Cladding phase change materials in freezing and chilling zones of household refrigerator to improve thermal performance and environmental benefits

Abstract

The rapid change in the lifestyle of people makes refrigerator an inevitable appliance in every home and its sales are increasing every year. Since refrigerators account for the major share of energy consumption in homes, many technologies are adopted to improve its energy efficiency for environmental protection. The favourable properties of phase change material (PCM) in terms of its energy efficiency, attracted the use of the same in refrigerators. Cladding of PCM on evaporator and condenser showed improvement in overall performance of the system. In most of the previous studies, single PCM was selected for this purpose. Since a domestic refrigerator maintains different temperatures inside its compartments, cladding of multiple PCMs with freezing temperatures close to freezer and chiller compartments was considered for the experimental study. The energy and exergy efficiencies, along with economic and environmental benefits were studied to validate the proposed method of PCM cladding in a household refrigerator. To identify the appropriate PCM pair and cladding positions, seven configurations of PCM arrangements, represented as C1, C2, C3, C5, C5, C6 and C7 were used in the experimental study. Among the configurations, C5 and C7 showed better performance with 18.5 % reduction of energy consumption. The arrangements also complemented in reducing the number of ON/OFF cycles. Compared to conventional system, the proposed C5 and C7 configurations can reduce the total equivalent warming impact by 18.56 % and 14.43 % respectively.