special protection against erosion due to moisture impingement is 
provided by flame hardening of leading edges of the blades of last stage of 
the LP cylinder. 
 
 
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1.2.4. Tip velocity of LP cylinder last row blades: 
 
1. Tip diameter : 2.794m. 
2. Tip velocity :438.880 m/sec. 
1.2.5. Last stage annulus area: 
 
 Total : 2 * 5.0 Square meters. 
1.3 CONDENSER CONSTRUCTIONAL FEATURES : 
 Design Features: 
1. Number of condenser per unit : One 
2. Type : Rectangular down flow 
 type surface Condenser - 
 Divided water box with 
 two water passes in each 
 section 
3. Overall length of the condenser : 14000 mm 
4. Method of support for condenser : Floated over the 
 springs 
5. Number spring elements : 24 Nos. (in 2 rows) 
6. Loading data: 
a. Dry weight of condenser : 361 Tones 
b. Operating weight of Condenser : 555 Tones 
c. Weight transferred to LP cylinder : 190 Tones 
 from stability consideration 
 
d. Operating weight on springs : 365 Tones 
e. Hydraulic Test weight : 693 Tones 
f. Water to be filled in the 
 Hot well during spring adjustment : 4 Tones 
7. Hot well Storage capacity : 3 minutes of 
 pumping by CEP 
8. Number of end tube plates : 4 (2 on each side) 
9. Length between end tube plates : 10,000 mm 
 14 
10. C. W. Tubes: 
a. Length of the tube : 10,1 0 mm 
b. Tube OD and thickness : 25.4 x 0.7112 mm 
c. Tube material : Stainless steel (SS TP 316) 
d. Percentage tube thinning : 7.5 % (average) 
e. Number of tubes: 
 i) Condensing zone : 16148 nos. 
ii) Air cooling zone : 1240 nos. 
 TOTAL : 17658 
f. Total heat transfer : 14090 m2 
 surface area 
11. Number of support tube plates : 2 x 12 
12. Design Data: 
 Water side Steam side 
 i) Condenser pressure : 5.0 KSC full 
vacuum 
ii) Condenser temperature : 50 deg C 100 deg C 
13. Hydraulic test pressure 
i) Water box : 6.5 ksc 
ii) Steam space : By filling water up to 
 1m above the top row 
 of the tubes. 
14. Number of air take off pipes : Two 
 (with holes on their 
 bottom surface ) 
 
15. Circulating water Data: 
i) Design inlet temperature : 34 deg C. 
ii) Temperature rise in tubes : 8.6 deg C. 
iii) Flow quantity : 29000 m3 / hr 
 iv) Pressure drop across : 5.5 m W.C. 
 the tubes 
 15 
 
1.4 Condenser Thermal Cycle Data (at 100 % MCR): 
 
 Rate of steam flow from main turbine : 441.96 T/Hr. 
 Enthalpy of steam from turbine : 579.5 Kcal / kg. 
 Temperature of exhaust steam from turbine : 46.1 deg C 
 (* = 0.9335) 
 Condenser pressure : 0.1033 ata. 
 
1.5 LPHeaters 
1.5.1 LP HEATERS DESIGN FEATURES AND THERMAL DATA: 
 LP-DC LPH-1 LPH-2 LPH-3 
1. Type shell &tube shell &tube shell &tube shell &tube 
2. Tube side pressure 28 ksc 28 ksc 28 ksc 28 ksc 
3. Shell side pressure vacuum vacuum vacuum vacuum 
 & 3.5 ksc & 3.5 ksc & 3.5 ksc & 3.5ksc 
 
4. Tube side temperature 150 °C 150 °C 150°C 150 °C 
5. Shell side temperature 100 °C 100 °C 150 °C 210 °C 
6. Tube surface area 35 m2 317 m2 500 m2 426 m2 
7. No of water passes 1 2 2 2 
8. Tube outer diameter 16mm 16 mm 16 mm 16 mm 
9. Tube material TP 316 SS TP 304 SS TP 304 SS TP 304SS 
10. Tube thickness 0.889 mm 0.889 mm 0.889 mm 0.889mm 
11. Total number of tubes 501 
12. Tube length 1540 
 
 16 
 
1.5.2 LPH - Shell Side Safety Valve 
 LPH-1 LPH-2 LPH-3 
1. Type P 33 E 
2. Capacity 72.83 m3 /hr 72.83 m3 /hr 72.83 m3 /hr 
3. Set pressure 3.5 ksc 3.5 ksc 3.5 ksc 
4. Service temperature 400 °C 400 °C 400°C 
 
1.6 HP HEATERS 
1.6.1 HP HEATERS DESIGN FEATURES AND THERMAL DATA 
 
 HPH – 5 HPH – 6 
 
1. Type Surface- V type Surface- V type 
2. Tube side pressure 275 ksc 275 ksc 
3. Shell side pressure 19 ksc 48 ksc 
4. Tube side temperature 230 °C 281 °C 
5. Shell side temperature 210 °C 4581 °C 
6. Heat exchange surface area 703 m2 810 m2 
7. No of tube passes 2 2 
8. Design flow [tube side] 660.37 t/hr 660.37 t/hr 
9. Shell side flow: 
 i. Steam 33.77 t/hr 60.608 t/hr 
ii. Drain 60.86 t/hr ---- 
 Total 94.65 t/hr. 60.608 t/hr 
10. Enthalpy: 
a. Tube inlet side 168.6 kcal/kg 203.8 kcal/kg 
b. Tube Outlet side 203.82 kcal/kg 252 kcal/kg 
c. Shell inlet side 791.5 kcal/kg 736 kcal/kg 
d. Shell Outlet side 172.4 kcal/kg 209.6 kcal/kg 
11. Pressure drop [tube side – 0.66 ksc 0.72 ksc 
 without plugging] 
12. Terminal temp. Diff. 0 ° 0° 
 17 
13. Tube size 15.875 mm 15.875 mm 
14. No of tubes 952 952 
15. Wall thickness 13/14 BWG 13/14 BWG 
16. Shell material BQCS SA 516/ 60 BQCS SA 516/ 60 
17. Water box material CS CS 
18. Tube material SA 688 TP 304 SA 688 TP 304 
19. Tube sheet material CS CS 
1.6.2 HP Heater Safety Valve [Shell Side): 
 
 HPH –5 HPH – 6 
 
1. Make BHEL BHEL 
2. Material CS 216 WCB CS 216 WCB 
3. Capacity 55224.9 Nm3/hr air 65263.8 Nm3/hr air 
4. Set pressure 20 ksc [gauge] 48 ksc [gauge] 
5. Temperature 182 °C 222 °C 
 
1.7 DEAERATOR 
1.7.1 Deaerator Design Data: 
 
1. Type : Spray and Tray 
2 Layout : 
Deaerating Header : Horizontal (Top ). 
Deaerator storage tank : Horizontal (Bottom ). 
3. Code followed in the design : ASME Sec VIII Division I (1986). 
 and fabrication 
 
4. Design and Test parameters for header and storage tank : 
Design pressure : 7.4 Kg / cm2 and full vacuum. 
Design temperature : 250 o C. 
Test pressure : 11.1 Kg / cm2 (1.5 design pressure) 
Test temperature : Room temperature. 
 
 
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5. Weight of the deaerator : 
 Dry weight : 65 tones 
 Operating weight : 197 tones. 
 Flooded weight : 262 tones. 
6. Deaerator support: 
 Distance between the : 7500 mm. 
 centre and the roller support. 
 
Expansion rollers : provided at both ends. 
7. Elevation: 
 Deaerator floor : 27.0 M. 
 Deaerator centre line : 29.22 M. 
1.7.2 Deaerating Header: 
 
1. Dimensions : 
 Diameter : 2400 mm. 
 Length : 5800 mm. 
2. Spray nozzles: 
Material : Stainless steel. 
Number : 40 
3. Number of vertical stacks : 2. 
4. Number of trays in each stack : 5. 
5. Main condensate pipes : 2 Nos. (Left and Right ). 
 connecting header and 
 storage tank 
6. Steam pipe connecting : 1 No. ( at the Centre ). 
 header and storage tank 
 
1.7.3 Storage Tank: 
1. Capacity : 130 m3. 
2. Overall dimensions ( OD x Length ) mm : 3500 x 21400. 
 
 
 
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3. Safety valve : 
(i) Set pressure : 7 Kg / cm2 (g). 
(ii) Relieving Capacity : 40,000 Kg / hr . of 
 saturated steam. 
(iii) Number : 2. 
 
