(Solved): A power plant operates on a regenerative vapor power cycle with one open feedwater heater. Steam en ...

A power plant operates on a regenerative vapor power cycle with one open feedwater heater. Steam enters the first turbine stage at $$12\mathrm{MPa},560^{?}\mathrm{C}$$ and expands to $$1\mathrm{MPa}$$, where some of the steam is extracted and diverted to the open feedwater heater operating at 1 MPa. The remaining steam expands through the second turbine stage to the condenser pressure of $$50\mathrm{kPa}$$. Saturated liquid exits the open feedwater heater at $$1\mathrm{MPa}$$. The net power output for the cycle is $$330\mathrm{MW}$$. Assume that both turbine stages and both pumps have an isentropic efficiency of $$90\%$$. Determine: (a) the percent cycle thermal efficiency. (b) the mass flow rate into the first turbine stage, in $$\mathrm{kg}/\mathrm{s}$$. (c) the rate of entropy production in the open feedwater heater, in $$\mathrm{kW}/\mathrm{K}$$.