State Key Laboratory for the Coal Mine Disaster Dynamics and Controls,Chongqing University,Chongqing　 400030,China

煤自燃是煤矿开采过程中诱发瓦斯爆炸灾难的主要安全隐患之一,为了研究煤自燃高温区域的动态变化规律,利用煤自然发火实验炉模拟了煤样从常温至着火点的全过程,全面分析了煤自然发火过程中高温区域、指标气体的时空变化规律,得出:1在煤自燃过程中,高温点首先出现在低氧浓度分布区,逐步向高氧浓度分布区偏移,即高温点由离进气孔较远的上部逐渐向下部进气孔位置移动。低温阶段,高温点下移缓慢;高温阶段,高温点快速下移。煤体高温点最终停留在约为煤堆高度的3/10处;2实验中炉内各个区域温度变化差异较大,相应区域指标气体生成速率也随之不同。实验确定了煤自氧化加速点(130℃),当煤体温度达到大约130℃时,高温点所处的高度大约为127 cm(煤堆高度的6/10处),各项指标气体的生成速率v急剧增大,127 cm可作为指标气体生成速率的分界线。分界线之上,v缓慢增大,指标气体产量占总量的比例极小;分界线之下,v急剧增大,指标气体产量所占总量的比例极大。

Spontaneous combustion of coal is one of main mine hazards which may result in gas explosion disaster in coal mining operation. In order to study the dynamic variation of the high temperature region of coal spontaneous com- bustion,this paper used a laboratory furnace to simulate the whole process of coal spontaneous combustion from room temperature to the ignition point of coal samples,and analyzed the dynamic rules of the temperature region and index gases comprehensively. The study obtained the following conclusions:in the process of spontaneous combustion of coal,(1) hot spots firstly appeared in the area with low oxygen concentration,and gradually shifted to the area with high ox- ygen concentration,namely hot spots gradually moved from the upper far away from air intake to air intake. At the cry- ogenic stage,hot spots moved down slowly,while,in high-temperature phase,hot spots moved down quickly. Finally hot spots remained in about 3 / 10 height of coal pile;and (2) in the laboratory furnace,the temperatures of various regions are different,so at the same time,the generation rate of index gas showed big differences at different heights. The self- activation reaction stage (130 ℃ ) was determined experimentally. When the temperature reached about 130 ℃ ,hot spots were located at approximately 127 cm (about 6 / 10 height of the coal pile),the generation rates v of all kinds of index gases increased sharply,so 127 cm could be used for the dividing line of generation rates. Above the dividing line,v increased slowly,the production of index gas accounted for a very small proportion of the total;under the divid- ing line,v increased rapidly,the production of index gas accounted for a very large proportion of the total.

国家自然科学基金青年基金资助项目(51204216)；博士点基金-优先发展领域资助项目(20130191130003)；国家科技支撑计划资助项目(2012BAK04B09)；

Li Lin,Chen Junchao,Jiang Deyi,et al. Experimental study on temporal variation of high temperature region and index gas of coal sponta- neous combustion[J]. Journal of China Coal Society,2016,41(2):444-450.