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乙烯气相聚合流化床反应器广泛用于聚乙烯的生产,针对该体系建立了计算流体力学模型,用以分析流化床内的流动特性。文章进行了灵敏度分析,确定网格数量为53732能够满足计算需求,并且比较了Wen&Yu模型和Gidaspow模型2种曳力模型的计算结果,从床层膨胀比和床层压降上确定采用Wen&Yu模型更加适合该体系。将模拟得到的床层膨胀比、床层压降和临界流化速度3个参数与经验公式计算值继续比较,二者吻合,所建模型为后续流化床流动特性的研究打下良好的基础。
Ethylene gas-phase polymerization fluidized bed reactor is widely used in the production of polyethylene. A computational fluid dynamics model is established for the system to analyze the flow characteristics in a fluidized bed. The sensitivity analysis of the paper is carried out. The number of grids is 53732, which can meet the calculation requirements. The calculation results of two drag-drag models of Wen & Yu model and Gidaspow model are compared. The Wen & Yu model is more determined from the bed expansion ratio and bed pressure drop Suitable for the system The simulation results of bed expansion ratio, bed pressure drop and critical fluidization velocity are compared with those of empirical formula. The results agree well with each other. The model can lay a good foundation for the subsequent study of fluidized bed flow characteristics.