煤升温氧化动力学阶段性规律

发布时间：2018-05-14 06:14

本文选题：煤自燃 + 热分析实验　；参考：《西安科技大学学报》2017年04期

【摘要】：为了研究煤的自燃特性,选取石圪台煤矿22203采煤工作面煤样为研究对象,采用热分析技术,对煤氧化升温过程中质量及动力学参数变化规律进行了探讨。结果表明:煤的失重呈阶段性变化规律,可分为低温失重、吸氧增重、缓慢化学反应和燃烧阶段;通过采用改进的KAS法计算煤升温氧化动力学参数,可知在温度达到燃点前,随着温度升高反应活化能增加,说明不断有难燃结构参与到反应。超过燃点温度,在燃烧阶段初期,活化能基本保持不变,而指前因子出现峰值,表明有大量活性结构被激活,准备参与到燃烧反应中。在燃烧阶段中后期,活化能随温度的增加逐步减小,表明该阶段有芳香环的破坏形成更易于反应的活性结构;动力学参数的补偿效应存在显著分段性,说明在煤氧反应过程中前后反应不同,其整体反应存在不止一个反应机理。研究结果对防治煤自燃提供理论依据。
[Abstract]:In order to study the spontaneous combustion characteristics of coal, the coal sample of 22203 coal face in Shigetai Coal Mine was selected as the research object, and the variation law of quality and dynamic parameters in the process of coal oxidation and heating was discussed by means of thermal analysis technology. The results show that the weight loss of coal varies in stages, which can be divided into low temperature weight loss, oxygen absorption, slow chemical reaction and combustion stage, and the modified KAS method is used to calculate the kinetic parameters of coal heating and oxidation, which shows that before the temperature reaches the ignition point, The activation energy of the reaction increases with the increase of temperature, which indicates that the refractory structure is continuously involved in the reaction. Above the ignition temperature, the activation energy remained basically unchanged at the beginning of the combustion stage, while the peak value of the pre-exponential factor showed that a large number of active structures were activated and were ready to participate in the combustion reaction. In the middle and late stage of combustion, the activation energy decreases gradually with the increase of temperature, which indicates that the destruction of aromatic rings in this stage leads to a more reactive active structure, and the compensatory effect of kinetic parameters is significantly piecewise. The results show that there is more than one reaction mechanism before and after coal oxygen reaction. The results provide theoretical basis for preventing coal spontaneous combustion.
【作者单位】：西安科技大学安全科学与工程学院;教育部西部矿井开采及灾害防治重点实验室;
【基金】：国家自然科学基金(U1361129)
【分类号】：TD752.2

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