摘要
针对矿井瓦斯(甲烷)气体浓度连续、安全、原位准确的监测需求,设计一种全光路激光甲烷传感探头。甲烷探头的体积仅为φ4 cm×8 cm(圆柱体),外部为不锈钢外壳。为确保测量过程的安全性,探头内部由全光学元件组成,而无相关电学结构,利用三面反射镜构成光路系统,探头的吸收路径约为20 cm,所设计的甲烷探头具有灵敏度高、鲁棒性强以及安全性高的优点。为验证甲烷探头的性能,在实验室搭建一套基于激光探头的甲烷浓度探测系统,使用中心波长为1653.7 nm的分布式反馈半导体(distributed feedback laser,DFB)作为光源,结合波长调制光谱(wavelength modulation spectroscopy,WMS)和直接吸收光谱(direct absorption spectroscopy,DAS)的技术,实现甲烷气体的高灵敏度探测。实验结果表明,常温常压下在低浓度(0~1%)测量误差小于±5.0×10^(-4),高浓度测量误差小于真值的±5%;该传感器的探测极限(1σ标准)为68 ppm且响应时间约为10 s;在较长时间内,不同距离(1 km、2 km、5 km)测量的甲烷气体浓度基本一致。上述实验验证了设计的甲烷传感探头可对甲烷气体进行准确探测,能够应用于矿井瓦斯气体的原位监测。
A novel full optical path laser methane sensor probe has been developed for continuous,safe,and accurate in-situ monitoring of mine gas(methane)concentration.The methane probe,with a volume of only φ4 cm×8 cm(cylindrical),is housed in a stainless steel casing to ensure measurement safety.Internally,the probe consists of all optical components without any related electrical structures,utilizing a three-mirror reflection system to form the optical path.The absorption path of the probe is approximately 20 cm.The methane probe is characterized by its high sensitivity,strong robustness,and high safety.To validate its performance,a methane concentration detection system based on laser probes was constructed in the laboratory,using a distributed feedback laser(DFB)with a central wavelength of 1653.7 nm as the light source.The system combined wavelength modulation spectroscopy(WMS)and direct absorption spectroscopy(DAS)technologies to achieve high-sensitivity detection of methane gas.Experimental results demonstrate that,at room temperature and pressure,the measurement error is less than±5.0×10^(-4)for low concentrations(0~1%),and less than±5%of the true value for high concentrations,with a full-range linear fitting coefficient of 0.9998.The detection limit of the sensor(1σstandard)is 68 ppm and the response time is not exceeding 10 s.Experiments confirmed that different distances(1 km、2 km、5 km)from the probe have almost no effect on methane concentration measurements.These results confirm the probe′s capability for accurate methane detection and its suitability for in-situ mine gas monitoring.
作者
孙长伟
刘亚辉
刘旭
王艳春
Sun Changwei;Liu Yahui;Liu Xu;Wang Yanchun(School of Electronic and Electrical Engineering,Bengbu University,Bengbu 233030,Anhui,China)
出处
《应用激光》
CSCD
北大核心
2024年第6期133-143,共11页
Applied Laser
基金
安徽省高校杰出青年科研项目(2022AH020098)
安徽省高校自然科学重大项目(2022AH040256)
安徽省高校自然科学团队项目(2023AH010065)
安徽省高校自然科学研究项目(2022AH020098)
横向产学院项目(00012866)。
关键词
可调谐半导体激光吸收光谱技术
光学气体吸收池
矿井瓦斯
全光路探头
tunable semiconductor laser absorption spectroscopy
optical absorption cell
mine methane gas
full optical path prob
