Development of Nanolubricant Using Aloe Vera Plant to Enhance the Thermal Performance of a Domestic Refrigeration System

Abstract

Power consumption is a significant issue in developing countries, and the refrigerator is one of the largest consumers of electricity. Nanoparticles functioning as additives to refrigerants or lubricating oils help reduce compressor work and reduce the power consumption of refrigerators. In this study, zinc oxide nanoparticles were developed using Aloe Vera leaves and dispersed in mineral oil to reduce the compressor work and increase the performance of a domestic vapour compression refrigeration system. After the successful synthesis of the nanoparticles, spectroscopical investigations using EDS revealed the nanoparticles to have 73.31% zinc, 20.19% oxygen and 6.40% carbon indicating a significant phase of zinc oxide. Microstructural studies on the nanoparticles revealed an average nanoparticle size of 4.68 nm within the nanometric range. The nanoparticles were dispersed in mineral oil in concentrations of 0.5 g/250 ml, 0.75 g/250 ml, 1 g/250 ml, 1.25 g/250 ml and 1.5 g/250 ml of the oil and fed into the compressor to check the effect of each concentration on the performance of the refrigerator. The control sample contained pure mineral oil. The system was monitored for 225 minutes per sample, and coefficient of performance was determined. The results indicate an increase in COP by 14-15% from 0.4 wt% and 0.6 wt% respectively.