大型高炉回旋区内气-固流动行为研究

Study on gas-solid flow behavior in large blast furnace raceway

以国内某3200 m^(3)高炉鼓风参数为依据,采用计算流体力学-离散单元法(CFD-DEM)耦合的方法,模拟研究了高炉回旋区动态演化过程,分析了焦炭颗粒接触特性及流化状态。结果表明,初始鼓风阶段回旋区高度的增量大于深度的增量,持续鼓风,回旋区尺寸逐渐稳定,焦炭颗粒的低配位数增多,高配位数减少,回旋区边缘焦炭颗粒趋于流态化;同一速度下,随着风口面积增大,回旋区内气体与焦炭颗粒之间的曳力增大,焦炭颗粒接触力减弱,接触概率降低,加剧回旋区内焦炭颗粒流态化程度。

In the paper,based on the blast parameters of a 3200 m^(3)blast furnace,the dynamic evolution process of the blast furnace raceway is simulated and investigated by the coupled Computational Fluid Dynamics-Discrete Element Method(CFD-DEM).The contact characteristics and fluidization state of coke particles were analyzed.The results indicate that the rate of change in the height of the raceway is greater than the depth during the initial blast phase.With the continuous blasting,the size of the raceway gradually tends to be stabilized,the low coordination numbers of coke particles system in the raceway are increasing,and the high coordination numbers are decreasing,the coke particles tend to be fluidized.Increasing of the tuyere area at the same speed enhances the drag force between the gas and coke particles in the raceway,weakens the contact force of the coke particles,reduces the contact probability,and consequently promotes fluidization of coke particles in the raceway.