Combustion chamber interstage section structure, combustion chamber and aero-engine

Abstract

The invention provides a combustion chamber interstage section structure which is made of a ceramic matrix composite material and comprises a first annular structure, a second annular structure and a supporting ring face located between the first annular structure and the second annular structure. The metal switching section comprises a connecting piece and a baffle plate, and the connecting piece and the baffle plate are opposite to each other and define an annular groove for accommodating the second annular structure; the axial elastic sheet is arranged between the baffle and the interstage section and is positioned on the periphery of the supporting ring surface; the radial elastic piece is located in the annular groove and arranged on the radial outer side of the second annular structure. And the fastener is used for fastening the connecting piece and the baffle and enabling the connecting piece and the baffle to clamp the second annular structure. By means of the structure, the interstage section of the ceramic matrix composite can release thermal deformation in the axial direction and the radial direction in time, and thermal stress is reduced. A combustion chamber and an aero-engine are also provided.

Description

Technical Field

[0001] The present invention relates to the field of aero engines, and in particular to the field of combustion chamber CMC interstage sections. Background Art

[0002] With the development of aero-engine technology, the temperature before the engine turbine continues to increase, and the staged combustion technology is generally used in the combustion chamber head of modern aero-engines. The nozzle interstage section is located between the main combustion stage and the pre-combustion stage of the combustion chamber, and the heat load of the working environment will continue to increase. How to prevent the interstage section from ablation and enable it to serve safely for a long time is one of the main challenges in the design of aero-engine combustion chambers. The service life of the combustion chamber interstage section made of traditional high-temperature alloys or single crystals poses a great challenge. Even mature products will experience interstage ablation after long-term service. Interstage ablation will affect the safe use of the nozzle, so the interstage section also faces the problem of maintenance and replacement, so it is necessary to consider developing an interstage section structure with higher temperature resistance of ceramic matrix composites (Ceramic Matrix Composites, CMC).

[0003] Limited by the manufacturing process, CMC materials are currently mainly used for the inner and outer rings of the combustion chamber flame tube, turbine blades, etc., and cannot be used on a large scale. Due to the low linear expansion coefficient of CMC materials, attention should be paid to the design and coordination of the connection structure with other metal parts to avoid the different expansion amounts under hot conditions, which will lead to large internal stress and thus structural failure. In addition, the convenience of maintenance of the interstage section should also be considered. Summary of the invention

[0004] An object of the present invention is to provide a combustion chamber interstage structure having a better thermal deformation release effect.

[0005] To achieve the above-mentioned purpose, the combustion chamber interstage structure includes an interstage, a metal transition section, axial spring pieces, radial spring pieces and fasteners. The interstage is made of a ceramic-based composite material, and includes a first annular structure, a second annular structure and a supporting annular surface located between the first annular structure and the second annular structure; the metal transition section includes a connecting piece and a baffle, the connecting piece and the baffle facing each other, defining an annular groove for accommodating the second annular structure; the axial spring piece is arranged between the baffle and the interstage and located on the outer periphery of the supporting annular surface; the radial spring piece is located in the annular groove and arranged on the radial outside of the second annular structure; the fastener is used to fasten the connecting piece and the baffle, and enable the connecting piece and the baffle to clamp the second annular structure.

[0006] In one or more embodiments, the fastener is detachably connected to the connecting member and the baffle.

[0007] In one or more embodiments, the fastener passes through the axial spring sheet.

[0008] In one or more embodiments, the axial spring tabs include radial cooling holes.

[0009] In one or more embodiments, the connecting piece is provided with a first axial cooling hole.

[0010] In one or more embodiments, the first axial cooling holes include inner ring cooling holes facing the end surface of the second annular structure and impingement cooling holes facing the baffle.

[0011] In one or more embodiments, the baffle is provided with a second axial cooling hole aligned with the impingement cooling hole.

[0012] In one or more embodiments, the baffle includes two semicircular ring structures spliced ​​to each other.

[0013] In one or more embodiments, the axial spring pieces between the baffle and the interstage section are arranged to be in an axially pre-tightened state, and the radial spring pieces in the annular groove and radially outside the second annular structure are arranged to be in a radially pre-tightened state.

