Fuel nozzle with narrow-band acoustic damper

Patent metadata

Field	Value
Publication number	US-11041625-B2
Application number	US-201615381735-A
Country	US
Kind code	B2
Filing date	Dec 16, 2016
Priority date	Dec 16, 2016
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

A fuel nozzle assembly includes a fuel plenum for delivering fuel to a combustion zone of a combustor. At least one narrow-band acoustic damper is provided in the fuel nozzle assembly. The narrow-band acoustic damper is tuned to dampen pressure oscillations within the combustor. The narrow-band acoustic damper may be a quarter-wave tube mounted to a cap plate within or adjacent to the fuel nozzle assembly.

First claim

What is claimed is:

1. A combustor comprising:
a plurality of wedge-shaped bundled tube fuel nozzles arranged in a circumferential array, each wedge-shaped bundled tube fuel nozzle comprising:
a fuel plenum body comprising a forward plate extending in a radial direction, an aft plate axially spaced from the forward plate and extending in the radial direction, an outer sleeve extending in an axial direction between the forward plate and the aft plate, and a fuel plenum defined by the forward plate, the aft plate and the outer sleeve;
a fuel conduit in fluid communication with the fuel plenum; and
a plurality of mixing tubes extending through the fuel plenum body, each of the mixing tubes comprising an air inlet, a fuel port in fluid communication with the fuel plenum, and an outlet downstream of the aft plate;

the combustor further comprising an end cap having a circular shape, the end cap axially spaced from the aft plates of the plurality of wedge-shaped bundled tube fuel nozzles whereby an air plenum is defined between the aft plates and the end cap, the end cap upstream of a combustion zone, the end cap comprising a hot surface facing the combustion zone and an outer shroud that surrounds the plurality of wedge-shaped bundled tube fuel nozzles;
a plurality of quarter-wave tubes integrally formed with the end cap, the plurality of quarter-wave tubes extending from the hot surface of the end cap into the air plenum, each quarter-wave tube of the plurality of quarter-wave tubes corresponding to one of the wedge-shaped fuel nozzles, each quarter-wave tube extending along the axial direction from an entrance at an aft end of the quarter-wave tube to a reflective plane at a forward end of the quarter-wave tube;
wherein each quarter-wave tube defines an internal volume and the entrance of each quarter-wave tube permits unobstructed flow between the internal volume and the combustion zone;
wherein each quarter-wave tube comprises at least one purge hole defined in the forward end of the quarter-wave tube; and
wherein the plurality of quarter-wave tubes consists of an array of quarter-wave tubes positioned equidistant from the center of the hot surface of the end cap and equally circumferentially spaced around the center of the hot surface of the end cap, wherein no two quarter-wave tubes of the combustor are colinear along a line extending along the hot surface through the center of the hot surface, and wherein each quarter-wave tube in the plurality of quarter-wave tubes is closer to the outer shroud than the center of the hot surface of the end cap.

2. The combustor of claim 1 , wherein a length of each quarter-wave tube is defined by the distance between the entrance and the reflective plane.

3. The combustor of claim 2 , wherein the length of each quarter-wave tube corresponds to about one-quarter of a wavelength of a predetermined frequency.

4. The combustor of claim 1 , wherein the entrance of each quarter-wave tube is completely open to the combustion zone.

5. The combustor of claim 1 , wherein the entrance of each quarter-wave tube is defined at the hot surface of the end cap.

6. The combustor of claim 1 , wherein each quarter-wave tube is radially aligned with the fuel conduit of the corresponding wedge-shaped fuel nozzle and axially aft of the fuel conduit of the corresponding wedge-shaped fuel nozzle.

7. The combustor of claim 1 , wherein the end cap and the plurality of quarter-wave tubes are manufactured as a singular component.

8. The combustor of claim 1 , wherein the plurality of quarter-wave tubes is configured to dampen a frequency range from about 900 Hz to about 1.1 kHz.

9. The combustor of claim 1 , wherein the outer shroud is a single cylindrically shaped outer shroud that surrounds all of the plurality of quarter-wave tubes.

10. The combustor of claim 1 , wherein the outer shroud extends from the end cap beyond the reflective plane of each quarter-wave tube of the plurality of quarter-wave tubes to a flange.

11. A gas turbine, comprising:
a compressor;
a turbine;
a combustor disposed downstream from the compressor and upstream from the turbine, the combustor comprising:
a plurality of wedge-shaped bundled tube fuel nozzles arranged in a circumferential array and disposed upstream of a combustion zone, each wedge-shaped bundled tube fuel nozzle comprising:
a fuel plenum body;
a fuel plenum defined by the fuel plenum body;
a fuel conduit in fluid communication with the fuel plenum; and
a plurality of mixing tubes extending through the fuel plenum body, each of the mixing tubes comprising an air inlet, a fuel port in fluid communication with the fuel plenum, and an outlet downstream of the fuel plenum body;

the combustor further comprising an end cap having a circular shape, the end cap axially spaced from the fuel plenum bodies of the plurality of wedge-shaped bundled tube fuel nozzles whereby an air plenum is defined between the fuel plenum bodies and the end cap, the end cap upstream of the combustion zone, the end cap comprising a hot surface facing the combustion zone and an outer shroud that surrounds the plurality of wedge-shaped bundled tube fuel nozzles;
a plurality of quarter-wave tubes integrally formed with the end cap, each quarter-wave tube of the plurality of quarter-wave tubes extending axially upstream from the end cap from an aft end to a forward end, each quarter-wave tube of the plurality of quarter-wave tubes corresponding to one of the wedge-shaped bundled tube fuel nozzles;
wherein each quarter-wave tube comprises an entrance at the aft end and a reflective plane at the forward end;
wherein each quarter-wave tube defines an internal volume and the entrance of each quarter-wave tube permits unobstructed flow between the internal volume and the combustion zone;
wherein the quarter-wave tube comprises at least one purge hole defined in the forward end of the quarter-wave tube; and
wherein the plurality of quarter-wave tubes consists of an array of quarter-wave tubes positioned equidistant from the center of the hot surface of the end cap and equally circumferentially spaced around the center of the hot surface of the end cap, wherein no two quarter-wave tubes of the combustor are colinear along a line extending along the hot surface through the center of the hot surface, and wherein each quarter-wave tube in the plurality of quarter-wave tubes is closer to the outer shroud than the center of the hot surface of the end cap.

12. The gas turbine of claim 11 , wherein a length of each quarter-wave tube is defined by the distance between the entrance and the reflective plane.

13. The gas turbine of claim 12 , wherein the length of each quarter-wave tube corresponds to about one-quarter of a wavelength of a predetermined frequency.

14. The gas turbine of claim 11 , wherein the entrance of each quarter-wave tube is completely open to the combustion zone.

15. The gas turbine of claim 11 , wherein each quarter-wave tube extends through the end cap such that the entrance of each quarter-wave tube is flush with the hot surface of the end cap.

16. The gas turbine of claim 11 , wherein each quarter-wave tube is radially aligned with the fuel conduit of the corresponding wedge-shaped bundled tube fuel nozzle and axially aft of the fuel conduit of the corresponding wedge-shaped bundled tube fuel nozzle.

Assignees

• Gen Electric

Inventors

• Purcell Timothy James
• Schuermans Bruno
• Stoia Lucas John
• Bethke Sven Georg

Classifications

• F23R3/286 Primary

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

• F23R2900/00014

  Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators · CPC title