摘要

A physical model and a mathematical model of phase change during the process of heat transfer in a PCM (Phase Change Material) canister are suggested. Based on a theoretical analysis and calculation results of the PCM canister during the process of solidification, the model of improved void distribution in the PCM canister under microgravity is given. The phase change thermal storage process is numerically simulated with the use of the model of ignoring void cavity distribution, simple void cavity distribution, and improved void cavity distribution. The calculation results for three kinds of void distribution are compared and analyzed. The results show that the form of the void cavity distribution has a great effect on calculation results. The melting ratio of PCM has a great difference in the form of different void cavity distributions. The form of void distribution has a great effect on the process of phase change. Under the combined effects of local thermal resistance of void cavity and of the side wall of the PCM canister, it is the most difficult for them to melt during the period of sunlight.