气动多点供油装置油雾特性研究

Research on Spray Characteristics of an Air-AssistedMulti-Point Fuel Supply Device

关键词:  气动多点供油  雾化  燃油流量  燃烧技术

Key words:  Air-assisted multi-point fuel supply  Atomization  Fuel flux  Combustion technology

摘要:

为了研究一种部分预蒸发预混合气动多点供油装置的雾化性能，使用燃油收集器和相位多普勒粒子分析仪（PDA），获得了多点供油装置下游的燃油流量分布和索太尔平均直径分布，并使用数值模拟方式获得了供油装置内外流场形态和油气动量比变化趋势，分析了流量与粒径分布的形成原因。结果表明，多点供油装置下游燃油主要集中在分布管后半段，在该位置对应的下游喷雾场内可以保持相对均匀的燃油流量分布；油雾场中雾化较好的区域可近似为一个向外侧倾斜的矩形，雾化索太尔平均直径在20μm左右。多点供油装置内部流线的变化导致分布管上各小孔流量不均，进而使分布管下游油气动量比产生变化，是形成其下游的燃油流量分布和索太尔平均直径分布趋势的最直接原因。

Abstract:

In order to investigate the atomization performance of an partial premixed and evaporated air-assisted multi-point fuel supply device suitable for cavity flame stabilizer, the fuel flow distribution and the Sauter mean diameter (SMD) distribution downstream of the multi-point fuel supply device were obtained by a fuel collector and a phase Doppler particle analyzer (PDA). The flow field inside and outside the fuel supply device, together with the fuel-to-air momentum ratio distribution, were obtained through numerical simulation, which can be seen as the cause of the flux and particle size distribution. The results show that, the downstream fuel of the multi-point fuel supply device is mainly concentrated in the rear section of the distribution pipe. A relatively uniform fuel flow distribution can be acquired inside the downstream spray field corresponding to this location. The well-atomized region in the spray field is approximately an outward inclining belt with a measured SMD around 20μm. Changes in the internal flow lines of the multi-point fueling device lead to an unequal flow in the orifices on the distribution pipe, which in turn causes a change in the fuel-to-air ratio downstream of the distribution pipe, directly forming the distribution of the downstream fuel flow and the Sauter mean diameter.