摘要
采用基于颗粒动力学的双流体模型对FCC颗粒湍动床和挡板床内气固流动进行模拟研究,考察颗粒相壁面边界条件对其气固流动的影响。研究结果表明,采用Johnson-Jackson壁面边界条件描述壁面与颗粒的相互作用时,壁面反射系数对气固流动行为影响较大,而颗粒-壁面碰撞恢复系数影响甚微。通过将模拟结果与实验数据对比,确定壁面反射系数取0.001时能较好地描述壁面与颗粒间的作用力。对于挡板床,挡板的加入增大了壁面面积,壁面对颗粒的作用力更加显著,挡板壁面采用部分滑移条件时,穿过导向挡板向上和向下运动的颗粒数量均较大于采用无滑移条件时的结果。挡板壁面的光滑程度对其在床层中的作用有一定影响。
The two-fluid model incorporating granular kinetic theory was applied to simulate the gas-solid flow in FCC particles turbulent bed, and to investigate the effect of solid phase wall boundary condition on the predicted gas-solid flow behavior. The results showed that when the Johnson-Jackson boundary condition was used to describe the interaction between wall and particles, the specularity coefficient had a pronounced influence on flow behavior, while the particle-wall restitution coefficient played a minor role. The comparison of simulated results with experimental data indicated that the specularity coefficient of 0.001 was opportune to describe the interaction between wall and particles. For the turbulent fluidization bed with baffles, the introduction of baffles increased the wall area, leading to a strong interaction between wall and particles. When the partial-slip wall condition was used to deal with the wall of baffles, the predicted quantity of particles which passed through the baffles was more than that when the no-slip wall condition was used. The characteristic of baffles wall had some impact on its role played in fluidization beds.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2014年第1期57-62,共6页
Chemical Reaction Engineering and Technology
基金
国家重点基础研究发展计划(973计划)(2012CB215000)
国家自然科学基金(91334104)
关键词
湍动流化床
气固流动
壁面边界条件
数值模拟
turbulent fluidization bed
gas-solid flow
wall boundary condition
numerical simulation
