Performance improvement of R600a with graphene nanolubricant in a domestic refrigerator as a potential substitute for R134a

The efficiency of R600a an eco-friendly refrigerant with graphene nanolubricant was investigated and compared in a domestic refrigerator with R134a refrigerant a zero Ozone Depleting Potential (ODP) but higher Global Warming Potential (GWP) refrigerant. Type K thermocouples were attached to the refrigerator components to track the temperature of the system. Two pressure gauges were also attached to the compressor to determine the pressure at suction and discharge of the domestic refrigerator. A digital wattmeter was used to measure the refrigerator's compressor power consumption. The results showed the evaporator air temperature and pull-down time of R600a with graphene nanolubricant were lower compared to R134a. A higher COP was achieved with R600a in graphene nanaolubricant with an increase in cooling capacity within the range of 5.2% to 14.2% and the power consumption reduced within the range of 8.8% to 26.4%. Hence, R600a/graphene nano lubricant can successfully replace R134a/POE oil in a domestic refrigerator system.