A flame tube double-layer wall injection structure and aviation gas turbine engine

Abstract

The present invention belongs to the field of aircraft engines, and specifically relates to a double-walled flame tube injection structure and an aircraft gas turbine engine, comprising a flame tube, the flame tube comprising an air inlet end and an air outlet end, a fuel cavity being arranged around the tube wall of the flame tube, the fuel cavity being connected to a fuel inlet pipe; a plurality of premixing tubes are also arranged around the wall surface, the premixing tubes being located within the fuel cavity, the premixing tubes being provided with fuel nozzles, and the fuel in the fuel cavity entering the premixing tubes through the fuel nozzles; one end of the premixing tubes is an air inlet, and the other end is a micro-premixing outlet; the air inlet passes through the outer wall of the flame tube, and the micro-premixing outlet passes through the wall surface of the flame tube. The present invention reduces the volume and weight of the entire engine by arranging the premixing section on the side wall of the flame tube, making it more suitable for use in aircraft engines.

Description

Technical Field

[0001] The present invention belongs to the field of aviation engines, and in particular relates to a flame tube double-layer wall injection structure and an aviation gas turbine engine. Background Art

[0002] Hydrogen is a clean fuel, producing only water as a combustion product, without the emission of pollutants such as carbon dioxide, soot, and sulfides. However, hydrogen burns quickly, releases concentrated heat, and produces high flame temperatures, making it more susceptible to thermal nitrogen oxide (NOx) emissions. The currently widely adopted technology for reducing NOx emissions in hydrogen-fueled combustors is premixed combustion, where the fuel and air are premixed and then injected into the flame tube from the top of the tube for combustion.

[0003] Chinese patent: CN111765491B discloses a natural gas gas turbine micro-premixed combustion chamber applied to a wet air cycle, comprising a burner body, a flame tube and a combustion chamber casing, wherein the burner body is arranged at the head of the combustion chamber; the flame tube is arranged in the combustion chamber casing and is a cylindrical wall surface that wraps the combustion chamber, and the inner side of the wall surface is the combustion zone of the combustion chamber; a main fuel inlet and a service fuel inlet are provided at the front end of the burner body, the main fuel inlet is used to input fuel into the main nozzle of the burner; the service fuel inlet is used to input fuel into the service nozzle of the burner; an air chamber is provided at the bottom of the combustion chamber, the air chamber is wrapped by the gas turbine casing, and is connected to the gap formed by the combustion chamber liner and the flame tube, and the air from the upstream compressor outlet is sent into the burner air compartment through the gap.

[0004] However, this patent sets the premixing section at the head of the flame tube combustion chamber. The premixing section set in this way is thick and bulky, and is only suitable for use in ground combustion engines, but not for use in aircraft engines.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a double-wall injection structure of a flame tube and an aviation gas turbine engine. The present invention reduces the volume and weight of the entire engine by arranging the premixing section on the side wall of the flame tube, making it more suitable for use in aviation engines.

[0007] The present invention includes the following technical solutions:

[0008] The first aspect of the present invention provides a double-wall injection structure of a flame tube, including a flame tube, the flame tube including an air inlet end and an air outlet end, a fuel cavity is arranged around the tube wall of the flame tube, and the fuel cavity is connected to a fuel inlet pipe; a plurality of premixing tubes are also arranged around the wall, the premixing tubes are located in the fuel cavity, and a fuel nozzle is provided on the premixing tube, and the fuel in the fuel cavity enters the premixing tube through the fuel nozzle; one end of the premixing tube is an air inlet, and the other end is a micro-premixing outlet; the air inlet passes through the outer wall of the flame tube, and the micro-premixing outlet passes through the wall of the flame tube.

[0009] Furthermore, in some embodiments, the fuel chamber is formed by connecting the wall surface and the outer wall of the flame tube.

[0010] Furthermore, in some embodiments, the wall surface includes an outer wall and an inner wall, and both the outer wall and the inner wall are connected to the outer wall of the flame tube.

[0011] Furthermore, a plurality of fuel nozzles are provided.

[0012] Furthermore, a plurality of fuel nozzles are evenly arranged around the wall of the premixing tube.

[0013] Furthermore, a supporting structure is provided between the wall surface and the outer wall of the flame tube.

[0014] Furthermore, a plurality of premixing tubes are evenly arranged outside the flame tube.

[0015] Furthermore, the premixing tubes and the support structures are staggered.

[0016] Furthermore, the fuel inlet pipe is connected to both ends of the fuel cavity.

[0017] A second aspect of the present invention provides an aviation gas turbine engine, comprising a compressor, a combustion chamber, a turbine and the above-mentioned injection structure, wherein the compressor is connected to the combustion chamber, the combustion chamber is connected to the turbine, and the injection structure is arranged in the combustion chamber.

