New exploration on the goaf inerting with hidden fire source under CO2 injection volume of adsorption compensation

To strengthen the rationality of the design of CO 2 injection volume in goaf, a framework is proposed to study goaf inerting characteristics with hidden fire sources under CO 2 injection volume of adsorption compensation. The zone of hidden fire source is determined by similar simulation experiment of coal spontaneous combustion on a working face of coal mine. The range of injection volume without adsorption is calculated theoretically. A three-dimensional initial flow field model of coal spontaneous combustion is established combined with field measurement. The error of oxidation zone width is 3.64 %, which verifies the reliability of model. The influence of injection volume on the inerting effect in goaf is studied, and optimal injection volume without adsorption is 1000 m 3 /h. Based on the relationship between adsorption capacity and temperature, a quantization model of injection volume with adsorption compensation is established. The maximum dissipation ratio is then proposed. The optimal injection volume after adsorption compensation is calculated. The results show that intermittent injection of gaseous CO 2 is recommended under simulated conditions. The maximum dissipation ratio is 1/4, and the CO 2 injection volume compensated by adsorption is 1333 m 3 /h. The research results can provide theoretical guidance for the optimization of CO 2 inerting parameters in goaf.