Modeling and simulation of particle size distribution behavior in gas-liquid-solid polyethylene fluidized bed reactors
Modeling and simulation of particle size distribution behavior in gas-liquid-solid polyethylene fluidized bed reactors
复制标题
气-液-固聚乙烯流化床反应器中粒度分布行为的建模和仿真
DOI：
10.1016/j.powtec.2018.01.014
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发表时间：
2018-04-01
影响因子：
5.2
通讯作者：
Luo, Zheng-Hong
中科院分区：
文献类型：
--
作者：
Pan, Hui;Liu, Qi;Luo, Zheng-Hong
本文将描述颗粒尺寸分布（PSD）的粒子数平衡模型（PBM）和描述液体蒸发的液体蒸发模型（VMS）（包括传热模型和液滴蒸发模型）结合到三流体计算流体力学（CFD）模型中，对工业规模的气液固三相聚乙烯流化床反应器（FBR）中的PSD行为进行了分析。通过与工业数据和计算数据的比较，验证了该耦合模型的有效性，并讨论了颗粒动力学、节点数和冷凝液含量对PSD行为的影响。与气固聚乙烯常规流化床反应器不同，尽管PSD行为主要受颗粒团聚的影响，但颗粒破碎动力学对PSD影响很大，尤其是在聚合初期，颗粒破碎动力学与团聚体竞争，降低了反应器的反流化风险。此外，节点的数量强烈影响PSD的仿真结果，并使用三个节点是最好的配置。在该三相体系中，冷凝液含量的增加提高了颗粒生长速率，这影响了反应器的生产率和产物的性质，例如平均粒径和最终PSD。(C)2018爱思唯尔B.V.保留所有权利。
In this work, population balance model (PBM) that describes particle size distribution (PSD) and liquid vaporization modeling scheme (VMS) (including the heat transfer model and droplet vaporization model), which describes liquid evaporation, were incorporated into a three-fluid computational fluid dynamics (CFD) model to analyze PSD behavior in an industrial-scale gas-liquid-solid three-phase polyethylene fluidized bed reactor (FBR). The validation of this CFD-VMS-PBM coupled model was conducted through comparing results with industrial and calculated data, which then was applied to discuss the characteristics of PSD behavior in terms of the effects of particle kinetics, node number, and condensed liquid content. Unlike gas-solid polyethylene conventional FBRs, although the PSD behavior was dominated by particle agglomeration, particle breakage kinetics exerted a great impact on PSD, especially at the initial polymerization period when it competed with aggregates to decrease the defluidization risk of the reactor. Furthermore, the number of nodes strongly affected PSD simulation results, and using three nodes was the best configuration. In this three-phase system, the increase in the condensed liquid content improved the particle growth rate, which affected the reactor's productivity and product's properties, such as mean particle size and final PSD. (C) 2018 Elsevier B.V. All rights reserved.