八流小方坯连铸中间包的数值模拟

针对八流小方坯连铸T形中间包,利用钢水流动、传热、传质的三维数学模型对其控流方案进行优化设计,对比分析不同控制装置下的钢水流场、温度场和停留时间分布(RTD)特征。研究结果表明:无控流装置时,中间包内存在短路流,死区较大,流动很不均衡,近流与远流的钢水停留时间和温度都相差较大;现用控流方案消除了短路流,减小了死区,但流动均衡性基本没有得到改善;优化方案比现用方案有了进一步的改善,各流停留时间相近,温差大幅减小,流动均衡性大大改善。     

非对称五流圆坯连铸中间包水模实验研究

采用水模实验研究了控流装置对非对称五流圆坯连铸中间包内流场的影响.通过测定模型中间包内各水口的RTD曲线,计算了中间包流场的平均停留时间及死区、活塞区和混合区的体积.提出了控流装置的开孔位置、大小、角度和布置方式对多流连铸中间包流动特性的影响规律.提出了能够合理分配钢水和有效减小死区的控流装置结构.     

四流大方坯连铸中间包结构优化水模实验研究

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。     

两流非对称中间包结构优化与应用研究

采用水模型实验、数值模拟相结合的方法分析了原型中间包和优化中间包在钢流流场、中间包流动特性方面的差异.结果表明:优化中间包2#水口平均停留时间延长了8.0%,两水口流体平均停留时间之差下降了36.3%.流体在优化中间包内流动轨迹更加复杂,延长了流体在中间包内停留时间.通过工业实验证实了优化方案的可行性.工业试验表明:采用圆形湍流控制器加单挡墙组成控流装置的原型中间包,两水口钢液平均温差为5℃,浇注得到的钢坯试样中,140~300μm夹杂物数量为0.7 mg;而采用非对称长方形湍流控制器加多孔挡墙组成控流装置的中间包,两水口钢液平均温差为3℃或2℃,约为原型中间包两水口钢液平均温差的1/2;浇注得到的钢坯试样中,140~300μm夹杂物数量为0.2 mg,约为原型中间包的1/3.说明采用非对称长方形湍流控制器加多孔挡墙组成控流装置的中间包对两水口温度的均一性起到了显著作用,且更能有效地去除钢液中的夹杂物.     

五流大方坯连铸中间包的水模型实验研究

通过水模型实验对苏钢五流大方坯连铸中间包现状进行了流体流动的模拟研究,发现了存在问题并提出改进方案。结果表明：五流中间包通过设置合理的控流装置（坝/墙）后,中间包内钢水的最小停留时间大大增加,峰值浓度时间和平均停留时间均增大,死区体积分率下降明显。     

薄板坯连铸中间包内抑湍器的模拟研究

控制中间包内钢液的合理流动对夹杂物的排除有重要影响,为此建立了模拟薄板坯连铸中间包流动情况的水模型。通过测定停留时间分布(RTD)曲线,研究了不同组合控流装置对中间包流体流动特性的影响。结果表明,结构及尺寸合理的抑湍器能延长水口响应时间及平均停留时间、提高活塞流区体积分数及降低死区体积分数;抑湍器与单坝组合的控流装置在控制流体流动方面效果极佳,而抑湍器与单墙单坝、单墙双坝组合的控流装置的控流效果不太理想。     

薄板坯连铸中间包流场数理模拟研究

控制中间包内钢液的合理流动对夹杂物的排除有重要影响，为此建立了模拟薄板坯连铸中间包钢液流动情况的模型。采用数学和物理模拟的研究方法，研究了不同尺寸和安装位置的控流装置对某钢厂薄板坯连铸中间包流动特性的影响。结果表明：中间包在无流动控制时，存在明显的短路流及较大死区；原使用控流装置其平均停留时间小，死区较大，实验效果并非最佳；通过实验提出的优化方案，使中间包内示踪刑开始响应时间为无控流装置下的2倍多，平均停留时间由264秒增加到301．4秒，死区由无控流装置的25．54％降低到15．39％，中间包的冶金性能有了明显改进。     

钢包长水口形状对中间包内钢液流动特性的影响

通过物理模拟实验研究了在不同的中间包液位时使用喇叭形长水口和直通形长水口对单流板坯中间包内的流体流动特性的影响.实验结果表明:使用喇叭形长水口后的RTD曲线峰值较低,波动较小,流场较稳定,而且不存在短路流;使用喇叭形长水口后更有利于延长流体在中间包内的开始响应时间、平均停留时间和活塞流平均停留时间;中间包内的死区体积较小,活塞流体积较大,而且活塞流与死区体积的比值也更大.因此,在中间包液位上升时,使用喇叭形长水口后包内的流动模式组成更合理,这更有利于保证中间包内钢水的质量.     

