基于差分进化算法的连铸冷却过程多目标优化

发布时间：2018-06-06 13:29

本文选题：连铸 + 二冷　；参考：《沈阳理工大学》2017年硕士论文

【摘要】：连铸二次冷却制度是影响铸坯质量的关键因素,不合理的冷却制度会使铸坯产生内部裂纹、外部裂纹、鼓肚和中心偏析等缺陷。因此,对二冷区水量进行优化,获得合理的连铸二冷配水参数具有较大的实践意义。本文以某钢厂方坯连铸机为对象,主要工作如下:一、建立铸坯凝固传热模型。铸坯凝固传热模型是模拟铸坯凝固进程和参数优化的有效工具。本文从铸坯凝固传热特点出发,对建立模型所需的物性参数做了分析、选择和计算,建立了二维传热模型,并用控制容积法对其进行求解。二、数值模拟分析工艺参数对凝固过程的影响。在传热模型的基础上,仿真分析了拉速和过热度对方坯凝固的影响(温度场、坯壳厚度),并结合冶金准则构造多目标优化目标函数,为下文二冷配水参数优化提供理论基础和数据支撑。三、开发了基于差分进化算法的连铸二冷水优化多目标优化算法。将差分进化算法应用于连铸二冷水优化的多目标优化问题的求解,讨论了多目标优化问题中要解决的关键问题,即种群多样性的保持和目标权重的处理。采用拥挤距离的方法维持种群的多样性和分布性,用层次分析法进行各优化目标函数之间的权重处理。优化结果表明,该算法能够兼顾解集的收敛性和分布性,且多次优化一致性较好。四、连铸二次冷却制度的确立。将开发的优化算法应用于连铸二冷水优化问题的求解,对水量进行优化,并拟合出基于拉速-水量的关系曲线,确定连铸二冷配水参数,构建合理的连铸二次冷却制度。将研究成果应用于生产实际,有效提高连铸质量、改进和升级连铸生产工艺。
[Abstract]:The secondary cooling system of continuous casting is the key factor to affect the quality of the billet. Unreasonable cooling system will cause the defects of the billet such as internal crack, external crack, blooming and central segregation. Therefore, it is of great practical significance to optimize the quantity of water in secondary cooling zone and obtain reasonable parameters of secondary cooling water distribution for continuous casting. The main work of this paper is as follows: firstly, the solidification heat transfer model of billet is established. The solidification heat transfer model is an effective tool to simulate the solidification process and parameter optimization. Based on the characteristics of solidification heat transfer of billet, the physical parameters needed to establish the model are analyzed, selected and calculated in this paper. The two-dimensional heat transfer model is established and solved by the control volume method. Secondly, the influence of process parameters on solidification process is analyzed by numerical simulation. Based on the heat transfer model, the effects of drawing speed and superheat on billet solidification (temperature field, shell thickness) are simulated and analyzed. It provides theoretical basis and data support for the optimization of secondary cooling water distribution parameters below. Thirdly, a multi-objective optimization algorithm for continuous casting secondary cooling water optimization based on differential evolution algorithm is developed. The differential evolution algorithm is applied to solve the multi-objective optimization problem of continuous casting secondary cooling water optimization. The key problems to be solved in the multi-objective optimization problem are discussed, that is, the preservation of population diversity and the processing of target weight. The method of congestion distance is used to maintain the diversity and distribution of the population, and the analytic hierarchy process (AHP) is used to deal with the weights among the optimization objective functions. The optimization results show that the algorithm can give consideration to the convergence and distribution of the solution set, and the consistency of multiple optimization is good. Fourth, the establishment of secondary cooling system for continuous casting. The developed optimization algorithm is applied to solve the optimization problem of secondary cooling water in continuous casting, and the water quantity is optimized. Based on the relationship curve between drawing speed and water quantity, the parameters of secondary cooling water distribution for continuous casting are determined, and a reasonable secondary cooling system for continuous casting is constructed. The research results are applied to the production practice to improve the quality of continuous casting and to improve and upgrade the production process of continuous casting.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TF777;TP18

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