Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.
A numerical model for a packed bed thermal energy storage (TES) system using phase change material (PCM) is presented. The storage system is to be utilized for a solar cooking application. Sunflower Oil is the heat transfer fluid (HTF) during charging cycles. The packed bed TES consists of spherical capsules filled with erythritol, as the phase change material. The model uses dual-phase mathematical heat transfer equations while the phase change phenomena inside the PCM capsules is analyzed by using the effective heat capacity method. Results from the model are validated with experimental results from literature. Numerical and experimental results are reasonably comparable. The effects of inlet temperature and the flow rate of the HTF on the temperature profiles of the packed bed are presented.