Impact of External Atmospheric Pressure Changes on the Behavior of Gas Emission in Mines

Abstract

With the rapid development of industry in China, the scale of coal mining continues to expand, leading to an increase in safety hazards and frequent accidents. Among these, gas overrun accidents account for a significant proportion, and changes in atmospheric pressure are a major factor affecting the outburst of coal mine gas. This paper takes a mine in Hebei Province, China, as the research object, combining on-site data detection with numerical simulation methods to explore the influence of atmospheric pressure changes on underground air pressure and gas emission. The results show that changes in atmospheric pressure are synchronized with changes in underground air pressure, and the rate of change affects the amount of gas emitted. When the rate of pressure decrease is below 0.04 KPa/h, the impact is slower, and the peak time of gas emission is later than the time of minimum pressure. Simulation results indicate that the pressure difference caused by changes in atmospheric pressure is transferred to the underground air pressure, affecting the distribution of methane at the working face and the range of air leakage in the goaf. The greater the pressure difference, the higher the concentration of methane at the working face, the greater the air leakage in the goaf, and the more gas brought from the deep part of the goaf to the working face. These findings are of great significance for understanding the mechanism of gas emission and preventing gas accidents.