吹氩钢包内气液两相流动及均混行为的数值模拟

Numerical simulation on fluid flow and mixing behavior in argon blowing ladle

气泡浮力是促使钢包内钢液循环流动的驱动力,正确理解吹气钢包内气液两相区结构是认识钢包内气液两相流的关键。比较了经典的准单相模型条件下钢包内的流场及含气率沿钢包径向和轴向的变化规律,通过与实际观测结果比较得知Castillejos模型与实际两相区结构相吻合。随后采用该模型分析了钢包浇铸过程中不同液面条件下钢液的均混行为。随着底吹气量的增加,钢包内钢液的均混时间逐渐缩短。相同底吹气量条件下,钢包内的熔池液面越浅,钢液的均混时间也越短,但当液面低于200 mm后变化规律相反,这主要是由于液面降低到一定液位时钢包内循环流减弱所致。研究结果对于系统理解钢包内的流动状态和均匀行为具有理论指导意义。

The fluid flow in argon blowing ladle is driven by buoyancy of bubble. In order to quantitatively describe the fluid flow phenomena, it is essential to understand the structure of argon- liquid zone. In the present paper a numerical model was built to research the velocity field, gas fraction distribution under different quasi-single phase flow models. The classical Castillejos model was used to study the mixing behavior during teeming process in ladle. With increase of gas blowing rate, the mixing time decreased. Under same argon blowing rate, as the free surface goes down the mixing time became shorter. Nevertheless, when surface level was lower than 200 mm, the variation law reversed, that was because the circulation flow became weaker at lower surface level condition. The results obtained in this paper could provide theoretical support for understanding the fluid flow and mixing behavior in ladle.