回旋区内喷吹煤粉燃烧行为的数值模拟

建立了直吹管-风口-回旋区下部区域内气固流动、传热和煤粉燃烧的数学模型，基于实际高炉工艺参数，借助商业软件通过数值模拟的方法研究了煤粉粒度、鼓风含氧量和鼓风温度对煤粉燃尽率的影响. 结果表明，煤粉粒径由120 mm降低到70 mm，燃尽率提高35.928%；鼓风含氧量由21%增加到30%，燃尽率上升16.542%；而鼓风温度由1423 K增加到1498 K，燃尽率仅提高8.897%. 脱挥发分过程和氧气供应是决定燃尽率高低的两大因素. 此外，在研究变量对喷吹煤粉燃尽率的影响时，模拟区域应同时包含直吹管、风口和回旋区.

Numerical Simulation of Pulverized Coal Combustion in Raceway

A mathematical model of gas-solid flow, heat transfer and pulverized coal combustion in the region of blowpipe-tuyere-raceway bottom was developed. Based on the technological parameters of practical blast furnace, the effects of coal particle size, oxygen enrichment and blast gas temperature on the burnout rate of pulverized coal were studied by numerical simulation. The results indicate that when the coal particle diameter changes from 120 to 70 μm, the burnout rate is increased by 35.928%, when the oxygen content in the blast gas is reduced from 30% to 21%, the burnout rate is decreased by 16.542%, and when the blast gas temperature is increased from 1423 to 1498 K, the burnout rate is raised by only 8.897%. Devolatilization process and oxygen availability are dominant factors for coal burnout. In addition, in examination of the influences of variables on pulverized coal burnout, the simulation region should include blowpipe, tuyere and raceway.