Dual bayonet engagement and method of assembling a combustor liner in a gas turbine engine

Abstract

A combustor assembly is provided that includes a forward annular liner, an aft annular liner, and a stator. The forward annular liner has an inner annular edge and an outer annular edge. The aft annular liner is spaced apart from the forward annular liner to form a combustion chamber. The aft annular liner has an inner annular edge and an outer annular edge. The stator has a forward end and an aft end. The stator forward end includes an inner annular edge and an outer annular edge. The stator forward end inner annular edge is coupled to the aft annular liner outer annular edge via a first bayonet mount system, and the stator forward end outer annular edge is coupled to the forward annular liner outer annular edge via a second bayonet mount system.

Description

TECHNICAL FIELD

The present invention relates to a gas turbine engine and, more particularly, to a system for assembling a combustor liner.

BACKGROUND

In many aircraft, the main propulsion engines not only provide propulsion for the aircraft, but may also be used to drive various other rotating components such as, for example, generators, compressors, and pumps, which supply electrical and/or pneumatic power to the aircraft. However, when an aircraft is on the ground, its main engines may not be operating. Moreover, in some instances the main propulsion engines may not be capable of supplying the power needed for propulsion as well as the power to drive these other rotating components. Thus, many aircraft include one or more auxiliary power units (APUs) to supplement the main propulsion engines in providing electrical and/or pneumatic power. An APU may also be used to start the propulsion engines.

An APU is, in most instances, a gas turbine engine that includes a combustion system, a power turbine, and a compressor. During operation of the APU, the compressor draws in ambient air, compresses it, and supplies compressed air to the combustion system. The combustion system receives fuel from a fuel source and the compressed air from the compressor, and supplies high-energy combusted air to the power turbine, causing it to rotate. The power turbine includes a shaft that may be used to drive a generator for supplying electrical power, and to drive its own compressor and/or an external load compressor.

In some engine configurations, the combustion system is implemented with a rotary slinger combustor that uses a rotary fuel slinger to inject a continuous sheet of fuel into an annular combustor. Rotary slinger combustor systems have fewer components (i.e., they do not use fuel nozzles or have associated manifold components), however, they remain relatively cumbersome and time-consuming to assemble. In particular, these configurations still typically include numerous other components, such as numerous thermal springs, pins, and fasteners, that are sometimes assembled “blindly.” Specifically, the alignment of each component is not predetermined, and the system components may need to be individually aligned during an assembly process and additional tools and methods may need to be used. Consequently, the difficulty of assembling the systems and the cost of the assembled systems may be relatively high.

Hence, there is a need for a combustion system that includes a rotary slinger combustor that is relatively simple to install. It is also desirable for the system to include few parts. Moreover, it is desirable for the system to be relatively inexpensive to fabricate.

BRIEF SUMMARY

The present invention provides a combustor assembly. In one embodiment, and by way of example only, the combustor assembly includes a forward annular liner, an aft annular liner, and a stator. The forward annular liner has an inner annular edge and an outer annular edge. The aft annular liner is spaced apart from the forward annular liner to form a combustion chamber. The aft annular liner has an inner annular edge and an outer annular edge. The stator has a forward end including an inner annular edge and an outer annular edge. The stator forward end inner annular edge is coupled to the aft annular liner outer annular edge via a first bayonet mount system, and the stator forward end outer annular edge is coupled to the forward annular liner outer annular edge via a second bayonet mount system.

In another embodiment, and by way of example only, a combustor assembly kit for implementation into a combustor system is provided. The kit includes forward annular liner, an aft annular liner, and a stator. The forward annular liner has an inner annular edge and an outer annular edge. The aft annular liner is configured to be spaced apart from the forward annular liner to form a combustion chamber. The aft annular liner has an inner annular edge and an outer annular edge. The stator has a forward end including an inner annular edge and an outer annular edge. The stator forward end inner annular edge is configured to couple to the aft annular liner outer annular edge via a first bayonet mount system, and the stator forward end outer annular edge is configured to couple to the forward annular liner outer annular edge via a second bayonet mount system.

In still another embodiment, by way of example only, a method for assembling a combustor assembly is provided. The method includes the steps of attaching a first bayonet engagement surface of a first bayonet mount system to a second bayonet engagement surface of the first bayonet mount system, the first bayonet engagement surface formed on an outer annular edge of an aft annular liner, and the second bayonet engagement surface formed on a stator forward end inner annular edge, and engaging a first bayonet engagement surface of a second bayonet mount system with a second bayonet engagement surface of the second bayonet mount system, the first bayonet engagement surface formed on outer annular edge of an forward annular liner, and the second bayonet engagement surface formed on a stator forward end outer annular edge.

