基于双楔形扫描镜的甲烷气体光谱成像方法  

Methane gas spectral imaging method based on dual wedge scanning mirrors

作　　者：王夏春 张志荣 蔡永军 孙鹏帅 庞涛 夏滑 吴边[2] 郭强 Wang Xia-Chun;Zhang Zhi-Rong;Cai Yong-Jun;Sun Peng-Shuai;Pang Tao;Xia Hua;Wu Bian;Guo Qiang(Science Island Branch,Graduate School of University of Science and Technology of China,Hefei 230026,China;Anhui Provincial Key Laboratory of Photonic Devices and Materials,Anhui Institute of Optics and Fine Mechanics,Hefei Institute of Physical Science Chinese,Chinese Academy of Sciences,Hefei 230031,China;Key Lab of Environmental Optics&Technology,Anhui Institute of Optics and Fine Mechanics,Hefei Institute of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;Advanced Laser Technology Laboratory of Anhui Province,National University of Defense Technology,Hefei 230037,China;PipeChina General Academy of Science&Technology,Langfang 065000,China)

机构地区：[1]中国科学技术大学研究生院科学岛分院,合肥230026 [2]中国科学院合肥物质科学研究院安徽光学精密机械研究所,光子器件与材料安徽省重点实验室,合肥230031 [3]中国科学院合肥物质科学研究院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,合肥230031 [4]国防科技大学,先进激光技术安徽省实验室,合肥230037 [5]国家管网集团科学技术研究总院分公司,廊坊065000

出　　处：《物理学报》2024年第11期145-154,共10页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2022YFB3207601,2021YFB3201904);国家自然科学基金(批准号:11874364,41877311,42005107);中国科学院合肥研究院“火花”基金(批准号:YZJJ2022QN02);安徽省教育厅优秀青年科学基金(批准号:2022AH020098)资助的课题。

摘　　要：随着我国油气管道铺设数量的增加,对管道的维护工作也需予以更多的重视.目前,在油气输送站场内,主要采用人工巡检、对射式和云台式检测设备来检测天然气泄漏.但是这些方法存在响应度差、检测区域受限、泄漏点定位较慢等问题.为了满足对油气管道泄漏实时监测和快速定位的需求,本文设计了一种快速、精确控制的双楔形扫描镜系统,结合可调谐半导体激光吸收光谱技术,使得气体测量由原来的点测量转换为面测量.通过反解迭代优化算法,控制楔形镜的转角获得高效均匀的光束扫描轨迹,并将激光束的偏转方向及检测位置与对应的甲烷浓度信息相融合,构建了包含有位置信息的甲烷浓度数据,实现甲烷气体的光谱成像.实验中为了定量验证测量准确度及空间分辨率,通过标准气袋模拟甲烷泄漏分布,结果表明系统的成像浓度检测限小于500 ppm·m(1 ppm=10^(–6)),位置分辨率小于6 cm.同时该方法可以依据油气站场的测量距离调节扫描步进节点,从而实现成像分辨率的可调节,该成像方法为精确定位甲烷气体泄漏提供了新的思路.With the increase in the number of oil and gas pipelines laid in China,more attention needs to be paid to pipeline maintenance work.At present,the main methods of detecting natural gas leaks in oil and gas transmission stations include manual inspections,opposing natural gas detection equipment,and cloud desktop natural gas detection equipment.Hand held natural gas detection equipment is used for manual inspection,which requires regular manual inspection.However,the response speed is poor and gas leaks cannot be detected in a timely manner.The opposed laser gas detection method can only detect the presence of gas on the beam path.If a larger area of leakage detection is desired,more equipment needs to be installed,resulting in a greatly increase in hardware costs.The existing cloud desktop laser gas detection method controls the deflection of the laser beam through the cloud platform to achieve leak detection at various points in the area to be tested.However,the rotation speed of the cloud platform is slow,and a complete detection cycle takes dozens of minutes,and only the presence of gas can be detected.For accurate leak location,manual on-site survey is also required to further determine the leak location.In order to meet the needs of the real-time monitoring and rapid positioning of oil and gas pipeline leaks,in this work,a fast and accurately controlled dual wedge scanning mirror system is designed,which combines tunable semiconductor laser absorption spectroscopy technology to convert the gas measurement laser beam from point measurement to surface measurement,thereby obtaining the two-dimensional distribution of gas,which is conducive to subsequent analysis and positioning of gas leakage sources.By using the inverse solution iterative optimization algorithm,the angle of the wedge mirror is controlled to obtain an efficient and uniform beam scanning trajectory.The deflection direction and detection position of the laser beam are fused with the corresponding methane concentration information,and a methane co

关 键 词：激光吸收光谱 甲烷气体检测 双楔形扫描镜 气体成像 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]