Patent Grant
7062920
The present invention relates generally to a combustor dome assembly for a gas turbine engine and, in particular, to a combustor dome assembly having a plurality of free floating swirlers which are retained in position between the dome plate and the inner and outer cowls so that each swirler is able to receive a fuel nozzle and be movable radially and axially in conjunction therewith.
It is well known within the combustor art of gas turbine engines that a dome portion, in conjunction with inner and outer liners, serves to form the boundary of a combustion chamber. A mixture of fuel and air is ignited and burned in such combustion chamber so that the products thereof are able to interface with the blades of turbines and produce work through one or more shafts. The annular combustor dome also serves to position a plurality of mixers in a circumferential manner so that a fuel/air mixture is provided to the combustion chamber in a desired manner.
Gas turbine combustors typically require a floating ferrule or primary swirler to prevent air leakage into the combustor and still allow for thermal growths of the combustor, combustion casing and fuel nozzles. This requirement has oftentimes been accomplished by brazing a secondary swirler or pad into the dome and using a welded retainer to hold the floating ferrule or primary swirler in place. It will be appreciated that the location of such components is critical to the combustor performance and functionality. Examples of such an arrangement are disclosed in U.S. Pat. No. 6,427,435 to Patterson et al. and U.S. Pat. No. 6,314,739 to Howell et al.
While the typical combustor arrangement has adequate space between swirler cups to incorporate features to enhance the spectacle plate structure (e.g., the addition of ribs, cooling holes and the like), certain geometric restrictions have been introduced by current combustor designs which run lean so as to minimize emissions. As disclosed in U.S. Pat. No. 6,381,964 to Pritchard, Jr. et al., one particular fuel/air mixer configuration includes a fuel nozzle which contains a pilot mixer therein. The fuel nozzle is then located within a main mixer. Accordingly, the size of the fuel nozzle and the corresponding swirler assembly associated therewith, has increased significantly from those previously utilized and thereby reduced the distance between adjacent swirler cups. Utilization of an annular dome plate having a greater diameter would serve to increase the weight of the engine and require modification of components interfacing therewith. Thus, the openings in the dome plate have been enlarged and thereby lessened the circumferential distance between adjacent openings.
Thus, in light of the foregoing, it would be desirable for a combustor dome assembly to be developed which accommodates minimum spacing between adjacent swirler cups. It would also be desirable to simplify such a combustor dome assembly and reduce the amount of components needed while maintaining its intended functionality. Improvements in the area of producibility, maintainability and serviceability are likewise desired.
In a first exemplary embodiment of the invention, a combustor dome assembly for a gas turbine engine is disclosed as having a longitudinal centerline axis extending therethrough. The combustor assembly includes: an annular dome plate having an inner portion, an outer portion, a forward surface and a plurality of circumferentially spaced openings formed therein, wherein a radial section is defined between adjacent openings; an annular outer cowl connected to the outer portion of the dome plate; an annular inner cowl connected to the inner portion of the dome plate; and, a swirler located between the forward surface of the dome plate and the inner and outer cowls in substantial alignment with each of the openings in the dome plate. Each swirler further includes a forward portion and an aft portion and is retained by at least one tab member located upstream thereof so as to be movable in a radial and axial direction.
In a second exemplary embodiment of the invention, an annular cowl for a gas turbine engine combustor having a longitudinal centerline axis therethrough is disclosed, where the combustor includes an annular dome plate having an inner portion, an outer portion, a forward surface and a plurality of circumferentially spaced openings formed therein. The cowl includes a downstream end connected to one of the inner and outer portions of the dome plate, an upstream end positioned upstream of the forward surface for the dome plate, and a plurality of circumferentially spaced tab members extending from an inner surface of the upstream end. The tab members serve to retain a corresponding swirler between the cowl and the dome plate in a free floating manner while maintaining substantial alignment with one of the openings in the dome plate.
