水化煤风干热与自然发火特性实验研究

Experimental Study on Air-drying Heat and Spontaneous Combustion Characteristics of Hydrated Coal

为明确水化煤饱和-风干过程中的自燃-热特性,采用TG-DSC相结合的实验方法,对水化煤风干过程中的不同含水率煤样的热力学参数、活化能、自然发火期的变化规律进行了实验研究。结果表明:水化煤风干过程中其氧化动力学参数一般在低温具有降低-增大-降低的趋势,达高温阶段后风干程度影响不显著;水化煤样粒径降低,吸氧量与放热量增加,特征温度、活化能降低,自然发火期缩短;疏水过程中,自然发火期先减小至较小值后再增大,自然发火期在含水率13.01%~14.87%范围内存在极小值,煤矿采空区安全疏水过程中应根据实际防火布置情况与开采情况合理确定疏水程度,确保遗煤不会因水分过度疏干而加速发展成自燃火灾。

In order to determine the spontaneous combustion and thermal characteristics of hydrated coal during saturation to air drying,the combined experimental method of TG-DSC was adopted to research the thermodynamic parameters,activation energy and spontaneous combustion phase of coal samples with different moisture contents during air-drying of hydrated coal.The results show that the oxidation kinetic parameters of the hydrated coal during air-drying generally have a tendency of decreasing-increasing-decreasing at low temperature,but the influence of air-drying degree after reaching high temperature is not significant;the particle size of hydrated coal decreases,oxygen uptake and heat release increase,characteristic temperature and activation energy decrease,and spontaneous combustion period is shortened;in the process of drainage,spontaneous combustion period reduced to a smaller value and then increased,and the minimum value of spontaneous combustion period exists in the water content of 13.01%-14.87%.In the process of safety drainage of coal mine goaf,the degree of drainage should be reasonably determined according to the actual fire prevention arrangement and mining situation,so as to ensure that the residual coal will not develop into spontaneous fire due to excessive water drying.