A steam power plant operates on a thermodynamic cycle in which water circulates through a boiler, turbine, condenser, pump, and back to the boiler. For each kilogram of steam (water) flowing through the cycle, the cycle receives 2100 kJ of heat in the boiler, rejects 1100 kJ of heat to the environment in the condenser, and receives 10 kJ of work in the cycle for stage one pump and another 10 kJ of work in the cycle for second stage one

A steam power plant operates on a thermodynamic cycle in which water circulates through a boiler, turbine, condenser, pump, and back to the boiler. For each kilogram of steam (water) flowing through the cycle, the cycle receives 2100 kJ of heat in the boiler, rejects 1100 kJ of heat to the environment in the condenser, and receives 10 kJ of work in the cycle for stage one pump and another 10 kJ of work in the cycle for second stage one

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.22 MPa and 27 C at a rate of 0.07 kg/s, and it leaves at 1.2 MPa and 73°C. The refrigerant is cooled in the condenser to 44°C and 1.16 MPa, and t is throttied to 0.21 MPa. Disregarding any heat transfer and pressure drops in the connecting lines between the components, show the cycle on a T-s diagram with respect to saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the power input to the compressor, (b) the isentropic efficiency of the compressor, and (c) the COP of the refrigerator.
A binary vapor power cycle consists of two ideal Rankine cycles with steam and Refrigerant 134a as the working fluids. The mass flow rate of steam is 2 kg/s. In the steam cycle, superheated vapor enters the turbine at 8 MPa, 560°C, and saturated liquid exits the condenser at 50 kPa. In the interconnecting heat exchanger, energy rejected by heat transfer from the steam cycle is provided to the Refrigerant 134a cycle. The heat exchanger experiences no stray heat transfer with its surroundings. Superheated Refrigerant 134a leaves the heat exchanger at 600 kPa, 30°C, which enters the Refrigerant 134a turbine. Saturated liquid leaves the Refrigerant 134a condenser at 100 kPa.Determine:(a) the net power developed by the binary cycle, in kW.(b) the rate of heat addition to the binary cycle, in kW.(c) the percent thermal efficiency of the binary cycle.(d) the rate of entropy production in the interconnecting heat exchanger, in kW/K.
A 1000-MW supercritical double-reheat steam power plant operates withthe main (live) steam condition of 250 bars and 560°C and the condenserpressure of 0.04 bar. The steam is reheated first at 30 bars to 560°C andthen at 4 bars to 560°C. The turbine efficiency is 0.92. The feed pumpwork may be ignored. Calculate: (a) the plant net specific work, (b) the plant thermal efficiency, (c) the plant steam mass flow rate, and (d) the plant heat rate.
A binary vapor power cycle consists of two ideal Rankine cycles with steam and Refrigerant 134a as the working fluids. The mass flow rate of steam is 2 kg/s. In the steam cycle, superheated vapor enters the turbine at 8 MPa, 600C, and saturated liquid exits the condenser at 250 kPa. In the interconnecting heat exchanger, energy rejected by heat transfer from the steam cycle is provided to the Refrigerant 134a cycle. The heat exchanger experiences no stray heat transfer with its surroundings. Superheated Refrigerant 134a leaves the heat exchanger at 600 kPa, 30C, which enters the Refrigerant 134a turbine. Saturated liquid leaves the Refrigerant 134a condenser at 100 kPa. Determine (a) The net power developed by the binary cycle, in kW. (b) The rate of heat addition to the binary cycle, in kW. (c) The thermal efficiency of the binary cycle.
Consider a water-ammonia binary vapor cycle consisting. In the steam cycle, superheated vapor enters the turbine at 7 MPa, 450C, and saturated liquid exits the condenser at 55C. The heat rejected from the steam cycle is provided to the ammonia cycle, producing saturated vapor at 45C, which enters the ammonia turbine. Saturated liquid leaves the ammonia condenser at 1 MPa. For a net power output of 24 MW from the binary cycle, determine (a) the mass flow rates for the steam and ammonia cycles, respectively, in kg/s, (b) the power output of the steam and ammonia turbines, respectively, in MW. (c) the rate of heat input to the ammonia cycle, in MW, (d) the rate of heat addition to the binary cycle, in MW, and (e) the thermal efficiency of the binary vapor cycle.
