ABSTRACT

As the depth of coal mining continues to increase, the weight of the overlying strata and the ground stress on the residual coal in goaves also increase. At the same time, the temperature of the coal rocks continues to rise, and the high ground temperature environment of the mining and heading faces becomes more severe. As a result, coal oxidation and spontaneous combustion disasters become more prominent. In this work, an anaerobic heating experiment of coal under the thermal-mechanical coupling effect was performed. The effects of thermal-mechanical coupling on the thermal stability of coal were studied by analyzing parameters such as the heat flow peak temperature, endothermic peak value, heat absorption, and activation energy. The results showed that the heat flow peak temperature exhibited hysteresis as the initial temperature and the initial stress increased. At the same time, the endothermic heat flow peak value and the heat absorption decreased. Under the same initial stress, the activation energy gradually decreased as the initial temperature of the coal sample increased; the higher the initial stress, the lower the decrease in the activation energy. At the same initial temperature, the activation energy first increased and then decreased as the initial stress increased; the higher the initial temperature, the more sensitive this change in the activation energy was to stress. In this study, the influence of thermal-mechanical coupling on the thermal stability of coal was obtained. This work provides on-site guidance for the prevention and control of spontaneous coal combustion in deep mining.

摘要

随着采煤深度的不断增加，上覆地层的重量和采空区剩余煤的地应力也随之增加。同时，煤岩温度不断升高，采掘面高地温环境更加严峻。因此，煤的氧化和自燃灾害更加突出。在这项工作中，进行了热-机械耦合效应下煤的厌氧加热实验。通过分析热流峰值温度、吸热峰值、吸热和活化能等参数，研究了热力耦合对煤热稳​​定性的影响。结果表明，随着初始温度和初始应力的增加，热流峰值温度呈现滞后现象。同时，吸热热流峰值和吸热量降低。在相同的初始应力下，随着煤样初始温度的升高，活化能逐渐降低；初始应力越高，活化能的降低越小。在相同的初始温度下，随着初始应力的增大，活化能先增大后减小；初始温度越高，活化能的这种变化对应力越敏感。在这项研究中，获得了热力耦合对煤热稳​​定性的影响。