| 摘要 |
Dual fuel/air injectors are provided, including a conventional central diffusion flame fuel nozzle 12. A fuel injector 14 for pre-mixing fuel and air for low emissions combustion and coaxial to the central nozzle includes a plenum 30 about the central injector having an air inlet 32, an annular pre-mix chamber 34, a fuel injection region 36 between the pre-mix chamber and air inlet 32 and an outlet 40 defined in part by swirler vanes 38. Radially projecting fuel spokes 46 extend into the plenum 30 and are supplied fuel from a manifold 44. Apertures 52 in the spokes supply fuel in a circumferential direction to the incoming air. The spokes in the plenum define throat areas T which, in the aggregate, define a minimum cross-sectional area of the plenum 30. Differential air flows through the throats provide inverse differential fuel distribution in the throats whereby a uniform fuel/air mixture strength distribution occurs at the throats. The fuel/air pre-mix thus maintains uniform hot gas temperature distribution in the combustor reaction zone, minimizing the formation of pollutants in the exhaust.
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