A two -stage staged refrigeration cycle works at a lowest pressure of 0.8 bar and a highest of 8 bar. Each stage works as an ideal vapor compression system with R-134a as the working fluid. The release of heat from the lower cycle to the upper cycle takes place in an adiabatic heat exchanger of opposite flow where both flows in at a pressure of 3 bar. If the refrigrant mass flow rate in the upper cycle is 0.075 kg/s, calculate: a). Refrigerant mass flow rate at the bottom cycle b). Heat absorption power of the cooled room, in kW c). Supply power to compressor d). COP refrigerator Note: siklus is cycle and below the environment the purple one is QH,(the image was blur) so i explain on the note,thx
Consider a water-ammonia binary vapor cycle consisting. In the steam cycle,superheated vapor enters the turbine at 7 MPa, 450oC, and saturated liquid exits thecondenser at 55oC. The heat rejected from the steam cycle is provided to the ammoniacycle, producing saturated vapor at 45oC, which enters the ammonia turbine.Saturated liquid leaves the ammonia condenser at 1 MPa. For a net power output of24 MW from the binary cycle, determine (c) the rate of heat input to the ammoniacycle, in MW, (d) the rate of heat addition to the binary cycle, in MW, and (e) thethermal efficiency of the binary vapor cycle.
Refrigerator 1 simulates an ideal refrigerator and therefore operates on a Carnot cycle using R-134a as the refrigerant at a flow rate of 1.4 kg/sec. The condensing and evaporating temperatures are 30 °C and -10 °C, respectively. To assess the performance of Refrigerator 1, you must submit the report. of the project with the following information: d) The work generated by the turbine; e) The condenser heat rejection rate (Q H); f) The coefficient of performance of the cycle.
The figure below shows a vapor power cycle that provides process heat and produces power. The steam generator produces vapor at 500 lbf/in.2, 800°F, at a rate of 8 x 104 lb/h. Eighty-eight percent of the steam expands through the turbine to 10 lbf/in.2 and the remainder is directed to the heat exchanger. Saturated liquid exits the heat exchanger at 500 lbf/in.2 and passes through a trap before entering the condenser at 10 lbf/in.2Saturated liquid exits the condenser at 10 lbf/in.2 and is pumped to 500 lbf/in.2 before entering the steam generator. The turbine and pump have isentropic efficiencies of 85% and 89%, respectively. For the process heat exchanger, assume the temperature at which heat transfer occurs is 465°F. Let T0 = 60°F, p0 = 14.7 lbf/in.2 Determine:(a) the magnitude of the process heat production rate, in Btu/h.(b) the magnitude of the rate of exergy output, in Btu/h, as net work.(c) the rate of exergy transfer, in Btu/h, to the working fluid passing through the steam…
Refrigerant 134a enters the compressor of a refrigerator as superheated vapor at 0.20 MPa and -5 ° C at a rate of 0.7 kg / s, and exits at 1.2 MPa and 70 ° C. The refrigerant is cooled in the condenser to 44 ° C and 1.15 ° C. MPa, and throttles at 0.2 MPa. Neglecting any heat transfer and any pressure drop in the connecting lines between the components, show the cycle on a Ts diagram with respect to the saturation lines, and determine (a) the rate of heat removal from the refrigerated space and the inlet power to the compressor, b) the isentropic efficiency of the compressor, c) the COP of the refrigerator, d) show the Ts and Ph diagrams with all points
An ideal vapor-compression refrigeration cycle employs refrigerant 134a as the working fluid and operates at a steady state. At the compressor inlet, saturated vapor enters a -20 degrees celcius, and the saturated liquid leaves the condenser at 42 degrees celcius. The mass flow rate of the refrigerant is 0.5 kg/s. Determine: a) The rate of heat rejection from the condenser in kW b) The compressor power in kW c) The coefficient of performance
A 286-MW steam power plant operates on the Rankine cycle but with turbine and pump efficiencies of 90%. The steam enters the turbine at 10,000 kPa and 550°C. It discharges to the condenser at 50 kPa. Determine the mass fraction of steam that condenses at the turbine exit in percent.