[0018] The technical solution of the present invention includes the following advantages:

[0019] 1. The present invention arranges the premixing section on the side wall of the flame tube, thereby reducing the volume and weight of the entire engine, making it more suitable for use in aircraft engines.

[0020] 2. The present invention provides a fuel cavity around the flame tube, which can better preheat the fuel and utilize the low temperature of the fuel to cool the flame tube wall to prevent wall erosion.

[0021] 3. The fuel chamber of the present invention is arranged outside the flame tube and welded to the flame tube as one body, which reduces the number of parts inside the combustion chamber and the assembly workload, and has higher reliability.

[0022] 4. The present invention utilizes the larger space on the outer surface of the inner ring of the flame tube to achieve multi-point injection, which can promote the mixed combustion of fuel inside the flame tube and facilitate ignition, flame connection and combustion.

[0023] 5. The multi-point injection of the present invention can achieve more uniform combustion, reduce the presence of high-temperature points in the flame tube, and reduce nitrogen oxide emissions.

[0024] 6. The flame tube and outer wall of the present invention are thin-walled sheet metal structures, which can be stamped and formed in one step, with simple structure, fast processing speed and low cost.

[0025] 7. The support structure of the present invention can prevent the outer wall of the flame tube from being deformed due to high temperature, welding, vibration, etc., squeezing the fuel cavity space, causing uneven cross-sectional area of ​​the hydrogen flow channel, and affecting the uniformity of hydrogen ejection.

[0026] 8. The staggered distribution of the premixing tubes and the supporting structure of the present invention can ensure the smooth flow of hydrogen from the interlayer space to the hydrogen nozzle, thereby improving the uniformity of hydrogen ejection.

[0027] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a schematic cross-sectional view of a double-wall injection structure of a flame tube according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1 Schematic diagram of the local structure;

[0031] Figure 3 This is a schematic diagram of a portion of the structure of the outer wall in an embodiment of the present invention;

[0032] Figure 4 for Figure 3 Schematic diagram of the local structure;

[0033] In the figure: 10-flame tube, 11-flame tube wall, 111-outer wall, 112-inner wall, 20-fuel chamber, 30-premixing tube, 31-fuel nozzle, 32-air inlet, 33-micro-premixing outlet, 40-flame tube outer wall, 50-support structure. DETAILED DESCRIPTION

[0034] The following description provides many different embodiments or examples for implementing different features of the present invention. The components and arrangements described in the following specific examples are only used to simplify the present invention and are only used as examples, not to limit the present invention.

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0036] This embodiment provides a double-layer wall spray structure of the flame tube 10, such as Figure 1 As shown, it includes a flame tube 10, which includes an air inlet end and an air outlet end. Figure 1In the figure, the left opening is the air outlet end of the flame tube 10, and the high-temperature combustion gas discharged from the air outlet end enters the turbine to do work. The right side is the air inlet end of the flame tube 10 (i.e., the air inlet end corresponding to the combustion chamber). Since the flame tube 10 is arranged in the combustion chamber, the air in the combustion chamber enters the flame tube 10 for combustion. In addition to the air entering the flame tube 10 through micro-premixing, an air inlet hole is provided on the flame tube wall 11 where the fuel cavity 20 is not provided. This method can promote combustion and cool the wall surface. At the same time, an air inlet hole can also be provided at the air inlet end of the flame tube 10 to let in air. A fuel cavity 20 is provided around the wall 11 of the flame tube 10, and the fuel cavity 20 is connected to a fuel inlet pipe. It should be noted that the fuel inlet pipe is not shown in the figure. The fuel inlet pipe The number of is not limited. Preferably, the fuel inlet pipes are uniformly distributed circumferentially, which has the advantage of improving the uniformity of hydrogen entering the premixing tube 30. It should be noted that although the fuel inlet pipes are uniformly distributed circumferentially, this structure only requires a few fuel inlet pipes uniformly distributed circumferentially, plus a main pipe to realize the gas supply function. The main pipe can be arranged outside the casing, and the economy, assembly and maintainability are all optimal. In this way, the fuel inlet pipes are directly connected to the premixing tube 30. The number of fuel inlet pipes must match the number of premixing tubes 30. The numerous fuel inlet pipes will occupy the space of the two channels, which not only increases the weight but also affects the flow field. A plurality of premixing tubes 30 are also arranged around the outside of the flame tube 10. The premixing tube 30 is located in the fuel cavity 20. Figure 2 As shown, the wall of the premixing tube 30 is provided with a fuel nozzle 31, and the fuel in the fuel cavity 20 enters the premixing tube 30 through the fuel nozzle 31; one end of the premixing tube 30 is an air inlet 32, and the other end is a micro-premixing outlet 33; the air inlet 32 ​​is used to communicate with the combustion chamber, and the micro-premixing outlet 33 is connected to the flame tube 10.