1.8.1 Deaerator Thermal Data: 
 
1. Mode of operation of deaerator : Variable Pressure 
2. Limit down to which oxygen : 0.005 cc / liter. 
 is removed 
 
3. Operating pressure : 6.6 ata (at 100% MCR). 
4. Minimum pegging pressure : 1.5 ata. 
5. Operating temperature : 161.9 o C (at 100% MCR) 
6. Normal source of steam for Deaeration : IVth Extraction steam of
 Turbine. 
 
1.8.2 Parameter at the point of extraction: 
 
I) Pressure : 7.2 ata. 
 Temperature : 319.4 o C. 
 Saturation temperature : 165.3 o C 
 Degree of superheat : 154 o C. 
ii) Enthalphy of steam : 740.5 Kcal / Kg. 
iii) Steam flow : 35.18 T/ hr. 
iv) Tapping point of extraction : IP cylinder outlet (from
 cross around pipes) 
 (after 45 stages). 
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1.8.3 Water Parameters: 
 Main condensate Feed water 
 (at inlet) (at outlet) 
1. Enthalpy (Kcal / Kg) : 121.3 162.8 
2. Temperature (o C) : 120.8 161.9 
3. Pressure : 8.5 ata 6.5 ata 
4. Flow : 530 T / hr 660 T / hr. 
 
1.8.4 Terminal Temperature DifferenceoC (TTD) : 
 
(Saturation Temperature of extracted steam – Out going feed water 
 temperature) = 3.9 deg C. 
1.8.5 IVth Extraction steam parameters at lower loads: 
 Pressure (ata) Flow (T / hr) 
1. 80 % load : 5.86 27.64 
2. 60 % load : 4.54 19.55 
 
1.9 Boiler Feed Pump Technical Data: 
 
1.9.1 Main Pump: 
 
1. Make : BHEL 
2. Discharge quantity : 420 m3/hr 
3. Speed : 5300 rpm 
4. Temperature : 162.5 C 
5. No of stages : 6 
6. Efficiency : 81 % 
7. Specific weight at suction : 905 kg /m3 
8. Minimum re-circulation flow : 100 m3/hr 
9. Power : 2840 kw 
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1.9.2 Thrust Bearing: 
1. Type : double thrust 
2. Size : 8159/2KP-2KP 
1.9.3 Coupling Between Hydro coupling & Pump, Motor 
 
 : flexible coupling 
1.9.4 Motor Of BFP: 
 
1. Type : squirrel cage induction 
 motor 
 
2. Speed : 1485 rpm 
3. Power : 4000 kw 
4. Ambient temperature : 50 C 
5. Weight : 13300 kg 
6. Drive end bearing : dia 160 Χ 140 
7. Non drive end bearing : dia 125 Χ 115 
1.9.5 Booster Pump: 
1. Type : single stage double 
 suction 
 
2. Flow quantity : 395 m3 /hr 
3. Speed : 1485 rpm 
4. Suction temperature : 162.5 c 
5. Power : 140 KW 
1.9.6 Thrust Bearing: 
1. Make : GLACIER metal Co. Ltd 
2. Size : 811/2KP-2KP 
3. Type : double thrust 
1.9.7 Mechanical Seal: 
1. Make : Durametallic 
2. Size : 4-250 PTO/type 503 
3. Type : sedol 
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1.9.8 Coupling Between Motor &Pump: 
1. Type : flexible coupling 
2. Make : TORSIFLEX Ltd 
3. Size : HB 4-140 
1.9.9 Hydro Coupling: 
1. Type : variable speed geared 
 Coupling2. Make : VOITH TURBO GMDH &CO, 
 GERMANY. 
 
3. Power : 2840 KW 
4. Gear ratio : 131/136 
5. Primary speed : 5404 rpm 
6. Full load slip : 1.8% 
7. Capacity of oil tank : 700 liters 
8. Oil type : servo torque- 10 
9. Gear type : herring bone 
1.9.10 Working Oil Pump: 
 
1. Type : centrifugal 
2. Quantity of working oil : 421 LPM 
 
1.9.11 Lub Oil Pump & Auxiliary Lub Oil Pump: 
 
1. Type : gear pump 
 
1.9.12 Motor Of Auxiliary Lub Oil Pump: 
 
1. Power : 5.5 kw 
2. Speed : 1445 rpm 
3. Volt : 415 volts 
4. Ampere : 11.2 amps 
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1.9.13 Working Oil Cooler: 
 
1. Type : L1 N1 09 16 04 
2. No of coolers : 2 
3. Capacity : 3 liters [oil], 47 liters [water] 
4. Cooling water flow : 41 m3/hr 
5. Cooling water inlet temperature : 38 C 
6. Cooling water outlet temperature : 48 C 
7. Oil flow : 25.26 m3/hr 
8. Oil inlet temperature : 95 C 
9. Oil side [shell side] operating pressure : 16 bar 
10. Water side [tube side] operating pr : 10 bar 
11. Oil outlet temperature : 55 C 
12. Shell side volume [oil] : 71 liters 
13. Water side volume [tube] : 51 liters 
14. Shell design temperature : 120 C 
15. Water design temperature : 50 C 
1.9.14 Lub Oil Cooler: 
 
1. Type : L1 N1 07 16 04 
2. No of coolers : 2 
3. Cooling water flow : 26.6 m3/hr 
4. Cooling water inlet temperature : 38 C 
5. Cooling water outlet temperature : 41 C 
6. Oil flow : 13.2 m3/hr 
7. Oil inlet temperature : 60 C 
8. Oil side [shell side] operating pressure : 16 bar 
9. Water side [tube side] operating pr : 10 bar 
10. Oil outlet temperature : 45 C 
11. Shell side volume [oil] : 47 liters 
12. Water side volume [tube] : 31 liters 
13. Shell design temperature : 120 C 
14. Water design temperature : 50 C 
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1.10 Circulating Water Pump - Technical Data: 
 
1. Type of the pump : 1400-50-MFD Vertical , Mixed 
 flow Diffuser , Non pull out type 
2. Number of stages : One 
3. Make : M/S Mather and Platt. 
4. Rated capacity : 16500 m3/hr. 
5. Pump efficiency at design : 86 % 
 Parameters 
6. Effective head at rated capacity : 27.5 m of liquid column. 
7. Power input to Motor at design : 1496.7 KW 
 capacity 
 
8. Water levels ( from the pump sump floor level ) 
 a) Minimum water level : 7.59 m 
 b) Maximum water level : 9.65 m 
 c) Normal water level : 8059 m 
d) Minimum submergence : 4.2 m if liquid column for 
 Required operation at any 
 point within the range of 
 operation. 
9. Pump bearings: 
a) Thrust bearing : Tilting pad type bearing ( oil 
 lubrication) 
b) Impeller shaft bearing : FINOSTOS – B 
c) Line and head shaft Bearing : FINOSTOS – B 
10. Coupling: 
 a) Line shaft coupling : Split Muff type rigid coupling 
b) Coupling between Motor : Flexible pin and Bush type 
 shaft and Pump shaft 
 coupling. 
11. Suction bell diameter : 1480 mm of I.D. 
 (To limit flow velocity at the 
 maximum flow within 2.977 
 m/second through column 
 pipe) 
12. Discharge pipe diameter : 1600 mm of I.D. 
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1.10.1 Guaranteed Performance Details Of Pump: 
 
1. Flow capacity : 16500 m3 / hr. 
2. Head developed at the rated : 27.5 m of water column. 
 capacity(excluding losses in the 
 pump assembly) 
3. Power input : 1496 KW. 
4. Shut off head : 40 m of liquid column. 
5. Rated speed ; 496 rpm. 
6. Range of operation : 30 % to 140 % of rated capacity. 
7. Noise level : 85 dB at 1.86 meter distance. 
8. Availability over the warranty period : 91 %. 
1.10.2 Motor Of Circulating Water Pump: 
1. Type of motor : CACA ( closed air circuit air 
 cooled ) SCR – IM – Three 
 phase induction motor. 
2. Service : Continuous. 
3. Rated continuous output at 40 C : 1760 KW. 
 ambient condition 
 
4. Rated speed : 496 rpm. 
5. Rated voltage and its variation : 6600 V + 10 % 
6. Rated frequency and its variation : 50 Hz + 5 %. 
7. Duty cycle / Designation : S1. 
8. Full load current : 193 A. 
9. No load current : 85 A ( indicative ). 
10. Rated power factor : 0.78. 
11. Efficiency at rated voltage and frequency 
 a) Full load : 96.3 %. 
 b) Three quarter load : 95.5 %. 
 c) Half load : 94.0 %. 
12. Method of starting : Direct on line starting. 
13. Starting current : 600 % of full load current. 
 
