非直接测量变量对转炉热平衡计算的影响和评估

Influence and evaluation of indirect measurement variables on calculation of BOF thermal equilibrium

为进一步提高转炉热平衡计算的精度、提升终点温度控制水平,基于210 t转炉自动炼钢工业实践,通过工业试验测定、数据回归方法研究了非直接测量变量(铁水温度变化、铁水碳含量、转炉生产过程中的铁水装入、补炉、空炉以及炉衬热状态等因素)对热平衡计算的影响,并提出了具体的算法和经验公式。结果表明,使用铁水中碳的饱和溶解度对直接化验碳含量进行修正,可以更真实地反映铁水碳含量水平,减小热平衡计算过程中总耗氧量的误差。生产中可根据前炉次的平均出钢温度来评估炉衬蓄热能力,从而实现对下炉次热平衡计算的修正,减小热力学理论计算偏差。经过持续优化后,转炉炼钢过程热平衡计算误差显著降低,终点温度命中率由70%提升至90%以上,实现了转炉自动炼钢出钢温度的精准控制。

In order to further improve the accuracy of thermal equilibrium calculation and improve the temperature control level of end point for BOF,based on the industrial practice of 210 t BOF automatic steelmaking,the influence of indirect measurement variables(hot metal temperature change,carbon content of hot metal,hot metal loading in BOF production process,furnace fettling,empty furnace,and thermal state of furnace lining)on thermal equilibrium calculation was studied by industrial test and data regression method,and specific algorithms and empirical equations were developed.The results show that using the saturated solubility of carbon in hot metal to correct the direct test carbon content can more truly reflect the level of carbon content in hot metal and reduce the error of total oxygen consumption in the process of thermal equilibrium calculation.In production,the heat storage capacity of the furnace lining can be measured according to the average tapping temperature level of the previous heat,so as to realize the correction for the thermal equilibrium calculation of the next heat and reduce the calculation deviation of thermodynamic theory.After continuous optimization,the error of thermal equilibrium calculation in BOF steelmaking process is significantly reduced,and the hit rate of endpoint temperature is increased from 70%to more than 90%,which realizes the accurate control of tapping temperature in BOF automatic steelmaking.