燃烧器高温富氧直接点火劣质煤的数值模拟  

Numerical Simulation of Low Quality Pulverized Coal Igniting in High Temperature Oxygen Enriched Air Heating Combustor

作　　者：郑建祥[1] 李时光[1] 朱秀丽[2] 

机构地区：[1]东北电力大学能源与动力工程学院,吉林吉林132012 [2]东北电力大学理学院,吉林吉林132012

出　　处：《锅炉技术》2016年第2期57-62,共6页Boiler Technology

基　　金：吉林市科技发展项目(20156405)

摘　　要：对多级燃烧器的富氧气氛下煤粉直接点火进行了数值模拟,研究了各个边界参数对劣质煤着火特性的影响。结果表明:煤粉燃烧温度随着氧含量的提高升幅较少;随着多级煤粉的增加,燃烧温度先上升后下降;热风风量过小不利于燃烧器安全运行;热风温度升高能缩短煤粉着火距离,拉长燃烧高温区的跨度;随着热风流量升高,燃烧器出口温度先上升后下降,但是对着火距离影响不大;一级煤粉量的大小对煤粉的温度阶跃位置影响不大,而对燃烧温度有较大影响;一次风量过小会使煤粉在点火筒里提前着火,不利于燃烧器安全运行;周界风的增加,会降低燃烧温度。Numerical simulation was carried out to a high temperature oxygen enriched air heating multi-stage free-oil ignition system, and analyze the effect with low quality coal in several boundary conditions. The results show that the temperature of coal combustion increases obviously with the increase of the oxygen content, but not significantly to increase later. With the increase of multi-stage pulverized coal, the combustion temperature would be low after high. High temperature air rate could increase the combustion temperature, but it would harmful to the burner if the rate is too low. High temperature air could shorten the ignition standoff distance, and strech the high temperature combustion area. First stage pulverized coal has little effect to the ignition standoff distance, and clearly affect to the combustion temperature. With the decrease of the first stage air rate, it could shorten the ignition standoff distance, but low air rate is not good for running the burner safely. Increasing the ringed cooling air could lower the temperature of the burner.

关 键 词：富氧燃烧 着火距离 燃烧温度 

分 类 号：TK223.23[动力工程及工程热物理—动力机械及工程]