摘要
合理控制中间包的流场有利于促进钢液中夹杂物上浮、均匀钢液成分和温度。水模型试验和数值模拟是两种主要的中间包流场研究方法,各有优缺点应相互补充。数值模拟成本低廉速度快,但受限于边界条件的不确定性和湍流模型的局限性难以完全真实反映中间包内的流场。水模型试验能够较为准确地模拟中间包内流场,但无法准确模拟温度场、水口结瘤、覆盖剂和吹气等对中间包流场的影响。研究表明,湍流控制器对降低长水口钢液射流的湍动能、均匀钢液温度和成分、聚拢射流让其转向向上流动降低死区体积分数、延长平均停留时间和优化流场结构具有很好的作用。湍流控制器、堰、坝和导流挡墙合理组合,协同发挥的控流效果,优于单一控流装置的效果。合理调节堰与包底距离、挡坝高度、堰与挡坝距离、堰与出流口距离、挡坝开孔的个数、尺寸和角度,可以优化中间包流场,促进夹杂物去除。气幕挡墙对钢液进行气洗可以提高钢液洁净度。环形气幕挡墙解决了条形气幕挡墙夹杂物去除率低、且不稳定的问题,提高了夹杂物去除率。最后,中间包流场数学模型精细化,并考虑连铸过程中更多工艺与边界条件的影响是未来发展的趋势。对于中间包流场研究的特定问题,针对性设定优化指标,会使得优化研究工作事半功倍。水模型试验作为中间包控流技术的另一种重要研究手段,同样越趋精确化,不断有研究者以提高试验精度为目的在试验方法和测量原理上进行探索和创新。
By reasonably controlling the flow field in the tundish,the inclusions in the molten steel can be promoted to rise and the composition and temperature of molten steel can be homogenized.Water model experiment and numerical simulation are two main methods to study the flow field in tundish,each of which has its own advantages and disadvantages and should complement each other.Numerical simulation is cheap and fast,but due to the uncertainty of boundary conditions and the limitation of turbulence model,it is difficult to fully reflect the flow field in the tundish.The model test can accurately simulate the flow field in the tundish,but it cannot accurately simulate the influence of temperature field,nodule,covering agent and blowing on the flow field in the tundish.The results show that the turbulence controller has a good effect on reducing the turbulent kinetic energy of the molten steel jet from long nozzle,homogenizing the temperature and compositions of the molten steel,diverting the liquid steel jet upward to reduce the volume fraction of dead zone,prolonging the average residence time and optimizing the flow field structure.The combination of turbulence controllers with weir,dam and diversion wall is better than that using single flow control device.The tundish flow field can be optimized and the inclusion removal can be promoted by reasonably adjusting the distance between the weir and the tundish bottom,the height of the dam,the distance between the weir and the dam,the distance between the weir and the outlet,the number,size and angle of the opening of the dam.The gas curtain wall improves the cleanliness of liquid steel.The annular gas curtain can solve the problem of low and unstable inclusion removal ratio with the strip gas curtain to improve the inclusion removal ratio.Finally,it is the trend that the mathematical model of tundish flow field is refined and the influence of more process and boundary conditions is considered.For the specific research of tundish flow field,the optimization index can be
作者
刘逸波
杨健
LIU Yi-bo;YANG Jian(State Key Laboratory of Advanced Special Steel,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)
出处
《连铸》
2021年第5期12-33,共22页
Continuous Casting
基金
国家自然科学基金资助项目(U1960202)。
关键词
中间包
模拟方法
控流装置
吹氩
夹杂物
tundish
simulation method
flow control device
argon blowing
inclusion
