为了考察不同湿度条件对煤自燃过程参数及热效应的影响,搭建了湿度可调的精密型空气发生装置,并与煤自燃程序升温氧化装置联用,测定煤自燃过程指标性气体的释放规律;利用热分析设备定量表征不同空气湿度条件下煤自燃热量释放规律;结合数值模拟方法探究空气湿度对煤自燃过程热效应影响。结果表明:通入潮湿空气可显著提高煤样耗氧速率,促进CO和CO2的生成,空气湿度对煤自燃过程热效应呈现出阶段性特征;水分在刚接触到煤体时,短时间内会释放大量的吸附热,促进煤体升温;空气中水分参与煤自燃体系热效应主要通过水的吸附热、煤氧反应热、热对流和热传导4个途径,其中吸附热和导热传热起到主导作用。

In order to investigate the influence of different humidity conditions on the parameters and thermal effect of the process of coal spontaneous combustion, a compact air generator with adjustable humidity was built and used in conjunction with the temperature program oxidation device of coal spontaneous combustion to measure the release law of indicator gas during coal spontaneous combustion process. Thermal analysis equipment was used to quantitatively characterize the law of heat release from spontaneous combustion of coal under different air humidity conditions. The influence of air humidity on the thermal effect of coal spontaneous combustion was studied by numerical simulation method. The results show that the ventilation of moist air can significantly increase the oxygen consumption rate of coal samples and promote the production of CO and CO2. The thermal effect of air humidity on the spontaneous combustion of coal presents stage characteristics. When the moisture in the air first contacts with the coal, it will release a large amount of adsorption heat in a short time, promoting the rise of coal temperature. The moisture in air participates in the thermal effect of coal spontaneous combustion system mainly through four ways: adsorption heat of water, reaction heat of coal oxygen, heat convection and heat conduction, among which the adsorption heat and the conduction heat play leading roles.