R134a和R407c对热泵空调系统性能的影响

Performance Research of Heat Pump System Employing R134a and R407c

为了比较R134a和R407c两种制冷剂对热泵空调系统性能的影响,对热泵空调系统分别充注以上两种制冷剂,在焓差实验室分别测试它们在蒸发温度(-25~15℃)、冷凝温度(30~70℃)下的排气温度、制冷量、制热量、输入功率和COP。通过试验结果分析得出:蒸发温度对制冷量和制热量的影响大,冷凝温度对压缩机输入功率影响大;空调冬季供热时,R407c的平均COP比R134a高27.6%;空调夏季制冷时,R134a的平均COP比R407c高4.3%。因此,空调系统在低温环境运行时应选择R407c,而空调系统在高温环境运行时则选择R134a。

For evaluation of the performance of a heat pump air conditioning system,R134 a and R407 c were respectively employed as refrigerants and charged into the system. Tests were conducted in the enthalpy difference laboratory in terms of the exhaust temperature,refrigerating capacity,heating capacity,input power and the COP,which were determined within temperature range-25-15 ℃ and 30-70 ℃ respectively for evaporation and condensation. Results show that the refrigerating and heating capacities of the system closely correlated with the fluctuation of the evaporation temperature,and the condensation temperature had a great effect on the input power of the compressor. Results also reveal that there is 27. 6% increment in the mean COP by R407 c when the system operates in heating mode in winter in comparing with 4. 3% increment by R134 a when the system is in refrigeration mode in summer. It suggests that R407 c is more suitable for an air conditioning system running at a lower temperature,and selection of R134 a was more reasonable for an air conditioning system running at a higher temperature.