综放工作面煤自燃的特征温度点分析及影响规律实验研究

Characteristic temperature point analysis and experimental study on influence law of coal spontaneous combustion in fully mechanized top coal caving face

为了明确兴隆庄煤矿7308综放工作面煤层的自燃特性,指导煤矿采取放灭火措施,对该煤层的煤样进行热重实验,测定该煤层煤样的特征温度点,分析煤样的反应过程。结果表明,临界温度的大小反映了煤样的自燃倾向性高低;在干裂温度下,煤样环状结构中的桥键、烷烃支链及一些小分子结构开始分解,产生小分子气体;达到活性温度后,大分子结构的化学键开始断裂;增速温度点表明能够与氧气反应的活性结构数量增加,化学反应速度明显提高;达到着火温度点后,环状结构全面分解,大量挥发物排出,煤样开始燃烧。通过对比不同粒度、氧浓度和升温速率,煤样的特征点变化呈现一定的规律性。

In order to define the spontaneous combustion characteristics of coal seam in 7308 fully mechanized caving face of Xinglongzhuang Coal Mine and guide the coal mine to take fire extinguishing measures, thermogravimetric test was carried out on the coal sample of the coal seam, the characteristic temperature point of the coal sample was determined, and the reaction process of the coal sample was analyzed. The results show that the critical temperature reflects the spontaneous combustion tendency of coal samples. At the drying temperature, the bridge bond, alkane branch chain and some small molecule structures in the ring structure of coal sample begin to decompose and produce small molecule gas. When the reactivity temperature is reached, the chemical bonds of macromolecular structure begin to break. The increasing temperature point indicates that the number of active structures that can react with oxygen increases and the chemical reaction rate increases obviously. When the ignition temperature is reached, the ring structure is fully decomposed, a large number of volatiles are discharged, and the coal sample begins to burn. By comparing different particle size, oxygen concentration and heating rate, the change of characteristic points of coal samples shows a certain regularity.