不同滑移温度混合工质在双温冷水机组中的性能

Performance of mixed refrigerant with different temperature glides in dual temperature water chillers

为了研究混合工质滑移温度对双温冷水机组制冷性能的影响,通过实验测定了R32/R236fa(质量比0.6∶0.4)、R1270/R600(质量比0.7∶0.3)、R32/R600(质量比0.5∶0.5)3种混合工质在冷却水进、出口温度为32、37℃,低温冷冻水进、出口温度分别为7、12℃和高温冷冻水进、出口温度分别为18、23℃时机组的性能参数.并基于混合工质换热时的非线性温焓关系分析了混合工质泡、露点温度及滑移温度对制冷量的影响.研究结果发现:R32/R600低温制冷量最大,压缩机功耗最大;R1270/R600低温制冷量最小,高温制冷量最大,压缩机功耗最小.R32/R236fa低温COP值最大,高温制冷量最小,高温COP值最小.R32/R236fa的低温冷量与高温冷量的比值α值最大,R1270/R600的α值最小.混合工质的泡、露点温度参数对低温换热器制冷量影响较大,滑移温度对高温换热器制冷量影响较大.实验结果可为不同冷负荷、湿负荷条件下的双温冷水机组的设计提供参考.

To study the influence of temperature glide of mixed refrigerant on the performance of dual temperature water chillers, the performance parameters of the chillers with R32/R236fa(0.6 ∶ 0.4),R1270/R600(0.7 ∶ 0.3)and R32/R600(0.5 ∶ 0.5) mass fractions were measured by experiments at the inlet and outlet temperatures of 32,37 ℃, and at the inlet and outlet temperatures of low and high temperature chillers at 7,12 ℃ and 18,23 ℃, respectively.The influence of the bubble point and dew point temperature and glide temperature of mixed refrigerants on refrigeration capacity was analyzed based on the nonlinear change characteristics of temperatures and enthalpy in the heat transfer of mixed refrigerants. The results show that R32/R600 has the largest low-temperature refrigerating capacity and the largest compressor power consumption, and R1270/R600 has the smallest low-temperature refrigerating capacity, the largest high-temperature refrigerating capacity and the smallest compressor power consumption. R32/R236fa has the largest low-temperature COP value,the smallest high-temperature refrigerating capacity and the smallest high-temperature COP value. The α value of R32/R236fa is the largest, and the α value of R1270/R600 is the smallest.The temperature parameters of the bubble and the dew point of the mixed refrigerant have a great influence on the refrigeration capacity of the low-temperature heat exchanger, and the glide temperature has a great influence on the refrigeration capacity of high-temperature heat exchanger. Experimental results can provide a reference for the design of dual temperature water chillers under different cooling and wet load conditions.