System and method for tube level air flow conditioning

Patent metadata

Field	Value
Publication number	US-9765973-B2
Application number	US-201313797986-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 12, 2013
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A system includes a multi-tube fuel nozzle. The multi-tube fuel nozzle includes multiple mixing tubes. Each mixing tube includes an annular wall disposed about a central passage and an air inlet region configured to be disposed about a fuel injector extending into the central passage. The central passage extends from an upstream end to a downstream end of the annular wall relative to a direction of flow through the central passage. The air inlet region includes an air entry surface of the annular wall that gradually decreases in diameter in the direction of flow.

First claim

The invention claimed is:

1. A system for injecting fuel, comprising:
a multi-tube fuel nozzle, comprising:
a plurality of mixing tubes wherein each mixing tube comprises:
an annular wall disposed about a central passage, wherein the central passage extends from an upstream end to a downstream end of the annular wall relative to a direction of flow through the central passage; and
an air inlet region configured to be disposed about a fuel injector extending into the central passage, wherein the air inlet region comprises an air entry region of the annular wall comprises a bell-shaped portion;
wherein an outer diameter of each mixing tube initially increases from the upstream end prior to the bell-shaped portion and then continuously decreases through the bell-shaped portion in the direction of flow toward the downstream end, and an inner diameter of each mixing tube initially decreases from the upstream end prior to the bell-shaped portion and then remains constant in the direction of flow toward the downstream end of the annular wall.

2. The system of claim 1 , wherein the air entry surface comprises a contoured surface at the upstream end of the annular wall.

3. The system of claim 2 , wherein the contoured surface comprises a contoured outer surface, a contoured inner surface, and a contoured turn portion disposed between the contoured outer surface and the contoured inner surface.

4. The system of claim 1 , comprising a plurality of fuel injectors, wherein each mixing tube has one of the fuel injectors disposed in the upstream end of the mixing tube.

5. The system of claim 1 , comprising a gas turbine engine or a combustor having the multi-tube fuel nozzle.

6. The system of claim 1 , wherein the plurality of mixing tubes comprises at least 50 mixing tubes.

7. The system of claim 1 , wherein the multi-tube fuel nozzle comprises a plurality of fuel injectors and a common fuel plenum, and wherein each mixing tube of the plurality of mixing tubes has a first end and a second end, a respective first end of each mixing tube of the plurality of mixing tubes is disposed about a respective fuel injector of the plurality of fuel injectors, and each mixing tube of the plurality of mixing tubes is coupled to the common fuel plenum to receive fuel.

8. The system of claim 1 , wherein the multi-tube fuel nozzle comprises a plurality of fuel nozzle sectors, and each fuel nozzle sector comprises at least 50 mixing tubes.

9. The system of claim 1 , wherein the plurality of mixing tubes is arranged concentrically in a plurality of rows about a central axis of the multi-tube fuel nozzle, and wherein a circumferential distance relative to the central axis between each mixing tube of the plurality of mixing tubes in each respective row of the plurality of rows is equal, a radial distance relative to the central axis between each mixing tube of the plurality of mixing tubes in each respective row of the plurality of rows is equal, and clearances between respective air entry regions of adjacent mixing tubes of the plurality of mixing tubes is equal.

10. A system for injecting fuel, comprising:
an end cover assembly and a multi-tube fuel nozzle, the multi-tube fuel nozzle comprising:
a retainer plate; and
a plurality of mixing tubes disposed between the end cover assembly and the retainer plate wherein the retainer plate is disposed about each downstream end of each mixing tube of the plurality of mixing tubes, and wherein each mixing tube comprises:
an annular wall disposed about a central passage, wherein the central passage extends from an upstream end of the annular wall adjacent the end cover assembly to a downstream end of the annular wall adjacent the retainer plate; and
an air inlet region configured to be disposed about a fuel injector extending into the central passage, wherein the air inlet region comprises an air entry surface comprising a bell-shaped portion of the annular wall;

wherein an outer diameter of each mixing tube initially increases from the upstream end prior to the bell-shaped portion and then continuously decreases through the bell-shaped portion in the direction of flow toward the downstream end, and an inner diameter of each mixing tube initially decreases from the upstream end prior to the bell-shaped portion and then remains constant in the direction of flow toward the downstream end of the annular wall.

11. The system of claim 10 , wherein each mixing tube of the plurality of mixing tubes is configured to be individually removed from or installed between the end cover assembly and the retainer plate.

12. The system of claim 11 , wherein the retainer plate is configured to be removed from the multi-tube fuel nozzle by sliding the retainer plate along the plurality of mixing tubes from the upstream end to the downstream end.

13. The system of claim 10 , wherein the air entry surface of each of the mixing tubes comprises an outer surface of the annular wall that gradually decreases in diameter in the direction of flow.

14. The system of 10 , wherein the air entry surface of each of the mixing tubes comprises an inner surface that gradually decreases in diameter in the direction of flow.

15. The system of claim 14 , wherein a cross-sectional area within the inner surface of each air inlet region increases adjacent a region of fuel injection from the fuel injector.

16. The system of claim 10 , wherein the bell-shaped portion of the air entry surface of each of the tubes comprises a contoured outer surface, a contoured inner surface, and a contoured turn portion disposed between the contoured outer surface and the contoured inner surface.

17. The system of claim 10 , wherein the plurality of mixing tubes comprises at least 50 mixing tubes.

18. A system for injecting fuel, comprising:
an end cover assembly and a multi-tube fuel nozzle, the multi-tube fuel nozzle comprising:
a retainer plate; and
a plurality of tubes disposed between the end cover assembly and the retainer plate, wherein the retainer plate is disposed about a downstream end of each of the plurality of tubes, wherein the plurality of tubes is arranged concentrically in a plurality of rows about a central axis of the multi-tube fuel nozzle, wherein a circumferential distance relative to the central axis between each tube of the plurality of tubes in each respective row of the plurality of rows is equal, a radial distance relative to the central axis between each tube of the plurality of tubes in each respective row of the plurality of rows is equal, and clearances between respective air entry regions of adjacent tubes of the plurality of mixing tubes is equal, and wherein each tube of the plurality of tubes comprises:
an annular wall disposed about a central passage, wherein the central passage extends from an upstream end of the annular wall adjacent the end cover assembly to a downstream end of the annular wall adjacent the retainer plate,
an air inlet region configured to be disposed about a fuel injector extending into the central passage, wherein the air inlet region comprises an air entry surface comprising a bell-shaped portion of the annular wall;
wherein an outer diameter of each mixing tube initially increases from the upstream end prior to the bell-shaped portion and then continuously decreases through the bell-shaped portion in the direction of flow toward the downstream end, and an inner diameter of each mixing tube initially decreases from the upstream end prior to the bell-shaped portion and then remains constant in the direction of flow toward the downstream end of t

Assignees

• Gen Electric

Inventors

• Chila Ronald James
• Melton Patrick Benedict
• Boardman Gregory Allen
• Westmoreland James Harold

Classifications

• F23D14/62

  Mixing devices; Mixing tubes · CPC title

• F23R3/286 Primary

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

• Y02T50/675

  Cross-Sectional Technologies · mapped topic

• F23R3/10

  for primary air (F23R3/06, F23R3/045 take precedence) · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title