Compared with the conventional portable heat transport, this paper proposes the spherical encapsulation arranged in the thermal storage tank. A new kind of PCM (0.4% nanocopper+ 99.6% erythritol) with latent heat of 362.2 kJ/kg was encapsulated in stainless steel ball. The validity of various models developed and complexity required for a given problem is not suitable for spherical encapsulation during heat transport. Take the spinning during heat transport into consideration, the heat transfer process was analyzed for an encapsulated phase change material and its theoretic model for the PCM interface was established. In order to validate the model, the experiment was conducted for the temperature distribution change. During the heat release, the solid liquid interface moved from the spherical shell to ball center, and it was found that interface moving speed increases when the ambient temperature reduces. The research is also investigated for effect of the ball size on the interface moving, which has an equally agreement with the theoretical model. (C) 2015 Elsevier Ltd. All rights reserved.