A heat pump cycle using water as the working fluid consists of a compressor, a condenser, an expansion valve, and an evaporator. Saturated vapor with mass flow rate of 1 kg/s at 0.5 MPa (state 1) enters the condenser and leaves it as saturated liquid at the same pressure (state 2). The pressure in the evaporator is 0.01 MPa. The condenser and the evaporator processes are isobaric. The compressor is adiabatic and reversible. The valve is adiabatic. A. List all the known information and assumptions. B. Determine the heat output of the condenser (QH) C. Determine the heat input of the evaporator(Qc) D. Determine the coefficient of performance of the heat pump. E. Determine the coefficient of performance of a Carnot heat pump running between the same

A heat pump cycle using water as the working fluid consists of a compressor, a condenser, an expansion valve, and an evaporator. Saturated vapor with mass flow rate of 1 kg/s at 0.5 MPa (state 1) enters the condenser and leaves it as saturated liquid at the same pressure (state 2). The pressure in the evaporator is 0.01 MPa. The condenser and the evaporator processes are isobaric. The compressor is adiabatic and reversible. The valve is adiabatic. A. List all the known information and assumptions. B. Determine the heat output of the condenser (QH) C. Determine the heat input of the evaporator(Qc) D. Determine the coefficient of performance of the heat pump. E. Determine the coefficient of performance of a Carnot heat pump running between the same

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

Chapter45: Domestic Refrigerators And Freezers

Section: Chapter Questions

Problem 2RQ: The operating condition for the single compressor in a household refrigerator is the lowest box...

See similar textbooks

Similar questions

Refrigerators currently being manufactured in the United States are using______as their refrigerant.
Referring to Problem 1.74, how many kilograms of ice can a 3-ton refrigeration unit produce in a 24-h period? The heat of fusion of water is 330 kJ/kg.
The operating condition for the single compressor in a household refrigerator is the lowest box temperature, which is typically A. 0F B. -20F C. 20F D. 40F
Condensers in these refrigerators are all_______cooled.
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
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.
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.
Air enters the compressor of an ideal gas refrigeration cycle at 12°C and 50 kPa and the turbine at 47°C and 250 kPa. The mass flow rate of air through the cycle is 0.08 kg/s. Assuming variable specific heats for air, determine (a) the rate of refrigeration, (b) the net power input, and (c) the coefficient of performance.
A simple vapor compression cycle develops 15 tons of refrigeration using ammonia as refrigerant and operating at condensing temperature of 24 C and evaporating temperature of -18C and assuming compression are isentropic and that the gas leaving the condenser is saturated, find the power per ton. Properties of Ammonia: h1=hf = 312.87 kJ/kg h2= 1665 kJ/kg At -18C hg = 1439.94 kJ/kg
The COP of vapor-compression refrigeration cycles improves when the refrigerant is subcooled before it enters the throttling valve. Can the refrigerant be subcooled indefinitely to maximize this effect, or is there a lower limit? Explain.
Refrigerant 134a is the working fluid in a vapor- compression heat pump that provides 35 kW to heat a dwelling on a day when the outside temperature is below freezing. Saturated vapor enters the compressor at 1.6 bar, and saturated liquid exits the condenser, which operates at 8 bar. Determine, for isentropic compression: a- the refrigerant mass flow rate, in kg/s. b- the compressor power,in kW. c- The coefficient of performance. Recalculate the quantities in parts (b) and (c) for an isentropic compressor efficiency of 75%.
Refrigerant 134a is the working fluid in a vapor compression heat pump that provides 35 kW heat to a dwelling. Saturated vapor enters the compressor at 1.6 bar, and saturated liquid exits the condenser, which operates at 8 bars. Isentropic efficiency of the compressor is 75%. The pressure drops across the condenser and evaporator can be neglected. Kinetic and potential energy changes are negligible. a) Determine the compressor power, in kW b) Determine the coefficient of performance (COP) c) Draw the processes in a T-s diagram