| In order to study the oxidation characteristics of residual coal in goaf under complex environment, the effects of water immersion degree, air flow rate and exposure time on the spontaneous combustion parameters of coal samples were analyzed by temperature programmed experiment. The correlation between CO production, oxygen consumption rate, heat release intensity, activation energy and temperature was revealed, and the difference of coal spontaneous combustion determination indexes under different environments was quantified. The grey correlation analysis is introduced to clarify the influence weight of each factor on the characteristic parameters of spontaneous combustion. The results show that there is a critical effect of air supply on coal spontaneous combustion. The CO production rate and heat release intensity reach the peak at 120 ml / min, which are 1.8 and 1.5 times higher than those at 180 ml / min, respectively. The soaking time has a non-linear effect. The coal sample soaked for 15 days has the best pore structure and active site, and the maximum exothermic intensity is higher than that of the samples soaked for 5 days and 25 days. Grey correlation analysis showed that the influence weight of air supply was the highest ( correlation degree 0.85 ), which was significantly greater than that of immersion and exposure time. Through the identification of critical parameters and the quantification of weights, the research provides theoretical and data support for the precise prevention and control of spontaneous combustion of residual coal in goaf. |
