CO气体泛频吸收的仿真设计
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摘要
一氧化碳气体是一种无色、无味、不易被人察觉,且对人体健康具有致命危害的大气污染气体,主要来自于碳基燃料的不完全燃烧。对其进行高灵敏度的在线检测是备受关注的科学问题。解决这一问题的关键是确定CO气体检测的灵敏波长、可调谐激发光源和高灵敏度的检测方法。
本文首先采用微扰理论对CO分子振动薛定谔方程进行了理论求解,得到了莫尔斯势下的振动波函数及对应的能级能量；由此计算了CO分子基频振动吸收与第一、第二泛频振动吸收的相对强度比,并依据CO分子的热分布原理,确定了各振动吸收带中的灵敏转动支的吸收波长和对应的谱线线型函数,为CO气体的泛频吸收检测提供了理论依据。依据Hitran数据库给出的CO和CO2气体的泛频振动吸收光谱数据,在CO和CO：兼顾测量情况下,CO气体吸收检测中心波长确定为第二泛频振动吸收带的P5支跃迁(1579.74nm)。
利用Matlab中的Simulink动态仿真工具,建立了基于可调谐二极管激光吸收光谱气体检测系统的仿真模型。该仿真模型包括：波长可调谐二极管激光光源模块、样品气体气室模块和二次谐波数据检测模块,三模块有机的结合就构成了本研究的仿真系统。利用该仿真系统,可以系统的模拟可调谐二极管激光器的波长调谐、待测样品气体吸收、二次谐波数据的获得和整体二次谐波最小二乘法数据处理过程,最后得到二次谐波的反演CO气体浓度。仿真结果与预置值完全相等,从理论上验证了整体二次谐波最小二乘法数据处理算法应用于痕量气体检测的可行性。
为了进一步验证整体二次谐波最小二乘法数据处理算法的正确性,采用激光气体分析仪(纳斯克仪表公司,SP-Ⅱ型),对六种已知CO浓度的样品气体进行了二次谐波实验检测,并对所得二次谐波数据进行了整体二次谐波最小二乘法数据处理,得到了反演浓度与实际浓度符合的很好的实验结果,证实了整体二次谐波最小二乘法数据处理方法的正确性。
The CO gas is greatly harmful to human health with the characteristics of colorlessness, tastelessness and difficulty to be discerned, it mainly comes from the incomplete combustion of carbon-based fuels. The CO online sensitivity detection is a major concern scientific topic. The key to solve this problem includes determing sensitive wavelength for the gas detection, tunable laser source and high sensitivity detection method.
The Schrodinger equation of the CO molecule in vibration state is firstly solved using perturbation theory, the vibration wave function and the corresponding energy level in Morse potential are obtained. It is calculated that the absorption intensity ratio between fundamental frequency and the firs、second over-frequency and the sensitive absorption wavelength position of respective bands. In addition, according to the thermal distribution principle of CO, the sensitive absorption wavelength of rotation branch and their corresponding spectrum line-shape function of each vibration absorption band is identified, which provides a theoretical basis for the Over-frequency absorption detection. According to the Hitran database of the Over-frequency vibration absorption spectra of CO and CO2 gas, the P5 branch transition(1579.74 nm) of the second Over-frequency vibration absorption is identified as the detection central wavelength in the consideration of CO and CO2 synchronous measurement.
The simulation models are built up using the dynamic simulation tool Simulik in the Matlab, which based on the tunable diode laser absorption spectroscopy gas detection system. The model includes a wavelength tunable diode laser light source module, a sample gas chamber module and the second harmonic data detection module. The simulation system of the paper is compose of three modules. Using this simulation system,the whole detecting process is simulated which includes wavelength tuning of diode laser, the absorption of sample gas, data access of second harmonic wave and data processing based on overall second harmonic wave least squares lgorithm. The inversed concentrations of CO gas can be obtained consequently. The simulation results is consistent with preset value, which show that lgorithm of overall second harmonic least squares of data-processing is feasible to detect trace gases in theory.
