阳极表面能流密度(EFD)分布可以表征极间等离子体对阳极的加热作用,是重要的真空电弧特性参数。为此,在前期建立的真空电弧磁流体动力学(MHD)模型的基础上,引入边界条件,计算了小间隙中超音速电弧和亚音速电弧的阳极表面能流密度参数,并进一步分析讨论了电弧电流、触头开距、触头半径和纵向磁场(AMF)等燃弧参数变化对该参数的影响。研究结果表明:1)当电弧电流增大时,上述参数均增大,且向弧心收缩加剧,亚音速电弧收缩更加明显;2)当触头开距增大时,上述参数也向弧心区域逐渐收缩;3)当触头半径增大时,上述参数均逐渐减小,且沿径向分布越来越均匀;4)当纵向磁场增大时,上述参数的径向分布越来越平缓。上述燃弧参数变化对阳极表面能流密度的分布均有影响,因此,减小触头开距、增大触头半径和纵向磁场均能抑制阳极表面能流密度的收缩,减少输入阳极的能量,提高真空开关开断性能。
The energy flux density (EFD) on anode surface represents the heating effect of inter-electrode plasma on an anode, and it is an important characteristic parameter of vacuum arc. Therefore, using the previous magneto hydro dynamic (MHD) model of vacuum arc, we introduced the boundary conditions and numerically calculated the EFD of supersonic and subsonic arcs in short gaps. Then, we analyzed and discussed the influences of arcing parameters, such as arc current, contact gap length, contact radius and axial magnetic field strength (AMF), on the EFD in detail. The results show that, 1) as the arc current increases, the EFD not only increases but also constricts toward the centre of arc column; 2) as the contact gap length increases, the EFD also constricts toward the centre of arc column; 3) as the contact radius increases, the EFD decreases and distributes more homogenously along the radial direction; 4) as the AMF increases, the radial distribution of EFD is flatter. All the variations of arcing parameters have impacts on the distribution of EFD, thus the decrease of contact gap length and both the increases of contact radius and AMF will restrict the constriction of EFD, which will decrease the energy to flow into the anode and improve the breaking performance of vacuum circuit breaks.