本文關(guān)鍵詞：基于CW-QCL的長光程溫度氣體高靈敏檢測方法研究　出處：《中國科學(xué)技術(shù)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 量子級(jí)聯(lián)激光器 溫室氣體 可調(diào)諧激光吸收光譜技術(shù) 波長調(diào)制免標(biāo)定

【摘要】：復(fù)雜生態(tài)環(huán)境溫室氣體不同空間、時(shí)間尺度的濃度監(jiān)測是了解溫室氣體源與匯的基礎(chǔ)。目前適應(yīng)生態(tài)環(huán)境溫室氣體長期連續(xù)監(jiān)測的技術(shù)手段仍有待研究�？烧{(diào)諧半導(dǎo)體激光吸收光譜(Tunable Diode Laser Absorption Spectroscopy,TDLAS)是一種非侵入式光譜測量技術(shù),具有高選擇、高靈敏度、高分辨等特點(diǎn),與目前新興的中紅外量子級(jí)聯(lián)激光器(Quantum Cascade Laser,QCL)相結(jié)合,可實(shí)現(xiàn)分子"基頻"吸收光譜測量,進(jìn)一步提高檢測靈敏度,達(dá)到溫室氣體區(qū)域環(huán)境監(jiān)測需求。本文深入研究了長光程開放光路的中紅外波長調(diào)制TDLAS技術(shù),設(shè)計(jì)并集成了一套長光程CH4和N20連續(xù)監(jiān)測系統(tǒng),研究了多組分氣體交叉干擾下的光譜反演算法,實(shí)現(xiàn)多種溫室氣體高精度快速連續(xù)監(jiān)測。本文選擇了大氣中兩大主要溫室氣體CH4和N20作為目標(biāo)氣體,利用HITRAN數(shù)據(jù)庫對(duì)實(shí)際大氣環(huán)境進(jìn)行了吸收譜線的模擬與分析,選取了1275cm-1附近CH4和N2O的相鄰吸收譜線,實(shí)現(xiàn)了單激光器雙組分測量。研究了 1275cm-1波段的CW-QCL激光器的調(diào)制特性,并結(jié)合實(shí)際測量環(huán)境對(duì)調(diào)制參數(shù)進(jìn)行了優(yōu)化。在系統(tǒng)光機(jī)設(shè)計(jì)過程中,使用二向色鏡解決了紅外長光程(公里量級(jí))多光束同軸耦合的問題,設(shè)計(jì)了反射式離軸激光準(zhǔn)直結(jié)構(gòu)及基于離軸拋物面鏡的開放光路收發(fā)一體光機(jī)結(jié)構(gòu),能夠?qū)崿F(xiàn)公里量級(jí)的長光程開放光路監(jiān)測。本文深入研究了基于標(biāo)定與免標(biāo)定的多組分光譜-濃度反演算法�；跇�(biāo)定方法,首先提出了基于標(biāo)定的多元線性擬合的WMS(Wavelength Modulation Spectroscopy)多組分反演方法,利用該方法實(shí)現(xiàn)了 CH4和N2O濃度準(zhǔn)確測量,測量誤差均小于5%,驗(yàn)證了該消除交叉干擾方法的可行性。在WMS免標(biāo)定擬合算法中,通過模擬的方法并結(jié)合實(shí)際測量的激光器頻率和強(qiáng)度響應(yīng),細(xì)致的研究了激光器的非線性頻率響應(yīng)與強(qiáng)度非線性響應(yīng)對(duì)諧波信號(hào)的影響。將測量的無吸收光強(qiáng)信號(hào)與準(zhǔn)確的激光器頻率響應(yīng)模型相結(jié)合,優(yōu)化了基于吸收線型的免標(biāo)定濃度反演模型,采用無吸收的光強(qiáng)信號(hào)即避免了原有算法模型中非常規(guī)強(qiáng)度響應(yīng)情況下(尤其非線性響應(yīng)顯著)準(zhǔn)確的強(qiáng)度解析模型的建立問題,包含了所有的光強(qiáng)信息(非線性響應(yīng)特性、寄生的無法消除的干涉噪聲、背景吸收特征等);采用包含一階和二階頻率響應(yīng)項(xiàng)及其時(shí)間依賴系數(shù)的激光器頻率響應(yīng)模型,實(shí)現(xiàn)了 v(t)的準(zhǔn)確測量,解決了原有常規(guī)激光器頻率響應(yīng)模型的應(yīng)用局限問題,使該算法模型適于非線性顯著或非常規(guī)強(qiáng)度響應(yīng)情況,更具普適性。以CH4為例,對(duì)該免標(biāo)定方法進(jìn)行了很好的驗(yàn)證,在濃度為60～1200ppm*m(A～0.029～0.57cm-1)范圍內(nèi),WMS免標(biāo)定擬合殘差均小于2%,反演濃度線性度達(dá)到0.99996。在測量系統(tǒng)設(shè)計(jì)與濃度反演算法的研究基礎(chǔ)上,測試與分析了該測量系統(tǒng)的精度、穩(wěn)定性、線性度及檢測限等性能指標(biāo),測試結(jié)果表明該系統(tǒng)完全滿足環(huán)境大氣CH4和N20同時(shí)在線測量的需求。利用該測量系統(tǒng),在合肥科學(xué)島進(jìn)行了外場實(shí)驗(yàn),實(shí)現(xiàn)了環(huán)境大氣CH4和N2O的連續(xù)高靈敏監(jiān)測(光程690m),為不同生態(tài)環(huán)境尺度不同時(shí)間分辨下的溫室氣體高靈敏測量奠定了基礎(chǔ)。
[Abstract]:The concentration monitoring of different space and time scale in the complex ecological environment is the basis of understanding the greenhouse gas source and sink. At present, the technical means to adapt to the long-term continuous monitoring of the greenhouse gases in the ecological environment are still to be studied. Tunable diode laser absorption spectroscopy (Tunable Diode Laser Absorption Spectroscopy, TDLAS) is a non intrusive spectral measurement technology, has the characteristics of high selectivity, high sensitivity, high resolution, and mid infrared quantum cascade lasers currently emerging (Quantum Cascade Laser, QCL) combination, can realize the "fundamental" molecular absorption spectrum the measurement, further improve the detection sensitivity, to achieve regional environmental monitoring of greenhouse gas demand. In the infrared wavelength modulation TDLAS technology this paper deeply studies the long open path design, and integrates a set of long path CH4 and N20 continuous monitoring system, studied the spectral inversion algorithm of multi-component gas interference, to achieve a variety of greenhouse gases, high precision and fast continuous monitoring. This