Energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

According to Kyoto protocol, R134a must be phased out soon due to its high global warming potential of 1430. In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture (composed of R134a and LPG in the ratio of 28:72 by weight) as an alternative to R134a in a vapor compression refrigeration system. Performance tests were performed under different evaporator and condenser temperatures with controlled ambient conditions. The results showed that the R134a and LPG refrigerant mixture has a higher coefficient of performance and lower compressor discharge temperature and pull down time as compared to R134a by about 15.1-17.82%, 2.10-13.86% and 1.01-5.90% respectively. Furthermore, the miscibility of R134a/LPG with mineral oil as a lubricant was also found good. In conclusion, the mixing refrigerant R134a/LPG proposed in this study seems to be an appropriate long-term candidate to replace R134a as a new generation refrigerant of VCRS, because of its well environmentally acceptable properties and its favorable refrigeration performances.