基于三光路光声光谱法检测烟气氮氧化物  

Study on Detecting Gas Nitrogen Oxides Based on Research of Three-time Light Path on Photoacoustic Spectroscopy

作　　者：龚雨含[1] 粘山坡[1] 王崇皓 龚瑞昆[1] 

机构地区：[1]河北联合大学,河北唐山063009

出　　处：《仪表技术与传感器》2014年第10期85-86,89,共3页Instrument Technique and Sensor

摘　　要：介绍了光声光谱信号产生机理,推导了时间三光路氮氧化物光声光谱实时在线测量模型,分析了烟气中水蒸汽对其测量的干扰机制,为氮氧化物测量仪的设计提供理论基础。设计了烟道气中氮氧化物光声光谱检测试验系统,定量分析了激发光源波动产生的光声信号响应,综合分析气体吸收率和抗交叉敏感因素,确定了NO和NO2干涉滤光片中心波长为5 350 nm和6 300 nm.测定了NO、NO2气体循检时间小于38 s,检测灵敏限达到l.45 ppm和4.55 ppm,验证了该方法可行性及快速性。This paper introduced the mechanism of photoacoustic signal. Real-time on-line measurement model of three-time light path of nitrogen oxides of photoacoustic spectroscopy was derived, the jamming mechanism of vapor in the flue gas on the measurement was analyzed, and a theoretical basis for the design of nitrogen oxides measuring instrument was provided. The experi- ment system to detect photoacoustic spectra of nitrogen oxides in flue gas was designed and quantitative analysis of the photoacous- tic signal in response to the excitation light source fluctuation was made. Comprehensive analysis of gas absorption rate and resist- ance to cross sensitivity factors show that the interference filter center wavelength of NO and NO2 should be determined in 5 350 nm and 6 300nm. It is measured that the detection time of NO and NO2 gas is less than 38S,sensitive detection limits of them are 1.45 ppm and 4.55 ppm with good linearity, and the feasibility and rapidity of the method are verified.

关 键 词：光声光谱法 氮氧化物 时间三光路 交叉敏感 在线测量 重叠光谱 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]