Example-10 (Regenerative Rankine Cycle) Consider a reheat-regenerative vapor power cycle with two feedwater heaters, a closed feedwater heater and an open feedwater heater. Steam enters the first turbine at 10 MPa, 500°C and expands to 0.8 MPa. The steam is reheated to 440°C before entering the second turbine, where it expands to the condenser at a pressure of 0.007 MPa. Steam is extracted from the first turbine at 2 MPa and fed to the closed feedwater heater. Feedwater leaves the closed heater at 205°C, 10 MPa and condensate exits as saturated liquid at 2 MPa. The condensate is trapped into the open feedwater heater. Steam extracted from second turbine at 0.3 MPa is also fed into the open feedwater heater, which operates at 0.3 MPa. The steam exiting the open feedwater heater is saturated liquid at 0.3 MPa. The net power output (Wnet) of the cycle is 100 MW. There is no stray heat transfer from any component to its surroundings. If the working fluid experiences no irreversibilities as it passes through the turbines, pumps, steam generator, reheater and condenser, determine (a) the thermal efficiency (7th) of the cycle and (b) the mass flow rate (m) of steam entering the first turbine. Answers: (a) 44.6 %, (b) 75 kg/s Boiler, Reheater www 00 High-P Turbine Low-P Turbine Open FWH Pamp Condenser Pamp Trap +03