基于数字信号处理技术的甲烷实时监测系统的设计

发布时间：2018-08-15 16:51

【摘要】：社会进步给我们生活带来便捷的同时,也对环境造成了污染,大气污染是各种污染中重要的一个方面,直接危害人类的生活质量及健康。 CH4与CO、CO2和含氯氟烃等是造成大气温室效应的主要的气体,CH4对温室效应的作用是同浓度CO2的22倍,所以对CH4的检测和治理变得非常重要,目前对大气污染物的检测广泛采用可调谐二极管吸收光谱技术(TDLAS),对采集到的信号采用数字信号处理的办法,具有准确度高,稳定性好等优点,本文针对实时监测系统的设计主要进行了以下几个方面的研究和讨论： (1)分析比较气体检测的常用方法,对TDLAS技术的特点和优势作了说明,介绍了数字信号处理技术的发展和应用。 (2)描述了实时监测系统的原理,主要包括TDLAS技术中所应用到的光谱学技术、甲烷吸收线的选择及波长调制技术的原理。 (3)提出了实时监测系统硬件电路方面的设计及实验器件的选择,包括信号调制电路的设计、光源及其驱动器的选择、倍频电路及锁相放大电路的设计,最后简单介绍了信号处理部分。 (4)对实时监测系统的软件的设计,包括系统总体软件的设计、数据采集的软件设计、数据处理软件的设计及仿真。
[Abstract]:Social progress not only brings convenience to our life, but also pollutes the environment. Air pollution is an important aspect of all kinds of pollution. CH4, CO _ 2 and chlorofluorocarbons are the main gases causing atmospheric Greenhouse Effect. CH4 has 22 times more effect on Greenhouse Effect than on the same concentration of CO2. So the detection and treatment of CH4 becomes very important. At present, tunable diode absorption spectroscopy (TDLAS),) is widely used to detect atmospheric pollutants. (TDLAS), adopts the method of digital signal processing for the collected signals, which has high accuracy. In this paper, the design of real-time monitoring system is studied and discussed in the following aspects: (1) the common methods of gas detection are analyzed and compared, and the characteristics and advantages of TDLAS technology are explained. The development and application of digital signal processing technology are introduced. (2) the principle of real-time monitoring system is described, including the spectroscopic technology used in TDLAS technology. The selection of methane absorption line and the principle of wavelength modulation technology. (3) the design of hardware circuit of real-time monitoring system and the selection of experimental devices, including the design of signal modulation circuit, the choice of light source and its driver, The design of frequency-doubling circuit and phase-locked amplifier circuit. Finally, the signal processing part is introduced briefly. (4) the software design of real-time monitoring system, including the design of system software, the software design of data acquisition, Design and simulation of data processing software.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP274;TP368.1

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