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为了研究煤在低温阶段的自燃活化能及气体产生规律,基于耗氧量与煤温间的计算模型,利用煤氧化动力学测试系统,分析了3种不同自燃性煤的低温氧化表征。结果表明:1)随着煤自燃倾向性增强,煤的耗氧量和耗氧速率逐渐增大,且其耗氧速率急剧增大的拐点温度逐渐升高;2)不同自燃性煤活化能变化规律存在显著差异,利用阶段耗氧量拐点计算出铜川和大同煤样温度分别为203℃、228℃时,活化能快速减小,开始进入自发氧化阶段;晋城煤样活化能经历先减小后增大的过程,其中过渡温度段91~135℃时,活化能最小;同时拟合出活化能(E)与指前因子(A)关系式满足动力补偿效应,验证了机理函数的合理性;3)依据复合气体CO_2/CO、CH_4/C_2H_6、C_2H_4/C_2H_6、C_3H_8/C_2H_6随温度的变化趋势,结合煤低温氧化特性,可预测煤样的氧化进程和煤体温度。
In order to study the spontaneous combustion activation energy and gas generation law of coal at low temperature, based on the calculation model of oxygen consumption and coal temperature, the low temperature oxidation characterization of three different spontaneous combustion coal was analyzed by using coal oxidation kinetics test system. The results show that: 1) With the increase of spontaneous combustion tendency of coal, the oxygen consumption rate and oxygen consumption rate of coal gradually increase, and the temperature at inflection point of oxygen consumption rate increases sharply; 2) The results showed that there was a significant difference between the two samples. The temperature of Tongchuan and Datong coal samples were calculated to be 203 ℃ and 228 ℃, respectively. The activation energy rapidly decreased and began to enter the spontaneous oxidation stage. , The activation energy is the smallest at the transition temperature range of 91-135 ℃. The relationship between the activation energy (E) and the pre-exponential factor (A) is fitted to the dynamic compensation effect to verify the rationality of the mechanism function. 3) Based on the change trend of CO_2 / CO, CH_4 / C_2H_6, C_2H_4 / C_2H_6, C_3H_8 / C_2H_6 of composite gas with the change of temperature, combined with the low temperature oxidation characteristics of coal, the oxidation process and temperature of coal can be predicted.