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Condensate and

FW system

1

T K Ray

Sr. Faculty PMI NTPC

raytk@rediffmail.com

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Condensate System

Condenser

CEP

LP Heaters Deaerator

Feed Water System

Boiler Feed Pump

HP Heater

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High Pres, high temp (170 bar,High Pres, high temp (170 bar,

540 C) steam from boiler flows to540 C) steam from boiler flows toturbineturbine

As the steam passes throughAs the steam passes through

turbine, thermal energy isturbine, thermal energy is

converted into mech. energy.converted into mech. energy.

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1

2

3

4

ESV

1

CV1

CRH

IPSV1IPCV 1

FROM RH

TURBINE LAYOUT Rotating mag. field is produced by giving DC

excitation to rotor thro carbon brushes.

Rotating mag. field cuts the stationary

conductors placed in the stator. Volt. is

generated at the stator terminals. If gen.

circuit is closed current starts flowing.

4

GENERATOR

EXCITER

CONDEN

LPBYPASS

TO LP HEATERS

HPT 1X17IPT

2X12

LPT

2X61: MS 170 bar, 540 C

2: CRH 45 bar, 340 C

3: HRH 40 bar, 540 C

4: IPT Exh. 7 bar, 168 C

T K Ray PMI NTPC

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After the useful work isAfter the useful work is

produced in turbine, theproduced in turbine, thesteam (~10steam (~10 kPakPa abs, 88 %abs, 88 %

VF) is exhausted toVF) is exhausted to

condensercondenser

CW is circulated inCW is circulated in

5T K Ray PMI NTPC

condensercondenser

Lowering the temp of heatLowering the temp of heat

rejection improves cyclerejection improves cycleefficiencyefficiency

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STEAM EJECTORS

Motivesteam

Convergentdivergent

diffuser

Nozzle

condenser

Non condensable gases andwater vapor from condenser

Dischargeto

6

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STEAM EJECTORS

After

condens

er

vent

drain

Non condensible gases andwater vapour from condenser

Motive

steamFirst stageejector condensate

Multi stage ejector system

Motivesteam

SecondstageejectorInter

condenser

drain

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LRVP

Suction port

Casing

Discharge port

Impeller

Gas vapour

mixture Liquid ring8

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LRVP

Separator

vent

Non condensable gases and

water vapor from condenser

Makeu

Coolingwater

Liquid ring vacuum pump system

Seal water

LRVP

Seal cooler

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LRVP WITH AIR OPERATED EJECTOR

Separator

ventNon condensiblegases and watervapour fromcondenser

P

Air ejector

Coolingwater

Liquid ring vacuum pump system

Seal water

LRVP

Seal cooler

Makeup

T

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AIR OPERATED EJECTOR

Ejector protects the Liquid Ring Pump from cavitating, even

when warm water is used as the sealant. The air ejector boosts

the operating pressure of the Liquid Ring Pump to keep it out of

the range of cavitation.

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CONDENSER

Converts last stage steam of LPT to water

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CEP

Converts last stage steam of LPT to water

CONDENSER

CEP

GSC CPU DEAREATORLEVELCONTROL

CONDENSER

Minimum recirculation to condenser

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LPH

BLOCK DIAGRAM REPRESENTATION OFCONDENSATE FLOW THROUGH LOW

PRESSURE HEATERS

LPH1 LPH2 LPH3

CONDENSER CONDENSER CONDENSERCONDENSER

FROMCONDENSER TO

DEAREATOR

DRIPWATERDRIPWATER

DRIPWATER

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LPH

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LPH

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DEAERATOR

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Water Spray in Deaerator

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Water Spray in Deaerator

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Feed Water System

Feed Water System

1. Boiler Feed Pump

Motor driven BFP

Turbine Driven BFP

2. HP Heaters

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General Arrangement of BFP

Suction

Strainer

Feed Water

From D/A

To HPH. Recirculation to FST

BoosterPump

MotorMain

Pump

S S for

Main Pump

Hydraulic

Coupling 21

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HP HEATERS

HPH 6A

HPH 5BHPH 5A

HPH 6B

TO ECONOMISER

TO ECOCIRCULATION

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Variation of Feedwater Temperature and Enthalpy along the

FeedWater Heater

100

150

200

250

300

Temperature(C)

400

600

800

1000

1200

Enthalpy(kJ/kg)

Temperature

Enthalpy 6

5

4

3

21

DCGSC

0.0

K

D0.0

K

6.0

K

6.0

K

C

0 0

6 5 43 2 1

DC

GSC

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HP HEATERS

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HP HEATERS

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Labyrinth seal

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DEARATOR WITH STORAGE TANK