【作者】 潘宏伟； 程树森；

【Author】 PAN Hongwei,CHENG Shusen (School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)

【机构】 北京科技大学冶金与生态工程学院；

【摘要】 关于多流中间包流动特征的数学模型的研究甚少。如果引用由Sahai提出的针对单流中间包流动特征的数学模型来分析多流中间包流动特征,在一定条件下,计算得到的多流中间包内各区域的体积分数不合理:(1)计算出各流股对应的死区体积分数之和可能超过100%;(2)计算得到的死区体积可能为负数,这在实际中是不可能的;没有明确提出绘制RTD曲线的标准,致使国内外学者对该问题认识不统一;模型中没有考虑到短路流,无法计算其在中间包内的体积分数,但短路流对中间包冶金效果有很大影响;对于活塞流体积分数的计算也没有反映其本质特征。本文尝试提出了计算多流中间包内活塞区、返混区、死区和短路流区域体积分数的数学模型,通过计算结果分析多流中间包内流体的流动特征。新模型中提出了绘制RTD曲线的标准及其相关计算的规范;明确了"死区"的特性,提出了新的计算方法;考虑到了短路流,提出了计算短路流的方法,新模型可以同时计算出活塞流区域、返混流区域、死区和短路流的体积分数;新模型可以刻画实际流动方式与理想活塞流流动方式的偏差,能够体现出活塞流的流动特性。更多还原

【Abstract】 research about mathematical model for multi-strand tundish is few.If Sahai’s model,which is used for the case of single-strand tundish,is applied to calculate different regions’ volume fraction in multi-strand tundish,the calculation results of different regions’ volume fraction could be unreasonable in some cases:(1) the sum of each strand’s dead region’s volume fraction is bigger than 100%;(2)and the value of dead region’s volume fraction may be calculated to be minus,and all of these don’t agree with reality.What’s more,Sahai’s model does not propose the standard of plotting the residual time distribution curve (RTD-curve),and this makes scholars around the world can’t achieve consensus of views about it.The model doesn’t consider the bypass flow and can’t calculate its volume fraction,but bypass flow is critical to tundish metallurgy.Then a new model is attempted to propose in this paper.In the new model,the standard of plotting RTD curve is definitely proposed,and relative calculation method is also proposed;and the feature of dead region is carefully studied,and the model proposes a new method to calculate its volume fraction,and the calculation formula about its volume fraction can be adjustable according the actual demand; what’s more,the new model considers the bypass flow and proposes a method to calculate its volume fraction,and then volume fraction of plug flow region,backmix flow region,dead region and bypass flow can be calculated and obtained at the same time; and this new model can capture the difference between reality flow pattern and ideal plug flow pattern,and reflects the feature of plug flow.更多还原