Swirler and combustion chamber

Abstract

The swirler is fixed to an adapter section of the head of a combustion chamber through a connecting piece and comprises an annular main body, a first axial extension part, a second axial extension part, an abutting boss and a cooling hole, the annular main body comprises radial lugs and a pair of anti-rotation bosses arranged on the radial lugs, and the anti-rotation bosses and the radial lugs define a U-shaped space; the U-shaped space is used for accommodating the connecting piece; the second axial extension part and the first axial extension part are respectively arranged on two axial sides of the annular main body; the abutting boss is arranged on the peripheral side of the first axial extension part. The cooling holes penetrate through the annular body and are circumferentially arranged. The swirler has a good end face cooling effect. A combustion chamber is also provided.

Description

Technical Field

[0001] The invention relates to the field of aeroengines, and in particular to the field of swirlers in combustion chambers. Background Art

[0002] The swirl finder (Mixer) is an important component of the combustion chamber of an aircraft engine, which affects the overall performance of the combustion chamber. The swirl finder forms a swirl and forms a recirculation zone in the flame tube to stabilize the flame, improve fuel atomization and promote the formation of combustible mixture.

[0003] At present, with the development of high performance and high pressure ratio of advanced aircraft engine combustion chambers, the engine pressure ratio continues to increase, the cycle efficiency continues to improve, and the combustion chamber inlet temperature is further increased, and its temperature exceeds 1000K, so that the fuel nozzle is subjected to a large thermal load under high-temperature airflow. At the same time, during the operation of the fuel nozzle, in order to avoid the nozzle and the vortex finder being stuck due to the different expansion amounts of the nozzle, flame tube and casing under the thermal load, the vortex finder is designed as a free-floating structure in the combustion chamber of modern aircraft engines to adapt to the influence of different deformation amounts caused by different temperatures between different components. In addition, the working environment of the combustion chamber flame tube is becoming more and more harsh. Since the nozzle and the front end of the vortex finder are directly subjected to the high temperature and harsh environment, there is still a certain risk of ablation of the vortex finder. Summary of the invention

[0004] An object of the present invention is to provide a vortex finder which has a better end surface cooling effect.

[0005] To achieve the above-mentioned purpose, the vortex finder is fixed on the combustion chamber head transition section through a connecting piece, and includes an annular body, a first axial extension portion, a second axial extension portion, a top boss and a cooling hole. The annular body includes a radial lug and a pair of anti-rotation bosses arranged on each of the radial lugs, and the anti-rotation bosses and the radial lugs form a U-shaped space, and the U-shaped space is used to accommodate the connecting piece; the second axial extension portion and the first axial extension portion are respectively arranged on both axial sides of the annular body; the top boss is arranged on the outer peripheral side of the first axial extension portion; the cooling hole penetrates the annular body and is arranged circumferentially.

[0006] In one or more embodiments, a circumferential groove is provided between the second axial extension portion and the annular body, and one end of the cooling hole is connected to the circumferential groove.

[0007] In one or more embodiments, the vortex finder further comprises a plurality of swirl grooves circumferentially distributed on the second axial extension portion.

[0008] In one or more embodiments, the swirl groove is a rectangular groove.

[0009] In one or more embodiments, the height of the abutting boss is greater than the radial height of the cooling hole.

[0010] In one or more embodiments, a pair of radial lugs are distributed on the upper and lower sides of the annular body.

[0011] In one or more embodiments, an outer diameter of the first axially extending portion is configured to be smaller than an outer diameter of the second axially extending portion.

[0012] In one or more embodiments, the annular body comprises a groove located at the outlet of the cooling hole.

[0013] In one or more embodiments, the abutting boss is arranged on the upper and lower sides of the first axial extension portion.

[0014] Another object of the present invention is to provide a combustion chamber, which includes a head transition section, a fuel nozzle, a pressure plate and the above-mentioned vortex finder, wherein the U-shaped space of the vortex finder is connected to the head transition section through the pressure plate, and the fuel nozzle extends into the interior of the vortex finder and floats with the vortex finder.

