【摘要】 为了研究高温贫氧条件对煤自燃指标气体释放的影响,利用西安科技大学自主研发的高温氧化燃烧特性测试装置,测试30～500℃过程中煤自燃气体变化规律,通过使用指标气体的增长率分析法,并参考热分析实验温度区间划分准则,得出5个特征温度点,以此作为划分煤样常温至高温不同氧化阶段的依据,分为4个阶段:分别是临界温度阶段,干裂-活性-增速温度阶段,增速-燃点温度阶段和燃烧阶段。分析不同阶段的指标气体的变化规律,实验结果表明,CO气体在第1阶段增长较为缓慢,在第2,第3阶段增长较为迅速,呈现出指数级增长态势,当温度超过燃烧温度后,CO气体浓度开始呈现出下降的态势,后由于稳定官能团的断裂,气体浓度有所回升。C₂H₄气体在干裂-活性-增速温度阶段前增长较为缓慢,而后急剧增长,当温度到达燃烧温度时,C₂H₄气体浓度达到顶峰,随后随着温度的上升,气体浓度急剧下降。更多还原

【Abstract】 To study the characteristics of high temperature and oxygen-poor conditions on indicator gases of coal spontaneous combustion,the independently designed high-temperature programmed experimental system was used to test the changes of gaseous products during 30 ℃ to 500 ℃. Growth rate analysis method of the indicator gases was adopted to calculate the characteristic temperatures. With reference of thermal gravimetric analysis on temperature division,the five characteristic temperature points are confirmed. Four different oxidation stages were divided by the five temperatures,i. e,as critical temperature stage,crack-active-speedup temperature stage,speedup-ignite temperature stage and combustion stage.Moreover,the variation of indicator gases at different stages were studied. The results showed that the concentration of CO gas increases slowly in the critical temperature stage,and rapidly in the second and third stage with trend of exponential liner. When the temperature exceeded the combustion temperature,the CO gas begins to decrease firstly,and then increase again because of the fracture of the stable functional groups. The C₂H₄ gas released slowly before crack-active-speedup temperature,then increased sharply,and when the temperature reached the combustion temperature,the C₂H₄ gas concentration reached the peak value.更多还原