Warm region H The compressor of the vapor-compression refrigerator takes in 0.2 kg/s of R134a as...
3) A vapor-compression refrigerator uses refrigerant-134a. Superheated vapor enters the compressor at 100 kPa and -20° C, and exits at 1 MPa and 60° C. The refrigerant is cooled to 35° C in the condenser and then expands back to 100 kPa through an expansion valve. Neglect pressure losses within the condenser and evaporator. The refrigerant flow rate is 0.10 kg/s. Calculate the following a) the rate of heat removal from the cooled space, in kw, b) the rate of...
(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...
1. R134a in a vapor compression heat pump generates 35 kW of heat to a cold room. Saturated vapor enters the compressor at 1.6 bar and saturated liquid exits the condenser at 8 bar. Assuming 75% isentropic efficiency for the compressor, determine: a) Mass flow rate (kg/s) b) Compressor power (kW) c) Heat transfer from the outside d) Coefficient of performance
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...
The power input to the compressor of an ammonia vapor compression plant is 8.2 kW. The mechanical efficiency is 85%. The ammonia is dry saturated vapor at -5oC at inlet to the compressor. After compression, the vapor is at 1000 kPa. The compressor has an isentropic efficiency of 90%. The condenser produces saturated liquid. Calculate the coefficient of performance for the refrigerator and for the heat pump for this plant.
Problem-3 (200) In a vapor-compression refrigeration cycle, R134a exits the evaporator as saturated vapor at -32°C. The refrigerant enters the condenser at 14 bar and 170°C, and saturated liquid exits at 14 bar. There is no significant heat transfer between the compressor and its surroundings, and the refrigerant passes through the evaporator with a negligible change in pressure. If the mass flow rate is 2.987 kg/s, determine (a) Refrigeration capacity in KW (100) (b) The power input to the compressor,...
1. Saturated R134a vapor enters the uninsulated compressor of a home central air- conditioning system at 4 °C. The flow rate of R134a through the compressor is 0.1 kg/s, and the electrical power input is 5 kW. The exit state is 65 °C with 1000 kPa. Any heat transfer from the compressor is to the ambient environment at 27 °C. a) Determine the rate of entropy production for the process in kW/K. b) If the change in enthalpy for the...
In a simple vapor compression refrigeration cycle: - Ammonia exits the evaporator as saturated· vapor at -22°C (State 1 ) .. - Ammonia enters the condenser at 16 Bar and 160°C (State 2; h2 = 1798.45 kJ/kg) - Ammonia exits the condenser as saturated l1quid at 16 Bar (State 3; h3 = 376.46 kJ/kg) - The refrigeration capacity is 150 kW. Draw the system schematic and the T-s diagram and determine: i) the mass flow rate· of refrigerant, ii) the...
Condenser Compressor An ideal vapor-compression refrigeration cycle is modified to include a counter-flow heat exchanger as shown. Refrigerant 134a leaves the evaporator as saturated vapor at 0.10 MPa and is heated at constant pressure to 20°C before entering the compressor. Following isentropic compression to 1.4 MPa, the refrigerant passes through the condenser and exits at 45°C and 1.4 MPa. The liquid then passes through the heat exchanger and enters the expansion valve at 1.4 MPa. The mass flow rate of...
Refrigeration Question 1 a) A refrigerant R134a refrigerator is to maintain the refrigerated space at -100C. Would you recommended an evaporator pressure of 1.6 bar or 2 bar for this system? Why? -la An automotive Air conditioner using refrigerant R134a as the working fluid and operating on ideal vapor compression refrigerant cycle is to maintain a space at 24°C while operating its condenser at 1000 kPa. Determine the COP of the system when a temperature difference of 14°C is allowed...