TDLAS技术中不同背景气体的混合气体浓度算法

doi:10.3964/j.issn.1000-0593(2020)10-3015-06

摘要
参考文献
相关文章 (15)

全文: PDF (3705 KB)
输出: BibTeX | EndNote (RIS)

摘要：可调谐半导体激光光谱技术（TDLAS）是目前发展十分迅速的光谱检测技术，被广泛用于检测工业环境中的易燃易爆等危险气体；这些危险气体往往是多种气体混合而成，待测气体的直接吸收光谱在不同的背景气体下会发生改变，浓度计算结果存在误差；故而提出一种新型的混合气体浓度算法。针对不同背景气体下的混合气体浓度算法进行了讨论，研究了不同背景气体下洛伦兹吸收谱产生变化的原因，并分析了峰值算法和积分算法在计算混合气浓度存在误差的原因，提出了采用Levenberg-Marquardt算法拟合出洛伦兹吸收谱，利用面积系数与标准浓度进行二次拟合来表征混合气浓度的算法。实验搭建了基于TDLAS技术的气体检测系统，采用中心波长为1 368.59 nm的激光器，气室长度为30 cm，以水汽为待测气体，干燥空气、氮气、氩气作为背景气体，利用国瑞智双压法湿度发生器GRZ5013产生40%～80%的相对湿度环境，以Mitchell-s8000露点仪的测量结果作为参考值，通过计算干燥空气为背景气体下的峰值、积分和面积系数，拟合三者与Mitchell露点仪测量的水汽浓度结果，得到三种算法二次拟合关系，再对氮气和氩气背景下的水汽浓度进行计算，对比了峰值、积分和面积系数的浓度算法的相对误差。实验表明：氮气下峰值、积分和面积系数算法的最大相对误差为-11.64%，2.65%和1.76%，最小误差为-7.79%，-0.56%和-0.54%，相对误差均方值为0.88%，0.03%和0.01%；氩气下峰值、积分和面积系数算法的最大相对误差为-109.27%，-10.13%和2.96%，最小误差为73.04%，-5.51%和1.34%，相对误差均方值为87.51%，0.61%和0.06%；面积系数表征浓度算法最优，误差最小，结果最为准确。

关键词：TDLAS；混合气；浓度算法；洛伦兹吸收谱

Abstract：Tunable Semiconductor Laser Spectroscopy (TDLAS) is a rapidly developing spectroscopic detection technology, which is widely used to detect flammable and explosive hazardous gases in the industrial environment. These hazardous gases are often mixed by various gases. The direct absorption spectrum of gas changes under different background gases which causes errors in the calculation. This paper proposes a new algorithm of mixed gases under different background gases. The algorithms of mixed gas concentration under different background gases are discussed, the reasons for Lorentz absorption spectrum changing under different background gases are studied. The reasons for errors of peak algorithm and integral algorithm in calculating mixed gas concentration are analyzed. A new method is proposed to fit the Lorentz absorption spectrum by Levenberg-Marquardt algorithm and to characterize the concentration of mixture by the quadratic fitting of area coefficient and measured concentration. In the experiment, a gas detection system based on TDLAS technology was built. The laser with a center wavelength of 1 368.59 nm was used. The length of the gas chamber was 30 cm. The water vapor was used as the gas to be tested. Dry air, nitrogen and argon were used as the background gas. The humidity generator GRZ5013 produces a relative humidity environment of 40% to 80%. Using the measurement results of the Mitchell-s8000 dew-point meter as a reference value, the quadratic fitting relationship between the three parameters (the peak, integral and area coefficients of the dry air as the background gas) and the water vapor concentration of the Mitchell dew-point meter is obtained. The relative errors of the three algorithms in the background of nitrogen and argon were compared. Experiments show that the maximum relative error of the peak, integral and area coefficient algorithms under nitrogen are -11.64%, 2.65% and 1.76%, the minimum errors are -7.79%, -0.56% and -0.54%, and the relative error mean square values are 0.88%, 0.03% and 0.01%. The maximum relative errors of the peak, integral and area coefficient algorithms under argon are -109.27%, -10.13% and 2.96%, and the minimum errors are 73.04%, -5.51% and 1.34%, and the relative error mean square values are 87.51%, 0.61% and 0.06%. The area coefficient is the best concentration algorithm in three with the smallest error and the most accurate results.

Key words：TDLAS; Gas mixture; Concentration algorithm；Lorentz spectrum

收稿日期: 2019-08-26 修订日期: 2020-01-06

中图分类号:

O433.4

基金资助: 国家重大科学仪器设备开发专项（2017YFF0105100）和国家自然科学基金项目（41705141）资助

作者简介: 陈昊，1990年生，中国科学院电工研究所博士研究生 e-mail: chenhao9@mail.iee.ac.cn

引用本文:

陈昊，鞠昱，韩立，常洋. TDLAS技术中不同背景气体的混合气体浓度算法[J]. 光谱学与光谱分析, 2020, 40(10): 3015-3020.
CHEN Hao, JU Yu, HAN Li, CHANG Yang. Algorithms for Calculating the Concentration of Gas Mixture Containting Different Background Gases in TDLAS Technology. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(10): 3015-3020.

链接本文:

https://www.gpxygpfx.com/CN/10.3964/j.issn.1000-0593(2020)10-3015-06 或 https://www.gpxygpfx.com/CN/Y2020/V40/I10/3015