Other independent features and advantages of the preferred system will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section view of a portion of an auxiliary power unit according to an exemplary embodiment of the present invention;

FIG. 2 is a close up view of an exemplary combustion system that is used in the auxiliary power unit of FIG. 1;

FIG. 3 is a perspective view of an exemplary forward liner and an exemplary aft liner assembly that may be implemented into the combustor system shown in FIG. 2;

FIG. 4 is an exploded view of the aft liner assembly shown in FIG. 3;

FIG. 5 is a simplified cross section view of a portion of an exemplary assembled compressor section that may be implemented into the auxiliary power unit shown in FIG. 1;

FIG. 6 is a simplified cross section view of the compressor section with an exemplary forward liner coupled thereto; and

FIG. 7 is a perspective view of a portion of an exemplary assembled combustor section.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention.

Turning now to the description and with reference to FIG. 1, a cross section view of a portion of an exemplary assembled auxiliary power unit (APU) is shown. The APU 100 includes a compressor 102, a combustion system 104, and a turbine 106, all disposed within a case 110. Air is directed into the compressor 102 via an air inlet 112. The compressor 102 raises the pressure of air and supplies compressed air via a diffuser 114. In the depicted embodiment, the compressor 102 is a single-stage, high-pressure ratio centrifugal compressor. However, it will be appreciated that this is merely exemplary of a preferred embodiment, and that other types of compressors could also be used.

The compressed air from the compressor 102 is directed into the combustion system 104, where it is mixed with fuel supplied from a fuel source (not shown). In the combustion system 104 the fuel/air mixture is combusted, generating high-energy gas. The high-energy gas is then diluted and supplied to the turbine 106. A more detailed description of the combustion system 104, and the various components that provide this functionality, is provided further below.

The high-energy, diluted gas from the combustion system 104 expands through the turbine 106, where it gives up much of its energy and causes the turbine 106 to rotate. The gas is then exhausted from the APU 100 via an exhaust gas outlet 116. As the turbine 106 rotates, it drives, via a turbine shaft 118, various types of equipment that may be mounted in, or coupled to, the engine 100. For example, in the depicted embodiment the turbine 106 drives the compressor 102. It will be appreciated that the turbine may also be used to drive a generator and/or a load compressor and/or other rotational equipment, which are not shown in FIG. 1 for ease of illustration.

Turning now to FIG. 2, a close up view of the assembled combustion system 104 is illustrated. The combustion system 104 includes a combustor 202, a fuel supply tube 204, a rotary fuel slinger 206, and an igniter 208. The combustor 202 is a radial-annular combustor, and includes a forward annular liner 210, and an aft annular liner 212. The forward and aft annular liners 210, 212 are spaced apart from one another and form a combustion chamber 214. The forward and aft annular liners 210, 212 each include a plurality of air inlet orifices 216 (only some of which are shown), and a plurality of effusion cooling holes (not illustrated). As illustrated via the flow arrows in FIG. 2, compressed air 218 from the compressor 102 flows into the combustion chamber 214 via the air inlet orifices 216 in both the forward and aft annular liners 210, 212.

The fuel supply tube 204, which is preferably a steel tube, extends into a plenum 222 just forward of the combustor 202 and is adapted to receive a flow of fuel from a non-illustrated fuel source. The fuel supply tube 204 is preferably routed through the plenum 222, and is preferably configured with sufficient flexibility, to allow for any thermal mismatches that may occur between other components and systems in the APU 100 during operation. The fuel supplied to the fuel supply tube 204 passes through the tube 204, and is directed into a fuel housing 224. In the depicted embodiment, the fuel housing 224 is configured as a circumferential cavity, though it will be appreciated that other configurations could also be used. The fuel housing 224 includes a plurality of equally spaced holes 226 (only one of which is shown), through which the fuel is jetted to the rotary fuel slinger 206.

The rotary fuel slinger 206 includes a coupler shaft 228, a vertical shoulder 230, and a slinger 232. The coupler shaft 228 is coupled to the turbine shaft 118 (shown in FIG. 1) and rotates therewith. The vertical shoulder 230 is coupled to, and is preferably formed as an integral part of, the coupler shaft 228 and thus rotates with the coupler shaft 228. The fuel that is jetted through the holes 226 in the fuel housing 224 impinges onto the vertical shoulder 230. Because the vertical shoulder 230 rotates with the coupler shaft 228, the impinging fuel acquires the tangential velocity of the coupler shaft 228 and gets centrifuged into the slinger 232.