paper chooses two major greenhouse gases in the atmosphere of CH4 and N20 as the target gas, the atmospheric environment has been simulated and analyzed the absorption spectrum by using HITRAN database, 1275cm-1 CH4 and N2O near the adjacent absorption lines are selected to achieve a single laser double component measurement. The modulation characteristics of the 1275cm-1 band CW-QCL laser are studied, and the modulation parameters are optimized with the actual measurement environment. In the mechanical design process, the use of two to solve the long path infrared dichroic mirror (kilometers) multi beam coaxial coupling problem, design a reflective off-axis laser collimating structure and off-axis parabolic mirror open optical transceiver structure based on optical monitoring of the long path to achieve the open kilometers. In this paper, a multi component spectral density inversion algorithm based on calibration and demarcation is studied in this paper. Based on the calibration method, first proposed the multiple linear fitting calibration based on WMS (Wavelength Modulation Spectroscopy) multi component inversion method, realizes the accurate measurement of CH4 and N2O concentration by using this method, the measurement error is less than 5%, verified the feasibility of the method to eliminate interference. In the WMS calibration free algorithm, the influence of nonlinear frequency response and intensity nonlinear response of laser on harmonic signal is studied in detail by simulating method and combining with the measured frequency and intensity response of laser. The absorption intensity signal and the laser frequency response model combined with accurate measurement, optimize the calibration free concentration inversion model based on linear absorption, the absorption intensity signal of avoiding the conventional strength response under the situation of the original algorithm in the model (especially the nonlinear response significantly) establish strength accurate analytical models, including all the light intensity (nonlinear response characteristics, can eliminate the parasitic interference noise, background absorption characteristics); the laser frequency contains one order and two order frequency response and time dependent coefficient of response model, implementation of V (T) of the accurate measurement, to solve the problem of the original application limitations of conventional lasers the frequency response model, the algorithm model is suitable for nonlinear or non conventional strength significantly in response to the situation, has more universality. Taking CH4 as an example, the calibration method is verified well. Within the range of 60 ~ 1200ppm*m (A ~ 0.029 ~ 0.57cm-1), the WMS calibration free residuals are less than 2%, and the inversion concentration linearity reaches 0.99996. Based on the research of measurement system design and concentration inversion algorithm, the accuracy, stability, linearity and detection limit of the measurement system are tested and analyzed. The test results show that the system fully meets the online measurement needs of CH4 and N20 in the ambient air. Based on the measurement system, outfield experiments were carried out in Hefei Science Island to achieve continuous high-sensitivity monitoring of CH4 and N2O in ambient air (690m), which laid the foundation for high-sensitivity measurement of greenhouse gases under different environmental scales and time scales.
【學(xué)位授予單位】：中國科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：O433;TN248

