An ideal cogeneration steam plant is to generate power and 8600 kJ/s of process heat. Steam enters the turbine from the boiler 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 boiler pressure of 7 MPa. Show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the mass flow rate of steam that must be supplied by the boiler, (b) the net power produced by the plant, and (c) the utilization factor.
FIGURE P10–76
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- A steam turbine cycle running on a Rankin cycle between a condenser pressure of 10 kPa and a boiler pressure of 20 MPa, the steam enters the high pressure turbine at a temperature of 600 ° C. The average turbine expands to 800 kPa and then enters the boiler again to be reheated to 500 ° C. The steam leaves the boiler to a low pressure turbine, where it expands to the condenser pressure. If the expansion and compression in the turbine and the pump is isotropic, and the addition of heat is constant pressure, find the efficiency of the cycle. Note point # 1 at the vapor exit region of the condenserarrow_forwardSteam is generated in the boiler of a cogeneration plant at 9 MPa and 450C at a steady rate of 5 kg/s. In normal operation, steam expands in a turbine to a pressure of 0.5 MPa and is then routed to the process heater, where it supplies the process heat. Steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. In this mode, no steam passes through the condenser, which operates at 20 kPa. Draw the schematic and T-S diagrams. Label the points by setting point 1 at the condenser outlet, point 2 at the 1st pump (after the condenser) outlet, point 3 at the process heater outlet, point 4 at the 2nd pump (after the process heater) outlet, point 5 at the boiler inlet, point 6 at the boiler outlet, point 7 at the process heater inlet, and point 8 at the condenser inlet. Use 2 decimal places for the enthalpy and other energies in solving and for the final answers. For the steam quality (x) and entropy (s), use 4 decimal places in solving. For the specific…arrow_forwardSteam is generated in the boiler of a cogeneration plant at 9 MPa and 450C at a steady rate of 5 kg/s. In normal operation, steam expands in a turbine to a pressure of 0.5 MPa and is then routed to the process heater, where it supplies the process heat. Steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. In this mode, no steam passes through the condenser, which operates at 20 kPa. Draw the schematic and T-S diagrams. Label the points by setting point 1 at the condenser outlet, point 2 at the 1st pump (after the condenser) outlet, point 3 at the process heater outlet, point 4 at the 2nd pump (after the process heater) outlet, point 5 at the boiler inlet, point 6 at the boiler outlet, point 7 at the process heater inlet, and point 8 at the condenser inlet. Use 2 decimal places for the enthalpy and other energies in solving and for the final answers. For the steam quality (x) and entropy (s), use 4 decimal places in solving. For the specific…arrow_forward
- Consider a 150-MW steam power plant that operates on a simple Rankine cycle. Steam enters the turbine at 7 MPa and 500°C and is cooled in the condenser at 10 kPa. Calculate the thermal efficiency of the plant. Assume an isentropic efficiency of 87% for both the turbine and the pumparrow_forwardSteam is generated in the boiler of a cogeneration plant at 8 MPa and 400C at a steady rate of 5 kg/s. In normal operation, steam expands in a turbine to a pressure of 0.4 MPa and is then routed to the process heater, where it supplies the process heat. Steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. In this mode, no steam passes through the condenser, which operates at 15 kPa. Draw the schematic and T-S diagrams. Label the points by setting point 1 at the condenser outlet, point 2 at the 1st pump (after the condenser) outlet, point 3 at the process heater outlet, point 4 at the 2nd pump (after the process heater) outlet, point 5 at the boiler inlet (after mixing chamber), point 6 at the boiler outlet, point 7 at the process heater inlet (no throttle valve), and point 8 at the condenser inlet. Use 2 decimal places for the enthalpy and other energies in solving and for the final answers. For the steam quality (x) and entropy (s), use 4 decimal…arrow_forwardConsider a 150-MW steam power plant that operates on a simple Rankine cycle. Steam enters the turbine at 7 MPa and 500°C and is cooled in the condenser at 10 kPa. Calculate the volume flow rate of sea water (S.G. = 1.05) used in the condenser, if the allowable temperature rise is 5°C. Assume an isentropic efficiency of 87% for both the turbine and the pump.arrow_forward
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