feedwater heaters, a closed one and an open one. Steam enters the first-stage turbine at 12 MPa, 480°C, and expands to 2 MPa. Some steam is extracted at 2 MPa and fed to the closed feedwater heater. The remainder of the steam expands through a second-stage turbine to 0.3 MPa, where an additional amount is extracted and fed into the open feedwater heater operating at 0.3 MPa. The remaining steam expands through a third-stage turbine and exits at the condenser pressure of 6 kPa. Feedwater leaves the closed heater at 210°C, 12 MPa, and condensate exiting as saturated liquid at 2 MPa is trapped into the open feedwater heater. Saturated liquid at 0.3 MPa leaves the open feedwater heater. Assume all pumps and turbine stages operate isentropically. Determine for the cycle: a. The rate of heat transfer to the working fluid passing through the steam generator, in kJ per kg of steam entering the first-stage turbine. b. The thermal efficiency of the cycle. c. The rate of heat transfer from the working fluid passing through the condenser to the cooling water, in kJ per kg of steam entering the first stage turbine. 1. Consider a regenerative vapor compression power cycle shown below with two
temperature data are given at the principal states, and the net power developed by the gas turbine is 147 MW. Determine: a. The next power, in MW, developed for the power plant. b. The overall thermal efficiency of the power plant. the required makeup water for these conditions. 2. A combined gas turbine-vapor power plant operates as shown. Pressure and 3. A natural draft cooling tower is used to cool 110 kg/s of water from 42°C to 28°C. Atmospheric air enters the cooling tower at a dry bulb temperature of 37°C with a relative humidity of 30% and leaves saturated at 39°C. Makeup water is available at 24°C. Determine the mass flow rate of air entering the tower and the mass flow rate of