摘要
为有效防治红庆河矿煤层自然发火灾害,利用同步热分析仪测试了该矿不粘煤在4种不同升温速率(5,10,15,20 K/min)下样品质量随温度的变换规律,采用atava推断法和Popescu法对数据进行了动力学分析。结果表明相同温度下,升温速率越小,煤的反应程度越高;确定了红庆河煤自燃升温过程中8个特征温度点及其阈值。据此将自燃升温过程划分为5个阶段:水分蒸发及气体脱附、吸氧增重、热分解失重、燃烧阶段和燃尽阶段。研究发现第Ⅰ阶段的最概然机理函数符合二维扩散Jander方程,明确了该阶段氧化动力学模式。进而计算出4种不同升温速率下的活化能分别为:64.35,110.91,70.42,59.72 kJ/mol,指前因子分别为3.51×1014,1.29×1021,3.41×1015,1.23×1014 s-1.活化能和指前因子动力学计算结果揭示了不同升温速率条件下,第Ⅰ阶段煤氧复合反应的程度不同,这为研究煤自燃分级预警方法和主动防控技术提供了重要的理论依据。
In order to effectively prevent and control the mine spontaneous combustion disaster of Hongqinghe coal mine,the dynamic characteristics of the coal spontaneous combustion were examined.Simultaneous thermal analysis technology was used to test the change of sample quality with temperature at four different heating rates(5,10,15,20 K/min)of non-stick coal of Hongqinghe Mine.The atava inference method and the Popescu method were used to calculate the kinetics.The results show that at the same temperature,the smaller the heating rate,the higher the degree of coal reaction.Eight characteristic temperature points during the spontaneous combustion temperature rise of Hongqinghe coal were identified with characteristic temperature thresholds given.Therefore,the process of coal spontaneous combustion heating was divided into five stages:water evaporation and gas desorption,oxygen absorption weight gain,thermal decomposition weight loss,combustion stage and burnout stage.It is found that the most probable mechanism function of the low-temperature oxidation stage of the Hongqinghe coal mine conforms to the two-dimensional diffusion Jander equation,and the oxidation kinetic model at this stage was determined.The activation energy at four different heating rates were calculated to be 64.35,110.91,70.42,59.72 kJ/mol.The pre-finger factors are 3.51×1014,1.29×1021,3.41×1015,and 1.23×1014 s-1,respectively.The activation energy and pre-finger factor kinetic calculation results reveal that the energy barrier of the first stage coal-oxygen composite reaction is different under different heating rate conditions,this provides theoretical and practical significance for the study of coal spontaneous combustion classification early warning method and active prevention and control technology.
作者
张铎
唐瑞
王振
邓军
张辛亥
蒋志刚
陈曦
ZHANG Duo;TANG Rui;WANG Zhen;DENG Jun;ZHANG Xin-hai;JIANG Zhi-gang;CHEN Xi(College of Safety Science and Engineering,Xi’ an University of Science and Technology,Xi’ an 710054,China;Postdoctoral Research Mobile Station in Mining Engineering,Xi’ an University of Science and Technology,Xi’ an 710054,China;Xi’ an Railway Engineering Staff University,Xi’ an 710065,China;Technology Center,Sichuan Coal Industry Group Limited Company,Chengdu 610091,China)
出处
《西安科技大学学报》
CAS
北大核心
2020年第6期974-980,共7页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(51904234,51974240)。
关键词
煤自燃
热分析
动力学
活化能
指前因子
特征温度
coal spontaneous combustion
thermogravimetric analysis
thermodynamics
activation energy
preexponential factor
characteristic temperature
