Mesoscopic exploration on mass transfer in porous thermochemical heat storage materials
Mesoscopic exploration on mass transfer in porous thermochemical heat storage materials
复制标题
多孔热化学储热材料传质细观探索
DOI：
10.1016/j.ijheatmasstransfer.2019.01.108
复制
发表时间：
2019-06
影响因子：
5.2
通讯作者：
Zhao C Y
中科院分区：
文献类型：
--
作者：
Xia B Q;Pan Z H;Yan J;Zhao C Y
在热化学储热系统中，多孔材料的传质特性是影响其充放热性能的关键因素。因此，需要一种算法来模拟蓄热材料内的传输过程，并准确地计算有效扩散系数。本文研究的是广泛应用于CaO-Ca（OH）2或CaO-CaCO 3蓄热体系的多孔氧化钙。本文采用随机游走法对分形多孔介质进行了重构，得到了与真实的蓄热材料相似的分形多孔介质。在此基础上，采用格子Boltzmann方法模拟了分形多孔介质中气体通过复杂多孔微结构的扩散过程。结果表明，热化学蓄热材料具有很强的分形特征，分形维数越大，材料的扩散阻力越大。CaO和Ca（OH）2的有效气体扩散系数分别为0.228和0.188。此外，研究发现，在较高温度下制备的氧化钙样品由于气体扩散较差而具有较差的放热性能。此外，有效扩散系数和多孔材料的孔隙率之间的相关性进行了数值预测和评估。本文提出的分形模型-LBM法可作为一种简便估算有效扩散系数和传质系数的有力工具。
Mass transfer is the key characteristic that affects the charging and discharging performance of the porous materials used in thermochemical heat storage systems. Therefore, an algorithm is required to simulate the transport process within heat storage materials and to accurately evaluate the effective diffusion coefficient. This study is about porous calcium oxide, which is widely used in CaO-Ca(OH)2or CaO-CaCO3heat storage systems. In this paper, the fractal porous media that resemble real heat storage materials are reconstructed by a random walk method. Furthermore, the gas diffusion process through complicated porous microstructures within fractal porous media is simulated by an efficient lattice Boltzmann method. Results indicate that thermochemical heat storage materials have great fractal characteristic and materials with larger fractal dimension have more diffusion resistance. The effective gas diffusion coefficients of CaO and Ca(OH)2are obtained from the ratios of effective gas diffusion coefficient and bulk gas diffusion coefficient that are 0.228 and 0.188 for CaO and Ca(OH)2, respectively. Additionally, it is found that calcium oxide samples prepared at higher temperatures have the poorer exothermic performance because of the poorer gas diffusion. Moreover, the correlation between the effective diffusion coefficients and the porosity of porous materials is numerically predicted and evaluated. The fractal model-LBM method developed in this paper may serve as a great tool for easy estimation of effective diffusion coefficients and mass transfer.
登录
查看更多内容
影响因子：
4.6
作者：
Zou, QS;He, XY
通讯作者：
He, XY
影响因子：
2.6
作者：
Deqiang Mu;Zhong‐sheng Liu;Cheng Huang;N. Djilali
通讯作者：
Deqiang Mu;Zhong‐sheng Liu;Cheng Huang;N. Djilali
影响因子：
6.7
作者：
K. Bataineh;A. Gharaibeh
通讯作者：
K. Bataineh;A. Gharaibeh
影响因子：
1.9
作者：
Zhanggang Liang;R. He;Qun Chen;Xuchang Xu;J. Sato
通讯作者：
Zhanggang Liang;R. He;Qun Chen;Xuchang Xu;J. Sato
DOI：
10.1103/physreve.75.036702
发表时间：
2007-03
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
Moran Wang;Jinku Wang;N. Pan;Shiyi Chen
通讯作者：
Moran Wang;Jinku Wang;N. Pan;Shiyi Chen