A numerical investigation into the charge behaviour of a spherical phase change material particle for high temperature thermal energy storage in packed beds

This paper is concerned about the charge behavior of a spherical phase change material (PCM) particle for high temperature thermal energy storage in a packed bed. A numerical modeling approach is used in the work. The influences of heat transfer fluid (HTF) temperature, PCM particle size and heat transfer modes (conduction only, combined conduction and natural convection and thermal radiation) on the behavior are examined. The results show that the melting time increases with an increase in the PCM particle size or a decrease in the HTF temperature. Inclusion of the natural convection effect in the PCM region leads to a reduction in the melting time by about 16%. Thermal radiation at the boundary accelerates the melting process of the PCM and intensifies the natural convection.