Abstract

The immersion of a heat exchanger into a fluidized bed changes the hydrodynamic structure of the bed, which, according to this study, has a decisive influence on the heat transfer process. A near-surface zone with a local vertical circulation of particles and a porosity that is higher than that in the rest of the bed volume is formed near the immersed body with an increase in the velocity of the gas blown through the bed. As is shown in this study, the deterioration of the exchange of particles between this zone and the rest of the bed volume leads to a decrease in the intensity of external heat transfer with an increase in the gas velocity. A model is proposed that makes it possible to calculate the width of the near-surface zone and the time of residence of fluidized bed particles in it.

中文翻译：

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流化床中热交换表面附近颗粒运动的分析和模拟

摘要

将换热器浸入流化床中会改变床的流体力学结构，根据这项研究，它对传热过程具有决定性的影响。在沉浸体附近形成近表面区域，该区域具有颗粒的局部垂直循环并且孔隙率高于床其余部分中的孔隙率，并且通过床吹入的气体的速度增加。如本研究所示，该区域与其余床层之间的颗粒交换变差，导致外部传热强度降低，同时气体流速增加。提出了一个模型，该模型可以计算近表面区域的宽度和流化床颗粒在其中的停留时间。