Experimental Research on the Performance of Environmental Friendly Refrigerant Mixtures in a Vapour Compression Refrigeration System

Abstract

Today's refrigeration and air-conditioning industry is adopting chlorine- and fluorine-free working fluids, because chlorine is the cause of depleting the ozone layer, and fluorine is the cause of global warming. CFC12 is a more suitable refrigerant recognized in vapor compression refrigeration systems. It was phased out in developed countries in 1996. It is recommended to use HFC134a for replacing CFC12 in vapor compression refrigeration systems. But HFCs have a high global warming potential. The Kyoto Protocol aims to reduce the whole GHG emissions by at least 5-times over the 1990 level during the commitment period from 2008 to 2012. Therefore, in the near future, the production and utilization of HFC134a will be ended. There are millions of heat pumps and air-conditioners in refrigeration systems that use CFC12 and HFC134a in the world that must be properly retrofitted under the aforementioned phase-out. However, there are few studies on the replacement of HFC134a refrigerant. This motivates the use of some available environmentally friendly fluids to replace the new product lines of CFC12 and HFC134a to study the performance of the new product line of vapor compression refrigeration systems. But none of them are environmentally acceptable substitutes. In the work of this project, refrigerant R290/R600a (68/32% by weight), R290/R600 (79/21% by weight) is used for the performance of vapor compression refrigeration system), LPG (R290/R600/R600a-33/53)/14 wt.%) and LPG/R134a (60/40 wt.%) have been experimentally studied as modifications of CFC12 and HFC134a. Finally try to predict system performance under the action of a magnetic field. Six magnets are placed on the full liquid pipeline at the outlet of the condenser, and each magnet has a level of 4000 Gauss. Due to the magnetic field, the power consumption of the compressor is decreased by 2.5%, and the COP is reduced by 2.4%. The results of this study prove that the new alternative refrigerants R290/R600a (68/32 wt.%) and R290/R600 (79/21 wt.%) mixtures can well replace CFC12 and HFC134a, and can be used without any modification. It can be used to transform the old system. The refrigerants LPG and LPG/R134a (60/40% by weight) can be used for higher evaporation temperature applications.