薄板坯连铸中间包控流装置的数理模拟

采用水力学数理模拟的方法,研究了不同尺寸和安装位置的控流装置对马钢薄板坯连铸中间 包流动特性的影响。结果表明：中间包在无流动控制时,存在明显的短路流及较大死区;西马克公司提供的控 流装置其平均停留时间小,死区较大,实验效果并非最佳;改进后的优化方案使中间包内示踪剂开始响应时间 为无控流装置下的2倍多,平均停留时间由264.0s 增加到301.4 s,死区由无控流装置的25.54%降低到 15.39%,中间包的冶金性能有了明显改进。     

板坯连铸38 t扩容中间包控流装置优化的数值模拟和应用

通过数值模拟,对钢厂250 mm×2 000 mm板坯连铸原29 t扩容至38 t中间包进行控流装置优化。研究了挡墙、挡坝的个数和位置对中间包内钢液流场及停留时间分布(RTD)曲线的影响,综合考虑了中间包冶金效果及生产成本,为现场提出了稳流器+挡墙+挡坝控流装置的最优设计方案,该方案使中间包活塞区比例达到77.1%,死区比例降至4.2%。现场采用该结构后非稳态浇铸期间生产的管线钢非金属夹杂物合格率由88%提高到95%,明显提高了中间包的冶金功能。     

25t连铸中间包流场优化水模试验研究

以相似原理为基础,用水模拟钢液研究中间包内的钢水流动特征,通过测定模型中间包内液体的停留时间分布曲线(RTD),计算其平均停留时间及死区、活塞区和混合区的体积。试验表明,经过改进的中间包,其最短停留时间由17s增加到33s,死区体积比则由12.68%降低到7.64%,优化了中间包内的流场。     

Flow Control in Six-Strand Billet Continuous Casting Tundish With Different Configurations

A 1∶2.5 scale tundish model was set up in laboratory for a six-strand billet continuous casting tundish with different configurations to investigate fluid flow characteristics under different operational conditions by measuring residence time distribution curves.It was found that minimum residence time,maximum concentration time and average residence time of the three strands on the same side of the tundish with the former configuration under normal operation,that is,six strands were open,were small and non-uniform and the tundish had large dead volume fraction.Vortexes easily formed on the liquid surface in the pouring zone of the tundish.The fluid flow characteristics in the tundish with the optimal turbulence inhibitor and baffles were improved and became less non-uniform among the strands.Vortexes were not found on the pouring zone surface in the optimal tundish.For non-normal operation,that is,one strand was close,it was important to choose which strand to be closed for maintaining flow characteristics of the rest two strands.It was found from this investigation that fluid flow characteristics in the optimal configuration tundish with closing strand 2 were better than those with closing strand 3 on the same side.     

五流非对称结构中间包流动及传热特征数值模拟

为优化某钢厂非对称结构中间包内流体流动、均匀各流钢液温度、延长近水口平均停留时间,以达到提高铸坯质量的目的,对工厂原方案及两个优化方案进行流场、温度场及停留时间的数值模拟计算.结果表明无控流装置的原中间包流动及温度场分布不合理,优化方案有了明显的改善,并确定了最佳方案.     

不同挡墙挡坝组合对两流中间包内流场的影响

在相似理论的基础上,通过水力学模拟对两流板坯连铸中间包3种不同挡墙挡坝组合形式下包内流场进行研究.试验结果表明:方案1(挡墙-挡坝-端挡坝方案)挡墙与挡坝间距不合理,端挡坝未起到控流作用致使中间包内流体平均停留时间、峰值时间短,死区比例较大(27.9%);方案2(挡坝-挡墙-端挡坝方案)显著改善了中间包内流场状况,全混流区及活塞流区比例增加,死区减小为21%;方案3(双墙双坝方案)由于增加一组挡墙延长了流体流动的路径,流体在中间包内的停留时间明显增加,死区比例最小(16.7%),同时微观电导率波动值也最小(0.025 ms/cm),为3种方案之最优.     

