半密闭灭弧腔室内电弧运动特性的三维仿真和实验

3D Simulation and Experiment Research on Arc Motion Characteristics in the Semi-Enclosed Arc-Extinguishing Chamber

在配网线路防雷中,利用多个半密闭灭弧腔室串联将长空气间隙电弧分段淬灭的多腔室灭弧结构因其优异的灭弧性能,受到学者的广泛关注。在应用于配网线路雷电防护时,多腔室灭弧结构中的气体间隙被击穿后,冲击电弧在半密闭灭弧腔室内的运动特性直接影响该结构的灭弧性能。为了研究冲击电弧在灭弧腔室内的运动特性,该文将气流场、流体传热场、电磁场多场全耦合,建立单个半密闭灭弧腔室内冲击电弧的三维数值仿真模型,分析电弧从腔室内运动到腔室外的动态演变过程;搭建冲击电流试验平台,利用高速摄像机拍摄了电弧从腔室内运动到腔室外的图像,分析电弧运动图像的特征。结果表明,仿真得到的电弧完全运动到腔室外的时刻和电弧完全熄灭的时刻与试验图像特征吻合,验证了仿真模型的准确性;得到了腔室内电弧温度、腔室内压强和气流速度随时间整体呈现先急剧增加后缓慢减小的趋势;当电弧电流为波形8/20μs、幅值2kA时,腔室内的电弧温度最高可达41000K,压强最大达2MPa,气流速度最大达3000m/s。

The multi-chamber arc-extinguishing structure,which uses multiple semi-enclosed arc-extinguishing chambers in series to quench long arc in sections,has been widely concerned by scholars because of its excellent lightning protection performance.When multi-chamber arc-extinguishing structure is broken down,the movement characteristics of high current impact arc in semi-enclosed arc-extinguishing chamber directly affect the arc-extinguishing performance of multi-chamber arc-extinguishing structure.In order to study the motion characteristics of the high current arc in the arc-extinguishing chamber,the three-dimensional numerical simulation model of the impact arc in a single semi-enclosed arc-extinguishing chamber is established by fully coupling the gas field,fluid heat transfer field and electromagnetic field,and the dynamic evolution process of the arc from the chamber to the outer space is analyzed.Then,the impact current test platform is built and image of the arc moving from the chamber to the outer space is photographed by high-speed camera.The results show that the time when the arc completely moves to the outside of the chamber and the time when the arc is completely extinguished are basically consistent with the experimental image characteristics,which verifies the accuracy of the simulation model;the arc temperature,pressure and air velocity in the chamber increase sharply at first and then decrease slowly with time;when the arc current is 8/20μs and the amplitude is 2kA,the arc highest temperature in the chamber is 41000K,the maximum pressure is 2MPa,and the maximum gas velocity is 3000m/s.