A food storage locker requires a refrigeration system of 50 kW capacity at an evaporator temperature...

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A food storage locker requires a refrigeration system of 50 kW capacity at an evaporator temperature of -10°C and a condenser temperature of 35°C. The refrigerant used is ammonia which is subcooled by 5°C before entering the expansion valve and the vapor is dry saturated before leaving the evaporator. The two-cylinder compressor with stroke equal to 1.2 times the bore operates at 1000 rev/min. Determine: #al a. b. C. d. e. The coefficient of performance The mass of refrigerant to be circulated per minute, The power required The heat removed through condenser, and The cylinder dimension by using the following equation: II Compressor displacement: x d² xl x N xn 4 Where, d is the diameter, L is the stroke, N is rev/min and n is the number of cylinders. The volumetric efficiency of the compressor is 80%. [14 M] Use the ammonia table below for calculation: Enthalpy, kJ/kg Saturation temperature, °℃ - 10 35 Pressure, bar 2.91 13.5 Liquid Vapour 154 366 1450 1489 Entropy, kJ/kg K Liquid Vapour 5.75 0.83 1.56 5.21 Specific volume, m³/kg Liquid Vapour 1.7 0.42 0.096 Specific heat, kJ/kg K Liquid Vapour -- 4.56 2.49 2.90 A food storage locker requires a refrigeration system of 50 kW capacity at an evaporator temperature of -10°C and a condenser temperature of 35°C. The refrigerant used is ammonia which is subcooled by 5°C before entering the expansion valve and the vapor is dry saturated before leaving the evaporator. The two-cylinder compressor with stroke equal to 1.2 times the bore operates at 1000 rev/min. Determine: #al a. b. C. d. e. The coefficient of performance The mass of refrigerant to be circulated per minute, The power required The heat removed through condenser, and The cylinder dimension by using the following equation: II Compressor displacement: x d² xl x N xn 4 Where, d is the diameter, L is the stroke, N is rev/min and n is the number of cylinders. The volumetric efficiency of the compressor is 80%. [14 M] Use the ammonia table below for calculation: Enthalpy, kJ/kg Saturation temperature, °℃ - 10 35 Pressure, bar 2.91 13.5 Liquid Vapour 154 366 1450 1489 Entropy, kJ/kg K Liquid Vapour 5.75 0.83 1.56 5.21 Specific volume, m³/kg Liquid Vapour 1.7 0.42 0.096 Specific heat, kJ/kg K Liquid Vapour -- 4.56 2.49 2.90

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a Coefficient of performance COP Heat removed from evaporator Work by compressor Qeva W Heat ... View the full answer