3D Numerical Prediction of Gas-Solid Flow Behavior in CFB Risers for Geldart A and B Particles

Ali Özel, Pascal Fede, Olivier Simonin

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In this study, mono-disperse flows in squared risers conducted with A and B-type particles were simulated by Eulerian n-fluid 3D unsteady code. Two transport equations developed in the frame of kinetic theory of granular media supplemented by the interstitial fluid effect and the interaction with the turbulence (Balzer et al., 1996) are resolved to model the effect of velocity fluctuations and inter-particle collisions on the dispersed phase hydrodynamic. The studied flow geometries are three-dimensional vertical cold channels excluding cyclone, tampon and returning pipe of a typical circulating fluidized bed. For both type of particles, parametric studies were carried out to determine influences of boundary conditions, physical parameters and turbulence modeling. The grid dependency was analyzed with mesh refinement in horizontal and axial directions. For B-type particles, the results are in good qualitative agreement with the experiments and numerical predictions are slightly improved by the mesh refinement. On the contrary, the simulations with A-type particles show a less satisfactory agreement with available measurements and are highly sensitive to mesh refinement. Further studies are carried out to improve the A-type particles by modeling subgrid-scale effects in the frame of large-eddy simulation approach.
Original languageEnglish
Title of host publicationProceedings of the 20th International Conference on Fluidized Bed Combustion
PublisherSpringer
Pages805-811
Number of pages7
ISBN (Electronic)9783642026829
ISBN (Print)9783642026812
DOIs
Publication statusPublished - 2009

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Özel, A., Fede, P., & Simonin, O. (2009). 3D Numerical Prediction of Gas-Solid Flow Behavior in CFB Risers for Geldart A and B Particles. In Proceedings of the 20th International Conference on Fluidized Bed Combustion (pp. 805-811). Springer. https://doi.org/10.1007/978-3-642-02682-9_124