Numerical model development for the prediction of thermal energy storage system performance: CFD study

A latent heat storage system to store available energy, to control excess heat generation and its management has gained vital importance due to its retrieve possibility. The design of geometry parameters for the energy storage system is of prime interest before experimentation. In the present study, a numerical investigation of 2D square enclosure filled with phase change material and discrete heating (L-d = 0.2 L, 0.4 L, 0.6 L, and 0.8 L) from the bottom while maintaining heater at constant heat flux has been carried out using the finite volume method. The enthalpy- porosity method was employed to model the phase change material melting process and optimum heater location predicted by solving fluid flow and heat transfer governing equations. Validation studies were conducted for two different geometries square and rectangular subjected to different boundary conditions. The results of the present work are depicted in terms of isotherms, liquid fraction, local phase change material temperature, and average phase change material temperature. It is observed both L-d = 0.2 L and 0.4 L locations have ensured the complete melting rate than other L-d = 0.6 L, 0.8 L locations. Moreover, energy stored by phase change material while heater at L-d = 0.4 L, 0.6 L, 0.8 L is decreased by 9.33%, 50.16%, and 53.05% respectively than compared to L-d = 0.2 L. Thus, the developed numerical model predicts that the enclosure type latent heat storage system is sensitive to the heater location for a given boundary condition.