Water is the working fluid in a regenerative Rankine cycle with one closed feed water heater and one open feed water heater. Steam enters the turbine at 1400 psi and 1000 F and expands to 500 psi, where some of the steam is extracted and diverted to the closed feed water heater. Condensate exiting the closed feed water heater as saturated liquid at 500 psi undergoes a throttling process to 120 psi as it passes through a trap into the open feed water heater. The feed water leaves the closed feed water heater at 1400 psi and a temperature equal to the saturation temperature at 500 psi. The remaining steam expands through the second-stage turbine to 120 psi, where some of the steam is extracted and diverted to the open feed water heater operating at 120 psi. Saturated liquid exits the open feed water heater at 120 psi. The remaining steam expands through the third-stage turbine to the condenser pressure of 2 psi. The turbine stages and the pumps each operate adiabatically with isentropic efficiencies of 85%. Flow through the condenser, closed feed water heater, open feed water heater, and steam generator is at constant pressure. The net power output of the cycle is 1e9 Btu/hr. Determine for the cycle:
a) The mass flow rate of steam entering the first stage of the turbine in lb/h.
b) The rate of heat transfer, in Btu/h, to the working fluid passing through the steam generator
c) The thermal efficiency