燃烧器间距和偏转角度对对冲锅炉燃烧特性影响数值模拟
Numerical Simulation Study of Combustion Characteristics of Wall Fired Boiler with Different Burner Arrangements
李朝兵 1赖金平 1王西伦2
作者信息
- 1. 国能南京电力试验研究有限公司,江苏 南京 210023
- 2. 烟台龙源电力技术股份有限公司,山东 烟台 264006
- 折叠
摘要
对某台600 MW对冲锅炉进行燃烧器布置优化,对三层燃烧器采用改变间距和燃烧器角度偏置方案,采用数值模拟方法研究不同方案下锅炉燃烧特性.数值模拟结果表明:墙侧燃烧器向内偏斜5°后,炉内流场发展更充分,对冲效果更强;中上燃烧器上移过高,燃烧器所在高度炉膛横截面高温区不对称现象明显,这不利于炉膛截面热负荷偏差的控制;当采用燃烧器偏置 5°布置后,墙侧燃烧器火焰明显向炉膛内偏斜,向内挤压,使得中间两只燃烧器火焰长度变长,炉内高温区域更加向炉膛中心聚集.不采用燃烧器偏置时,工况2 屏式过热器下部炉膛横向截面上高温区域面积占比最小,采用燃烧器偏置后,高温区面积占比大幅增加,不利于屏式过热器结渣现象的控制,并且NOx排放浓度显著提升.
Abstract
A 600 MW wall fired boiler is modified with burner arrangement,and different distance and angle offsetting schemes are adopted for the three layer burners.Numerical simulation methods are used to study the combustion characteristics of the boiler under different modification schemes.Numerical sim-ulation results show that:after the wall-side burners are skewed inward by 5°,the flow field in the fur-nace develops more fully,and the effect of air shocking is stronger;the middle and upper burners are shifted upward too high,and the asymmetry of high temperature zone in the furnace cross-section at the height of the burners is obvious,which is not conducive to the control of the heat load bias in the hearth cross-section;after adopting burner skewed by 5°,the flames of the wall-side burners are obviously skewed to the hearth,squeezed inward,which makes the middle two The flame length of the middle two burners becomes longer,and the high-temperature region in the furnace gathers more to the center of the furnace.When the burner skewing is not used,the area of the high-temperature region in the trans-verse cross-section of the lower chamber of the screen superheater in Case2 is the smallest,and the area of the high-temperature region increases significantly after the burner skewing is used,which is not con-ducive to the control of the slagging phenomenon of the screen superheater,and the concentration of NOx emission is significantly increased.
关键词
对冲锅炉/燃烧器间距/角度偏置/燃烧/数值模拟Key words
wall fired boiler/burner distance/angle skewing/combustion/numerical simulation引用本文复制引用
出版年
2024
NETL
NSTL
万方数据