陕北侏罗纪煤田浅埋近距离煤层煤自燃预测预报体系研究

Study on Coal Spontaneous Combustion Prediction System of Shallow Buried Close Distance Coal Seam in Jurassic Coalfield of Northern Shaanxi

为了更好地掌握浅埋近距离煤层煤样的自然发火在不同阶段所显现的特征,并以此为根据及时采取相关措施加以防范,运用程序升温系统测试了2种不同煤层煤样的耗氧速率,结合CO浓度确定了临界温度点。对不同氧化阶段的气体产物进行了研究,并从诸多气体产物中选取了指标气体,结合多参数指标方法,最终建立了多煤层煤自燃预测预报体系。研究结果表明,这2种方法均可计算临界温度和干裂温度,其中2种煤样的临界温度为70℃~80℃,干裂温度为110℃~120℃。在氧化初期耗氧速率和Graham指数变化较小。预测两煤层煤自燃的主要指标为φ(C_(2)H_(4))/φ(CH_(4));φ(CO),φ(C_(2)H_(4)),φ(CO)/φ(CO_(2)),Graham指数,耗氧速率可作为辅助气体指标。由此建立的煤自燃预测预报体系可以精准地判断煤层自燃所处阶段,为多煤层煤自燃预报及救灾提供参考。

In order to better grasp the characteristics of the spontaneous ignition of the coal samples in shallow buried and short distance coal seams at different stages,and take relevant measures to prevent them in time based on this,the oxygen consumption of two different coal seam coal samples was tested by using the programmed heating system.The rate,combined with the CO concentration,determined the critical temperature point.The gas products in different oxidation stages were studied,and the indicator gas was selected from many gas products,combined with the multi-parameter indicator method,and finally a multi-coal seam coal spontaneous combustion prediction and prediction system was established.The research results show that both methods can calculate the critical temperature and dry cracking temperature.The critical temperature of the two coal samples is 70℃~80℃,and the dry cracking temperature is 110℃~120℃.Oxygen consumption rate and Graham index changed less in the early stage of oxidation.The main indicators for predicting the spontaneous combustion of coal in the two coal seams areφ(C_(2)H_(4))/φ(CH_(4)),φ(CO);φ(C_(2)H_(4)),φ(CO)/φ(CO_(2)),Graham index,Oxygen consumption rate can be used as an indicator of auxiliary gas.The coal spontaneous combustion prediction and prediction system established in this way can accurately judge the stage of coal spontaneous combustion,and provide a reference for multi-coal seam coal spontaneous combustion prediction and disaster relief.