Flow Control in Six-Straud Billet Continuous Casting Tundish With Different Configurations

 A 1:2.5 scale tundish model was set up in laboratory for a six-strand billet continuous casting tundish with different configurations to investigate fluid flowing characteristics under different operational conditions by measuring residence time distribution curves. It was known from the investigation that minimum residence time, maximum concentration time and average residence time of the three strands in the same side of the tundish with the former configuration under normal operation, that is, 6 strands were open, were small and non-uniform and the tundish had large dead volume fraction. Vortexes easily formed on the liquid surface in the pouring zone of the tundish. The fluid flow characteristics in the tundish with the optimal turbulence inhibitor and baffles were improved and became less non-uniform among the strands. Vortexes were not found on the pouring zone surface in the optimal tundish. Under un-normal operation, that is, one strand was close, it was important to choose which strand should be closed for flowing characteristics of the rest two strands. It was found from this investigation that fluid flowing characteristics in the optimal configuration tundish with closing strand 2 were better than those with closing strand 3 at the same side.     

非对称控流结构中间包流场一致性的物理模拟

国内某钢厂使用的两流板坯连铸中间包因受固定位置排渣口的限制,包内控流装置采用左右不对称布置。生产实践发现,排渣口侧的水口对应铸坯大型夹杂物含量高、热轧卷探伤合格率低,疑与中间包流场的一致性有关。为此,采用1∶3.5的水模型对中间包流场进行了模拟研究,并基于流体动力学原理对其控流效果进行了优化。结果表明,原型中间包两个水口的滞止时间差高达36 s,钢液在排渣口侧的1号水口形成短路流,因而导致两流铸坯洁净度的差异。经水模优化后,方案F1下两流平均停留时间标准差和滞止时间标准差分别可降到0.12和0.35 s,明显改善了中间包内两流浇铸流动特性的一致性,且死区比例较原型降低8.87%、平均停留时间延长了30 s。     

Numerical Investigation of the Fluid Flow in Continuous Casting Tundish Using Analysis of RTD Curves

 A detailed mathematical procedure of the optimization of the fluid flow in a tundish water model with and without flow control devices (weir and dam) was carried out using the commercial CFD code FLUENT 60. The (k ε) two equation model was used to model turbulence. The residence time distribution (RTD) curves were used to analyze the behavior of the flow in tundish. The location of flow control devices in the tundish was studied. The results show that the flow modifiers play an important role in promoting the floatation of nonmetallic inclusions in steel. Comparing the three geometric configurations that are considered (bare tundish, weir, weir+dam), the tundish equipped with the arrangement (weir+dam) is a best and optimal geometric configuration of tundish.     

板坯连铸中间包流场及传热特征模拟研究

对某钢厂现有板坯连铸中间包进行流场模拟研究。研究结果表明：原结构的中间包内钢水停留时间短，死区体积大。通过优化设计使流场得以改善，并用数学模拟的方法进行了流场及传热特征计算，验证了通过水力学模拟试验得到的优化方案的合理性。     

Flow Characteristics and Inclusion Removal in a Ten-strand Continuous Casting Tundish:Physical Modelling and Industrial Trials

The flow characteristics and inclusion removal in a ten-strand continuous casting tundish were investigated with physical modelling and industrial trials.The results show that,among the strands,the strand with the mini-mum dimensionless time of the first appearance of tracer at the tundish exit appears to be the worst one for inclusion removal,while the strand with the maximum dimensionless mean residence time shows the best inclusion removal efficiency.The inclusion number decreases with increasing inclusion size for all strands.The inclusion number distri-bution among strands is the same for all inclusion sizes and the descending order of inclusion number is basically con-sistent with the ascending order of dimensionless mean residence time among individual strands.However,when the strand with the minimum dimensionless time of the first appearance of tracer at the tundish exit is not the same one with the minimum dimensionless mean residence time,the former seems to be inferior to the latter for inclusion re-moval.