关键词: 热力学, 压缩机, 湿压缩, 系统性能, 优化

Abstract: Wet compression used in R32 refrigeration system can reduce compressor discharge temperature effectively,but its impacts on system performance need more studies. Based on the theoretical analysis of cycle thermodynamic calculation,this paper studies the variation trends of R32 refrigeration system parameters under different operating conditions for seeking the optimal of suction refrigerant. Utilizing the frequency conversion rolling rotor compression refrigeration cycle test bench,a series of experiments were done by changing the electronic expansion valve and compressor's frequency. Theoretical analysis shows that,when compressor sucks vapor-liquid mixed refrigerant,the system shows better performance than that with superheat suction refrigerant;when the suction refrigerant transforms from superheating vapor to two-phase flow with little liquid,the discharge temperature rapidly reduces,cooling capacity and COP increase firstly and then decrease. When compressor suction refrigerant quality ranges from 0.90 to 0.93,the theoretical maximum COP exists. Experimental results showed that,when the suction refrigerant quality ranged from 0.96 to 1.0,cooling capacity was improved by 5%-10% over conventional refrigeration applications that the control superheat degree was at 5℃. Meanwhile,the discharge temperature decreased by 8%-16%,COP increased about 5%-8%,and system pressure ratio was decreased,and system performance reached the optimum state.

Key words: thermodynamics, compressor, wet compression, system performance, optimization