红外与激光工程, 2017, 46 (9): 0917009, 网络出版: 2017-11-17
利用TDLAS技术的多点甲烷气体全量程监测
Multi-point full range monitoring of methane based on TDLAS technology
甲烷(瓦斯)浓度 可调谐半导体激光吸收光谱技术 全量程 微型吸收池 在线监测预警 methane concentration TDLAS full-scale micro absorption cell online monitoring and early warning
摘要
甲烷气体是一种对人体和环境有严重危害的气体, 特别在煤矿、天然气罐、气站和石油化工等安全生产领域, 对甲烷气体的泄漏监测至关重要。利用可调谐半导体激光吸收光谱技术(TDLAS), 选择1 653.72 nm波长作为甲烷气体直接吸收检测的中心波长, 使用微透镜设计了14 cm光程吸收池建立了一套浓度范围为0~100%全量程甲烷在线监测系统, 利用分束器分成多路对不同位置进行监测, 通过小波变换对吸收信号进行降噪处理, 提高信噪比, 使系统的最低测量极限达到335 ppm(1 ppm=10-6), 并将自行研制的多点全量程激光甲烷传感器与商用红外甲烷气体探测器进行对比实验, 结果表明: 该系统具有测量稳定性好、测量范围大、响应速度快、免调校、测量探头本征安全、低成本等优点, 完全有能力满足各行业的使用需求。
Abstract
Methane is a dangerous gas for humans and ambience, and methane gas leak detection is especially significant in colliery, petrochemical, gas tank zone, gas station as well as any other safe fields. The fundamental of Tunable Diode Laser Absorption Spectroscopy(TDLAS) was introduced, the center wavelength at 1 653.72 nm was selected for the absorption of methane detection. Also, a 14 cm optical path reflection cell with micro-lenses was designed. The on-line detection system was tested with the 0-100% methane. And also, it can be used to monitor different positions with a beam splitter. In order to improve the signal-noise ratio(SNR), wavelet transform was used to reduce noise of absorption signals. The detection limit was 335 ppm(1 ppm=10-6). A comparison results between the homemade multi-point full-range laser methane sensor and the commercial infrared gas detector were proved that the system has many advantages to meet the requirements of the majority of industry monitoring, such as: the good stability, full range, fast response, calibration free, safe latent, anti-electric magnetic interference, low cost etc.
李哲, 张志荣, 孙鹏帅, 夏滑, 罗渊敏, 庞涛, 董凤忠. 利用TDLAS技术的多点甲烷气体全量程监测[J]. 红外与激光工程, 2017, 46(9): 0917009. Li Zhe, Zhang Zhirong, Sun Pengshuai, Xia Hua, Luo Yuanmin, Pang Tao, Dong Fengzhong. Multi-point full range monitoring of methane based on TDLAS technology[J]. Infrared and Laser Engineering, 2017, 46(9): 0917009.