A dual-fuel fuel nozzle includes a centerbody that at least partially defines an air plenum therein. A tip body is disposed at a downstream end of the centerbody. The tip body includes an upstream side that is axially spaced from a downstream side. The downstream side defines a circular slot and a circular recess that is positioned radially inwardly from the circular slot. The circular recess includes a floor and a side wall, The floor defines an insert opening and the side wall defines an annular groove that includes an undercut surface. The tip body further defines a plurality of orifices annularly arranged around the insert opening radially inward from the side wall of the circular recess. Each orifice includes an inlet that is in fluid communication with the air plenum and an outlet that is oriented towards the undercut surface.

Emissions of NO.sub.x and/or CO are reduced at the stack by systems and methods wherein a primary fuel is thoroughly mixed with a specific range of excess combustion air. The primary fuel-air mixture is then discharged and anchored within a combustion chamber of a burner. Further, the systems and methods provide for dynamically controlling NO.sub.x content in emissions from a furnace by adjusting the flow of primary fuel and of a secondary stage fuel, and in some cases controlling the amount or placement of combustion air into the furnace.

Implementations of a combustor assembly yield low emissions, require low power, are suitable for alternate liquid fuels, including highly viscous fuels, and are scalable for various heat release rates. The combustor assembly includes a fuel injector and a swirler. The fuel injector may include a choke portion and a spacer. The choke portion is disposed just upstream of an outlet of a liquid fuel conduit and prevents atomizing gas from interrupting continuous flow of the liquid fuel through the liquid fuel conduit. The spacer is disposed downstream of the outlet to precisely control the gap and thus, bifurcation of atomizing gas flow, between the outlet of liquid fuel conduit and an inlet of an orifice plate. The swirler is disposed radially outwardly and adjacent the fuel injector and includes a plurality of angled vanes.

The present disclosure is directed to a dual-fuel fuel nozzle that includes a center body having a tube shape and a gas fuel plenum defined within the center body. The duel-fuel fuel nozzle also includes a ring manifold defining a liquid fuel plenum disposed within the center body. The duel-fuel fuel nozzle further includes a plurality of radially oriented fuel injectors in fluid communication with the liquid fuel plenum. Additionally, the duel-fuel fuel nozzle includes an inner fuel tube extending axially within the center body. A portion of the inner fuel tube extends helically about an axial centerline of the center body. The inner fuel tube is in fluid communication with an axially oriented fuel injector. Furthermore, the duel-fuel fuel nozzle includes first fuel tube extending helically around a portion of the inner fuel tube within the center body. The first fuel tube is fluidly coupled to the fuel plenum.

A fuel-fired burner includes a combustion air inlet for receiving combustion air coupled to a combustion air nozzle at an input to a second chamber within a burner housing spaced apart from a third chamber within the second chamber. The combustion air nozzle directs the combustion air into the third chamber. A fuel inlet coupled to a burner nozzle secured to a burner mounting plate has a recycle port for receiving hot exhaust gas provided to an exhaust gas path. A jet pump located entirely inside the burner housing is configured to receive the hot exhaust gas from the exhaust gas path. The jet pump operates by flowing the combustion air through the combustion air nozzle which suctions in the hot exhaust gas through the recycle port into the exhaust gas path then into a gas mixing zone for mixing the hot exhaust gas and the combustion air.

A nozzle includes a nozzle body defining a longitudinal axis. The nozzle body includes an inner air passage fed by a radial swirler and having a converging conical cross-section. A first fuel circuit is radially outboard from the air passage with respect to the longitudinal axis. A second fuel circuit is radially outboard from the first fuel circuit with respect to the longitudinal axis, wherein each of the first fuel circuit and the second fuel circuit extends from a respective fuel circuit inlet to a respective annular fuel circuit outlet. An outer air passage is defined between a fuel circuit outer wall and an outer air passage wall, wherein the outer air passage is a converging non-swirling outer air passage.

A system and method for igniting liquid fuel in a gas turbine combustor is provided. A liquid fuel cartridge, which is located within the head end, is in flow communication with a liquid fuel supply. A gaseous fuel nozzle is located proximate the liquid fuel cartridge and in flow communication with an auxiliary gaseous fuel supply. A controller is in communication with the liquid fuel supply, the auxiliary gaseous fuel supply, and an igniter located proximate or within the head end. The controller is configured to sequentially: initiate a gaseous fuel flow from the auxiliary gaseous fuel supply to the gaseous fuel nozzle; initiate the igniter to combust the gaseous fuel flow; initiate a liquid fuel flow from the liquid fuel supply to the liquid fuel cartridge; and terminate the gaseous fuel flow from the auxiliary gaseous fuel supply.

The present disclosure is directed to a dual-fuel fuel nozzle including a center body having a tube shape and a gas fuel plenum defined within the center body. The fuel nozzle also includes a plurality of turning vanes extending radially outward from the center body. Each turning vane includes at least one fuel port in fluid communication with the gas fuel plenum. A plurality of apertures is disposed through the plurality of turning vanes. The fuel nozzle further includes a ring manifold disposed within the center body downstream of the plurality of turning vanes. Additionally, the fuel nozzle includes a first fuel tube extending helically around a centerline of the center body. Furthermore, the fuel nozzle includes an air shield disposed within the center body and extending circumferentially around the first fuel tube.

The present disclosure is directed to a nozzle assembly including a header manifold and a ring manifold, which defines a liquid fuel plenum, spaced from the header manifold. An outer sleeve connects to the ring manifold, and a nozzle body connects to the outer sleeve. The ring manifold, the outer sleeve, and the nozzle body define a fluid chamber. An inner fuel tube extends from the header manifold to the nozzle body. A portion of the inner fuel tube extends helically about an axial centerline of the nozzle assembly between the ring manifold and the nozzle body. A first fuel tube extends helically around a portion of the inner fuel tube. The first fuel tube fluidly couples the liquid fuel plenum to the header manifold. A second fuel tube extends helically around a portion of the inner fuel tube and fluidly couples the liquid fuel plenum to the header manifold.

A fuel nozzle body having a rearward end and a front end with an outer tube which extends from the rearward end to the front end and has radial openings for a first fuel in the region of the front end, and an inner tube which is arranged concentrically to the outer tube and which opens in the region of the front end into a nozzle head, which has additional openings for a second fuel, wherein, in the region of the front end, the inner tube is guided in the outer tube by two fits which are arranged axially between the radial openings and the additional openings, and wherein the first fit closest to the radial openings is configured as a circumferential web around the inner tube, and wherein the second fit is configured with at least one interruption on the perimeter.