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摘要: 本文基于可调谐半导体 吸收谱线(TDLAS)技术的直接吸收测量,选用中心工作波长为1 580 nm的DFB 器,在室温及大气常压条件下检测了模拟烟气中的CO2浓度;采用去峰拟合法和纯N2线拟合法获得基线后反算出了CO2的浓度,并将反算结果进行了对比。结果表明:采用纯N2线拟合法反算出的浓度的最大相对误差为2.64%,均方值为1.69%;采用去拟合法反算出的浓度的最大相对误差为9.81%,均方值为7.81%。以纯N2吸收谱线作基线的纯N2线拟合方法反算出的浓度的准确度较高,可以为CO2浓度测量的基线选择提供参考。
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关键词:
- 可调谐半导体 吸收谱线技术 /
- 直接吸收 /
- CO2测量 /
- 光谱分析
Abstract: Based on the direct absorption measurement of absorption spectrum of tunable diode laser absorption spectroscopy (TDLAS) technology, the DFB laser of 1 580 nm center wavelength is chosen to detect the concentration of CO2 in simulated flue gas at room temperature and atmospheric pressure. The concentration of CO2 is computed by removing absorption peak fitting method and pure N2 line fitting method, and the two computed results are compared. The results show that the maximum relative error of concentration is 2.64% for the pure N2 line fitting method, and the mean square value is 1.69%; the maximum relative error of concentration got from the removing absorption peak fitting method is 9.81%, and the mean-square value is 7.81%. Using the method of pure N2 line fitting method, the accuracy of concentration is greatly improved, so the method can provide baseline selection reference for CO2 measurement. -
图 1 CO2、H2O、NO在1 580 nm附近的吸收谱线图[12]
Figure 1. Absorption lines of CO2, H2O, NO nearby 1 580 nm
表 1 去峰拟合法处理得到的结果
Table 1. Results obtained by the removingabsorption peak fitting method
Serial
numberTrue
concen-
tration/%Fitted
concen-
tration/%Absolute
error/%Relative
error/%1 10 9.5 -0.48 -4.88 2 12 10.8 -1.17 -9.81 3 14 12.7 -1.27 -9.12 4 16 14.9 -1.04 -6.51 5 18 16.7 -1.22 -6.81 6 20 18.3 -1.71 -8.56 表 2 纯N2线拟合法处理得到的结果
Table 2. Results obtained by the pure N2 line fitting method
Serial
numberTrue
concen-
tration/%Fitted
concen-
tration/%Absolute
error/%Relative
error/%1 10 10.1 0.05 0.55 2 12 12.2 0.27 2.32 3 14 14.3 0.37 2.64 4 16 16.1 0.12 0.78 5 18 17.9 -0.03 -0.17 6 20 19.6 -0.38 -1.92 -
[1] 张建宇, 潘荔, 杨帆, 等.中国燃煤电厂大气污染物控制现状分析[J].环境工程技术学报, 2011, 1(3):185-196. http://www.cnki.com.cn/Article/CJFDTOTAL-ZHBY200904020.htmZHANG J Y, PAN L, YANG F, et al.. Study on current status of air pollution control for coal-fired power plants in China[J]. Journal of Environmental Engineering Technology, 2011, 1(3):185-196. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-ZHBY200904020.htm [2] 李亚萍, 张广军, 李庆波.空间双光路红外CO2气体传感器及其测量模型[J].光学精密工程, 2009, 17(1):14-19LI Y P, ZHANG G J, LI Q B. Infrared CO2 gas sensor based on space double beams and its measurement model[J]. Optics and Precision Engineering, 2009, 17(1):14-19. (in Chinese) [3] 潘卫东, 张佳薇, 戴景民, 等.可调谐半导体 吸收光谱技术检测痕量乙烯气体的系统研制[J].光谱学与光谱分析, 2012, 32(10):2875-2878. doi: 10.3964/j.issn.1000-0593(2012)10-2875-04PAN W D, ZHANG J W, DAI J M, et al.. Tunable diode laser absorption spectroscopy system for trace ethylene detection[J]. Spectroscopy and Spectral Analysis, 2012, 32(10):2875-2878. (in Chinese) doi: 10.3964/j.issn.1000-0593(2012)10-2875-04 [4] 何莹, 张玉钧.基于 吸收光谱开放式大气CO2的在线监测[J].