【摘要】：基于拉曼散射效應(yīng)的分布式光纖測溫系統(tǒng)是近年來發(fā)展起來的一種新型溫度傳感系統(tǒng),此類系統(tǒng)利用單根傳感光纖就能夠在線測量出沿光纖分布的空間溫度場。與以往傳統(tǒng)的測溫系統(tǒng)相比較,拉曼測溫系統(tǒng)具有較高的空間分辨率和溫度分辨率;能夠?qū)崟r監(jiān)測溫度,每隔一定時間便會刷新一次溫度數(shù)據(jù),保證了數(shù)據(jù)即時有效;此外,系統(tǒng)具有耐腐蝕、抗電磁干擾、防火防爆以及傳輸距離遠等優(yōu)點,使得它與傳統(tǒng)的溫度傳感器區(qū)別開。分布式光纖拉曼測溫系統(tǒng)因其本身具有的獨特優(yōu)勢,已經(jīng)廣泛應(yīng)用于航空航天、工業(yè)現(xiàn)場、公共安全等領(lǐng)域。本文在回顧光纖傳感技術(shù)發(fā)展背景的基礎(chǔ)上,概述了分布式光纖測溫系統(tǒng)的國內(nèi)外研究現(xiàn)狀及發(fā)展趨勢,指出了國產(chǎn)系統(tǒng)存在的不足,確立了本課題的主要研究內(nèi)容。在分析光纖中的后向散射的基礎(chǔ)上,將拉曼散射理論與光時域反射技術(shù)相結(jié)合,提出了分布式光纖拉曼測溫系統(tǒng)的基本原理,通過用Rayleigh光、anti-stokes光以及stokes光分別作為參考光進行計算分析,確定了系統(tǒng)最終選用stokes光作為參考光進行信號解調(diào)。根據(jù)系統(tǒng)設(shè)計要求,本文在計算分析系統(tǒng)所需元器件參數(shù)的基礎(chǔ)上,對系統(tǒng)元器件進行了選型,搭建了分布式光纖拉曼測溫系統(tǒng)。在分析影響系統(tǒng)信噪比因素的基礎(chǔ)上,確立了采用累加平均及小波變換相結(jié)合的方法來提高系統(tǒng)信噪比;根據(jù)信號解調(diào)理論,對解調(diào)方案的正確性進行了實驗驗證;研制了溫度標(biāo)定模塊,采用對不同溫度段溫度分別標(biāo)定的方法,通過對采集到的數(shù)據(jù)進行分析處理,完成了系統(tǒng)溫度標(biāo)定實驗,實現(xiàn)了溫度的測量。為了驗證分段定標(biāo)方案的可行性,文章首先對系統(tǒng)空間分辨率、溫度分辨率、溫度測量精度、響應(yīng)時間、穩(wěn)定性及重復(fù)性分別進行了測試。測試結(jié)果表明:在100℃以內(nèi),系統(tǒng)空間分辨率為1m,溫度分辨率優(yōu)于1℃,溫度測量精度達±1℃,響應(yīng)時間為34s,系統(tǒng)穩(wěn)定可靠、重復(fù)性良好;其次,針對油井、核電監(jiān)測等特殊領(lǐng)域,對高溫區(qū)域溫度的測量進行了探索研究,實現(xiàn)了300℃的測量;最后,對系統(tǒng)主機進行了安裝測試,測試結(jié)果符合要求,據(jù)此完成了一臺性能優(yōu)異且具有一定價格優(yōu)勢的分布式光纖拉曼測溫系統(tǒng)樣機。
[Abstract]:The distributed optical fiber temperature measurement system based on Raman scattering effect is a new temperature sensing system developed in recent years. This kind of system can on-line measure the spatial temperature field along the fiber by using a single sensing fiber. Compared with the traditional temperature measurement system, Raman temperature measurement system has higher spatial resolution and temperature resolution, can monitor temperature in real time, refresh the temperature data every certain time, and ensure the data to be effective immediately. In addition, the system has the advantages of anti-corrosion, anti-electromagnetic interference, anti-fire and explosion-proof and long transmission distance, which makes it separate from the traditional temperature sensor. Distributed fiber Raman temperature measurement system has been widely used in aerospace, industrial field, public safety and other fields because of its unique advantages. On the basis of reviewing the development background of optical fiber sensing technology, this paper summarizes the research status and development trend of distributed optical fiber temperature measurement system at home and abroad, points out the shortcomings of domestic system, and establishes the main research contents of this subject. Based on the analysis of backscattering in optical fiber, the basic principle of distributed fiber Raman temperature measurement system is proposed by combining Raman scattering theory with optical time domain reflectance technique. By using Rayleigh light, The anti-stokes light and the stokes light are calculated and analyzed, and it is determined that the system uses stokes light as the reference light to demodulate the signal. According to the requirements of the system design, on the basis of calculating and analyzing the parameters of the components required by the system, the system components are selected and the distributed fiber Raman temperature measurement system is built. Based on the analysis of the factors affecting the signal-to-noise ratio of the system, the method of combining cumulative average and wavelet transform is established to improve the signal-to-noise ratio of the system, and the correctness of the demodulation scheme is verified experimentally according to the theory of signal demodulation. The temperature calibration module is developed and the system temperature calibration experiment is completed by analyzing and processing the collected data by using the method of calibrating the temperature of different temperature sections respectively. The temperature measurement is realized. In order to verify the feasibility of the piecewise calibration scheme, the spatial resolution, temperature measurement accuracy, response time, stability and repeatability of the system are tested respectively in this paper. The test results show that: within 100 鈩，

本文編號：2329018