基于EMMS模型的聚乙烯流化床流体力学模拟

EMMS-based simulation on the hydrodynamics in polyethylene fluidized bed reactor

目前,针对气-固流化床的数值模拟多采用欧拉-欧拉双流体模型(TFM)。而传统的TFM基于均匀拟流体假设,不能准确描述流化床内流态化的非均匀性及介观尺度的性质,如颗粒团聚。本文采用基于能量最小多尺度方法(EMMS)的双流体模型(EFM)来研究聚乙烯流化床流体动力学,模拟结果证明EFM较好把握了流化床内的非均匀性以及介观尺度性质,更能准确描述聚乙烯流化床反应器内部的流体动力学。EFM模型的应用可以为聚乙烯生产过程中流化床结构改进以及"热点"的避免提供更有说服力的模拟验证。

Currently, most numerical simulations of gas-solid FBR adopt Euler-Euler two-fluid model （TFM）. But TFM based on the assumption of structural homogeneity results in an incorrect prediction of the properties of heterogeneity and the meso-scale, such as clusters. This paper proposes a special TFM called EFM which based on energy-minimization multi-scale model （EMMS） to study the hydrodynamic of heterogeneous flows in PE FBR. The simulation data reveal that EFM has better performance in the description of the hydrodynamics in PE FBR. Taking advantage of the EFM approach we could provide more convincing simulation results for the structure improvement and the preventing of＂hot spots＂ formation in PE FBR.