The slinger 232 is coupled to, and is preferably formed as an integral part of, the vertical shoulder 230 and thus also rotates with the coupler shaft 228. In the depicted embodiment, the slinger 232 has a substantially cup-shaped radial cross section, and includes a plurality of relatively small, equally spaced holes or slots 234. As the slinger 232 rotates, fuel is centrifuged through these holes 234, which atomize the fuel into tiny droplets and evenly distributes the fuel into the combustion chamber 214. The evenly distributed fuel droplets are readily evaporated and ignited in the combustion chamber 214.

The igniter 208 extends through the aft annular liner 212 and partially into the combustion chamber 214. The igniter 208, which may be any one of numerous types of igniters, is adapted to receive energy from an exciter (not shown) in response to the exciter receiving an ignition command from an external source, such as an engine controller (not illustrated). In response to the ignition command, the igniter 208 generates a spark of suitable energy, which ignites the fuel-air mixture in the combustion chamber 214, and generates the high-energy combusted gas that is supplied to the turbine 106.

The high-energy combusted gas is supplied from the combustor 202 to the turbine 106 via a turbine inlet nozzle 236 which then directs the air to a turbine. In this embodiment, the turbine is a two stage turbine and includes two sets of turbine rotors 238 disposed on either side of a second turbine nozzle 240. As the high-energy combusted air passes through the nozzles 236, 240 and impinges on the rotors 238, the rotors 238 rotate, which in turn causes the turbine shaft 118 to rotate, which in turn rotates the various other equipment that is coupled to the turbine shaft 118.

The combustor system 104 is assembled into the APU 100 in sections. Specifically, as depicted in FIG. 3, the combustor system 104 includes two major sections, namely, the forward annular liner 210 and an aft liner assembly 400 that are coupled to each other via a dual bayonet mounting system and mounted to the compressor 102. Each of these sections will now be discussed in more detail.

As shown in FIGS. 2 and 3, the forward annular liner 210 includes an outer surface 302, an inner annular edge 304, and an outer annular edge 306. The inner annular edge 304 includes an annular flange 305 formed proximate thereto extending radially inwardly therefrom that is configured to couple the forward annular liner 210 to the fuel housing 224. In one exemplary embodiment, the flange 305 is axially clamped to an annular flange 225 that extends radially outwardly from the fuel housing 224. The flanges 305, 225 may be coupled together via a threaded ring nut 307, or alternatively may be coupled together via any other type of mechanically constructed joint such as a bayonet type fastener. The outer annular edge 306 includes an annular flange 309 extending radially inwardly therefrom. The annular flange 309 includes a bayonet engagement surface 310 formed thereon, and both are configured to mate with a corresponding bayonet engagement surface 430 formed on a portion of the aft liner assembly 400 that will be discussed in more detail below.

With reference to FIGS. 2 and 4, the aft liner assembly 400 is a subassembly that includes the aft annular liner 212, a turbine stator 402, a labyrinth seal component 404, and a flow discourager 406. The aft annular liner 212 has an inner annular edge 408, an outer annular edge 410, and an igniter opening 412 (shown in FIG. 2). As briefly alluded to above, the inner annular edge 408 includes an inner annular flange 409 extending radially inwardly therefrom that couples the aft annular liner 212 to the labyrinth seal component 404. In one exemplary embodiment, the annular flange 409 and the aft annular liner 212 are axially clamped. Specifically, the annular flange 409 is clamped to the forward end 442 of the labyrinth seal component 404 via a threaded ring nut 413 or any other type of mechanically constructed joint such as a bayonet type fastener. The outer annular edge 410 preferably includes a bayonet engagement surface 414 formed thereon and is configured to mate with a corresponding bayonet engagement surface 416 formed on the stator 402.

The stator 402 includes a forward end 418 and an aft end 420 that each includes inner annular edges 422, 424, respectively, and outer annular edges 426, 428, respectively. The forward end inner and outer annular edges 422, 426 each include a bayonet engagement surface 416, 430, respectively. The bayonet engagement surface 416 of the forward end inner annular edge 422, as mentioned above, is configured to mate with the bayonet engagement surface 414 of the aft annular liner 212. The bayonet engagement surface 430 of the forward end outer annular edge 426 is configured to mate with the bayonet engagement surface 310 of the forward annular liner 210. The aft end 420 includes an inner radial flange 434 and an outer radial flange 436 that are each configured to couple other components to the stator 402.

