Abstract: The fluid flow in the baths of a 120 t AOD converter and its water model with a 1/4 linear scale in the simple top blowing process have been modeled and predicted using the simple top blowing component of three-dimension mathematical model proposed for the flow of molten steel in an AOD bath under the condition of combined side and top blowing. The results show that this component can pretty well model the liquid flow in an AOD bath with simple top blowing. Under the action of a gas top blowing jet, two major circulatory flows with axial asymmetry forms in the bath and their eddy cores are respectively located at the near wall regions of the bath upper places on both sides of the central sunken pit of the liquid surface. The flow velocity and turbulent kinetic energy of the liquid are higher only near the surface of the sunken pit, at the surface layer of the bath, near the upper side wall and around the axis, and are all lower in the other zones of the bath. At a close or same gas blowing rate, the liquid flow velocity and turbulent kinetic energy during the simple top blowing are all much smaller than those during the simple side blowing.

Key words: stainless steel, AOD refining, combined side and top blowing, simple top blowing, liquid flow, mathematical modeling

摘要： 应用提出的侧顶复吹AOD熔池内钢液流动三维数学模型的纯顶吹分量，对纯顶吹下120 t AOD转炉及线尺寸为其1/4的水模型熔池内液体的流动分别作了模拟和估计. 结果表明，该模型的顶吹分量可相当好地模拟纯顶吹AOD熔池内液体的流动. 在顶吹气流作用下，熔池内形成两个非轴对称的主回流，其涡心位于液面中心凹坑两边熔池上部近壁区. 在纯顶吹条件下，液体流速和湍动能仅在凹陷面附近、熔池表层、上部近壁区和轴线周围较高，在熔池其余部位都较低. 在相近或相同的吹气量下，纯顶吹下液体的流速和湍动能都远小于纯侧吹下的相应值.

关键词: 不锈钢, AOD精炼, 侧顶复吹过程, 纯顶吹过程, 液体流动, 数学模拟