宽板坯连铸结晶器浸入式水口结构优化的研究

针对宽板坯连铸生产现状,采用商业软件PHOENICS对其建立三维数值模型,模拟宽板坯连铸结晶内钢液的流场分布.研究了不同水口倾角、插入深度及拉速等参数条件对结晶器内流场的影响,得出了适用于宽规格结晶器合理的浸入式水口.这为优化宽板坯结晶器内钢液的流场及浸入式水口结构及确定合理的工艺参数提供了科学依据.     

宽板坯结晶器浸入式水口结构优化的数值模拟

以某钢厂宽板坯连铸结晶器为研究对象,利用商业软件PHOENICS建立一个三维有限差分模型,模拟宽板坯连铸结晶器内钢液的流动分布.通过分析水口底型、倾角、插入深度等工艺参数对钢液面波动、流股对结晶器窄面的冲击力及涡心高度的影响,得出适用于宽规格结晶器的合理的浸入式水口.通过研究,为优化宽板坯结晶器内钢液的流场及浸入式水口的设计提供了科学依据.     

攀钢板坯连铸结晶器内流场的水力学模拟研究

采用水力学模拟方法研究攀钢板坯连铸结晶器内流场,分析浸入式水口结构尺寸、塞棒吹Ａｒ量和拉速等工艺参数对连铸结晶器内钢液流动状况的影响,在此基础上优选出适合攀钢板坯连铸工艺的浸入工水口结构尺寸及相关参数。     

SEN壁厚对结晶器内钢液流场和温度场的影响

针对板坯连铸结晶器,利用PHOENICS软件,计算结晶器内流体的三维流场和温度场,比较和分析了浸入式水口壁厚对结晶器内流场和温度场的影响,为优化浸入式水口结构参数提供参考。     

板坯连铸结晶器内钢液流动数值模拟

利用商业软件ＰＨＯＥＮＩＣＳ，建立一个三维有限差分模型，对板坯连铸结晶器内钢流流动进行数值模拟，重点研究了浸入式水口结构尺寸和工艺参数对连铸结晶器内液面紊动能和窄面冲击压力分布影响，同时还将计算结果与水模实验结果进行了比较，二者吻合较好。     

板坯连铸结晶器内液面波动的水模型研究

以某厂板坯连铸结晶器为原型,采用1:1的水模型进行试验,以瞬时波高为判断依据,研究了拉速、浸入式水口出口角度、水口浸入深度、水口底面结构等工艺参数对板坯结晶器内流场和液面波动行为的影响.提出了优化结晶器流场的工艺参数,为在实际生产中减少结晶器内卷渣提供了依据.结果表明:拉速对板坯连铸结晶器内液面波动的影响最大,水口倾角...     

板坯连铸结晶器内钢液流动过程的模拟仿真

板坯连铸结晶器内钢液的流动方式对去除钢水中夹杂物，防止残渣和保护渣卷入钢水，防止注流冲刷凝固固造成漏网和拉裂很重要。本文开发了描述结晶器内三维湍流流动的数学模型和计算程序Ｍｏｕｌｄ１．０，对结晶器内的流动现象进行了模拟研究，观察了双侧孔浸入式水口的张角和浸入深度及浇铸速度对结晶器内流动行为的影响。计算模拟结果与实测结果进行了比较。     

八钢板坯连铸中包浸入式水口结构的优化

总结了板坯连铸结晶器浸入式水口对结晶器流场的影响,通过数学模拟及现场大量试验。选定了适合八钢板坯连铸现场条件的浸入式水口,解决了结晶器角部扰动的问题,提高了板坯质量。     

高拉速厚板坯连铸结晶器流场影响因素的模拟研究

运用数值模拟研究方法,研究高拉速厚板坯连铸结晶器流场的影响因素;研究浸入式水口结构、水口控流方式、水口出口角度、水口浸入深度、结晶器宽度、结晶器厚度、吹氩等因素对结晶器流场、液面流速以及初生坯壳的影响.结果表明在高拉速下,结晶器的流场不稳定因素增多,工艺参数对结晶器流场的影响因数增加.在高拉速下结晶器流场流速高,液面波动大,液钢流束冲击深度大,势必造成产品质量的下降趋势,因此高拉速厚板坯连铸过程必须采用电磁制动或流场控制技术,降低高流速带来的不利影响;水口结构与结晶器规格最优化与匹配能得到适宜的结晶器流场;同时发现高拉速钢液流束对结晶器初生坯壳的影响严重,是高拉速漏钢率高的直接原因之一.     

