Reference no: EM13634043

Water is the working fluid in a regenerative Rankine cycle with one closed feedwater heater and one open feedwater heater. Steam enters the turbine at 1400 lbf/in.2 and 10008F and expands to 500 lbf/in.2, where some of the steam is extracted and diverted to the closed feedwater heater. Condensate exiting the closed feedwater heater as saturated liquid at 500 lbf/in.2 undergoes a throttling process to 120 lbf/in.2 as it passes through a trap into the open feedwater heater. The feedwater leaves the closed feedwater heater at 1400 lbf/in.2 and a temperature equal to the saturation temperature at 500 lbf/in.2 The remaining steam expands through the second-stage turbine to 120 lbf/in.2, where some of the steam is extracted and diverted to the open feedwater heater operating at 120 lbf/in.2 Saturated liquid exits the open feedwater heater at 120 lbf/in.2 The remaining steam expands through the third-stage turbine to the condenser pressure of 2 lbf/in.2 All processes of the working fluid in the turbine stages and pumps are internally reversible. Flow through the condenser, closed feedwater heater, open feedwater heater, and steam generator is at constant pressure. The net power output of the cycle is 1 3 109 Btu/h. 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.