The Effect of Radial Porosity Oscillation on the Heat Transfer Performance in Packed Bed Latent Heat Storage System
Abstract
The porosity oscillates along the radial direction in packed bed latent heat storage (LHS), which would cause the non-uniformity of flow field and then affect the heat transfer performance at different positions. In this paper, a three-dimensional (3D) packed bed LHS system was established to investigate the effect of radial porosity oscillation on flow and heat transfer, and the model was validated by experimental data. A series of cylindrical surfaces along the radial direction were intercepted to illustrate the reason for radial porosity oscillation. The numerical results show that the radial velocity distribution of heat transfer fluid (HTF) and the radial temperature distribution of phase change materials (PCMs) are consistent with the distribution of radial porosity. The evolution of liquid fracitons indicates that PCMs melt faster at the surfaces with higher porosity and PCMs melt faster on the HTF side. This work can provide guidance for the application of packed bed LHS system to solar energy storage in the future.