Consider a reheat-regenerative vapor power cycle with two feedwater heaters, a closed feedwater heater and an open feedwater heater. Steam enters the first turbine at 8000 kPa and 480oC and expands to 700 kPa. The steam is reheated to 440oC before entering the second turbine, where it expands to the condenser pressure of 8 kPa. Steam is extracted from the first turbine at 2000 kPa and fed to the closed feedwater heater. The feedwater leaves the closed heater at 205oC and 8000 kPa and enters the boiler to complete the cycle. The condensate from the closed feedwater heater is throttled into the open feedwater heater. Steam extracted from the second turbine at 300 kPa is also fed into the open feedwater heater, which operates at 300 kPa. The stream exiting the open feedwater heater is saturated liquid at 300 kPa. The net power output of the cycle is 100 MW. If the working fluid experiences no irreversibilities as it passes through the turbines and pumps, determine:
(a) mass flowrate of the fluid entering the boiler in kg/h
(b) the heat transfer rate in the boiler in kJ/kg
(c) thermal efficiency of the power plant
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- Steam in a reheat Rankine cycle enters the first-stage turbine at 8 MPa and 450°C. The steam leaves this first turbine at 800 kPa as a saturated vapor. The steam is then reheated isobarically back to 450°C before entering the second-stage turbine. At the exit of this second turbine, the steam is at 10 kPa and 50°C. The net power output of this cycle is 20 MW, and the water leaves the condenser as a saturated liquid. You may assume the pump functions isentropically and that there are no pressure losses in the condenser and boiler. Determine C. d. e. MW. Draw this cycle on a T-s diagram. Calculate the isentropic efficiencies of the first- and second-stage turbines. Calculate the thermal efficiency of the cycle. Calculate the mass flow rate of steam, in kg/h. Calculate the rate of heat transfer from the water as it passes through the condenser, inarrow_forwardAn Ideal cogeneration steam plant is to generate power and 9400 kJ/s of process heat. Steam enters the turbine from the boller at 7 MPa and 500°C. One-fourth of the steam is extracted from the turbine at 600 kPa pressure for process heating. The remainder of the steam continues to expand and exhausts to the condenser at 10 kPa. The steam extracted for the process heater is condensed in the heater and mixed with the feedwater at 600 kPa. The mixture is pumped to the boller pressure of 7 MPa. 5 Boiler Pump II process Process heater 1-Ⓡ Turbine Condenser Pump I - (8) Determine the mass flow rate of steam that must be supplied by the boller. Use steam tables. The mass flow rate of steam that must be supplied by the boller is kg/s.arrow_forwardRequired information NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Consider a steam power plant that operates on a reheat Rankine cycle and has a net power output of 80 MW. Steam enters the high-pressure turbine at 10 MPa and 500°C and the low-pressure turbine at 1 MPa and 500°C. Steam leaves the condenser as a saturated liquid at a pressure of 10 kPa. The isentropic efficiency of the turbine is 72 percent and that of the pump is 95 percent. Determine the quality (or temperature, if superheated) of the steam at the turbine exit. Use steam tables. (You must provide an answer before moving on to the next part.) The temperature of the steam at the turbine exit is °C.arrow_forward
- An ideal Rankine cycle with one stage of reheat utilizes steam as working medium. Boiler pressure is 4 MPa, the boiler exit temperature is 400°C, and the condenser pressure is 10 kPa. The reheat takes place at 0.4 MPa and the steam leaves the reheater at 400°C. (Enthalpies are in KJ/kg.). Determine the thermal efficiency of the cycle. Determine also the thermal efficiency if there is no reheater. The quality at the exhaust of the low pressure turbine is: Select one: O a. 13% O b. 97% O c. 3% O d. 87%arrow_forwardConsider an ideal steam regenerative Rankine cycle with two feedwater heaters, one closed and one open. Steam enters the turbine at 10 MPa and 500 C and exhausts to the condenser at 10 kPa. Steam is extracted from the turbine at 0.7 MPa for the closed feedwater heater and 0.3 MPa for the open one. The extracted steam leaves the closed feedwater heater and is subsequently throttled to the open feedwater heater. Show the cycle on a T-s diagram with respect to saturation lines, and using only the data presented in the data tables given below determine a) the fraction for steam leaving the boiler that is extracted at 0.3 MPa z=0.1425 b) the fraction of steam leaving the boiler that is extracted at 0.7 MPa y=0.06213 c) the heat transfer from the condenser per unit mass leaving the boiler q_out=1509 kJ/kg d) the heat transfer to the boiler per unit mass leaving the boiler qin=2677 kJ/kg e) the mass flow rate of steam through the boiler for a net power output of 250 MW m'=214.1 kg/s f) the…arrow_forward
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