基于复合指标气体法的水浸清洁煤体自燃预警预报研究

Early Warning and Prediction of Spontaneous Combustion for Clean Coal by Water Immersion Based on Composite Index Gas Method

为了研究浸水程度对清洁煤的预警指标气体的影响规律,选取2种常见清洁煤样分别进行4种程度的浸水预处理,利用煤自燃程序升温实验装置对煤样进行氧化升温试验,并对煤样不同温度阶段升温过程产生的气体进行分析。结果表明:煤样的临界温度为70℃~80℃和干裂温度为120℃~130℃;清洁煤仓首选的煤自燃指标气体为CO,C_(2)H_(6)和C_(2)H_(4)气体。清洁煤煤仓不同含水率煤体的氧化具有分阶段特性,将其划分为3个预测阶段,当φ(CO)/φ(CO_(2))≤0.1时,煤仓的煤体处于物理吸附和局部化学吸附的蓄热阶段,温度为30℃~100℃;当温度为100℃~140℃(自热氧化阶段)时,0.1≤φ(C_(2)H_(4))/φ(C_(2)H_(6))≤0.6;当煤体处于加速氧化阶段140℃~180℃时,φ(O_(2))/(φ(CO_(2))-φ(CO))≤10.61。结合清洁煤煤仓实际情况,及时对参数指标进行修正,完善煤自燃预测预报指标,可有效预防煤自燃灾害事故的发生。

To investigate the pattern of influence of the degree of leaching on the early warning indicator gases of clean coal,two common clean coal samples were selected and pretreated with four degrees of immersion,and the coal samples were subjected to oxidation warming tests using a coal spontaneous combustion procedure warming experimental apparatus,and the gases produced during the warming process at different temperature stages of the coal samples were analyzed.The results showed that the critical temperatures of the coal samples were 70℃to 80℃and the dry cracking temperatures were 120℃to 130℃.The preferred indicator gases for spontaneous coal combustion in clean coal silos are CO,C_(2)H_(6)and C_(2)H_(4)gases.The oxidation of coal bodies with different moisture content in clean coal bunkers has a phased characteristic,which is divided into three prediction stages.Whenφ(CO)/φ(CO_(2))≤0.1,the coal body of the bunker is in the heat storage stage of physical adsorption and local chemical adsorption at 30°C-100°C.When the temperature is 100°C-140°C (self-heating oxidation stage),0.1≤φ(C_(2)H_(4))/φ(C_(2)H_(6))≤0.6.When the coal body is in the accelerated oxidation stage of 140°C-180°C,φ(O_(2))(φ(CO_(2))-φ(CO))≤10.61.Combined with the actual situation of clean coal bunkers,timely correction of parameter indicators and improvement of coal spontaneous combustion prediction and forecasting indicators can effectively prevent the occurrence of coal spontaneous combustion disaster accidents.