硫含量对无烟煤自燃特性影响实验研究

Experimental study on the effect of sulfur content on spontaneous combustion characteristics of anthracite

  • 摘要: 为研究不同硫含量对无烟煤自燃特性的影响,利用管式炉程序升温实验系统对5种不同硫含量(1.02 %、3.07 %、5.14 %、7.13 %和11.98 %)煤样的氧化过程进行了测试与分析,研究了相关气体体积分数随温度的变化规律,定量分析了不同硫含量对煤低温氧化过程中CO、CO2气体释放特性及自燃特征温度的影响规律。通过计算不同硫含量煤样在不同温度条件下的耗氧速率,定量考察了耗氧速率随温度的变化规律。运用化学反应动力学原理计算出不同硫含量条件下煤样的表观活化能,定量分析了表观活化能随硫含量的变化规律。结果表明:当硫含量不变时,CO和CO2气体释放量、耗氧速率随温度的升高均呈指数级增长,表观活化能则逐渐减小。在临界温度之前,CO和CO2气体、耗氧速率以及表观活化能变化幅度较小,在临界温度之后变化幅度较大。随着硫含量的增加,各温度点的CO和CO2气体释放量、耗氧速率呈现出先增加后减少的变化规律,在硫含量为5.14 %处达到最大值。自燃特征温度和表观活化能则呈现出相反的变化规律,在硫含量为5.14 %处达到最小值,此时煤样自燃倾向性最大,即硫含量对无烟煤自燃倾向性影响的临界值约为5.14 %。

     

    Abstract: To study the influence of different sulfur contents on the spontaneous combustion characteristics of anthracite, the oxidation processes of five coal samples with different sulfur contents (1.02%, 3.07%, 5.14%, 7.13% and 11.98%) were tested and analyzed using a tube furnace programmed temperature rise experimental system. The variation laws of the volume fractions of related gases with temperature were investigated, and the influence laws of different sulfur contents on the release characteristics of CO and CO2 gases and the spontaneous combustion characteristic temperatures during the low-temperature oxidation of coal were quantitatively analyzed. By calculating the oxygen consumption rates of coal samples with different sulfur contents under various temperature conditions, the variation pattern of oxygen consumption rate with temperature was quantitatively investigated. Using the principles of chemical reaction kinetics, the apparent activation energy of the coal samples under different sulfur contents was calculated, and the variation pattern of the apparent activation energy with sulfur content was quantitatively analyzed. The results show that when the sulfur content remains constant, the release amounts of CO and CO2 gases and the oxygen consumption rate all increase exponentially with the rise in temperature, while the apparent activation energy gradually decreases. Before the critical temperature, the changes in the release amounts of CO and CO2 gases, the oxygen consumption rate, and the apparent activation energy are relatively small, but after the critical temperature, the changes become significant. As the sulfur content increases, the release amounts of CO and CO2 gases and the oxygen consumption rate at each temperature point show a pattern of first increasing and then decreasing. The maximum values are reached at a sulfur content of 5.14%. The auto-ignition characteristic temperature and apparent activation energy show an opposite pattern of change. They reach their minimum values at a sulfur content of 5.14%, at which point the coal sample has the greatest tendency to self-ignite, indicating that the critical value of sulfur content on the self-ignition tendency of anthracite is approximately 5.14%.

     

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