非对称中间包常用控流装置冶金效果的数值模拟

Metallurgical effects of commonly used flow control devices in asymmetric tundish

采用CFD数值模拟方法定性和定量化分析了不同结构湍流抑制器、导流隔墙及其组合在非对称三流中间包内的应用效果。针对连铸生产中钢包注流温度变化这一实际工况,探讨了不同控流方案的冶金效果。结果表明:当前常用的加檐湍流抑制器可以更好地降低中间包自由液面湍动能及钢液流速,但在改善非对称中间包流动特性与提高各流一致性方面并不具有明显优势。一种湍流抑制器T3组合2号导流隔墙控流方案可使包内死区比例较仅添加湍流抑制器T2时降低11.41%,活塞流比例增加15.49%,且各流一致性显著提高。此外,当中间包来流温度升高或降低15 K时,T3+2号导流隔墙方案较仅添加湍流抑制器T2而言,导流孔的引导作用使钢液保持指向表面的流动形式,既有利于钢水中夹杂物的上浮去除,也可提高这种非对称中间包中各流冶金效果的一致性。

CFD numerical simulation was adopted to qualitatively and quantitatively analyze the application effects of different structural turbulence inhibitors,diversion wall and their combinations in an asymmetric three-flow tundish.The metallurgical effects of different flow control schemes were discussed for the actual working conditions of ladle incoming flow temperature variation in continuous casting process.The results show that the application of a turbulence inhibitor with eaves can further reduce the turbulence energy and velocity at the free liquid surface,but it doesn′t show obvious advantage in improving the flow characteristics of asymmetric tundish and improving the consistency of each strand.The scheme of turbulence inhibitor T3 combined with No.2 diversion wall can reduce the ratio of dead zone in the tundish by 11.41%and increase the ratio of plug flow region by 15.49%compared to when only the turbulence inhibitor T2 is added,and the consistency of each strand of the tundish is significantly improved.Additionally,when the incoming flow temperature of the tundish increases or decreases by 15K,the scheme of T3+No.2 diversion wall keeps the molten steel flowing towards the surface by the guide hole compared with the turbulence inhibitor T2 only,which is beneficial to the floating up and removal of inclusions,and also can effectively enhance the metallurgical consistency of each strand.