Capacities and irreversibility of the vapour compression refrigeration system’s components using aluminium oxide (Al₂O₃) based nanolubricants

Abstract

Hydrochlorofluorocarbon and chlorofluorocarbon refrigerants commonly used in vapour compression refrigeration system (VCRS) have been phased out due to their negative impact on the ecosystem. R134a and R600a refrigerants were considered as their replacement, but they possess low thermal properties, thereby affecting the performance of the VCRS. In this study, the effect of varying aluminium oxide (Al2O3) nanoparticle size (10 nm, 20 – 30 nm and 80nm) and volume concentration (1%, 3%, 5% 10% and 20%) on the capacity and exergy efficiency of each component of VCRS for the optimisation of the VCRS performance and reduction of energy consumption was analysed using R134a and R600a refrigerants. The nanolubricant were prepared using the two-step method. The VCRS showed no significant deterioration in the performance of its components as confirmed for over 24 hours when nanorefrigerant was used. The compressor capacity of nanorefrigerant was lower than that of pure refrigerants while the addition of nanoparticle enhanced the refrigeration effect. The exergy efficiency of the vapour compression system improved with the addition of nanoparticles into the system, the exergy destruction caused by friction in the compressor significantly reduced, thereby reducing the energy consumed by the system.