bubble-based EMMS／PFB模型的建立及在加压流化床浓相段的应用  

Establishment of bubble-based EMMS/PFB model and its application on dense section of pressurized fluidized-bed

作　　者：宋素芳[1,2,3] 郝振华[1] 董立波[1] 李俊国[1] 房倚天[1] 

机构地区：[1]中国科学院山西煤炭化学研究所,煤转化国家重点实验室,山西太原030001 [2]太原科技大学化学与生物工程学院,山西太原030021 [3]中国科学院大学,北京100049

出　　处：《化工学报》2017年第8期2998-3005,共8页CIESC Journal

基　　金：国家自然科学基金项目(21606250);中国科学院青年创新促进会基金项目(2016162)~~

摘　　要：基于多尺度分解和能量消耗分析方法,结合压力下锥形分布板射流床气泡直径关联式,建立了一个适于加压流化床(PFB)的能量最小多尺度模型——bubble-based EMMS/PFB模型。应用此模型模拟一个二维加压射流床,分析了操作压力、位置高度、空隙率及剩余速度对非均匀因子的影响。通过模拟结果与实验数据的对比,发现该模型相比于Gidaspow模型,能够更准确地模拟加压射流床内颗粒浓度的分布状态及颗粒靠近壁面处的速度变化;将这种曳力模型应用到流化床浓相段的模拟,预测了床内颗粒浓度瞬时分布及沿轴向的时均值分布、颗粒的速度分布等流动行为,使流化床浓相段的气固流动行为可视化,对流化床的设计、放大有一定的指导作用。An energy minimization and multi-scale model, bubble-based EMMS/PFB, was established for pressurized fluidized-bed, based on methods of multi-scale decomposition and energy consumption analysis in combination with bubble diameter correlation to conical distributor. The model was used to simulate a 2D pressurized jetting fluidized-bed and to study influence of operating parameters such as operating pressure, bubble location, porosity and residual velocity on heterogeneous index. Comparison of simulation results to experimental data, it was showed that the new model provided better accuracy than the Gidaspow model in prediction of solid particle concentration distribution and change of particle velocity adjacent to wall above the distributor. Dense section simulation of a pressurized fluidized-bed by the new drag model yielded prediction of instantaneous and time-averaged axial distributions of particle concentration and particle velocity distribution. The simulation could make it available to visualize gas-solid flow behavior at dense section and provide guidance for design and industrial scale-up of pressurized fluidized-beds.

关 键 词：流化床 多尺度 数值模拟 气泡 两相流 流体动力学 

分 类 号：O359[理学—流体力学] TQ545[理学—力学]