光学学报, 2009, 29 (3): 594, 网络出版: 2009-03-17
颗粒物Mie散射对差分吸收光谱技术的影响
Influence of Particle Mie Scattering on Differential Optical Absorption Spectroscopy
散射 差分吸收光谱术 Mie散射 粒径分布 浓度反演 scattering differential optical absorption spectroscopy(DOAS) Mie scattering particle diameter distribution concentration inversion
摘要
差分吸收光谱法(DOAS)应用于固定污染源烟气排放在线监测时,由于烟气中烟尘颗粒物含量较高,烟尘颗粒物Mie散射引起的消光对准确反演气体浓度应有一定影响。通过对1~10 μm烟尘颗粒物Mie散射对DOAS影响的数值模拟和实验研究得出,烟尘颗粒物的散射光强与颗粒粒径分布、颗粒数密度有关,随着颗粒粒径和颗粒数密度增加,气体的差分吸收度随之而增加,差分吸收度曲线的频率特性发生变化,传统DOAS算法中的应用多项式滤波已无法消除颗粒物Mie散射对气体差分吸收度的影响,气体浓度的反演结果远远偏离真实值。
Abstract
The inversion accuracy of gas concentration is influenced by the extinction derived from the Mie scattering of dust particles when the differential optical absorption spectroscopy (DOAS) is applied to on-line monitoring exhaustion of fixed pollution source. Simulation and experimental results for particles with diameter of 1~10 μm, show the intensity of particle scattering is determined by particle-size distribution and number concentration. With the increase of particle size and number concentration, the differential optical density of gases rises. Accordingly, the frequency characteristics of the differential optical density curves have also been changed. The influence of dust Mie scattering on differential optical density cannot be eliminated by polynomial filter in traditional DOAS algorithm and the inversion results of gas concentration are greatly deviated from true value.
邵理堂, 王式民, 汤光华, 许传龙. 颗粒物Mie散射对差分吸收光谱技术的影响[J]. 光学学报, 2009, 29(3): 594. Shao Litang, Wang Shimin, Tang Guanghua, Xu Chuanlong. Influence of Particle Mie Scattering on Differential Optical Absorption Spectroscopy[J]. Acta Optica Sinica, 2009, 29(3): 594.