[0037] In the double-wall injection structure of the present invention, hydrogen enters the fuel chamber 20 through the fuel inlet pipe; air is sucked into the aircraft engine through the compressor, and under the action of the compressor, the compressed air enters the combustion chamber. The compressed air entering the combustion chamber enters the premixing tube 30, and is slightly premixed with the hydrogen entering the premixing tube 30 through the fuel nozzle before entering the flame tube 10.

[0038] The structural fuel chamber 20 of the present invention can only be used to introduce hydrogen, not air. If air is introduced into the fuel chamber 20, hydrogen must be introduced into the premixing tube 30. There are two ways to introduce hydrogen: (1) directly introducing hydrogen into the combustion chamber, that is, introducing hydrogen into the combustion chamber through the fuel inlet pipe. However, the hydrogen entering the combustion chamber will mix with the air (because the air must pass through the compressor to enter the combustion chamber), and will burn outside the flame tube 10, causing the engine to burn out and stop; (2) directly connecting the fuel inlet pipe to the premixing tube 30, and introducing hydrogen directly into the premixing tube 30. However, since there are too many premixing tubes 30 and they are arranged in a surrounding manner, this method requires the installation of a large number of fuel inlet pipes, which is not only difficult to implement structurally, but also increases costs.

[0039] It should be noted that Figure 1 The flame tube 10 is only a partial structural diagram. The existing flame tube 10 has an annular structure. The wall 11 of the flame tube 10 includes an inner wall 112 and an outer wall 111. The combustion chamber of the flame tube 10 is between the inner wall 112 and the outer wall 111.

[0040] Furthermore, in some embodiments, Figure 1 、 Figure 2 As shown, the fuel chamber 20 is formed by connecting the wall 11 with the outer wall 40 of the flame tube. The outer wall 40 and the flame tube wall 11 are formed by a single stamping process and are connected by welding. Preferably, the outer wall 40 of the flame tube is annular, which has the advantages of increasing the heat exchange area and facilitating the arrangement of injection points. This not only improves the wall cooling effect, but also helps to improve the uniformity of hydrogen in the flame tube, thereby improving combustion efficiency.

[0041] Furthermore, in some embodiments, Figure 1 As shown, the wall surface 11 includes an outer wall 111 and an inner wall 112, and the outer wall 111 and the inner wall 112 are both connected to the flame tube outer wall 40. An annular flame tube outer wall 40 is provided outside the outer wall 111, and a flame tube outer wall 40 is provided inside the inner wall 112; the axial ends of the annular flame tube outer wall 40 are connected to the wall surface 11 of the flame tube 10 by welding.

[0042] Furthermore, in some embodiments, Figure 2As shown, the premixing tube 30 has an air inlet 32 ​​at one end and a micro-premixing outlet 33 at the other end; the air inlet 32 ​​penetrates the outer wall 40 of the flame tube, and the micro-premixing outlet 33 penetrates the flame tube wall 11 (i.e., the micro-premixing outlet 33 disposed between the inner wall 112 and the outer wall 40 of the flame tube penetrates the inner wall 112 of the flame tube; the micro-premixing outlet 33 disposed between the outer wall 111 and the outer wall 40 of the flame tube penetrates the outer wall 111). By providing the fuel cavity 20 and the premixing tube 30 on both the inner wall 112 and the outer wall 111, the micro-premixed gas entering the flame tube 10 is more uniform, further improving combustion efficiency and temperature field uniformity.

[0043] Furthermore, in some embodiments, a plurality of fuel nozzles 31 are provided.

[0044] Furthermore, in some embodiments, a plurality of fuel nozzles 31 are evenly arranged around the wall of the premixing tube 30. This makes the hydrogen entering the premixing tube 30 more uniform, has a better micro-premixing effect, and is conducive to improving combustion efficiency.

[0045] Since the flame tube 10 and the flame tube outer wall 40 may be deformed due to the influence of high temperature, welding, vibration, etc., resulting in uneven cross-sectional area of ​​the hydrogen flow channel, in order to avoid deformation, further, in some embodiments, a support structure 50 is provided between the wall surface 11 and the flame tube outer wall 40. The support structure 50 is at least in contact with the wall surface 11 and the flame tube outer wall 40, so the support structure 50 provided between the wall surface 11 and the flame tube outer wall 40 can be fixedly connected to the wall surface 11 at one end and only in contact with the flame tube outer wall 40 at the other end, or fixedly connected to the flame tube outer wall 40 at one end and only in contact with the wall surface 11 at the other end, or fixedly connected to the wall surface 11 at one end and fixedly connected to the flame tube outer wall 40 at the other end.

