The thermal performances of a refrigerator incorporating a phase change material

Abstract

In this paper, a Phase Change Material (PCM) has been incorporated within the cabinet of a refrigerator, attached to the bare tube evaporator placed below the racks, with the aim of analysing the variation of temperatures and compressor operation, among others. The effect of different control settings (hysteresis) on the performance of such a system, equipped with tap water as PCM, is investigated. Furthermore, the impact of the variation of the ambient temperature and the product mass is highlighted. Two novel parameters are introduced: the first one to estimate the utilisation of the PCM during the cyclic operations of the refrigerator, and the second one is used to evaluate the fluctuation of the product temperature within the cabinet. Experimental results show that the introduction of the PCM has led to a noticeable reduction of the temperature gradient within the cabinet and the fluctuations of product temperature ensuring better conservation conditions, and to extend the OFF time of the compressor. The tests also show that with PCM, hysteresis has lower impact on the fluctuation of the product temperature, ON-time ratio and energy consumption of the refrigerator than without it. On the contrary, the product temperature distribution is more affected by the hysteresis with PCM than without, leading to a better uniformity with higher hysteresis.