Performance Study of Refrigeration Units That Use the Refrigerant R-404A by Using Computer Simulation

Abstract

The performance parameters of vapor compression refrigeration units that used the refrigerant R-404A were studied by developing a computer simulation algorithm. The various performance parameters investigated per one kilowatt of refrigeration capacity, such as the mass flow rate, the compressor power consumption, the condenser heat rejection rate, the compressor exit temperature and the coefficient of performance. Two refrigeration cycles were tested under various evaporating and condensing temperatures: the standard cycle and the ideal cycle with superheating and sub-cooling. The results of the present work reveal that the compressor power variation over the evaporating temperature range from – 10 ℃ to 15 ℃ at Tc = 40 ℃ is decreased by 38.8% for standard cycle and by 43.8% for ideal cycle. The compressor power variation over the condensing temperature range from 30 ℃ to 50 ℃ at Te = 10 ℃ is increased by 122% for standard cycle and by 54.5% for ideal cycle. On the other hand, the COP for the ideal cycle with 5 ℃ superheating and sub-cooling is approximately 25% higher than that of the standard cycle at Te = 10 ℃ and Tc = 40 ℃ for the refrigerant R-404A.