【作者】 梁新腾；

【导师】 张捷宇；

【作者基本信息】 内蒙古科技大学 ， 钢铁冶金， 2007， 硕士

【摘要】 随着炼钢技术的不断发展,对连铸钢的清洁度和铸坯质量的要求也越来越高。对中间包内钢液的流场进行研究和分析,保证钢液流动状态的合理性具有相当重要的理论和实际意义。本文采用数学物理模拟的研究方法以宝钢4#板坯连铸中间包为研究对象进行流动与传热耦合过程的三维数值模拟研究。运用大型通用有限元分析软件ANSYS CFX,建立了各类中间包有限元模型,计算不同条件下中间包的流场,并结合瞬态状况下算出的RTD曲线,分析了堰坝组合的数量、次序和位置对中间包内流场的影响,并优化了中间包的结构。同时文中还探讨了中间包水力学模拟的问题,本文利用相似原理建立了1:3的缩小比例模型,采用“刺激——响应”实验技术,使用饱和盐溶液作为示踪剂,测定了各出水口处电导率值随时间变化的数据,得出RTD曲线,计算出钢水在中间包内的平均停留时间,中间包内的死区、活塞区及混合区的体积比率。还用了对流场染色的方法,进行观察、拍照,分析流场状态。研究表明:(1)与有坝堰等控流装置的中间包相比,不采用任何流动控制装置(空包)时中间包内存在较大死区,不利于夹杂物上浮。(2)外方提供的方案由于其远端低坝安装位置不是很合理,所以并非最佳选择,调整远端低坝安装位置至阶梯平台之上的优化方案可以达到更好效果。(3)在所采用的中间包内控流装置中,近水口端方案采用方案1(堰距水口中心距离600,坝堰中心间距离400,堰底距包底距离300,坝高度400,坝厚度)的挡墙、坝以及其安装位置的实验效果最佳;远水口端方案采用方案10(堰距水口中心距离1500,坝堰中心间距离600,堰底距包底距离250,坝高度430)方案更佳。(4)针对宝钢实际情况,优化实验方案test3内型合理,推荐采用优化实验方案test3。参数如下:湍流控制器采用宝钢现有湍流控制器,坝堰间距:450mm,堰距中间包底部距离:300mm,堰距长水口距离:1750mm,坝高:500mm。更多还原

【Abstract】 With the development of steel-making technology, it becomes more and more important to improve the cleanlines and quality of casting steel. Therefore, it is very significant both in theory and practical application to study and analyze the flow field and temperature field of molten steel in tundish.The thesis makes research on the tundish of No.4 slab caster of Bao-steel. Three-dimensional mathematical models are currently being used successfully to simulate liquid steel flow and temperature distribution, the large-scale universal Finite Element analyses software ANSYS CFX is used and many models based on different tundishes are built. By calculating the flow fields in the tundishes with different conditions, analyzing the average residence time in the tundish under transient condition, then the assembled number, the installing order and location of weir and dam are confirmed to have influence on the flow field in tundish, then the structure of tundish is optimized. In the meantime, the water simulation is studied in the paper .And build the scale of 1:3 model based on similarity theory and‘stimulate-response’technology is applied. The trace is the saturated salt solution. We measure the conductance against the tracer concentration. The RTD curves are drawn. Then we calculate the average residence time and study the proportions of dead、plug、mixed volume. According to their effects, the conclusions are as follows:(1) Compared with the tundish setting with weir、dam, the tundish has bigger area of dead zone without flow control devices, not be beneficial to inclusions removal.(2) The design of dam is not very appropriate in the case provided by Danieli. So it’s not the best choice. a good result can be achieved by adjusting the dam to the top of ladder in the tundish.(3) Under the cases with flow control devices, among the cases near the inlet, the scheme 1 (the distance between weir and inlet is 600mm, the distance between dam and weir is 400mm, the high between the bottom and weir is 300mm, the high of dam is 400mm)is better. Among the cases far from the inlet, the scheme 10(the distance between weir and inlet is 1500mm, the distance between dam and weir is 600mm, the high between the bottom and weir is 250mm, the high of dam is 430mm)is better. (4) For the practice of Bao-steel, Optimized case is test3. Paramater as following: The turbulence inhabiting pouring pad Bao-steel now used is selected, the distance between dam and weir is 450mm, the high between the bottom and weir is 300mm, the distance between weir and inlet is 1750mm, the high of dam is 500mm.更多还原