不同甲烷气氛下煤自燃指标气体及活化能研究

Research on index gas and activation energy of coal spontaneous combustion under different methane atmosphere

针对不同氧浓度下煤自燃特性的研究大多只考虑不同氧氮比气氛,而对不同甲烷气氛下煤低温氧化规律研究较少的问题,利用程序升温氧化和热重分析实验,对不同甲烷气氛下煤自燃指标气体和活化能进行了研究。结果表明:随着CH4体积分数的增大,产生CO和CO2的初始温度显著升高;在煤氧化初始阶段,不同CH4气氛下CO和CO2生成量均随着温度的升高而缓慢增加;在煤加速氧化阶段,CO和CO2生成量随温度的升高呈指数函数形式增加,且CH4体积分数越低(O2体积分数越高),CO和CO2生成量越大,表明温度越高,CH4对煤氧化的抑制作用越明显;随着CH4体积分数的增大,煤低温氧化活化能增大、指前因子降低,说明CH4体积分数的增大对于煤自燃具有较好的抑制作用。

Most researches on coal spontaneous combustion characteristics under different oxygen concentration only consider different oxygen nitrogen ratio atmosphere,but low temperature oxidation law of coal under different methane atmospheres is seldom studied.In view of the above problems,index gas and activation energy of coal spontaneous combustion under different methane atmospheres were researched by temperature-programmed oxidation experiment and thermogravimetric analysis experiment.The results show that initial temperature of CO and CO2production increase significantly with the increase of methane volume fraction.In initial stage of coal oxidation,production quantity of CO and CO2under different methane atmospheres increase slowly with the increase of temperature.In accelerated oxidation stage of coal,production quantity of CO and CO2increase exponentially with the increase of temperature,and the lower the methane volume fraction(the higher the O2 volume fraction)is,the larger the production quantity of CO and CO2is,indicating that the higher the temperature is,the more obvious the inhibition effect of methane on coal oxidation is.With the increase of methane volume fraction,oxidation activation energy of coal at low temperature increases and index factor decreases,indicating that the increase of methane volume fraction has a good inhibition effect on coal spontaneous combustion.