Options
MP-PIC simulation of circulating fluidized beds using an EMMS based drag model for Geldart B particles
Publikationstyp
Journal Article
Date Issued
2021-12
Sprache
English
Author(s)
Journal
Volume
59
Start Page
76
End Page
90
Citation
Particuology 59: 76-90 (2021-12)
Publisher DOI
Scopus ID
In this study the multiphase particle-in-cell (MP-PIC) method is used for the simulation of two pilot-scale circulating fluidized beds (CFBs) with quartz sand belonging to Geldart's group B as bed material. The simulations were performed using a homogeneous drag model as well as a structure dependent drag model based on the energy minimization multi-scale method (EMMS). The results are compared with experimental data from literature as well as experiments. The simulations with the EMMS based drag model show a good agreement of the time-averaged axial solids concentration, circulation rate and riser pressure drop. Furthermore, a lower grid sensitivity is observed compared to the homogeneous drag model. In contrast to the conventional drag model a dense bottom zone is predicted by the EMMS based drag model. An overprediction of the solid concentration in the dense bottom zone is presumably due to an overprediction of the cluster diameter that is calculated using an empirical cluster diameter correlation. This shows the necessity for a new meso-scale cluster correlation for the simulation of Geldart B particles. Furthermore, the results of the time-averaged radial solids concentration differ from the expectations of a core-annulus flow indicating that a mesh refinement at the walls is necessary. Finally, the importance of using a realistic particle size distribution is identified.
Subjects
3D-CFD simulation
Circulating fluidized bed (CFB)
Energy minimizing multi-scale theory (EMMS)
Multiphase particle-in-cell method (MP-PIC)
Validation study