O_2/CO_2气氛下煤粉燃烧热重分析及动力学特性  

Thermogravimetry analysis and kinetic characteristics of pulverized coal in O_2/CO_2 atmosphere

作　　者：唐强[1] 王丽朋[1] 李建雄[1] 黎柴佐[1] 张晓琴[1] 侯世峰[1] 

机构地区：[1]重庆大学动力工程学院,重庆400030

出　　处：《重庆大学学报（自然科学版）》2009年第12期1440-1445,共6页Journal of Chongqing University

基　　金：重庆市科技攻关项目(CSTC2008AC2051)

摘　　要：在综合热分析仪上进行了3种煤粉在O2/N2及O2/CO2气氛下的非等温燃烧试验,研究了不同气氛下煤粉燃烧特性参数的变化,并计算出各工况下的动力学参数。结果表明:在相同O2浓度下,煤粉在O2/N2和O2/CO2气氛下燃烧特性有所不同,用CO2代替N2后煤粉着火温度和燃尽温度均升高,燃烧时间延长,综合燃烧特性指数下降;O2/CO2气氛下,增加O2浓度后,燃烧热重曲线向低温区域移动,着火提前,燃尽温度降低,燃烧时间缩短,综合燃烧指数明显提高,燃烧性能得到改善;煤粉燃烧反应低温段的活化能和频率因子较高温段低,反应级数较小;不同工况下,煤粉2个阶段的反应活化能和频率因子之间存在动力学补偿效应。This study conducts non-isothermal combustion experiments of three types of pulverized coal by Synthesized Thermogravimetry Analyzer in O2/N2 and O2/CO2 atmospheres. It analyzes the changes of combustion characteristic parameters of pulverized coals in different atmospheres and calculated the kinetic parameters at each condition. The results show that combustion characteristics under O2/CO2 atmosphere are different from those under O2/N2 atmosphere at the same O2 concentration. When N2 is replaced by CO2,both ignition time and burnout time of pulverized coals increase,burnout temperature is higher,and combustion characteristic index declines. DTG curves of coal combustion move to low temperature zones when O2 concentration in O2/CO2 mixture increases. It indicates that both ignition and burnout temperature are lower,burnout time decreases,combustion characteristic index obviously increases,and combustion performance of pulverized coals are improved. Activation energy,frequency factor and reaction order at low-temperature stage are lower than those at high-temperature stage. Kinetic compensation relationship exists between combustion activation energy and frequency factor in different atmospheres.

关 键 词：O2/CO2 热重分析 燃烧性能 活化能 补偿效应 

分 类 号：TQ534[化学工程—煤化学工程]