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 洪海濤,俞樸,葉聲華;光纖干涉測距中光程定位的研究[J];光學(xué)學(xué)報(bào);2000年02期

2 李莉;光程差計(jì)算中的近似問題[J];大學(xué)物理;2002年04期

3 劉博學(xué);干涉中光程差的計(jì)算[J];延邊大學(xué)學(xué)報(bào)(自然科學(xué)版);2004年04期

4 江立輝;蔡春潮;梁建波;彭廣生;張紅;鄧誠先;;差動(dòng)光程差倍增法測量微小位移[J];物理實(shí)驗(yàn);2009年06期

5 廖臘梅;賀健;張慶國;;光線通過傅里葉變換紅外光譜儀的光程差分析[J];紅外;2011年12期

6 韓雁冰;羅紅雷;李慧玲;;淺談“光程”概念的引入[J];教育教學(xué)論壇;2012年09期

7 張尹馨;楊懷棟;黃戰(zhàn)華;金國藩;;離面準(zhǔn)李特洛色散光路的光程差[J];光譜學(xué)與光譜分析;2013年07期

8 森火;;雜亂光程波動(dòng)對(duì)激光測距精度的影響[J];激光與紅外;1978年08期

9 朱若谷;用矩陣方法討論穩(wěn)定平凹法布里-珀羅共振腔的失調(diào)對(duì)光程差影響[J];光學(xué)學(xué)報(bào);1982年06期

10 張武;張廣成;羅建;;應(yīng)用顯微激光分析儀精密測量透明材料的光程差[J];實(shí)驗(yàn)力學(xué);1991年04期

相關(guān)會(huì)議論文 前4條

1 鄭國梁;李玲;陶科玉;呂雅莉;;光程概念在基礎(chǔ)光學(xué)教學(xué)中的重要性[A];中國光學(xué)學(xué)會(huì)2011年學(xué)術(shù)大會(huì)摘要集[C];2011年

2 張記龍;陳友華;王志斌;景寧;魏海潮;趙冬娥;;高光程差彈光調(diào)制干涉具動(dòng)態(tài)諧振模型建立與分析[A];中國光學(xué)學(xué)會(huì)2011年學(xué)術(shù)大會(huì)摘要集[C];2011年

3 李錫善;李萍;;光學(xué)介質(zhì)中的微小光程差測量——光學(xué)材料測量技術(shù)發(fā)展和展望[A];第十一屆全國光學(xué)測試學(xué)術(shù)討論會(huì)論文（摘要集）[C];2006年

4 劉子健;郭俐;;OPSIS長光程儀與API點(diǎn)式SO_2、NO_2儀比對(duì)研究及盆地氣侯對(duì)長光程儀影響分析[A];四川省第十一次環(huán)境監(jiān)測學(xué)術(shù)交流會(huì)論文集[C];2010年

相關(guān)博士學(xué)位論文 前3條

1 魏敏;基于CW-QCL的長光程溫度氣體高靈敏檢測方法研究[D];中國科學(xué)技術(shù)大學(xué);2017年

2 張亮;基于游標(biāo)效應(yīng)和光程差放大的光纖傳感增敏機(jī)理研究[D];華中科技大學(xué);2014年

3 孟婕;多普勒光學(xué)相干層析成像方法與應(yīng)用研究[D];浙江大學(xué);2010年

相關(guān)碩士學(xué)位論文 前3條

1 李付廣;碟片激光晶體熱畸變特性的光學(xué)診斷與分析[D];華中科技大學(xué);2014年

2 張瑞;雙PEMs差頻調(diào)制型傅里葉—貝塞爾變換光譜測量技術(shù)研究[D];中北大學(xué);2014年

3 鄭偉;基于FTIR的環(huán)境氣體監(jiān)測系統(tǒng)研究[D];天津大學(xué);2006年

，

本文編號(hào)：1343910