Validation of a mathematical model for encapsulated phase change material flat slabs for cooling applications

A one-dimensional liquid-based model for a flat slab phase change thermal storage unit was developed. The model allows for varying wall temperatures along the direction of flow and integrates a convective boundary layer using a previously developed algorithm, which is employed to iteratively calculate the liquid fraction and the temperature of each phase change material (PCM) node. The melting and freezing processes are analysed based on the temperatures of the heat transfer fluid nodes, the wall nodes and the PCM nodes during melting and freezing. The mathematical model developed was validated using two sets of experimental data obtained from tests using a PCM having a melting point of −26.7 °C and a liquid glycol based heat transfer fluid. The numerical results show a good agreement with the experimental ones.

► We modelled the heat transfer of a flat plate phase change thermal storage unit.
► The model is based on liquid heat transfer fluid.
► The numerical results show a good agreement with the experimental ones.
► The model can predict the melting time accurately.