Capacities and Irreversibility of the Vapour Compression Refrigeration System’s Components using Aluminium oxide (Al2O3) based Nanolubricants

Abstract

Vapour compression refrigeration systems (VCRS) are used for cooling and preservation. Hydrochlorofluorocarbons (HCFC) and chlorofluorocarbon (CFC) commonly used as refrigerants have been phased out due to their negative impact on human and the environment. R134a and R600a refrigerants have been proposed as replacement to HCFC and CFC refrigerants, but they possess low thermal properties. In this study, the thermal property of R134a and R600a were enhanced by dispersing aluminium oxide (Al2O3) nanoparticles of 10 nm, 20 – 30 nm, and 80nm size, hence, enhancing the performance of the VCRS. Nanolubricant were prepared using the two-step method with varying nanoparticle volume concentrations of 1% to 20%. The capacities and irreversibility of each component of the VCRS were analysed using Al2O3 nanolubricant as the compressor oil. The heat transfer characteristics and 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 was significantly reduced with nanolubricant leading to lower power consumption by the system. The lower nanoparticle size (10 nm) was more efficient than the larger sizes. The heat transfer characteristics and exergy efficiency of R600a and its nanorefrigerants were better than that of R134a and its nanorefrigerants.

Keywords

• aluminium oxide
• efficiency
• capacities
• nanorefrigerant
• VCRS