Numerical study on the influence of various physical parameters over the gas-solid two-phase flow in the 2D riser of a circulating fluidized bed

被引:54
作者
Cabezas-Gómez, L [1 ]
Milioli, FE [1 ]
机构
[1] Univ Sao Paulo, Sch Engn Sao Carlos, BR-13566590 Sao Carlos, SP, Brazil
基金
巴西圣保罗研究基金会;
关键词
solid phase viscosity; CFB; Eulerian simulation; gas-solid two-phase flow;
D O I
10.1016/S0032-5910(03)00071-8
中图分类号
TQ [化学工业];
学科分类号
0817 ;
摘要
A numerical parametric study was performed on the influence of various physical aspects over the hydrodynamics of gas-solid two-phase flow in the riser of a circulating fluidized bed (CFB). The addressed features were the solid phase viscosity, the gas-solid interface momentum transfer correlations, and the coordinate system. An Eulerian continuum formulation was applied for both phases. The resulting two-fluid model and numerical procedure followed a version of the MICEFLOW code. The simulation results are compared to available experimental data. The effects of the concerning features on the flow behavior are shown, mainly regarding cluster evolution. The flow frequency fluctuations typical to CFB risers were observed. It was also observed that for high values of solid phase viscosity there is an accumulation of solids near the outlet forming large clusters. When those clusters fall down, the instantaneous cross-sectional average solid mass velocity becomes negative. For inviscid solid phase, no cluster formation is observed. The results show the incorrectness of assuming symmetry boundary condition at the axis of the riser when cylindrical coordinates are used. Quite different results were obtained for different correlations for gas-solid interface momentum transfer. Finally, a comparison is presented of predictions from the Illinois Institute of Technology (IIT) hydrodynamic models A and B. (C) 2003 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:216 / 225
页数:10
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