A direct inverse method to measure SO2 concentration in flue gas with differential optical absorption spectroscopy

作者：Li Yafei; Cai Xiaoshu^*

来源：Proceedings of the CSEE, 2010, 30(29): 74-79.

• Differential optical absorption spectroscopy
• Emission monitoring
• Function relationships
• High concentration
• Inverse methods
• Light intensity
• Online monitoring
• SO2
• Utility boiler

For monitoring emission from utility boilers, the accuracy of differential optical absorption spectroscopy (DOAS) method is strongly affected by high concentration of dust and droplets in flue gas. Experiments were carried out in lab to simulate the real conditions in chimney. Absorption spectrums of SO2 were measured in different conditions, such as high concentration of dust and/or droplets, lower light intensity. Then, measured spectrums were analyzed with wavelet transform method. It was found that coefficients of wavelet transform in some wavelengths kept nearly constant in different conditions. Based on these experimental results, the new method of measuring concentration of SO2 was presented in this paper. Our aim is to establish the function relationships by means of using the relationships between these coefficients and the concentration of SO2, which can be used to determine the concentration of SO2 directly in DOAS method. Experiments proved this method. For the advantage of eliminating the interference of dust and droplets, reducing the measurement error, the new technique presented in this work is suitable for on-line monitoring emission from utility boilers.

• 出版日期2010