Important Analysis of Liquid Vaporization Modeling Scheme in Computational Fluid Dynamics Modeling of Gas–Liquid–Solid Polyethylene Fluidized Bed Reactors
Important Analysis of Liquid Vaporization Modeling Scheme in Computational Fluid Dynamics Modeling of Gas–Liquid–Solid Polyethylene Fluidized Bed Reactors
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DOI：
10.1021/acs.iecr.7b02912
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发表时间：
2017-09
影响因子：
4.2
通讯作者：
Hui Pan;X. Liang;Litao Zhu;Zheng‐Hong Luo
中科院分区：
文献类型：
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作者：
Hui Pan;X. Liang;Litao Zhu;Zheng‐Hong Luo
采用改进的三流体计算流体力学模型，对聚乙烯工业床冷凝模式下的三相体系进行了数值模拟。将该模型与描述液体蒸发的传热模型、液滴蒸发模型和颗粒平衡模型相结合，建立了描述液体蒸发的模型。数值结果表明，液体汽化影响气速分布，进而影响流动结构。随着冷凝液含量的增加，床底床层温度梯度增大，床层整体温度降低。汽化速率随液滴Sauter平均直径增大而增大。因此，液体蒸发对液滴直径的影响很敏感。
A developed three-fluid computational fluid dynamics model was used to investigate the three-phase system in a polyethylene industrial fluidized bed in condensed mode. This model was incorporated with a liquid vaporization modeling scheme comprising heat transfer model, droplet vaporization model, and population balance model to describe liquid evaporation. Numerical results demonstrate that liquid vaporization affects gas velocity distribution, thereby influencing the flow structure. With increasing condensed-liquid contents, the bed temperature gradient at the bed bottom increases and the overall bed temperature decreases. The vaporization rate increases with increasing droplet Sauter mean diameter. Hence, the influence of liquid vaporization is sensitive to droplet diameter.