CO2效应对煤焦颗粒增氧燃烧影响的数值研究  

Influence of CO_2 Effect on Coal Char Combustion in Oxygen-enriched Environment

作　　者：金旭东[1] 周月桂[1] 金圻烨 郑婷婷[1] 

机构地区：[1]上海交通大学机械与动力工程学院,热能工程研究所,上海200240

出　　处：《动力工程学报》2016年第12期941-944,950,共5页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金资助项目(51276110,51576128)

摘　　要：采用考虑炭粒表面氧化还原反应以及气相CO-O_2反应的连续膜模型,在增氧燃烧中添加一定量的CO_2并采用Ar来调节煤焦颗粒表面温度,分析O_2浓度效应、CO_2化学效应及热效应对煤焦颗粒表面燃烧速率的影响.结果表明:当增氧燃烧系统中O_2体积分数从21%提高到26.5%时,煤焦颗粒表面温度升高154K,燃烧速率增大,且着火时间和燃尽时间均提前;在煤焦颗粒增氧燃烧过程中,O_2浓度效应对煤焦颗粒表面燃烧速率的影响占主导作用,其次是CO_2化学效应,而热效应的影响最低,三者影响的相对贡献率分别为56.4%、25.7%和17.9%.An analysis was conducted to the influence of O2 concentration, CO2 chemical effect and thermal effect on the coal char combustion rate in oxygen-enriched environment containing a certain amount of CO2 with Ar gas to control the surface temperature of the coal char particles, based on a continuous-film model considering the coal char surface C-O2/C-CO2 reactions and the gas phase CO-O2 reaction. Results show that when the volumetric fraction of O2 rises from 21% to 26.5% in the oxygen-enriched environment, the surface temperature of char particles would be increased by 154 K, resulting in increased burning rate, and shortened ignition and burnout time. O2 concentration plays the most important role in influencing the coal char combustion rate, followed by CO2 chemical effect, and then by thermal effect, with relative contributions of 56.4%, 25.7% and 17.9%, respectively.

关 键 词：增氧燃烧 煤焦燃烧 连续膜模型 CO2效应 

分 类 号：TK16[动力工程及工程热物理—热能工程]