板坯连铸水口内钢液流动的数值模拟

 运用CFX计算软件研究了大通钢量工况下板坯浸入式水口流场，分析了水口结构、结晶器流动控制方式、水口吹氩等对浸入式水口流场的影响。研究表明，适宜的水口结构和控流方式组合能获得最优的水口出口流股形态和稳定均衡的流场。在大通钢量下，塞棒、底部凸起水口结构是最佳组合。不适宜的工艺组合形成并加重水口偏流，造成结晶器初始坯壳的不均匀冲刷和液面涡流，进一步诱发水口堵塞、水口结瘤、结晶器非稳态和不均衡传热，最终导致铸坯缺陷甚至诱发拉漏事故。

Numerical Simulation of Steel Flow in Submerged Entry Nozzle for Slab Continuous Casting

Mathematical model such as CFX is a powerful tool for getting an insight into the production sequence of the steel. Mathematical model of fluid flow in submerged entry nozzle in high speed slab continuous casting shows that the bottom structure and the structure mode of flow switch are main factor affecting the outlet velocity values in the submerged entry nozzle, the unstabilization and non equilibrium velocities from the outlet of the submerged entry nozzle also affect velocity values in the mold, the bottom structure and the mode of flow switch structure are very important at high speed. Sliding gate and heave bottom structure and level bottom structure are availability for fluid flow in submerged entry nozzle in high speed slab continuous casting. If the bottom structure and the mode of flow switch structure are unsuitable, the asymmetric unbalance steel flow from submerged entry nozzle to mold, mold original slab shell non uniformity crash and surface vortex, and unbalance steel flow also cause nozzle clogging, unsteady and disequilibrium heat transfer in mold, and at last cause breakout and slag trapping and defect in slab.