【摘要】 为了解决制冷剂对环境污染的问题，本文对制冷剂R449A在低温冷藏制冷系统中直接替代R404A的性能进行了实验研究。结果表明：制冷剂R449A直接替代后的制冷系统与原R404A系统相比，吸排气压力平均低0.14 MPa，吸气温度平均低2.15℃，排气温度平均上升了8℃，输入功率平均减小15.13%，制冷量平均减小4.1%，性能系数平均提高7.3%，虽然替代后的系统排气温度有明显升高和压缩比增大，但均未超过压缩机运行限值，且替换后的系统还具有足够的制冷能力和较好的性能，研究证实新型制冷剂R449A可用作在冷藏条件下制冷系统R404A的直接替代制冷剂。更多还原

【Abstract】 In order to solve the problem of environmental pollution caused by refrigerant, the performance of refrigerant R449A directly replacing R404A in cryogenic refrigeration system is experimentally studied in this paper. The results show that, compared with the R404A system, the average suction and exhaust pressure of the refrigeration system directly replaced by refrigerant R449A is 0.14 MPa lower, the average suction temperature is 2.15 ℃ lower, the average exhaust temperature is 8 ℃ higher, the average input power is 15.13% lower, the average cooling capacity is 4.1% lower, and the average coefficient of performance is 7.3% higher. Although the exhaust temperature of the replaced system has increased, it does not exceed the operating limit of the compressor,and the replaced system had sufficient refrigeration capacity and good performance. It is confirmed that the new refrigerant R449A can be used as a direct substitute for the refrigeration system R404A under refrigeration conditions.更多还原