MP-PIC simulation of circulating fluidized beds using an EMMS based drag model for Geldart B particles

作     者：Timo Dymala Tom Wytrwat Stefan Heinrich Timo Dymala;Tom Wytrwat;Stefan Heinrich

作者机构：Hamburg University of TechnologyInstitute of Solids Process Engineering and Particle TechnologyDenickestr.1521073 HamburgGermany 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2021年第19卷第6期

页      面：76-90页

核心收录：

学科分类：08[工学] 080103[工学-流体力学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：the financial support of the German Research Foundation(DFG) project number HE 4526/21-1. 

主　　题：3D-CFD simulation Circulating fluidized bed(CFB) Multiphase particle-in-cell method(MP-PIC) Energy minimizing multi-scale theory(EMMS) Validation study 

摘      要：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.