 
 
 26 
14. Starting time ( seconds ) at 100% at80% 
 voltage voltage 
 
a) with load(from cold and hot 4.2 12.6 
conditions ) 
b) without load ( from cold and 0.8 1.3 
hot conditions ) 
15. Make : M/s. Crompton greaves ltd. 
16. Insulation : Class „ F „ 
17. Space heaters : 4 Nos. 250 w , 240 V. 
1.10.3 Motor Bearings: 
 
Bearing details NDE bearing DE bearing 
 
a) Type Tilting pad type thrust bearig Cylindrical 
 + white metal lined journal roller bearing 
 bearing 
 
b) Make Crompton SKF 
c) Lubrication Oil bath Grease 
d) Lubricant Turbine oil grade ISO VG 56 Lithium base 
 Greese 
e) Recommended SERVO PRIME 57 (or ) SERVO GEM 2 
 equivalent 
f) initial quantity 150 litres 2100 gm 
g) Re lubrication 
 interval & One year 5 months 
 quantity 150 litres 250 gm. 
h) Cooling method Water cooled Naturally cooled 
i) Cooling water 20 to 30 litres per min 
 flow rate 
1.10.4 Lubrication chart: 
 
a) Pump – Tilting pad type thrust bearing 
 Manufacturer Recommended grade 
(i) M/s Indian oil corporation Servo system – 46 
(ii) M/s Hindustan petroleum ENCLO – 46 
(iii) M/s Bharat petroleum Hydral – 46 
 27 
b) Motor Top bearing – Tilting pad thrust type + journal bearing 
(i) Oil used Servo prime – 57 or equivalent 
(ii) Quantity 150 litres 
(iii) Interval of change One year 
c) Motor Bottom bearing: 
(i) Grease lubricant Servo Gem – 2 or equivalent 
(ii) Initial filling quantity 2500 gm. 
(iii) Replacement quantity 250 gm ( 5 months interval) 
1.10.5 Butterfly Valves In Circulating Water System: 
 
S.No Location Size Nos. Operation 
 
1. Cooling tower inlet lines 1600 mm 8 manual 
2. Condenser inlet lines 1600 mm 8 Electric motor driven 
3. Condenser outlet lines 1600 mm 8 Electric motor driven 
4. CWP discharge lines 1600 mm 14 Electric motor driven 
5. Make up water lines 1200 mm 4 manual 
6. Make up water line 
 for fore bay 900 mm 3 manual 
 900 mm 1 Electric motor driven 
7. Water supply lines to ADPH 300 mm 4 manual 
 900 mm 1 manual 
1.11 Auxiliary Oil Pump: 
 
1. Make : KSB Pumps LTD. 
2. Type : ETA 150-50 vl 
3. Discharge : 152.64 m3/hr 
4. Head : 84.2 m 
5. Speed : 1485 rpm 
6. Capacity : 2544 lpm 
7. Differential pressure : 7 bar 
 
 
 28 
1.11.1 Motor Of Auxiliary Oil Pump: 
 
1. Make : AEI Works, Calcutta 
2. Kw : 100 
3. Amps : 175 
4. Volts : 415 
5. Rpm : 1485 
1.12 Jacking Oil Pump: 
 
1. Make : ALLWEILER 
2. Type : SDF 40 –R54 
3. Capacity : 1.26 d m3/sec 
4. Discharge pressure : 120 bar 
5. Speed : 2949.6 rpm 
1.12.1 Motor Of Jacking Oil Pump:1. Make : SIEMENS 
2. Volts : 415 
3. Speed : 2945 rpm 
4. Full load current : 47.5 Amps 
 
1.13 DC EMERGENCY OIL PUMP: 
1. Make : KSB pumps Ltd 
2. Type : ETA 100-33 VL 
3. Capacity : 108.0 m3/hr 
4. Discharge pressure : 2.3 bar ( gauge ) 
5. Speed : 1425 rpm 
 
1.13.1 Motor Of DC Emergency Oil Pump: 
1. Make : Crompton Greaves 
2. Volts : 220-v dc 
3. KW : 15 
4. Speed : 1425 rpm 
 29 
1.13.a Oil Vapour Exhaust Fan: 
1. Make : SKS PVT Ltd 
2. Type : SHSH 
3. Capacity : 396 m3/hr 
4. Speed : 2840 rpm 
1.13.a.1 Motor Of Oil Vapour Exhaust Fan: 
1. Make : REMI Ltd, Mumbai 
2. Volts : 415 
3. Speed : 2840 rpm 
4. Full load current : 1.8 Amps 
5. KW : 0.75 
1.14 TURBINE LUBE OIL COOLERS : 
 No. of oil coolers per unit : Two. 
 No. of oil coolers in service : One. 
 No. of oil coolers in reserve : One. 
 Type : Vertical, single shell with 
 two water passes in tubes. 
1.14.a SHELL SIDE: 
Oil inlet temperature (max) - when shut down : 75 °C. 
Oil outlet temperature in operation 
(maximum) : 47 °C. 
Normal : 45 °C. 
Minimum : 38 °C. 
Type of baffles : Disc & dough nut. 
Cooling surface area : 280 m2. 
1.14.b TUBE SIDE: 
 
Circulating water flow : 360 m3/hr. 
Total no tubes : 1250. 
Tube side velocity : 1.04 m/sec. 
Tube size : dia 16 * 1 mm. 
Material of the tube : Admiralty brass. 
 30 
1.15 LUB OIL FILTER: 
1.15.A Old BOLL &KIRCH filter (In service in Units 6&7). 
Type No : 2-69-9-220-500-10NW-100 
Fab No : 233884/1B 
Filteration size : 37 microns 
1.15.B New BOLL & KIRCH filter (Installed in Unit 4& 5). 
 Drg No : Z100827 
 Type : BFD 180-580-80-08 GS-LUB 
 Flow rate : 33 cubic meter/hr 
 Filteration size : 37 microns 
 Operating pr : 8.5 bar 
 Allowable operating pr : 16 bar 
 Operating temperature : 45 deg C 
 Allowable operating temp : min. TS : -10 deg C, 
 max. TS : 80 deg C 
 Initial pr. drop : 0.2 bar at 48 cst (Clean 
 condition) 
1.16 MAIN OIL TANK : 
 
Location : Turbine intermediate 
floor level 3.5 mts. 
elevation. 
Number of tanks per unit : One. 
Number of filters mounted inside the tank: I) One no basket filter to 
filter the drain oil from 
the turbine oil system. 
 
 
 
 31 
Number of filters mounted outside the tank ii) 10 self cleaning filters to 
filter control oil before 
admission to governing 
system. 
iii) two nos of Y type 
strainers in the LP B/P 
rack. 
Total oil in the system with the tank level : to allow a retention time of 
 normal during normal 
 operation approx. 7 to 8 
 minutes from entry into the 
 tank to suction by the pumps. 
1.17 CENTRAL LUB OIL SYSTEM. 
1.17.a CLEAN OIL TANK: 
 
Location : „0‟ ML outside power
 house - Unit - 5. 
Total Nos. : One for 4 units. 
Capacity : 70 m3. 
1.17.b CLEAN OIL TRANSFER PUMP: 
 
Total Nos. : One for all the four 
 units of St-II. 
Make : PRAKASH INDUSTRIES. 
Output : 100 LPM. 
Pressure : 50 psi. 
1.17.c Clean oil transfer pump MOTOR 
 
Make : CROMPTON GREAVES. 
Type : 3 phase, 50 Hz 
 induction motor 
Voltage : 415. 
Amps. : 7.9 A. 
RPM : 1430. 
 32 
KW : 3.7. 
HP : 5.0 
1.17.d DIRTY OIL TANK: 
 
Location : „0‟ ML outside power 
 house.U5. 
Total Nos. : One for 4 units. 
Capacity : 70 m3. 
1.17.e DIRTY OIL TRANSFER PUMP: 
 
Total Nos. : One for each unit of St-II. 
Make : PRAKASH INDUSTRIES. 
Output : 100 LPM. 
Pressure : 50 psi. 
1.17.f Dirty oil transfer pump MOTOR: 
 
Make : CROMPTON GREAVES. 
Type : 3 phase, 50 Hz 
 induction motor 
Voltage : 415. 
Amps. : 7.9 A. 
RPM : 1430. 
KW : 3.7. 
HP : 5.0 
1.18 Main Oil Pump: 
 
1. Make : BHEL. 
2. Capacity : 139 dm3/hr. 
3. Discharge pressure : 8.2 [gauge]. 
4. Speed : 3000 rpm. 
5. Drive : Turbine . 
 
