Cond - Fw System

Condensate and FW system
T K Ray Sr. Faculty – PMI NTPC

[email protected]

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• Condensate System • Condenser • CEP • LP Heaters • Deaerator

• Feed Water System • Boiler Feed Pump • HP Heater

T K Ray PMI NTPC

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• High Pres, high temp (170 bar, 540 C) steam from boiler flows to turbine • As the steam passes through turbine, thermal energy is converted into mech. energy.

T K Ray PMI NTPC

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TURBINE LAYOUT
IPSV1IPCV 1 FROM RH

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

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ESV CV1 1 3

generated at the stator terminals. If gen. circuit is closed current starts flowing.
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2 CRH

GENERATOR HPT 1X17 IPT 2X12 LPT 2X6 TO LP HEATERS CONDEN LPBYPASS

1: 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

EXCITER

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• After the useful work is produced in turbine, the steam (~10 kPa abs, 88 % VF) is exhausted to condenser • CW is circulated in condenser • Lowering the temp of heat rejection improves cycle efficiency
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STEAM EJECTORS
Nozzle Discharge to condenser
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Convergent divergent diffuser

Motive steam

Non condensable gases and water vapor from condenser

STEAM EJECTORS
vent condenser drain

Non condensible gases and water vapour from condenser Inter Motive steam condenser First stage ejector condensate drain

After

Second stage ejector

Multi stage ejector system

Motive steam
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LRVP
Suction port Discharge port Casing

Impeller

Gas vapour mixture

Liquid ring 8

LRVP
vent Non condensable gases and water vapor from condenser Separator Makeup

Cooling water Seal cooler

LRVP Seal water

Liquid ring vacuum pump system
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LRVP WITH AIR OPERATED EJECTOR
Non condensible gases and water vapour from condenser Air ejector vent

Separator P Makeup

Cooling water Seal cooler

LRVP T Seal water

Liquid ring vacuum pump system
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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 CEP
CONDENSER

GSC

CPU

DEAREATOR LEVEL CONTROL

CONDENSER

Minimum recirculation to condenser

T K Ray PMI NTPC

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LPH
BLOCK DIAGRAM REPRESENTATION OF CONDENSATE FLOW THROUGH LOW PRESSURE HEATERS

LPH1 FROM CONDENSER

LPH2

LPH3 TO DEAREATOR

DRIPWATER CONDENSER

DRIPWATER CONDENSER

DRIPWATER CONDENSER

CONDENSER

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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

T K Ray PMI NTPC

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General Arrangement of BFP
Feed Water From D/A Suction Strainer To HPH. Recirculation to FST

Motor Booster Pump S S for Main Pump
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Main Pump

Hydraulic Coupling

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HP HEATERS

HPH 6A

HPH 6B

HPH 5A

HPH 5B

TO ECONOMISER TO ECO CIRCULATION

T K Ray PMI NTPC

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Variation of Feedwater T emperature and Enthalpy along the FeedWater Heater
300 250
T e m p e ra tu re ( C )

Temperature Enthalpy
5 6

1200 1000 800
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E n th a lp y (k J /k g )

200 150 100
GSC DC 2 1

3

600 400 200 0

50 0

6

5

4

3

2

1 GSC

0.0 K

0.0 K

D

DC

C

6.0 K

6.0 K

HP HEATERS

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HP HEATERS

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Labyrinth seal

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DEARATOR WITH STORAGE TANK