分布式光纤甲烷监测系统的设计与实现

发布时间：2019-06-22 10:31

【摘要】：目前,国内煤矿和家庭天然气爆炸的情况时有发生,给国家和个人的财产造成了巨大的损失,因此甲烷气体浓度的检测一直以来都是备受关注的焦点问题。煤矿、城市地下管道和排污管道等检测环境,使其检测具有很大的复杂性和艰难性。为了能够在复杂的环境下实现甲烷气体浓度的高精度和高稳定性检测,设计出基于光谱吸收原理的光纤甲烷检测系统,并提出用锯齿波调制半波扫描的方法进行检测,实现在复杂条件下进行高精度和高稳定性测量的特性。系统采用分布式测量,用一个光源同时对多点进行实时在线的监测,大大降低了成本;分布式的实现可以构成分布式网络,能够对监测区域进行更加全面的测量。首先,以检测的基本原理和气体的吸收线型为基础,确定了系统的基本检测方式,即锯齿波调制半波扫描的检测方法。根据甲烷气体的吸收谱图,确定了气体的吸收谱线位置。其次,通过系统的检测方法,结合实际情况,给出了系统的器件选型原则,确定了该系统各个模块的选型规则;结合系统的选型规则,设计出系统的硬件电路部分,并根据硬件电路需求的功能设计出系统的软件功能模块。并根据分布式的实现原理,设计并实现了系统的分布式。再次,通过研究检测过程中气体浓度的分布规律,提出了利用卡尔曼滤波算法来提高检测的稳定性和精度,并验证了其可行性。最后,给出了整个系统的性能指标。该系统采用锯齿波调制的半波扫描方式,可以准确测得甲烷气体浓度;测量范围为0%-9.99%,精度为10ppm,稳定性为0.01%。高低温测试表明该系统经在复杂环境下受温度影响小,精度高,稳定性好,抗干扰能力强。
[Abstract]:At present, the explosion of natural gas in domestic coal mines and households has occurred from time to time, which has caused great losses to the property of countries and individuals, so the detection of methane gas concentration has always been the focus of attention. The detection environment of coal mine, urban underground pipeline and sewerage pipeline makes it very complex and difficult. In order to realize the high precision and stability detection of methane gas concentration in complex environment, an optical fiber methane detection system based on spectral absorption principle is designed, and the method of sawtooth wave modulation half wave scanning is proposed to realize the characteristics of high precision and high stability measurement under complex conditions. The system adopts distributed measurement and real-time online monitoring of multiple points with one light source at the same time, which greatly reduces the cost, and the distributed implementation can form a distributed network and can measure the monitoring area more comprehensively. Firstly, based on the basic principle of detection and the absorption line of gas, the basic detection method of the system, that is, the detection method of sawtooth wave modulation half-wave scanning, is determined. According to the absorption spectrum of methane gas, the position of absorption spectrum line of gas is determined. Secondly, through the detection method of the system, combined with the actual situation, the principle of device selection of the system is given, and the selection rules of each module of the system are determined. Combined with the selection rules of the system, the hardware circuit part of the system is designed, and the software function module of the system is designed according to the function of the hardware circuit. According to the principle of distributed implementation, the distributed system is designed and implemented. Thirdly, by studying the distribution law of gas concentration in the detection process, the Kalman filter algorithm is proposed to improve the stability and accuracy of the detection, and its feasibility is verified. Finally, the performance index of the whole system is given. The methane gas concentration can be accurately measured by sawtooth wave modulation half wave scanning, the measurement range is 0% 鈮，

本文编号：2504496