多级旋流耦合流场值班级雾化性能

Pilot Stage Atomization Performance of Multi-Swirl Coupled Flow Field

多级旋流耦合燃烧技术引进了分区燃烧、贫油燃烧和预混燃烧的概念,具有极大降低NOx排放的潜力,但与常规燃烧室的单纯扩散燃烧模式有较大的差异.耦合流场中,主燃级气流在上游对值班级燃油有进一步的雾化作用,但对燃油的扩散有一定的抑制作用,在下游能够使更大粒径的颗粒回流,并使燃油分布更加均匀;台阶高度越小,上游区域的雾化颗粒平均直径越大,下游区域雾化颗粒平均直径越小;主燃级旋流强度越大,上游区域的燃油颗粒越大;主燃级进出口压降分配对燃油颗粒大小无显著影响.

The multi-swirl coupled combustion technology introducing the concepts of staged combustion,leanburn and premixed combustion has the great potential to reduce NOx emission,which is very different from the conventional simple diffusion combustion concept.In the coupled flow field,the main stage airstream would further atomize the pilot stage fuel in the upstream and restrain the fuel diffusion,while the larger fuel particles would undergo backflow and the fuel distribution would be more uniform in the downstream.The upstream fuel particles would become larger and the downstream ones smaller when the step height is reduced.The upstream fuel particles would become larger when the main stage flow swirl strength is increased.The pressure drop distribution of the main stage flow has little influence on the size of fuel particles.