The variation of environmental parameters after gas explosion in semi-closed pipeline

The understanding of the laws of environmental parameters in the later stage of gas explosion in coal mine roadways is of great significance for the prevention and control of derivative disasters and post-disaster rescue. To further comprehend this, the article performed explosion experiments under different gas concentrations in a semi-closed pipeline, focusing on the continuously varied rules of environmental parameters (pressure, temperature, humidity) after a gas explosion. The results showed that the pressure at the open end of the pipeline exhibited a relatively remarkable upward tendency when it arrived in the valley. By comparing with the pressure monitored in the middle of the pipeline, it was concluded that there was a more apparent air reflux phenomenon at the open end. The changes in temperature and humidity were roughly similar, both had a relatively distinct increase after an explosion, with the temperature rising by 7.2% on average and the humidity increasing by 2.7% on average. When the methane concentration was 9.5%, its pressure peaks, temperature peak, and humidity peak were all the maximum. Moreover, the phenomenon of air reflux was also the earliest, with 3.1 seconds, which demonstrated that the closer to the gas equivalent concentration, the more sufficient and violent the explosion reaction, the greater the possibility of secondary accidents. The research can provide a theoretical basis for preventing derived hazards (coal dust explosions, secondary explosions) and reducing the effect of derived hazards.