 
 
 
 
 
 33 
1.19 Condensate Extraction Pump: Technical Data 
 
 Number of Pumps for one Unit : Two 
 Number of Pumps in Service : One 
 Number of Pumps in reserve : One 
 Type of the pump : Vertical Multistage 
 Centrifugal Canister Type 
 Specification : En 6J 40D 
 Number of Stages : 6 
 Type of Stage (i) First Stage : Double Suction Type 
 (ii) Other Stages : End Suction Type 
 Differential head : 225 m of Wcl. 
 Capacity : 678m3/Hr. 
 Rated Speed : 1482 rpm 
 Power absorbed : 507 KW 
 Efficiency : 81% 
 Suction bore diameter : 400mm 
 Discharge bore diameter : 300mm 
1.19.a Motor Of Condensate Extraction Pump: 
 
Voltage : 6600 V 
Rated Speed : 1482 rpm 
Rated Power : 600 KW 
1.19.b Thermal Cycle Data (AT 100% MCR) 
 
The temperature of main condensate : 46.1C 
in the hot well of condenser 
 
The absolute pressure in the Condenser : 0.1033 ata 
Flow of Main Condensate towards 
Deaerator : 529.2 T/Hr. 
The temperature of main condensate 
After gland steam condenser : 48.0 C 
After drain cooler : 48.7 C 
After LP Heater (1) : 56.4 C 
 34 
 After LP Heater (2) : 89.9 C 
After LP Heater (3) : 120.3 C 
The main condensate pressure at : 19.84 Kg/Cm2 (a) 
CEP discharge 
1.20 Condensate Transfer Pump A : 
a) Motor: 
1. Type : induction motor 
2. Make : G.E.C 
3. Power : 110 KW 
4. Supply : 415 v, 3 phase 
5. Speed : 2980 rpm 
6. Ampere : 190 amps 
b) Pump: 
1. Make : BEACON WEIR Ltd, Madras 
2. Capacity : 180 m3/hr 
3. Head : 140 m 
4. Speed : 2930 rpm 
1.20.a Condensate Transfer Pumps B & C: 
a) Motor: 
1. Type : induction motor. 
2. Make : ABB or Kirloskar. 
3. Power : 47 KW. 
4. Supply : 415 v, 3 phase. 
5. Speed : 1475 rpm. 
6. Ampere : 110 amps. 
b) Pump: 
1. Make : Kirloskar. 
2. Capacity : 200 m3/hr. 
3. Head : 55 m. 
4. Speed : 1470 rpm. 
 35 
 
1.21 Auxiliary Cooling Water Pump: 
a) Motor: 
1. Type : induction motor 
2. Ambient temperature : 50 C 
3. Speed : 985 rpm 
4. Power : 100 kw 
5. Supply : 415 v ,3 phase 
6. Ampere : 180 amps 
7. Synchronous speed : 1000 rpm 
b) Pump: 
1. Type : centrifugal 
2. Make : BEACON WEIR Ltd, 
Madras 
3. Total head : 20 m 
4. Capacity : 347.2 LPS 
5. Power : 79.17 KW 
6. Efficiency : 86% 
7. Speed : 985 rpm 
1.22 Auxiliary Cooling Water Booster Pump: 
a) Motor: 
1. Make : G.E.C 
2. Power : 22 kw 
3. Supply : 415 v,3 phase 
4. Ampere : 41 amps 
5. Speed : 1470 rpm 
b) Pump: 
1. Type : centrifugal 
2. Make : BEACON WEIR Ltd, 
 Madras 
3. Total head : 20 m 
4. Capacity : 69.4 lps 
 36 
5. Power : 16 kw 
6. Efficiency : 84.7% 
7. Speed : 1470 rpm 
 
1.23 Plate Type Heat Exchanger: 
 
1. Make : ALFA LAVEL 
2. Type : AX30 BFM 
3. Maximum working temperature : 50 C 
4.Maximum working pressure : 6 bar 
5. No of plates : 130 – 140. 
6. No. of heat exchangers per unit : Three. 
1.24 Centrifuge: 
 
1. Make : ALFA Level 
2. Type : MAB 206 
3. Capacity : 6000 liters/hr 
4. Speed : 8425 rpm 
1.24.a Motor Of Centrifuge: 
1. Make : Bharat Bijlee 
2. Volts : 415 
3. Speed : 1440 rpm 
4. Full load current : 14.7Amps 
5. KW : 7.5 
1.24.b Centrifuge Booster Pump Motor: 
 
1. Make : Bharat Bijlee 
2. Type : IMI 31324 
3. Volts : 415 
4. Speed : 1450 rpm 
5. Full load current : 8.15 Amps 
6. KW : 3.7 
 
 37 
1.24.c Centrifuge Heaters 
 
1. Type : Indirect type heaters .
 immersed in water. 
2. No of Heaters : 3 
3. Total power : 72 Kw 
i. Heater I : 36 Kw 
ii. Heater II : 18 Kw 
iii. Heater III : 18 Kw 
4. Voltage : 415 V 
5. Phase : 3 
6. Cap. Of water tank : 450 liters 
7. Area Heat Transfer : 11 Sq. meters 
1.25 GLAND STEAM CONDENSER: 
 
Number per unit : One. 
Type : Horizontal, Single Pass 
 Surface Condenser. 
Hydraulic test pressure 
 i) Shell side : 36.0 Kg/cm2 
Design pressure/Temperature. 
 i) Shell side : 24.0 Kg/cm2/150°C 
 ii) Tube side : 24.0 Kg/cm2/150°C. 
No. of tubes : . 
Surface area : 20 m2. 
Drain condensate temperature leaving the : 99.9 °C. 
gland steam condenser at full load. 
Main condensate flow through gland : 529.276 T/hr.. 
steam condenser at full load. 
Main condensate temperature at Gland : 48 °C. 
Steam Condenser outlet at full load. 
Weight ; 808 kg. 
 
 38 
1.26 GLAND STEAM CONDENSER AIR EXTRACTING FANS: 
 
No. of fans per unit : Two. 
No. of fans in service : One. 
No. of fans is reserve : One. 
Manufactured by : SK system pvt limited. 
Type : Single stage, 
 Centrifugal radial fan. 
Static pressure : 310 mm of WG. 
Rate of flow : 1080 m3/hr. 
Speed : 2840 rpm. 
Fan input power : 3.0 HP. 
1.26.a MOTOR: 
 
Manufactured by : 
Voltage : 240 / 415. 
Amps. : 26/15 
KW : 7.5 
Speed : 2900 rpm. 
1.27 MAIN EJECTORS: 
 
No. of ejectors per unit : Two. 
No. of ejectors in service : One. 
No. of ejectors in reserve : One. 
Manufactured by : M/S BHEL Ltd. 
Type : Steam Ejector. 
Weight : 3000 kg. 
No. of stages : Three. 
Source of steam supply for ejectors : Aux steam from AST Hdr 
 at 6.5 ksc & 210 °C. 
Tube side test pressure : 24 ksc. 
Tube side test pressure : 36 ksc. 
Shell side test pressure : 2.5 ksc. 
 39 
Steam consumption (about) : Kg/hr. 
Main condensate flow : T/hr. 
through (Min./Max.) ejectors. 
Temperature of main condensate : ° C at inlet 
min./max. 
Main Condensate Flow/Through : 529.276 T/HR. 
Ejectors at 100% mcr. 
Main Condensate Inlet Temperature To Ejectors : 46.3 / 47.6 °C. 
Steam Consumption For Ejector (Both Stages) : Kg/HR. 
1.28 COOLING TOWER 
1.28.1 Operation Data: 
 
a. Design capacity of the tower : 30,000 m3/hr 
b. Design cold water temperature : 33.19 deg C 
c. Hot water inlet temperature : 42.73 deg C 
d. Design approach : 5.19 deg C 
e. Design atm. Wet bulb temperature : 28 deg C 
f. Wind velocity for performance : calm 
g. Design atm relative humidity : 50 % 
h. Pumping head at the entry of the tower : 12 M of water column 
1.28.2 Design Parameters: 
 