光谱学与光谱分析, 2009, 29(1):10-13. doi: 10.3964/j.issn.1000-0593(2009)01-0010-04HE Y, ZHANG Y J. Open-path online monitoring of ambient atmospheric CO2 based on laser absorption spectrum[J]. Spectroscopy and Spectral Analysis, 2009, 29(01):10-13. (in Chinese) doi: 10.3964/j.issn.1000-0593(2009)01-0010-04 [5] 姜波.提高CEMS测量可靠性的方法[J].资源节约与环保, 2014(9):73-74. http://www.cnki.com.cn/Article/CJFDTOTAL-ZYJH201409078.htmJIANG B. Methods to improve the reliability of CEMS measurement[J]. Resources Economization & Environmental Protection, 2014(9):73-74. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-ZYJH201409078.htm [6] 罗淑芹. 基于TDLAS的CO2气体检测分析系统[D]. 哈尔滨: 哈尔滨工业大学, 2013.LUO S H Q. Detection and analysis system for CO2 gas based on TDLAS[D]. Harbin:Harbin Institute of Technology, 2013. (in Chinese) [7] 涂兴华, 刘文清, 张玉钧. CO和CO2的1.58 μm波段可调谐二极管 吸收光谱的二次谐波检测研究[J].光谱学与光谱分析, 2006, 26(7):1190-1194.TU X H, LIU W Q, ZHANG Y J. Second-harmonic detection with tunable diode laser absorption spectroscopy of CO and CO2 at 1.58 μm[J]. Spectroscopy and Spectral Analysis, 2006, 26(7):1190-1194. (in Chinese) [8] 李宁. 基于可调谐 吸收光谱技术的气体在线检测及二维分布重建研究[D]. 杭州: 浙江大学, 2008.LI N. Research on gas detection and 2D distribution reconstruction by tunable diode laser absorption spectroscopy technique[D]. Hangzhou:Zhejiang University, 2008. (in Chinese) [9] 张志荣, 夏滑, 董凤忠.可调谐半导体 吸收光谱方法的多组分气体浓度同时在线监测技术[J].光学精密工程, 2013, 21(11):2771-2777. http://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201311006.htmZHANG ZH R, XIA H, DONG F ZH. Simultaneous and on-line detection of multiple gas concentration with tunable diode laser absorption spectroscopy[J]. Optics and Precision Engineering, 2013, 21(11):2771-2777. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201311006.htm [10] 曾怡帅, 杨友良, 马翠红.有尘环境多组分气体成分检测系统的设计[J].发光学报, 2016, 37(7):859-865. http://www.cnki.com.cn/Article/CJFDTOTAL-FGXB201607027.htmZENG Y SH, YANG Y L, MA C H. Design of the detection system of multi component gas composition in dust environment[J]. Chinese Journal of Luminescence, 2016, 37(7):859-865. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-FGXB201607027.htm [11] 陈霄, 隋青美, 苗飞, 等.应用单一超窄线宽 器的多气体检测系统设计[J].光学精密工程, 2011, 19(7):1495-1502. http://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201107013.htmCHEN X, SUI Q M, MIAO F, et al.. Design of detecting system for multi-component gases based on single ultra-narrow-linewidth laser[J]. Optics and Precision Engineering, 2011, 19(7):1495-1502. (in Chinese) http://www.cnki.com.cn/Article/CJFDTOTAL-GXJM201107013.htm [12] HITRAN. HITRAN Database[Z/OL].[2017-02-21].http://www.hitran.org. [13] 姚华. 采用可调谐 吸收光谱技术遥测甲烷气体浓度的研究[D]. 杭州: 浙江大学, 2011.YAO H. Research on remote sensing of methane based on tunable diode laser absorption spectroscopy technique[D]. Hangzhou:Zhejiang University, 2011. (in Chinese) [14] 窦贺鑫. 基于TDLAS的气体在线检测系统研究[D]. 天津: 天津大学, 2007.DOU H X. Detection and analysis system for CO2 gas based on TDLAS[D]. Tianjin:Tianjin University, 2007. (in Chinese) [15] 何莹, 张玉钧, 阚瑞峰, 等.基于 吸收光谱乙炔在线监测技术的研究[J].光谱学与光谱分析, 2008(10):2228-2231. doi: 10.3964/j.issn.1000-0593(2008)10-2228-04HE Y, ZHANG Y J, KAN R F, et al.. The development of acetylene on-line monitoring technology based on laser absorption spectrum[J]. Spectroscopy and Spectral Analysis, 2008(10):2228-2231. (in Chinese) doi: 10.3964/j.issn.1000-0593(2008)10-2228-04