EXPERIMENTAL AND NUMERICAL INVESTIGATION OF A HOUSEHOLD REFRIGERATOR INTEGRATED WITH A PCM BASED CONDENSER

Abstract

Today, in India, household refrigerator consumes about 21.95 TWhr of energy and the number newlineis still advancing due to 8% annual growth in the number of refrigerators. With such a large newlinevolume of the refrigerators, a slight improvement in energy efficiency of the refrigerator can newlineresult into substantial energy saving. Comprehensive literature survey suggests that ambient newlinetemperature affects significantly to the energy consumed by the refrigerator and it is highest at newlinethe noontime. newlineIn order to mitigate the impact of higher ambient temperature at the noontime, this thesis work newlinepresents experimental and numerical investigation of a domestic refrigerator incorporated with newlinea phase change material (PCM) based condenser in parallel to the conventional condenser for newlinethe climatic conditions of India. It is proposed to operate the refrigerator with the PCM based newlinecondenser when the ambient temperature is higher during the daytime. While at other times, newlineair cooled condenser is used. newlineAn experimental set up is built in the laboratory on a household refrigerator of 175 liters. The newlinePCM chosen for the experimentation is a phase-stabilized FS21, having latent heat storage newlinecapacity of 143 kJ kg-1 and melting temperature range of 18-23°C. newlineThe experimental analysis showed that the PCM based condenser brings down the condenser newlineexit temperature and it stays lower until PCM melts completely with the selected PCM (FS21). newlineThere is a reduction in energy consumption of ~15% in 3½ hrs of refrigerator experimentation newlinewith the proposed modification. newlineTo study the performance of refrigerator with other potential PCMs based condenser, newlinedevelopment of a numerical model is also presented in this research work. Due to complexities newlinesuch as transient moving mesh, involvement of natural convection and heat conduction modes newlineof heat transfer, lack of standard numerical settings for the melting process and lower thermal newlineconductivity associated with the PCM makes difficult to solve three-dimensional (3D) model newlineof the PCM based heat exchanger.