直流埋弧炉内电弧等离子体流动与传热分析

Analyses of fluid flow and heat transfer of arc plasma in DC submerged-arc furnace

双电极直流埋弧炉的使用是一种生产氧化镁单晶的有效途径.为理解和优化电弧冶炼过程,建立了电弧炉中等离子体射流的三维稳态磁流体动力学模型.在模型中假设,电弧等离子体处于局部热动态平衡状态,而且熔池表面没有发生变形.利用ANSYS有限元分析软件,得到电弧温度场、流场、压力场和电势的分布.最后近似给出了由电弧引起的熔池表面等效热通量的分布.计算结果表明,熔池表面所受到的压强大小跟电流以及弧长有关:电流越大,压强越大;弧长减小,压强先增大后减小.

Using a twin-electrode DC submerged-arc furnace is an effective method for MgO single crystal production. A steady 3D magnetohydrodynamic model of the arc plasma jet is developed in order to provide detailed information for understanding and optimizing the production process of the electric arc furnace. It is assumed that the arc plasma is in local thermodynamic equilibrium and there is no deformation on the bath surface. The finite element-based analysis software ANSYS is applied to calculating the temperature, flow, pressure field and the potential distribution of the arc plasma. Lastly, the heat flux distribution on the surface of the bath is presented. The calculated results show that the arc pressure on the bath surface is significantly influenced by the current and the arc length. It is found that the pressure increases with the increasing of the current, and it increases first and then decreases with the decreasing of arc length.