A freezer is designed, based on vapor-compression refrigeration cycle. The designed conditions are: R-134a as refrigerant,...
(12 points) A refrigerator using refrigerant-134a as the working fluid operates on the vapor compression cycle. The cycle operates between 200 kPa and 1.2 MPa. The refrigerant flows through the cycle at a rate of 0.019 kg/s. The (actual) refrigerator has a compressor with an isentropic efficiency of 85%. The refrigerant enters the compressor slightly superheated by 56 C hint add this to the saturation temperature). The refrigerant leaves the condenser slightly subcooled by 1.9°C. What is the rate of...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34 °C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34 °C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat...
In a vapor-compression refrigeration heat pump cycle with Refrigerant 134a as the working fluid provides heating at a rate of 15 kW to maintain a building at 20 °C year-round. During the heating mode in the winter, the outside temperature is 5 °C. It is also used for cooling in the summer when outside temperature is 34°C. Saturated vapor at 2.4 bar leaves the evaporator and superheated vapor at 8 bar leaves the compressor. There is no significant heat transfer...
Tt (12 points) A refrigerator using refrigerant-134a as the working fluid operates on the vapor compression cycle. The cycle operates between 200 kPa and 1.2 MPa. The refrigerant flows through the cycle at a rate of 0.015 kg/s. The actual) refrigerator has a compressor with an isentropic efficiency of 82%. The refrigerant enters the compressor slightly superheated by 6.2°C (hint: add this to the saturation temperature). The refrigerant leaves the condenser slightly subcooled by 1.8°C. What is the rate of...
A two-stage compression refrigeration system with an adiabatic liquid-vapor separation unit uses refrigerant-134a as working fluid. The system operates the evaporator at 0.4 MPa, the condenser at 1.6 MPa, and the separator at 0.8 MPa. The compressors use 25 kW of power. Given that the refrigerant is saturated liquid at the inlet of each expansion valve and saturated vapor at the inlet of each compressor, and the compressors are isentropic: (0) show the process on a T-s diagram; ) calculate...
The mass flow rate of R-134a in a vapor-compression refrigeration cycle is 6 kg/min. At the inlet of the compressor, R-134a is at -10°C, 150 kPa. The pressure at the compressor exit is 600 kPa. The compressor has an isentropic efficiency of 67%. The refrigerant leaves the condenser at 20°C. Neglect any pressure drops in the condenser, the evaporator, and pipes. Assume an adiabatic compressor. (a)draw the cycle and the T-s diagram of the cycle. Also find: (b)the coefficient of the performance...
An ideal vapor-compression refrigeration cycle that uses refrigerant R-134a as its working fluid maintains a condenser at 800 kPa and the evaporator at -12C. (a) Determine this system's COP and the amount of power required to service a 150kW cooling load. (b) Determine the P,T, h, S and exergy of R-134a at all four states of the entire cycle. Assume the ambient temperature to be 25C.
Thermodynamics. No interpolation needed. Problem #3. Refrigerant 134a is the working fluid for vapor-compression refrigeration cycle. The evaporator temperature is 8°C and the condenser pressure is 12 bar. Saturated vapor enters the compressor and superheated vapor enters the condenser at 60°C and exits the condenser as saturated liquid. For a refrigeration capacity of 8 tons or 2.816 x104 J/s determine the following: (1) The refrigerant mass flow rate in kg/s; (2) The compressor isentropic efficiency [Hint: Interpolation is required); (3)...
1. An industrial freezer uses a multi-stage vapor-compression cycle with R-134a as the working fluid. The evaporator operates at 140 kPa, the condenser at 1600 kPa, and the flash chamber 600 kPa. The refrigerant leaves the evaporator as a super-heated vapor at -15°C, and leaves the condenser as a sub-cooled liquid at 50°C. Both compressors used in the system have isentropic efficiencies of 85%. For a cooling load of 25 kW, (a) What is the mass flow rate of refrigerant...