【作者】 赵丽；

【导师】 任廷志；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2010， 硕士

【摘要】 在连铸过程中,对铸坯质量影响最大的部件就是结晶器,它素有“连铸机心脏”之称。国内外学者对结晶器内流场和温度场的研究一直比较关注。但多数的研究都是在不考虑凝固坯壳存在的情况下,对流场与温度场进行耦合求解,或是直接对流场与温度场进行非耦合求解。本文采用商用软件FLUENT中的凝固融化模块与二次开发相结合的方法,选择SIMPLE算法,较好地模拟出凝固坯壳和两相区对结晶器内流场温度场的影响。针对首秦公司的宽厚板坯连铸建立了结晶器内钢液流动、传热凝固的三维数学模型,计算得到了结晶器内钢液流场和温度场的分布规律。模型中将两相区处理为多孔介质,控制体的孔隙率和速度通过液相率来确定,并对凝固坯壳赋以拉坯速度,分析了凝固坯壳和糊状区对结晶器内钢液流场和温度场的影响。在考虑钢液凝固和糊状区孔隙率时,钢液的流动区域变小,钢液下回流区的涡心上移,其湍流特性明显增强。受下回流区涡流变化的影响,水口附近的液面波动也增大,同时流场的改变引起温度场的变化。因此,在进行结晶器流场温度场模拟时,必须考虑钢液的凝固,否则将影响计算结果。此外,本文还模拟分析了浸入式水口出口倾角、水口壁厚、水口出口面积比、浸入深度、拉坯速度、过热度对宽厚板坯结晶器内钢液流动方式、传热和凝固的影响。通过分析不同工况下的结晶器内温度场和凝固壳厚度分布情况,合理设计水口的结构参数和操作工艺,提高拉坯速度和铸坯质量,指导连铸生产。更多还原

【Abstract】 As the heart of slab conticaster, mould is the most important part of it. Many scholars, at home and abroad, pay more attention to the fluid flow and temperature distribution in slab continuous casting mold. But most of them simulate the process without regard to the influence of shell thickness and mushy zone. Or deal the heat transfer and the flow with segregated solver, The modeling solidification and melting of commercial FLUENT package and program designed is apply in this paper. The SIMPLE algorithm namely the Semi-Implicit Method for Pressure Linked Equations is employed to solve the equations. The flounce, because of the existence of shell thickness and mush zone, can be analyzed exactly.Based on the mould of continuous casting for manufacture of steel slab that made in Qinhuangdao Shouqin metallic material Co., Ltd., the flow and temperature fields are simulated. The mushy zone is treated as a“pseudo”porous medium with porosity equal to the liquid fraction, and velocity is attention to it too. Shell thickness’velocity is equal to pull velocity. Because of shell thickness and mush zone, the flow zone is smaller and vortex center is rising, and the characteristic of flow field is evidence. Compared the change above, the fluctuation on top is larger, where near the SEN. And the temperature filed also change. The fluid solidification should be considered when we solve fluid flow problems. Or it must be wrong.Furthermore, the research analyze the effect of outlet angle of SEN, thickness of SEN, the ratio of SEN’s outlet area to inlet, immersion depth of SEN, casting speed, superheat to flow field, temperature field and solidification in this thesis. Therefore, that simulating temperature distribution and shell thickness in mold under different working condition and design rational SEN and casting technology parameters will have useful guiding significance to the process of continuous casting.更多还原