圆坯连铸电磁旋流水口及电磁搅拌对流动及传热的调控机制

The control of flow pattern and heat transfer behavior of molten steel in mold could improve billet quality in continuous casting of steel. Mold electromagnetic stirring(M-EMS) could play a certain effect on improving billet quality. However, due to the skin effect and other factors, the stirring intensity has limitations. And because it is controlled by rotating at the outer field of mold, molten steel rotating in the centre is weak. The control of flow and temperature fields should be further improved. The swirling flow nozzle could make the molten steel rotate fast in the submerged entry nozzle(SEN), and promote uniformity and stability of the outflow, and drive the molten steel in the mold rotate, improve the flow and temperature fields in the center of the mold. But taking into account such factors as the strength of the nozzle, the intensity of electromagnetic swirling also has limitations. The advantages of the two technologies are developed to further improve the flow and temperature fields of molten steel in mold, and to improve the billet quality. Both mathematical model and physical model are used in this work. Based on round billet continuous casting process, regulation mechanism of electromagnetic swirling flow in the SEN and M-EMS on flow and heat transport is investigated to obtain optimum flow field, temperature field and the corresponding parameters. The work is to provide theoretical guidance and scientific basis for the actual production.

在连铸过程中，改善结晶器内钢液流动和传热行为，可以有效提高铸坯质量。结晶器电磁搅拌在此方面可以发挥一定的效果，但由于集肤效应等因素，搅拌强度受到一定限制。由于是由外及内的控制钢液旋转，内部钢液旋转较弱，在控制结晶器内流场、温度场方面还有待进一步提高。而电磁旋流水口，可以使钢液在水口内产生较强旋转，促进水口出流的均匀性和稳定性，并从中心处带动钢液在结晶器内旋转，改善钢液流场、温度场。但考虑到水口强度等因素，水口电磁旋流的强度也会受到一定限制。本研究希望发挥两者的优点，共同促进结晶器内钢液流场、温度场，提高铸坯质量。本研究采用数学模型和物理模型相结合的研究方法，依据圆坯连铸生产工艺条件，研究电磁旋流水口和结晶器电磁搅拌对钢液流动、传热行为的调控机制，获得较优的结晶器内流场、温度场及相对应的参数，为实际生产提供理论指导和科学依据。。

在连铸过程中，改善结晶器内钢液流动和传热行为，可以有效提高铸坯质量。结晶器电磁搅拌在此方面可以发挥一定的效果，但由于集肤效应等因素，搅拌强度受到一定限制。由于是由外及内的控制钢液旋转，内部钢液旋转较弱，在控制结晶器内流场、温度场方面还有待进一步提高。而电磁旋流水口，可以使钢液在水口内产生较强旋转，促进水口出流的均匀性和稳定性，并从中心处带动钢液在结晶器内旋转，改善钢液流场、温度场。但考虑到水口强度等因素，水口电磁旋流的强度也会受到一定限制。本研究希望发挥两者的优点，共同促进结晶器内钢液流场、温度场，提高铸坯质量。本研究采用数学模型和物理模型相结合的研究方法，依据圆坯连铸生产工艺条件，研究电磁旋流水口和结晶器电磁搅拌对钢液流动、传热行为的调控机制，获得了水口电磁旋流和结晶器电磁搅拌共同作用时结晶器内钢液流场、温度场的较优结果：水口顺时针旋转，结晶器电磁搅拌逆时针旋转。水口旋流参数为350A，50Hz，结晶器电磁搅拌参数为200A，4Hz。