Thermal performance of domestic refrigerator with multiple phase change materials: Numerical study

Abstract

This paper presents a physical model to study the energy efficiency of a residential refrigerator containing multiple phase change materials (PCMs). This model was validated using experimental data from published literature. The impact of varying parameters, such as PCM thickness (from 3 up to 7 mm), internal load (from 0 up to 20 W) and external temperature (from 15 up to 30 °C), on the energy performance of the domestic refrigerator was described. It was found that the melting temperature of the PCM should be chosen based on the estimated thermal load of the refrigerator. As well, the PCM thickness has a significant impact on the system's autonomy and performance. Hence, the compressor downtime increases from 344 min, using 3 mm of water, to 530 min using 5 mm and up to 720 min using 7 mm. The simulation results also indicate that the refrigerator air temperature when the eutectic solution is used as PCM is lower than that of using water. Besides, using multi-PCMs (water and eutectic solution) in parallel maintains the air temperature between 4 and 6 °C.