What is the best vacuum in steam turbine condenser?

30 mw 1case & 11stages An impulse turbine/live steam inlet t=482 degree centigrad & p=43 bar Q=120 ton/hr

 

> What is the best vacuum in steam turbine condenser?

> 30 mw 1case & 11stages An impulse turbine/live steam inlet t=482 degree centigrad & p=43 bar Q=120 ton/hr

Theoretically the lower the better. If possible near full vacuum. But the practical limit is to keep the condensate temperature (T_sat) to be as the following:<pre>
T_sat =T_cwoutlet + TTD </pre>
without a need to reduce heat load to be sent to the condenser. TTD is condenser performance indicator that stands for Terminal Temperature Difference, i.e the diff between T_sat and condenser water outlet temp. (T_cwoutlet).

E.g. If Cw outlet temp. is 40 C and T_sat is 43 C, then the TTD is 3 C.

So the most useful single indicator to see how good a condenser is operated and managed is by looking at Delta TTD (Actual TTD- Commissioning TTD) for the same heat load. Ideally Delta TTD shall be zero, indicating the condenser performs as good as the commissioning.