Study On The Influence Of Atmospheric Pressure Change On Gas Emission In The Goaf Of Laohutai Mine And Its Prevention And Control Technology

Gas accidents are the main body of coal mine accidents.Many gas accidents at home and abroad occurred during the sharp drop in atmospheric pressure.In order to clarify the mechanism of atmospheric pressure changes affecting gas emission,using the Laohutai Mine as the research background.Analyze the variation of atmospheric pressure throughout the year and the characteristics of atmospheric pressure variation during the occurrence of abnormal gas emission,and it was demonstrated that the decrease in atmospheric pressure was a gas anomaly in the area.The experimental study on the relative changes of the static pressure of the gas in the ground surface,coal mining face,and goaf.The evolution of gas concentration in goafs during atmospheric pressure fluctuations was explored.Analyzed and evaluate the existing prevention and control technology system of Laohutai Mine and put forward optimization suggestions.Studies have shown that the change in atmospheric pressure directly affects the static pressure of gas in the working face and the goaf,and its rapid and continuous decrease is the main cause of abnormal gas emission.Analyze the change of air pressure in 2016 and the change of air pressure during the occurrence of abnormal gas emission.The results show that the air pressure in the region is relatively high and fluctuating sharply in the spring and winter seasons,especially in January,February,November,and December.At that time,atmospheric pressure changes will cause significant gas outbursts.By analyzing 6 large gas anomalous gas outbursts in Laohutai area,it is concluded that when the maximum pressure drop exceeds 600 Pa for a duration of more than 14 hours,and the maximum pressure drop during the period exceeds 150 Pa,it is considered that an abnormal gas outburst may occur.The experimental study found that the surface atmospheric pressure and the working surface air pressure change synchronously,but the changes in the static pressure of gas in the deep Part of the goaf have obvious hysteresis comPared with the former two.Due to the hysteresis,a pressure difference is generated in and around the goaf.This pressure difference causes a "breathing" state change in the goaf.When the air pressure in the working face decreases,the gas concentration in the measuring points in the goaf increases,showing a significant negative correlation,and there is a significant negative correlation between tow;and the greater the rate of atmospheric pressure drop,the faster the gas concentration in the goaf increases,and the two are obvious.Positive correlation.The combined effect of pressure difference and concentration difference will cause gas in the goaf to flow to the working face.The magnitude and duration of the pressure drop are the main factors affecting the amount of gas emission.According to the research,Laohutai Mine should comprehensively analyze the abnormal gas emission data,optimize the atmospheric pressure monitoring and early warning value,strengthen the construction of gas drainage system,grasp the timing and threshold of air regulation,and take measures to reduce air leakage in the goaf.It is suggested that on the premise of meeting the requirements for prevention and control of coal spontaneous combustion of coal and comprehensively judging the required air volume for safe production of the mine,appropriately increase the mine ventilation resistance,reduce the proportion of natural wind pressure change to the total wind resistance of the mine,weaken the imPact of atmospheric pressure changes on the mine ventilation system,and enhance Ventilation system stability to ensure safe mine production.The present dissertation has 31 Figures,13 tables and 81 references.