中文摘要：

对不同提升管出口结构的高密度循环流化床全场气固流动进行三维数值模拟,气相采用LES湍流模型,固相采用MP-PIC方法。系统地考察了五种不同的提升管出口条件对固体循环通量、系统压力分布和颗粒浓度和速度分布的影响。结果表明,出口结构对提升管出口处的固体循环通量、出口局部压损和出口附近颗粒浓度分布均有明显影响;与其余四种出口条件相比,采用C型光滑出口,可以使循环流化床获得更高的固体循环通量和提升管颗粒浓度;在单侧出口条件下,高通量提升管颗粒浓度呈现径向非对称分布,颗粒速度径向分布在出口附近也有明显减小。

英文摘要：

Three-dimensional（3-D） simulations have been developed to simulate the flow behaviors in a full-loop high-density circulating fluidized bed with different riser exit geometry.The Large Eddy Simulation（LES） turbulence model is used for gas phase,and the multiphase particle-in-cell（MP-PIC） model is used for solid phase.The in uences of five different riser exit geometries upon the solid mass flux,pressure distribution,the particle concentration and velocity distribution were systematically investigated.It is shown that（i） the type of exit has a significant effect on solid mass flux,local pressure loss and particle concentration;（ii） compared with the rest of the four kinds of exit,the use of type C smooth exit results in the higher solid mass flux and particle concentration in the circulating fluidized bed;（iii） pronounced asymmetry can be found in radial distribution of solids concentration in the high flux riser with asymmetric exit,the time-averaged solids concentration at the exit side was larger than the opposite side.