预氧化煤低温氧化放热和动力学特性研究  

Research on exothermic and kinetic characteristics of low-temperature oxidation of preoxidized coal

作　　者：闫国锋[1] 黄兴利 闫振国 YAN Guofeng;HUANG Xingli;YAN Zhenguo(Shaanxi Huangling Mining Group Co.,Ltd.,Yan'an 727306,China;Shaanxi Huangling No.2 Coal Mine Co.,Ltd.,Yan'an 727306,China;College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi*an 710054,China)

机构地区：[1]陕西黄陵矿业集团有限公司,陕西延安727306 [2]陕西黄陵二号煤矿有限公司,陕西延安727306 [3]西安科技大学安全科学与工程学院,陕西西安710054

出　　处：《工矿自动化》2022年第7期135-141,共7页Journal Of Mine Automation

基　　金：陕西省自然科学基础研究计划项目(S2019-JC-LH-QY-SM-0065)。

摘　　要：现有氧化煤自燃特性研究大多以较低氧化温度和空气条件下制取的煤样为研究对象,缺乏对预氧化煤氧化过程中动力学特性的分析。针对上述问题,利用C80微量热仪以不同氧化温度(100,200,300℃)和氧气体积分数(21%,15%,5%)条件下制取的预氧化煤为对象,研究了其低温氧化反应的放热和动力学特性,并探讨了氧化温度和氧气浓度对预氧化煤低温氧化反应活化能的影响。预氧化煤低温氧化放热特性分析结果:(1)预氧化煤低温氧化进程滞后于原煤样,且滞后程度随氧化温度和氧气浓度升高而增大。(2)预氧化煤低温氧化反应的放热量低于原煤样,且放热量随氧化温度和氧气浓度升高逐渐降低。当氧化温度为100℃时,不同氧气浓度预氧化煤的t1(热流>0时对应的温度)、t2(热流增长率最大值对应的温度)及低温氧化过程的反应热基本相等。(3)随着氧化温度升高,氧气浓度对t1、t2及低温氧化过程的反应热的影响才逐渐明显。表明氧气浓度对预氧化煤低温氧化反应的影响在较高的氧化温度下才体现。但是,太高的氧化温度导致预氧化煤低温氧化反应进程严重滞后且反应放热量<0。预氧化煤低温氧化动力学参数分析结果:(1)预氧化煤低温氧化反应加速氧化阶段的活化能高于原煤样,快速氧化阶段的活化能低于原煤样。表明预氧化煤氧化反应进入加速氧化阶段的门槛提高,却更容易进入快速氧化阶段。(2)从指前因子数据可看出,预氧化煤低温氧化反应相较于原煤样更为迅速。(3)预氧化煤低温氧化过程的活化能没有随氧化温度和氧气浓度的变化表现出明显的规律性:在加速氧化阶段活化能随氧化温度升高而增大,随氧气浓度升高呈先降低后升高趋势;在快速氧化阶段,当氧化温度为100℃,活化能随氧气浓度升高呈先降低后升高趋势,而氧化温度为200℃时则相反。The existing research on the spontaneous combustion characteristics of oxidized coal is mostly based on the coal samples prepared under the conditions of lower oxidation temperature and air.It lacks the analysis of the kinetic characteristics during the oxidation process of oxidized coal.In order to solve the above problems,the C80 microcalorimeter is used to study the exothermic and kinetic characteristics of low-temperature oxidation reaction of preoxidized coal prepared under different oxidation temperatures(100,200,300℃)and oxygen volume fraction(21%,15%,5%).The effects of oxidation temperature and oxygen concentration on the activation energy of low-temperature oxidation reaction of preoxidized coal are discussed.The analysis results of low-temperature oxidation exothermic characteristics of preoxidized coal are shown as follows.①The low-temperature oxidation process of preoxidized coal lags behind that of raw coal.The degree of lag increases with the increase of oxidation temperature and oxygen concentration.②The heat release of low-temperature oxidation reaction of preoxidized coal is lower than that of raw coal.The heat release gradually decreases with the increase of oxidation temperature and oxygen concentration.When the oxidation temperature is 100℃,t1(the temperature at which the heat flow value starts>0),t2(the temperature corresponding to the maximum growth rate of heat flow value)and the reaction heat of low-temperature oxidation of preoxidized coals with different oxygen concentrations are basically equal.③With the increase of oxidation temperature,the effect of oxygen concentration on t1 t2 and the reaction heat of low-temperature oxidation is gradually obvious.The results show that the effect of oxygen concentration on the low-temperature oxidation reaction of preoxidized coal is only reflected at higher oxidation temperatures.However,too high oxidation temperature will lead to a serious lag of the low-temperature oxidation reaction process of pre-oxidized coal and the reaction heat re

关 键 词：煤自燃 氧化煤 预氧化煤 低温氧化 动力学参数 加速氧化 快速氧化 氧化温度 氧气浓度 活化能 指前因子 

分 类 号：TD713[矿业工程—矿井通风与安全]