连铸机中间包结构优化及流场分析

以六流T型中间包为分析模型,运用ANSYS软件的CFX模块进行中间包流场的数值模拟分析。考察了六流T型中间包在没有控流装置和在布置不同控流装置情况下的钢液流动特性。对于促进夹杂物在中间包内很好的上浮,提高连铸钢水的纯净度,并为在中间包内设置堰、坝结构的确定与否提供了选择的最佳方式。     

优化高拉速板坯连铸中间包控流装置的水模型和数值模拟

通过建立模拟高拉速板坯连铸中间包内钢液流动的水模型和数值模拟,研究了挡渣墙、坝和抑湍器等控流装置对中间包内流体流动特性的影响.结果表明,有无冲击板对中间包流动特性的影响不大,抑湍器与单墙双坝的合理搭配对中间包内夹杂物有效去除的流动特性十分重要,否则会起负面影响.提出了一个控流结构优化设计的方案.     

多流T型中间包流场和温度分布模拟研究

针对6流和8流T型连铸中间包内钢液的流动情况建立了数学模型,采用FLUENT商业软件计算了两种构造的中间包内钢液的流动状况和温度分布情况。比较不同出口之间钢液流速和温度分布的差异,研究结果显示8流中间包和6流中间包的温度场和速度场分布大致相同,但两种中间包内各出口的温度差却存在较大差异,8流中间包的最大温差较6流中间包大2 ℃。通过研究确定了有利于发挥中间包冶金功能的中间包设计方案,为中间包的设计优化和现场生产提供了理论依据。     

T型五流非对称连铸中间包内控流装置优化的水模拟实验

通过T型五流非对称连铸中间包水模拟实验,研究了控流装置对中间包内流体流动的影响。结果表明,结构合理的控流装置能够明显改善中间包内流体的流动特性,优化得出了中间包内控流装置的设计方案,为中间包内控流装置的设计提供了参考。     

四流方坯连铸中间包结构优化

在实验室建立了4流中间包流体流动的物理模型,通过测定停留时间分布(RTD)曲线,研究不同的控流装置组成的中间包结构对流体流动特性的影响。研究结果表明:沟槽或者圆孔槽均能明显改善各流流动特性的一致性,与带"V"型挡墙组合的挡坝高度对中间包内钢液的流动特性有影响;适当高度的坝与湍流控制器、沟槽、"V"型挡墙组合的控流装置在控制流体流动方面效果较好,在其基础上将沟槽改成圆孔槽控流效果更佳。根据实验研究提出最佳方案,即带湍流控制器、孔径φ150mm的"V"型挡墙、高300mm的坝和圆孔槽的中间包组合。     

八流中间包内控流装置结构的数理研究

针对某钢厂8流无控流装置中间包,应用物理和数值模拟方法进行了控流装置的优化研究.数值计算获得的结论与物理模型实验结果相吻合.使用优化的控流装置,利于夹杂物的上浮去除,延长了钢液在中间包内的平均停留时间,有效减小了各流间的停留时间差和钢液温度差,死区体积由48.2%下降至5.6%,中间包内流体的流动特性得到改善.     

方坯连铸机中间包流场流动特性研究

利用物理模拟的方法研究了十流方坯连铸机中间包内钢液的流动特征。通过研究不同控流装置对中间包流动特性的影响规律,提出了中间包内液态金属夹杂物去除的最佳控流方案,并将该控流方案应用于实际工业现场。现场试验结果表明,所开发的控流方案可将铸流温度差控制在5℃以内;相比原控流方案,可使液态金属夹杂数量降低大约26%,大于50μm的夹杂数量降低大约59%,大幅度提高了铸坯质量。     

基于恒过热控制的感应加热中间包内钢水的流动与传热

通过建立电磁-热-流动耦合数学模型,研究了一种六流H型通道感应加热中间包内电磁力的作用特点、钢水的流动及传热规律。对比了感应加热不同应用模式下中间包内流场和温度场特点,探讨了传统冷态水模拟研究方法对该感应加热中间包结构优化的适用性。结果表明,感应加热中间包通道内电磁力呈偏心分布,方向指向通道偏心位置,钢液在通道内旋转流出。裸包方案下,开启感应加热1500 s时比未开启中间包内1号水口处钢水温度高22 K;由于电磁力作用使通道附近水口的短路流加剧、各流一致性变差。但中间包结构优化后,通道附近水口短路流消失,各流温差降低、一致性改善、升温速率加快。模型研究结果揭示了这种新型中间包的冶金机理,同时也表明基于冷态模拟的中间包结构优化方法仍可作为感应加热中包结构设计和优化的重要依据。     

