摘要
针对某电厂锅炉由于燃用煤质下降而导致其在实际运行过程中出现燃烧不稳定及炉渣含碳量过高等问题,通过对实际燃用煤种以及炉内燃烧情况进行分析,提出改造燃烧器系统以提高炉内稳燃能力、降低炉渣含碳量,并对改造前后炉膛内的燃烧情况进行了数值模拟.结果表明:改造后的炉膛内,下两层一次风的集中布置,使得主燃区内温度升高,有效保证了煤粉初期的着火和燃烧;下两层二次风的集中布置,提高了二次风对一次风煤粉气流的撑托作用,使下一次风内煤粉颗粒掉入冷灰斗内数量减少,下二次风的推迟送入也保证了煤粉后期的稳定燃烧;炉内燃烧稳定性提高,炉渣含碳量降低.
To solve the problems of unstable combustion and high carbon content in slag of a utility boiler burning poor coal,a retrofit scheme is proposed for the burner system based on analysis of the coal quality and the combustion condition,after which a numerical simulation is carried out to the combustion condition before and after retrofit.Results show that concentrating two layers of lower primary air can improve the temperature in primary combustion zone,resulting in sufficient ignition and combustion of coal in the initial stage;while concentrating two layers of lower secondary air can enhance the supporting action of secondary air to the flow of pulverized coal carried by primary air,resulting in less quantity of pulverized coal particles dropping into the ash hopper.Putting off the supply of secondary air in lower layers is beneficial to coal combustion in later periods.The scheme may help to stabilize the coal combustion and reduce the carbon content in boiler slag.
出处
《动力工程学报》
CAS
CSCD
北大核心
2012年第2期106-111,共6页
Journal of Chinese Society of Power Engineering
关键词
冷灰斗
稳定燃烧
炉渣含碳量
一次风
二次风
ash hopper
stable combustion
carbon content in slag
primary air
secondary air
