Fuel injector to facilitate reduced NOx emissions in a combustor system

An annular fuel injection nozzle comprising:

• a fuel injector housing comprising an upstream face, an opposite downstream face, and a peripheral wall extending therebetween, the fuel injector housing defined about a center longitudinal axis of the annular fuel injection nozzle;
• an inner oxidizer flow path, about the center longitudinal axis, having an inner swirler therein;
• an intermediate oxidizer flow path radially outward of the inner oxidizer flow path, concentric with the center longitudinal axis, having an intermediate swirler therein;
• an annular fuel manifold radially outward of the intermediate oxidizer flow path, concentric with the center longitudinal axis;
• and
• an outer oxidizer flow path radially outward of the annular fuel manifold, concentric with the center longitudinal axis, having an outer swirler therein,
• wherein an oxidizer stream enters the fuel injector housing through the upstream face of the fuel injector housing,
• wherein a first portion of the oxidizer stream is diverted to the inner oxidizer flow path and through a centerbody of the fuel injection nozzle via the inner swirler as an inner oxidizer flow stream,
• wherein a second portion of the oxidizer stream is diverted to the intermediate oxidizer flow path via the intermediate swirler as an intermediate oxidizer flow stream, and
• wherein a third portion of the oxidizer stream is diverted to the outer oxidizer flow path via the outer swirler as an outer oxidizer flow stream,
• the annular fuel manifold comprising:
• a forward portion and an aft portion including an aft face;
• and
• a plurality of fuel injector outlets configured downstream of the inner swirler and the outer swirler and circumferentially spaced about at least one of a sidewall defining the aft portion of the annular fuel manifold or downstream of the inner swirler, the intermediate swirler and the outer swirler and circumferentially spaced about an aft face of the aft portion of the annular fuel manifold,
• wherein the plurality of fuel injector outlets are configured to inject a fuel flow in a downstream direction along a mid-plane of the annular fuel manifold, wherein the mid-plane is defined as a radial median between an innermost and outermost radius of the annular fuel manifold,
• wherein the fuel flow exiting the annular fuel manifold undergoes initial interaction with the intermediate oxidizer stream and the outer oxidizer stream, downstream of the intermediate swirler and the outer swirler, thereby providing a mixed stream,
• wherein the mixed stream remains separated from the inner oxidizer stream until the mixed stream undergoes circumferential and radial mixing with the inner oxidizer stream passing through the inner swirler, downstream of the inner swirler and the plurality of fuel injector outlets, and
• wherein one or more of the plurality of fuel injector outlets comprises a plurality of fuel exit orifices, wherein at least one orifice of the plurality of fuel exit orifices is fitted with a fuel injector tip.

A combustor assembly comprising:

• a combustion liner comprising a center longitudinal axis, a forward end and an aft end;
• and
• an annular fuel injection nozzle, coupled adjacent to the forward end of the combustion liner, the annular fuel injection nozzle comprising:
• a fuel injector housing comprising an upstream face, an opposite downstream face, and a peripheral wall extending therebetween, the fuel injector housing defined about the center longitudinal axis;
• an inner oxidizer flow path, about the center longitudinal axis, having an inner swirler therein;
• an intermediate oxidizer flow path radially outward of the inner oxidizer flow path, concentric with the center longitudinal axis, having an intermediate swirler therein;
• an annular fuel manifold radially outward of the intermediate oxidizer flow path, concentric with the center longitudinal axis;
• and
• an outer oxidizer flow path radially outward of the annular fuel manifold, concentric with the center longitudinal axis, having an outer swirler therein,
• wherein an oxidizer stream enters the fuel injector housing through the upstream face of the fuel injector housing,
• wherein a first portion of the oxidizer stream is diverted to the inner oxidizer flow path and through a centerbody of the fuel injection nozzle via the inner swirler as an inner oxidizer flow stream,
• wherein a second portion of the oxidizer stream is diverted to the intermediate oxidizer flow path via the intermediate swirler as an intermediate oxidizer flow stream, and
• wherein a third portion of the oxidizer stream is diverted to the outer oxidizer flow path via the outer swirler as an outer oxidizer flow stream,
• the annular fuel manifold comprising:
• a forward portion and an aft portion including an aft face;
• and
• a plurality of fuel injector outlets defined in the aft portion, downstream of the inner swirler and the outer swirler,
• wherein the plurality of fuel injector outlets are configured to inject a fuel flow in a downstream direction along a mid-plane of the annular fuel manifold, wherein the mid-plane is defined as a radial median between an innermost and outermost radius of the annular fuel manifold,
• wherein the fuel flow exiting the annular fuel manifold undergoes initial interaction with the intermediate oxidizer stream and the outer oxidizer stream, downstream of the intermediate swirler and the outer swirler, thereby providing a mixed stream, and
• wherein the mixed stream remains separated from the inner oxidizer stream until the mixed stream undergoes circumferential and radial mixing with the inner oxidizer stream passing through the inner swirler, downstream of the inner swirler and the plurality of fuel injector outlets.

A combustor assembly comprising:

• a combustion liner comprising a center longitudinal axis, a forward end and an aft end:
• and
• an annular fuel injection nozzle, coupled adjacent to the forward end of the combustion liner, the annular fuel injection nozzle comprising:
• a fuel injector housing comprising an upstream face, an opposite downstream face, and a peripheral wall extending therebetween, the fuel injector housing defined about the center longitudinal axis;
• an inner oxidizer flow path, about the center longitudinal axis, having an inner swirler therein;
• an intermediate oxidizer flow path radially outward of the inner oxidizer flow path, concentric with the center longitudinal axis, having an intermediate swirler therein;
• an annular fuel manifold radially outward of the second oxidizer flow path, concentric with the center longitudinal axis;
• and
• an outer oxidizer flow path radially outward of the annular fuel manifold, concentric with the center longitudinal axis, having an outer swirler therein,
• wherein an oxidizer stream enters the fuel injector housing through the upstream face of the fuel injector housing,
• wherein a first portion of the oxidizer stream is diverted to the inner oxidizer flow path and through a centerbody of the fuel injection nozzle via the inner swirler as an inner oxidizer flow stream,
• wherein a second portion of the oxidizer stream is diverted to the Intermediate oxidizer flow path via the intermediate swirler as an intermediate oxidizer flow stream, and
• wherein a third portion of the oxidizer stream is diverted to the outer oxidizer flow path via the outer swirler as an outer oxidizer flow stream, and
• the annular fuel manifold comprising:
• a forward portion and an aft portion including an aft face;
• and
• a plurality of fuel injector outlets defined in the aft portion, downstream of the inner swirler and the outer swirler,
• wherein the plurality of fuel injector outlets are configured to inject a fuel flow in a downstream direction along a mid-plane of the annular fuel manifold, wherein the mid-plane is defined as a radial median between an innermost and outermost radius of the annular fuel manifold,
• wherein the fuel flow exiting the annular fuel manifold undergoes initial interaction with the intermediate oxidizer stream and the outer oxidizer stream, downstream of the intermediate swirler and the outer swirler, thereby providing a mixed stream,
• wherein the mixed stream remains separated from the inner oxidizer stream until the mixed stream undergoes circumferential and radial mixing upon interaction with the inner oxidizer stream downstream of the inner swirler and the plurality of fuel injector outlets, and
• wherein the plurality of fuel injector outlets comprises a plurality of fuel exit orifices, wherein at least one orifice of the plurality of fuel exit orifices is fitted with an injector tip, wherein the injector tip comprises an additional fuel manifold that operates over a limited power range and is selectively operable such that the additional fuel manifold is switched off during operation beyond the limited power range.