Staged fuel and air injectors in combustion systems of gas turbines

Patent metadata

Field	Value
Publication number	US-10436450-B2
Application number	US-201615071090-A
Country	US
Kind code	B2
Filing date	Mar 15, 2016
Priority date	Mar 15, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

A staged injector in a combustor of a gas turbine. The staged injector may include an injector tube comprising a lateral wall enclosing an injection passageway that extends between an outlet and inlet. An outboard segment of the injector tube may include an exterior face. A cover may be formed about the outboard segment so form a surrounding plenum. The cover may include a side wall that radially overlaps the outboard segment and forms a first portion of the surrounding plenum therebetween. A ceiling wall of the cover may form a second portion of the surrounding plenum. A screening plate may be formed within the side wall of the cover that includes a multitude of apertures configured to fluidly connect the first portion of the surrounding plenum with a feed cavity formed exterior to the side wall.

First claim

That which is claimed:

1. A staged injector in a combustor of a gas turbine, wherein the combustor includes an inner radial wall defining a combustion zone downstream of a forward nozzle, the staged injector comprising:
an injector tube comprising a lateral wall enclosing an injection passageway that extends between an outlet and an inlet, wherein:
the outlet fluidly connects the injection passageway to the combustion zone;
the inlet is positioned outboard of the outlet such that the injection passageway comprises an injection angle;

a cover formed about an outboard segment of the injector tube so to enclose the outboard segment within a surrounding plenum, wherein the cover further includes:
a side wall that radially overlaps and encircles the outboard segment of the injector tube thereby forming a first portion of the surrounding plenum therebetween; and
a ceiling wall spanning between an outboard edge of the side wall so to form a second portion of the surrounding plenum that is outboard of the inlet of the injector tube; and

a screening plate formed within the side wall of the cover that includes a multitude of apertures configured to fluidly connect the first portion of the surrounding plenum with a feed cavity formed exterior to the side wall, the screening plate comprising a radially defined section of the side wall of the cover that extends circumferentially around at least a majority of a circumference of the sidewall:

wherein:
the lateral wall of the outboard segment comprises an interior face, which defines a portion of the injection passageway, and an exterior face, which defines a circumference of the outboard segment;
between the interior face and the exterior face, the outboard segment of the injector tube comprises a fuel plenum that encircles the injection passageway: and
the interior face of the injector tube comprises fuel ports fluidly connected to the fuel plenum.

2. The staged injector according to claim 1 , wherein the staged injector comprises a fuel and air injector axially staged downstream of the forward nozzle, the staged injector being describable according to orientation characteristics of the combustor, which include:
relative radial, axial, and circumferential positioning defined pursuant to a central axis of the combustor that extends longitudinally through the combustion zone defined within the inner radial wall;
a forward direction and an aftward direction defined relative to a forward end of the combustor defined by a head end and an aftward end of the combustor defined by a connection made with a turbine; and
a flow direction defined relative to an expected direction of flow within a specified conduit during operation of the gas turbine.

3. The staged injector according to claim 2 , wherein the outboard segment comprises a longitudinally defined segment of the injector tube that to one side borders the inlet of the injector tube;
wherein the ceiling wall of the cover comprise a continuous wall that fluidly isolates the second portion of the surrounding plenum from a region exterior to the surrounding plenum; and
wherein, along an inboard side, the surrounding plenum is bound by a floor wall, the floor wall opposing the ceiling wall across the surrounding plenum.

4. The staged injector according to claim 3 , wherein the radially defined section of the side wall extends circumferentially around at least three-quarters (0.75) of the circumference of the side wall.

5. The staged injector according to claim 3 , wherein the radially defined section of the side wall extends circumferentially around an entirety of the circumference of the side wall.

6. The staged injector according to claim 3 , wherein the combustor comprises an outer radial wall, the outer radial wall being formed about the inner radial wall such that a flow annulus is formed therebetween;
wherein a compressor discharge cavity is formed about the outer radial wall; and
wherein the screening plate comprises between 50 and 300 apertures.

7. The staged injector according to claim 6 , wherein an inboard boundary of the side wall is defined coplanar to the floor wall and an outboard boundary of the side wall is defined coplanar to the inlet of the injector tube;
wherein the radially defined section of the sidewall comprises a substantially constant radial offset from both the inboard boundary and the outboard boundary of the side wall;
wherein the injector tube comprises a cylindrical configuration;
wherein the screening plate comprises a cylindrical configuration that is concentrically arranged about the injector tube; and
wherein each of the multitude of apertures are configured to extend through a thickness of the screening plate along a path that is approximately perpendicular to an outer surface of the screening plate that surrounds each of the multitude of apertures.

8. The staged injector according to claim 6 , wherein the multitude of apertures are arranged in multiple circumferential extending, radially stacked rows that extend about the circumference of the side wall;
wherein the multitude of apertures comprise a circular cross-sectional shape; and
wherein the multitude of apertures are arranged in a tightly packed configured according to a hexagonal packing scheme in which the apertures in neighboring rows at least partially overlap.

9. The staged injector according to claim 6 , wherein an axis along which each of the multitude of apertures extends through the screening plate comprises an orientation such that each of the multitude of apertures is trained upon an area of the exterior face of the outboard segment that directly opposes another aperture of the multitude of apertures across the first portion of the surrounding plenum.

10. The staged injector according to claim 6 , wherein each aperture of the multitude of apertures of the screening plate comprises a substantially same cross-sectional flow area.

11. The staged injector according to claim 6 , wherein the multitude of apertures of the screening plate are configured having cross-sectional flow areas that vary between at least a first region and second region of the screening plate, and wherein a variation in cross-sectional flow areas is based on a desired flow characteristic within the surrounding plenum.

12. The staged injector according to claim 11 , wherein the desired flow characteristic is one that relates to an equal rate of airflow ingestion between the first region and the second region.

13. The staged injector according to claim 12 , wherein the cross-sectional flow areas between the first area and the second area are varied according to an expected pressure differential between the first region and the second region;
wherein the expected pressure differential comprises the first region having a higher pressure than the second region; and
wherein the variation of the cross-sectional flow areas comprises the first region having smaller cross-sectional flow areas than that of the second region.

14. The staged injector according to claim 6 , wherein the cover comprises an opening formed through a center of the ceiling wall configured for engagement by a bolt that extends therethrough for attaching the cover to the staged injector.

15. The staged injector according to claim 6 , wherein the floor wall resides approximately coplanar with the outer radial wall of the combustor; and
wherein the feed cavity comprises the compressor discharge cavity formed about the outer radial wall of the combustor.

16. The staged injector according to claim 6 , wherein the floor wall and the screening plate r

Assignees

• Gen Electric

Inventors

• Crawley Carolyn Ashley
• Cihlar David William
• Cai Jun

Classifications

• F23R3/286 Primary

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

• F23R3/14

  by using swirl vanes · CPC title

• F23R2900/03044

  Impingement cooled combustion chamber walls or subassemblies · CPC title

• F23R3/28

  characterised by the fuel supply (burners F23D) · CPC title

• F23R3/346 Primary

  for staged combustion · CPC title