摘要
苯作为挥发性有机化合物(VOCs)的重要组成部分,其大气污染状况日益引起人们的关注,中红外波段通常是分子的基频指纹吸收区,已成为痕量气体检测的重要波段,而差分吸收激光雷达是探测大气痕量气体的重要手段,故针对区域性苯浓度实时遥感问题,提出基于中红外带间级联激光器(ICL)的探测大气苯浓度路径积分型差分吸收(IPDA)激光雷达系统。首先,在分析IPDA激光雷达的探测原理的基础上,构建了IPDA激光雷达的反演算法及其误差分析模型。其次,详细分析来自HITRAN数据库的中红外3100 cm^(-1)附近苯以及主要干扰气体(如HCl,CH_(4)和H_(2)O)的吸收光谱,结合HCl和CH_(4)着重考虑了H_(2)O对探测结果的影响,选择IPDA激光雷达的测量波长和参考波长分别为3090.89和3137.74 cm^(-1)。再次,基于两个连续波ICL,设计了探测大气苯浓度IPDA激光雷达系统,并可通过控制温度和驱动电流调谐激光器的输出波长,使其波长分别稳定在强吸收谱区和弱吸收谱区,并设计了基于中红外衍射光栅的光谱分光子系统,以实现双波长接收信号的同步探测。最后,基于标准大气模型,仿真分析了不同路径长度、能见度和水汽浓度情况下激光雷达的探测性能,并搭建中红外波段检测气体池开展了测试实验,以验证该IPDA激光雷达系统的可行性。仿真及实验结果分析表明,当大气能见度为5 km,水汽浓度低于0.4%时,苯的浓度路径积(CL)在0.1~24 mg·m^(-3)·km范围内探测的相对误差优于10%,而苯的CL为5 mg·m^(-3)·km时探测相对误差优于1%;初步实验测试了中外红波段差分吸收激光雷达探测的线性相关系数R^(2)约为98.7%。
Benzene is an important component of volatile organic compounds(VOCs),and its pollution of the atmosphere has attracted increasing attention.The mid-infrared band is usually the fundamental frequency fingerprint absorption region of molecules,so it has become an important band for detecting trace gas molecules.Moreover,the differential absorption lidar is an important means of detecting atmospheric trace gases.Therefore,aiming at the problem of real-time remote sensing of regional benzene concentration,an integral path differential absorption(IPDA)lidar for detecting atmospheric benzene concentration based on inter-band cascade lasers(ICLs)is proposed.Firstly,we construct the retrieval algorithm of IPDA lidar and its error analysis model based on analyzing the detection principle of IPDA lidar.Secondly,the absorption spectra of benzene and major interfering gases(such as HCl,CH_(4) and H_(2)O)near the mid-infrared vicinity region of 3100 cm^(-1) from the HITRAN database are analyzed in detail.By considering comprehensively the influence of HCl,CH_(4) and H_(2)O on the detection results,the measurement wavelength and reference wavelength of the IPDA lidar are selected to be 3090.89 and 3137.74 cm^(-1) respectively.Thirdly,we designed an IPDA lidar for detecting atmospheric benzene concentration based on two continuous-wave ICLs.The output wavelengths of these ICLs can be tuned by controlling the temperature and driving curren,so that their wavelengths can be stabilized in the strong absorption spectrum region and the weak absorption spectrum region respectively.And then,a spectroscopic system with a mid-infrared diffraction grating as the core is designed to realize synchronous detection of dual-wavelength receiving signals.Finally,combined with the mid-latitude standard atmospheric model,the performance of lidar under the conditions of different visibilities,path lengths,and water vapor concentrations is analyzed and discussed.And then,we carry out test experiments by building a mid-infrared band detection gas ce
作者
段明轩
李仕春
刘家辉
王怡
辛文辉
华灯鑫
高飞
DUAN Ming-xuan;LI Shi-chun;LIU Jia-hui;WANG Yi;XIN Wen-hui;HUA Deng-xin;GAO Fei(School of Mechanical and Precision Instrument Engineering,Xi an University of Technology,Xi an 710048,China;Shaanxi Collaborative Innovation Center for Modern Equipment Green Manufacturing,Xi an 710048,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2023年第11期3351-3359,共9页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(62175199,61875162)
陕西省自然科学基金项目(2020JM-445)
陕西省教育厅自然科学基金项目(20JY048)资助。
关键词
中红外光谱
激光雷达
差分吸收光谱
苯浓度
Mid-infrared spectroscopy
Lidar
Differential absorption spectrum
Benzene concentration
