Experimental Study on Dynamic Heat Release Performance of Water Tank with Phase Change Materials

Abstract

Solar heating system has raised much attention due to the global energy shortage and environment pollution. The dynamic heat release performance of water tank (WT) with phase change materials (PCM) plays an important role in the operation of solar heating system, while seldom available literatures focused on this research topic. In this paper, an experimental system for heat release of the WT-PCM was established. The temperature variations of the water and the PCM during heat release of the WT-PCM and the traditional water tank were measured respectively, and their dynamic heat release performance were also analyzed based on the measured data. The results are as follows: the heat release of the WT-PCM can be divided into three phases: sensible heat before phase change, latent heat during phase change and sensible heat after phase change, and the water temperature will be temporarily heated after the sudden drop; the water supply temperature decline rate of both tanks will increase dramatically at the initial stage of heat release, when the PCM temperature is reduced to 50℃, the water supply decline rate of the WT-PCM is less than that of the traditional water tank, while when PCM is completely solidified, the water supply temperature decline rate of the WT-PCM is more than that of the traditional water tank. The heat release performance of the WT-PCM is much better than that of the traditional water tank. The research results can provide useful reference for engineering application of the WT-PCM.