考虑空气对流换热的弓网电弧仿真研究

Simulation study of bow net arc considering air convection heat transfer

为了更精确地研究电弧的温度分布特性,提出一种考虑空气对流换热的弓网电弧放电模型。该模型基于磁流体动力学原理,添加对流换热项修正热平衡方程,通过COMSOL软件多物理场仿真得到了弓网电弧温度分布,并使用PG 2000型光谱仪通过Boltzman法验证了750 V下电弧中心5 mm处的温度,平台测量结果与模型计算结果基本一致,验证了模型的可靠性。研究结果表明:电弧柱区域内温度最高点出现在电弧柱中心距接触线表面1.42 mm处,并随着电压的提升高温区域不断向阴极扩散;空气流动速度的提升可以加快电弧的散热,避免其形成热集中区域碳滑板表面温度远高于接触线表面,其温度差为4160 K,表面温度随材料热导率的增大持续升高。

In order to study the temperature distribution characteristics of the arc more accurately,an arc discharge model is proposed for the bow-net considering convective heat transfer of air.The model is based on the magneto-hydrodynamic principle,and the heat balance equation is modified by adding a convective heat transfer term.The arc temperature distribution of the arc is obtained by COMSOL multi-physics field simulation,and the temperature at 5 mm from the centre of the arc at 750 V is verified by Boltzman method using a PG 2000 spectrometer.The results show that the highest temperature in the arc column area occurs in the centre of the arc column at 1.42 mm from the surface of the contact line,and with the increase in voltage the high temperature area continues to spread to the cathode.The increase in air flow rate can accelerate the heat dissipation of the arc,avoiding the formation of a thermal concentration area carbon slip surface temperature is much higher than the surface of the contact line,the temperature difference is 4160 K,the surface temperature increases with the increase in thermal conductivity of the material continues to rise.