In order to verify the correctness of overall second harmonic least squares data processing algorithm further, The second harmonic of the six samples CO gas are tested using laser gas analyzer(Norsk Instrument Company, II Single optical laser gas analyzer). The second harmonic data are processed using the overall second harmonic least squares lgorithm. The inversion concentration of each samples are also consistent with the actual concentration, so the correctness of overall second harmonic least squares data processing algorithm is confirmed.
本文首先采用微扰理论对CO分子振动薛定谔方程进行了理论求解,得到了莫尔斯势下的振动波函数及对应的能级能量；由此计算了CO分子基频振动吸收与第一、第二泛频振动吸收的相对强度比,并依据CO分子的热分布原理,确定了各振动吸收带中的灵敏转动支的吸收波长和对应的谱线线型函数,为CO气体的泛频吸收检测提供了理论依据。依据Hitran数据库给出的CO和CO2气体的泛频振动吸收光谱数据,在CO和CO：兼顾测量情况下,CO气体吸收检测中心波长确定为第二泛频振动吸收带的P5支跃迁(1579.74nm)。
利用Matlab中的Simulink动态仿真工具,建立了基于可调谐二极管激光吸收光谱气体检测系统的仿真模型。该仿真模型包括：波长可调谐二极管激光光源模块、样品气体气室模块和二次谐波数据检测模块,三模块有机的结合就构成了本研究的仿真系统。利用该仿真系统,可以系统的模拟可调谐二极管激光器的波长调谐、待测样品气体吸收、二次谐波数据的获得和整体二次谐波最小二乘法数据处理过程,最后得到二次谐波的反演CO气体浓度。仿真结果与预置值完全相等,从理论上验证了整体二次谐波最小二乘法数据处理算法应用于痕量气体检测的可行性。
为了进一步验证整体二次谐波最小二乘法数据处理算法的正确性,采用激光气体分析仪(纳斯克仪表公司,SP-Ⅱ型),对六种已知CO浓度的样品气体进行了二次谐波实验检测,并对所得二次谐波数据进行了整体二次谐波最小二乘法数据处理,得到了反演浓度与实际浓度符合的很好的实验结果,证实了整体二次谐波最小二乘法数据处理方法的正确性。
The CO gas is greatly harmful to human health with the characteristics of colorlessness, tastelessness and difficulty to be discerned, it mainly comes from the incomplete combustion of carbon-based fuels. The CO online sensitivity detection is a major concern scientific topic. The key to solve this problem includes determing sensitive wavelength for the gas detection, tunable laser source and high sensitivity detection method.
The Schrodinger equation of the CO molecule in vibration state is firstly solved using perturbation theory, the vibration wave function and the corresponding energy level in Morse potential are obtained. It is calculated that the absorption intensity ratio between fundamental frequency and the firs、second over-frequency and the sensitive absorption wavelength position of respective bands. In addition, according to the thermal distribution principle of CO, the sensitive absorption wavelength of rotation branch and their corresponding spectrum line-shape function of each vibration absorption band is identified, which provides a theoretical basis for the Over-frequency absorption detection. According to the Hitran database of the Over-frequency vibration absorption spectra of CO and CO2 gas, the P5 branch transition(1579.74 nm) of the second Over-frequency vibration absorption is identified as the detection central wavelength in the consideration of CO and CO2 synchronous measurement.
The simulation models are built up using the dynamic simulation tool Simulik in the Matlab, which based on the tunable diode laser absorption spectroscopy gas detection system. The model includes a wavelength tunable diode laser light source module, a sample gas chamber module and the second harmonic data detection module. The simulation system of the paper is compose of three modules. Using this simulation system,the whole detecting process is simulated which includes wavelength tuning of diode laser, the absorption of sample gas, data access of second harmonic wave and data processing based on overall second harmonic wave least squares lgorithm. The inversed concentrations of CO gas can be obtained consequently. The simulation results is consistent with preset value, which show that lgorithm of overall second harmonic least squares of data-processing is feasible to detect trace gases in theory.
In order to verify the correctness of overall second harmonic least squares data processing algorithm further, The second harmonic of the six samples CO gas are tested using laser gas analyzer(Norsk Instrument Company, II Single optical laser gas analyzer). The second harmonic data are processed using the overall second harmonic least squares lgorithm. The inversion concentration of each samples are also consistent with the actual concentration, so the correctness of overall second harmonic least squares data processing algorithm is confirmed.
