A study of the influence of the fullerene C60 additives in compressor oils of various viscosities on the refrigerator performance parameters

The optimal choice of compressor oil and the use of nanoparticles as additives are a promising way to improve the efficiency of vapor compression refrigeration systems. The main barrier for the practical implementation of this approach in the industry is the impossibility of the theoretical prediction of the expected effects on the performance parameters of the refrigeration system. Experimental data for the cooling capacity, compressor power consumption and coefficient of performance (COP) during operation of the experimental setup (refrigeration system with Embraco Aspera EMT6152U compressor) have been obtained. R290 refrigerant and four different compressor oils (RENISO SP46 alkylbenzene oil with the viscosity of 46 mm 2 ·s -1 at 40 °С, and the same oil containing 0.223·10 -4  kg·kg -1 of fullerene C 60 , ProEco® RF22S polyester oil with the viscosity of 22.26 mm 2 ·s -1 at 40 °С and the same oil containing 6.837·10 -4  kg·kg -1 of fullerene C 60 ) have been used. The experiment was performed at the refrigerant condensing temperature of 318.5±1.0 K and in the evaporating temperature range of 252…271 K. When using the two pure oils, the compressor power varied by 2...3 %. The effect of the presence of fullerene C 60 on the compressor power was different for different oils. The use of a more viscous oil, as well as the presence of fullerene C 60 in the oil, leads to an increase in cooling capacity. The application of the less viscous oil ProEco® RF22S contributes to an increase in COP (up to 20 %) at the evaporating temperatures near 270 K and has no effect on the COP at low temperatures in comparison with RENISO SP46 oil. The presence of fullerene C 60 in both oils contributes to an increase in COP up to 15...20 % in the whole range of the studied evaporating temperatures. Therefore, the expediency of adding the fullerene C 60 into compressor oils in order to increase the energy efficiency of the vapor compression refrigeration system without its modernization has been confirmed