摘要
二氧化硫(SO_(2))和三氧化硫(SO_(3))是工业废气排放中的重要物质,对环境和人体健康危害很大,但对于他们在排放过程中的原位-在线测量一直是个挑战。采用可调谐二极管激光吸收光谱(TDLAS)技术,基于7.16μm量子级联激光器(QCL)对SO_(2)和SO_(3)进行同时检测,通过波长调制光谱技术提高测量系统的灵敏度和鲁棒性。在高温低压条件下采用单光程-小体积的气体吸收池利用TDLAS同时测量SO_(2)和SO_(3)的吸收谱线,测量的SO_(2)和SO_(3)的吸收光谱充分分离,从而确保了测量的准确性。同时,修正了温度变化对SO_(2)气体浓度测量的影响,并提出了用已知浓度的SO_(2)来定标未知浓度的SO_(3)气体。Allan方差分析表明,在34 s的积分时间内,SO_(2)的最小检测限达到了1.98×10^(−6)cm^(3)·cm^(−3),SO_(3)可探测的最低浓度为1.575×10^(−6)cm^(3)·cm^(−3)。系统的上升响应时间约为16 s,下降响应时间约为18 s。
Sulfur dioxide(SO_(2))and sulfur trioxide(SO_(3))are important substances in waste gas emission,and do great harm to both the environment and human′s health.However,in-situ and real-time measurement of SO_(2)and SO_(3)in the process of emissions has always been a challenge.Herein,tunable diode laser absorption spectroscopy(TDLAS)technology is presented to determine the mass of SO_(2)and SO_(3)simultaneously using a quantum cascade laser emitting at 7.16μm,and the sensitivity and robustness of the measurement system is improved by employing wavelength modulation spectroscopy.In this work,a simple single-pass gas cell with low-volume is used at high temperature and low pressure to ensure the spectra of SO_(2)and SO_(3)can be separated completely when measured simultaneously.Therefore,the concentration measurement of both SO_(2)and SO_(3)are reliable,since their spectral lines are not affected by spectral overlapping due to broadening.In addition,the influence of temperature on SO_(2)concentration measurement is corrected,and it is proposed to calibrate the concentration of SO_(3)with the standard concentration SO_(2)gas.According to the Allan deviation analysis,the minimum detection limit for SO_(2)can reach 1.98×10^(−6)cm^(3)·cm^(−3)with the integration time of 34 s,and that of SO_(3)is estimated as 1.575×10^(−6)cm^(3)·cm^(−3).The rise time and the fall time of the system are rapid as 16 s and 18 s,respectively.
作者
刘强强
朱宏历
郭古青
王泽育
冯仕凌
邱选兵
何秋生
李传亮
LIU Qiangqiang;ZHU Hongli;GUO Guqing;WANG Zeyu;FENG Shiling;QIU Xuanbing;HE QiuSheng;LI Chuanliang(Department of Physics,School of Applied Science,Taiyuan University of Science and Technology,Taiyuan 030024,China)
出处
《大气与环境光学学报》
CAS
CSCD
2021年第5期424-431,共8页
Journal of Atmospheric and Environmental Optics
基金
国家自然科学基金,U1810129,52076145,11904252
山西省科技成果转化引导专项项目,201904D131025
应用光学国家重点实验室开放基金,SKLAO-201902。
