Experimental Research on the Dense CFBs Riser and the Simulation Based on the EMMS Model
The flow structure in the CFB (circulating fluidized bed) riser has been investigated. Experimental studies were performed in a cold square section unit with 270mmx270mm><10m. Since the drag force model based on homogeneous two-phase flow such as the Gidaspow drag model could not depict the heterogeneous structures of the gas-solid flow, the structure-dependent energy-minimization multi-scale (EMMS) model based on the heterogenerity was applied in the paper and a revised drag force model based on the EMMS model was proposed. A 2D two-fluid model was used to simulate a bench-scale square cross-section riser of a cold CFB. The typical core-annulus structure and the back-mixing near the wall of the riser were observed and the assembly and fragmentation processes of clusters were captured. By comparing with the Gidaspow drag model, the results obtained by the revised drag model based on EMMS shows better consistency with the experimental data. The model can also depict the difference from the two exit configurations. This study once again proves the key role of drag force in CFD (Computational Fluid Dynamics) simulation and also shows the availability of the revised drag model to describe the gas-solid flow in CFB risers.
Gas-solid flow CFB EMMS drag force model
X.Y.Wang S.D.Wang B.G.Fan L.L.Liao F.Jiang X.Xu X.Z.Wu Y.H.Xiao
Key Laboratory of Advanced Energy and Power Technology, Institute of Engineering Thermophysics of Chinese Academy of Sciences, Beijing 100190
国际会议
西安
英文
258-263
2009-07-11（万方平台首次上网日期，不代表论文的发表时间）