1. Reconsider the cycle of Problem 8.46, but include in the analysis that each turbine stage and the pump has an isentropic efficiency of 85%.
2. For the cycle of Problem 8.47, investigate the effects on cycle performance as the feedwater heater pressure takes on other values. Construct suitable plots and discuss.
3. Water is the working fluid in an ideal regenerative Rankine cycle with one closed feedwater heater. Superheated vapor enters the turbine at 10 MPa, 4808C, and the condenser pressure is 6 kPa. Steam expands through the first-stage turbine where some is extracted and diverted to a closed feedwater heater at 0.7 MPa. Condensate drains from the feedwater heater as saturated liquid at 0.7 MPa and is trapped into the condenser. The feedwater leaves the heater at 10 MPa and a temperature equal to the saturation temperature at 0.7 MPa. Determine for the cycle
(a) the rate of heat transfer to the working fluid passing through the steam generator, in kJ per kg of steam entering the first-stage turbine.
(b) the thermal efficiency.
(c) the rate of heat transfer from the working fluid passing through the condenser to the cooling water, in kJ per kg of steam entering the first-stage turbine.