板坯二冷区旋转型电磁搅拌的数值模拟仿真
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摘要
在二冷区进行电磁搅拌能够有效提高板坯质量,本文利用ANSYS和CFX商业软件,对板坯连铸二冷区旋转型电磁搅拌的电磁场和钢液流场进行了模拟研究。结果表明:在电磁搅拌辊附近,水平截面的中间磁场与左右两侧磁场方向相反;同向相邻电磁搅拌模式(搅拌模式I)产生一对左右基本对称的感应电流密度回流区;同向间隔电磁搅拌模式(搅拌模式II)和反向间隔电磁搅拌模式(搅拌模式III)均产生上下两对左右基本对称的感应电流密度回流区;在三种旋转型电磁搅拌模式下的搅拌辊附近的水平截面,磁场力和流场分布均类似;在搅拌模式I的条件下,板坯中心纵截面流场在电磁搅拌辊附近呈现先收缩后扩张的趋势;在搅拌模式II和III的条件下,板坯纵截面流场呈现收缩,扩张,再收缩,再扩张的趋势。
S-EMS(Strand Electromagnetic Stirring)is one of the effective measures to improve continuously cast slab quality. In the present work,commercial software ANSYS CFX was applied to simulate rotating electromagnetic field and the flow field in secondary cooling zone of a slab continuous caster equipped with SEMS. The simulation results show that,on the horizontal cross-section near the S-EMS rollers,the direction of the magnetic field in the middle region of the cross-section is opposite to that in both side regions of the cross-section. In the case of the same direction magnetic field induced by vertically closely adjacent S-EMS rollers(Stirring mode I),there are two nearly symmetric circulation zones in the induced current density field,whereas in the cases of the same and the opposite direction magnetic fields induced by vertically separated S-EMS rollers(Stirring modes II and III),there are two couples of vertically separated symmetric circulation zones in the induced current density field. The electromagnetic force field and the flow field on the horizontal cross-section near the S-EMS rollers are similar under all three S-EMS modes investigated. Furthermore,for the Stirring mode I,molten steel circulation flow on the central vertical cross-section first contracts and then expands,while for the Stirring modes II and III,the molten steel circulation flows on the central vertical cross-section exhibit a trend of first contracts,then expands,and then contracts and expands again.
S-EMS(Strand Electromagnetic Stirring)is one of the effective measures to improve continuously cast slab quality. In the present work,commercial software ANSYS CFX was applied to simulate rotating electromagnetic field and the flow field in secondary cooling zone of a slab continuous caster equipped with SEMS. The simulation results show that,on the horizontal cross-section near the S-EMS rollers,the direction of the magnetic field in the middle region of the cross-section is opposite to that in both side regions of the cross-section. In the case of the same direction magnetic field induced by vertically closely adjacent S-EMS rollers(Stirring mode I),there are two nearly symmetric circulation zones in the induced current density field,whereas in the cases of the same and the opposite direction magnetic fields induced by vertically separated S-EMS rollers(Stirring modes II and III),there are two couples of vertically separated symmetric circulation zones in the induced current density field. The electromagnetic force field and the flow field on the horizontal cross-section near the S-EMS rollers are similar under all three S-EMS modes investigated. Furthermore,for the Stirring mode I,molten steel circulation flow on the central vertical cross-section first contracts and then expands,while for the Stirring modes II and III,the molten steel circulation flows on the central vertical cross-section exhibit a trend of first contracts,then expands,and then contracts and expands again.
引文
[1]刘洋,王新华.二冷区电磁搅拌对连铸板坯中心偏析的影响[J].北京科技大学学报,2007,29(6):582-585,590.
[2]BIRAT J P,CHONE J. Electromagnetic stirring on billet,bloom,and slab continuous casters:state of the art in 1982[J]. Ironmaking&Steelmaking,1983,10(6):269-281.
[3]雷洪.结晶器冶金学[M].北京:冶金工业出版社,2011:8-25.
[4]杨卯生,赵爱民,毛卫民,等.钢的半固态电磁搅拌力场与组织转变[J].钢铁研究学报,2003,15(4):18-23.
[5]易军.基于旋转磁场、行波磁场电磁搅拌器的数值模拟[D].包头:内蒙古科技大学,2014:16-17.
[6]陈士富,王猛,牛宏,等.二冷区辊式电磁搅拌的模拟研究[J].辽宁科技大学学报,2017,40(5):337-342,349.
[7]任兵芝,朱苗勇,王宏丹,等.大方坯连铸结晶器电磁搅拌三维电磁场与流场的数值模拟[J].金属学报,2008,44(4):507-512.
[8]SZEKELY J. Fluid flow phenomena in metals processing[M]. New York:Academic Press,1979:175–203.
[9]YU H,ZHU M. Three-Dimensional magnetohydrodynamic calculation for coupling multiphase flow in round billet continuous casting mold with electromagnetic stirring[J].IEEE Transactions on Magnetics,2009,46(1):82-86.
[10]LEI H,ZHU M Y,HE J C. Mathematical and physical modeling of interfacial phenomena in continuous casting mould with argon injection through submerged entry nozzle[J]. Acta Metallurgica Sinica,2000,13(5):1079-1086.
[2]BIRAT J P,CHONE J. Electromagnetic stirring on billet,bloom,and slab continuous casters:state of the art in 1982[J]. Ironmaking&Steelmaking,1983,10(6):269-281.
[3]雷洪.结晶器冶金学[M].北京:冶金工业出版社,2011:8-25.
[4]杨卯生,赵爱民,毛卫民,等.钢的半固态电磁搅拌力场与组织转变[J].钢铁研究学报,2003,15(4):18-23.
[5]易军.基于旋转磁场、行波磁场电磁搅拌器的数值模拟[D].包头:内蒙古科技大学,2014:16-17.
[6]陈士富,王猛,牛宏,等.二冷区辊式电磁搅拌的模拟研究[J].辽宁科技大学学报,2017,40(5):337-342,349.
[7]任兵芝,朱苗勇,王宏丹,等.大方坯连铸结晶器电磁搅拌三维电磁场与流场的数值模拟[J].金属学报,2008,44(4):507-512.
[8]SZEKELY J. Fluid flow phenomena in metals processing[M]. New York:Academic Press,1979:175–203.
[9]YU H,ZHU M. Three-Dimensional magnetohydrodynamic calculation for coupling multiphase flow in round billet continuous casting mold with electromagnetic stirring[J].IEEE Transactions on Magnetics,2009,46(1):82-86.
[10]LEI H,ZHU M Y,HE J C. Mathematical and physical modeling of interfacial phenomena in continuous casting mould with argon injection through submerged entry nozzle[J]. Acta Metallurgica Sinica,2000,13(5):1079-1086.