[0015] The above-mentioned vortex finder is able to effectively prevent the circumferential rotation of the vortex finder by arranging a pair of anti-rotation bosses on the radial lugs. At the same time, by removing the ear structures on both sides, the influence of the ear structures on both sides on the intake volume is avoided, so that there is no obstruction between adjacent vortex finders, thereby providing an appropriate amount of uniform air for the head; the fixed abutment platform is located at the place where the vortex finder is in direct contact with the flame. After positioning, the cooling air can smoothly pass through the small holes to cool the end face of the vortex finder, thereby avoiding the influence of backfire or high temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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:

[0017] Figure 1 It is a structural cross-sectional view of the combustion chamber of an aircraft engine;

[0018] Figure 2 It is a schematic diagram of the connection structure between the vortexer and the combustion chamber head transition section;

[0019] Figure 3 is a schematic diagram of an embodiment of a vortex finder;

[0020] Figure 4 It is a schematic diagram of the connection relationship between the vortex finder and the connecting piece;

[0021] Figure 5 is a schematic diagram of cooling holes;

[0022] Figure 6 is a side view of the vortex finder;

[0023] Figure 7 yes Figure 6 Enlarged view of point N in the middle. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] Figure 1 The structure of an aircraft engine combustion chamber is shown in a cross-sectional view, including a flame tube outer ring 1, a fuel nozzle 2, a head transition section 3, inner and outer caps 4, a flame tube inner ring 5, a combustion chamber outer casing 6, a front diffuser 7, a vortex finder 8 and other components.

[0027] The vortex finder 8 is fixed to the head transition section 3 by two upper and lower pressure plates, and each pressure plate is fixed to the head transition section and the inner and outer rings of the flame tube by bolts. Figure 1 The upper pressure plate 9 shown is fixed to the head transition section 3 and the flame tube outer ring 1 by bolts. The swirler 8 is assembled by the axial gap between the pressure plate and the head transition section 3. The swirler 8 is arranged on the outer periphery of the tail of the fuel nozzle 2 to achieve free floating with the fuel nozzle 2.

[0028] like Figure 2 As shown, modern aircraft engines generally use annular combustion chambers. After the high-pressure gas is discharged from the compressor and enters the combustion chamber, it is mainly divided into three air flows. The first stream directly enters the outer annular cavity channel of the combustion chamber to cool the outer ring of the flame tube and the ignition nozzle device; the second stream directly enters the inner annular cavity channel of the combustion chamber to cool the inner ring of the flame tube; the third stream enters the combustion reaction chamber from the head of the combustion chamber to fully mix with the fuel. Under the action of the ignition nozzle, the mixed gas undergoes a violent chemical reaction and burns to produce high-temperature combustion gas. With the development of modern technology, the working environment of the flame tube of the aircraft engine combustion chamber is becoming more and more harsh. Since the front end of the fuel nozzle 2 and the vortexer 8 are directly subjected to the high temperature and harsh environment, there is a certain risk of ablation.

[0029] Therefore, the present application discloses a vortex finder that can move freely relative to a fuel nozzle without affecting the circumferential uniform air volume. The vortex finder can withstand high temperature environments through some cooling paths and has the advantages of easy processing and convenient assembly and disassembly.

[0030] The vortex finder 8 is fixed to the combustion chamber head transition section 3 through a connecting piece, and in some embodiments, the connecting piece is the above-mentioned pressure plate 9. The vortex finder 8 includes an annular body 810, a first axial extension portion 820, a second axial extension portion 830, an abutting boss 840 and a cooling hole 850.

[0031] like Figures 3 to 7 As shown, the annular body 810 includes a radial lug 811 and a pair of anti-rotation bosses 812 disposed on each radial lug 811. The anti-rotation bosses 812 and the radial lugs 811 form a U-shaped space 813. The U-shaped space 813 is used to accommodate connecting parts such as a pressure plate, such as Figure 4 shown.

