Experimental and numerical study on a lab-scale latent heat storage prototype for cooling applications

Abstract

Latent thermal energy storage systems using phase change materials (PCMs) represent an effective way of storing thermal energy because of high-energy storage density and the isothermal nature of the storage process. In the current study, the charging and discharging characteristics of a lab-scale latent heat storage (LHTES) prototype for cooling applications are experimentally and numerically studied. Two numerical models are developed to analyse the performance characteristics of the LHTES prototype: a conductive model and a conductive-convective model. Effective heat capacity (EHC) method is implemented to consider the latent heat of the phase change material. The governing equations involved in the models are solved using the finite element based software product, COMSOL Multiphysics, and the initial and the boundary conditions are determined on the basis of the data obtained from the experimental tests. Numerically predicted temperature variations of the models during charging and discharging processes are compared with the experimental data extracted from the lab-scale LHTES prototype, and a good agreement between them is found when the conductive-convective model is used, while high deviation is observed in case of use of the conductive model. Other results are presented in terms of the performance parameters such as charging/discharging time, energy storage charge/discharge rate, and melt fraction.