Experimental Study on the Effect of Air Volume on Coal Spontaneous Combustion Limit Parameters

In order to study the effect of air volume on coal spontaneous combustion limit parameters, we use coal spontaneous combustion program temperature test device to make this study, the oxygen consumption rate, CO, CO₂ production rate and exothermic strength of coal samples under five different air volume conditions were analyzed. We calculate the coal spontaneous combustion limit parameters and analyze the variation law on this basis. Study shows that the different air supply leads to different degrees of oxidative exothermic strength of the coal, in the case of the air flow of 60 mL/min, the exothermic intensity of the medium reaches a maximum; the variation of spontaneous combustion limit parameters of coal can be divided into two stages: the air volume is less than 40 mL/min, the minimum floating coal thickness and the lower oxygen concentration of coal samples decrease with the increase of air volume, the upper air leakage intensity of the coal sample increases with the increase of the air volume; when the air volume is more than 40 mL/min, the minimum floating coal thickness and the lower limit oxygen concentration increase linearly with the increase of air volume, and the upper limit air leakage intensity decreases linearly with the increase of air volume. We need to pay attention to the regulation of the air volume in the underground mining process, so that the ignition parameters of coal are not conducive to the development direction of spontaneous combustion.