【摘要】 研究目的：煤系地层中CH₄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CH₄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CH₄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CH₄遥测系统，实现隧道CH₄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CH₄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6 046 cm^-1吸收线，以减少CO₂和H₂O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CH₄遥测技术具有响应快、抗环境干扰强的特点，能满足隧道CH₄有害气体的长距离探测需求。更多还原

【Abstract】 Research purposes:Harmful CH₄ 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 CH₄ 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 CH₄telemetry system based on near-infrared absorption spectroscopy is developed to meet the requirement of long-distance and fine measurement of harmful gas in tunnel CH₄,to realize rapid longdistance measurement of harmful gas in tunnel CH₄,accurately and quickly locate the source of harmful gas and give real-time warning. Subsequently,the variation characteristics and diffusion trend of CH₄ 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 6 046 cm^-1 to reduce the interference of CO₂ and H₂O.（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 CH₄ in the tunnel.更多还原