CO2气化反应对O2/CO2气氛中煤焦燃烧特性影响 |
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引用本文: | 雷鸣,王春波,黄星智.CO2气化反应对O2/CO2气氛中煤焦燃烧特性影响[J].煤炭学报,2015,40(Z2):511-516. |
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作者姓名: | 雷鸣 王春波 黄星智 |
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作者单位: | 华北电力大学 能源动力与机械工程学院,河北 保定 071003 |
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基金项目: | 中央高校基本科研业务费专项资金资助项目(2014QN41);国家自然科学基金资助项目(51276064) |
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摘 要: | 为探讨CO2气化反应在低氧气体积分数下对煤焦燃烧及燃烬过程的影响,利用热天平对比研究了大同煤焦在O2/N2/和O2/CO2气氛中的燃烧行为,主要探讨CO2气化反应对煤焦富氧燃烧特性的影响。实验结果表明,在5%氧气体积分数下,煤焦在O2/CO2气氛下的燃烧速率要低于O2/N2气氛下。当氧气体积分数降低到2%,且温度高于900 ℃时,在CO2气化反应的作用下,煤焦在O2/CO2气氛中的整体反应速率逐渐高于O2/N2气氛中的燃烧速率,使得燃烬提前。随着环境温度的升高,煤焦在O2/CO2和O2/N2气氛下的反应速率均有所增加,但在O2/CO2中增幅更显著。动力学分析显示,在5%氧气体积分数时,大同煤焦在O2/N2中的活化能要低于O2/CO2中。当氧体积分数减少到2%时,由于高温下煤焦的燃烧和气化反应同时进行,较高的气化反应活化能使得煤焦在O2/CO2中的整体反应活化能有明显增加。
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关 键 词: | 富氧燃烧 CO2气化 煤焦 燃烧特性 活化能 |
收稿时间: | 2015-05-07 |
Effect of CO2 gasification on the combusiton characteristics of char under O2/CO2 atmosphere |
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Abstract: | In order to investigate the effect of CO2 gasification reaction of coal char combustion and combustion process under low oxygen concentration,the burning behaviors of Datong char under O2/N2 and O2/CO2 atmosphere were comparatively investigated by thermo-gravimetric analyzer,in particular,the influence of CO2 gasification to the oxy-fuel combustion characteristics of char were mainly studied.The results generally indicate that at 5% oxygen concentration the burning rate of char is slower in O2/CO2 than in O2/N2 mixture.When the oxygen concentration reduces to 2% and the temperature is above 900 ℃,the overall reaction rate of char in O2/CO2 is higher than the burning rate of char in O2/N2 mixture,which results in an earlier burnout.With the rise in temperature,the both burning rates of char under O2/CO2 and O2/N2 atmosphere increase,but the growth amplitude in O2/CO2 mixture is more significant.The kinetic analysis shows that at 5% oxygen concentration the activation energy in O2/N2 is lower than in O2/CO2 mixture.As the combustion and gasification of char occur simultaneously at high temperature with 2% oxygen concentration,the overall reaction activation energy under O2/CO2 atmosphere increases obviously due to the higher activation energy of CO2 gasification. |
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Keywords: | oxy-fuel combustion CO2 gasification char combustion characteristic activation energy |
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