[0014] Another object of the present invention is to provide a combustion chamber, comprising a flame tube, a fuel nozzle, a main combustion stage swirler, and a pre-combustion stage swirler, wherein the flame tube defines a combustion space, a plurality of the main combustion stage swirlers are arranged around the pre-combustion stage swirler, and also comprises the above-mentioned combustion chamber interstage section structure, the connecting part of the combustion chamber interstage section structure is fixedly connected to the pre-combustion stage swirler, and the first annular structure faces the combustion space.

[0015] In one or more embodiments, the connecting piece is welded to the pre-combustion stage swirler.

[0016] Another object of the present invention is to provide an aircraft engine comprising the above-mentioned combustion chamber.

[0017] The above-mentioned interstage structure adopts the combination of radial spring fragment structure and axial spring fragment structure to ensure that the CMC interstage can achieve radial floating and axial floating at the same time, so that the CMC interstage can release thermal deformation, reduce thermal stress and improve service life. The damping effect brought by the radial spring fragment structure and the axial spring fragment structure can reduce the radial vibration and axial vibration of the CMC interstage during operation, thereby reducing the risk of vibration failure of the CMC interstage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0019] Figure 1 It is a schematic diagram of the structure of the combustion chamber of an aircraft engine;

[0020] Figure 2A It is a cross-sectional view of the interstage structure;

[0021] Figure 2B yes Figure 2A Enlarged view of point C in the middle;

[0022] Figure 3 It is a side view of the interstage structure;

[0023] Figure 4 It is a schematic diagram of the cooling holes of the transition section;

[0024] Figure 5 It is a schematic diagram of the disassembly of the components of the interstage structure. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0026] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0027] Figure 1 A simplified structural diagram of an aircraft engine combustion chamber is shown, and the aircraft engine combustion chamber includes a combustion chamber fuel nozzle 1, a pre-combustion stage swirler 3, a main combustion stage swirler 4, a flame tube 5, an interstage section 2, and an outer casing 6. The interstage section 2 is located outside the fuel nozzle 1, and is surrounded by two flames, namely, the premixed combustion formed downstream of the main combustion stage swirler 4 and the diffusion combustion formed downstream of the pre-combustion stage swirler 3. Therefore, there are generally problems such as high heat load and easy ablation, and there is great difficulty in thermal protection design.

[0028] Figures 2A to 5 The interstage structure of the present disclosure is shown, where X represents the axial direction and Y represents the radial direction. The interstage structure includes an interstage 23 made of a ceramic matrix composite material (CMC) and a metal transition section, and the metal transition section includes a connector 21 and a baffle 22 .

[0029] Reference Figure 5It is understood that the interstage 23 includes a first annular structure 231, a second annular structure 232 and a support annular surface 233 located between the first annular structure 231 and the second annular structure 232. Preferably, the first annular structure 231 faces the combustion zone, and the outer diameter of the second annular structure 232 is smaller than that of the first annular structure 231.

[0030] The connecting member 21 and the baffle plate 22 face each other, defining an annular groove 235 for accommodating the second annular structure 232. Figure 2B and Figure 5 In the illustrated embodiment, the annular groove 235 is provided on the inner annular surface of the baffle 22. Those skilled in the art will appreciate that, in other embodiments, the axial side groove surfaces of the annular groove 235 may be provided by the connector 21 and the baffle 22, respectively.

[0031] In order to enable the CMC interstage section to release thermal deformation, the interstage section structure disclosed in the present disclosure further includes axial spring clips 25 and radial spring clips 26 to ensure that the CMC interstage section can achieve radial floating and axial floating at the same time.

[0032] The axial spring piece 25 is arranged between the baffle 22 and the interstage 23 and is located at the outer periphery of the support annular surface 233 to ensure that the CMC interstage 23 can float axially. When assembling the axial spring piece 25, a certain axial preload should be preset to keep the axial spring piece 25 with a certain pressure in any working state, so as to achieve a better seal between the end surface 236 of the annular structure 232 and the annular groove 235.

[0033] The radial spring piece 26 is located in the annular groove 235 and is arranged radially outside the second annular structure 232 to ensure that the CMC interstage section 23 can float radially. When assembling the radial spring piece 26, a certain radial preload should be preset to maintain a certain pressure on the radial spring piece 26 in any working state, thereby achieving better sealing.

