摘要
为研究煤矸石在富氧气氛中的燃烧及动力学特性,利用热重-热差同步热分析仪,分别在空气和10%、21%、30%、40%和50%O2/CO2气氛下对煤矸石进行了燃烧试验。结果表明:21%O2/CO2气氛下较空气气氛下最大失重率更低、最大失重温度更高、放热性能更差;O2/CO2气氛下,随着氧气质量浓度的增大,煤矸石的着火温度、最大失重温度、燃尽温度和热流(DSC)最大放热温度均有所降低,最大失重率、最大放热量、转化速度和综合燃烧指数均有所提高,总放热量呈现出先升高后降低的趋势,在30%氧气质量浓度时达到最大值。煤矸石燃烧过程动力学分析表明,煤矸石在不同氧气质量浓度下均符合二级动力学模型,且随着氧气质量浓度的增大,煤矸石的表观活化能和频率因子均呈现出先增大后减小的趋势,表观活化能E和频率因子A之间存在补偿效应。
In the paper,in order to study the combustion and dynamic characteristics of coal gangue in O2/CO2 atmosphere,the combustion experiments of coal gangue were carried out under the combustion atmosphere of air and 10%,21%,30%,40%and 50%O2/CO2 by TG-DTG synchronous thermal analyzer.The results show that 21%O2/CO2 atmosphere has lower maximum weight loss rate,higher maximum weight loss temperature and poor heat release performance compared to air atmosphere.Under O2/CO2 atmosphere,with the increase of oxygen concentration,the ignition temperature,maximum weight loss temperature,burnout temperature and DSC maximum exothermic temperature of coal gangue are all reduced,and the maximum weight loss rate,maximum heat release rate,conversion rate and comprehensive combustion index are increased.As the oxygen concentration increases,the total exotherm shows a tendency to increase and then decrease,reaching a maximum at 30%oxygen concentration.The kinetic analysis of coal gangue combustion process shows that coal gangue meets the second-order kinetic model under different oxygen concentrations,and with the increase of oxygen concentration,the activation energy and frequency factor of coal gangue increases first and then decreases.There is a compensating effect between the activation energy and the frequency factor.
作者
龚振
宋长忠
贾相如
GONG Zhen;SONG Chang-zhong;JIA Xiang-ru(School of Energy and Power Engineering Institute,Inner Mongolia University of Technology,Hohhot,China,Post Code:010051)
出处
《热能动力工程》
CAS
CSCD
北大核心
2020年第10期94-102,共9页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金(51466010)。
关键词
煤矸石
燃烧特性
氧气质量浓度
热重分析
动力学分析
coal gangue
combustion characteristics
oxygen concentration
thermogravimetric analysis
kinetic analysis
