水化煤饱和-风干过程的自燃特性实验研究

Experimental study on spontaneous combustion characteristics of hydrated coal during saturation-air drying process

为了掌握水化煤饱和-风干过程中不同风干时间煤样的自燃特性,对水化煤样进行不同风干时间的实验煤样预处理,形成不同风干时间的水化煤样。通过煤样含水率测试、物理吸附实验和程序升温实验,对不同饱和-风干时间的水化煤样以及原煤样的吸氧量和CO,CO2,CH4,C2H4,C2H6,C3H8气体浓度随煤温的变化规律进行实验研究。研究结果表明:不同风干时间水化煤样随着煤温的逐渐升高,吸氧量呈先减小后增大趋势;不同风干时间的水化煤样的自燃标志性气体析出速率随煤温的升高均呈指数增大的变化趋势;在低温氧化阶段,水化煤样比原煤反应时间提前,且反应速率更快,这表明水化煤样比原煤样更加容易发生自燃,且风干时间为20min的水化煤危险性更大。

In order to grasp the spontaneous combustion characteristics of coal samples under different air drying time during the saturation-air drying process of hydrated coal,the pretreatment of experimental coal sample under different air drying time was carried out on the hydrated coal samples to form the hydrated coal samples with different air drying time.Through the testing on the moisture content of coal samples,the physical adsorption experiment and the programmed temperature experiment,the change laws of oxygen uptake and gas concentrations of CO,CO 2,CH 4,C 2H 4,C 2H 6 and C 3H 8 with the coal temperature for the hydrated coal samples and raw coal sample under different saturation-air drying time were studied.The results showed that for the hydrated coal samples with different air drying time,the oxygen uptake decreased first and then increased with the increase of coal temperature,while all the evolution rates of representative gases for the spontaneous combustion presented the exponential increase with the increase of coal temperature.In the period of low temperature oxidation,the reaction time of hydrated coal was earlier than that of raw coal,and the reaction rate was quicker,which showed that the hydrated coal was more prone to the spontaneous combustion than the raw coal sample,and the risk of hydrated coal with the air drying time of 20 min was greater.