[0034] The fastener 24 is used to fasten the connector 21 and the baffle 22, and enables the connector 21 and the baffle 22 to clamp the second annular structure 232. For example, the fastener 24 is a mounting bolt, the mounting baffle 22 is provided with a threaded hole 221, and the transition section 21 is fastened and connected with the metal mounting baffle 22 by the mounting bolt.

[0035] In order to facilitate maintenance and replacement of the interstage section 23 , the fastener 24 detachably connects the connecting member 21 and the baffle 22 .

[0036] In some embodiments, after the mounting bolts connect the metal transition section 21 with the metal mounting baffle 22 , they extend into the preset connection hole 251 of the axial spring piece 25 to penetrate the axial spring piece 25 , and limit the axial spring piece 25 to prevent the axial spring piece 25 from falling off.

[0037] Furthermore, the damping effect brought by the radial spring pieces 26 and the axial spring pieces 25 can reduce the radial vibration and axial vibration of the CMC interstage section 23 during operation, thereby reducing the risk of vibration failure of the CMC interstage section 23 .

[0038] In some embodiments, the radial spring pieces 26 and the axial spring pieces 25 are made of high temperature alloy or stainless steel.

[0039] Continue to refer to Figure 3 and Figure 4 As shown, the transition section 21 is provided with a first axial cooling hole 211. Furthermore, the first axial cooling hole 211 includes an inner ring cooling hole 2112 for cooling the clamped position of the CMC interstage section 23 (i.e., the end face of the second annular structure 232) and an impingement cooling hole 2113 facing the baffle 22. Relatively speaking, the inner ring cooling hole 2112 is located radially inward, and the impingement cooling hole 2113 is located radially outward.

[0040] Specifically, the inner ring cooling holes 2112 are used to cool the end surface of the CMC interstage section 23 where it is clamped. Figure 2B The left end surface shown on one side of the gap 212 prevents high-temperature combustion gas from penetrating into the gap 212 between the mounting baffle 22 and the CMC interstage section 23. The inner ring cooling hole 2112 is beneficial to reducing the temperature at the connection position and ensuring the reliability of the connection structure.

[0041] The baffle 22 is also provided with a second axial cooling hole 222 aligned with the impingement cooling hole 2113, as shown in FIG. Figure 5 As shown, it is used to guide cold air to reduce the wall temperature of the CMC interstage section 23, thereby increasing the service life of the CMC interstage section 23.

[0042] Continue to refer to Figure 5 As shown, the axial spring piece 25 includes a radial cooling hole 252 for cooling the axial spring piece 25 to maintain the reliability of the axial spring piece 25 .

[0043] The metal baffle 22 is preferably divided into two semicircular ring structures spliced ​​to each other. During assembly, the radial spring piece 26 and the axial spring piece 25 are first placed at the corresponding connection position of the CMC interstage section 23, and then the two semicircular ring structures of the metal baffle 22 are engaged with the second annular structure 232 of the CMC interstage section 23. After adjusting the preload of the radial spring piece 26 and the axial spring piece 25, the two semicircular ring structures of the metal baffle 22 are closed, and the metal transition section 21 is connected to the metal baffle 22 through the threaded holes on the metal baffle 22 with multiple circumferential fasteners 24, such as mounting bolts, and then the mounting bolts are tightened to extend into the preset connection hole 251 of the axial spring piece 25. In this way, the connector 21 and the baffle 22 are fastened by the fastening action of the fastener 24, and the connector 21 and the baffle 22 clamp the second annular structure 232 of the interstage section 23.

[0044] Preferably, a small gap is provided between the axial tail end of the mounting bolt and the interstage section 23 to allow the interstage section 23 to float.

[0045] In some embodiments, the connection hole 251 can be set to a circular hole or an elliptical hole with a diameter larger than that of the fastener 24, so that the fastener can be aligned with the position of the connection hole 251 to improve assembly convenience.

[0046] In this way, when the interstage segment 23 needs to be repaired and replaced after long-term service, it is only necessary to loosen the fasteners 24, replace the processed or repaired interstage segment 23 and reassemble it without scrapping the entire segment, which greatly improves the convenience of repairing the interstage segment 23 and significantly reduces the repair time and cost.

