Steam Condense Performance and Loss Diagnostic
Pichai Chaibamrung
IntroductionThis report is intent to guide engineer, operator, or
technician to diagnose poor condenser vacuum in thermal power plant. A slightly increase condenser pressure result in a huge loss due to increasing plant heat rate. This guidance can be help involving person to fast and accurately analyze the root causes of the losses
Surface CondenserShell and tube heat exchangerConnect to steam turbine exhaust To convert low energy exhaust steam to water to
reuse in power boilerOperating below atmospheric pressure Use cooling water to extract heat from low
energy exhaust steam
Important of condenser pressureMore vacuum pressure more useful energy
convertedMore useful energy converted, less raw energy is
need
T
S
Lowering condenser pressure more energy converted in steam turbine
Expected Design Condenser Pressure
Steam load
Q -Is your current operating pressure is good? -How you know?
A :You have to compare with expected design pressure at each load and specific cooling water temperature
Example, Steam load 72 T/H Cooling water inlet temperature 32 CCurrent operating pressure -0.86 bargDesign operating pressure -0.88 barg
What is the root cause?
Current operating
Design operating
Poor vacuum, What is result from?Less cooling water flow rateFouling on tubeIncondensable gas in condenser shellOver heat duty
How do we know what the cause is ?
DefinitionTI = exhaust steam temperature TO = condensate temperatureT1 = cooling water inlet temperatureT2 = cooling water outlet temperatureTI – T2 = terminal temperature different (TTD)T2-T1 = temperature rise (TR)TO - TI = sub-cooling temperature (TS)
Less cooling water flow rate
Fouling on tube
Incondensable gas in condenser shell
Over heat duty
Conclusion