Numerical simulation of phase change heat transfer in cold storage sphere

Heat transfer equations describing the phase change in a cold storage sphere were set up. The control volume method was used to construct finite differential equations of these equations. Temperature curves in an ice sphere during phase change processes were measured by experiments. The numerical results of these temperature curves agree well with experimental ones. It is found that phase change time for a sphere of 100 mm diameter is 2.4 times of that needs for a sphere of 50 mm diameter. When the convective heat transfer coefficient is at a low value, increase of the coefficient can decrease phase change time remarkably. Phase change time increases linearly with the initial temperature of ice sphere. When the temperature of heat transfer fluid is near 0C, change of the temperature influences phase change time sharply. The numerical results can be used to determine the heat transfer parameters of an ice sphere for thermal storage usage.