共查询到19条相似文献,搜索用时 78 毫秒
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针对某厂三流异型坯中间包,建立了相似比为1∶2的水模型,使用F曲线对不同控流装置下的中间包流场特性进行分析与优化。实验内容包括原型控流装置、湍流抑制器无挡坝、湍流抑制器加挡坝组合。结果表明,原型中间包中部水口存在短路流,水口间流动的差异性较大,可能导致三个铸流的铸坯温度和洁净度不均匀,进而发生同炉次各铸坯质量稳定性差的问题。采用湍流抑制器无挡坝控流装置,湍流抑制器导流孔夹角为60°时,短路流出现在中部;导流孔夹角为86°时,无短路流,各流一致性变好;导流孔夹角为110°时,两侧水口出现短路流,各流一致性优于前两个角度。中间包的各流一致性与死区比例并无相关性,一致性良好的中间包流场,其死区比例并不一定小。优化后的中间包湍流抑制器导流孔夹角为110°,挡坝距离中间包中心2400 mm,中间包内无短路流,1#、2#水口一致性最佳,死区由17.89 %减小到9.67 %,减小率为11.25 %,F曲线标准差最大值由0.3减小到0.016。 相似文献
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以某钢厂的八流连铸中间包为研究对象,采用数值模拟方法对不同控流结构中间包内钢液流场进行了研究,并通过水模型实验和工业生产进行验证。模拟结果表明:ASF中间包内的挡墙和湍流器能够明显改善钢液的流动状态和温度分布,加上双坝后效果更佳,钢液的流动存在4个环流区,不仅增加了钢液的混合程度,而且中间包内钢液的温度分布更均匀且低温区较少。水模试验表明在空包中加入湍流器和挡墙能明显改善各流流动特性的一致性,且在其基础上加入双坝能进一步改善钢液的流动特性,与数值模拟结果一致,此外,工业生产也完全达到预期效果。 相似文献
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六流边铸中间包内钢液流动的数值模拟 总被引:1,自引:1,他引:0
计算机模拟仿真作为一种参数优化的有效工具,在过程冶金中的应用已越来越广泛。对六流连铸中间包内钢水流动进行了计算机模拟研究后发现,原中间包设计存在不足,提出了优化的设想。 相似文献
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通过采用水模拟和数值模拟分别对中间包不同结构进行全因素试验,研究了双挡坝结构对钢液流动行为的影响,着重探讨了不同类型的双挡坝中间包内钢液的流动状态和速度分布。结果表明:低坝应设置在高坝后,顶端钢液流速将减小29%,降低浇注末期发生卷渣的概率;低坝应与高坝流钢孔同高,钢液的平均停留时间可达到最大稳定值;高低坝距离差为40~160mm时,流体流动状态较稳定,低坝后无漩涡产生。分析认为:中间包入口区和出口附近均为强湍流状态,其他区域均为过渡流状态,入口区利于夹杂物的碰撞长大,应至少保证该区域长度大于中间包长度的1/4,出口区强湍流易产生大夹杂物导致水口堵塞,应控制在出水口附近0.25m的区域内。 相似文献
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以单流中间包停留时间分布曲线(RTD曲线)组合模型为基础,充分考虑中间包各流流量对流动特性的影响,提出一个适合多流中间包的RTD曲线分析模型。该模型使中间包各流所对应的短路流、活塞流、混合区及死区的体积分数之和为100%,有效避免了传统组合模型所导致的各流股对应区域的体积分数之和偏大(超过100%)的情况,使之符合客观物理现实。模型选用短路流、活塞流、混合区及死区体积分数的标准差,进行各流流动一致性判断。以此为理论依据,采用水模拟实验,结合正交设计实验方法,确定八流一体式中间包控流装置的最佳组合为:低孔挡墙+低挡坝+盆式湍流抑制器。 相似文献
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通过开展中间包控流装置布置的正交试验,研究了反应器结构对钢水流动行为的影响.着重探讨了不同尺寸中间包的控流装置布置规律及其对钢液流动行为和夹杂物去除的影响,定量化得到了双流板坯中间包控流装置布置与死区体积和结构影响因子D的关系.实验结果分析表明:中间包内部分活塞流体积不利于夹杂物去除,死区体积可准确反映钢液的洁净度水平;出水口抽吸作用对钢液流动行为影响较大,挡坝布置在距出水口1000-1300 mm时钢液流动形态较好,夹杂物聚集导致的水口结瘤率低至7.5%;0.0035<D<0.0085时,可获得板坯中间包在普通拉速下的流场特征与挡坝相对位置的关系;中间包内钢液与夹杂物的相对运动速度为大于6×10-5m·s-1时,夹杂物的上浮速度较大. 相似文献
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通过水力学模型试验确定了非对称5流中间包最佳挡墙方案,并使用数值模拟研究了中间包内流场及温度场分布规律。研究表明,优化后中间包内温度场及流场稳定均匀,各流水口处钢水平均温差由原4流包的2.5℃降低到1.3℃;投入使用后,各流铸坯夹杂物评级小于2.0级,各流内部组织一致,铸坯质量良好,满足了生产需要和产品质量的要求。 相似文献
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ABSTRACTEffect of a swirling flow SEN (submerged entry nozzle) outlet design on the multiphase flow and heat transfer in a mould was investigated by using numerical simulation. It was found that different SEN outlet designs could form different flow patterns and temperature distributions on the upper of the mould. The enlarged outlet SEN design had an effect to decrease the horizontal velocity of liquid steel flowing out the SEN outlet, reducing the steel flow velocity towards the solidification front. Although a higher velocity was found near the slag/steel interface with the enlarged outlet SEN, but the turbulent kinetic energy was lower. The reason was that less circulation flows were formed in the region of the mould top. The weak horizontal flow towards the solidification front with the enlarged outlet SEN induced lower wall shear stresses, at the same time it also formed a lower temperature distribution near the solidified shell. 相似文献
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原型中间包结构不合理,两个水口进出口温差不一致,且包内温降较大.优化后中间包温度分布更加合理,进出口温差减小,最低温度有所提高,尤其方案3效果最佳. 相似文献
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The internal structure of continuous casting tundish is complex, and the flow state of molten steel is diverse. Detailed and accurate information of molten steel flow field is the premise of tundish control and optimization. Numerical simulation method has been widely used in the study of molten steel flow field in tundish. The accurate numerical simulation of molten steel flow field is inseparable from the appropriate turbulence model and the corresponding boundary conditions. Based on the CFD open source code OpenFOAM v8, three different types of turbulence models (standard k-ε model, RNG k-ε model, and SST k-ω model) were applied to simulate the molten steel flow in the tundish. Additionally, two boundary conditions of symmetry plane and the free slip were also applied. Comparing the simulation results to the experimental data, it shows the RTD curve obtained by the simulation with the SST k-ω model can successfully predict the "double peaks" that appeared in the experiment. Besides, the response time and peak value time are closest to that of experimental results. For SST k-ω, when changing the type of liquid surface boundary from free slip to symmetrical plane, the error of tracer response time obtained is reduced from 93.89% to less than 8.35%, and the error of peak time is reduced from 100.78% to about 12.32%. It can be concluded that the SST k-ω model and the symmetry boundary are applicable for the simulation of molten steel flow in the tundish. 相似文献