Condensate Cycle

CONDENSATE CYCLE

ANSHUL AGARWAL

ENGR (OPN)

POWER PLANT CYCLE

The Working fluid is Water.

Working principle is based on the Modified Rankine Cycle ( With Single Re- Heat )

The closed cycle consists of three intermediate cycles:

Condensate cycle

Feed Water Cycle

Steam Cycle

HPH 5

PSH

ECO

BFP

HPH6

FSHLTSHDRUM

CEP

FURNACE

IPT LPTHPT

R/H

LPH 1

GSC

LPH2LPH3DEA D/C

COND

LPH 1

GSC

LPH2LPH3DEA D/C

COND

CONDENSATE CYCLE

CEP

Sensible Heat addition to condensate extracted from condenser by CEP

Starts from Condenser and ends at De- Aerator

GSC, LPH 1,2,3 and Drain Cooler are the heat exchangers

Driving force is CEP

CONDENSER

Purpose:

Condense the steam leaving the turbine

Latent Heat of Condensation to be rejected.

Surface type, double pass with divided water box construction

Soft Water from CW pump house is used as cooling water to condense the steam

HOTWELL

Vessel where Condensate collects after condensation

CEP takes suction from Hotwell. So level Control is very important.

Temperature of Condensate is generally just below saturation temp of steam leaving the turbine.( Condensate Depression)

Fresh DM water make up is added hereBest temperature matching occurs as temp of working fluid is lowest hereMake up water can then pass through all the heaters

CONDENSATE EXTRACTION PUMP ( CEP)

PURPOSE:

•Extract condensate from the condenser ( hotwell) and feed it into the cycle.

•It is the driving force of the condensate cycle up to De- Aerator

2 x100 % capability pumps are provided.

1 in service and other as standby

Canister type vertical centrifugal pump with 5 stages

CONDENSATE EXTRACTION PUMP ( CEP)

CEP CONNECTIONS

TO GSC

LP BP SPRAY

GLAND SEALINGCST

CEP R/C

DOZING TANKS MAKE UP

CEP

GLAND STEAM CONDENSER (GSC)

PURPOSE:

•To quench the sealing steam coming out of last gland seal of HPT, IPT AND LPT.

•Also works as a heat exchanger, adding sensible heat to condensate.

Sealing steam after condensation forms drip which goes to LP flash box.

LOW PRESSURE HEATERS

•A Feed water heater is a component used to pre-heat water delivered to the boiler. Preheating the feedwater reduces the amount of energy needed to make steam and thus reduces plant operation costs. This improves the thermodynamic efficiency of the system.

CLASSIFICATION

PARALLEL FLOW

CROSS FLOW

COUNTER FLOW

HEAT EXHANGERS

In parallel-flow heat exchangers, the two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side.

In cross flow heat exchangers, heating medium is perpendicular to the medium being heated

In counter-flow heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is most efficient, in that it can transfer the most heat.

T 2

T 1

T 1

T 1

T 1

T 1

T 1

T 2

T 2

T 2

T 2

T 2

T2 > T1 COLD MEDIUM HOT MEDIUM

SHELL AND TUBE HEAT EXCHANGER

Two fluids, of different starting temperatures, flow through the heat exchanger. One flows through the tubes (the tube side) and the other flows outside the tubes but inside the shell (the shell side). Heat is transferred from one fluid to the other through the tube walls, either from tube side to shell side or vice versa.. In order to transfer heat efficiently, a large heat transfer area should be used, so there are many tubes. In this way, waste heat can be put to use..

CONDENSER

• Converts last stage steam of LPT to water


LPH3 GSC D/CLPH 1LPH 2

LP

FB

TO

D/A

FROM

CEP

EX-2EX-3GLAND STEAM

LPT 7TH STAGE

GSC D/CLPH 1 GSC D/CLPH 1

LPT 3rd STAGE

LPT 5TH STAGE


PURPOSE:

•Sensible Heat addition to Condensate

The condensate has higher density and hence is e inside the tubes.

LPH 3, LPH 2, LPH 1, DC AND GSC are all shell and tube type.


Each heater can be bypassed individually.

LPH 1 and D/C have a common by pass, as heating source in DC is drip of LPH 1

All the drips ultimately collect in LP flash box, from where it flows to hotwell.


DESIGN CONSIDERATIONS:

•Heat Load

•No of tubes

•Level of Drip

•TTD

•DCA

•Temperature rise

HEAT EXCHANGERS AT FULL LOAD

EXCHANGER SOURCE TEMP. OF SOURCE

GSC SEALING STEAM LEAK FROM LAST GLAND

D/C DRIP OF LPH 1 60.3

LPH 1 LPT- 7TH STAGE 62

LPH2 LPT- 5TH STAGE ( EX 2) 107

LPH3 LPT- 3RD STAGE ( EX-3) 200

Documents

Condensate Cycle