The Experimental Study On Non-azeotropic Refrigerant In High Temperature Air-conditioner

High temperature air-conditoners often run over a wide temperature range and in high temperature work conditions,so some commonly used mid-temperature refrigents are not suitable for high temperature any longer.It is a key facter to search for a proper kind of refrigent to solve the problems of developing and manufacturing high temperature air-conditioners,which is environmentally friendly and has good thermodynamic properties.The major work of this thesis was to find a proper kind of refrigent which is suitable for circulating in high temperature air-conditioners.Non-azeotropic mixture R22/R142b's properties were analyzed in this thesis at first, and it was found that it is feasible for high temperature air-conditioners to use in theory,and not only the thermodynamic properties of it are fairly good but also it is environmentally friendly. By using R22/R142b's thermodynamic properties, the main components of the high temperature air-conditioners which originally used R12 as working fluids were checked and analyzed. Then the variation of the running performance with different mass fractions was studied by method of experiment and simulation.It was found that the cooling capacity is fairly high and changes smoothly over a wide temperature range of 30～75 o C when the mass fractions of R22/R142b range from 5/5 to 7/3 ;Besides, both the exhaust temperature and the exhaust pressure are not so high that they can damage the air-conditioner.Meanwhile,The optimal refrigerant charge was also tested in high temperature work conditions in this thesis,as a result, the sample machine ran relatively well when the refrigent charge was about 2.65kg.Good idea and methods for the improvement of high temperature air-conditioners ,on the premise of relatively low cost in the technological transformation ,were provided through the study on the refrigerant replacement in high temperature air-conditioners in this thesis. Reference was also provided for the study on high temperature heat pumps by the research method and the results of experiment and simulation in the thesis.