【作者】 陈强强；

【导师】 余学义；

【作者基本信息】 西安科技大学 ， 采矿工程， 2010， 硕士

【摘要】 煤炭是我国国民经济发展的重要能源，而目前瓦斯事故已经成为制约我国煤炭安全生产的主要因素，实现瓦斯气体的简便、准确、实时监测，对我国煤矿安全生产和经济社会建设都具有极其重要的意义。光谱吸收法气体检测技术基于分子的选择吸收性，即在被测气体的光吸收过程中，由于分子结构的能量分布的差异所导致不同的气体物质有不同的吸收峰带。与目前普遍采用的热催化元件及气敏检测法等相比，该技术具有更高的灵敏度、分辨率和抗干扰性，而且可实时监测，成为未来气体检测技术的发展方向。本文以煤矿瓦斯的主要成分甲烷为目标气体，研究设计了基于可调谐半导体激光吸收光谱法(TDLAS)和谐波检测技术相结合的瓦斯浓度监测系统。通过对气体近红外选择性吸收的理论分析，给出了气体吸收测量的理论依据，选取了系统检测采用的CH4分子吸收线，并讨论确定了基于谐波检测技术的瓦斯浓度计算方案；根据检测性能要求，甄选了系统光学检测所用的可调谐半导体激光二极管、LD驱动板卡和光电探测器型号；在信号处理部分，研究开发了以锁相放大技术为核心的微弱信号检测电路模块，利用调制信号产生的二次谐波与直流分量的比值R20作为浓度检测信号；设计了以MSP430为中心的系统控制计算模块，以及液晶显示电路；在数据传输部分，研究确定了系统的无线数据传输结构，并选用ROC101007/1蓝牙模块设计了无线传输接口电路。研发过程中始终以系统的高性能监测和便捷操作为出发点，便于实现集成化。通过相同或相似条件下实验论证及理论计算表明，系统浓度计算方案可行，而且灵敏度和分辨率均可满足煤矿实际监测要求。更多还原

【Abstract】 Mine coal is important resource of our nationa l economy development, but recently gasaccidents have been the restrictive factor to our coal industria l safety production. So it is veryimportant to coal mine safety production and economic society construction while realizingconvenient, accurate and real-time monitoring to mine gas.Spectrum absorption sensing technology bases on the selective absorbability of gasmolecule, namely different gases have their own characteristic absorption peaks due to energydistribution in molecular structure, which decides the selectivity and identification ofspectrum absorption sensing technology. Comparing with widely adopted catalytic sensor andgas-sensitive detection, it has the better sensitivity, resolution and anti-interferenceperforma nce, and it also can realize real time monitoring. So it has become the developmenttrend of gas measure technology.While using the ma in component of mine gas methane as the target sample , this paperresearches and designs the gas concentration monitoring system based on TDLAS andharmonic detection. After analyzing the theory of near-infrared selective absorption of gas, itdescribes the academic base of the measurement of the gas by absorption theory and confirmsthe absorption spectra of methane. Different mathematica l models of gas concentrationharmonic measurement are built up. In the optica l part, according to detection requirements itselects the LD, LD drive and photodetector. In the signa l modulation part, the paper designsthe weak signa l measure circuits with the core of lock-in technology, and using the lightsource modulation harmonic modulation to realize the measure. In the data processing part, itdesigns the controlling and calculating module based on MSP430, as well as LCD displa ycircuit. In the data transmission part, it researches and confirms the wireless data transmissionstructure, and designs the wireless interface circuit by Bluetooth module ROC101007/1. The system is built up with the basic purpose of high performa nce and convenient operation, and itcan be integrated. After experimental demonstration in the same or similar conditions andtheoretica l calculation, the confirmed concentration mathematica l model is feasible, and bothsensitivity and resolution of system can meet the requirements of practica l monitoring in coalmine.更多还原