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Due to their high rate of heat transfer and better thermo-physical properties, the application of nanoparticles in cooling systems results in better enhancement, improved reliability and efficiency of refrigeration and air conditioning systems, and hence, they are widely used in domestic and industrial sectors. It has been found that the major contribution to global warming potential (GWP) and depletion of ozone layer (ODP) is due to the over usage of conventional refrigerants; thus, the utilization of nanoparticles in refrigeration and air conditioning systems is highly recommended. The application of nanorefrigerants not only increases the thermal conductivity and heat transfer characteristics but also improves the coefficient of performance (COP) effectively, leading to energy savings. This article comprises the theoretical analysis of R134a-Al2O3, R134a-ZnO, R134a-TiO2 and R134a-CuO mixtures as replacements of pure R134a refrigerant in vapour compression refrigerants (VCRs). For comparison, the COP and refrigeration effect (RE) of the system with and without the addition of nanoparticles are determined from reported observations. It is concluded that the COP of a refrigeration system with added nanoadditives in refrigerant fluid is higher than that of systems running with pure refrigerant fluid. Around 38% increase in COP has been recorded in this study. Moreover, CuO nanoparticles showed high value of COP when blended with R134a compared to other nanoparticles. The COP of the refrigeration systems varies with the type of refrigerants used in the system.
nanoparticles, nanorefrigerant, ozone depletion potential, vapour compression refrigeration
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