The present study aims to fill the knowledge gap in the partially heated energy storage process by finding the optimal heat source location. A new simplified enthalpy based lattice Boltzmann method is proposed for the present work. The new model follows the predictor–corrector step, while the traditional model follows the collision-streaming step. Compared to the traditional model, this new model has the same accuracy, but it has advantages on virtual memory saving and physical boundary treatment due to its unique structure. Besides, in the partially heated energy storage process, the heat source location can pose significant impact on the charging efficiency and the energy storage rate. The optimal heat source location is where the maximum charging efficiency and energy storage rate are achieved. Results indicate that, a small region with the length of 0.1 l can be deemed as the optimal region for the heat source location, for that the charging time and the energy storage rate at various locations inside that region are almost the same. The optimal region decreases with the increase of Rayleigh and Prandtl numbers. In addition, the optimal regions for some specific heat source lengths and Rayleigh numbers are obtained. Based on these results, a map is provided to indicate the variations of the optimal region. According to this map, the optimal heat source locations for more varied conditions can be estimated through the heat source length and the Rayleigh number, which would be quite useful and significant for the thermal design in various engineering applications.

本研究旨在通过找到最佳的热源位置来填补部分加热的能量存储过程中的知识空白。提出了一种新的基于简化焓的格子玻尔兹曼方法。新模型遵循预测器-校正器步骤，而传统模型遵循碰撞流步骤。与传统模型相比，该新模型具有相同的精度，但由于其独特的结构在虚拟内存节省和物理边界处理方面具有优势。此外，在部分加热的能量存储过程中，热源的位置会对充电效率和能量存储速率产生重大影响。最佳的热源位置是实现最大充电效率和能量存储率的位置。结果表明， 可以将l视为热源位置的最佳区域，因为该区域内部各个位置的充电时间和能量存储率几乎相同。最佳区域随着瑞利和普朗特数的增加而减小。另外，获得了一些特定热源长度和瑞利数的最佳区域。基于这些结果，提供了一个地图以指示最佳区域的变化。根据该图，可以通过热源长度和瑞利数来估计用于更多变化条件的最佳热源位置，这对于各种工程应用中的热设计将是非常有用且有意义的。