复杂山区铁路隧道红外激光甲烷遥测技术研究  

Study on Infrared Laser Methane Telemetry in Complex Mountain Railway Tunnel

作　　者：付伟[1] 黄勇[2] 孟祥连[1] 胡卸文[2] 赵文[1] 常帅鹏[1] 冯武超 FU Wei;HUANG Yong;MENG Xianglian;HU Xiewen;ZHAO Wen;CHANG Shuaipeng;FENGWuchao(China Railway First Survey and Design Institute Group Co.Ltd,Xi’an,Shaanxi 710043,China;Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043 [2]西南交通大学,成都610031

出　　处：《铁道工程学报》2024年第12期88-93,共6页Journal of Railway Engineering Society

基　　金：陕西省重点研发计划项目(2023-YBSF-238);铁一院重点研发项目(2022KY53ZD-10)。

摘　　要：研究目的:煤系地层中CH_(4)有害气体一直是威胁隧道施工安全主要危险源之一,对于施工期间高浓度CH_(4)有害气体预测和处置不当,极易发生爆炸、火灾等重大安全事故。因此如何实现远距离准确探测、快速评价并实时报警成为保障隧道施工安全的重要措施。本文针对隧道CH_(4)有害气体的长距离非接触式精细化探测需求,研制基于近红外吸收光谱方法的CH_(4)遥测系统,实现隧道CH_(4)有害气体远距离快速测量,能够精准快速定位有害气体源头并实时预警。后续可对CH_(4)害气体浓度变化特征、扩散趋势进行分析,实现其浓度反演与泄漏预报,为主动防灾与智能决策提供科学依据。研究结论:(1)采用分布式反馈(DFB)二极管激光器作为光源,覆盖选定的6046 cm^(-1)吸收线,以减少CO_(2)和H_(2)O的干扰;(2)由FPGA构成波形发生器和数字正交锁相放大器,产生驱动信号,提取WMS-1f和2f信号;(3)采用“2f/1f”方法消除光强波动等环境影响,提高信噪比;(4)该CH_(4)遥测技术具有响应快、抗环境干扰强的特点,能满足隧道CH_(4)有害气体的长距离探测需求。Research purposes:Harmful CH_(4)gas has always been one of the main hazard sources threatening the safety of tunnel construction.For the improper prediction and disposal of high concentrations of hazardous CH_(4)gas during construction,it is easy to cause explosion,fire,and other major safety accidents.Therefore,how to realize remote accurate measurement,rapid evaluation,and real-time alarm has become an important method to ensure the safety of tunnel construction.In this paper,a CH_(4)telemetry system based on near-infrared absorption spectroscopy is developed to meet the requirement of long-distance and fine measurement of harmful gas in tunnel CH_(4),to realize rapid longdistance measurement of harmful gas in tunnel CH_(4),accurately and quickly locate the source of harmful gas and give real-time warning.Subsequently,the variation characteristics and diffusion trend of CH_(4)harmful gas concentration can be analyzed,and its concentration inversion and leakage prediction can be realized,which provides a scientific basis for active disaster prevention and intelligent decision-making.Research conclusions:(1)The distributed feedback diode laser is applied as the light source to cover the selected absorption line of 6046 cm^(-1) to reduce the interference of CO_(2) and H_(2)O.(2)The waveform generator and the digital quadrature lock-in amplifier are constructed by the FPGA to produce driving signals and extract WMS-1f and 2f signals.(3)The“2f/1f”method is adopted to eliminate environmental influences such as light intensity fluctuations and improve the signal-to-noise ratio.(4)This methane telemetry has the characteristics of fast response and strong resistance to environmental interference,which can meet the requirement of long-distance measurement of harmful gas CH_(4)in the tunnel.

关 键 词：隧道有害气体 CH4浓度 长距离探测 近红外吸收光谱 2f/1f测量方法 

分 类 号：U25[交通运输工程—道路与铁道工程]