流化超细颗粒相间作用与颗粒动理学的研究

项目名称： 流化超细颗粒相间作用与颗粒动理学的研究

项目编号： No.21276056

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 化学工业

项目作者： 陆慧林

作者单位： 哈尔滨工业大学

项目金额： 80万元

中文摘要： 本项目将以气体-超细颗粒两相流态化过程为研究对象，以稠密气体分子运动论为基础，建立超细颗粒碰撞动力学，研究超细颗粒相互作用规律。基于矩量法，建立超细颗粒团聚粒径分布密度函数，分析超细颗粒表面能和气体湍流作用对流化过程中超细颗粒团聚的影响。基于Chapman-Enskog逐级渐近法，建立超细颗粒动理学模型。分析超细颗粒能量传递和耗散的变化规律，研究超细颗粒粘附聚团对颗粒相宏观流动特性的影响。采用SiO2、TiO2和Al2O3 超细颗粒为流化颗粒，应用高速摄像技术和电容层析成像技术，进行气体-超细颗粒流化特性的实验研究，研究气体-超细颗粒流态变化规律。结合考虑超细颗粒脉动流动效应的气相大涡模拟和超细颗粒动理学，建立流化床气体-超细颗粒气固两相欧拉-欧拉双流体模型，研究气体-超细颗粒两相流动流体动力特性。为正确预测气体-超细颗粒两相流动、传热传质和反应过程和工程应用奠定理论基础。

中文关键词： 超细颗粒动理学；流化床；颗粒团聚；实验测量；数值模拟

英文摘要： Both comprehensive physical model describing the agglomeration behavior in fluidization of ultrafine powders and experiments are studied on the basis of kinetic theory of gases in a circulating fluidized bed. The key issue is that both hydrodynamic and interparticle forces between particles due to the collision of agglomeration are of importance. The collision dynamics of ultrafine powders is investigated to consider the energy dissipation caused by agglomeration of ultrafine powders. The momentum and energy transfer and exchange during collisions are analyzed. The quadrature method of moments (QMOM) is proposed to treat the variation of number density of particles using weighted quadrature points (abscissas) in phase space. The influence of surface cohesion of particle-particle bindings and gas turbulence on the change of number density due to agglomeration is analyzed. By defining a new distribution function of the instantaneous particle velocity relative to the average velocity based on the volume fraction of the particulate phase that was conserved upon agglomeration, the kinetic theory of ultrafine powders flow is proposed by the Chapman-Enskog expansion approach used in the kinetic theory of gases. The constitutive equations for pressure, viscosity and energy dissipation of ultrafine powders are presented.

英文关键词： Kinetic theory of superfine powders；Fluidized bed；Agglomeration of particles；Experimental measurments；Numerical simulations