摘要
为满足热防护测试中对测试设备的成本低、功率范围宽、持续运行时间长等要求,该文研发了一种双进气道空心电极结构的三相交流电弧等离子体炬,建立三维湍流磁流体动力学多物理场耦合仿真模型,得到了整个炬内电弧等离子体的流动状态和电-热特性,并揭示了进气量、工作电流、进气量分配比和工作频率对等离子体炬内多物理场分布和电弧特性的影响规律。研究表明,在进气量从30 g/s增大到60 g/s的过程中,壁面流动气体的冷却效应显著强于弧柱加热效应,使炬内温度呈下降趋势;电弧电压随着工作电流的减小、总进气量的增加和进气量分配比的增加而增大;电弧工作频率在1 kHz时比工频具有更稳定的运动趋势,弧根旋转速度更快,与电极接触面积变小,有助于提高电极寿命。仿真与实验结果对比误差均在8%以内,验证了所建模型的准确性。
The arc plasma torch can be used for pre experiments on ground erosion performance testing of spacecraft flight materials,which can save costs.The three-phase AC arc plasma torch has the advantages of simple power supply and reliable operation.The hollow electrode structure with dual inlet channels can not only improve the electrode life,but also achieve a wider range of power control.However,the design of plasma torches with this type of electrode structure is more complex and there is limited research and application in China.A three-phase AC plasma torch with magnetic motion,tangential inlet,and supersonic jet was developed and numerically modeled and experimentally studied.Firstly,a three-dimensional turbulent MHD multiphysics coupling simulation model of a hollow electrode three-phase AC arc plasma torch with a dual end inlet structure was established,and the flow state and electric thermal characteristics of the arc plasma inside the torch were obtained.Secondly,the influence laws of air intake,working current,air intake distribution ratio,and working frequency on the electric field,magnetic field,temperature field,flow field distribution,and arc characteristics inside the plasma torch were studied and revealed.Finally,the correctness of the numerical model was verified by comparing the arc voltage,nozzle outlet temperature,and arc root position under various operating conditions in simulation and experiment.The conclusion drawn from the study is as follows:(1)In a three-phase AC plasma torch,aerodynamic and electromagnetic forces dominate the flow characteristics of the arc root.During the process of increasing the intake volume from 30 g/s to 60 g/s,the cooling effect of the gas flowing along the wall is greater than the heat generated by the arc column,resulting in a downward trend in temperature;And the larger the intake volume,the more obvious the compression effect of the cold air layer on the arc,and the higher the arc pressure;The higher the working current,the higher the plasma temperature and jet velocity.(2)In a hollow electrode AC plasma torch with dual inlet ducts,changing the air intake distribution ratio can alter the position of the arc root along the electrode axis and the magnitude of the output power.Increasing the air intake distribution ratio can make the arc more significantly stretched in the axial direction,the arc longer,and the arc root closer to the arc back cover.(3)When the operating frequency is 1 kHz,the arc has a more stable motion trend,and the rotation speed of the arc root is five times that of the power frequency.The contact area with the electrode is reduced,which reduces the degree of electrode erosion and can improve the electrode life.
作者
宋竟绮
郝瑞祥
袁帆
周法
陈海群
Song Jingqi;Hao Ruixiang;Yuan Fan;Zhou Fa;Chen Haiqun(School of Electrical Engineering Beijing Jiaotong University,Beijing 100044 China;China Academy of Aerospace Aerodynamics,Beijing 100074 China)
出处
《电工技术学报》
北大核心
2025年第13期4125-4137,4179,共14页
Transactions of China Electrotechnical Society
关键词
空心电极
交流等离子体炬
三维电弧建模
电弧高频特性
Hollow electrode
AC plasma torch
3D arc modeling
high frequency characteristics of arc
作者简介
宋竟绮,男,1999年生,硕士,研究方向为交流等离子体炬建模与控制。E-mail:22121502@bjtu.edu.cn;通信作者:郝瑞祥,男,1975年生,副教授,博士生导师,研究方向为大功率电源、高频开关电源和电力电子变换器数字控制技术。E-mail:haorx@bjtu.edu.cn。
