Prediction Method of Cooling and Heating Characteristics of Solidified Phase Change Material with a Melting Model Introduced

Abstract

Synopsis: Phase change materials (PCMs) have a large heat capacity，and it is easy to charge and discharge their heat because their temperatures remain constant during phase change．PCMs with variable phase change temperatures are used in many applications. The charging and discharging characteristics of the PCMs change depending on the temperature of the phase change and the quantity installed. It is necessary for the efficient use of PCMs to elucidate their charging and discharging characteristics via simulation. Previously, the authors proposed a model that can express the supercooling and its removal along with its calculation method. The specific enthalpy distribution of a PCM is calculated using the one- dimensional equation of thermal conduction, and the temperature distribution is calculated using T-h characteristics. Fairly good agreements were obtained between the calculated and experimental values of the cooling process. However, there was a slight difference in case of the heating process. In this study, to improve the calculation accuracy of the heating process, the melting of a PCM was modeled and introduced into the calculation. The calculation result can express the characteristics of the partial progress of the melting of the PCM near the heat transfer surface. Furthermore, it is possible to predict the state of change in the temperature and heat quantity of the PCM with high accuracy. Thus, the effectiveness of the calculation method was confirmed.