Supercooling Simulation of Latent Heat Based Storage : A simulation model built in COMSOL Multiphysics

Abstract: The energy demand in the building sector makes up a large portion of our energy consumption. The industrial sector is also energy intense and oftentimes loses a great deal as surplus heat. To bridge this gap a Mobile Thermal Energy Storage unit could be applied to store industrial waste heat and make use of it in the building sector to produce sanitary hot water. The objective of this work will be to produce a numerical simulation model of the discharge process for the storage unit, including the supercooling phenomenon observed to be taking place during solidification of the phase change material (Erythritol). Previously acquired experimental performance measurements will be compared to the numerical results to confirm validity. COMSOL Multiphysics was used to simulate different sub-parts of the module, including fluid dynamics. The cut-down into sub-parts was done to reduce the amount of required elements. The results showed that the numerical model could produce similar thermal behavior as the experimental unit including the supercooling phenomenon. The model did however not include the natural convection that would take place in the Erythritol, which could have led to more accurate results.