数值模拟开式水冷模铸机浇注过程

Numerical simulation on teeming process of open water-cooling mold casting machine

以南钢开式水冷模铸机为研究对象,建立了型腔内钢液三维非稳态流动、传热和液面波动的数学模型,研究了浇注过程中钢液的流动特征、温度分布以及注流卷吸气体的运动规律。结果表明:浇注过程中,在"气体卷吸"作用下,型腔内钢液的流动存在显著差异,浇注前期表现为上升流呈多个大小不一的涡旋流,浇注后期则呈典型的逆时针涡旋流,并充满整个模腔。在该流动行为影响下,型腔内钢液温度场表现为中心低四周高的系列等温带,钢液表面水平流速随液面高度的上升而增加,在液面高度为3.1m时达到最大表面流速0.6m/s,此时液面波动大,易发生卷渣和钢液二次氧化。

In order to investigate the fluid flow,heat transfer and bubble entrainment with steel stream in the open water-cooling mold at different time,a three-dimensional unsteady model of liquid steel flow,surface fluctuation and temperature distribution in the mold was developed based on the open water-cooling mold casting machine of Nanjing Iron and Steel Co.,Ltd.The results show that the bubble entrainment has an important effect on liquid steel flow pattern in mold.The upward liquid steel flow is formed with several vortex zones of various sizes at the early teeming stage,while flow vortex is counterclockwise in whole mold under bubble flotation flow at the later teeming stage.The temperature field of liquid steel in mold presents an isothermal area whose temperature is lower in center and higher around the center.Liquid steel surface horizontal velocity increases with increasing the surface height.As the height of liquid steel surface rises up,the surface velocity of liquid steel increases,and the maximum value is 0.6m/s at the height of 3.1m.It is easy to cause slag entrapment and re-oxidation because of the large fluctuation of liquid surface.