Performance investigation and exergy analysis of vapor compression refrigeration system operated using R600a refrigerant and nanoadditive compressor oil

Compression of vaporized refrigerant is the essential process of the refrigeration cycle which is performed by using a compressor. The amount of power consumed by a refrigeration system is governed by the work input given to its compressor, which also determines the COP of the system. By reducing the work input given to the compressor, the power consumption of refrigerator is reduced along with the improvement in its COP. Nowadays, nanoparticles have emerged as the new generation additives in various working fluids because of their remarkable ability to improve the heat transfer, tribological and other thermophysical properties of the base fluid. In such a vein, we propose a compressor oil based nanofluid prepared by dispersing nanoparticles into the conventional compressor oil. In the present study, four samples of nanoadditive compressor oil were prepared by dispersing the nanoparticles like Al2O3, TiO2, and ZnO into the conventional mineral oil as a lubricant. The tribological properties of this four samples were studied, out of which one sample gave a better lubrication and heat transfer properties which are considered as one of the key parameters for reducing work input to the compressor, this can result in reduced power consumption, with enhancement of COP. These results are analyzed experimentally by carrying out performance and exergy analysis in a vapor compression refrigeration system, using R600a as a refrigerant. The experimental results show that, there is an improvement of COP by 14.61% and exergy efficiency by 7.51%. Also, the efficiency defect in the major components of vapor compression refrigeration system has been reduced effectively.