加热方式对管壳式相变蓄热单元强化传热的可视化及数值模拟

为了提高相变蓄热系统在实际应用中的蓄热速率，本文建立了管壳式相变蓄热单元可视化实验平台，提出了一种外部加热法的强化传热方式，讨论了相变蓄热单元在外部加热法时的熔化特性和传热机理。通过Fluent软件模拟对比了外部加热法和内部加热法在熔化过程中的液相分数、熔化速率和均匀性等方面的差异。研究结果表明：外部加热法的使用能大幅提升蓄热单元的蓄热效率。与内部加热法相比，外部加热法在熔化过程中的传热和相变更加均匀。相比于内部加热法，由于外部加热法传热面积较大，熔化时间缩短了69.1%；在消除传热面积的影响后，外加热方法依靠广泛而强烈的自然对流使熔化时间减少了23.2%。

Visualization and numerical analysis of heat transfer enhancement in the shell and tube latent thermal energy storage unit by the heating method

In order to improve the heat storage rate of the latent thermal storage system in practical applications, an experimental platform for visualizing the thermal performance of the shell-and-tube latent thermal storage unit is established, an enhanced heat transfer method of the outside heating method is proposed, and the heat transfer mechanism of the outside heating method in the melting process is discussed. The differences between the outside heating method and the inside heating method in terms of liquid fraction and homogeneity are also analyzed by simulation comparison. The results show that the outside heating method has more uniform heat transfer in the melting process compared with the inside heating method. The outside heating method reduces the melting time by 69.1% due to the larger heat transfer area; after eliminating the effect of heat transfer surface, the outside heating method relies on extensive and strong natural convection to reduce the melting time by 23.2%.