A transfer coefficient-based structure parameters method for CFD simulation of bubbling fluidized beds

Abstract

An experimental and computational study was presented on the hydrodynamics of the bubbling fluidized bed (BFB). Based on the Eulerian–Eulerian two-fluid model, a new structure parameters model was validated with experimental results. Compared with the conventional structure parameters models with eight parameters, the new model uses fewer structure parameters to obtain good agreement with the experimental data, and reduces the difficulty in developing closure equations and solving for the parameters. It was found that five necessary structure parameters (εe, Use, fb, db and Usb) play an important role in the structure-based drag model, and they were sufficient to represent the heterogeneous structures of the BFB. The simulated radial and axial profiles of solid concentration were in reasonable agreements with the experimental data. Solid mixing, including gross circulation and local mixing, as well as the formation and motion of bubbles were simulated, indicating the feasibility of the combination of the new structure parameters model with the available structure-based drag model for simulating the bubbling fluidized bed.