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建立了直吹管内气固流动、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直吹管内的气体成分和温度变化,并重点考察了煤粉粒径、鼓风含氧量和鼓风温度等操作参数对煤粉燃尽率的影响。研究结果表明:减小粒径、增加含氧量、提高鼓风温度都可以使煤粉在直吹管内的燃尽率得到提高。煤粉在直吹管内的燃烧行为以挥发分的脱除为主,该过程对温度敏感,而对氧气浓度不敏感。这一结论与前人在回旋区内得到的模拟结果相反。因此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和回旋区。
The mathematical model of gas-solid flow, heat transfer and pulverized coal combustion in direct blow pipe was established. Based on the actual blast furnace process parameters, the gas compositions and temperature changes in the straight blow pipe were studied by means of commercial software through numerical simulation. The effect of operating parameters such as particle size, blowing oxygen content and blasting temperature on burnout rate of coal was studied. The results show that the burn-out rate of pulverized coal in the straight-blowing tube can be increased by reducing the particle size, increasing the oxygen content and increasing the blowing temperature. The combustion behavior of pulverized coal in straight blow pipe is dominated by the removal of volatile matter, which is temperature-sensitive and insensitive to oxygen concentration. This conclusion is contrary to the simulation results obtained by predecessors in the cyclotron region. Therefore, when studying the effect of variables on the burn-out rate of pulverized coal injection, the simulation zone should include both the straight-blowing tube and the convolution zone.