中间包温度场数值模拟

利用Fluent软件对马钢四钢轧的原中间包和改进后中间包的温度场进行数值模拟与比较.模拟结果表明,中间包的最大温差达12.08 ℃;对原中间包进行改进后,中间包内的温度场最大温差为7.32℃,明显优于原中间包.     

中间包流场数值模拟

利用大型流体计算软件Fluent,对马钢连铸中间包的流场进行数值模拟.将模拟计算结果与现有中间包存在的实际现象对比表明,中间包在现有结构条件下分流和控流装置获得的流场分布不利于中间包钢水中夹杂物的控制和去除.通过改变原有中间包挡墙结构,从而改变中间包内流场分布,彻底改变了中间包中的流型结构,延长了流体质点的运动轨迹,增加了钢液的平均停留时间,为微型夹杂物的去除提供了有利条件.     

基于RTD曲线连铸中间包优化设计数值模拟

为了优化连铸中间包内型,采用数值模拟方法计算钢液在连铸中间包内的停留时间分布（RTD）,并通过RTD曲线分析了连铸中间包内挡坝高度和位置对其钢液流场的影响。结果表明,结构优化后的连铸中间包钢液流场趋于合理,死区体积分数由原始方案的17.62%降至13.29%,且钢液在连铸中间包内的停留时间变化不大。     

CSP中间包内腔优化的数值模拟

针对CSP中间包内冶金过程,建立中间包内钢水流场、温度场、夹杂物运动的数学模型,对不同挡墙和挡坝的5种组合方案的中间包钢水,从流动、传热和去夹杂能力等方面进行分析。结果表明:不同挡墙和挡坝的组合方案中,方案5效果最佳,其结构合理,钢液停留时间有效延长,利于夹杂物的上浮;没有明显的低温区域,中间包出口与入口的温差为5℃;对50μm的夹杂物能去除98.4%,对40μm的夹杂物去除率达到92.3%。     

板坯中间包空包、充包过程中自由表面的数值模拟

中间包液面稳定时,钢水的流入和流出可以近似认为是一个稳定流动过程.然而在开浇时液面升高或在换钢包和浇注末期中间包液面下降时,流速有较大的变化而引起流动模式改变导致表面波的形成.研究了中间包内钢液在空包和充包过程中自由表面的变化以及此过程的速度场,研究结果深化了对中间包空包、充包工作过程的认识.     

柳钢中间包坝堰优化设计的计算机模拟与水力学模拟实验研究

应用计算机数值模拟和水力学模拟实验对柳州钢铁厂连铸中间包坝堰进行了优化设计,其优化设计研究结果对柳钢连铸生产具有指导意义。     

中间包自由表面的数学模拟

为了更好的发挥中间包在冶金中的作用,研究了坝高、堰深、坝堰间距及中间包水口出流速度等因素对中间包自由表面的影响,试验通过营造中间包水口附近平稳的钢液面来减少卷渣,从而达到提高铸坯质量的目的。     

板坯连铸中间包结构优化的研究

结合某公司双冲击点板坯中间包生产现状,利用水模实验对中间包内钢水流动特性进行了研究.结果表明：原中间包结构存在明显的短路流,钢水停留时间偏短,死区体积分率偏高,不利于夹杂物上浮去除.同时,由于在高度较大的两湍流控制器间钢水不能流出,影响金属收得率.这种具有双冲击点的中间包,应按照对称的两个单流板坯中间包进行结构优化.采用小高度湍流控制器加上下挡墙的控流方式时,由于钢水流经路径增长和全混流体积分率增加,响应时间增长,死区体积分率显著减小至15%以下,有利于夹杂物上浮去除.同时,将小高度湍流控制器和门式开孔导流坝相结合,残钢量显著减小,有利于提高金属收得率.     

漩流中间包流场的数值模拟

采用CFD软件Fluent对漩流中间包内的流场进行了数值模拟,分析了漩流中间包内的流场特征,以及漩流室的加入,中间包内的流动形态.模拟结果表明,由于漩流室的加入使湍动能耗散主要集中在漩流室内部,有利于夹杂物的聚合长大;漩流室的加入可改善钢液的流动状态,利于夹杂物的上浮。由于入口位置的非对称布置,造成了漩流中间包内的流场在入口区呈明显的非对称分布,这些结果为进一步优化漩流中间包内漩流室的位置和中间包挡墙参数提供了理论依据.     

