环境污染气体荧光与吸收谱检测技术及系统实现

Sulfur dioxide and methane are the main environmental pollution gas. They destruct the manufacturing and ecological environment and also harm human health severely. Safety accidents induced by methane threaten the normal operation of coal and petrochemical enterprises and the safety of the workers. Absorption and fluorescence spectrum characteristic of sulfur dioxide and methane gas are researched in this subject. The quantitative relationship and the corresponding mathmatical model between the absorption line intensity in ultraviolet and visible band, fluorescence intensity or life and gas content are established. On this basis the gas concentration full optical fiber detection system is constructed. The fluorescence spectrum and absorption spectrum detection technology are combined in this system, which can realize the high precision and real-time monitoring of the environmental pollution and hazardous gas concentration. The instrument's range of applicability can be expanded by the proper transformation of the instrument hardware structure. According to the optical transmission and sensing characteristics of photonic crystal fiber, photon crystal optical fiber probe with high sensitivity is designed and developed to achieve the detections of more other gas. The instrument and the system can not only proceed continuous monitoring and warning on hazardous gas in the regions ranging over coal, petrochemical and metallurgical industries, but also provide the pollution information and accurate data for the environmental protection departments and factories. It will also promote the development of domestic environmental monitoring instruments.

二氧化硫及甲烷等是主要的环境污染气体，对生产及生态环境破坏较大并严重危害着人类健康。由甲烷引发的安全事故，对煤炭、石化等企业的正常运营及职工生命安全构成了严重威胁。课题研究二氧化硫及甲烷等气体的吸收及荧光光谱特性，分别建立紫外及可见波段吸收线光强、荧光光强或寿命与气体含量间的定量关系及相应数学模型。在此基础上，构建气体浓度全光纤检测系统。系统将荧光谱与吸收谱检测技术相结合，实现对环境污染及危险气体浓度的高精度、实时监测。适当变换仪器硬件结构，可拓展仪器的适用性及使用范围。利用光子晶体光纤传光及传感特性，设计并研制高灵敏度光子晶体光纤探头，实现多种气体检测。研究的仪器及系统不仅可以对煤炭、石化、冶炼等行业区域的危险气体进行连续监测和预警，还可为环保部门和工厂提供污染状况资料和精确的数据，将对我国环境监测仪器的发展起到推动作用。

本项目针对环境污染气体的成分识别和含量测量展开研究工作，研究重点是针对现有仪器检测种类单一，定量检测精度不足，微弱信号测量等问题。课题以甲烷和二氧化硫为典型对象，对被测气体的荧光光谱和吸收光谱特性、检测仪器的设计以及光谱信号分析进行了深入研究，主要工作包括：研究了甲烷和二氧化硫等常见污染气体的光谱特性，确定吸收光谱和荧光光谱的影响因素，在研究光谱与气体浓度关系的基础上，建立数学模型；研究检测系统各模块，采用组合光源、差分/谐波技术搭建了光纤检测系统；通过对空芯光子带隙光纤的特性研究，构建全光纤检测系统，提高系统的检测灵敏度；通过对小波算法和经验模态分解算法的去噪研究，对比两种算法分别对吸收光谱和荧光光谱的去噪结果，实现对微弱信号的提取和处理。