18板坯连铸结晶器内钢液流动控制的数学物理模拟研究8-28.docVIP

板坯连铸结晶器内钢液流动控制的数学物理模拟研究 王波1,2，张捷宇1，安胜利2，王周勇2，韩春鹏2 （1，上海大学 材料科学与工程学院，上海，200072；2，内蒙古科技大学 材料与冶金学院，内蒙古包头，014010） 摘要：控制结晶器内钢液的流动状态和液面的波动程度是提高钢液洁净度和改善板坯连铸坯质量的重要手段。本文根据Fr和修正Fr准数相似的原则，建立了一个1：2 的板坯连铸结晶器的水模型。利用激光多普勒测速仪、浪高仪等设备及计算流体力学方法研究了板坯连铸结晶器水模型内流体的流动形态和液面的波动状况。分析了连铸参数：拉速、吹气量、水口浸入深度、水口出口角度等对流动和液面波动的影响。根据研究结果给出了控制钢液流动的最佳操作参数。数值模拟结果和实验结果一致。 关键词：流体流动，液面波动，激光多普勒测速，数学模拟 MATHEMATICAL AND PHYSICAL SIMULATION OF CONTROLLING FLUID FLOW IN A SLAB CASTING MOLD WANG Bo1, 2, ZHANG Jieyu2, AN Shengli2, WANG Zhouyong2, HAN Chunpeng2 (1. School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China; 2. Material and Metallurgical School, Inner Mongolia University of Science and Technology, Baotou 014010, China) Abstract: Cleanliness of steel is a primary requirement for flat products. It is obtained with minimum of defects by controlling the liquid flow characteristics in the mould and fluctuations over the meniscus surface. A 1:2 scale water model of a slab casting mold was set up based on the criteria of Froude number and modified Froude number similarity. The fluid flow and level fluctuation in the water modeling were investigated by Laser Doppler Velocimeter (LDV), level sensor and CFD methods. The effect of casting speed, gas injection rate, immersing depth and port angle of submerged entry nozzle (SEN) on flow and level fluctuation were studied. Optimum casting parameters for controlling flow of liquid steel were obtained in this water modeling of a slab casting mold. The experimental results are used to validate steady-state numerical simulations with CFD method on the basis of the k-ε two equations model. The calculated results are generally in the consensus of the experimental data. Key words: fluid flow, level fluctuation, LDV, mathematical simulation 1 前言 在连铸生产过程中，结晶器是钢水成为产品的最后一道冶金工序，钢液在结晶器内的传输行为（流动、传热和传质行为）直接影响着最终产品的质量。其中，钢液在结晶器内的流动行为对于氩气泡和夹杂物的运动行为、自由表面的波动行为、弯月面凝固、凝固坯壳厚度、热应力变化、卷渣和裂纹形成等具有重要的影响。所以说，控制结晶器内钢液的流动状态是提高钢液洁净度和改善铸坯质量的重要手段。