煤粉热解特性对其富氧气氛下着火机理的影响  

Effect of Pyrolysis Characteristics of Pulverized Coal on the Ignition Mechanism of Oxy-Fuel Combustion

作　　者：雷鸣[1] 王春波[1] 王松岭[1] 阎维平[1] 

机构地区：[1]华北电力大学能源动力与机械工程学院,保定071003

出　　处：《燃烧科学与技术》2012年第3期260-264,共5页Journal of Combustion Science and Technology

基　　金：国家高技术研究发展计划(863计划)资助项目(2009AA05Z310);教育部新世纪优秀人才支持计划资助项目(NCET-08-0770);中央高校基本科研业务费专项资金资助项目(11QX76)

摘　　要：利用非等温热重分析法对两种烟煤的热解特性及富氧下的燃烧特性进行研究.实验结果表明,煤粉中低温下的热解行为对其富氧气氛下的着火机理有明显影响.挥发分初析温度低、热解特性指数D大的煤,随着氧体积分数的增加,着火方式逐渐由非均相转变为均相.而挥发分初析温度高、D较小的煤,着火方式则无明显变化.热解活性高的煤,在着火机理转变后,着火温度显著降低,但燃尽温度基本不受影响.氧体积分数提高后两种煤粉的燃烧特性指数S都有所增大,但相同氧体积分数下不同煤种之间的S相差不多,说明着火机理的改变对S无明显影响.Non-isothermal thermogravimetric experiments were performed to study the pyrolysis characteristics and oxy- fuel combustion characteristics of two kinds of bituminous coal. The results indicate that the pyrolysis characteristics of pulverized coal have significant effects on the mechanism of ignition in oxy-fuel atmosphere. If the coal yields the vola- tiles earlier and has higher pyrolysis index D, the heterogeneous ignition converts to the homogeneous ignition with the oxygen content increasing. But if the coal yields the volatiles later and has lower index D, the mechanism of ignition does not change. After the change of ignition mechanism, the ignition temperature of coal with higher pyrolysis reactivity var- ies greatly, while the burnout temperature is hardly influenced. The combustion index S gradually increases with the rise of oxygen concentration, but at the same oxygen concentration, the indexes of different coals are similar, indicating that the transformation of ignition mechanism has little influence on index S.

关 键 词：富氧燃烧 热解特性 着火机理 热重分析 

分 类 号：TK16[动力工程及工程热物理—热能工程]