摘要
为了探究贫煤煤样的氧化燃烧热效应及热动力学行为,分别采用C80微量热系统和热重实验装置对样品进行测试;分析了贫煤煤样在低温氧化及氧化燃烧过程中的热效应,同时也研究了升温速率对贫煤燃烧过程的影响,最后对煤样燃烧过程中的表观活化能和最概然机理函数进行了分析。结果表明:贫煤的低温氧化过程可划分为缓慢氧化阶段、加速氧化阶段和快速氧化阶段;随着升温速率的升高,煤样的TG/DTG曲线向高温区域移动,DTG曲线峰值升高,燃点温度升高;煤粉在热解燃烧阶段的表观活化能随转化率的增加呈现出先升高后下降的趋势,在转化率为0.2时表观活化能达到最大值,为32.4 kJ/mol;升温速率对反应最概然机理函数影响较小,4种升温速率下的反应最概然机理函数均符合A-E方程随机成核和随后生长模型,且函数曲线峰值随升温速率的升高而增大。
To investigate the oxidation combustion heat effect and thermokinetic behavior of lean coal,the pulverized coal samples were tested using C80 micro caloric system and thermogravimetric experimental device,respectively.The thermal effects of lean coal samples during the low-temperature oxidation and oxidation combustion were analyzed,and the influence of the heating rate on the combustion process of lean coal was also studied.In addition,the apparent activation energy and the most probable mechanism function of the coal sample during the combustion process were analyzed.The results indicated that the low-temperature oxidation process of lean coal pulverized coal could be divided into slow oxidation,accelerated oxidation and fast oxidation stages.Moreover,the five characteristic temperature points during the oxidation combustion of pulverized coal were determined by the variations of TG/DTG curves;with the increase of the heating rate,the TG and DTG curves of the coal sample shifted to the high temperature zone,and the peak value of the DTG curve increased with the ignition temperature increased;the apparent activation energy of coal sample in the pyrolysis combustion stage described a trend of first increasing and then decreasing with the increase in the conversion rate.The maximum apparent activation energy were observed when the conversion rate is 0.2,which was 32.4 kJ/mol;heating rates had tiny effect on the most probable mechanism function of the oxidation reaction.The most probable mechanism functions of the reaction under the four heating rates were all basically in line with the AE equation random nucleation and subsequent growth model,and the peak value of the function curve increased with the heating rate increased.
作者
邓军
刘乐
王彩萍
任立峰
白祖锦
DENG Jun;LIU Le;WANG Caiping;REN Lifeng;BAI Zujin(College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Key Laboratory of Western Mine and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China;College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)
出处
《煤矿安全》
CAS
北大核心
2021年第12期35-41,共7页
Safety in Coal Mines
基金
国家自然科学基金资助项目(51974234)
国家重点研发计划资助项目(2018-YFC-0807900)。
关键词
热重实验
低温氧化
特征温度
表观活化能
最概然机理函数
煤自燃
thermogravimetric experiment
low-temperature oxidation
characteristic temperature
apparent activation energy
most probable mechanism function
coal spontaneous combustion
