Steady-state simulation of core-annulus flow in a circulating fluidized bed (CFB) riser

A steady-state multiphase CFD model is proposed for the simulation of core-annulus flow in a circulating fluidized bed (CFB) riser. A CFD model based on Eulerian–Eulerian approach is developed, which incorporates two mechanisms that result in the lateral profiles of solids: mixing of individual particles based on a kinetic theory treatment and mixing of clusters based on a modified k−εk−ε turbulence model. The steady-state model can simulate the core-annulus flow more efficiently, which can eliminate the unrealistic sensitivity and need less computational resources comparing with other transient models. This model shows more potential for the simulation of commercial fluidized equipments. The sensitivity of the model predictions involving four parameters indicates that ewew and φφ have weak influence on the correctly prediction of core-annulus flow, while the model remains a certain of sensitivity to eses and CsCs. The results predicted by the model show good agreement with experimental data under different operating conditions reported by Tartan and Gidaspow (2004).

► A steady-state model is proposed for the simulation of core-annulus flow in a CFB riser.
► Two mechanisms cause the lateral profiles of solids.
► The steady-state model eliminates the unrealistic sensitivity.
► The model shows greater potential for the simulation of commercial fluidized equipments.