condensate cycle
TRANSCRIPT
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
LOW PRESSURE HEATERS
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
LOW PRESSURE HEATERS
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.
LOW PRESSURE HEATERS
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.
LOW PRESSURE HEATERS
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