Modify the ideal Rankine cycle of the mentioned problem to include one closed feedwater heater using extracted steam at Condensate exiting the heater as a saturated liquid at passes through a trap into the condenser. The feedwater leaves the heater at and a temperature equal to the saturation temperature at in. The mass flow rate of steam entering the first-stage turbine is the same as the steam flow rate in the mentioned problem. Reply to the same questions about the modified cycle as in the mentioned problem and discuss the results.
A power plant works on a regenerative vapor power cycle with one closed feedwater heater. Steam enters the first turbine stage at 120 bar, and expands to 10 bar, where some of the steam is extracted and diverted to a closed feedwater heater. Condensate exiting the feedwater heater as a saturated liquid at 10 bar passes through a trap into the condenser. The feedwater exits the heater at 120 bar with a temperature of . The condenser pressure is bar. For isentropic processes in each turbine stage and the pump, determine for the cycle (a) the thermal efficiency and (b) the mass flow rate into the first-stage turbine, in , if the net power developed is .
Modify the ideal Rankine cycle of the mentioned problem to include superheated vapor entering the first turbine stage at , , and one open feedwater heater operating at . The saturated liquid exits the open feedwater heater at . Find the modified cycle
(a) the net work, in per of steam entering the first turbine stage.
(b) the thermal efficiency.
(c) the heat transfer to cooling water passing through the condenser, in per of steam entering the first turbine stage.