非稳态连铸过程拉速-冷却水协同优化方法

针对非稳态连铸冷却强度异常易导致铸坯质量缺陷的问题,从系统冷却角度提出一种改进的遗传算法对连铸拉速、冷却水等工艺进行协同优化。基于国内某钢厂3个月的工业连铸数据分析发现,开浇、终浇、换中间包、换水口等非稳态连铸由于拉速与冷却水协同不好导致冷却强度不足,影响铸坯质量与连铸效率。建立过程冷却强度优化模型,从优化目标、选择算子等方面对遗传算法进行改进,在生成可行解的同时提高模型收敛速度与优化能力。结果表明,模型优化方案符合现场工艺规则,通过适当提高二冷水量,非稳态连铸系统热量释放平均由45.87%提升至49.05%,处于合理区间内。该优化方法可为连铸系统生产管控提供指导。

Co-optimization method of casting speed-cooling water in an unsteady continuous casting process

Aiming at the problem that abnormal cooling intensity in unsteady continuous casting is easy to lead to defects in slab quality, an improved genetic algorithm was proposed to optimize the casting speed and cooling water from the perspective of system cooling. Based on the analysis of the industrial continuous casting data of a Chinese steel plant for three months, it was found that the unsteady continuous casting, such as the beginning casting, ending casting, change the nozzle, and change the tundish, due to the poor coordination between the casting speed and cooling water, leads to insufficient cooling intensity, which affects the quality of slab and continuous casting efficiency. The genetic algorithm was improved from the aspects of optimization objective and selection operator, so as to improve the convergence speed and optimization ability of the model while generating feasible solutions. The results show that the model optimization scheme met the industrial process rules, and the average heat release of the unsteady continuous casting system was increased from 45.87% to 49.05%, which is within a reasonable range, by appropriately increasing the secondary cooling water flow rate. This optimization method could guide the production control for the continuous casting system.