The labyrinth seal component 404 is configured to surround and extend along at least a portion of the shaft 118 and includes seals 440 (shown in FIG. 2) disposed thereon. It will be appreciated that although two seals 440 are shown, the labyrinth seal component 404 may have fewer or more seals 440 disposed thereon. Moreover, although labyrinth seals are used in this embodiment, any other suitable type of seal may alternatively be used. In any case, the labyrinth seal component 404 includes a forward end 442 and an aft end 444. As briefly mentioned above, the forward end 442 is coupled to the inner annular flange 409 of the aft annular liner 212 and using any one of numerous suitable techniques. For example, the forward end 442 and flange 413 may be bolted, threadingly fastened, or otherwise coupled together, such as by, for example, the ring nut 413. The aft end 444 of the labyrinth seal component 404 is coupled to the inner radial flange 434 of the stator 402 and the flow discourager 406 via a plurality of bolts

During an APU 100 assembly process, the compressor 102 is preferably first assembled in a conventional manner. FIG. 5 illustrates an exemplary assembled compressor 102 that includes a compressor housing 500, diffuser 502, deswirl assembly 504, shaft 118, and the fuel line 204. The diffuser 502 and deswirl assembly 504 are mounted to the compressor housing 500, which includes an opening 510 through which the fuel line 204 extends. A compressor back shroud 512 is disposed between the shaft 118 and fuel line 204. The fuel housing 224 is joined to the compressor back shroud 512 by via a plurality of bolts and includes an opening 514 formed therein and a combustor liner holding flange 516 extending therefrom. The combustor liner holding flange 516 includes a fastening surface 518, such as threading, formed thereon.

After the compressor 102 is assembled, the combustor system 104 is mounted to the compressor 102. First, the forward annular liner 210 is mounted to the combustor liner holding flange 516. For example, the forward annular liner 210 is threadingly coupled to the fastening surface 518. Additionally, the rotary fuel slinger 206 is inserted into an appropriate location on the shaft 118 engaging the compressor 102 to form a subassembly 600, a portion of which is shown in FIG. 6. Specifically, an end of the coupler shaft 228 is inserted into the forward annular liner 210 and mounted thereto such that the slinger 232 is proximate the fuel line holes 226 and the slinger holes 234 are disposed aft of the forward annular liner inner annular edge 304.

Next, the aft liner assembly 400 is mounted onto the subassembly 600. The aft liner assembly 400 is preferably preassembled prior to being mounted on to the subassembly 600. In this regard, the aft annular liner 212, stator 402, labyrinth seal component 404 and flow discourager 406 are attached to one another. The inner annular edge 408 of the aft annular liner 212, in particular, the annular flange 409, and the forward end 442 of the labyrinth seal component 404 are engaged with each other. The aft annular liner 212 and labyrinth seal component 404 are then coupled to the stator 402 via a first bayonet mount system. Specifically, the bayonet engagement surface 414 of the outer annular edge 410 of the aft liner 212 is mated with the corresponding bayonet engagement surface 416 of the stator 402.

Once the first bayonet mount system is properly engaged, the labyrinth seal component 404 may be axially adjusted so that its aft end 444 couples to the stator inner radial flange 420. To do so, the labyrinth seal component end 444, stator inner radial flange 420 and flow discourager 406 may be bolted or otherwise coupled together.

When the aft liner subassembly 400 is assembled, it is coupled to the subassembly 600 and forward annular liner 210 via a second bayonet mount system. In particular, the bayonet engagement surface 430 of the stator forward end outer annular edge 426 is engaged with the bayonet engagement surface 310 of the forward annular liner 210. An annular axially spaced gap 308 (see FIG. 2) is formed between the aft and forward annular liners 210, 212 that is preferably aligned with the slinger holes 234.

The remainder of the APU 100 is assembled in a conventional manner. For example, as shown in FIG. 7, a containment ring 702 is preferably fastened to the stator outer radial flange 422, via a bolt or other conventional fastening mechanism. Then, as shown in FIG. 1, the igniter 208 is appropriately coupled to the igniter opening 412, the turbine section 106 is assembled and coupled to the containment ring 702 in a conventional manner, and a combustor housing 704 is inserted and assembled into an aft frame housing 706.

There has now been provided a combustion system that includes a rotary slinger combustor that is relatively simple to install. The system also includes fewer components than previous-known combustion systems. Moreover, the system is relatively inexpensive to fabricate and may be retrofitted into existing engines.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A combustor assembly comprising:

a forward annular liner having an inner annular edge and an outer annular edge;

an aft annular liner spaced apart from the forward annular liner to form a combustion chamber, the aft annular liner having an inner annular edge and an outer annular edge; and

a stator having a forward end including an inner annular edge and an outer annular edge, the stator forward end inner annular edge coupled to the aft annular liner outer annular edge via a first bayonet mount system, and the stator forward end outer annular edge coupled to the forward annular liner outer annular edge via a second bayonet mount system.

