双谐振结构同轴微波等离子体炬调谐特性分析  

Analysis of Tuning Characteristics of Coaxial Microwave Plasma Torch with Bi-resonant Structure

作　　者：喻明浩 白锦旗 王伟[2] 胡宇喆 刘一凡 YU Minghao;BAI Jinqi;WANG Wei;HU Yuzhe;LIU Yifan(Key Laboratory of Manufacturing Equipment of Shaanxi Province,Xi'an University of Technology,Xi’an 710048;School of Mechanical and Precision Instrument Engineering,Xi’an University of Technology,Xi’an 710048)

机构地区：[1]西安理工大学陕西省机械制造装备重点实验室,西安710048 [2]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《机械工程学报》2024年第5期169-182,共14页Journal of Mechanical Engineering

基　　金：国家自然科学基金(12175177);陕西省机械制造装备重点实验室开放基金(JXZZZB-2022-04)资助项目。

摘　　要：在CO_(2)分解转化方面,微波等离子体装置因其具有高效、节能等优势,已成为实现碳中和目标的有效技术手段。然而微波类装置在使用时,通常需要调节谐振频率,才能高效稳定地工作。为了提高CO_(2)微波等离子体装置的能量利用效率和工作稳定性,探究了同轴谐振器的结构参数对调谐带来的影响,并提出了双变量调谐模式。首先,建立了同轴微波等离子体炬的物理模型和等效电路模型,分析了等离子体炬的放电强度与同轴谐振器轴向尺寸之间存在的相互联系;然后建立了不同放电状态下的电导率分布模型,并通过COMSOL仿真得到了对应分布模型下的端口反射系数S11与同轴谐振器的轴向尺寸之间的调谐曲线;最后将仿真结果与等效电路模型进行了对比验证,并分析了单变量调谐与双变量调谐的效果,以及双变量调谐模式的可行性及特点。研究结果表明,相较于单变量调谐模式,双变量调谐模式可以将|S11|平均提高5%~15%,并可在3/4波长内获得不同放电状态下的最小S11值(即最佳谐振状态),可以进一步提高装置的功率耦合效率,减小能量损失,从而提高CO_(2)分解转化效率。In terms of CO_(2)decomposition and conversion,microwave plasma devices have become an effective technical means to achieve the goal of carbon neutrality because of their advantages of high efficiency and energy saving.However,when microwave devices are used,they usually need to adjust the resonant frequency to work efficiently and stably.In order to improve the energy utilization efficiency and working stability of CO_(2)microwave plasma devices,this study explores the influence of the structure parameters of the coaxial resonator on tuning is explored,and a bivariate tuning mode is proposed.Firstly,the physical model and equivalent circuit model of the coaxial microwave plasma torch are established,and the correlation between the discharge intensity of the plasma torch and the axial size of the coaxial resonator is analyzed.Then,the conductivity distribution models under different discharge states are established,and the tuning curve between the port reflection coefficient S11 and the axial dimension of the coaxial resonator under the corresponding distribution model is obtained by COMSOL simulation.Finally,the simulation results are compared with the equivalent circuit model,and the effects of univariate tuning and bivariate tuning,as well as the feasibility and characteristics of bivariate tuning mode,are analyzed.The results show that compared with the univariate tuning mode,the bivariable tuning mode can increase|S11|by an average of 5%-15%,and the minimum S11 value(i.e.,the best resonant state)in different discharge states can be obtained within 3/4 wavelength,which can further improve the power coupling efficiency of the device,reduce the energy loss,and thus improve the CO_(2)decomposition and conversion efficiency.

关 键 词：同轴谐振器 等效电路 调谐 微波等离子体 

分 类 号：TH39[机械工程—机械制造及自动化] TH703[动力工程及工程热物理] TK09