[0032] In this way, the pressure plate 9 is in the U-shaped space 813 surrounded by the anti-rotation boss 812 and the radial lug 811, and the anti-rotation boss 812 plays a circumferential limiting role, cooperating with the pressure plate to directly achieve circumferential anti-rotation.

[0033] Preferably, the vortex finder 8 includes a pair of radial lugs 811, which are respectively distributed on the upper and lower sides of the annular body 810, rather than the left and right sides. By removing the lug structures on the left and right sides, the influence of the lug structures on the two sides on the intake volume is avoided, so that there is no obstruction between adjacent vortex finders, and an appropriate amount of uniform air is provided to the head to ensure that the main nozzle of the fuel nozzle is evenly mixed with the air, avoid disturbance, and reduce the risk of combustion oscillation. At the same time, by removing the lug structures on both sides of the circumference, it is possible to smoothly realize that the vortex finder groove and U-shaped groove structure can be processed by bar stock. Compared with the traditional casting method, it avoids the influence of the low yield rate of the early castings, and ensures that the mating part, that is, the boss structure, can be directly repaired by welding during the rework process, so that maintenance is convenient, time is shortened, and better economic performance is achieved.

[0034] The anti-rotation boss structure of this scheme only needs to design one configuration of vortex finder to realize the function, and does not require the use of multiple configurations of main vortices.

[0035] In order to prevent the vortex finder from being affected by the heat load caused by the backfire or the high temperature area being too close to the head, a cooling air is designed on the air inlet side of the vortex finder. The annular body 810 is also provided with cooling holes 850 distributed circumferentially, such as Figure 5 and Figure 7 As shown, the cooling air B flows to the end face of the vortex finder through the cooling holes 850 to cool the end face of the vortex finder. The cooling holes 850 evenly arranged circumferentially provide an appropriate amount of uniform air to the head to ensure that the main nozzle of the fuel nozzle is evenly mixed with the air, avoid disturbances, and reduce the risk of combustion oscillation.

[0036] like Figure 7 As shown, the annular body 810 further includes a groove 814 located at the outlet of the cooling hole 850 to guide the cooling gas B to flow out.

[0037] The cooling holes 850 may be Figure 7 The straight hole shown may also be an inclined hole. The aspect ratio of the groove 814 may also be adjusted according to actual cooling requirements.

[0038] The first axial extension portion 820 and the second axial extension portion 830 are respectively arranged on both axial sides of the annular body. Relatively speaking, the first axial extension portion 820 is close to the combustion chamber side, and the second axial extension portion 830 is far from the combustion chamber side.

[0039] The second axial extension 830 is provided with a plurality of swirl grooves 870 distributed circumferentially to provide head air intake C. The head air intake C cooperates with the nozzle fuel to generate a high-speed rotating jet at the head of the flame tube, forming a low-pressure area, thereby creating a reflow area to ensure flame stability; and the high-speed rotating jet increases the relative speed of the airflow and the oil droplets, improving the fuel atomization and the formation of mixed air.

[0040] The top boss 840 is arranged on the outer peripheral side of the first axial extension 820, and is located at the place where the vortex finder directly contacts the flame, that is, at the outlet of the fuel nozzle. Since the nozzle, flame tube, and casing are affected by thermal loads, the nozzle and the vortex finder are generally designed as a free-floating structure due to different expansion amounts. In order to prevent the vortex finder from being affected by the thermal load of flashback or the high-temperature area being too close to the head, cooling gas B is designed on the air inlet side of the vortex finder; at the same time, in order to avoid the influence of the nozzle in the working state, the vortex finder is free to float, resulting in the cooling hole 850 being covered, and the above-mentioned top boss 840 is designed.

[0041] In some embodiments, the abutting bosses 840 are disposed on upper and lower sides of the first axial extension portion 820 .

