顶旋型湍流抑制器优化中间包流场的物理模拟  

Physical simulation on optimization of flow field in a tundish by top-swirling turbulence inhibitor

作　　者：王家辉 张华[1,2] 方庆[1,2] 周家朝[1,2] 谢旭琦 倪红卫 WANG Jia-hui;ZHANG Hua;FANG Qing;ZHOU Jia-chao;XIE Xu-qi;NI Hong-wei(Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China;Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金新工艺湖北省重点实验室,湖北武汉430081

出　　处：《钢铁》2023年第2期72-82,共11页Iron and Steel

基　　金：国家自然科学基金资助项目(52004191);中国博士后科学基金资助项目(2022M711120)。

摘　　要：设计了一种顶旋型湍流抑制器,使中间包冲击区内钢液在其作用下产生旋转的速度场,从而削弱钢液回流至钢-渣界面的强度,降低湍动能,避免卷渣和钢液二次氧化,以达到在冲击区内净化钢液的目的。通过水模型试验对比分析了无湍流抑制器、普通湍流抑制器和顶旋型湍流抑制器下单流中间包稳态浇注、开浇和换钢包时的多相流动行为,验证所设计的顶旋型湍流抑制器在中间包各操作阶段的优越性。结果表明,顶旋型湍流抑制器对中间包稳态浇注过程无负面影响,对非稳态浇注过程有明显改善效果。与不使用湍流抑制器相比,可以使钢液的平均停留时间由308.5 s延长至327.4 s,死区体积分数由9.67%减小至4.13%,响应时间由69 s增加到109 s,有效避免了短路流的出现。不采用湍流抑制器和采用普通湍流抑制器的中间包在开浇充包50 s后会分别产生115 cm^(2)和55 cm^(2)左右的钢液裸露,在换钢包过程再充包20 s后会分别产生90 cm^(2)和50 cm^(2)左右的钢液裸露,而采用顶旋型湍流抑制器均不会产生钢液裸露现象,且相较普通湍流抑制器可以有效降低开浇换钢包过程中钢-渣界面的液面波动幅度。顶旋型湍流抑制器可以有效改善钢液的流动状态,避免非稳态浇注时的卷渣及钢液二次氧化,提高钢液洁净度和金属收得率,且在不明显增加成本的前提下确保较高的使用时效,有较高的推广及应用价值。A top-swirling turbulence inhibitor(TI)was proposed to generate a rotating velocity filed of molten steel in the tundish impact zone,which could effectively weaken the strength of molten steel returning to steel-slag interface,reduce the turbulent kinetic energy,avoid slag entrapment and secondary oxidation of molten steel,so as to purify the molten steel in the impact zone.To validate the metallurgical superiority of the designed top-swirling TI in each tundish operation periods,the multiphase flow behaviors in a single-strand slab tundish during steady-state casting,start-up operation and ladle changeover process with different TIs(without a TI,with an ordinary TI and with a top-swirling TI)were compared and analyzed by water model experiments.The results showed that the top-swirling TI had no negative effect on the flow field at steady-state casting of tundish,while revealed obvious metallurgical advantages at the transient casting periods.Compared with the case of without a TI,when using the top-swirling TI,the average residence time of molten steel was prolonged from 308.5 s to 327.4 s,and the volume percent of dead zone was reduced from 9.67%to 4.13%,and the response time was increased from 69 s to 109 s,which would effectively avoid the occurrence of short-circuit flow.The exposed areas of molten steel under the cases of without TI and with ordinary TI were about 115 cm^(2)and 55 cm^(2)during start-up operation,and the exposed area were about 90 cm^(2)and 50 cm^(2)during ladle changeover,respectively.While the molten steel would not be exposed to air when using the designed top-swirling TI during both start-up operation and ladle changeover process,and it could effectively reduce the fluctuation of the steel-slag interface compared with the ordinary TI.The top-swirling TI can effectively improve the flow state of molten steel in the tundish,avoid slag entrapment and secondary oxidation of molten steel during transient casting periods,improve the steel cleanness and metal yield,and ensure remarkable service

关 键 词：中间包 湍流抑制器 水模型试验 非稳态浇注 开浇 

分 类 号：TF777[冶金工程—钢铁冶金]