1. Sprinkling density (L) or cooling 
 Water flow in Kg/Hr M2 fill area : 5364 Kg/M2/Hr. 
2. Dry air flow (G) Kg/M2/Hr. : 2823.7 kg/m3/hr 
3. Effective fill volume (inclusive of air gap) : 31,700 m3. 
4. Ratio of water to air weight (L/G) : 1.8998. 
5. Temperature of leaving air 
(i) Dry bulb temperature : 40.04 deg C. 
(ii) Wet bulb temperature : 39.91 deg C. 
6. Total dry air flow per tower : 17,370 X 103 kg/hr. 
7. Inlet air enthalpy above 0 deg C : 21.18608 kcal/kg. 
8. Total wet air flow per tower : 17,719 X 103 kg/hr. 
 40 
9. Sensible heat gain by dry air thro‟ tower : 0.73264 kcal/kg 
10. Latent heat gain by dry air : 17.3686 kcal/kg 
11. Exit air enthalpy above 0 C : 39.28732 kcal/kg 
12. Total heat exchanged per Kg of inlet air : 18.10124 kcal/kg 
13. Total heat exchanged per hour : 314.82 X 106 kcal 
14. Evaporation loss (maximum) : 519.36 m3/hr 
15. Drift loss (maximum) : 9.9 m3/hr 
16. Wetted packing surface per sq.m of tower area : 19 m2/m2 (laths only) 
1.29 HP BYPASS SYSTEM 
 
1.29.1 HP B/P Oil Supply Unit: 
 
1. Type : OV 32 B-30-201 
2. Oil used : Servoconval 46 
3. No of OSUs per unit : 2 
4. Operating oil pressure : 100 bar 
5. Set pressure for opening of 
Safety relief valve : 180 bar 
6. Volume of oil tank : 70 litres 
1.29.2 Pump Of Oil Supply Unit: 
 
1. Make : BOSCH 
2. Type : Axial piston type 
3. Speed : 1500 rpm 
4. KW : 7.5 
5. Discharge rate : 24 litres /min 
6. Discharge pressure : 170 ata 
1.29.3 Motor Of Oil Supply Unit: 
 
1. Make : BBC Brown Beweri 
2. Type : Intermittent duty 
3. Speed : 1440 rpm 
4. KW : 7.5 
5. Volt : 415 
 41 
1.29.4 Filters Of Oil Supply Unit: 
1.29.4.A. Suction filter: 
1. Filtration rating : 100 micron 
2. Filter material : Phosphor bronze wire 
 mesh 
3. Max press drop rating : 2 Mpa 
1.29.4.B. Pressure filter [coarse]: 
 
1. Filtration rating : 10 micron 
2. Filter material : Super micronic type .
 852.127 
1.29.4.C. Pressure filter [fine]: 
 
1. Filtration rating : 3 micron 
2. Maximum operating pressure : 350 bar 
3. Allowable differential press [max] : 7 bar 
1.29.5 Steam Valves BP1 & BP2: 
 
1. Design pressure : 170/50 ata 
2. Design temperature : 540/ 485 ºC 
3. Body material : 10CV Mo 910 
4. Nozzle material : 10CV Mo 910 
5. Maximum flow : 236.05 T/hr 
6. Seat diameter : 100 mm 
7. Maximum valve stroke : 46 mm 
1.29.6 Actuator Of BP1 & BP2: 
 
1. Type : hydraulic 
2. Design : ASM 210-10-KSK 
3. Hydraulic system pressure : 100 bar 
1.29.7 Spray Control Valves BPE1 & BPE2: 
 
1. Valve design : E32 S 
2. Maximum valve stroke : 40 mm 
3. Design pressure : 280 ata 
 42 
4. Design temperature : 175 °C 
5. Body material : 15 Mo 3 
6. Nozzle material : 15 Mo 3 
7. Maximum flow : 32.22 T/hr 
8. Seat diameter : 30mm 
1.29.8 Actuator Of BPE1 & BPE2: 
 
1. Type : hydraulic 
2. Design : ASM 100-10-KSK 
3. Hydraulic system pressure : 100 bar 
4. Type of operation : control 
5. Positioning time : 10 sec 
1.29.9 Spray Water Pressure Reducing Valve- BD: 
 
1. Valve design : E 32 S 
2. Maximum valve stroke : 35 mm 
3. Design pressure : 280 ata 
4. Design temperature : 175 C 
5. Body material : 15 Mo3 
6. Nozzle material : 15 Mo3 
7. Maximum flow : 64.44 t/hr 
8. Seat diameter : 30mm 
9. Pressure drop : 41.53 ata [max] 
1.29.10 Actuator Of BD: 
 
1. Type : hydraulic [solenoid 
valve] 
2. Design : ASM 100-10-KCS 
3. Type of operation : open-close 
4. Positioning time : 10 sec 
 
 
 
 43 
1.29.11 Hydraulic Accumulator In Oil Supply Unit: 
 
1. Nominal volume : 30 litres 
2. Pressure rating : 200 bar3. Ambient temperature Min : 15 C 
1. Max : 65 C 
4. Operating gas : nitrogen only 
5. Bladder material : synthetic rubber 
6. Make : BOSCH 
 
1.30 CONDENSATE STORAGE TANK: 
 
No. for each unit : One. 
Capacity : 500 m3. 
Dimension of the tank : Dia. 8 mts. 
 Height 10.5 mts. 
 
 
 45 
 
 
 
1.31 SAFETY VALES – 
 TECHNICAL DETAILS 
 
1 Location 
Over Dea tank 
east / west 
Steam To 
Ejector 
Line 
Deaerator 
Extraction 
Line 
CEP Suction 
line 
Valve 
Gland 
Sealing 
Header 
Steam To 
Ejectors 
Line 
LP drain cooler 
2 Size 8" * 10 " 4" * 6" 6" * 8" 1.5" * 2" 4" * 6" 
LPHs -Water 
Expansion 
3 Set pr 7.0 ksc 8.5 ksc 6.8 ksc 1.5 ksc 3.5 ksc 8.5 ksc 28 ksc 
4 Type 1910 T/p2 
905 M 
/P3 
19100 / P3 1905/ 30 E 1/2"-1970 1905 M/P3 S 15030 
5 Temp 300 ºC 250 °C 342 /360 °C 44 /60 °C 45/60 °C 250 °C 200 °C 
6 Material 
C S SA 216 
wcb 
 CS 
7 Capacity 
4000 kg/hr of 
dry sat. Steam 
 
30782.7 
kg /hr 
220.6 
litres /min 
 3.95 
8 Open pr 6.8 ksc / 6.9 ksc 28.25 ksc 
9 Closing pr 5.4 ksc / 5.3 ksc 
 
 
 
 
 
 
 
 
 
 
 
 
 25 ksc 
 
 46 
TURBINE 
 STAGE – II 
OPERATION MANUAL 
 
 
 
 
 
 
 
 
 
 
 
CHAPTER – II 
 
 
 
GENERAL DESCRIPTION 
OF 
TURBINE & ITS AUXILIARIES. 
 
 47 
 
STAGE – II TURBINE OPERATION MANUAL 
CHAPTER – II 
GENERAL DESCRIPTION OF TURBINE & ITS ASSOCIATED SYSTEMS: 
 
2.1 Introduction OF Stage – II Turbine & ITS Associated Systems 
Turbines, condensers, regenerative heaters and other associated 
equipments were supplied and erected by M/s. BHEL. M/s. BHEL. supplied 
the Boiler Feed pumps. The Turbine is a three cylinders, tandem compound, 
double exhaust, condensing, single reheat type designed for high 
operating efficiency and maximum reliability. The motive force of rotating 
the turbine rotor is obtained from the expansion of high pressure and high 
temperature steam that is supplied by the boiler. The steam works on the 
modified Rankine cycle. Whenever steam flow varies the torque on turbine 
rotor changes, which in turn effects change in generator stator current, 
ultimately leading to changes in active power output. The condenser is of 
surface type. It is of single shell and rectangular in construction and has 
divided water box. In the condenser the steam is condensed by means of 
circulating water supplied by circulating water pump. M/s Mather and Platt 
supplied the circulating water pumps. The hot circulating water from the 
condenser is sent to Natural draught cooling tower where hot water is 
cooled by the natural flow of air. The main condensate collected at the 
condenser hotwell is pumped by condensate extraction pump and sent to 
Deaerator via LP heaters. At Deaerator, the oxygen present in the main 
condensate is removed by means of thermal deaeration. The deaerated 
water is pumped by Boiler feed pump and sent to boiler drum via HP 
heaters. 
 
