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 ...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.展开更多
A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system. The model is then used to de...A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system. The model is then used to determine the refrigerant charge in vapor compression units. The model is used for a sensitivity analysis to determine the effect that yaring design parameters on the refrigerant charge. The model is also used to evaluate the effect of refrigerant charge and the thermal physical properties on the refrigeration cycle. The predicted value of the refrigerant charge and experimental data agree well.The model and the method presented in this paper could be used to design vapour compression units such as domestic refrigerators and air conditioners.展开更多
文摘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.
文摘A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system. The model is then used to determine the refrigerant charge in vapor compression units. The model is used for a sensitivity analysis to determine the effect that yaring design parameters on the refrigerant charge. The model is also used to evaluate the effect of refrigerant charge and the thermal physical properties on the refrigeration cycle. The predicted value of the refrigerant charge and experimental data agree well.The model and the method presented in this paper could be used to design vapour compression units such as domestic refrigerators and air conditioners.
