低流量煤粉稳燃燃烧器内回流特性研究

Study of the Return Flow Characteristics of a Low-flow-rate Pulverized Coal Steady-combustion Burner

运用CFD技术和实验研究了一次风速度、内二次风速度、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。增加内二次风速,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,能明显地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。

By using the CFD technology and test,studied was the influence of such parameter variables as primary air speed,inner secondary air speed,inner secondary air swirling flow intensity and blocking rate of the passivated body etc.on the size of the return flow zone and speed.To increase the secondary air speed,both length of the return flow zone and average return flow speed will assume a slow ascending tendency.To increase the inner secondary air swirling flow intensity,they will increase comparatively quickly,leading to an enhancement of the heat quantity rolled and absorbed in the return flow zone.It is comparatively appropriate when the blocking rate of the passivated body is 1.070.