Experimental investigation of phase change material (PCM) thermal energy storages with and without metal foam at different temperatures

Abstract

This paper presents an experimental investigation of phase change materials (PCM) thermal energy storage. The experimental unit consists of a square channel with a single flow stream having distilled water as a heat exchange fluid. RT-42 is used as a thermal energy storage and the overall system is designed in two configurations i.e. with and without aluminium metal foam having a porosity of 95%. Each configuration is analysed and compared for two temperature variations i.e. at 55 °C and 65 °C, respectively. The study reveals that the heat storage rate in metal foam (MF) integrated PCM thermal energy storage is enhanced to ~3-4 times as compared to the setup without metal foam. In metal foam PCM energy storage, the temperature distribution is uniform and heat transfer is due to conduction as well as convection, while in case of pure PCM, there exist a temperature gradient within the thermal storage and the heat transfer is slower due to convection phenomenon. It is also observed that the heat transfer rate for 65 °C is comparatively greater than that of 55 °C for both systems as the higher operating temperatures lead to higher heat flux. However, operating at high temperatures is less feasible as the setup is more prone to PCM leakages.