摘要
采用计算流体力学-离散单元-有限元(CFD-DEM-FEM)耦合方法对一种新型过程强化技术—新型静态旋转流化床(RFB-SG)内的气固运动行为进行了数值模拟研究,将FEM与DEM耦合处理颗粒与床体复杂边界的相互作用.流化气体沿与床体径向呈60°夹角吹入流化床,对颗粒产生切向和径向曳力流化床内颗粒.考察了3种不同的入口气速对流化床内气固流动行为的影响,得到了床内的气固流动形态、固含率分布及床层压降分布.结果表明,3种气速都可使流化床得到很好的流化,随着入口气速的增大,颗粒床层厚度逐渐收缩,趋向于在流化床外周形成致密薄床层,床层压降逐渐增大,波动更加剧烈,局部压降的不均匀性加重.
Numerical modeling of the hydrodynamics in a novel rotating fluidized bed in a static geometry(RFB-SG),a proposed process intensification technology,was conducted at different gas inlet velocities.The motion of particles in RFB-SG with complex geometry was solved by combining DEM and finite element method.The fluidization gas was injected into fluidization chamber via multiple gas inlet slots in the outer cylindrical wall at a radial separation angel of 60°.The flow pattern at different gas inlet velocities,solids volume fraction distribution and bed pressure drop in RFB-SG were obtained,and the effects of gas inlet velocity on gas-solids two-phase flow were investigated.In the RFB-SG simulated,solids were fluidized at all three different gas inlet velocities.At low gas inlet velocity,the particles tended to form a less dense bubbling fluidized bed that was both tangentially and radially fluidized.At relatively high gas inlet velocity,the particles tended to form a denser thin bed toward the outer fluidization chamber,i.e.reversed bed expansion occurred,and its behavior was mainly characterized by tangential fluidization.With increase of the gas inlet velocity,the accumulation phenomenon of particles and non-uniform of bed pressure drop became more and more serious,which was bad for fluidization,but the stable fluctuation of the bed pressure drop became more violent,which was good for fluidization.
出处
《过程工程学报》
CAS
CSCD
北大核心
2009年第S2期175-179,共5页
The Chinese Journal of Process Engineering
基金
国家973计划资助项目(编号:2007CB209706)
浙江大学优秀青年教师资助计划
关键词
过程强化
静态旋转流化床
离散单元法
计算流体力学
有限单元法
process intensification
rotating fluidized bed
discrete element method
computational fluid dynamics
finite element method
