Simulation and experimental study of thermal storage systems for district cooling system under commercial operating conditions

Abstract

The use of ice as a phase change material (PCM) for such latent thermal energy storage (LTES) systems has been well established in industrial thermal storage. Organic phase-change materials (PCMs) such as paraffin waxes present advantages over ice for LTES systems in commercial air conditioning application due to higher phase-change temperatures and negligible volume expansion. In this study, an encapsulated ice thermal storage (EITS) system was analysed, modelled via COMSOL and validated with operating data. The numerical model is employed to analyse a similar theoretical encapsulated PCM (EPCM) system under similar and altered operating conditions using experimentally-derived thermal properties. Key results from this work revealed that the EPCM system is able to attain higher cold energy storage capacity of up to 3 times that of a reference chilled water tank and 9.37% more than that of the EITS under high flow conditions due to greater degrees of solidification. The effect of heat transfer fluid flowrate on solidification ratio and energy charged is also observed to be more pronounced in EPCM systems as compared to EITS systems.