A Study on Heat Transfer in a Thermal Storage System Using a PCM

Abstract

이 論文은 液相-固相의 相變化를 갖는 물질을 사용한 蓄熱系에서의 熱傳達에 관한 數値解를 얻기 위한 것이다. 蓄熱系의 相變化 물질은 그 初期溫度가 相變化 溫度 위의 어떤 일정한 온도이고, 水路에 面한 境界에서 對流熱傳達에 依해 冷却된다. 모든 물성값들은 각 상에서는 일정한 값을 가지고, 相이 변하면 다른 값을 가지나 密度만은 相變化에 따르는 변화가 없다고 假定한다. 境界에서의 溫度變化, 相變化率, 그리고 熱的 浸透 現像의 典型的인 溫度分布등의 結果과 나타나 있으며, 無次元 變數인 固相가 液相의 열전도係數比, 固相과 液相의 比熱比, Biot數 등의 변화에 기인한 結果의 比較도 나타나 있다.

The aim of this paper is to obtain various numerical results for heat transfer in a thermal storage system using a liquid-solid phase change material(PCM). The PCM slab of the thermal storage system is subjected to convective cooling at boundaries facing on the flowing water channel. The initial temperature of the PCM is a uniform temperature above the fusion temperature. It is asuumed that all the physical properties are constant for each phase but are different for different phase except density. The results such as temperature histories at boundaries, solidification rates, and typical temperature profiles fo thermal penetration phenomenon are represented here. Also the comparisons of those results for the change of various dimensionless parameters, e.g., thermal conductivity ratio of solid to liquid, specific heat ratio of solid to liquid, and Biot number are represented.

The aim of this paper is to obtain various numerical results for heat transfer in a thermal storage system using a liquid-solid phase change material(PCM). The PCM slab of the thermal storage system is subjected to convective cooling at boundaries facing on the flowing water channel. The initial temperature of the PCM is a uniform temperature above the fusion temperature. It is asuumed that all the physical properties are constant for each phase but are different for different phase except density. The results such as temperature histories at boundaries, solidification rates, and typical temperature profiles fo thermal penetration phenomenon are represented here. Also the comparisons of those results for the change of various dimensionless parameters, e.g., thermal conductivity ratio of solid to liquid, specific heat ratio of solid to liquid, and Biot number are represented.