基于TDLAS技术的在线多组分气体浓度检测系统

摘要

为了提高环境气体监测精度,降低设备维护成本需求,设计了一种多组分气体同时或近同时在线检测系统.该系统基于TDLAS技术采用DFB可调谐激光测量气体浓度,能够实现760 nm O2和2 326 nm CO混合气体同时在线监测.设计发射单元、接收单元等模块,分析TDLAS可调谐激光检测、PID温度控制、锁相检测原理.结合火电厂烟道氧量浓度测试,对系统进行了验证.实验结果表明:与传统的工业气体测量装置相比,该系统能获得更高的精度、更快的响应速度以及良好的稳定性,适应恶劣环境能力强,具有较好的实用性及可行性.%In order to improve the accuracy of detecting the environmental gas in the industry and satisfy the requirement for reducing the equipment cost,a meanwhile online or nearly meanwhile on-line multi-component gas detection system was designed.Based on TDLAS technology,this system adopted the DFB tunable laser to detect the gas concentration.Moreover,it can also realize the online simultaneous detection of the mixed gas of 760 nm O2 and 2 326 nm CO.This paper designed and analyzed the modules such as transmitting unit and Receiving unit.TDLAS tunable laser detection,PID temperature control and principle of phase lock detection were analyzed.The system was verified through the test of flue oxygen concentration in the thermal power plant.According to the experimental result,comparing with the traditional industrial gas measuring device,this system has higher accuracy and faster response speed and good stability,and has the strong ability to function in the harsh environment as well as the high applicability and feasibility.