Analysis of outburst instability tendency of coal containing methane based on energy theory

In order to analyze the influence of unsteady diffusion characteristics of tectonic coal on energy instability, the steady and unsteady gas diffusion models were used to establish the functional relationship between the initial gas diffusion coefficient and pressure of intact coal and tectonic coal. Based on the existing energy formula, the calculation models of adsorbed gas and free gas expansion energy were established. The relationship between buried depth and outburst energy was analyzed, and the instability tendency of outburst energy in coal under different buried depths was discussed. The critical buried depth of outburst in the tectonic coal seam was 190 m, and the field gas dynamic phenomenon also verified the conclusion.