Theoretical And Experimental Investigation On The Working Fluids For The Moderate And High Temperature Heat Pump

From the view of utilizing waste heat, saving energy and environment profit, and to satisfy the requirement of higher working temperature for heat pump, in this paper, some environmentally benign working fluids at condensing temperature from 70oC to 160oC had been searched for the moderate and high temperature heat pumps in both theoretical and experimental aspects. For the span of the working temperature related to the moderate and high temperature heat pumps is great, the range of the working temperature had been divided into three temperature parts, and typical working condition had been determined based on the division. Through analysis and comparison of the theoretical cycle calculation results, some working fluids had been recommended to the different temperature parts. According to the theoretical calculation results of the pure working fluids, six mixtures M1-M6 had been combined and studied. Some thermodynamic properties of the six mixtures, such as temperature glide, non-ideal liquid had been given.The principles of fare comparison for circulating performance between working fluids and experimental methods were investigated. The existing air-conditioning test system had been improved on the base of experimental study. Compared with former experimental results for HCFC22 and some others, pressure drop at working fluid side of evaporator had been greatly decreased and cooling capacity and COP had been improved. The improvements on expansion device made the system be used for experimental study of differential working fluids between which the pressure is much larger different.The experimental study for moderate and high temperature heat pump working fluids had been done in the improved test system. The working conditions for M4B were evaporating temperature of 52oC and condensing temperature of 95oC, and water temperature out of condenser was 94.5oC under normal experimental flux. The study has broken through the highest temperature level in existing papers.The theoretical and experimental results have indicated that the working fluids and mixtures studied in the paper have potentials as moderate and high temperature heat pump working fluids in different temperature spans.