分布式激光甲烷检测系统及温度补偿技术研究

Research on distributed laser methane detection system and temperature compensation technology Research on distributed laser methane detection system and temperature compensation technology

瓦斯浓度检测精度不高、传感器后期检修工作量大,是当前煤矿瓦斯灾害防治中存在的重要问题。针对这一问题,设计了一种光纤传输的分布式激光甲烷检测系统,并研究了其配套的温度补偿方案。阐述了采用可调谐激光光谱吸收技术和光复用技术进行多通道系统设计的方法,进而分析环境温度变化与甲烷吸收光谱的影响关系,在此基础上提出了一种基于实验测试数据的多变量自适应温度补偿算法,实现了瓦斯浓度在大空间复杂温度场条件下的准确检测。测试结果表明:该系统能够实现64个测点在10 km范围内的准确检测;进行温度补偿后,在0~40.0℃温度变化范围内,甲烷体积分数测量范围为0~100.00%,测量误差小于±2.00%。该系统适用于煤矿通风巷道、采煤工作面等危险场所,具有测量精度高、信息覆盖面广、气室无源、本质安全、成本低等特点,可为煤矿瓦斯突出预警和瓦斯抽采提供准确的基础数据。

The detection accuracy of gas concentration is not high and the workload of sensor maintenance is large,which are the important problems in coal mine gas disaster prevention and control at present.To solve these problems,a distributed laser methane detection system based on fiber transmission was designed and its temperature compensation scheme was studied.The method of multichannel system design using tunable laserl absorption technology and optical multiplexing technology was described,and then the relationship between ambient temperature change and absorption spectrum of methane was analyzed.On this basis,a multi-variable adaptive temperature compensation algorithm based on experimental data was proposed,which realized the accurate detection of gas concentration in large space and complex temperature field.The test results show that the system can realize the accurate detection of 64 measuring points in the range of 10 km.After temperature compensation,the measurement range of methane volume fraction is 0 to 100.00%and the measurement error is less than±2.00%in the temperature range from 0℃to 40.0℃.The system is suitable for coal mine ventilation roadway,coal mining face and other dangerous places.It has the characteristics of high measurement accuracy,wide information coverage,passive air chamber,intrinsically safety and low cost,and can provide accurate basic data for coal mine gas outburst warning and gas extraction.