Experimental evaluation of refrigerants R290, R32 and R410a in a refrigeration system originally designed for R22

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.The present article focuses on the climate performance of three different refrigerants used to replace the hydrochlorofluorocarbon (HCFC), R22, for common refrigeration applications. The original system consists of a small commercial refrigeration system, which provides nominal refrigerating capacity of 15 kW. The condition of replacement of R22 by these alternative fluids (R290, R32 and R410A) represented a drop-in operation; there were no changes in the basic cycle components during the tests, with the exception of the lubricating oil. Experimental tests were carried out in steady state condition and throughout the tests the compressor had its entire speed range explored for different levels of modulation of the electronic expansion valve (EEV), thus enabling the realization of a complete thermodynamic analysis. The use of the hydrofluorocarbon (HFC), R32, which has a low global warming potential (GWP) and zero ozone-depleting potential (ODP) guaranteed good efficiency to the refrigeration system. The results showed regular conditions of efficiency of the experimental facility operating with the blend R410A. Finally, the use of the hydrocarbon (HC) resulted in the maximum values for the coefficient of performance, COP.