# Question: a rankine cycle operates with and without a feedwater heater...

###### Question details

*A Rankine cycle operates with and without a feedwater
heater. Pressure of the steam at the inlet is 8 MPa and T= 440 C.
Pressure of the condenser is 0.006 MPa. The steam expands to 0.6
MPa after the 1*^{st}*-stage turbine and a
certain percentage of steam is turned into an open feedwater heater
of pressure 0.6 MPa. At the exit of the feedwater heater, Saturated
liquid is at 0.6 MPa. The rest of the steam expands after
2*^{nd}*-stage turbine and streams to the
condenser that is operated at 0.006 MPa. The
1*^{st}*-stage turbine,
2*^{nd}*-stage turbine, and pump have 80%
isentropic efficiency.*

*Find the thermal efficiency without the feedwater heater (Hint: mass flow at state 2 is zero and treat the two pumps as one pump).**Find the heat added to the boiler (kJ/kg) without the feedwater heater.**Find the thermal efficiency with the feedwater heater.**Find the heat added to the boiler with the feedwater heater (kJ/kg).*