低流量煤粉稳燃燃烧器的研究与应用

结合煤粉工业锅炉煤粉流量低和炉膛容积小的特点,运用内二次旋转风、锥形钝体和有限预燃室空间相结合的稳燃技术,开发出一种低流量煤粉稳燃燃烧器。运用CFD技术研究了一次风速、内二次风速、内二次风旋流强度和钝体阻塞率等参量变化对回流区大小和回流速度的影响。提高内二次风速,回流区长度和平均回流速度皆呈现缓慢增加趋势;增加内二次风旋流强度,回流区长度和平均回流速度能较快增加,能明显提高回流区卷吸高温烟气热量;钝体阻塞率为1.070是比较合适的。该燃烧器应用到蒸发量4 t/h煤粉工业锅炉上,能够稳定燃烧,提高锅炉热效率10%～18%。

Study and application of low flow mass pulverizd coal steady burner

The defects of pulverized-coal industrial boiler are low flow and small stove volume.In order to remedy the defects,a new kind of low flow mass pulverized coal steady burner has been explored which utilizes steady combustion technology,including inner twice rotating wind,cone-shape bluff-body as well as limited space of preburning.The influences of velocity of primary wind,velocity of inner twice wind,whirl intensity of inner twice wind as well as block rate of bluff-body on dimensions of backflow area and velocity of backflow have been studied using CFD technology.By increasing the velocity of inner twice wind,the length of backflow area and the average velocity of backflow both increase slowly.On the other hand,both of them increase rapidly while improving the whirl intensity of inner twice wind.This obviously improves heat of high temperature smoke which was rolled up in the backflow area.It would be more appropriate that the block rate of bluff-body is 1.070.Applied to a 4 t/h plverizd-coal industrial boiler,this burner has improved thermodynamics efficiency of boiler by 10% ~18%.