氧气体积分数对煤自燃特性影响的实验研究

    Experimental study on effect of oxygen volume fraction on spontaneous combustion characteristics of coal

    • 摘要: 为研究氧气体积分数对煤低温氧化自燃的影响,以内蒙古某矿不黏煤为研究对象,利用程序升温实验装置,在氧气体积分数为5%、15%、21%的条件下进行煤低温氧化实验,得到CO、CO2、C2H4气体产生规律;通过计算得到不同氧气体积分数下煤的耗氧速率、气体产生率、放热强度和表观活化能,并分析了3个温度阶段氧气体积分数与活化能之间的关系。结果表明:氧气体积分数越大,CO、CO2、C2H4体积分数越大,且随温度升高呈指数趋势增长;耗氧速率、气体产生率、放热强度变化趋势一致,均随氧气体积分数增大而增大;表观活化能在氧化反应第1、第3阶段随氧气体积分数增大而减小,第2阶段表观活化能随氧气体积分数增大整体呈增大趋势,但氧气体积分数为5%时活化能最大;低温条件下降低氧气体积分数可以抑制煤自燃。

       

      Abstract: In order to study the effect of oxygen volume fraction on the spontaneous combustion of coal oxidation at low temperature, the non-adhering coal from a mine in Inner Mongolia was taken as the research object. The low-temperature oxidation experiments of coal were carried out under the conditions of oxygen volume fraction of 5%, 15% and 21% by temperature-programmed experiment device and the production rules of CO, CO2 and C2H4 gas were obtained. The oxygen consumption rate, gas production rate, heat release intensity and apparent activation energy of coal under different oxygen volume fractions were calculated, and the relationship between oxygen volume fraction and activation energy at three temperature stages was analyzed. The results show that the volume fraction of CO, CO2 and C2H4 increases with the increase of oxygen volume fraction, and increases exponentially with the increase of temperature. The change trend of oxygen consumption rate, gas production rate and heat release intensity is the same, and they all increase with the increase of oxygen volume fraction. The apparent activation energy decreases with the increase of oxygen volume fraction in the first and third stages of oxidation reaction. The apparent activation energy increases with the increase of oxygen volume fraction in the second stage, but the activation energy reaches the maximum when the oxygen volume fraction is 5%. It shows that reducing the volume fraction of oxygen can inhibit coal spontaneous combustion at low temperature.

       

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