倒置液固喷动床流动特性的数值模拟研究

发布时间：2018-02-10 17:31

本文关键词： 倒置喷动床液固两相流数值模拟双流体模型　出处：《东北石油大学》2016年硕士论文　论文类型：学位论文

【摘要】：由于液固喷动床具有传热,传质性能好,混合均匀,结构简单等优点,被广泛应用于石油污水和工业废水处理等领域。随着科技的不断进步,流态化技术越来越先进,本文应用一种新型的倒置液固喷动床对颗粒密度小于液体密度的反流态化系统进行模拟研究,为倒置床在污水处理领域的应用提供理论依据。本文对三维倒置喷动床内液固相流动特性进行数值模拟,基于欧拉-欧拉双流体模型结合颗粒动理学研究液固两相流动,采用k-?湍流模型对液相流动进行求解,应用Gidaspow曳力模型模拟液固相相间作用力。入口表观液速分别为0.35m/s,0.18m/s和0.09m/s,液体粘度分别为0.001 Pa·s,0.00432 Pa·s和0.00786 Pa·s,颗粒直径分别为1.41mm和2mm时,床内两相流流动行为的变化情况,同时对入口扩张锥角分别为90°和60°的倒置液固喷动床内颗粒的流动特性进行对比分析。研究结果表明:颗粒在倒置喷动床入口液体的冲击下,在中心附近向下运动,到达床层附近后向两侧边壁运动,到达边壁后再向上运动。倒置喷动床的入口锥角越小,颗粒的运移速度越大,床层厚度越大。液相粘度越大,床层厚度越大,颗粒速度越小。随着入口表观液速的增大,颗粒相和液相的轴向速度都随之增大。颗粒温度随着颗粒体积分数的增加先增大后减小,且入口液速越大,液相粘度越小,颗粒温度越大。
[Abstract]:Liquid solid spouted bed has the advantages of heat transfer, good mass transfer, uniform mixing and simple structure. It has been widely used in petroleum wastewater and industrial wastewater treatment and other fields. With the development of science and technology, fluidization technology is becoming more and more advanced. In this paper, a new inverted liquid-solid spouted bed is used to simulate the reverse fluidization system in which the particle density is less than the liquid density. In this paper, numerical simulation of liquid-solid flow characteristics in three-dimensional inverted spouted bed is carried out. Based on Euler-Euler two-fluid model and particle kinetic study, liquid-solid two-phase flow is studied by k-? The Gidaspow drag model is used to simulate the interaction between liquid and solid phase. The apparent liquid velocity is 0.35 m / s / s 0.18 m / s and 0.09 m / s, respectively. The viscosity of the liquid is 0.00432 Pa 路s and 0.00786 Pa 路s, and the particle diameter is 1.41mm and 2mm, respectively. The flow behavior of two-phase flow in the bed is changed, and the flow characteristics of the particles in the inverted liquid-solid spouted bed with the inlet expansion cone angles of 90 掳and 60 掳respectively are analyzed. The results show that the particles are impacted by the inlet liquid of the inverted spouted bed. The lower the inlet cone angle of the inverted spouted bed is, the greater the moving velocity of particles is, the greater the bed thickness is, and the greater the liquid viscosity is, the lower the inlet cone angle of the inverted spouted bed is, the larger the bed thickness is. The larger the bed thickness, the smaller the particle velocity. With the increase of the apparent liquid velocity at the inlet, the axial velocity of both the particle phase and the liquid phase increases. The particle temperature increases first and then decreases with the increase of particle volume fraction, and the velocity of the inlet liquid increases. The lower the liquid viscosity, the higher the particle temperature.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X703

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