Exergetic Performance of a Domestic Refrigerator Using R12 and its Alternative ‎Refrigerants

Abstract

Production and use of R12 and other chlorofluorocarbon refrigerants will be ‎prohibited completely all over the world in the year 2010 due to their harmful ‎effects on the earth’s protective ozone layer. Therefore, in this study, the exergetic ‎performance of a domestic refrigerator using two environment-friendly ‎refrigerants (R134a and R152a) was investigated and compared with the ‎performance of the system when R12 (an ozone depleting refrigerant) was used. ‎The effects of evaporator temperature on the coefficient of performance (COP), ‎exergy flow destruction, exergetic efficiency and efficiency defect in the four ‎major components of the cycle for R12, R134a and R152a were experimentally ‎investigated. The results obtained showed that the average COP of R152a was ‎very close to that of R12 with only 1.4% reduction, while 18.2% reduction was ‎obtained for R134a in comparison with that of R12. The highest average ‎exergetic efficiency of the system (41.5%) was obtained using R152a at ‎evaporator temperature of -3.0oC. The overall efficiency defect in the refrigeration ‎cycle working with R152a is consistently better (lower) than those of R12 and ‎R134a. Generally, R152a performed better than R134a in terms of COP, ‎exergetic efficiency and efficiency defect as R12 substitute in domestic ‎refrigeration system‎