Law of gas-solid particle ejection during coal and gas outburst and the classification method of outburst mine risks

Abstract

In order to reveal the evolution law of coal and gas outburst gas-solid particle flow, an analysis method combining field statistical data with numerical simulation data was proposed based on the discrete element numerical simulation method. The development process of gas-solid two-phase flow of coal and gas outburst was studied, and the movement track of coal and gas was revealed. Based on principal component analysis (PCA) and fuzzy comprehensive evaluation (FCE), 27 outburst mines were classified. The research results show that coal and gas outburst can be divided into four stages: coal and gas breaking through crosscut stage, coal and gas mixed impact stage, coal and gas two-phase flow diversion stage and coal and gas outburst attenuation stage; with the development of the outburst, the two-phase flow of coal and gas is divided. Compared with coal particles, the gas movement speed is higher, mainly above the roadway, most coal particles settle to the bottom of the roadway, and a small number of coal particles and gas continue to move forward in coordination, the coal particle movement tracks are more complex than gas; through numerical simulation, the coal throw volume of three outburst mines are 121.5 t, 42.7 t and 320.32 t; according to PCA-FCE comprehensive evaluation, 27 coal and gas outburst mines include 16 general outburst mines and 11 serious outburst mines.

Keywords

• coal and gas outburst
• gas-solid particles
• discrete element
• comprehensive evaluation method
• hazard classification