Liquefied Petroleum Gas (LPG) refrigerant consist the mixture of propane and butane in the ratio 60/40% by mass and has the characteristics of low global warming potential, non - ozone depleting potential and high energetic efficiency has improved the performance of domestic refrigeration in the recent years. Effect of limit charge in vapour compression refrigeration system plays an important role in the power consumptions. On the other hand, the flammability of LPG refrigerant requires safe limit charging approach. This work experimentally analyzed the performance of 20 and 30 g charges of LPG refrigerant with a small portion 0.1g/litre 15nm TiO2 nanoparticle lubricant on a modified 100 g charge R134a domestic refrigerator working with a 110 watts with hydrofluorocarbon (HFC) compressor. Analyses were carried using RefProp 9.1 NIST software. The result reveals that cooling capacity improved with 131 and 122% while compressor work input reduces with 45.5 and 40% and these brought about reduction in pressure ratio of 42.7 and 30.2% and reduction in COP by 27.1 and 44.5% for 20 and 30 grams charge of 0.1 g/ litre LPG nanolubricant when compared with pure R134a refrigerant. Low safe limit charges of LPG refrigerant with nano lubricant found improved the efficiency of a domestic refrigerator. Therefore LPG-nanolubricant can serve as a replacement for R134a in vapour compression refrigeration system.
