摘要
在热重分析仪、固定床和流化床实验台上对油页岩和半焦的着火特性进行了实验研究。在固定床和流化床实验中,根据排放气体(CO,CO_2)和床温的变化曲线判断着火温度,结果表明:随着粒径的增大,油页岩和半焦的热重着火温度和流化床一次投料着火温度逐渐增大;固定床实验测得的着火温度比其他技术低,对于流化床一次投料实验,半焦的着火温度在很大程度上取决于投料温度,不同的实验技术对着火机理有很大影响,油页岩固定床实验和流化床间断给料实验为均相着火,流化床一次给料实验油页岩着火机理逐渐向非均相着火过渡;利用热爆炸理论对不同实验条件导致的着火温度不同进行了理论分析,当无量纲换热系数ψ从0.4167变化到2.0时,无量纲着火温度θg从0.0599变化到0.06732。
Ignition characteristics of oil shale and semi-coke were performed using thermogravimetric analyer （TGA）, fixed bed and fluidized bed experimental techniques. In the fixed bed and fluidized bed experiment, the ignition temperature was evaluated from gas evolution （CO,CO2） and bed temperature ＇profiles. The results show that with the increasing of particle size of oil shale and semi-coke, ignition temperature increase from TGA experiment and fluidized bed experiment with once feed. There is a lower ignition temperature for fixed bed experiment than others. For fluidized bed experiment with once feed, ignition temperature of semi-coke significantly depends on feed temperature. Changes of experimental techniques related to different experimental conditions have strong effects on ignition mechanism. Exhaust gas from oil shale fixed bed experiment and fluidized bed experiment with pulse feed indicated a homogeneous ignition mechanism. Oil shale ignition mechanism from fluidized bed experiment with once feed may shift from homogeneous to heterogeneous one. The interpretation of the variation of ignition temperatures from different techniques has been obtained in terms of thermal explosion theory （TET）. It can be seen that the dimensionless heat transfer coefficient ψ from 0.4167 to 2.0 can account for a variance in the dimensionless ignition temperature θg in the range of 0.059 9-0.067 32.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2008年第26期59-64,共6页
Proceedings of the CSEE
基金
科技部"十一五"重点科技攻关项目(2004BA907A24)~~
关键词
油页岩
半焦
热重分析
固定床实验
流化床实验
着火
oil Shale
semi-coke
thermogravimetric analysis
fixed bed experiment
fluidized bed experiment
ignition