加设控流装置的T型五流非对称中间包流动特性数值模拟研究

基于某炼钢厂非对称五流连铸中间包的技术改造,采用数值模拟技术对加设控流装置的连铸中间包内部速度场和温度场进行模拟计算,得到钢液停留时间分布(RTD)曲线.通过对无控流装置和加设控流装置的对比分析研究表明:设置合理的控流装置位置、小孔直径和开口方向的控流装置,能够明显改善中间包内的流动特性,使钢液的分配均匀,降低了死区的比例,有利于夹杂物的去除.     

4流中间包钢液流动行为研究

通过水模型试验对4流方坯中间包在不同控流装置下包内流体流动动行为进行研究。研究结果表明：原中间包由于流体流速快导致边部流和中部流的流体特性差异大且死区比例高。改进后的中间包的边部流和中部流间的流体特性趋于一致,最小停留时间仅相差1~2 s;实际平均停留时间平均增加145.9 s,死区比例平均减小17.2%。     

Mathematical model of flow characteristic in multi-strand continuous casting tundishes

In this paper,the subject of mathematical model is a series of math expressions,which is used to calculate different regions volume fraction and analyze flow characterization in multi-strand tundish.But research about mathematical model for multi-strand tundish is few,and so far,there has been no acknowledged math model for multi-strand tundish to describe its flow characteristic.If Sahai s model,which is originally proposed for the case of single-strand tundish(proposed in reference[10],and this model is w...     

基于F曲线的多流非对称中间包死区计算模型

为了解决组合模型计算多流非对称中间包不同出口的停留时间分布曲线时出现的体积死区分率为负或结果偏差较大的问题,通过把“脉冲刺激-响应”试验所得的E曲线转换为F曲线,建立了基于F曲线的多流非对称中间包整体死区比例分析模型,并通过比较各流出口F曲线的差异量以及差异量极大值、最大值评价了多流非对称中间包钢液流动一致性。应用该模型对四流非对称中间包流场进行分析,水模型试验结果表明,无控流装置的中间包在3号、4号水口上方存在流动缓慢的区域,中间包钢水更新缓慢,流场不合理。增加挡墙后,中间包钢水流动一致性增强,2号、3号水口流动一致性相近;1号、4号水口流动一致性相近。使用挡墙+挡坝2的组合,各流一致性最好,死区比例最小。     

8流一体式方坯中间包控流装置优化研究

针对多流中间包冶金过程存在的问题,通过水模型试验,就影响其流场的因素,采用正交试验的方法对中间包内部控流装置进行优化。综合考虑各种影响因素,钢厂8流一体式T型中间包内合理的控流装置是带导流孔的V型挡渣墙+双坝的组合。     

Optimization of flow control devices in a tenstrand billet caster tundish

The physical model of a ten-strand billet caster tundish was established to study the effects of various flow control devices on the melt flow. Before and after the optimization of the melt flow, the inclusion removal in the tundish was evaluated by plant trials. The physical modeling results show that when combined with a baffle, the turbulence inhibitor, instead of the impact pad, can significantly improve the melt flow. A turbulence inhibitor with a longer length of inner cavity and without an extending lip at the top of the sidewall seems to be efficient in the improvement of the melt flow. Various types and designs of baffles all influence the flow characteristics significantly. The "V" type baffles are better than the straight baffles for flow control. The "V" type baffle with four inclined holes at the sidewall away from the stopper rods is better in melt flow control than the one with one inclined hole at each sidewall. The combination of a well-designed turbulence inhibitor and an appropriate baffle shows high efficiency on improving the melt flow and an optimal proposal was presented. Plant trials indicate that, compared with the original tundish configuration in prototype, the inclusions reduce by 42% and the inclusion distribution of individual strands is more similar with the optimal one. The optimal tundish configuration effectively improves the melt flow in the ten-strand billet caster tundish.     

