INVESTIGATION OF CONTINUOUS MEASUREMENT OF SO2, NO2 CONCENTRATION IN FLUE GASES BY DOAS WITH KALMAN FILTER
IntroductionIn the past decades, Differential Optical Absorption Spectroscopy(DOAS) has been widely used for monitoring of trace gases1-5 in the stratosphere or troposphere. It was platt et al.1-2 who first started to utilize the differential absorption for tropospheric gas composition measurement simultaneously without disturbing the chemical behaviors of substances to be investigated. The most straightforward atmospheric molecules to detect with DOAS are SO2, NO2 and O35-7 in the u.v./visible In the tropospheric application, the light from a broad band xenon lamp is transmitted through the atmosphere for distances up to several kilometers. After the light is received, the measurement spectrum is matched to the spectral absorption of known molecules applying the least-squares fitting to derive gas concentrations However, it is very difficult to be used for the monitoring of low concentration flue gas or for the flue gas mixed with dust particles of high concentration at so short light path length with traditional DOAS technique, hi the present article, an improved DOAS algorithm based on Kalman filter was investigated and developed to greatly improve the accuracy and sensitivity at short light path length. Different from the traditional DOAS algorithm, the Kalman filter applied linear recursion at all wavelengths in a certain wavelength region The improved DOAS technique can be used to lower the detection limit. Also, if it is combined with traditional DOAS by setting an appropriate threshold for the differential optical density, then it can be used to enlarge the dynamic measurement range.
Gnanghua Tang Chuanlong Xu Litang Shao Bin Zhou Daoye Yang Qi Pan Shimin Wang
School of Energy and Environment, South East University,Nanjing, 210096, China
国际会议
The 7th China-Korea Workshop on Clean Energy Technology(第七届中韩清洁能源技术研讨会)
太原
英文
151-152
2008-06-25（万方平台首次上网日期，不代表论文的发表时间）