2. The assembly of claim 1, wherein the first bayonet mount system includes a first and a second bayonet engagement face, the first bayonet engagement face formed on the aft annular liner outer annular edge and the second bayonet engagement face formed on the stator forward end inner annular edge.

3. The assembly of claim 2, wherein the second bayonet mount system includes a first and a second bayonet engagement face, the first bayonet engagement face formed on the forward annular liner outer annular edge and the second bayonet engagement face formed on the stator forward end outer annular edge.

4. The assembly of claim 1, wherein the aft annular liner inner annular edge is proximate to the forward annular liner inner annular edge and the system further comprises:

an annular gap formed between the aft annular liner and the forward annular liner.

5. The assembly of claim 4, further comprising a slinger coupled to the shaft, the slinger including a plurality of holes formed therein that communicate with the annular gap.

6. The assembly of claim 1, wherein the stator includes an aft end, the aft annular liner assembly further comprises a labyrinth seal component extending axially relative to the shaft including a forward end and an aft end, and the labyrinth seal component forward end coupled to the aft annular liner inner annular edge and the labyrinth seal aft end coupled to the stator aft end.

7. The assembly of claim 6, wherein the labyrinth seal component includes a first and a second labyrinth seal coupled thereto.

8. The assembly of claim 6, further comprising a flow discourager coupled to the labyrinth seal aft end.

9. A combustor assembly kit for implementation into a combustor system, comprising:

a forward annular liner having an inner annular edge and an outer annular edge;

an aft annular liner configured to be spaced apart from the forward annular liner to form a combustion chamber, the aft annular liner having an inner annular edge and an outer annular edge; and

a stator having a forward end including an inner annular edge and an outer annular edge, the stator forward end inner annular edge configured to be coupled to the aft annular liner outer annular edge via a first bayonet mount system, and the stator forward end outer annular edge configured to be coupled to the forward annular liner outer annular edge via a second bayonet mount system.

10. The kit of claim 9, wherein the stator includes an aft end and the kit further comprises a labyrinth seal component configured to extend axially along and to be disposed about a shaft, the labyrinth seal component including a forward end and an aft end, the labyrinth seal component forward end configured to couple to the aft annular liner inner annular edge and the labyrinth seal component aft end configured to couple to the stator aft end.

11. The kit of claim 10, further comprising a flow discourager configured to couple to the labyrinth seal component aft end.

12. The kit of claim 9, wherein the forward annular liner and aft liner are configured to form an annular gap therebetween.

13. The kit of claim 12, further comprising a slinger configured to couple to a shaft, the slinger including a plurality of openings formed therein that are configured to communicate with the annular gap.

14. A method for assembling a combustor assembly, comprising:

attaching a first bayonet engagement surface of a first bayonet mount system to a second bayonet engagement surface of the first bayonet mount system, the first bayonet engagement surface formed on an outer annular edge of an aft annular liner, and the second bayonet engagement surface formed on an inner annular edge of a stator forward end; and

engaging a first bayonet engagement surface of a second bayonet mount system with a second bayonet engagement surface of the second bayonet mount system, the first bayonet engagement surface formed on outer annular edge of an forward annular liner, and the second bayonet engagement surface formed on an outer annular edge of the stator forward end.

15. The method of claim 14, further comprising:

threading a threaded first end of a labyrinth seal to a threaded inner annular edge of the aft annular liner and axially adjusting the labyrinth seal to mate with at least a portion of a stator aft end, before the step of engaging the first bayonet engagement surface.

16. The method of claim 15, further comprising:

coupling a flow discourager to at least a portion of the labyrinth seal, before the step of engaging the first bayonet engagement surface.

17. The method of claim 14, wherein a shaft extends at least partially through the combustor system and the method further comprises the steps of:

mounting a slinger to the shaft, the slinger having an annular fuel opening formed therein; and

aligning the slinger fuel opening with an annular gap formed between the forward annular liner and the aft annular liner.

18. The method of claim 14, further comprising:

fastening a containment ring to the stator.

19. The method of claim 14, further comprising:

coupling the forward annular liner to a compressor section.

20. The method of claim 19, wherein the step of coupling comprises mounting a portion of the forward annular liner inner annular edge to a forward support housing coupled to a compressor housing of the compressor section.