Investigation on the effective thermal conductivity of carbonate salt based composite phase change materials for medium and high temperature thermal energy storage
Investigation on the effective thermal conductivity of carbonate salt based composite phase change materials for medium and high temperature thermal energy storage
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DOI：
10.1016/j.energy.2019.04.029
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发表时间：
2019-06
期刊：
影响因子：
9
通讯作者：
Chuan Li;Qi Li;Yulong Ding
中科院分区：
文献类型：
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作者：
Chuan Li;Qi Li;Yulong Ding
本文研究碳酸盐基复合相变材料（CPCM）的有效导热系数。此类材料通常由碳酸盐作为相变材料（PCM）、MgO作为陶瓷骨架材料（CSM）和石墨片作为导热增强材料（TCEM）组成，主要用于中高温储热应用。制备并研究了两种碳酸盐基CPCM，其中一种是NaLiCO3，另一种是Na2CO3。提出了基于微观结构特征的理论模型来预测复合材料的有效导热率。该模型使用一个晶胞，该晶胞被建模为两个 MgO 球体，与填充在它们的颗粒间空隙中的 PCM 和 TCEM 混合物接触。文献中报道的两个模型用于确定颗粒之间的热阻并估计烧结颈参数。构建了基于平行板的实验装置来测量复合材料的有效导热率。将模型结果与实验数据进行比较，得到合理的一致性。还对有效导热系数预测的各种文献模型进行了相互比较和实验数据。
This paper concerns the effective thermal conductivity of carbonate salt based composite phase change materials (CPCMs). Such materials typically consist of a carbonate salt as the phase change material (PCM), an MgO as the ceramic skeleton material (CSM) and a graphite flake as the thermal conductivity enhancement material (TCEM), and are mainly used for medium and high temperature thermal energy storage applications. Two carbonate salt based CPCMs are prepared and studied with one being NaLiCO3and the other Na2CO3. A theoretical model based on the microstructure characteristics is proposed to predict the effective thermal conductivity of the composites. The model uses a unit cell modelled as two MgO spheres in contact with the PCM and TCEM mixture filled in the interparticle void of them. Two models reported in the literature are employed to determine the thermal resistance between the particles and to estimate the sintered neck parameters. A parallel-plate based experimental set up is constructed to measure the effective thermal conductivity of the composites. The modelling results are compared with experimental data and reasonably agreements are obtained. Various literature models for the effective thermal conductivity predication are also compared with each other and experimental data.