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
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
EBK THERMODYNAMICS: AN ENGINEERING APPR
- Superheated water vapor enters the turbine at 5Mpa and 4000C. The water leaves the condenser as saturated liquid at a pressure of 30kPa, and the turbine efficiency is 91%. The net power output of the cycle is 100MW. Determine the thermal efficiency.arrow_forwardSteam is generated at a pressure of 8MPa and leaves the steam generator at 450°C. After the expansion to 700 kPa, the steam undergoes reheat and expands again in a low-pressure turbine. the condenser pressure is 8kPa. The steam flows at the rate of 2.63 x 10 ^ 5 kg/h. If the power plant operates in a Rankine cycle, determine the net power generated and heat transfer in the condenser.arrow_forwardConsider a cogeneration power plant that is modified with reheat and that produces 3 MW of power and supplies 7 MW of process heat. Steam enters the high- pressure turbine at 8 MPa and 500°C and expands to a pressure of (1 MPa. At this pressure, part of the steam is extracted from the turbine and routed to the process heater, while the remainder is reheated to 500°C and expanded in the low-pressure turbine to the condenser pressure of 15 kPa. The condensate from the condenser is pumped to 1 MPa and is mixed with the extracted steam, which leaves the process heater as a compressed liquid at 120°C. The mixture is then pumped to the boiler pressure. Assuming the turbine to be isentropic, show the cycle on a T-s diagram with respect to saturation lines, and disregarding pump work, determine (a) the rate of heat input in the boiler and (b) the fraction of steam extracted for process heating. bur Pamp 11 Posess 1-0 (2) Mong 1 hamber Harbie Condenser EST ATWarrow_forward
- In a Rankine cycle with reheating, the steam leaves the boiler at 2.5 MPa and 600 ºC and enters the high-pressure turbine where it expands to a pressure of 1 MPa to be then subjected to a reheating process from where it leaves at 1 MPa and 600 ° C. The steam at these conditions enters the low-pressure turbine and expands up to the condenser pressure of 50 kPa. The heat that is extracted in the condenser is 1500 kJ / s. If the adiabatic efficiency of the turbines and the pump is 95%, determine the total heat flow in kJ / s delivered to the boiler.arrow_forwardIn a Rankine cycle with reheating, the steam leaves the boiler at 2.5 MPa and 600 ºC and enters the high pressure turbine where it expands to a pressure of 1 MPa to be then subjected to a reheating process from where it leaves at 1 MPa and 600 ° C. The steam at these conditions enters the low pressure turbine and expands up to the condenser pressure of 50 kPa. The heat that is extracted in the condenser is 1500 kJ / s. If the adiabatic efficiency of the turbines and the pump is 95%, determine the total heat flow in kJ / s delivered to the boiler.arrow_forwardSteam enters the high-pressure turbine of a steam power plant that operates on the ideal reheat Rankine cycle at 800 psia and 900F and leaves as saturated vapor. Steam is then reheated to 800F before it expands to a pressure of 1 psia. Heat is transferred to the steam in the boiler at a rate of 6 * 104 Btu/s. Steam is cooled in the condenser by the cooling water from a nearby river, which enters the condenser at 45F. Show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the pressure at which reheating takes place, (b) the net power output and thermal efficiency, and (c) the minimum mass flow rate of the cooling water required.arrow_forward
- 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_forwardA power plant is to be operated on a Rankine Cycle with superheated steam exiting the boiler at 4 MPa and 500°C. The condenser pressure is 20 kPa. Compute the specific steam consumption of the cycle in kg/kWharrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY