【摘要】：目前,國內(nèi)煤礦和家庭天然氣爆炸的情況時(shí)有發(fā)生,給國家和個(gè)人的財(cái)產(chǎn)造成了巨大的損失,因此甲烷氣體濃度的檢測一直以來都是備受關(guān)注的焦點(diǎn)問題。煤礦、城市地下管道和排污管道等檢測環(huán)境,使其檢測具有很大的復(fù)雜性和艱難性。為了能夠在復(fù)雜的環(huán)境下實(shí)現(xiàn)甲烷氣體濃度的高精度和高穩(wěn)定性檢測,設(shè)計(jì)出基于光譜吸收原理的光纖甲烷檢測系統(tǒng),并提出用鋸齒波調(diào)制半波掃描的方法進(jìn)行檢測,實(shí)現(xiàn)在復(fù)雜條件下進(jìn)行高精度和高穩(wěn)定性測量的特性。系統(tǒng)采用分布式測量,用一個(gè)光源同時(shí)對多點(diǎn)進(jìn)行實(shí)時(shí)在線的監(jiān)測,大大降低了成本;分布式的實(shí)現(xiàn)可以構(gòu)成分布式網(wǎng)絡(luò),能夠?qū)ΡO(jiān)測區(qū)域進(jìn)行更加全面的測量。首先,以檢測的基本原理和氣體的吸收線型為基礎(chǔ),確定了系統(tǒng)的基本檢測方式,即鋸齒波調(diào)制半波掃描的檢測方法。根據(jù)甲烷氣體的吸收譜圖,確定了氣體的吸收譜線位置。其次,通過系統(tǒng)的檢測方法,結(jié)合實(shí)際情況,給出了系統(tǒng)的器件選型原則,確定了該系統(tǒng)各個(gè)模塊的選型規(guī)則;結(jié)合系統(tǒng)的選型規(guī)則,設(shè)計(jì)出系統(tǒng)的硬件電路部分,并根據(jù)硬件電路需求的功能設(shè)計(jì)出系統(tǒng)的軟件功能模塊。并根據(jù)分布式的實(shí)現(xiàn)原理,設(shè)計(jì)并實(shí)現(xiàn)了系統(tǒng)的分布式。再次,通過研究檢測過程中氣體濃度的分布規(guī)律,提出了利用卡爾曼濾波算法來提高檢測的穩(wěn)定性和精度,并驗(yàn)證了其可行性。最后,給出了整個(gè)系統(tǒng)的性能指標(biāo)。該系統(tǒng)采用鋸齒波調(diào)制的半波掃描方式,可以準(zhǔn)確測得甲烷氣體濃度;測量范圍為0%-9.99%,精度為10ppm,穩(wěn)定性為0.01%。高低溫測試表明該系統(tǒng)經(jīng)在復(fù)雜環(huán)境下受溫度影響小,精度高,穩(wěn)定性好,抗干擾能力強(qiáng)。
[Abstract]:At present, the explosion of natural gas in domestic coal mines and households has occurred from time to time, which has caused great losses to the property of countries and individuals, so the detection of methane gas concentration has always been the focus of attention. The detection environment of coal mine, urban underground pipeline and sewerage pipeline makes it very complex and difficult. In order to realize the high precision and stability detection of methane gas concentration in complex environment, an optical fiber methane detection system based on spectral absorption principle is designed, and the method of sawtooth wave modulation half wave scanning is proposed to realize the characteristics of high precision and high stability measurement under complex conditions. The system adopts distributed measurement and real-time online monitoring of multiple points with one light source at the same time, which greatly reduces the cost, and the distributed implementation can form a distributed network and can measure the monitoring area more comprehensively. Firstly, based on the basic principle of detection and the absorption line of gas, the basic detection method of the system, that is, the detection method of sawtooth wave modulation half-wave scanning, is determined. According to the absorption spectrum of methane gas, the position of absorption spectrum line of gas is determined. Secondly, through the detection method of the system, combined with the actual situation, the principle of device selection of the system is given, and the selection rules of each module of the system are determined. Combined with the selection rules of the system, the hardware circuit part of the system is designed, and the software function module of the system is designed according to the function of the hardware circuit. According to the principle of distributed implementation, the distributed system is designed and implemented. Thirdly, by studying the distribution law of gas concentration in the detection process, the Kalman filter algorithm is proposed to improve the stability and accuracy of the detection, and its feasibility is verified. Finally, the performance index of the whole system is given. The methane gas concentration can be accurately measured by sawtooth wave modulation half wave scanning, the measurement range is 0% 鈮，

本文編號：2504496