高精度便携式甲烷检测装置的设计

发布时间：2018-02-03 19:38

本文关键词： 甲烷检测光谱吸收斜波调制高精度便携式　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国作为一个发展中国家,不但人口众多,而且自然资源也相当丰富,尤其是煤炭资源的储备量巨大。随着煤矿贮藏量的不断减少,煤炭资源的开采强度也逐年加大。由于在井下作业时不能及时监测井下甲烷浓度,所以因瓦斯爆炸引起的矿难事故频有发生,这给国家和人们造成了严重的生命财产的损失。所以如何高效方便的检测矿井作业环境中的甲烷浓度成为了扼要解决的问题。针对这一问题,本文采用光谱吸收的方法,利用斜波检测以及波长调制技术,设计了一种高精度便携式甲烷检测装置。在对目前国内外的气体检测传感器及检测方法进行研究的基础上,提出了一种基于光谱吸收式光纤气体传感器。通过对甲烷分子结构和HITRAN数据库中的数据进行分析研究,确定了甲烷在近红外波段范围内的波长和吸收线强度。根据甲烷实测吸收谱线最后选定了1645.5nm作为甲烷吸收的中心波长。把朗伯-比尔定律作为计算基础,在理论和实际应用中对差分检测方法、谐波检测方法进行研究分析,最后根据其优缺点并结合便携式对整体成本和结构的要求,提出以斜波调制作为激光器的调制方法,从而实现了简化结构的作用。通过对光源模块的特定调制、信号调理模块的处理、光探测模块以及辅助功能模块的设计研究,最终完成了对系统的搭建。实验数据表明该系统检测精度优于10ppm,检测误差±0.02%,室温条件下启动时间小于10秒。本论文通过详细的研究与具体的实验,设计了一套高精度便携式甲烷检测装置,对甲烷安全预警的继续研究和改进具有很好的参考作用。
[Abstract]:As a developing country, China not only has a large population, but also has abundant natural resources, especially the huge reserves of coal resources. The mining intensity of coal resources is also increasing year by year. Because the underground methane concentration can not be monitored in time, the mine accidents caused by gas explosion occur frequently. This has caused serious loss of life and property to the country and people. Therefore, how to detect methane concentration in mine environment efficiently and conveniently has become a problem to be solved briefly. In this paper, spectral absorption method, oblique wave detection and wavelength modulation technology are used. A high precision portable methane detection device is designed, which is based on the research of gas detection sensors and detection methods at home and abroad. A kind of optical fiber gas sensor based on spectral absorption is proposed. The molecular structure of methane and the data in HITRAN database are analyzed and studied. According to the measured absorption line of methane, 1645.5 nm is chosen as the central wavelength of methane absorption. Lamber-Beer 's law is used as the meter. Basic. In the theoretical and practical applications, the differential detection method, harmonic detection method is studied and analyzed. Finally, according to its advantages and disadvantages and combined with the portable requirements for the overall cost and structure. The slant wave modulation is proposed as the modulation method of the laser, thus the function of the simplified structure is realized. Through the special modulation of the light source module, the signal conditioning module is processed. The design and research of optical detection module and auxiliary function module are completed. The experimental data show that the detection accuracy of the system is better than 10 ppmand the detection error is 卤0.02%. The startup time is less than 10 seconds at room temperature. Through detailed research and specific experiments, a set of high precision portable methane detection device is designed in this paper. The further research and improvement of methane safety early warning have good reference value.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD712

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