Prefilming air blast (PAB) pilot having annular splitter surrounding a pilot fuel injector

Patent metadata

Field	Value
Publication number	US-10184665-B2
Application number	US-201514735732-A
Country	US
Kind code	B2
Filing date	Jun 10, 2015
Priority date	Jun 10, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A fuel nozzle is provided for a gas turbine engine, and can include a pilot fuel injector having an axially-elongated, inner pilot centerbody wall and an outer pilot centerbody wall, with the axially-elongated, inner pilot centerbody wall extending from an upstream end to an annular fuel passage defining the downstream end of the pilot fuel injector. The fuel passage intersects with the inner pilot centerbody wall at a pilot fuel metering orifice. The fuel nozzle also includes a pilot fuel film surface downstream from the annular fuel passage and an annular splitter surrounding the pilot fuel injector. The annular splitter comprises, in axial sequence: an upstream section, a splitter throat having a diameter that is larger than a downstream diameter defined by the pilot fuel film surface, and a downstream diverging surface having an average diverging angle of about 24° to about 40° in relation to a centerline axis.

First claim

What is claimed is:

1. A fuel nozzle of a gas turbine engine, comprising:
a pilot fuel injector comprising an axially-elongated, inner pilot centerbody wall and an outer pilot centerbody wall, wherein the axially-elongated, inner pilot centerbody wall extends from an upstream end to an annular fuel passage defining a first downstream end of the pilot fuel injector, the annular fuel passage intersecting with the axially-elongated, inner pilot centerbody wall at a pilot fuel metering orifice;
a pilot fuel film surface downstream from the annular fuel passage and in fluid communication with a pilot fuel cartridge, wherein the pilot fuel cartridge is positioned between the axially-elongated, inner pilot centerbody wall and the outer pilot centerbody wall to provide a swirl path for a pilot supply line to the pilot fuel film surface, and wherein an inner purge air cavity is defined between the axially-elongated, inner pilot centerbody wall and the pilot fuel cartridge and extends to an inner purge air inlet port that is upstream from the pilot fuel film surface;
an annular splitter surrounding the pilot fuel injector, wherein the annular splitter comprises, in axial sequence:
an upstream section,
a splitter throat downstream of the pilot fuel film surface and having a diameter that is larger than a downstream diameter defined by the pilot fuel film surface, and
a downstream diverging surface having a first average diverging angle of between 30° and 40° in relation to a centerline axis, and

an inner swirler comprising a first radial array of inner swirl vanes extending between the outer pilot centerbody wall and the upstream section of the annular splitter,
wherein the inner swirl vanes define a first trailing edge with a first angle between 10° and 35° relative to the centerline axis.

2. The fuel nozzle as in claim 1 , wherein an inner air circuit is defined from the inner swirler to an intersection with the pilot fuel film surface with a first constant passage spacing between the outer pilot centerbody wall and the upstream section of the annular splitter.

3. The fuel nozzle as in claim 2 , further comprising:
an annular venturi surrounding the pilot fuel injector and the annular splitter, the annular venturi having an exit positioned axially downstream of the pilot fuel injector and the annular splitter.

4. The fuel nozzle as in claim 3 , wherein the annular venturi comprises, in axial sequence, a cylindrical upstream section, a venturi throat of minimum diameter, and a downstream diverging section.

5. The fuel nozzle as in claim 4 , wherein the downstream diverging section of the annular venturi has a second average diverging angle between 28° and 44° in relation to the centerline axis.

6. The fuel nozzle as in claim 4 , further comprising:
an outer air swirler comprising a second radial array of outer swirl vanes extending between the annular splitter and the annular venturi.

7. The fuel nozzle as in claim 6 , wherein the outer swirl vanes, the annular splitter, and the inner swirl vanes physically support the pilot fuel injector.

8. The fuel nozzle as in claim 6 , wherein the outer swirl vanes define a second trailing edge with a second angle between 40° and 60° relative to the centerline axis.

9. The fuel nozzle as in claim 6 , wherein the outer swirl vanes define a second trailing edge with a second angle between 40° and 55° relative to the centerline axis.

