【作者】 张琳；

【导师】 高宪文； 蒋学军；

【作者基本信息】 东北大学 ， 控制工程， 2008， 硕士

【摘要】 连铸机的二次冷却对铸坯质量至关重要。其他工艺条件不变时,二冷强度增加及拉坯速度的提高,都可以提高铸机的生产率；但同时,二冷参数配置不当是导致铸坯产生各种质量缺陷的主要原因之一。二次冷却方法有静态控制和动态控制,其中动态控制能很好的适应变拉速的情况,将铸坯温度控制在合理范围内。随着计算机性能和自动化水平的日益提高,动态二冷配水已经广泛应用于连铸生产线,对于提高铸坯质量起到了巨大作用。本课题以首钢二炼钢板坯连铸机为研发基础,通过对板坯连铸凝固传热数学模型的理论研究,先对其静态配水进行分析,并在此基础上设计了二冷水表和二冷动态配水软件,对其生产工艺参数进行优化。在传热数学模型上,采用数值法对方程进行求解。模型根据数据库中存储的钢种的热物性参数、拉速、冷却水量、中间包温度计算铸坯温度与凝固状态。动态配水模型以坯龄法为基础,坯龄法是将连铸坯分为众多单元切片,分别对各个切片进行跟踪,根据切片的生成时间进行配水的方法。根据模拟和现场实验证明,坯龄模型能较好地在变拉速条件下控制铸坯表面温度的波动。此外动态配水中还采用目标温度控制法对水量进行校正,进一步减小了铸坯表面温度波动。在传热数学模型与坯龄模型的基础上,开发了动态配水软件。此软件包含离线模式与在线模式,利用离线模式设计了水表,并用于现场生产。在线模式将动态配水应用于生产。该软件不仅提供良好的用户界面和方便的数据库管理,还能详细记录生产过程中各类参数,有利于对铸机的生产运行状态进行分析和工艺优化。结果表明离线模型所设计的水表能满足铸坯质量的要求,动态配水能较好适应变拉速的情况,使温度控制在合理范围内。这对于提高铸坯质量和新钢种的配水设计与评价都有其现实意义。更多还原

【Abstract】 The control of secondary cooling holds very important status during continuous casting. When other technical condition remain unchanged, the intensity of cold and increase the speed of casting are all can improve the productivity of casting machine. However, at the same time the cold parameters are not improper is one of the main reason of various defects. Secondary cooling control includes steady cooling control and dynamic cooling control, dynamic cooling control can adaptive the change of the situation very well. the slab temperature control within reasonable limits. With the increasing of computer performance, and automation level, dynamic secondary cooling water distribution has been widely used in continuous casting production lines, It plays a tremendous role in raising the slab quality.This subject take the Shougang steel slab continuous casting machine as research and development base, through studying the theory of the slab continuous casting and solidification heat transfer mathematical model, the analysis of its static allocation of water is done firstly. The two cold-water table and the dynamic cold water distribution software, which can optimize the process parameters, is designed based on this.In the heat transfer model, numerical methods is used to solve the equation. According to the database model stored in steel thermal physical parameters, casting speed, cooling water, tundish temperature and the temperature calculated solidification state.The dynamic cooling system is based on the residence time method in which the slab is divided into many slices which are tracked. The water flow rate is determined mainly by the residence time of the slices. The residence time method can soundly control the fluctuation of slab surface temperature, which is verified by both simulation and plant trial. In addition, the method of aim temperature control is applied to reduce the fluctuation of slab surface temperature further.Water distribution software is developed based on the heat transfer model and the old model of billet. This software includes online and offline mode model, using a meter off-line mode design and produce for the scene. Dynamic online distribution model will be applied to production. The software not only provide a good user interface and ease of database management, but also save a detailed of the various parameters of the production process, this is conducive to the production of casting machine running for analyzing and process optimization.The results adapting that the water meter designed by the offline model can meet the slab quality requirements. The hydro-dynamic can better adapt the variable speed,it also make the temperature in a reasonable limits. This method has practical significance to improve quality and new steel slab of the water distribution design and evaluation.更多还原