煤自燃过程温升特性及产生机理的实验研究

Experimental Study on the Temperature Rising Characteristic of Spontaneous Combustion of Coal

为了研究煤在自燃过程中会出现温度上升突然加快所产生的原因,为煤矿现场煤炭自然火灾的防治工作提供理论依据,采用绝热法、程序升温法对北皂褐煤氧化过程中自热升温特性、耗氧、CO,CO2气体产物特性的研究,提出煤的氧化过程具有分阶段性,主要可以分为2个阶段:低温缓慢氧化阶段和高温快速氧化阶段;并采用原位傅里叶红外光谱实时连续地采集了北皂褐煤表面主要活性官能团在氧化过程中的变化规律。实验结果表明:煤的分阶段特性主要是由于OH的反应导致的,OH反应吸热是低温阶段热量难以积聚的主要原因,当OH反应消耗殆尽时,煤中热量迅速积聚,煤温迅速升高。

To find out the reason for the sudden rise of the oxidation temperature in coal spontaneous combustion process, and provide theoretical basis for the prevention and control of spontaneous com-bustion in coal mines, the adiabatic testing method and programmed temperature rising method were used in this paper, to study the temperature rising, oxygen consumption, gas production （CO and CO2） characteristics of lignite in Baizao coal mine during the oxidation process. It is indicated that the oxida-tion of lignite has the subsection characteristic, and can be divided into two stages, that is, slow oxida-tion process during the low temperature and fast oxidation during the high temperature. The functional groups variation law during the whole oxidation process was tested by in-situ FTIR. The results show that the reaction of OH leads to the subsection characteristic of lignite during oxidation process, and the endothermic reaction of OH is the main reason why the heat is difficult to accumulate in the low tem-perature stage. Once OH is depleted, heat begins to accumulate and the temperature of coal rises imme- diately.