喷吹天然气条件下高炉主要工艺参数的研究

摘要：随着高炉喷吹天然气技术的应用推广，需要对天然气在高炉内的热力学行为及其操作参数的变化进行研究。利用热力学第二定律，分析了喷吹天然气在高炉内的热力学还原行为。并以物料平衡和热量平衡模型为基础，探讨了鼓风富氧、鼓风温度、鼓风湿度等工艺参量对喷吹天然气后高炉炉腹煤气量和风口回旋区理论燃烧温度的影响及其变化。利用高炉操作参数对炉腹煤气量和理论燃烧温度影响结果进行线性回归，实现定量分析各因素之间的动态耦合效果。研究结果表明：天然气首先在高温下吸热裂解成CO和H2，有助于提高煤气中CO和H2的体积分数和还原势，促进间接还原反应的进行。高炉喷吹天然气导致炉腹煤气量快速升高，理论燃烧温度快速降低。鼓风湿度的变化对炉腹煤气量和理论燃烧温度影响很大，富氧率其次。而风温变化潜力有限，对炉腹煤气量和理论燃烧温度影响相对较小。

Research on main technical parameters of blast furnace with natural gas injection

Abstract： With the application and popularization of blowing natural gas in blast furnace, it is necessary to study the thermodynamic behavior of natural gas and the variation of operating parameters in blast furnace. By the second law of thermodynamics, the reduction behavior of blowing natural gas in blast furnaces was analyzed. Based on the material balance and heat balance model, the influence of oxygen enrichment, blast temperature and humidity on the blast furnace bosh gas volume and the theoretical combustion temperature in the front of tuyere raceway after natural gas injection were discussed. The quantitative analysis of dynamic coupling effect was realized by linear regression on the effect of key parameters. The results show that natural gas first absorbs heat at high temperature and cracks into CO and H2, which helps to improve the volume fraction and reduction potential of CO and H2 in the gas and promote the indirect reduction reaction. Natural gas injection into blast furnace leads to the rapid increase in the bosh gas volume and the rapid decrease in the theoretical combustion temperature. The change of humidity has a great influence on the bosh gas volume and the theoretical combustion temperature, followed by the oxygen enrichment. However, the blast temperature has a mild influence due to the limited potential to change relatively.