FUEL INJECTOR WITH PREMIX PILOT NOZZLE

• US 20150159875A1
• Filed: 12/11/2013
• Published: 06/11/2015
• Est. Priority Date: 12/11/2013
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Berry, Jonathan Dwight, Hughes, Michael John, Edwards, Kara Johnston
• Granted Patent: US 9,435,540 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02C 7/222 Fuel flow conduits, e.g. manifolds
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F23R 2900/03343 Pilot burners operating in premixed mode
• CPC Class Codes: F23R 3/286 having fuel-air premixing devices F23R3/30 takes precedence
• CPC Class Codes: F23R 3/343 Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00

Abstract

An apparatus for injecting premixed fuel and air through a center body and into the combustion zone of a gas turbine includes a fuel injector nozzle with a premix pilot nozzle having a plurality of premix passages in fluid communication with an air supply and a fuel supply that premixes air and fuel within the premix passages. The apparatus has either an active or passive fuel feed control. Fuel can be fed to the apparatus either conventionally or as a breech load circuit integrated into the oil cartridge. Fuel can be supplied passively via a fuel channel connecting the swozzle fuel plenum to the premix passages. Alternatively, fuel can be injected from the oil cartridge into the premix passages.

Claims

1. A fuel injector for a gas turbine engine, comprising:

a. an axially elongating peripheral wall defining an outer envelope of the injector, the wall having an interior surface defining an axially elongating interior cavity;

b. a hollow, axially elongating center body disposed within the interior cavity of the injector, the center body being defined by an upstream end and a downstream end disposed axially opposite the upstream end, the center body being defined by an outer surface and an inner surface facing opposite the outer surface, the inner surface defining an axially elongating interior passage;

c. a primary air flow channel being defined by an annular space disposed between the outer surface of the center body and the interior surface of the peripheral wall;

d. a swozzle including a plurality of swirler vanes extending radially across the primary air flow channel, at least one of the swirler vanes defining at least one fuel conduit having an inlet at one end thereof and an outlet at an opposite end thereof, the at least one fuel conduit being configured and disposed in fluid communication with the primary air flow channel;

e. a premix pilot nozzle having an upstream end connected to the downstream end of the center body, the premix pilot nozzle having a downstream end disposed axially opposite the upstream end of the premix pilot nozzle, the premix pilot nozzle defining a plurality of axially elongated, hollow premix passages, each premix passage having an upstream end disposed near the downstream end of the center body and defining a fill opening that admits fluid to flow into the hollow premix passage, each premix passage having a downstream end disposed axially opposite the upstream end of the premix passage and disposed near the downstream end of the premix pilot nozzle, each downstream end of each premix passage defining an exit opening that allows fluid to discharge from the hollow premix passage; and

f. a fuel supply passage having an upstream end configured for connection to a source of fuel, the fuel supply passage having a downstream end disposed at the downstream end of the center body and fluidly connected to the upstream ends of the plurality of premix passages.

2. The fuel injector of claim 1, wherein the center body has a centrally symmetric axial centerline and each premix passage has a premix axis about which its defining walls are concentrically defined, and at least one of the premix passages is an angled premix passage such that the premix axis of the at least one angled premix passage is disposed at an acute angle with respect to the centrally symmetric axial centerline of the center body.

3. The fuel injector of claim 2, wherein the acute angle of each angled premix passage is configured and disposed so as to impart to the flow direction of a fuel-air mix that discharges from the exit opening of each premix passage a radially inwardly directed component in a direction that moves toward the centrally symmetric axial centerline of the center body.

4. The fuel injector of claim 1, wherein the swozzle further defines a plurality of curtain air feed holes, each curtain air feed hole being configured and disposed to provide fluid communication between the primary air flow channel and the interior passage of the center body.

5. The fuel injector of claim 1, wherein the fill opening of each hollow premix passage communicates fluidly with the interior passage of the center body.

6. The fuel injector of claim 1, wherein each of the plurality of premix passages is defined by a separate tube.

7. The fuel injector of claim 1, wherein the premix pilot nozzle is defined by a solid metal stock and each of the plurality of premix passages is defined by a separate bore through the metal stock.

8. The fuel injector of claim 1, wherein a first set of premix passages of the plurality of premix passages is arranged in a first circular grouping and a second set of premix passages of the plurality of premix passages is arranged in a second circular grouping that is disposed radially inwardly with respect to the first circular grouping of premix passages.

9. The fuel injector of claim 7, wherein the center body has a centrally symmetric axial centerline and each premix passage has a premix axis about which its defining walls are concentrically defined, and at least one of the premix passages is an angled premix passage such that the premix axis of the at least one angled premix passage is disposed at an acute angle with respect to the centrally symmetric axial centerline of the center body.

10. The fuel injector of claim 1, wherein the center body includes a fuel cartridge defining a central fuel passage through which an actively controlled supply of fuel flows in the downstream direction.

11. The fuel injector of claim 10, wherein the center body has a centrally symmetric axial centerline and each premix passage has a premix axis about which its defining walls are concentrically defined, and at least one of the premix passages is an angled premix passage such that the premix axis of the at least one angled premix passage is disposed at an acute angle with respect to the centrally symmetric axial centerline of the center body.

12. The fuel injector of claim 11, wherein the acute angle of each angled premix passage is configured and disposed so as to impart to the flow direction of a fuel-air mix that discharges from the exit opening of each premix passage a radially inwardly directed component in a direction that moves toward the centrally symmetric axial centerline of the center body.

13. The fuel injector of claim 1, further comprising an inner cylindrical wall disposed internally of the center body and defining a hollow interior of the center body through which an actively controlled supply of air and/or fuel can flow in the downstream direction.

14. The fuel injector of claim 13, wherein the center body has a centrally symmetric axial centerline and each premix passage has a premix axis about which its defining walls are concentrically defined, and at least one of the premix passages is an angled premix passage such that the premix axis of the at least one angled premix passage is disposed at an acute angle with respect to the centrally symmetric axial centerline of the center body.

15. The fuel injector of claim 14, wherein the acute angle of each angled premix passage is configured and disposed so as to impart to the flow direction of a fuel-air mix that discharges from the exit opening of each premix passage a radially inwardly directed component in a direction that moves toward the centrally symmetric axial centerline of the center body.

16. The fuel injector of claim 1, further comprising a plurality of radial air supply tubes, each radial air supply tube extending through the axially elongating peripheral wall and fluidly connecting with at least one of the fill openings of one of the premix passages.

17. The fuel injector of claim 1, wherein the fuel supply passage includes at least one axially extending fuel conduit, the at least one axially extending fuel conduit being configured and disposed in fluid communication with both the at least one fuel conduit of the swozzle and at least one premix passage.

18. The fuel injector of claim 17, further comprising an inner cylindrical wall disposed internally of the center body and defining a hollow interior of the center body through which an actively controlled supply of air and/or fuel can flow in the downstream direction.

19. The fuel injector of claim 17, further comprising a plurality of radial air supply tubes, each radial air supply tube extending through the axially elongating peripheral wall and fluidly connecting with at least one of the fill openings of one of the premix passages.

20. The fuel injector of claim 17, wherein the center body has a centrally symmetric axial centerline and each premix passage has a premix axis about which its defining walls are concentrically defined, and at least one of the premix passages is an angled premix passage such that the premix axis of the at least one angled premix passage is disposed at an acute angle with respect to the centrally symmetric axial centerline of the center body.