Numerical simulation of effect of nitrogen injection on gas explosion hazard in goaf

Abstract

In order to study the effect of nitrogen injection on the gas explosion danger zone in the goaf of high-gas mines, taking the 3235 working face of a coal mine in Anhui Province as an example, the COMSOL multiphysics coupling simulation software was used to establish a model of nitrogen injection in the goaf, and the gas migration laws of goaf under different nitrogen injection flow rates and nitrogen injection positions were analyzed. According to the mathematical principle of linear superposition, the gas explosion hazard area of goaf is divided and its distribution characteristics are analyzed. Through comparative study, it is found that with the increase of nitrogen injection flow in the goaf, the oxygen with the lowest concentration required for the explosion and the methane within the explosion limit have the tendency to move towards the working face and the goaf respectively, and the maximum width and area of the gas explosion hazard area show a trend of decrease. The nitrogen injection position and the hazard area of the volume fraction of oxygen required for a gas explosion showed a negative correlation.

Keywords

• goaf
• gas explosion danger zone
• nitrogen injection flow rate
• nitrogen injection position
• negative correlation