 
 
 48 
2.2. Main Turbine: 
The turbine of the second stage Units IV to VII is three cylinders, 
double exhaust, condensing, single reheat, regenerative axial flow, tandem 
compound reaction type. It has High pressure (HP), Intermediate pressure 
(IP) and Low pressure (LP) cylinders. The HP cylinder is of single flow pattern. 
Both IP and LP cylinders are of double flow type. 
HP cylinder consists of 25 reaction stages and IP cylinder 20 double 
flow reaction stages. LP cylinder consists of 8 double flow reaction stages. 
Superheated steam is received from the boiler through two main 
steam lines. Each main steam line has a combined HP stop valve and HP 
control valve. Two transfer lines take the steam from the HP control valves to 
the HP cylinder on left and right. The steam flow in the HP cylinder is from 
Generator end to HP cylinder pedestal end. 
The exhaust steam of HP cylinder reaches reheaters arranged in two 
stages located in the boiler through two cold reheat lines. These cold 
reheat lines are provided with swing check valves to prevent the steam 
from the reheaters flowing back into the HP turbine in case of turbine trip. 
The steam coming from the reheater is taken to IP cylinder through 
two hot reheat lines through two combined reheat stop and control valves. 
The exhaust from the IP cylinder is taken from eight points, which join 
together to form two cross-around pipes leading to LP cylinder. 
Six extractions are taken from the turbine, three for low-pressure 
heaters, and one for the Deaerator and two for the high-pressure heaters. 
The individual turbine rotors and the generator rotor are connected 
by rigid couplings. The rotor as a coupled system rotates in six journal 
bearings out of which the bearing between HP and IP cylinder is a 
combined journal cum thrust bearing with tilting pads on both sides. 
 
 
 
