Pilot nozzles in gas turbine combustors

A gas turbine having a combustor that includes a fuel nozzle, wherein the fuel nozzle comprises:

• an axially elongated centerbody;
• an axially elongated peripheral wall formed about the centerbody so to define a primary flow annulus therebetween, wherein the peripheral wall defines a central axis of the fuel nozzle;
• a primary fuel supply and a primary air supply in fluid communication with an upstream end of the primary flow annulus;
• and
• a pilot nozzle comprising a downstream section of the centerbody, the pilot nozzle including:
• tubes, defined within a centerbody wall, the tubes including air tubes and mixing tubes, wherein each of the tubes axially elongate between an inlet defined through an upstream face of the pilot nozzle and an outlet formed through a downstream face of the pilot nozzle;
• a secondary air supply configured so to fluidly communicate with the inlet of each of the air and mixing tubes;
• a fuel port positioned between the inlet and the outlet of each of the mixing tubes for connecting each of the mixing tubes to a secondary fuel supply;
• and
• an uninterrupted sidewall sealing structure between the inlet and the outlet of each of the air tubes that segregates an air flow therein from the secondary fuel supply;
• wherein a plurality of the tubes are configured as canted tubes that are angled relative the central axis of the fuel nozzle so to induce a downstream swirling flow in a collective discharge therefrom, the canted mixing tubes each comprising a tangentially angled orientation relative to the central axis of the fuel nozzle at the outlet formed through the downstream face of the pilot nozzle;
• and
• wherein:
• a plurality of the mixing tubes are configured as the canted tubes;
• and
• a plurality of the air tubes are configured as the canted tubes.