[0042] During the normal operation of the nozzle, the nozzle drives the vortex finder to move upward relative to the flame tube due to the thermal deformation of the nozzle and the flame tube. Figure 2 The floating clearance A shown. The floating clearance is the free floating amount, and the top boss 840 can abut against the head transition section 3 when the vortex finder moves overloaded, preventing the entire vortex finder 8 from being completely fitted with the head transition section 3 and blocking the cooling air from the cooling hole 850 from entering, thereby ensuring that the cooling air can smoothly pass through the small hole to cool the end face of the vortex finder after positioning, avoiding the influence of tempering or high temperature.

[0043] Therefore, in some embodiments, the height of the abutting boss 840 is greater than the radial height of the cooling hole 850, so that when the abutting boss 840 abuts the combustion chamber head transition section 3, sufficient cooling space can still be left for the cooling gas.

[0044] In addition, the outer diameter of the first axial extension portion 8220 is set to be smaller than the outer diameter of the second axial extension portion 830, and a circumferential groove 860 is provided between the second axial extension portion 830 and the annular body 810. One end of the cooling hole 850 is connected to the circumferential groove 860, and the cooling gas B flows from the circumferential groove 860 to the cooling hole 850, and then flows to the end face of the first axial extension portion 820.

[0045] The above-mentioned vortex finder is designed with two anti-rotation bosses on the radial lugs that fix the vortex finder on the pressure plate, thereby achieving circumferential clockwise and counterclockwise anti-rotation of the vortex finder; at the same time, the lugs on both sides are eliminated to ensure the air intake; a top boss is also provided at the place where the vortex finder is directly in contact with the flame, which cooperates with the cooling hole to ensure that the cooling gas can always smoothly cool the end face of the vortex finder to avoid the influence of backfire or high temperature.

[0046] Combined with the introduction of the above vortex finder, it can also be understood that a combustion chamber including the above vortex finder, the head adapter section 3 is matched with the U-shaped space on the annular body 810 of the vortex finder through the pressure plate 9, and the fuel nozzle 2 extends into the inner cavity 800 of the vortex finder 8 and floats with the vortex finder 8. Therefore, the vortex finder can move freely without affecting the circumferential uniform gas volume, and also has better cooling performance to withstand the high temperature environment of the combustion chamber.

[0047] 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.

[0048] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0049] 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.

[0050] 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. The vortex finder is fixed to the combustion chamber head transition section through a connecting piece, characterized in that: include: An annular body, comprising radial lugs and a pair of anti-rotation bosses arranged on each of the radial lugs, wherein the anti-rotation bosses and the radial lugs enclose a U-shaped space, and the U-shaped space is used to accommodate the connecting member; a first axial extension; A second axial extension portion, which is arranged on both axial sides of the annular body respectively with the first axial extension portion; an abutting boss, arranged on the outer peripheral side of the first axial extension portion; and The cooling holes penetrate the annular body and are circumferentially arranged.

2. The vortex finder according to claim 1, characterized in that: A circumferential groove is provided between the second axial extension portion and the annular body, and one end of the cooling hole is connected to the circumferential groove.

3. The vortex finder according to claim 1, characterized in that: The vortex finder also includes a plurality of swirl grooves circumferentially distributed on the second axial extension portion.

4. The vortex finder according to claim 3, characterized in that: The swirl groove is a rectangular groove.

5. The vortex finder according to claim 1, characterized in that: The height of the abutting boss is greater than the radial height of the cooling hole.

6. The vortex finder according to claim 1, characterized in that: A pair of radial lugs are distributed on the upper and lower sides of the annular body.

7. The vortex finder according to claim 1, characterized in that: An outer diameter of the first axially extending portion is configured to be smaller than an outer diameter of the second axially extending portion.

8. The vortex finder according to claim 1, characterized in that: The annular body includes a groove located at an exit of the cooling hole.

9. The vortex finder according to claim 1, characterized in that: The abutting bosses are arranged on upper and lower sides of the first axial extension portion.

10. A combustion chamber, characterized in that include: A head transition section, a fuel nozzle, a pressure plate and a vortex finder as described in any one of claims 1 to 9, wherein the U-shaped space of the vortex finder is connected to the head transition section through the pressure plate, and the fuel nozzle extends into the interior of the vortex finder and floats with the vortex finder.

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