NUMERICAL SIMULATION OF AIR AND COKE PARTICLEMOTIONS IN BLAST FURNACE TO MINUMIZE CO_2 EMISSION

采用离散元法计算焦炭颗粒间的多体相互作用，基于蒙特-卡罗直接模拟的硬球模型计算粉末颗粒间的两体相互作用，有限差分法对含气固相互作用项的Navier-Stokes方程进行数值分析，对真实的高炉内的颗粒和气体流动进行了数值模拟。在模拟中，我们考虑了软化、熔化、内聚区和内聚物的存在。计算结果显示了不同的流动模式，这些波动和它的不同周期。计算结果还显示了焦炭、粉末和气体的速度分布以及这些颗粒的填充比分布。其动力学特性是波动和不稳定的。由于空气的作用，在下芯和下壁区域中形成高度填充的焦炭和粉末颗粒层 关于我们 and these particle粒子flows流.高风速区出现在软化熔聚区与高度填充的炉下芯区之间的层内，而不稳定的高风速区则由软化熔聚区的存在和消失在炉壁附近和回旋区上产生。焦炭和粉末颗粒以及软化的熔融粘结区将导致炉内的不稳定状态。粉末颗粒在颗粒碰撞和颗粒团破碎的作用下，呈圆形扩散，形成圆形多层粉末颗粒团。一些粉末颗粒向上流动，而另一些则被颗粒和空气流填充在炉的下芯区域中。计算结果给出了一个高炉内异常现象的实例，即炉心区域由于软化熔融粘结区、粘结物和焦炭颗粒尺寸减小的作用，形成了异常高的与炉壁接触的大风速区。少

We have numerically simulated the particle and gas flows in a real blast furnace using Distinct Element Method for the computation of the multi body interaction among coke particles, Hard Sphere Model for two body interaction of powder particles based on Direct Simulation of Monte-Carlo Method and Finite Difference Method for the numerical analysis of Navier-Stokes equations with the interaction terms between gas and particles for the gas flows. In the simulations we have taken the existence of softening melting cohesive zones and cohesive matters into account. The calculation results indicate the various flow patterns, those fluctuations and its various periods. The results also indicate the velocity distributions of coke, powder and gas, and packing ratio distributions of these particles. The dynamical characteristics fluctuate and are unstable. The highly packed coke and powder particle layers are formed in the lower core and in the lower wall regions under the tuyere due to the air … More and these particle flows. The high air velocity region appears in the layer between the softening melting cohesive zones and the highly packed furnace lower core region, and the unstable high air velocity region is produced near the furnace wall and on the raceway by the existence and the disappearance of softening melting cohesive zones. The coke and powder particles and the softening melting cohesive zones would yield the unstable state in the furnace. The powder particles circularly spread and make the circularly multi-layered powder particle clusters caused by the particle collisions and the breakage of clusters. Some of the powder particles flow upward and others are packed in the furnace lower core region by the particle and the air flows. Our calculated results present an unusual phenomenon example in the blast furnace, that is, the unusual high air velocity wide region touched to the furnace wall is formed due to the effect of the softening melting cohesive zone, the cohesive matter and the size reduction of coke particles in the furnace center region. Less