A study on source identification of gas explosion in coal mines based on gas concentration

Fuel ◽  
2021 ◽  
Vol 290 ◽  
pp. 120053
Author(s):  
Baiwei Lei ◽  
Chenguang Zhao ◽  
Binbin He ◽  
Bing Wu
2014 ◽  
Vol 66 (6) ◽  
pp. 671-677
Author(s):  
Qingrui Meng

Purpose – The aim of this work is to reveal the temperature rise characteristics of the new designed disc during a braking process. In underground coal mines, the highest temperature of the disc brake used for inclined downward belt conveyors should be < 150 to prevent gas explosion during a braking process. To meet the requirements, a new type of disc was designed. Design/methodology/approach – By using ANSYS software, the disc surface and interior temperature rise variations, effect of braking time and running speed on temperature rise are analyzed numerically. Findings – The results show that the new designed disc can meet the coal mines’ requirements well, during the braking process the disc surface temperature increases at first and then decreases, there is an obvious temperature gradient in the axial direction; when running speed increases to two times of the rated one, the highest temperature nearly reaches 150; and a prolonged braking time can decrease the highest temperature effectively. Research limitations/implications – It indicates that the disc brake should act as earlier as possible to slow down the belt conveyor when overspeed occurs; and when the running speed increases to two times of the rated one, the braking time must be prolonged to prevent gas explosion. Originality/value – Research findings of this paper provides theoretical basis for the practical applications of the disc brake used for inclined downward belt conveyor.


2016 ◽  
Vol 23 (s1) ◽  
pp. 131-137 ◽  
Author(s):  
Baiwei Lei ◽  
Bing Wu ◽  
Yatong Zhao ◽  
Muhammad Aqeel Ashraf

Abstract In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84) which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation.


2011 ◽  
Vol 71-78 ◽  
pp. 4848-4851
Author(s):  
Fan Mao Meng ◽  
Zhi Chao Liu ◽  
Zhi Zhong Liu

The water mist is an economical and environmental agent for gas explosion suppression. It can be applied in the commonly gas concentration zones and the gas accumulation zones which is difficult to reduce the concentration of methane gas. By numerical analysis, this paper studies the effect of the direction and the number of the nozzles, and the distance form the nozzles to the wall at X direction in upper corner in coal mine. For gas explosion suppression in upper corner, it can use one nozzle which direction is same as the wind and the distance is 2m.


2013 ◽  
Vol 706-708 ◽  
pp. 1805-1809
Author(s):  
Xiao Yan Gong ◽  
Jun Guo ◽  
He Xue ◽  
Dong Hui Yan ◽  
Zhe Wu

In order to predict accurately gas concentration and design ventilation scheme in driving ventilation process under different gas emission in coal mine, based on the analysis of various ventilation factors, the prediction model structure of gas concentration for driving ventilation was designed based on RBF and BP neural network in this paper. Then MATLAB software and the observation data obtained from the coal mine sites were used to compare and analyze the prediction errors of two models, and a RBF neural network model with higher prediction precision was obtained. After that, the prediction model was used for practical application research on the gas concentration of the heading face in concrete coal mines. The research shows that the settled prediction model can not only predict the gas concentration precisely of driving ventilation, but also provide a certain theory basis for different driving ventilation equipment layout and parameters configuration in the driving ventilation process of coal mines.


2019 ◽  
Vol 13 (4) ◽  
pp. 121-128
Author(s):  
N. M. Shahani ◽  
M. J. Sajid ◽  
X Zheng ◽  
I. M. Jiskani ◽  
M. A. Brohi ◽  
...  

2020 ◽  
Vol 135 ◽  
pp. 207-218 ◽  
Author(s):  
Min Li ◽  
Hetang Wang ◽  
Deming Wang ◽  
Zhenlu Shao ◽  
Shan He

2013 ◽  
Vol 303-306 ◽  
pp. 42-44
Author(s):  
Hai Chen Li

Coal Face Gas Concentration Overrun Is the Leading Cause of China Coal Mine Fatal Gas Explosion Accidents Reasons. Therefore, Research and Development of Rapid Detection of Gas Sensor Can Avoid Gas Explosion Accident Key. this Paper Studies the Al2o3 Nanometer Powder Preparation Technology, by Doping Rare Earth Material so that the Gas Sensor Detection Element Surface Area Was Greatly Improved; its Sensitivity and Stability Are Greatly Improved. According to the Test Results Show that, the Rapid Gas Sensor for Methane Reaction Time Is 6 Seconds, Recovery Time of 8 Seconds.


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