Vapor-Compression Power and Refrigeration Cycles

An actual vapor compression refrigeration cycle operates at steady state with R-134a as the working fluid. The evaporator pressure is 120 kPa and the condenser pressure is 600 kPa. The mass flow rate of refrigerant is 0.1 kg/sec. The efficiency of the compressor is 85%. Determine (a) the compressor power,... 

R-134a enters the compressor of a steady-flow vapor compression refrigeration cycle as superheated vapor at 0.14 MPa and — 10°C at a rate of 0.04 kg/sec, and it leaves at 0.7 MPa and 50°C. The refrigerant is cooled in the condenser to 24°C and saturated liquid. Determine (a) the compressor power required, (b) the rate of heat absorbed from the refrigerated space, (c) the compressor efficiency, and (d) the COP. 

Refrigeration systems are important in industrial and home use when temperatures less than the ambient environment are required. Of the several types of refrigeration systems, the most widely used is the vapor-compression refrigeration cycle. It is essentially a Rankine cycle operated in reverse, where heat is absorbed from a cold reservoir and rejected to a hot reservoir. Due to the constraints of the second law, this process can be accomplished only with a concomitant consumption of power. 

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