Modeling of the discharging process of a heat storage tank filled with PCM to cover the heat demand of a building

摘要

The paper contains a brief description of calculations made for model tanks filled with PCM (Phase Change Material) that are used to cover the heat demand. The used model of the tanks takes into account the heat losses from the tanks' surfaces and the heat flux transferred between the PCM and water. The process of heat transfer in the PCM only uses the thermal conductivity phenomenon, which is appropriate for materials with high kinematic viscosity. The results of the change in thermal power of the storage tanks, outlet water temperature, PCM temperature and the amount of changing phase were considered significant. The article shows that the heat flux transferred between the PCM and the water depends primarily on the thermal resistance between the internal wall of the nodule and the moving front of the phase change from which energy is released. The mass flow rate of the water through the storage tanks has a lower impact on the speed of heat release. The article also shows the effect of PCM phase change and the flux of released heat on the temperature of the water flowing out of the tanks.