基于机理模型的不锈钢侧顶复吹AOD精炼过程控制

Process control of combined side and top blowing AOD refining of stainless steel on the basis of a mechanism model

基于对不锈钢侧顶复吹AOD精炼提出的数学模型研制了相应的过程控制模型.该模型包括气体、物料添加及精炼和温度3个模块,按一维瞬态导热处理炉壁传热.应用于120 t AOD炉内14炉304型不锈钢精炼,结果表明:该模型可较精确地控制精炼过程中各物料添加量和吹氧量,给出的各还原终点的钢液成分和温度与实测值较相符;得到的钢液成分和温度随精炼时间的变化规律与依二维瞬态导热分析炉壁热损的过程数学模型估计完全一致,但数值上有一定的偏差.该模型可为基于机理模型进一步研制新的过程控制系统提供可靠的基础.

Based on Wei et al. ~ mathematical model for the combined side and top blowing AOD refining process of stainless steel, a relevant control model of the process was developed. The model includes three modules of gas blowing, material addition, and refining with temperature. The heat transfer of the vessel is treated in terms of the one-dimensional transient heat conduction. Applying it to 14 heats of 304-grade stainless steelmaking in a 120 t AOD converter, the results show that the model can more precisely control the addi- tion amounts of the materials and the oxygen blowing rate in the refining process ; the composition and temperatures of molten steel at the reductive endpoints given by it are in better agreement with the determined values. The obtained changing patterns of the composi- tion and temperature of liquid steel with the refining time are entirely consistent with those predicted by the mathematical model of the process with analyzing of the vessel heat losses according to the two-dimensional transient conduction, but there are numerically certain deviations between them. The model can provide a reliable basis for further developing a new control system on the basis of a mechanism model of the process.