[0047] The above combustion chamber interstage structure adopts a combination of radial spring fragment structure and axial spring fragment structure to ensure that the CMC interstage can achieve radial floating and axial floating at the same time, so that the CMC interstage can release thermal deformation, reduce thermal stress, and improve service life; the damping effect brought by the radial spring fragment structure and the axial spring fragment structure can also reduce the radial vibration and axial vibration of the CMC interstage when it is working, thereby reducing the risk of vibration failure of the CMC interstage. The radial spring fragment structure and the axial spring fragment structure can also achieve better sealing by presetting a certain preload.

[0048] In combination with the introduction to the above-mentioned interstage connection structure, a combustion chamber and an aircraft engine including the combustion chamber can also be understood.

[0049] The combustion chamber includes a flame tube 5, a fuel nozzle 1, a main combustion stage swirler 4, a pre-combustion stage swirler 3 and the above-mentioned combustion chamber interstage structure. The flame tube 5 defines a combustion space 501, and one or more main combustion stage swirlers 4 are arranged outside the pre-combustion stage swirler 3. Among them, the connecting piece 21 of the combustion chamber interstage structure is fixedly connected to the pre-combustion stage swirler 3, such as being directly welded to the pre-combustion stage swirler 3.

[0050] It should be noted that the above content uses words such as "first" and "second" to limit components, which is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0051] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0052] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. Combustion chamber interstage structure, characterized in that: include: The interstage section (23) is made of a ceramic-based composite material, and comprises a first annular structure (231), a second annular structure (232), and a supporting annular surface (233) located between the first annular structure (231) and the second annular structure (232); The metal transition section comprises a connecting piece (21) and a baffle (22), wherein the connecting piece (21) and the baffle (22) face each other and define an annular groove (235) for accommodating the second annular structure (232); An axial spring sheet (25) is arranged between the baffle (22) and the interstage section (23) and is located on the outer periphery of the supporting annular surface (233); A radial spring piece (26), located in the annular groove (235) and arranged radially outside the second annular structure (232); as well as A fastener (24) is used to fasten the connecting member (21) and the baffle (22), and enable the connecting member (21) and the baffle (22) to clamp the second annular structure (232).

2. The combustion chamber interstage structure according to claim 1, characterized in that: The fastener (24) is detachably connected to the connecting member (21) and the baffle (22).

3. The combustion chamber interstage structure according to claim 1, characterized in that: The fastener (24) passes through the axial spring sheet (25).

4. The combustion chamber interstage structure according to claim 1, characterized in that: The axial spring sheet (25) comprises radial cooling holes.

5. The combustion chamber interstage structure according to claim 1, characterized in that: The connecting piece (21) is provided with a first axial cooling hole (211).

6. The combustion chamber interstage structure according to claim 5, characterized in that: The first axial cooling hole (211) includes an inner ring cooling hole (2112) facing the end surface of the second annular structure (232) and an impact cooling hole (2113) facing the baffle (22).

7. The combustion chamber interstage structure according to claim 6, characterized in that: The baffle (22) is provided with a second axial cooling hole (222) aligned with the impingement cooling hole (2113).

8. The combustion chamber interstage structure according to claim 1, characterized in that: The baffle (22) comprises two semicircular ring structures spliced ​​to each other.

9. The combustion chamber interstage structure according to claim 1, characterized in that: The axial spring piece (25) located between the baffle (22) and the interstage section (23) is arranged to be in an axial pre-tightened state, and the radial spring piece (26) located in the annular groove (235) and radially outside the second annular structure (232) is arranged to be in a radial pre-tightened state.

10. A combustion chamber, comprising a flame tube, a fuel nozzle, a main combustion stage swirler, and a pre-combustion stage swirler, wherein the flame tube defines a combustion space, characterized in that: It also includes the combustion chamber interstage section structure according to any one of claims 1 to 9, wherein the connecting piece of the combustion chamber interstage section structure is fixedly connected to the pre-combustion stage swirler, and the first annular structure faces the combustion space.

11. The combustion chamber according to claim 10, characterized in that The connecting piece is welded to the pre-combustion stage swirler.

12. An aircraft engine, characterized in that: Comprising a combustion chamber as claimed in any one of claims 10-11.

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