直流电弧对工业硅埋弧炉内传热过程影响的数值模拟

Numerical Simulation of DC Arc Influence on Heat Transfer in Industrial Silicon Submerged Arc Furnace

为优化直流埋弧炉工业硅冶炼过程,建立二维轴对称等离子体电弧的磁流体动力学模型,运用有限元分析软件,计算得到了等离子体电弧的形态特征分布,并与已有的实验测量结果进行了比较。通过计算不同电流、弧长条件下电弧的温度、速度变化以及熔池表平面的热通量组成分布,分析了电弧的形态变化规律和电弧的传热方式,由此计算不同电流值、不同电弧弧长的条件时,电弧向阳极熔池表面传热的效率。结果表明:弧长越长,向熔池表面传热的效率越小;电流越大,向熔池表面传热的效率越高。基于结果分析,工业硅生产应采用长电弧低电流高电压的冶炼模式。

In order to optimize the process of silicon smelting in the DC submerged arc furnace,a twodimensional axisymmetric magnetic hydrodynamic（MHD）model of plasma arc was established based on the software of finite element analysis.The distribution of morphological characteristics of the plasma arc was obtained,andwas compared with experimental data.By calculating the change of arc temperature,arc speed and the distribution of the thermal flux over the surface of molten bath were analyzed under the different current and arc length,the morphological changes regularity and the heat transfer of arc were analyzed.Thereby,the heat transfer efficiency of the arc on the anode of the bath surface was calculated under thesame conditions as above.The results show that：the longer of the arc,the lower the heat transfer efficiency can be obtained;and the larger of the electric current,the higher efficiency is shown.Based on this analysis,it is concluded that the melting pattern of industrial silicon should be long arc,low current and high voltage.