Dissertation > Industrial Technology > Automation technology,computer technology > Automation technology and equipment > Automation components,parts > Transmitter ( converter),the sensor

Research on Fiber Gas Sensing Technology and Its Applications on Coal Mine Safety

Author NiJiaSheng
Tutor ChangJun;LiuTongYu
School Shandong University
Course Electronics and Communication Engineering
Keywords Fiber sensing Spectrum absorption Coal mine safety Methane detection Trace gas detection Gob spontaneous combustion
Type Master's thesis
Year 2009
Downloads 164
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According to quantum mechanics theory, energy distribution of external nuclear electronics are discontinuous, and electrons would not sent out electromagnetic wave when it moving on its obit, unless energy of electronic jump from E1 to E2, which is called transition. Electronic energy transition from high to low would makes it sent out a certain frequency photonic, which exhibits a property of spectrum emission. On the contrary, it exhibits a property of spectrum absorption in the transition from low to high when the electronic absorb a certain frequency photonic. Molecular are composed by atomics. Only the photonic energy is equal to the energy difference of some two molecular energy levels, it would be absorbed by gas molecular. So, a certain gas has its certain absorption wavelength, and by this, we can also distinguish the different gases. By the Beer-Lamber law we can know, that there are certain relationships between the light absorption and gas concentration. By this we can achieve detection of the gas.Safety accidents in coal mines caused extensive concern recently. How to improve mining safety is very important. The methane explosion and methane outburst are the most serious problems in the coal safety accidents. The traditional technology does not satisfy the safety situation now. So that implementation of fiber methane sensor, especially remote, no electric charges, becomes very important.Goaf spontaneous combustion takes another great influence to the mining. Goaf spontaneous combustion usually effect normal coal mine production. Once fire occurred, tremendous economic loss will occurred. According to the fire gas detection, the article design and implement a spontaneous combustion gas detecting system.The article introduces gas detection and its applications in the coalmine at the first chapter. In the second chapter, basic principle of absorption-type gas detection is described. In the third chapter, four schemes of CH4 detection are described. Each scheme is detailed described and mass experimental data is provided also. In the fourth chapter, according to the detection of CH4 and its site application, paper gives out a detailed description. Practical data from demonstration project is also analyzed. A new design idea that improved front contents technique is proposed in the fifth chapter. Harmonics technology and phase locked amplified technology are used to realized ultra high sensitivity detection of trace gases. In the sixth chapter, application of fiber trace gas sensor used in coalmine is detailed described. Spontaneous combustion online forecast is realized. In the seventh chapter, it emphatically introduces sensor’s design, which is important for the application. Concrete design of dust proof and moisture proof are put forward. At last, the whole work of article is summarized, and the next work is also briefly introduced.Combining with actual demands of coal mine safety, the article has reallized methane and trace gas detection with fiber optical sensing technology. And those sensors are used on site. Demonstration and application experiment used fiber optic sensors in the coal mine are reported and well realized firstly. In the process of designing and debugging, stability and sensitivity are fully considered by author. Fiber optical sensors that can be applied practically are mailly studied. The system not only has academic value, but also has practical industrial significance.

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