 
 49 
2.3. Condenser: 
The condenser, which is surface type, is of single shell and rectangular 
in construction. It is rated to operate at a pressure of 0.1033 ata. The pattern 
of exhaust steam flow is downward with an upward flow in air-cooling 
section. The number of flow passes of circulating water is two. 
It has a divided water bow to enable part load operation (50%) of the 
unit. The circulating water coming through two cold water pipes at a 
temperature of 34 deg C enters the two water boxes at their bottom. The 
water flows in two passes and leaves the water box at the topside through 
two hot water pipes at 42.6 deg C. The condenser contains 17,668 numbers 
of stainless steel tubes (SSTP 316) of 25.4 mm outside diameter and 
0.7112mm thickness. 1,240 numbers of tubes are provided at the Air-cooling 
zone. The condenser is supported on 24 numbers of springs at its bottom 
and its neck is connected to the bottom of the LP cylinder. The exhaust 
steam flows downward to envelop all the bundles and then flows upward 
towards air suction pipe in the air-cooling zone. Air and non-condensing 
gases are extracted by one of the 2 ejectors normally in service, through 
the holes provided in air suction pipe. 
The system water losses for thermal cycle are made up at the hot 
well. 
2.3.1 Condenser On Load Tube Cleaning System: 
The performance of a Steam Power plant depends upon the 
condenser vacuum. Condenser vacuum depends on the cleanliness of the 
condenser tubes. Fouling and scaling in the condenser tubes reduce the 
heat transfer rate and hence the vacuum in the condenser tends to be 
poor. To keep the condenser tubes clean, „Condenser on load tube 
cleaning system‟ is installed. It consists of a ball vessel into which the balls to 
be kept in circulation are introduced initially. The ball recirculation pumps 
circulate these pumps through the condenser tubes on both sides. The balls 
after passing through the respective monitors are injected into the inlet 
water pipes of the condenser. They are carried by the circulating water to 
 50 
the condenser tubes from the inlet water boxes and then the balls reach 
the reversing chamber. Later they pass through the second pass of the 
condenser tubes and reach the outlet water boxes. These balls are carried 
into the outlet water pipes. Two ball separators are located in the 
condenser outlet water pipes and the balls which get trapped in the ball 
separator are then collected in a transverse channel, these balls are 
extracted along with the circulating water to form suction for the 
recirculatingpump. 
Normal cleaning balls used are of type soft-NTO-S and of diameter 27 
mm. Abrasive cleaning balls used are of type NTO-A and of diameter 26 
mm. 
Separate system is provided for A and B side of the condenser. 
2.4. Water Treatment Plant/ Stage-II 
Raw water for the stage-II water treatment plant is obtained from 
three bore wells named as E, F and G each of capacity 270 cubic m/hr all 
connected in parallel. There is an interconnection in the common supply 
line so that the raw water can be exchanged between stage-I and stage-II 
water treatment plants. Two raw water pumps each of capacity 150 m3, 
one in service and other as reserve serve as suction points for the three 
numbers of raw water pumps. They are of 200-m3/hr capacity and are 
capable of developing 4.5-ksc pressure. Out of the three, two will be in 
service and the third will be standby. The first treatment stage encountered 
is pressure sand filter and they are in 3 number. Pebbles, sand and crushed 
gravel serve as filtering mediums here and suspended matter is removed. 
The water after this stage is known as clarified water. It is followed by 3 nos. 
of weak acid cationic filter and the resin is CCXO-9. Potassium and sodium 
metallic radicals are removed here. The third treatment stage is „strong acid 
cationic filter‟ in which the resin T42H+ is used. Metallic radicals of calcium 
and magnesium are removed and this stage also has 3 vessels. Fourth stage 
treatment is the removal of carbon-di-oxide in two numbers of degasser 
towers,, each equipped with to air blowers of capacity 4,400m3/hr and 
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capable of developing 100 mm of water column pressure, one in service 
and other as standby. The degassed water is let into two numbers of 
storage tanks, each of capacity 100m3. The pressure which was provided by 
the raw water pump is sufficient for bringing the water up to this point. For 
passing the water through further treatment stages, the necessary pressure 
is provided by three numbers of degassed water pumps, two in service and 
one as reserve each of capacity 110 m3/hr and a pressure rating of 5 ksc. 
Three nos. strong base anion (primary) with A36MP resin in which all acidic 
radicals except silica are removed forms the fifth stage treatment. Three 
vessels containing A27MP resin in which silica removal is done is the 
penultimate stage. Final treatment is given in 3 numbers of mixed bed 
exchangers, which contain both the resins A27MP and T42H+. The treated 
water is stored in 3 nos. of DM water tanks each of capacity 500 m3 and the 
treated water can also be exchanged between the two plants. 3 nos of DM 
water pumps each of capacity 80m3/hr and 10 Ksc rating, two in service, 
one as reserve, pump the water through 2 mains. One main is going to the 
condensate storage tanks of Units 4 and 5 and the other main to the 
condensate storage tanks of Units 6 and 7. Each CST is also of capacity 500 
m3. The water treatment plant of stage-II has facilities for receiving, storing, 
diluting and supplying Hydrochloric acid and sodium hydroxide used for the 
regeneration of cationic and anionic resins respectively. It has an effluent 
treatment facility as well. The plant has flexibility of operation as all other 
streams are interconnected. DM water has a quality of 0.1 ppm „total 
dissolved salts‟. Capacity of the plant is 160 tonnes of treated water per 
hour. 
2.5 Make-Up Water System: 
The system water losses in the thermal cycle are made up at the 
condenser through a surge tank of capacity 50 m3. DM water supplied by 
the water treatment plant is stored at 2 Condensate storage tanks (CST) of 
each capacity 500 m3. The DM water stored in these tanks are also used for 
the following purposes: 
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 Make-up water for Auxiliary Cooling water (ACW) overhead tank of 
capacity 15 m3. 
 Make-up water for Stator water tank of capacity 5 m3. 
 Initial filling up of Deaerator. 
 Initial filling up of Boiler. 
 Make-up water for Surge Tank. 
These tanks are provided with 3 pumps called as „condensate 
transfer pumps‟. Pump-C will be normally in service and others (A and B) are 
reserve. This is a single stage end suction centrifugal pump. Pump A and B 
are of same capacity (180 m3/hr, dis press: 14 ksc, 2970 rpm, 110 KW) and 
Pump-C has the capacity of 200 m3/hr (dis press: 5.5 ksc, 1475 rpm, 45 KW) 
2.6. Main Condensate System: 
The main condensate collected at the hot well of the condenser is 
pumped to deaerator by means of Condensate Extraction Pump (CEP). 
There are 2 CEPs each of 100 % capacity. One pump is to be kept in service 
and the other is intended to be standby. This is a 6 stage, vertical, 
centrifugal pump of canister type. The rated capacity of the CEP is 678 
m3/hr at a design differential pressure of 22.5 ksc. The pump is provided with 
an airline connected to the steam space of the condenser. It is also 
provided with a gland sealing line for avoiding air entry into the condenser. 
The water for the gland sealing is supplied from the discharge header of 
CEPs and a surge tank provides the reserve facility. The CEP drive motor 
rated at 600 KW, runs at 1482 rpm and is provided with 6.6 KV power supply. 
The main condensate delivered by the CEP flows through the Main 
Ejectors, Gland Steam Condenser, LP drain cooler and regenerative Low 
Press Heaters 1,2 and 3 to reach the top of the Deaerator heater finally. The 
main condensate which is leaving the Gland Steam Condenser at 48 degC 
is heated to 120 degC in LP heaters. Necessary bypass lines are also 
provided for the Main Ejectors, Gland Steam Condenser and all the 3 LP 
heaters. A condenser recirculation line is also provided after Gland Steam 
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Condenser to maintain a minimum flow through CEP, Main Ejectors and 
Gland Steam Condensers. 
This system also supplies condensate for the following auxiliary 
purposes. 
1. Spray water for the LP B/P system. 
2. Exhaust hood spray water system. 
3. Chemical feeding 
4. Quenching the vapours of the flash boxes. 
5. Vacuum breaker line sealing. 
6. Gland sealing of valves, which are connected with the condenser. 
7. Condenser constant level vessel filling. 
8. Main Ejectors‟ syphons – initial filling. 
9. Gland sealing water for condensate exhaust pumps. 
2.7. Circulating Water System: 
A common circulating water pump house is located in the western 
end of the power station and there are 11 single stage vertical mixed flow 
pumps. Each pump is of capacity 16,500m3 /hr at a delivery head of 27.5 m 
of water column and is coupled to a motor of capacity 1760 KW and 
running at 496 rpm. 
Two circulating water pumps can meet the needs of the condenser 
of one unit while three pumps are kept as standby for all the four units. Each 
one of the standby pumps is located in between the pairs of pumps. The 
cold circulating water stored in Forebay is made available to the circulating 
water pumps through suction pits. The delivery of each pump is supplied 
through a steel pipe with a butterfly discharge valve. The pair of the 
discharge pipes from the two pumps of a unit join a cold water pipe and 
this pipe can also be fed from the concerned standby pump. This cold 
water pipe takes the cold circulating water to the condenser and supplies it 
in two intake pipes just before entry to the condenser. These two intake 
pipes join the front water boxes at their bottom. 
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The circulating water entering the water box flows in two passes inside 
the condenser. The reversing chamber at the rear connects both water 
passes. Two outlet pipes from the topside of the front water boxes join a 
common hot water pipe for taking hot circulatingwater to the cooling 
tower. 
Makeup to the circulating water system is from an artificial lake of 
capacity 1,708,605 m3 located in the North West of the power station, 
which in turn gets its water supply from Mines-II through four pipe lines. Major 
water losses in the circulating water system are 
i. Blow down to Ash disposal pump house, 
ii. Evaporation loss in the cooling tower, 
iii. Drift loss in the cooling tower. 
The make up water is drawn from the lake to the forebay through a 
line with level control valve. This line can also receive water directly from the 
two make up water lines from Mines-II.Normal storage at the lake is sufficient 
for a period of 6 days for all the seven units. 
2.7.1. Chlorination: 
The circulating water flowing through the condenser contains various 
vegetable and animal microorganisms. Some of them will get accumulated 
and reproduce themselves inside the tube walls. Due to this accumulation, 
the flow of circulating water inside the condenser will be reduced which in 
turn results in reduction in the rate of heat transfer and hence the vacuum 
in the condenser. Chlorination of this water kills the microorganisms and 
hence they lose their ability to stick to the inner tube walls. 
The chlorination plant located nearer to the circulating water pump 
house has three units each of 120 kg/hr. dosing capacity. Liquid chlorine 
drawn from the chlorine Tonners is piped to an evaporator cylinder, which is 
immersed in a controlled temperature hot water bath. Liquid chlorine is 
evaporated into gas and then supplied to an Ejector through a chlorine 
metering device called as “Chlorinator”. 
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Raw water is supplied by a booster pump and the water flow through 
the ejector mixed with the raw water is dosed through diffuser pipes at the 
forebay just at the entry of cold circulating water from the open channel. 
Chlorination is carried out periodically to maintain an optimum level of 
chlorine in the water so that it is effective. 
2.7.2. Dozing of Organo Phosphate: 
Calcium Carbonate (Ca CO3) is the most common scale found in the 
circulating water system. It is normally results from the break down of 
calcium bi carbonate, a naturally occurring soluble salt in water. The rate of 
calcium carbonate break down increases with PH and temperature. In the 
condenser, formation of scale is severe at high temperature regions. 
Treatment of water with organo phosphate is done to minimize the scaling 
by avoiding precipitation of salts. HEDP (1 hydroxy ethylidine, 1 
