为研究粒度对煤自燃热动力学特征和极限参数的影响，采用程序升温系统分别对5种不同粒度煤样（0~<0.9、0.9~<3、3~<5、5~<7、7~10 mm）的氧化过程进行测试分析，确定了不同氧化阶段的表观活化能，量化计算了煤自燃极限参数变化特征，揭示粒度对煤自燃的作用机理。结果表明：煤样表观活化能与其粒度呈正相关关系，粒度为0~<0.9、0.9~<3、3~<5、5~<7、7~10 mm的煤样，其平均表观活化能分别为49.48、53.56、57.01、59.81、60.83 kJ/mol；同一粒度煤样不同阶段的表观活化能也不相同，均随氧化反应深入而降低，且高温阶段的表观活化能小于其低温阶段；随着煤温升高，最小浮煤厚度和下限氧气体积分数呈现先增大后减小的趋势，而上限漏风强度则相反；煤样粒度与最小浮煤厚度和下限氧气体积分数呈正相关关系，与上限漏风强度呈负相关关系，煤样粒度越小，其最小浮煤厚度和下限氧气体积分数越小，上限漏风强度越高，更容易发生自燃。

In order to study the effect of particle size on the thermodynamic characteristics and limiting parameters of coal spontaneous combustion, the oxidation process of coal samples of five different particle sizes (0-<0.9, 0.9-<3, 3-<5, 5-<7, 7-10 mm) was tested and analyzed using the programmed heating system, and the apparent activation energy of the different oxidation phases were determined, and the change characteristics of the limiting parameters of coal spontaneous combustion were quantitatively calculated, so that the mechanism of particle size on the spontaneous combustion of coal could be revealed. The results showed that the apparent activation energy of the coal sample was positively correlated with its particle size, and the average apparent activation energy of coal sample with the particle size of 0-<0.9, 0.9-<3, 3-<5, 5-<7, 7-10 mm is 49.48, 53.56, 57.01, 59.81, 60.83 kJ/mol, respectively. The apparent activation energy of coal sample with the same particle size at different stages is also different, which decreases with the deepening of oxidation reaction, and the apparent activation energy at high temperature stage is lower than that at low temperature stage; as the coal temperature increases, the minimum floating coal thickness and lower limit oxygen volume fraction show a trend of first increasing and then decreasing, while the upper limit air leakage intensity is the opposite; the particle size of coal sample is positively correlated with the minimum floating coal thickness and lower limit oxygen volume fraction, and negatively correlated with the upper limit air leakage intensity. The smaller the particle size of coal sample, the smaller its minimum floating coal thickness and lower limit oxygen volume fraction, and the higher the upper air leakage intensity, the more prone to spontaneous combustion.