共查询到18条相似文献,搜索用时 336 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
根据相似原理,针对某钢厂四流中间包建立1∶2.5的物理模型,模拟钢液在原包内的流动情况,并研究弧形开孔导流墙和弧形开槽导流墙对中间包内钢液流动的影响。水模实验结果表明,由于原包冲击区域较小,导致各流最小停留时间和峰值时间较小,死区比例较高,不利于连铸生产的顺利进行。中间包控流装置采用弧形开孔导流墙和湍流控制器优化后,中间包冲击区体积变大,对两端的控流能力增强,流体在中间包内的流动情况得到很大改善。优化后1、2流死区比例分别减少了12.3%、12.1%,平均停留时间分别提高39 s、52 s。 相似文献
9.
10.
11.
连铸中间包内夹杂物去除机理的水模型研究 总被引:2,自引:0,他引:2
通过选择乳状液滴模拟夹杂物和连铸中间包水模型实验,考察了控流装置、浇铸速度及夹杂物粒径对中间包内夹杂物去除行为的影响规律.结果表明:挡墙-挡坝组合控流去除夹杂物效果最佳,中间包内强湍流区夹杂物的碰撞、聚合以及向上和表面流速的增加是主因;中间包注流区加入冲击槽,虽然其流体流动特征发生改变,但对夹杂物去除率的影响并不显著;浇铸速度较高时,仅靠控流装置的优化已不能很好地改善夹杂物的去除效果. 相似文献
12.
13.
针对国内某特钢厂新上的四流H型双通道感应加热中间包,为改善中间包内流体流动状态,设计了倒八字型与V型两种控流装置。应用数值模拟的方法对两种不同控流装置下的中间包流场、RTD曲线、温度场进行了模拟。结果表明,倒八字型控流装置平均停留时间1 469.6 s,死区体积比5.83%,边部水口与中间水口的最大温差3 K;与V型控流装置相比,平均停留时间延长了41.9 s,死区体积相应降低了4.09%,边部水口与中间水口的最大温差减少了2 ℃。湍流抑制器+倒八字型控流装置设计能更好改善四流大方坯H型双通道感应加热中间包流体流动性。 相似文献
14.
针对中间包连铸过程中夹杂物的存在易导致铸坯出现质量缺陷的问题,以不锈钢连铸中间包为研究对象,通过数值模拟方法研究了控流装置、夹杂物密度以及夹杂物尺寸等参数对中间包内夹杂物去除行为的影响规律。研究结果表明,在设置堰坝和湍流控制器中间包内,密度为2 700 kg/m3,粒径为5 μm的夹杂物去除率为63.32%,而150 μm的大尺寸夹杂物去除率可达到89.04%。当夹杂物粒径为10~50 μm,密度为2 700~4 500 kg/m3时,夹杂物密度对夹杂物去除率影响较小。无控流装置中间包时,夹杂物在顶渣层呈以中心纵截面对称的分布;设置堰坝中间包时,挡渣堰坝两侧出现了70 μm以上夹杂物密集区;设置堰坝组合湍流控制器中间包时,夹杂物主要被限制在中间包第一腔室自由液面,研究结果对于进一步发挥不锈钢连铸过程中的中间包冶金功能具有指导意义。 相似文献
15.
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。 相似文献
16.
《中国铸造》2016,(6)
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. 相似文献
17.
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. 相似文献