Young Researchers and Elite Club, Yasooj Branch, Islamic Azad University, Yasooj, Iran.
College of Information Sciences and Technology (IST), Data Science and Artificial Intelligence Program, Penn State University, State College, Pennsylvania, PA, United States of America.
PLoS One. 2021 Mar 24;16(3):e0246972. doi: 10.1371/journal.pone.0246972. eCollection 2021.
In the present study, the thermal energy storage of a hot petal tube inside a shell-tube type Thermal Energy Storage (TES) unit was addressed. The shell is filled with the capric acid Phase Change Material (PCM) and absorbs the heat from a hot U-tube petal. The governing equations for the natural convection flow of molten PCM and phase change heat transfer were introduced by using the enthalpy-porosity approach. An automatic adaptive mesh scheme was used to track the melting interface. The accuracy and convergence of numerical computations were also controlled by a free step Backward Differentiation Formula. The modeling results were compared with previous experimental data. It was found that the present adaptive mesh approach can adequately the melting heat transfer, and an excellent agreement was found with available literature. The effect of geometrical designs of the petal tube was investigated on the melting response of the thermal energy storage unit. The phase change behavior was analyzed by using temperature distribution contours. The results showed that petal tubes could notably increase the melting rate in the TES unit compared to a typical circular tube. Besides, the more the petal numbers, the better the heat transfer. Using a petal tube could increase the charging power by 44% compared to a circular tube. The placement angle of the tubes is another important design factor which should be selected carefully. For instance, vertical placement of tubes could improve the charging power by 300% compared to a case with the tubes' horizontal placement.
在本研究中，研究了壳管式热能存储（TES）单元内热花瓣管的热能存储。壳体内填充了癸酸相变材料（PCM），并从热 U 形花瓣管吸收热量。通过焓-孔隙方法引入了熔融 PCM 的自然对流流动和相变传热的控制方程。采用自动自适应网格方案来跟踪熔化界面。数值计算的准确性和收敛性也通过自由步向后差分公式进行控制。将建模结果与以前的实验数据进行了比较。结果表明，目前的自适应网格方法可以充分模拟熔化传热，与现有文献吻合较好。研究了花瓣管的几何设计对热能存储单元熔化响应的影响。通过温度分布轮廓图分析了相变行为。结果表明，与典型的圆形管相比，花瓣管可以显著提高 TES 单元中的熔化速率。此外，花瓣管的数量越多，传热效果越好。与圆形管相比，使用花瓣管可以将充电功率提高 44%。管的放置角度是另一个重要的设计因素，应仔细选择。例如，与管水平放置的情况相比，垂直放置管可以将充电功率提高 300%。