Optimization of flow control devices for a T-type five-strand billet caster tundish: water modeling and numerical simulation

The optimization of flow control devices(FCDs) for a T-type five-strand billet caster tundish was carried out by water modeling and numerical simulation. In water modeling experiments, flow characteristics of the bare tundish and tundish conf igurations with designed U-type baff les and a round turbulence inhibitor were analyzed using residence time distribution(RTD) curves. Mathematical models for liquid steel in the real plant tundish were established using the fluid dynamics software package Fluent. The flow field, the temperature field, and the RTD curves of liquid steel in the proposed tundish conf igurations were obtained. The results of numerical simulation and water modeling were validated with each other by the predicted and experimental RTD curves. The results of flow field and temperature field were used to ref lect the actual state of a real plant tundish and to choose the optimal FCD. Finaly, from the whole performance of the multi-strand tundish, the optimal scheme was determined by combining the results of water modeling and numerical simulation. With the optimal tundish equipped with U-type baffle with def lector holes and round turbulence inhibitor, not only was the flow characteristic of each strand improved, but also the difference of flow characteristics between multiple strands was smaller.     

多流中间罐防下挠装置的设计开发与应用

通过对多流中间罐在连浇生产过程中发生下挠变形原因的机制分析,针对该现象,经过理论分析、现场调研以及技术交流,在中间罐车上设计开发了一种新型结构装置。该设计装置的应用可有效地解决中间罐的下挠变形问题;满足多炉连浇的生产要求;大大降低中间罐耐材的使用成本;为企业创造可观的经济价值。     

多流中间包流场模拟研究及优化

为了减少多流中间包的卷渣概率、提高对夹杂物的去除能力,采用物理模拟及数值模拟的方法对某钢厂六流中间包内部流场特性进行分析和优化。研究表明,导流孔仰角对中间包内流场及温度场有较大影响。改进后的挡墙使用25°仰角导流孔使各流最大温差由5.2 ℃降至2.4 ℃。较小的导流孔仰角对夹杂物去除有利,25°的仰角各流均匀性较好。提高挡坝高度亦有利于夹杂物上浮,推荐的挡坝高度为650 mm。另外建议现场浇注高度保持在100 mm以上以消除卷渣现象的不利影响。     

Optimization of lfow control devices in a ten-strand billet caster tundish

The physical model of a ten-strand bilet caster tundish was established to study the effects of various lfow control devices on the melt lfow. Before and after the optimization of the melt lfow, the inclusion removal in the tundish was evaluated by plant trials. The physical modeling results show that when combined with a baflfe, the turbulence inhibitor, instead of the impact pad, can signiifcantly improve the melt lfow. A turbulence inhibitor with a longer length of inner cavity and without an extending lip at the top of the sidewal seems to be efifcient in the improvement of the melt lfow. Various types and designs of baflfes al inlfuence the lfow characteristics signiifcantly. The “V” type baflfes are better than the straight baflfes for lfow control. The “V” type baflfe with four inclined holes at the sidewal away from the stopper rods is better in melt lfow control than the one with one inclined hole at each sidewal. The combination of a wel-designed turbulence inhibitor and an appropriate baflfe shows high efifciency on improving the melt lfow and an optimal proposal was presented. Plant trials indicate that, compared with the original tundish conifguration in prototype, the inclusions reduce by 42% and the inclusion distribution of individual strands is more similar with the optimal one. The optimal tundish conifguration effectively improves the melt lfow in the ten-strand bilet caster tundish.     

中间包传热边界对钢液流动及传热计算的影响

以某厂T型中间包为例,建立了中间包内钢液流动、传热数学模型。针对数值模拟中存在的传热边界条件的准确性问题进行探讨,引入了中间包包衬散热计算模型,得出关于中间包包衬结构的热流散失与内壁温度的关系,作为中间包内钢液流动、传热计算的边界条件。利用商用Fluent软件模拟计算,并比较分析了不同边界条件对中间包内钢液流动、传热的影响,结果表明提出的边界条件模型法使计算模拟结果更符合实际。