摘要
随着制氢技术的发展,气基直接还原竖炉使用绿色H_(2)作为还原剂进行生产变得可行。在诸多非高炉炼铁技术中,富氢直接还原竖炉工艺有望解决传统高炉长流程工艺CO_(2)排放高的问题。但富氢直接还原竖炉面临的共性问题是还原煤气中H_(2)体积分数过高时还原吸热导致炉内热量不足,从而影响煤气利用率和金属化率。如何调整还原煤气φ(CO)∶φ(H_(2)),使CO还原过程释放热量来弥补H_(2)还原吸收的热量,并配合其他操作参数及炉型结构的优化,实现充分利用还原煤气中物理能与化学能,从而提高煤气利用率及金属化率,成为富氢直接还原竖炉亟需解决的问题。建立了富氢直接还原竖炉二维CFD数学模型,考察还原煤气中φ(CO)∶φ(H_(2))对竖炉内温度场、浓度场分布的影响规律。数学模型的正确性通过与实际工厂数据对比得以验证。模拟结果显示,当还原煤气中H_(2)体积分数上升时,竖炉内温度整体持续下降。随着还原煤气中H_(2)体积分数逐渐升高,H_(2)利用系数逐渐下降、CO利用系数缓慢增长,煤气综合利用系数呈现先上升后下降的趋势,当H_(2)体积分数为60%时,综合利用系数达到最高,为0.28。随着H_(2)体积分数的升高,竖炉出口铁摩尔分数呈现先上升后下降的趋势,当H_(2)体积分数为40%~50%时,铁摩尔分数最高可达95.67%。实际生产过程中,还原煤气中φ(CO)∶φ(H_(2))维持在40%∶60%左右可获得较高的煤气利用率及产品金属化率。
With the development of hydrogen production technology,it is feasible to use green hydrogen as a reducing agent in gas-based direct reduction shaft furnace.Among many non-blast furnace ironmaking technologies,the hydrogen-rich direct reduction shaft furnace process is expected to solve the problem of high CO_(2)emission in traditional blast furnace long process.However,the common problem faced by the hydrogen-rich direct reduction shaft furnace is that when the volume percent of H_(2)is too high,the reduction heat absorption leads to insufficient heat in the furnace,which affects the gas utilization rate and metallization rate.How to adjust theφ(CO)∶φ(H_(2))of reduction gas,make the CO reduction process release heat to make up for the heat absorbed by H_(2)reduction,and cooperate with other operating parameters and the optimization of furnace structure to fully utilize the physical energy and chemical energy,so as to improve the utilization rate of gas and metallization rate,has become an urgent problem to be solved for the hydrogen-rich direct reduction shaft furnace.In order to solve this problem,this paper established a two-dimensional CFD mathematical model of hydrogen-rich direct reduction shaft furnace,and investigated the influence ofφ(CO)∶φ(H_(2))in reduction gas on the multiphase and multi-field distribution of shaft furnace.The CFD model was validated by means of comparing simulation results with industrial test data.The results show that when the volume percent of H_(2)in the reduction gas increases,the temperature in the shaft furnace continues to decrease.With the increase of the volume percent of H_(2),the utilization coefficient of H_(2)decreases while the utilization coefficient of CO increased slowly.The comprehensive utilization coefficient of reducing gas shows a trend of first increasing and then decreasing.When the volume percent of H_(2)is 60%,the comprehensive utilization coefficient reaches the highest of 0.28.The mole percent of Fe concentration at the outlet of the furnace shows a trend of first increasing and then decreasing with the increase of the volume percent of H_(2).When the volume percent of H_(2)is 40%-50%,the highest mole percent of Fe can reach 95.67%.In the actual practice,maintaining theφ(CO)∶φ(H_(2))in the reduced gas at around 40%∶60%can achieve high gas utilization rate and product metallization rate.
作者
田旭
周恒
黄健
蔡皓宇
寇明银
吴胜利
TIAN Xu;ZHOU Heng;HUANG Jian;CAI Haoyu;KOU Mingyin;WU Shengli(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Automation and Electrical Engineering,University of Science and Technology Beijing,Beijing 100083,China;Ironmaking Technology Department,Beijing Jianlong Heavy Industry Group Co.,Ltd.,Beijing 100070,China)
出处
《钢铁》
CAS
CSCD
北大核心
2024年第1期34-40,57,共8页
Iron and Steel
基金
国家自然科学基金资助项目(51904023)
北京科技大学青年教师学科交叉研究资助项目(中央高校基本科研业务费专项资金资助项目)(FRF-IDRY-21-027)。
作者简介
田旭(1999-),男,硕士生,E-mail:Tianxu2104@163.com;通信作者:周恒(1988-),男,博士,副教授,E-mail:zhouheng@ustb.edu.cn。
