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高炉喷吹煤粉时,由于煤粉的不完全燃烧,在回旋区处会产生未燃煤粉,影响高炉的透气性。建立了气固两相湍流和煤粉燃烧的三维数学模型,并且验证了该模型的可靠性。用所建模型对由直吹管、风口、回旋区和焦炭床构成的高炉下部区域进行了喷吹煤粉流动与燃烧现象的模拟研究。模拟结果揭示了高炉炉内气固流动和煤粉燃烧的基本性质和特点;通过正交试验方法研究不同操作因素对评价指标煤粉燃尽率的影响,得到4个操作因素对燃尽率的影响程度依次分别为喷煤量、富氧率、鼓风量和鼓风温度。而工况(喷煤量1 25kg/t,鼓风量1 950m3/min,鼓风温度1 523K,富氧率5.0%)为最佳优化工况,可实现提高喷煤量和煤粉燃尽率的效果。
Blast furnace injection of pulverized coal, due to incomplete combustion of pulverized coal in the cyclone will produce unburned coal, affecting the breathability of the blast furnace. A three-dimensional mathematical model of gas-solid two-phase turbulence and pulverized coal combustion was established, and the reliability of the model was verified. The modeling of the pulverized coal flow and combustion in the lower region of blast furnace, which is composed of straight blow pipe, tuyere, convolution zone and coke bed, was carried out with the model. The simulation results revealed the basic properties and characteristics of gas-solid flow and pulverized coal combustion in blast furnace. The effects of different operating factors on burnout rate of coal index were studied by orthogonal test. The effects of four operating factors on burnout rate Affected degrees were respectively coal injection, oxygen enrichment rate, blast volume and blast temperature. The conditions (coal injection rate of 1 25kg / t, the blast volume of 1950m3 / min, the blast temperature of 1 523K, oxygen enrichment rate of 5.0%) for the best optimization conditions, can improve the amount of coal injection and burnout rate Effect.