引文
[1]李洁,基于光谱吸收法的光纤CO传感系统的研究,硕士论文,四川电子科技大学,2006
[2]关中辉,贺玉凯,刘中奇,煤矿井下一氧化碳气体检测发展与研究,矿山机械,2006,Vol.34，No.5,21-24
[3]W Jin,G Stewart,B Culshaw, Absorption measurement of methane gas with a broadband light source and interferometric signal processing,Optics Letters,1993,Vol.18,No.6,1364
[4]Onishchenko A M,Control of mining processes by means of infrared radiation methods,Izvestiga Vgsshikh Uchebngkh zavedenii,1991
[5]刘建国,刘文清,魏庆农,环境监测技术及其发展方向,光电子技术与信息,2001,Vol.14，No.2,7-12
[6]王栋,气体检测管及其常见品种,劳动保护,2000,No.2,37-39
[7]李红,国外新型环境监测光学技术的发展趋势,现代科学仪器,2004,No.4,42-43
[8]李洁,测量CO浓度的光纤传感器,激光与光电子学进展,2006,Vol.43，No.1,46-48
[9]B.R.Benneit,R.A.Soref,an dJ.A.DelAlamo,Carrier-induced change in refractive index of InP,GaAs,and InGaAsP,IEEE J.of Quantum Electronics,1990,Vol.26,No.1,113-122
[10]Ding Lei,Liu Wenqing,Zhang Yujun,et al.Investigation on remote measurement of automobile emission CO and CO2 by non-disperdion infrared absorption method,China Journal Of Quantum Electronics (量子电子学报),2003,Vol.20,No.4,459-464
[11]Si Fuqi,Liu Jianguo,Liu Wenqing,et al.Nor-dispersive infrared instrument based on gas filter COrrelation technology for atmodphere CO monitoring,China Journal Of Quantum Electronics(量子电子学报),2004,Vol.21,No.4,425-428
[12]Reid J,Labrie D,Second-harmonic detection with tunable diode laser comparison of experiment and theory,Appl.Phys,1981,Vol.26,No.3,203-210
[13]夏慧荣,王祖赓,分子光谱和激光光谱学导论,华东师范大学出版社,1987,11-18
[14]王国文,原子与分子光谱导论,北京大学出版社,1985
[15][加]G.赫兹堡,分子光谱与分子结构第一卷,科学出版社,1983,P.59-60
[16]周公度,结构化学基础,北京大学出版社,1984.4
[17]周世勋,量子力学教程,高等教育出版社,1979,P.173
[18]Nadezhdinskii A,Berezin A,Chernin S,et al.High sensitivity methane analyzer based on tuned near infrared diode laser,Spectrochimica Acta Part A,1999,Vol.55,No.10,2083-2089
[19]Anatoliy A,Kosterev,Alexander L,et al.Cavity ringdown spectroscopic detection of nitricoxide with a continuous_wave quantum_cascade laser,Applied optics,2001,Vol.40,5522-5529
[20]Anatoliy A,Kosterev,Frank K,et al.Thermoelectrically cooled quantum_cascade_laser_based sensor for the continuous monitoring of ambient atmospheric carbon monoxide,Applied optics,2002,Vol.41,1169-1173
[21]Rocco A,De Natale D,De Natale P,et al.A diode_laser_basespectrometer for in_situ measurements of volcanic gases,Applied Physics B,2004,Vol.78,235-240
[22]陈玖英,刘建国等调谐半导体激光吸收光谱自平衡检测方法研究,光学学报,2007,Vol.27,No.2,350-353
[23]H.Wahlquist,Modulation broadening of unsaturated Lorent-zian lines,J.Chem.Phys.,1961,Vol.35,1708-1710
[24]R.Arndt,Analytical Line Shapes for Lorentzian Signals Broadened by Modulation,J.Appl.Phys.,1965,Vol.36,2522-2524
[25]Roller C,Namjou K,James D,et al.Nitric oxide breath testing by tunable-diode laser absorption spectroscopy:application in monitoring respiratory inflammation,Applied optics,2002,Vol.41,6018-6029
[26]马维光等,气体峰值吸收系数随压强变化关系的理论分析,光谱学与光谱分析,2004,Vol.24No.2,135-137
[27]G.V.H.Wilson,Modulation Broadening of NMR and ESR Line Shapes,J.Applied Physics,1963,vol.34,3276-3285
