采用激光吸收光谱测量高温条件下CO体积分数及其影响因素的研究

In Situ Measurements of CO in Combustion Gases Based on TDLAS and Analysis on Relevant Influencing Factors

采用中心波长位于2.3μm的半导体激光器,结合扫描波长直接吸收法,对高温条件不同工况下的CO气体谱线吸收特性进行了测量,分别研究了压力和温度对谱线线宽和吸收线强的影响.结果表明:随着压力的提高,谱线宽度逐渐增加,选择的激光器需要有足够宽度的扫描范围,R(30)谱线高压下独立性好,不与周围干扰谱线发生叠加,是理想的CO测量吸收谱线;通过消除背景信号的方法可减少颗粒对谱线吸收测量精度的影响;所选波段的谱线在高温时(>1 000K)有足够的线强,可以得到直接吸收(DA)信号,避免了采用调制技术带来的复杂性,为研究各种因素的影响提供了便利.

Spectral parameters of CO absorption line were measured under different combustion conditions using a 2.3 μm diode laser by scanned-wavelength direct absorption （DA） strategy based on tunable diode laser absorption spectroscopy （TDLAS）, so as to study the influence of pressure and temperature on the width and intensity of absorption line. Results show that the line width increases gradually with the rise of pressure, which requires the laser to have a wide scanning range spectral line R（30） is highly independent at high pressures, without superimposition with other interference lines, therefore is suitable for measurement of CO absorption line the influence of particles on measurement precision can be reduced by back- ground elimination method the intensity of lines in selected band is strong enough at high temperatures （〉1 000 K）, so that direct absorption signals can be obtained, and the complexity of modulation technique can be avoided, which therefore may serve as a reference for study of.relevant influencing factors.