10. The fuel nozzle as in claim 6 , wherein an outer air circuit is defined from the outer air swirler to a second downstream end of the annular splitter with a second constant passage spacing between the annular venturi and the annular splitter.

11. The fuel nozzle as in claim 8 , wherein the axially-elongated, inner pilot centerbody wall has a diverging-converging orientation with respect to the centerline axis to define a hollow tube having an upstream diameter, a throat, and a downstream diameter, and wherein the throat has an inner diameter that is less than both of the upstream diameter and the downstream diameter.

12. The fuel nozzle as in claim 11 , wherein the pilot fuel injector further comprises a center air circuit positioned at the upstream end of the axially-elongated, inner pilot centerbody wall, wherein the center air circuit is defined by a center swirler having center swirl vanes.

13. The fuel nozzle as in claim 12 , wherein the center swirl vanes define a third trailing edge having a third angle with respect to the centerline axis that is between 40° and 50°.

14. The fuel nozzle as in claim 11 , wherein the pilot fuel film surface has a constant diameter.

15. The fuel nozzle as in claim 3 , further comprising:
a main ring support;
a main fuel conduit; and
an annular main injection ring surrounding the annular venturi and connected to the main ring support, the annular main injection ring comprising a main fuel gallery extending in a circumferential direction,
wherein the main fuel gallery is fluidly coupled to, and supplied with fuel by, the main fuel conduit.

16. The fuel nozzle as in claim 15 , the annular main injection ring further comprising:
at least one pilot fuel gallery, the at least one pilot fuel gallery adjacent to, and radially spaced from, the main fuel gallery,
wherein the at least one pilot fuel gallery surrounds the main fuel gallery,
wherein a first cross-section of the main fuel gallery is axially-elongated, and
wherein a second cross-section of the at least one pilot fuel gallery is axially-elongated.

17. The fuel nozzle as in claim 15 , further comprising:
an outer body, the outer body radially outward from and surrounding the annular main injection ring; and
an inner body, the inner body radially inward from and surrounded by the annular main injection ring;
wherein the outer body and the inner body define a void therebetween with the annular main injection ring contained within the void.

18. The fuel nozzle as in claim 17 , the outer body further comprising:
an array of recesses defining at least one spray well, the at least one spray well comprising an opening in the outer body, the opening in fluid communication with the annular main injection ring.

19. A fuel nozzle of a gas turbine engine, comprising:
a pilot fuel injector comprising an axially-elongated, inner pilot centerbody wall and an outer pilot centerbody wall, wherein the axially-elongated, inner pilot centerbody wall extends from an upstream end to an annular fuel passage defining a downstream end of the pilot fuel injector, the annular fuel passage intersecting with the axially-elongated, inner pilot centerbody wall at a pilot fuel metering orifice;
a pilot fuel film surface downstream from the annular fuel passage and in fluid communication with a pilot fuel cartridge, wherein the pilot fuel cartridge is positioned between the axially-elongated inner pilot centerbody wall and the outer pilot centerbody wall to provide a swirl path for a pilot supply line to the pilot fuel film surface, and wherein an inner purge air cavity is defined between the axially-elongated inner pilot centerbody wall and the pilot fuel cartridge and extends to an inner purge air inlet port that is upstream from the pilot fuel film surface, and further wherein an outer purge air cavity is defined between the pilot fuel cartridge and the outer pilot centerbody wall and extends to an outer purge air inlet port;
an annular splitter surrounding the pilot fuel injector, wherein the annular splitter comprises, in axial sequence:
an upstream section; and
a splitter throat downstr

Assignees

• Gen Electric

Inventors

• Benjamin Michael Anthony
• Mancini Alfred Albert
• Chandrasekaran Rameshkumar Muthuvel

Classifications

• F23D11/107

  at least one of both being subjected to a swirling motion · CPC title

• F23R3/14 Primary

  by using swirl vanes · CPC title

• F23R3/286 Primary

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F02C7/22

  Fuel supply systems · CPC title

• F23D2900/11101

  Pulverising gas flow impinging on fuel from pre-filming surface, e.g. lip atomizers · CPC title