基于多通光声池的SF_(6)分解产物H_(2)S的高灵敏度检测技术  

High-sensitivity Detection Technology of SF_(6)Decomposition Product H_(2)S Based on Multi-pass Photoacoustic Cell

作　　者：马凤翔 赵跃 王楠 赵新瑜 郭珉 李辰溪 朱太云 杭忱 陈珂 MA Fengxiang;ZHAO Yue;WANG Nan;ZHAO Xinyu;GUO Min;LI Chenxi;ZHU Taiyun;HANG Chen;CHEN Ke(Electric Power Research Institute,State Grid Anhui Electric Power Co.,Ltd.,Hefei 230601,China;School of Optoelectronic Engineering and Instrumentation Science,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]国网安徽省电力有限公司电力科学研究院,合肥230601 [2]大连理工大学光电工程与仪器科学学院,大连116024

出　　处：《光子学报》2023年第3期258-267,共10页Acta Photonica Sinica

基　　金：国家电网有限公司总部科技项目(No.B31205210011);国家自然科学基金(Nos.62275040,61905034)。

摘　　要：针对H_(2)S气体在近红外波段的吸收系数低导致检测灵敏度难以提高的难题,提出了基于共振式多通光声池的SF_(6)分解产物H_(2)S气体检测技术。对赫里奥特型多通光声池进行优化设计,激光光束反射次数达到20次。近红外激光经功率放大后入射到多通光声池,通过多次光学反射大幅度提升了光声信号的激发效率,结合声学共振放大技术、光纤放大技术和波长调制-二次谐波检测技术,搭建了一套光声光谱气体检测系统,实现了SF_(6)背景下微量H_(2)S气体的高灵敏度检测。实验结果表明,归一化噪声等效吸收系数为2.23×10^(-9)cm^(-1)·W·Hz^(-1/2),在平均时间为100 s时,该检测系统对H_(2)S气体的检测极限达到2.7×10^(-8)。SF_(6)is applied as an insulating medium in gas-insulated equipment due to its excellent insulation and arc extinguishing properties.However,aging or overheating within the equipment can cause partial discharge,resulting in the decomposition of SF_(6)to form low-fluoride compounds,which react with water and oxygen inside the equipment to produce the characteristic gas H_(2)S.As a decomposition product of SF_(6),H_(2)S is one of the characteristic components of fault diagnosis of gas-insulated equipment,and has strong corrosivity and toxicity.The inferior nature of this gas can lead to serious damage inside the equipment.Therefore,high-sensitivity online monitoring of trace H_(2)S gas is of great significance for the stable operation of gas-insulated equipment.Detection techniques for SF_(6)decomposition products envelop nonoptical and optical methods.Beer-Lambert-based Photoacoustic Spectroscopy(PAS)sensing technology is an indirect absorption spectroscopy technique that has gained a wider range of attention than non-optical detection methods due to its advantages of no gas load,no maintenance,fast response time,and high sensitivity.When the concentration of the gas to be measured is unchanged,the excitation light efficiency of the photoacoustic signal can be enhanced by increasing the length of the absorption path.The excitation light injected into the multi-pass cell is collimated by the collimator and reflected back and forth between the concave mirrors installed on both sides of the buffer of the photoacoustic cell.H_(2)S has a good spectral line absorption peak in the near-infrared band.The near-infrared laser is incident on a multi-pass photoacoustic cell after power amplified,and the excitation efficiency of the photoacoustic signal is greatly improved through multiple optical reflections.Combined with acoustic resonance amplification,optical fiber amplification and wavelength modulation-second harmonic detection technology,a set of photoacoustic spectroscopy gas detection system is built to achieve high-s

关 键 词：气体绝缘设备 SF_(6)分解产物 H_(2)S气体检测 光声光谱 多通光声池 

分 类 号：O433.5[机械工程—光学工程]