摘要
为研究煤颗粒在燃烧过程中的热解与焦燃烧行为,给解耦燃烧装置的设计和优化提供参考,基于煤燃烧过程的不同阶段(干燥阶段、热解阶段、焦燃烧阶段),结合传热传质过程和反应动力学机理,建立了单颗粒煤燃烧模型。利用该模型,分析了煤在燃烧过程中颗粒内部温度、气体组分的演化过程,以及热解阶段和焦燃烧阶段的耦合关系。结果表明,在煤燃烧过程中,靠近颗粒表面处焦的燃烧提高了颗粒内部焦燃烧的初始反应温度,导致颗粒可达到的最高温度出现在颗粒中心处;随着颗粒尺寸的增加,热解时间和总燃烧时间的差值增加,该趋势对于粒径大于4 mm的煤颗粒更加明显,意味着在解耦燃烧实际应用中应选用粒径大于4 mm的煤颗粒。
Considering that the deep understanding of the pyrolysis and char combustion behavior of coal particle during combustion could provide a reference for the optimization design of decoupling combustion device,a single particle coal combustion model was established.The model took into account the different stages of coal combustion process(such as drying stage,pyrolysis stage and char combustion stage),and combined the heat and mass transfer process as well as kinetic mechanism.With the model,the coupling relationship between the pyrolysis stage and char combustion stage and the evolution process of the temperature and gas components inside particle were analyzed.The results showed that:the combustion of char near the particle surface increased the initial reaction temperature inside particle,which caused the maximum temperature for the particle taking place at the particle center.With the increase of particle size,the difference between pyrolysis time and total combustion time increased.This trend was more obvious for coal with particle size>4 mm.It implied that the coal particles>4 mm should be selected for the practical application of decoupling combustion.
作者
于海鹏
Yu Haipeng(China Coal Research Institute Company of Energy Conservation,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China;National Energy Technology and Equipment Laboratory of Coal Utilization and Emission Control,Beijing 100013,China)
出处
《煤化工》
CAS
2021年第4期34-40,共7页
Coal Chemical Industry
关键词
煤燃烧
热解
焦燃烧
单颗粒煤燃烧模型
颗粒尺寸
coal combustion
pyrolysis
char combustion
single coal particle combustion model
particle size