[0046] Therefore, further, in some embodiments, the support structure 50 and the premixing tube 30 are staggered; specifically, as Figure 3 As shown, the staggered distribution should be understood as that the support structure 50 and the premixing tube 30 are alternately arranged, and the support structure 50 and the premixing tube 30 are arranged in the same manner, that is, both are arranged around the flame tube wall 11; if a regular arrangement is adopted, the support structure 50 is arranged around a circle evenly, and then the premixing tube 30 is arranged adjacent to it on both sides. Similarly, the support structures 50 are also arranged adjacent to each other on both sides of the premixing tube 30; however, it should be noted that the premixing tube 30 located at the end has only one side of the support structure 50, or the support structure 50 located at the end has only one side of the premixing tube 30.

[0047] Furthermore, in some embodiments, a plurality of premixing tubes 30 are evenly arranged outside the flame tube 10, so that the micro-premixed gas entering the flame tube 10 is more uniform, achieving a better continuous flame effect, making the combustion more complete, and the temperature field more uniform.

[0048] Furthermore, in some embodiments, the fuel cavity 20 is positioned corresponding to the primary combustion zone of the flame tube 10. Specifically, the hydrogen within the fuel cavity 20 primarily dissipates heat from the walls of the primary combustion zone of the flame tube 10. This not only allows the hydrogen to obtain more heat, resulting in better combustion, but also provides a better cooling effect on the flame tube 10. The fuel cavity 20 is positioned corresponding to the primary combustion zone, allowing the micro-premixed gas entering the flame tube 10 to directly enter the primary combustion zone for combustion, facilitating flame cross-coupling and improving temperature field stability.

[0049] Furthermore, the flame tube 10 and the flame tube outer wall 40 are both made of thin-walled sheet metal.

[0050] This embodiment also provides an aviation gas turbine engine, including a compressor, a combustion chamber, a turbine and the injection structure described above, wherein the compressor is connected to the combustion chamber, the combustion chamber is connected to the turbine, and the injection structure is arranged in the combustion chamber.

[0051] Working principle: Air enters the compressor to generate compressed air, which enters the combustion chamber. The compressed air in the combustion chamber enters the premixing tube 30 and the flame tube 10 respectively. The air entering the premixing tube 30 is premixed with the hydrogen entering the premixing tube 30 and then enters the flame tube 10 for combustion. The high-temperature combustion gas generated by the combustion enters the turbine to perform work.

[0052] The turbine engine of the present invention has the advantages of light weight and good performance.

[0053] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical, electrical, or intercommunication connections; direct or indirect connections through an intermediary; and may encompass internal connectivity between multiple components or interactions between multiple components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0054] In the description of the present invention, it should be understood that all terms used to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and cannot be understood as a limitation on the present invention.

[0055] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flame tube double-wall injection structure, comprising a flame tube (10), the flame tube (10) comprising an air inlet end and an air outlet end, characterized in that: A fuel cavity (20) is arranged around the wall surface (11) of the flame tube (10), and the fuel cavity (20) is connected to a fuel inlet pipe; a plurality of premixing tubes (30) are also arranged around the wall surface (11), and the premixing tubes (30) are located in the fuel cavity (20), and the tube walls of the premixing tubes (30) are provided with fuel nozzles (31); one end of the premixing tube (30) is an air inlet (32), and the other end is a micro-premixing outlet (33), and the fuel in the fuel cavity (20) enters the premixing tube (30) through the fuel nozzle (31); the air inlet (32) is communicated with the combustion chamber, and the micro-premixing outlet (33) is communicated with the flame tube (10); The fuel cavity (20) is formed by connecting a wall surface (11) and an outer wall (40) of the flame tube; The wall surface (11) includes an outer wall (111) and an inner wall (112), and both the outer wall (111) and the inner wall (112) are connected to the outer wall (40) of the flame tube; A support structure (50) is provided between the wall surface (11) and the outer wall (40) of the flame tube; A plurality of premixing tubes (30) are evenly arranged around the wall surface (11); The premixing tubes (30) and the support structures (50) are staggered; The fuel inlet pipes are connected to both ends of the fuel cavity (20); the fuel inlet pipes are evenly distributed in the circumferential direction.

2. The double-walled flame tube spray structure according to claim 1, characterized in that: A plurality of fuel nozzles (31) are provided.

3. The double-walled flame tube spray structure according to claim 2, characterized in that: A plurality of fuel nozzles (31) are evenly arranged around the wall of the premixing tube (30).

4. An aviation gas turbine engine, characterized in that: It comprises a compressor, a combustion chamber, a turbine and the injection structure according to claim 1, wherein the compressor is connected to the combustion chamber, the combustion chamber is connected to the turbine, and the injection structure is arranged in the combustion chamber.

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