An ideal ammonia (R – 717) vapor-compression refrigeration cycle has an evaporator temperature of –20 C and a condenser pressure of 12 bar. Saturated vapor enters the compressor, and saturated liquid exits the condenser. The mass flow rate of the refrigerant is 3 kg/min. Determine the coefficient of performance.

In a vapor-compression refrigeration cycle, 9 kg/min of ammonia exits the evaporator as saturated vapor at-12°C. The refrigerant enters the condenser at 16 bar and 140C, and saturated liquid exits at 16 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. Determine the refrigerating capacity, in kW. kW %3D Determine the power input to the compressor, in kW. kW %3D

Determine the cooling capacity and the coefficient of performance of the air conditioning system?

13. A plant using R-134a is used to chill water for warship systems. The condenser is also cooled by water. Assume no undercooling in the condenser. The following data is to be used: 50L/s Water flowrate through evaporator Water inlet temperature to evaporator Water outlet temperature from evaporator -10°C 20°C 140L/s 350kPa 1100kPa Water flowrate through condenser Compressor suction pressure Compressor discharge pressure Compressor suction temperature Compressor discharge temperature Specific heat capacity of water Calculate: -10°℃ 60°C 4.2kJ/kgK a. Coefficient of Performance b. refrigerant cooling load c. refrigerant mass flowrate d. compressor power e. heat removed in condenser f. temperature change in condenser cooling water