摘要
对 116 0t·h-1四角切圆电站锅炉的燃烧过程进行了数值模拟 ,燃烧器组采用常规直流煤粉燃烧器和低NOx煤粉燃烧器两种形式 .结果表明 ,大空间锅炉炉膛的速度场、温度场分布很不均匀 ;燃烧器上部附近的炉膛中心烟气上升速度最小 ,湍动能最大 ,温度最高 .烟气上升速度分布图形 ,在燃烧器区域为单峰形 ,即炉膛中心上升速度最大 ;在燃烧器上部为马鞍形 ,即截面环形区域的上升速度最大 .烟气温度分布图形 ,在燃烧器区域呈马鞍形 ,即中心区域和四周水冷壁附近的温度较低 ,截面环形区域的温度最高 ;在燃烧器上部区域为单峰形 ,即炉膛中心的温度最大 .水冷壁附近烟气温度的最大值 ,即结渣的可能区域位于旋转火焰的下游 .炉膛的切圆直径 ,在燃烧器区域随炉膛高度增大不断减小 ,至燃烧器上部附近急剧增大 ,之后随高度增大成一常数 .电站锅炉的常规直流煤粉燃烧器改造成低NOx 燃烧器时 ,炉膛的速度场、湍动能场、截面切圆直径和旋流强度以及温度场等保持不变 .
Combustion process of 1 160 t·h -1 utility tangentially fired pulverized-coal boiler is simulated with two kinds of burners,one is a conventional burner,and the another is a low NO x burner.The results show that the velocity and temperature distribution of large furnace are not very uniform.At the centre of the section near the top of burners,its rising velocity is minimum,its turbulence kinetic energy is maximum,and its temperature is maximum too.The rising velocity distribution is like a mountain in burner's zone,and the maximum rising velocity is located in the centre of the section,its rising velocity distribution is like a dip between two peaks above the burner's zone,and the maximum rising velocity is in annular zone.The temperature distribution in burner's section shapes a dip between two peaks.The temperature is lower near the water wall and in the center of a section,and its highest temperature is in the annular sector.The temperature distribution is like a mountain above the burner zone,and the maximum temperature is in the centre of the section.There is the maximum temperature of gas near water wall,where the maximum potentiality of sticky slag is down stream of rotational flame.The diameter of tangential circle is reduced along height increasing in burner's zone.It's increased fast near the top of the burner's zone,then it's constant along the height.Everything is nearly the same about the velocity,turbulence kinetic energy,the tangential circle diameter,the vortex and the temperature when conventional burner is displaced with low NO x burner.
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第8期1042-1045,共4页
Journal of Tongji University:Natural Science
关键词
电站锅炉
燃烧特性
速度
湍动能
旋流强度
切圆直径
温度
数值模拟
utility boiler
combustion characteristic
velocity
turbulence kinetic energy
vortex
tangential circle diameter
temperature
numerical simulation
