现代高炉高风温关键技术问题的认识与研究

提高风温可以有效降低高炉燃料消耗,促进高炉生产稳定顺行,是绿色低碳炼铁技术的重要发展方向之一。研究了热风炉热量传输过程和传热特性,通过传热学机理的研究解析,阐述热风炉加热面积与风温之间的关系,提出提高热流通量以改善热风炉传热的观点。研究了热风炉理论燃烧温度、拱顶温度和风温之间的关系,介绍了利用低热值高炉煤气和回收热风炉烟气余热,通过耦合预热和能量梯级利用的技术方法,实现高风温的技术创新及实践。提出了实现热风炉智能化操作的技术要素,论述了合理控制拱顶温度和抑制NO_x大量生成的工艺方法,以及有效预防热风炉炉壳晶间应力腐蚀的技术措施。指出实现低热值煤气的高效利用和高值转化,提高风温、降低燃料比和CO₂排放,是未来高炉炼铁的关键共性技术。

Research and cognition on key technical problems of high blast temperature for modern blast furnace

Increasing the blast temperature can effectively reduce the fuel consumption of blast furnace (BF) and promote the BF stable and smooth production, which is one of the important developing directions of green-low carbon ironmaking technology. Heat transformation process and heat transfer characteristics of hot blast stove are researched. Relationship between heating surface and blast temperature of hot blast stove is expounded through the study and analysis of heat transfer mechanism, and the viewpoint of increasing heat flux to improve heat transfer in hot blast stove is put forward. Relationships between theoretical combustion temperature, dome temperature and blast temperature of hot blast stove are studied. Technical innovation and practice of high blast temperature are introduced, which applies low calorific value blast furnace gas and recovering flue gas waste heat of hot blast stove by coupling preheating and energy cascade utilization. Technical elements to realize intelligent operation of hot blast stove are put forward. Technological methods of controlling dome temperature and suppressing large amount of NO_x,and technical measures to effectively prevent intergranular stress corrosion of hot blast stove shell are discussed. Realizing high efficiency utilization and high value conversion of low calorific value gas, increasing blast temperature, reducing fuel ratio and CO₂ emission are the key-common technologies of blast furnace ironmaking in the future.