(Solved): Problem 3 (2 points) A power plant operates on a regenerative cycle with a closed feedwater heater ...
Problem 3 (2 points) A power plant operates on a regenerative cycle with a closed feedwater heater (CFH). Steam enters the first stage of the turbine at 10 MPa and 550 C and it is expanded to 1 MPa . At this point, part of the steam is redirected to the CFH. This steam leaves the CFH as saturated liquid and it is expanded to the condenser pressure using a throttle valve, after which it enters the condenser. The condenser operates at 25 kPa . Assume saturated liquid out of the condenser. On the other hand, the feedwater leaves the CFH at 10 MPa and 180 C . Assuming perfect isentropic efficiencies for all components, find: a) The thermal efficiency of the entire system. b) The water mass flow rate to produce a net power of 230 MW . Remember: a throttle valve is used to reduce pressure. Enthalpy is conserved in it. (Sol: a)
0.4;b)
209.45k(g)/(s))