板坯连铸结晶器内吹入气体对钢液行为的影响

采用水力学模拟方法研究板坯连铸结晶器内流场，分析塞棒吹Ａｒ时，浸入式水口琢拉速等工艺参数对连铸结晶器内钢液行为的影响。     

浸入式水口结构对大方坯结晶器流场和温度场影响的数学模拟

利用Fluent软件针对南钢大方坯结晶器建立了三维有限差分模型,计算了连铸结晶器内的流场和温度场,分析了浸入式水口倾角和水口出口面积对结晶器内流场和温度场的影响。当浸入式水口倾角为10°时,大方坯结晶器流场和温度场分布较为合适;水口出口面高度为（18＋2×18）mm时,浸入式水口出口面积较合适。     

宽板坯连铸结晶器内钢液流动的数值模拟

结合水模型实验,应用商业软件Phoenies模拟230 mm×2 000 mm连铸坯结晶器内钢液流场。研究了浸入式水口底型、插入深度、出口倾角等工艺参数对钢液面波动及流股对结晶器窄面冲击力的影响,并用水模型实验进行验证。结果表明,合理的浸入式水口结构尺寸和工艺参数为:凹底结构、插入深度120 mm、倾角15°。     

中厚板表面夹渣缺陷分析与研究

通过对夹渣缺陷处夹杂物的扫描电镜分析,铸坯皮下夹渣的产生原因是结晶器流场不合理,保护渣随结晶器内钢液流动卷入铸坯所致。通过改进浸入式水口形状、尺寸,优化浸入式水口插入深度,优化结晶器保护渣理化指标等工艺措施,可以有效减少连铸坯夹渣类缺陷。     

板坯结晶器流场物理模拟及冶金效果研究

以安钢板坯连铸机结晶器为原型 ,进行了水力模型实验。实验包括流场显示、波高测量、冲击深度测量以及卷渣实验。研究了水口结构、浸入深度、拉速对结晶器流场的影响及其变化规律。这些结果对优化水口设计 ,提高产品质量和降低成本有重要作用。     

梅钢连铸板坯边裂的成因与对策

通过对梅钢炼钢厂连铸机板坯边裂的现场调查、测试和统计,分析了板坯边裂的成因,并提出了相应的对策,指出结晶器足辊变形、结晶器倒锥度不合适、结晶器内钢水偏流、结晶器角缝挂钢、浸入式水口参数及吹氩操作等是产生连铸板坯边裂的主要原因。     

Three-dimensional analysis of molten steel flow in slab continuous casting mould with rotated ports in submerged entry nozzle

Abstract

The purpose of this study is to develop a three-dimensional (3D) analysis system capable of analysing the flow field of molten steel in the slab continuous casting mould with rotated ports in the submerged entry nozzle. The ultimate goal is to obtain the optimal design for the entry ports of the submerged nozzle, which can introduce favourable flow patterns to remove non-metallic inclusions and avoid entrapment of molten slag and casting powder to produce steel slab of high cleanliness. In this study, a computational fluid dynamics technique, Sola-Surf, is employed to conduct the 3D fluid flow analysis. The technique has the capability of treating fluid flow problems with a free surface that slightly vibrates. The slightly vibrating free surface presents fairly accurately the behaviour of the molten slag–casting powder layer in the continuous casting mould. The developed simulation system is then tested on a slab continuous casting mould to analyse the fluid flow behaviour of molten steel under various nozzle designs. The design conditions include submerged depth of the nozzle, tilted angle of the nozzle port, and rotated angle of the nozzle port. The results of the simulations show that of the various design factors rotation of the nozzle entry ports has the greatest effect on the flow pattern. It can prolong the residence time of the molten steel and stabilise the molten slag–casting powder layer, which is very favourable for obtaining continuous casting slag of high cleanliness.     

结晶器保护渣试验条件探讨

介绍了影响结晶器保护渣试验效果的主要浇注工艺因素,对结晶器保护渣试验条件进行了探讨。试验时必须考虑钢水质量和温度、浇注液面的稳定性、水口插入深度及对中精度、保护浇注效果、氩气大小以及保护渣操作等各方面因素的影响。通过保护渣反复试验,不断调整保护渣理化指标和连铸机浇注工艺条件,保护渣性能才能不断满足工艺质量的要求。     

Slab quality improvement by controlling mould fluid flow

Abstract

Cleanliness of steel is a primary requirement for flat products. It is obtained with minimum of defects by controlling the liquid flow characteristics in the mould and fluctuations over the meniscus surface. Liquid flow in the mould region is due to the momentum of the pouring stream which in turn is related to the clogging of submerged entry nozzle and argon flow in the mould. This makes control of liquid steel flow dynamics in the mould important. The mould level fluctuation index, flow fraction or clogging percentage and optimised gas flow models have been developed and are correlated for minimised surface fluctuations throughout the casting sequence. Tundish weight, casting speed, casting section and immersion depth of the nozzle which primarily change the flow profile inside the mould are the key operational variables considered for model calculations. The operational parameters were adjusted to follow the developed models criteria for different casting conditions. Online application of these operational control models contributed to stabilise the mould fluid flow and have helped in decision making for pumping, flushing and tube changing. The present paper describes the mathematical approach adopted in calculation of optimum casting parameters for controlling flow of liquid steel, nozzle clogging and gas injection rate at JSW Steel Ltd. This has resulted in considerable reduction in mould level fluctuations and production of superior quality slabs even at higher casting speeds.