差分光学吸收光谱(DOAS)技术在烟气监测中的应用研究

Measurement of Flue Gas with Differential Optical Absorption Spectroscopy

本文将差分光学吸收光谱（Ｄｉｆｆｅｒｅｎｔｉａｌ Ｏｐｔｉｃａｌ Ａｂｓｏｒｐｔｉｏｎ Ｓｐｅｃｔｒｏｓｃｏｙ；ＤＯＡＳ）技术中的浓度反演方法运用到烟气中 ＮＯ、ＮＯ２、ＮＨ３和 ＳＯ２的监测．利用它们在 ２００～２５０ ｎｍ 附近具有不同强度吸收的特性，测量烟气的吸收光谱，用ＤＯＡＳ方法反演出ＮＯ、ＮＯ２、ＮＨ３和ＳＯ２分子的浓度，这种方法消除了烟气中烟尘、水汽和其它成分的影响，使在线实时测量成为可能，在实验室内对不同气体分子浓度样气进行了测量和浓度反演，经过现场对比测量证明这种方法是正确的．

Concentration measurement of flue gas was studied with differential optical absorption spectroscopy (DOAS) in this paper. The system consisted of a broadband xenon lamp, a rotating dispersive grating and a PDA tube as a detector. The analyses of the experimental data indicated that the gases concentration of flue can be accurately measured with this method. Other gas components in flue can also be measured from their different absorption spectra. The slow variations in the spectral intensity of the light source or in the transmission of the optical system can be eliminated.