[28]Feher M, Martin P A.,Tunable diode laser monitoring of atmospheric trace gas constituents, Spectrochimica Acta,1995,Vol.51,No.10,1579-1599
[29]Wu Sh Q,Masusaki H,Kimishima T,et al,Efficient reduction of fringe noise in trace gas detection with diode laser multipass absorption spectroscopy,Jpn.J.Appl.Phys,2000,Vol.39,4034-4040
[30]徐克尊,高等原子分子物理学,科学出版社,2002
[31]Webber M E.,Diode laser measurements of NH3 and CO2 for combustion and bioreactor applications,Stanford University,A Dissertation for the Degree of Science,2001
[32]Rothman LS,RinslandC P,Goldman A,et al.The HITRAN molecular spectroscopic database and HAWKS (HITRAN atmospheric workstation) 1996 edition,Joumal of Quantitative Spectroscopy&Radiative Transfer,1998,Vol.60,No.5,665-710
[33]Webber M E,Kim S,Sanders S T,et al.In situ combustion measurements of CO2 by use of a distributed feedback diode laser sensor near 2.0μm,Applied Optics,2001,Vol.40,No.6,821-828
[34]Nikkari J J,Di Iorio J M,Thomson M J,In situcombustion measurements of CO,H2O and temperature with a 1.58μm diode laser and two-tone frequency modulation,Applied Optics,2002,Vol.41,No.3,446-452
[35]Carey S J,McCann H,Winterbone D E,et a 1.Near infra-red absorption tomography for measurement of chemical species distribution,1st World Congress on Industrial Process Tomography,Greater Man chester,1999
[36]Mihalcea R M,Baer D S,Hanson R K,Diode lasersensor for measurements of CO,CO2,and CH, in combustion flows,Applied Optics,1997,Vol.36,No.33,8745-8752
[37]中国矿业学院数学教研室,数学手册,科学出版社,1980,P.284-285
[2]关中辉,贺玉凯,刘中奇,煤矿井下一氧化碳气体检测发展与研究,矿山机械,2006,Vol.34，No.5,21-24
[3]W Jin,G Stewart,B Culshaw, Absorption measurement of methane gas with a broadband light source and interferometric signal processing,Optics Letters,1993,Vol.18,No.6,1364
[4]Onishchenko A M,Control of mining processes by means of infrared radiation methods,Izvestiga Vgsshikh Uchebngkh zavedenii,1991
[5]刘建国,刘文清,魏庆农,环境监测技术及其发展方向,光电子技术与信息,2001,Vol.14，No.2,7-12
[6]王栋,气体检测管及其常见品种,劳动保护,2000,No.2,37-39
[7]李红,国外新型环境监测光学技术的发展趋势,现代科学仪器,2004,No.4,42-43
[8]李洁,测量CO浓度的光纤传感器,激光与光电子学进展,2006,Vol.43，No.1,46-48
[9]B.R.Benneit,R.A.Soref,an dJ.A.DelAlamo,Carrier-induced change in refractive index of InP,GaAs,and InGaAsP,IEEE J.of Quantum Electronics,1990,Vol.26,No.1,113-122
[10]Ding Lei,Liu Wenqing,Zhang Yujun,et al.Investigation on remote measurement of automobile emission CO and CO2 by non-disperdion infrared absorption method,China Journal Of Quantum Electronics (量子电子学报),2003,Vol.20,No.4,459-464
[11]Si Fuqi,Liu Jianguo,Liu Wenqing,et al.Nor-dispersive infrared instrument based on gas filter COrrelation technology for atmodphere CO monitoring,China Journal Of Quantum Electronics(量子电子学报),2004,Vol.21,No.4,425-428
[12]Reid J,Labrie D,Second-harmonic detection with tunable diode laser comparison of experiment and theory,Appl.Phys,1981,Vol.26,No.3,203-210
[13]夏慧荣,王祖赓,分子光谱和激光光谱学导论,华东师范大学出版社,1987,11-18
[14]王国文,原子与分子光谱导论,北京大学出版社,1985
[15][加]G.赫兹堡,分子光谱与分子结构第一卷,科学出版社,1983,P.59-60
