熔融还原炼铁熔融气化炉移动床区域内炉料流动的离散单元法模拟

DEM Simulation of Solid Flow in the Moving Bed of COREX Melter Gasifier

建立熔融还原炼铁(coal reduction extreme,COREX)工艺熔融气化炉移动床区域炉料流动离散单元法(discrete element method,DEM)模型。通过炉料自然堆积过程的DEM模拟,确定了固体颗粒之间的滚动摩擦系数。炉料流动的DEM模拟结果与试验研究结果吻合的较好。研究了移动床区域炉料的流动规律、死料柱形状及尺寸以及颗粒间法向应力的分布规律,同时分析了风口回旋区炉料消耗速率对应力分布的影响。研究结果表明:熔融气化炉移动床区域可分为四个不同的子区域,死料柱区域法向力最大,其次为壁面附近区域,稳定流动区和活跃区内颗粒之间法向力最小。

A DEM model was set up for solid flow in the moving bed zone of COREX melter gasifier. The rolling friction coefficient of solid particles was determined by DEM simulation of natural packing for furnace burden. The DEM simulation result of solid flow coincided with that of experiment study. Flow pattern of solid,geometry and size of deadman and normal compressive force distribution were obtained. Furthermore,the effects of the discharge rate of solid particles in the raceway on the normal compressive force distribution were studied. The results show that the moving bed can be divided into four subdomains. The stagnation zone with maximum normal compressive force,the second is near-wall zone,and in steady-flow zone and active zone have minimum normal compressive force.