In order to investigate the fluidization characteristics in fluidized bed with wide particle size distribution, the Computation Fluid Mechanics (CFD) was used to simulate the gas-solid flow hydrodynamic characteristics in turbulent fluidized bed under different operation conditions. The Eulerian-Eulerian multiphase model and the SIMPLE algorithm were adopted to analyze the process of bubbles formation, growth and vanishing, and based on the kinetic theory of granular flow, the gas-solid flow characteristics in fluidized bed were studied. The results show that the numerical simulations agree well with the experimental data, and the maximum relative error of the simulation is only 10％ and the minimum relative error is lower than 1％. It indicates that the model can predict the fluidization characteristics of the system with different solid particle size distributions. It was found that the distribution of particle sizes and the energy dissipation and transmission between particles could have influence on the fluid dynamic characteristics in the fluidized bed. It was also found that the joining of fine particles can significantly change the flow characteristics of the fluidized solid particles.%为了探索气固流化床内宽筛分硅粉颗粒的流化特性,作者利用计算流体力学CFD软件,采用Eulerian气固多相流模型及SIMPLE算法,模拟了二维气固流化床内不同粒级硅粉颗粒在不同操作件下的气固流化特性;分析了气泡生成、长大和破裂的过程,研究了床内气固两相的流动特性.结果表明:模拟计算值与实验值吻合较好,最大相对误差为10%,最小误差不到1%;模型能够较好地预测不同粒径固体颗粒体系的流化特性;流化床内的流体动力学特性受颗粒尺寸分布以及颗粒间能量耗散和传递的影响,细颗粒的加入可明显改变硅粉颗粒的流化特性.
展开▼