Numerical simulation of flow phenomena and optimum operation of tundish

1　INTRODUCTIONDuringthecourseofcontinuouscastingsteel,theflowofliquidsteelintundishwasafairlycomplexprocesscontainingmomentumtransfer,masstransfer,energytransferandphase changeofmultiphasecomponents .Ac cordingtoRefs.[1,2 ],someinfluencingfactorsincastingsteelwerefound ,includingthecompositionofliquidsteel,thetechnicalparametersoftundishandre oxidationofmoltenmetal.Theprocesswouldaffectdirectlysurfacedefectsandinternalstructureformationofthecastingsteelproductsaswellastherealizationofhig…     

Design optimization of flow control device for multi-strand tundish

The fluid flow phenomena in tundish have a strong influence not only on the uniform of composition and temperature of bath, but also on the separation of non-metallic inclusions, especially for the multi-strand tundish. A water model of a multi-strand tundish has been set up based on the Froude number and Reynold number similarity criteria. The effect of dam+weir and baffle on the uniform of composition and temperature of bath for different nozzles has been studied. The residence time distribution curves of the fluid flow were measured by SG800. Comparing the photos of the flow pattern in tundish, the optimum arrangement of baf-fle+dam was obtained. This new structure is benefit not only to uniform the temperature among different SENs (submerge entry nozzles) but also to separate the non-inclusions from the liquid steel, it can be widely used in multi-strand tundish.     

中间包控流装置的物理模拟研究

根据相似原理,建立1∶3的物理模拟模型,通过正交试验考察了挡渣堰、导流坝组合控流装置对中间包流场的影响。研究结果表明,堰坝间距是影响流场的主要因素,优化控流组合方案为：挡渣堰距注入流中心线距离1 200 mm,挡渣堰下沿距包底距离500 mm,导流坝高度360 mm,堰坝间距300 mm.优化后中间包流场趋于合理,钢液在中间包内的停留时间延长,活塞流体积增大,死区体积减小.     

Validation of the numerical simulation of fluid flow in the continuous casting tundish

The 3-dimensional fluid flow in a water model of the continuous casting tundish is simulated with the k-ε two-equation turbulence model. The methods to decide the size of wall-adjacent grids and the effects of residuals and mesh size on the simulation accuracy are discussed. The current investigation concludes that the following condition should be satisfied to get accurate enough simulation results: (1) If the dimension of the domain is in the order of cubic meters, the average size of cells in the mesh system should be at least smaller than 30 mm; (2) The normalized non-scaled residual should be reached at least smaller than 10^-4.     

中间包控流装置对温度场影响的数值模拟研究

通过对六流连铸机不同控流装置中间包内钢液温度场的数值模拟,提出了采用导流隔墙的改进方案.这种导流隔墙的应用,有利于均匀钢液温度,促使夹杂物上浮.     

Water modeling of molten steel flow in a multi-strand tundish with gas blowing

Fluid flow characteristics in a four-strand tundish with gas blowing were studied by water modeling experiments.It is found that gas blowing can greatly improve the flow characteristics in the tundish with a turbulence inhibitor.It dramatically increases the peak concentration time,and greatly decreases the dead volume,and reduces the minimum residence time.The gas blowing location,gas flow rate,and porous plug area greatly influence the flow characteristics in the tundish;the gas blowing location near t...     

Mathematical modeling of fluid flow, heat transfer and inclusion transport in a four strand tundish

Mathematical simulation was used for trouble-shooting and optimization. By the mathematical simulation, fluid flow and beat transfer of molten-steel in a four-strand tundish of a billet caster under different conditions （bare tundish and tundish with flow control device） were analyzed, The results showed that （1） the tundish with flow control device （FCD） has an important effect on the fluid pattern and temperature distribution; （2） the unsteady, solving method was used to model the inclusion motions at different time perthds, and it showed that the FCD is advantageous to separate the nonmetallic inclusions. According to the simulation results, the main problem existing in the industry preduction was found, and some helpful rneasurements were executed. Consequently, the large nonmetallic inclusions were separated, and the content of total oxygen was reduced. The qualily of steel was greatly improved.     

Dissymmetric flow phenomenon in a multistrand tundish

The dissymmetric flow phenomenon exists in a symmetric multistrand tundish. It was studied by the physical simulation experiment. The fundamental flow characteristic of dissymmetry was analyzed. The asymmetry of the flow field, the temperature field, and the inclusions distribution without flow-control devices (FCDs) were compared with those with FCDs. It is proved that the asymmetry of the flow and temperature field along the outlets at the long range is more obvious. The symmetric FCDs installation has a slight effect on the dissymmetric temperature field, simultaneously, the symmetry of the average residence time and the fluid flow pattern has improved, and the fluid flow in the tundish has been more reasonable. In case of a symmetric multistrand tundish having a large volume, the influence of the dissymmetric phenomenon should be considered and the flow behaviors in the whole tun- dish should be studied completely.