- Water Is The Working Fluid In A Reheat Regenerative Rankine Cycle With One Closed Feedwater Heater And One Open Feedwate 1 (113.51 KiB) Viewed 32 times
(a) the mass flow rate of steam entering the first stage of the
turbine, in lb/h.
(b) the rate of exergy input, in Btu/h, to the working fluid
passing through the steam generator.
(c) the magnitude of the exergy output, in Btu/h, of the net
power output.
(d) the magnitude of the exergy loss in the condenser, in
Btu/h.
(e) the exergy destroyed in the tubine, in Btu/h.
(f) the exergy destroyed in the open feedwater heater, in
Btu/h.
Water is the working fluid in a reheat-regenerative Rankinę cycle with one closed feedwater heater and one open feedwater heater. Steam enters the turbine at 1400 lbf/in.- and 1000°F and expands to 500 lbf/in., where some of the steam is extracted and diverted to the closed feedwater heater. Condensatę exiting the closed feedwater heater as saturated liquid at 500 lbf/in- undergoes a throttling process to 120 lbf/in.- as it passes through a trap into the open feedwater heater. 2 The feedwater leaves the closed feedwater heater at 1400 lbf/in. and a temperature equal to the saturation temperature at 500 lbf/in. The remaining steam is reheated to 900°F before entering the second-stage turbine, where it expands to 120 lbf/in. Some of the steam is extracted and diverted to the open feedwater heater operating at 120 lbf/in.- 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. The turbine stages and the pumps each operate adiabatically with isentropic efficiencies of 85%. Flow through the condenser, closed feedwater heater, open feedwater heater, steam generator, and reheater is at constant pressure. The net power output of the cycle is 1.5 x 10 Btu/h. Let To = 60°F, po = 14.7 lbf/in.- The table below provides steady-state operating data for the cycle. State h (Btu/lb) s (Btu/lb.OR) s 1 1493 1.609 2 1375 1.627 3 1375 1.627 4 1466 1.698 5 1315 1.725 6 1049 1.805 7 94.12 0.1751 8 94.54 0.1758 9 312.5 0.4917 10 317.5 0.4979 11 449.6 0.6491 12 449.6 0.6491 13 449.6 0.663