Simulation study on disaster evolution of ventilation system during coal and gas outburst

Abstract In order to solve the serious secondary disasters of the gas overrun or gas explosion, which is caused by coal and gas outburst in mine. In this paper, the equations of fluid transients, convection diffusion and source-containing ventilation network were established respectively to research the dynamic effect and gas migration process of gas outburst in ventilation system of coal mine. In order to research the unsteady movement characteristics of mine airflow under the joint action of gas outburst source flow power and fan ventilation, we completed the experiment of ventilation pipe network system for gas outburst. The fitting equation of gas dispersion parameters under different wind speeds was obtained, which was used as the simulation calculation parameter. In this paper, NC2.0, one simulation software of coal and gas outburst, was developed, and the 10.27 coal and gas outburst accident in Jiaozuo Jiulishan coal mine was reappeared by it. Throughout the simulation process, unsteady air flow and gas distribution in Jiulishan coal mine after coal and gas outburst were simulated respectively by the given fluid changing curve. The research results indicate that the outburst pressure after coal and gas outburst, which is the main factor leading to the changing airflow, and radiates in the form of wave. The high-intensity air flow from the gas outburst source changes the air flow movement of the mine system, causes over air flow phenomenon in return air roadway, suppresses the air volume in air inlet roadway at the same time. Even countercurrent occurs in severe cases. The research results provide the theoretical basis for disaster prevention and aid, reducing loss and preventing secondary disasters in outburst mine.