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Numerical Simulation of Methane Distribution and Sensor Placement in 2-Dimension Roadway 被引量:5
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作者 SUN Ji-ping TANG Liang CHEN Wei WANG Fu-zeng 《Journal of China University of Mining and Technology》 EI 2007年第3期372-375,共4页
In order to provide a theoretical basis for methane sensor placement in the vertical direction of a tunnel,the software Fluent was used to simulate methane distribution. A geometric roadway model was established and d... In order to provide a theoretical basis for methane sensor placement in the vertical direction of a tunnel,the software Fluent was used to simulate methane distribution. A geometric roadway model was established and divided by grids. Methane distribution in both level and vertical sections was simulated using a realizable k-ε model with the Fluent software according to a conservation equation in a turbulent state,a turbulent kinetic energy equation and a turbulent dissipation rate equation. The realizable k-ε model and the Fluent software were used to simulate methane distribution according to the principle of the conservation equation in a state of turbulent flow. The results show that after overflow-ing,a methane level with a certain thickness is formed. Methane density curves at three specific levels were internally consistent and methane density at higher levels is denser than that at lower levels. Methane distribution becomes thinner in the direction of wind and methane in the vertical direction becomes uniform if wind speed is high. The distance be-tween sensors and roof should be less than 300 mm which is in agreement with mine safety regulations. 展开更多
关键词 numerical simulation methane sensor placement methane distribution realizable k-ε model
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Novel Optical Fiber Gas Sensor for On-line Measurement of Methane
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作者 WANGShu-tao CHERen-sheng +1 位作者 LIUJin WANGYu-tian 《Semiconductor Photonics and Technology》 CAS 2004年第2期141-144,共4页
Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measu... Based on analysis of near infrared spectral absorption of methane,absorption type optical fiber methane gas sensor with high sensitivity using DFB LD as a source is demonstrated. Light source modulation harmonic measurement is presented in this paper. In order to eliminate the noise, the ratio of the fundamental and second-harmonic signals is used. The mathematical model of gas concentration harmonic measurement is built up.The detection result of methane concentration is also shown. Experiments have proved a sensitivity of 28×10-6. 展开更多
关键词 Gas sensor METHANE MODULATION Harmonic measurement
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