Exergy Analysis of Vapor Compression Refrigeration System Using R12 and R134a as Refrigerants

This paper deals with a comparative analysis of the influence of refrigerant on the performance of a simple vapor compression refrigeration system. The study is based on the refrigerants R12 and R134a. A computational model based on energy and exergy analysis is presented for investigation of the effects of evaporating temperature and degree of sub-cooling on the coefficient of performance and exergitic efficiency of the refrigerator. A considerable part of the energy produced worldwide is consumed by refrigerators. So it is crucial to minimize the energy utilization of these devices. The exergy analysis has been widely used in the analysis of all engineering systems including refrigerators. It is a powerful tool for the design, optimization and performance evaluation of energy systems. It is well known fact that the CFC and HCFC refrigerants have been forbidden due to chlorine content and there high ozone depleting potential (ODP) and global warming potential (GWP). Hence HFC refrigerants are used now-a-days. Many research papers have been published on the subject of replacing CFC and HCFC refrigerants with other types of refrigerants. This paper presents a comparative analysis of two refrigerants working in a one stage vapor compression refrigeration system with sub-cooling and superheating. These refrigerants are: Dichlorodifluoromethane (R-12) and Tetrafluoroethane (R-134a).