升温速率和氧浓度对煤表观活化能的影响  

Temperature rising rates and oxygen concentrations influerced to apparent activation energy of coal

作　　者：朱红青[1] 沈静[1] 张亚光[1] 

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083

出　　处：《煤炭科学技术》2015年第11期49-53,106,共6页Coal Science and Technology

基　　金：国家自然科学基金煤炭联合基金资助项目(U12612054)

摘　　要：为了研究升温速率和氧浓度对煤表观活化能的影响,基于同步热分析仪对长治常村矿煤样进行热重试验,在不同升温速率和氧浓度下,找出煤氧反应特征点温度T1—T5,并采用Coats-Redfern积分公式对试验结果进行分析计算,得出相应条件下煤表观活化能。结果表明,在一定范围内,由于煤样升温速率增加,反应速率增加,煤氧反应更容易进行,升温速率为2、5、10、20、30℃/min时的煤表观活化能分别为160.734 6、159.437 6、141.870 1、117.659 7、95.261 8 k J/mol,随升温速率增大而减小,其变化规律基本服从指数函数;另外由于氧浓度增大,煤分子中需要更多被激活的活性基团与氧分子反应,激活这些活性基团需要更多能量,氧体积分数分别为5%、10%、15%、21%、30%时的煤表观活化能分别为85.825 4、111.956 3、127.021 3、141.870 1、155.571 6 k J/mol,随氧浓度增大而增大,其变化规律基本服从对数函数。In order to study the effect of temperature rising rate and the oxygen concentration to apparent activation energy,simultaneous thermal analyzer was applied to thermal gravity experiment of coal samples from Changzhi Changcun Mine. Under different temperature rising rates and oxygen concentrations,feature point temperature T1—T5of coal and oxygen reaction features was found and Coats- Redfern integral formula was applied to analyse and calculation on experiment results and apparent activation energy of coal under relevant conditions was obtained. The results showed that within certain scope,due to temperature rising rate of the coal sample increased,reaction rate would be increased and coal and oxygen reaction would be easily conducted. When temperature rising rates were 2,5,10,20 and 30 ℃ /min,apparent activation energy of coal would be 160. 734 6,159. 437 6,141. 870 1,117. 659 7 and 95. 261 8 k J / mol individually. The apparent activation energy of coal would be reduced with increased temperature rising rate and variation law basically would be subjected to index function. In addition,due to oxygen concentration increased,coal molecules would require more activated active groups to reacted with oxygen molecules. To activate those active groups would require more energy. When oxygen volume fractions were 5%,10%,15%,21% and 30% individually,apparent activation energy of coal would be 85. 825 4,111. 956 3,127. 021 3,141. 870 1 and 155. 571 6 k J /mol individually. With oxygen concentration increased,the apparent activation energy of coal would be increased and the variation law would be subjected to logarithm function.

关 键 词：煤自燃 特征点温度 升温速率 氧浓度 表观活化能 

分 类 号：TD713[矿业工程—矿井通风与安全]