热泵热水器中R1234ze(E)/R32替代R22的可行性分析

Feasibility of R1234ze(E)/R32 Mixture Used as Altemative for R22 in Heat Pump Water Heater System

本文分析了R1234ze(E)/R32混合工质的环保及安全特性、溶油性、温度滑移和饱和蒸气压力特性,对不同配比R1234ze(E)/R32混合工质在热泵热水器系统中的循环性能进行了理论分析,并与R22进行比较。结果表明:R1234ze(E)/R32混合制冷剂对环境影响较小,可燃性低,具有与R22相似的饱和蒸气压力曲线;可在较大配比范围实现对R22的替代,且存在最优质量配比(45/55),对应的COP_h达到4.744,较R22系统提高了8.81%,单位质量制热量和单位容积制热量分别增加了3.59%和27.59%,压比和排气温度均减小,但冷凝压力略有升高。

For the mixed refrigerant composed of R1234ze(E)and R32,their environmental and safety characteristics,lubricants compatibility,temperature glide characteristics and saturated vapor pressure curves as well as their cycle performance of heat pump are analyzed and compared with those of R22 in this paper.The results show that R1234ze(E)/R32,which has small impact on the environmental,low flammability and presents similar saturated vapor pressure curves to R22,can substitute for R22 in heat pump water heater in a larger scope of mass fraction of R32,and there exists an optimal mass fraction(45/55)of R1234ze(E)/R32,whose COPh is 4.744 which is 9.03%higher than that of R22.Compared with R22,the unit mass heat capacity and unit volumetric heat capacity of R1234ze(E)/R32(45/55)increases by 3.65%and 27.64%respectively,and its pressure ratio and discharge temperature of compressor are lower,however,its system condensation pressure is a little higher.