【摘要】 建立了单喷管鼓泡流化床欧拉-欧拉双流体模型,分别采用标准k-ε湍流模型、RNG k-ε湍流模型和Realizable k-ε模型对平板、斜板和U形板流化床进行数值模拟计算.结果表明,标准k-ε模型和RNG k-ε模型模拟计算结果与实验结果吻合较好.床层固体颗粒浓度分布呈以下规律:在气体主要流经的中心区域颗粒浓度较低,而在靠近壁面区域颗粒浓度相对较高.3种分布板结构流化床中心区域颗粒轴向速度为正值并且较大,颗粒向上运动;靠近壁面附近区域颗粒轴向速度为负值,做下降运动,产生了"环-核"流动现象.与平板流化床相比,斜板和U形板流化床的横向运动速度更大,容易形成循环运动.更多还原

【Abstract】 An Euler-Euler two-fluid model for single nozzle bubbling fluidized bed was established,and numerical simulations for fluidized beds with flat plate,inclined plate and U-shaped plate were conducted using standard k-εmodel,RNG k-ε model and Realizable k-ε model,respectively.The results show that the numerical simulation results by standard k-ε model and RNG k-ε model agreed well with the experimental results.The distribution regularity of solid particle concentration in beds was as follows:the particle concentration in the central area where most of the gas flowed through was low,while that in the areas close to the walls was relatively high.For the three distribution plates in the study,the particles in the center had a positive velocity and moved upwards,while those close to the walls had a negative velocity and moved downwards,thus resulting in the "ring-core" flow phenomena.Compared with the flat bed,the lateral velocity for inclined plate and U-shaped plate fluidized beds was higher,which was more likely to generate circular motion.更多还原