diphosphonic acid) is dosed along with zinc hydroxide and Benxe tirazole 
as copper corrosion inhibitors. Additional benefit due to this dosing is the 
reduction in the circulating water blow down. 
2.8. Cooling Towers: 
Four natural draught cooling towers are located at the South West of 
the power station. The shape of the tower is circular in plan and hyperbolic 
in profile. The empty shell does the function of evolving draught, i.e., flow of 
air. The entire shell of the tower is supported by 72 diagonal columns of 
diameter 900mm.the inner diameter of the tower is reduced from 94.42m at 
sill level to 53.9 m at its neck at an elevation of 89 m. Then it is increased to 
59.4 m at the top elevation of 124 m. eighteen layers of R.C.C louvers 
constitute the internal fill in the cooling tower. They are supported by 
precast columns and beams. 
Hot circulating water leaving the condenser flows in a single hot 
water pipe towards the cooling tower. From the hot water pipes, hot water 
flows up to the middle of the basin through two hot water ducts. From the 
basin floor, the hot water rises through risers and the hot water enters 
distribution network at 10 metres elevation. The hot water from each riser is 
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distributed with a main duct and a branch duct and thereafter through 
A.C.pipes. These pipes are fitted with nozzles and sprayers. Total number of 
sprayers in the tower is 8752. 
The basin for collecting cold water has a partition wall for isolating 
50% of the tower in service for maintenance work. Wind baffles are 
provided in the space between the top of the basin and the bottom of the 
fill in order to avoid a break through of air during strong winds. The cooling 
capacity of the cooling tower is 30000 m3/hr and the range of cooling is 8.5 
deg °C. 
2.9. Fire protection system: 
The „Fire Protection System‟ comprises of a Fire Hydrant System and a 
High Velocity Water System (HVW) with their related pump sets. The hydrant 
system provides a convenient source of water supply for fire fighting 
purpose inside the Thermal Power Station premises in the event of a fire out 
break. HVW system sprays water on to the risk it protects when it is actuated 
manually in case of outbreak of a localized fire. These two systems are 
interconnected. 
The fire hydrant system id provided with three hydrant pumps out of 
which two are electrically driven while the third is diesel engine driven. 
These pumps feed a common header, which feeds the hydrant lines 
leading to various hydrant circuits in the Thermal Power Station. In the event 
of a fire outbreak the water under pressure can be tapped from the outlets 
called as hydrant points and directed on the to seat of the fire manually by 
means of the hoses and nozzles provided, the water for the fire hydrant 
system is drawn from the forebay of the circulating water pump house. 
The HVW spray system consists of an electric motor driven pump and 
a diesel engine driven pump and these two pumps feed the HVW system. 
The system pressure is maintained at 9.8 ksc by a hydro pneumatic 
tank. This tank is pressurized vessel. The top of the tank is connected to an 
air compressor while the jockey pump feeds the tank with pressurized water 
from the bottom. In the event of a minor system leakage in either the 
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hydrant system or in the HVW system, the make up water under pressure will 
be fed from this tank so as to sustain the system pressure. The water level in 
the tank is maintained by the jockey pump and the pressure in the tank is 
maintained by means of the compressor. 
The HVW system protects the Main Oil Tank, Lub oil Canal – I and Lub 
Oil canal- II. Each hazard is protected by a spray system provided with a 
network of piping all around. Spray nozzles are located to cover the 
complete surface area of the hazard by a uniform spray. The high velocity 
water is tapped off from the HVW spray mains and is supplied through 
“Deluge Valve”. The hazards are provided with smoke detectors and Heat 
detectors. These detectors and Manual call points are in parallel to send 
signal to the fire alarm panel in the event of a fire. On seeing the alarms, the 
release system of the respective Deluge valve can be initiated manually to 
provide the HVW spray on the hazard. 
2.10. Deaerator: 
In order to avoid corrosion of internal surfaces all the heat transfer 
elements and pipelines in the feed water path boiler water wall tubes and 
drum, the gases dissolved in the feedwater, are removed in the deaerator. 
Operation of the Deaerator is based upon the fact that the gas solubility in 
the water decreases as the temperature rises. If the water is heated up to 
the saturation temperature and kept at this temperature for a sufficient 
time, all gases can be removed and vented to atmosphere. In order to 
increase the deaerating efficiency, the water is broken up into small 
droplets through a system of spray nozzles and perforated trays. 
The deaerator is of combined spray and tray type and is erected at 
27.0 m elevation. It consists of a horizontal deaerating header and a 
horizontal deaerated water storage tank.The header is connected to the 
storage tank through 3 numbers of pipes. The deaerator is operated on a 
variable pressure mode. 
There are five perforated trays in each of the two stacks in the 
deaerating header. The main condensate enters the header at the top and 
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is divided into small droplets by means of spray nozzles. Then it is distributed 
uniformly over the trays. Fourth extraction steam of turbine is used for 
deaeration. Cold reheat steam and auxiliary steam bus provide necessary 
reserve supply of steam for the deaerator. Two safety valves are provided 
on the top of deaerator storage tank in addition to the four safety valves in 
the steam supply line. 
The operating parameters of deaerator are 6.6 ata and 161.9C. 
Normal water level of deaerator is 585 mm above the geometric center line 
of the storage tank. The deaerating steam at initial start up periods is 
received from the auxiliary steam bus. 
2.11. Boiler Feed Pumps: 
Each unit is provided with three boiler feed pumps of 50% capacity 
each. Two pumps are in normal service and the other is intended to be at 
standby. These pumps are located at 4.5 metres elevation inside the turbine 
hall. 
The feed pump is a 6 stage centrifugal pump. The capacity of the 
pump is 423m3/hr. Its differential pressure is 222.2 kg/cm2 at a speed of 5300 
rpm. An inter-stage tap off after the third stage is taken to feed the two de-
super-heaters of the reheater meant for the reheated steam temperature 
control. 
Feed pump itself is fed by the booster pump, this is a single stage 
double centrifugal pump and is also driven by the feed pump moor, 
coupled to the other end shaft of the motor the booster pump has its 
suction from the Deaerator and delivers the water at a higher pressure 
thereby providing the net positive suction head (NPSH) for the feed pump. 
The differential pressure of the booster pump is 10.4 ksc. 
The 6.6kv feed pump drive motor is of capacity 4000kw with a rated 
speed of 1485 rpm. The power is transmitted from the motor to the feed 
pump through a variable speed hydro coupling. It consists of a step up 
herring bone gear of gear ration 131/36 followed by the hydro-coupling. 
The variable speed for the feed pump is achieved by positioning of a 
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pneumatically operated scoop tube. The necessary working oil for the 
hydro coupling is supplied by a working oil pump. Requirement of lub oil for 
the bearings of the motor, the feed pump and the bearings of the hydro 
coupling is met by a lub oil pump. Both the working oil pump and the lub oil 
pump are mounted on a single shaft and are driven by the input shaft of 
the hydro coupling through a spur and bevel gear train. These two pumps 
draw oil from a common sump at the bottom of the hydro coupling and 
supply oil for the hydro coupling and lubrication of various bearings 
separately. Another motor driven lub oil pump is also provided to supply lub 
oil during start- up, tripping and break down periods. 
 A pneumatically operated recirculation valve is provided on the 
recirculation line to ensure a minimum flow of 100 m3/hr through the feed 
pump. The feed pump is provided with mechanical seals at both the ends 
and a seal water cooler is provided to cool the seal water with the help of 
the auxiliary cooling water. 
In order to keep the reserve / idle feed pump in warmed up condition 
so as to avoid thermal shock, a small quantity of feed water is continuously 
allowed to flow to the flash box (and then to the condenser). This line is 
provided with a pneumatic, valve and it is called the „ warming up line „. By 
this line, the temperature of the casing and the internal assembly is 
maintained at the operating value. 
The feed pumps discharge the feed water to the boiler drum through 
two high pressure heaters, feed water regulating station and two stages of 
the economizer. 
2.12. Ejectors: 
The function of the steam air ejector is to create vacuum inside the 
condenser and further maintain it by continuously extracting air and non- 
condensing gases. There are two main ejectors and one starting or pilot 
ejector. 
Pilot ejector is used exclusively for initial building up of vacuum in the 
condenser. Main ejectors take up the work of raising the vacuum further. 
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After normal vacuum is achieved out of the two main ejectors, one will be 
in normal in service and the other will be a stand by. 
Ejectors operate based on the principle of Nozzles cum diffuser. When 
flow of steam at design pressure is effected through a nozzle cum diffuser, 
high vacuum is created in the chamber in between the nozzle and the 
diffuser due to increased velocity of the steam. Since this chamber is kept in 
communication with the air line from the condenser, extraction of air and 
non-condensing gases from the condenser takes place. 
Pilot ejector is dingle stage type and the main ejectors are of three 
stage type, the operating steam fro these ejectors is supplied from the 
Auxiliary steam bus at 16 kg/cm2.in the case of pilot ejector, the exhaust of 
the one stage becomes suction for the next stage. The cooling medium 
used to condense the operating steam in the condensing chambers of all 
the stages of the main ejectors is the main condensate flowing through 
inverted „U‟ tubes. The drain condensate collected in each stage is 
cascaded so as to reach the condenser hotwell finally through the flash 
box. 
2.13. Gland Sealing Steam System And Leak Off Steam: 
During the normal service of the unit, the operating steam admitted 
into HP and IP cylinders of the turbine tries to leak off through the small 
clearances between the rotor and casing at both ends. Labyrinth glands 
are provided for the purpose of minimizing the steam leakage through the 
spindle, long and short packing seal strips laid alternatively over the grooves 
of the rotor give the improved performance of minimizing the steam 
leakage. In the case of the LP cylinder leakage of air into the condenser 
through both ends of the rotor takes place since the steam leaving the last 
stage of LP cylinder is having a sun atmospheric pressure of 0.1033 ata. 
Hence a rotor gland sealing steam system is warranted it supplies steam for 
sealing at a pressure just above the atmospheric and this acts as a seal 
against the entry of air at both ends of LP rotor. During the period of initial 
vacuum raising in the condenser, the sealing steam becomes necessary for 
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the ends of the HP and Ip cylinders also as there will not be any operating 
steam inside HP and Ip cylinders. 
During normal service of the unit, the spindle leak off steam from the 
HP cylinder, admission end is collected in four phases. The steam collected 
after I phase of pressure reduction is diverted to cold reheat steam. The 
steam collected after II phase of pressure reduction is diverted to IP cylinder 
exhaust. The steam leaking through after III phase of pressure reduction 
becomes self-source of steam for sealing of LP cylinder ends. The steam 
leaking past after IV phase of pressure reduction is collected by Gland 
steam condenser. 
Similarly the spindle leak off steam from HP cylinder Exhaust end is 
collected in 3 phases. The steam leaking after I phase of pressure reduction 
is diverted to IP cylinder exhaust and the steam leaking after II phases of 
pressure reduction also becomes the self source steam supply for sealing of 
LP cylinder ends. The steam leaking after III phase of pressure reduction is 
collected by Gland steam condenser. 
In the case of LP cylinder, the sealing steam is supplied at both ends