Referring now to the drawings in detail, wherein identical numerals indicate the same elements throughout the figures,
More specifically, it will be understood that dome plate 20 is annular in configuration and includes an inner portion 30, an outer portion 32, a forward surface 34 and a plurality of circumferentially spaced openings 36 formed therein (see
Each swirler 26 is located between forward surface 34 of dome plate 20 and upstream ends 47 and 49 of outer and inner cowls 38 and 44, respectively, so as to be in substantial alignment with an opening 36 in dome plate 20. Further, each swirler 26 preferably includes a forward portion 50 and an aft portion 52. It will be appreciated that swirlers 26 are not fixed or attached to any other component of air/fuel mixer 22, but are permitted to float freely in both a radial and axial direction with respect to a centerline axis 53 through each opening 36. Each swirler 26 preferably includes vanes 48 therein which are oriented to provide swirl in a substantially radial direction with respect to centerline axis 53.
It is desirable, however, that swirlers 26 be retained in position between dome plate 20 and cowl upstream ends 47 and 49 so that fuel nozzles 24 may be desirably received therein. Accordingly, at least one tab member is provided upstream of each swirler 26 to restrict radial and axial movement thereof to a predetermined amount. Preferably, it will be noted that a first tab member 54 and a second tab member 56 are located upstream of each swirler 26 at approximately a radially outer position and a radially inner position, respectively. As seen in
As best seen in
Alternatively, as seen in
Swirler aft portion 52 preferably includes a flange 74 which is able to slide radially along a boss portion 75 of dome plate forward surface 34. A lip 76 is connected to flange 74 and is preferably oriented substantially perpendicular to flange 74 so that it is substantially parallel to centerline axis 53. It will be noted that lip 76 extends aft of dome plate forward surface 34 so that it interfaces with deflector plate 28 to limit radial movement of swirler aft portion 52.
Fuel nozzle 24 is preferably of the type disclosed in U.S. Pat. No. 6,381,964 to Pritchard, Jr. et al., which is hereby incorporated by reference. It will be appreciated that fuel nozzle 24 is larger than typical fuel nozzles and therefore requires larger openings in dome plate 20. It will be understood that one feature of free floating swirlers 26 is the ability to move with fuel nozzles 24 during operation of the gas turbine engine. Further, swirlers 26 are able to be adjusted when fuel nozzles 24 are inserted therein. In this regard, tab members 54 and 56 are configured to provide an adequate clearance with fuel nozzles 24.
Other advantages are also associated with the combustor dome assembly of the present invention. For example, producibility of the combustor dome assembly is improved since a braze and weld operation at each swirler is eliminated. Moreover, inspection of the braze joint connecting deflector plates 28 to dome plate 20 is enhanced. Since the number of components in the combustor dome assembly is reduced, maintainability of swirlers 26 is improved. Because swirlers 26 can be removed simply by unbolting one of cowls 38 or 44 via connectors 40 or 46, respectively, the time and effort required for performing maintenance and the like is reduced.
Having shown and described the preferred embodiment of the present invention, further adaptations of the combustor and the dome thereof can be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3703259 | Sturgess et al. | Nov 1972 | A |
| 4763482 | Wehner | Aug 1988 | A |
| 5865024 | Kress et al. | Feb 1999 | A |
| 5916142 | Snyder et al. | Jun 1999 | A |
| 6134877 | Alkabie | Oct 2000 | A |
| 6314739 | Howell et al. | Nov 2001 | B1 |
| 6363726 | Durbin et al. | Apr 2002 | B1 |
| 6381964 | Pritchard, Jr. et al. | May 2002 | B1 |
| 6418726 | Foust et al. | Jul 2002 | B1 |
| 6427435 | Patterson et al. | Aug 2002 | B1 |
| 6453671 | Leen et al. | Sep 2002 | B1 |
| 6484489 | Foust et al. | Nov 2002 | B1 |
| 6571559 | Fortuna et al. | Jun 2003 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20050034460 A1 | Feb 2005 | US |
