Owing to their simple structure, easy installation, low cost, and excellent thermal stratification, radial diffusers have been widely used in large-scale stratified thermal energy storage (TES) tanks. The current work proposes a novel nonequal-diameter radial diffuser. The short baffles for the top diffuser and bottom diffuser are above and below, respectively. On the one hand, the new diffuser design is beneficial to thermal stratification. On the other hand, it can reduce the cost of the radial diffuser. The thermal stratification and cost analysis of the proposed nonequal-diameter radial diffuser is performed based on the computational fluid dynamics. Moreover, the influence of the structural parameters on the diffuser performance is analyzed. The research results demonstrate that the nonequal-diameter radial diffuser has nearly the same thermal stratification performance as the equal-diameter radial diffuser and can significantly reduce the cost (37.5% when the diameter of the short baffle is 2/3 that of the long baffle). The thermal stratification performance of the stratified TES tank is optimized when the diameter ratio of the long baffle and the tank is 1/3, the diameter ratio of the short baffle and the long baffle is 1/3, and the distance between the two baffles is as small as possible. The research results are of considerable significance to the design, operation, and optimization of stratified TES tanks.

由于其结构简单，易于安装，成本低和出色的热分层性能，径向扩散器已被广泛用于大型分层热能存储（TES）储罐中。当前的工作提出了一种新颖的非等直径径向扩散器。顶部扩散器和底部扩散器的短挡板分别在上方和下方。一方面，新的扩散器设计有利于热分层。另一方面，它可以减少径向扩散器的成本。基于计算流体动力学，对所提出的非等径径向扩散器进行了热分层和成本分析。此外，分析了结构参数对扩压器性能的影响。研究结果表明，非等径径向扩散器具有与等径径向扩散器几乎相同的热分层性能，并且可以显着降低成本（当短挡板的直径为长挡板的2/3时，成本为37.5％）。 ）。当长挡板与水箱的直径比为1/3，短挡板与长挡板的直径比为1/3以及两个挡板之间的距离时，分层TES槽的热分层性能得以优化尽可能小。研究结果对分层TES储罐的设计，运行和优化具有重要意义。当短挡板的直径是长挡板的2/3时为5％）。当长挡板与水箱的直径比为1/3，短挡板与长挡板的直径比为1/3以及两个挡板之间的距离时，分层TES槽的热分层性能得以优化尽可能小。研究结果对分层TES储罐的设计，运行和优化具有重要意义。当短挡板的直径是长挡板的2/3时为5％）。当长挡板与水箱的直径比为1/3，短挡板与长挡板的直径比为1/3以及两个挡板之间的距离时，分层TES槽的热分层性能得以优化尽可能小。研究结果对分层TES储罐的设计，运行和优化具有重要意义。