[16]周公度,结构化学基础,北京大学出版社,1984.4
[17]周世勋,量子力学教程,高等教育出版社,1979,P.173
[18]Nadezhdinskii A,Berezin A,Chernin S,et al.High sensitivity methane analyzer based on tuned near infrared diode laser,Spectrochimica Acta Part A,1999,Vol.55,No.10,2083-2089
[19]Anatoliy A,Kosterev,Alexander L,et al.Cavity ringdown spectroscopic detection of nitricoxide with a continuous_wave quantum_cascade laser,Applied optics,2001,Vol.40,5522-5529
[20]Anatoliy A,Kosterev,Frank K,et al.Thermoelectrically cooled quantum_cascade_laser_based sensor for the continuous monitoring of ambient atmospheric carbon monoxide,Applied optics,2002,Vol.41,1169-1173
[21]Rocco A,De Natale D,De Natale P,et al.A diode_laser_basespectrometer for in_situ measurements of volcanic gases,Applied Physics B,2004,Vol.78,235-240
[22]陈玖英,刘建国等调谐半导体激光吸收光谱自平衡检测方法研究,光学学报,2007,Vol.27,No.2,350-353
[23]H.Wahlquist,Modulation broadening of unsaturated Lorent-zian lines,J.Chem.Phys.,1961,Vol.35,1708-1710
[24]R.Arndt,Analytical Line Shapes for Lorentzian Signals Broadened by Modulation,J.Appl.Phys.,1965,Vol.36,2522-2524
[25]Roller C,Namjou K,James D,et al.Nitric oxide breath testing by tunable-diode laser absorption spectroscopy:application in monitoring respiratory inflammation,Applied optics,2002,Vol.41,6018-6029
[26]马维光等,气体峰值吸收系数随压强变化关系的理论分析,光谱学与光谱分析,2004,Vol.24No.2,135-137
[27]G.V.H.Wilson,Modulation Broadening of NMR and ESR Line Shapes,J.Applied Physics,1963,vol.34,3276-3285
[28]Feher M, Martin P A.,Tunable diode laser monitoring of atmospheric trace gas constituents, Spectrochimica Acta,1995,Vol.51,No.10,1579-1599
[29]Wu Sh Q,Masusaki H,Kimishima T,et al,Efficient reduction of fringe noise in trace gas detection with diode laser multipass absorption spectroscopy,Jpn.J.Appl.Phys,2000,Vol.39,4034-4040
[30]徐克尊,高等原子分子物理学,科学出版社,2002
[31]Webber M E.,Diode laser measurements of NH3 and CO2 for combustion and bioreactor applications,Stanford University,A Dissertation for the Degree of Science,2001
[32]Rothman LS,RinslandC P,Goldman A,et al.The HITRAN molecular spectroscopic database and HAWKS (HITRAN atmospheric workstation) 1996 edition,Joumal of Quantitative Spectroscopy&Radiative Transfer,1998,Vol.60,No.5,665-710
[33]Webber M E,Kim S,Sanders S T,et al.In situ combustion measurements of CO2 by use of a distributed feedback diode laser sensor near 2.0μm,Applied Optics,2001,Vol.40,No.6,821-828
[34]Nikkari J J,Di Iorio J M,Thomson M J,In situcombustion measurements of CO,H2O and temperature with a 1.58μm diode laser and two-tone frequency modulation,Applied Optics,2002,Vol.41,No.3,446-452
[35]Carey S J,McCann H,Winterbone D E,et a 1.Near infra-red absorption tomography for measurement of chemical species distribution,1st World Congress on Industrial Process Tomography,Greater Man chester,1999
[36]Mihalcea R M,Baer D S,Hanson R K,Diode lasersensor for measurements of CO,CO2,and CH, in combustion flows,Applied Optics,1997,Vol.36,No.33,8745-8752
[37]中国矿业学院数学教研室,数学手册,科学出版社,1980,P.284-285