基于分段拟合的煤自燃指标气体优选研究*

为更加精确地得出煤自燃的临界温度并找出煤自燃各个阶段最优的指标气体，以此提高煤层自燃预测预报的准确性，选取西北某矿2号煤和3号煤典型煤样开展程序升温-气相色谱实验，采用分段直线拟合的方法，得出煤自燃过程中的耗氧速率突变点温度和氧化产物生成量激增点温度，在此基础上采用灰色关联度分析法对煤干裂温度之后的指标气体进行优选。结果表明:2号煤和3号煤的自燃临界温度分别为73.0 ℃和72.1 ℃，干裂温度分别为112.6 ℃和109.8 ℃；CO适用于2种煤样全温度下的预测预报；φ(C2H4)/φ(C2H6)和C2H4是2号煤干裂温度之后较优的预测预报指标气体；φ(C2H4)/φ(C2H6),C2H4和C2H6是3号煤干裂温度之后较优的预测预报指标气体。

Research on optimization of index gas for coal spontaneous combustion based on piecewise fitting

In order to obtain the critical temperature of coal spontaneous combustion more accurately and find out the optimal index gas in each stage of coal spontaneous combustion,so as to improve the accuracy of the prediction of coal seam spontaneous combustion,the typical coal samples of No.2 coal and No.3 coal in a Northwest mine were selected to carry out the program heating and gas chromatography experiment,and the method of piecewise linear fitting was applied to obtain the temperature at the mutation point of oxygen consumption rate and the temperature at the surge point of oxidation products amount in the process of coal spontaneous combustion.On this basis,the gray relational analysis method was used to optimize the index gas after the dry cracking temperature of coal.The results showed that the critical temperatures of spontaneous combustion of No.2 coal and No.3 coal were 73.0 ℃ and 72.1 ℃,respectively,and the dry cracking temperatures were 112.6 ℃ and 109.8 ℃,respectively.CO was suitable for the prediction at full temperature of two coal samples.The φ(C2H4)/φ(C2H6) and C2H4 were the better prediction index gases after the dry cracking temperature of No.2 coal,and the φ(C2H4)/φ(C2H6),C2H4 and C2H6 were the better prediction index gases after the dry cracking temperature of No.3 coal.