Performance of Al2O3-SiO2/PAG composite nanolubricants in automotive air-conditioning system

Abstract

• Performance investigation of Al 2 O 3 -SiO 2 /PAG composite nanolubricant in AAC system. • Investigation is conducted using 60:40 ratio for up to 0.06% volume concentration. • The highest COP enhancement of 28.10% was recorded at 0.015% volume concentration. • Compressor work and power consumption were reduced to 25.26% and 19.70%, respectively. • Al 2 O 3 -SiO 2 /PAG nanolubricant at 0.015% concentration was recommended for AAC system. Automotive air-conditioning (AAC) system performance must be improved to reduce energy consumption and promote energy efficiency. Efficiency of the AAC system can be increased by applying the right lubricants. With a combination of different metal oxide components and composition ratios, composite nanolubricants are expected to outperform single-component nanolubricants in improving AAC system performance. The present work was undertaken to investigate the performance of the AAC system using combination of Al 2 O 3 -SiO 2 /PAG composite nanolubricants with composition ratio of 60:40 for 0.005 to 0.06% volume concentrations. The experiment was undertaken with an initial refrigerant charge of between 95 and 155 g and a compressor speed of between 900 and 2100 rpm. The efficiency of the AAC system was assessed by the determination of cooling capacity, compressor work, coefficient of performance (COP) and power consumption. The highest average COP enhancement was recorded 28.10% at 0.015% volume concentration. Al 2 O 3 -SiO 2 /PAG composite nanolubricants attained the highest COP value of 9.19 for 155g at compressor speed of 900 rpm. In addition, for 0.015% Al 2 O 3 -SiO 2 /PAG composite nanolubricants, the cooling capacity was enhanced up to 65.21% while the compressor work and power consumption were reduced up to 25.26% and 19.70% respectively. Therefore, 0.015% Al 2 O 3 -SiO 2 /PAG nanolubricants was highly recommended for the maximum efficiency in AAC system performance.