Analysis of PCM solidification between parallel plates for cooling applications

The energy storage in the phase change material, such as water, is a well-accepted technology and is expanding in several engineering and building applications. In this study, a thermal model based on pure conduction to describe the solidification process in a parallel plate storage system is developed. For the solution of this model, the governing equations for the solid and liquid phases and the interface moving are discretized using the finite difference approximation and totally implicit approach with variable time step. The computational code representing the thermal model for the phase change process around the parallel plates was tested and validated against available numerical and experimental results, showing good agreement. The energy stored, interface position, interface velocity and the time for complete solidification are presented and discussed in terms of the temperature of the cold plate and the distance between the plates. As the temperature on the surface of the plate decreases, there is a reduction in the time to complete phase change and a higher solidification rate. However, increasing the distance between the plates contributes to a longer time for complete solidification. The contribution of this study through the adopted model and solution method aims at a provisional way of obtaining an evaluation of this type of storage configuration and expanding its use in commercial applications and scientific research, in addition to predicting its thermal performance parameters quickly and accurately.