一种新型高效率微波等离子体炬  

A New Type of High-Efficiency Microwave Plasma Torch

作　　者：马长强 杨丰铭 朱铧丞 杨阳[1] 黄卡玛[1] MA Chang-qiang;YANG Feng-ming;ZHU Hua-cheng;YANG Yang;HUANG Ka-ma(College of Electronics and Information Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学电子信息学院,四川成都610065

出　　处：《真空电子技术》2021年第2期23-28,55,共7页Vacuum Electronics

基　　金：国家自然科学基金项目(61971295)。

摘　　要：微波等离子体具有无电极、电子密度大、电子温度高和能量效率高等优势,广泛应用于日常生活、能源、化工和材料等领域,但是目前微波等离子体装置作用距离短,效率低,因此等离子体在腔体中停留时间较短,很难发挥出更好的性能,限制了等离子体在工业领域很好的应用。本文提出了一种新型等离子体炬结构,电磁波通过波导馈入圆柱腔体,能量在圆柱腔体中心聚集,形成中心等离子体,再通过纵向叠加另一个圆柱腔体,形成同轴结构,进一步将能量耦合到上圆柱腔体,进而增大等离子体的体积和高度。本文基于有限元方法的电磁仿真建立了等离子体高效激发装置模型,通过模型仿真不断优化腔体的各尺寸参数,然后通过流体仿真模拟了管道内气体流动,最后搭建了微波等离子体实验系统,并分析了不同流速、不同功率、不同气体、不同进气孔数目、不同进气孔倾斜角度等对于等离子体形成的影响。实验结果表明,微波利用效率平均在90%以上,最好可达到99%;通入气体后,火焰最高可达到70 cm以上。Microwave plasma has the advantages of electrodeless, high electron density, high electron temperature, and high energy efficiency. It is widely used in daily life, energy, chemical industry and material fields. However, the current microwave plasma device has a short operating distance and low efficiency, so the plasma has a short residence time in the cavity, which makes it difficult to exert better performance and limits the application of plasma in industrial field. This paper proposes a new type of plasma torch structure. For which, the electromagnetic waves are fed into a cylindrical cavity through a waveguide, and the energy is concentrated in the center of the cylindrical cavity to form a central plasma;another cylindrical cavity is stacked longitudinally to form a coaxial structure, and the energy is coupled to the upper cylindrical cavity, thereby increasing the volume and height of the plasma. Based on the electromagnetic simulation of the finite element method, a model of the high-efficiency plasma excitation device is established. The dimension parameters of the cavity are continuously optimized through model simulation, and then the gas flow in the pipeline is simulated through fluid simulation. A microwave plasma experimental system is built, and the effects of flow rates, powers, gases, numbers and inclination angles of inlet holes on the formation of plasma are analyzed. The experimental results show that the plasma efficiency is above 90% on average, and the best is up to 99%;after the gas introduction, the maximum height of flame is more than 70 cm.

关 键 词：微波等离子体 大处理量 效率高 流体仿真 多物理场 

分 类 号：TN015[电子电信—物理电子学]