DESIGN AND EXPERIMENTAL INVESTIGATION OF A VAPOR COMPRESSION REFRIGERATION SYSTEM USING LPG–R134A BLENDED REFRIGERANTS

Abstract

This experimental study evaluates the performance of a vapor compression refrigeration (VCR) system operating with pure R134a and blended R134a/LPG refrigerants under identical operating conditions. The objective is to assess the feasibility of LPG–R134a mixtures as an energy-efficient and environmentally friendly alternative to conventional R134a. Experiments were conducted by varying the mass fraction of LPG in the refrigerant mixture while maintaining constant and reduced total charge quantities. Key performance parameters, including compressor power consumption, pull-down time, and coefficient of performance (COP), were experimentally determined using an adiabatic calorimetric method. The results indicate that the R134a/LPG blended refrigerant significantly enhances system performance compared to pure R134a. At a reduced total charge of 400 g, a mixture containing 60% LPG and 40% R134a achieved a maximum COP of 0.902, representing an improvement of approximately 14% over the baseline R134a system. In addition, the blended refrigerant demonstrated lower compressor power consumption and improved cooling performance due to its higher latent heat characteristics. The reduction in total refrigerant charge further contributed to enhanced system efficiency. These findings suggest that R134a/LPG blends can serve as a promising alternative refrigerant for domestic refrigeration systems, offering improved energy efficiency with reduced environmental impact while mitigating safety concerns associated with the use of pure hydrocarbons.