Fuel injection device, combustion chamber and aeroengine

Abstract

The application provides a fuel injection device, a combustion chamber and an aero-engine, and belongs to the technical field of aero-engines.The fuel injection device is used in the combustion chamber of an aero-engine, and the fuel injection device comprises a jet end, the jet end is provided with a main combustion stage jet hole and a secondary combustion stage jet hole, the main combustion stage jet hole is located on the outer circumferential side of the secondary combustion stage jet hole, and the jet direction of the secondary combustion stage jet hole is inclined towards the outer circumferential side of the secondary combustion stage jet hole.The structure is arranged so that the secondary combustion stage fuel jetted by the secondary combustion stage jet hole is jetted towards the main combustion stage backflow gas, and moves to the vicinity of an ignition device together with the main combustion stage backflow gas, the success rate of ignition of the secondary combustion stage fuel is improved, meanwhile, the secondary combustion stage fuel is jetted in an inclined manner, the diffusion range of the secondary combustion stage fuel is expanded, the ignition boundary of the secondary combustion stage is widened, and the energy requirement of the ignition system is reduced.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to a fuel injection device, a combustion chamber, and an aero-engine. Background Technology

[0002] Currently, aircraft engines, especially aircraft turbine engines, primarily use aviation kerosene as fuel. Aviation kerosene is a typical high-carbon-to-hydrogen fossil fuel, and its exhaust gases are a major source of CO2 and various pollutants at high altitudes. To reduce CO2 emissions, aircraft engine fuels are transitioning from aviation kerosene to various clean energy sources. The most ideal clean energy source is hydrogen, which theoretically can achieve zero carbon emissions. Compared to other liquid or gaseous hydrocarbon fuels, hydrogen has advantages such as abundant sources, light weight, high energy density, environmental friendliness, and diverse storage and utilization methods. Its complete combustion product is water, which does not cause environmental pollution. However, hydrogen also has characteristics such as strong diffusion, flammability and explosiveness, and high storage requirements. These characteristics are conducive to the widespread use of hydrogen as fuel in aircraft engines.

[0003] Existing fuel injection systems for aero engines are not suitable for hydrogen injection, ignition, and flame stabilization. In existing technology, aero engines have fuel injection systems within their combustion chambers, typically employing a central staged injection system to separately inject primary and secondary combustion stage fuels. Inside the combustion chamber, the primary combustion stage airflow rotates to form a low-speed recirculation zone, used to stabilize the combustion flame. In traditional central staged combustion chambers, secondary combustion stage fuel is only injected at ignition and low operating conditions to create the initial high-temperature zone within the combustion chamber and ignite the primary combustion stage fuel injected after the operating conditions increase. The secondary combustion stage fuel injection orifice is generally located in the center of the injection system. Centrifugal nozzles generate high-speed tangential centrifugal force in the liquid fuel, forming a spray that propels it outwards from the injection system. This injection method requires the secondary combustion stage fuel to pass through the primary combustion stage airflow to reach the vicinity of the ignition device after injection. However, insufficient initial momentum of the secondary combustion stage fuel injection or excessively high primary combustion stage airflow velocity can result in insufficient fuel reaching the ignition device, leading to poor combustibility and reduced ignition success rate, necessitating repeated activation of the ignition system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to improve the ignition success rate of secondary fuel in the fuel injection device of the combustion chamber of an aero-engine in the prior art, and to provide a fuel injection device, a combustion chamber and an aero-engine.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A fuel injection device for use in the combustion chamber of an aircraft engine, the fuel injection device comprising:

[0007] The injection end is provided with a main combustion stage injection hole and a secondary combustion stage injection hole. The main combustion stage injection hole is located on the outer periphery of the secondary combustion stage injection hole, and the injection direction of the secondary combustion stage injection hole is inclined toward the outer periphery of the secondary combustion stage injection hole.

[0008] In this design, the main combustion stage injection orifice at the injection end of the fuel injection device is located on the outer periphery of the secondary combustion stage injection orifice. The injection direction of the secondary combustion stage injection orifice is inclined towards the outer periphery of the secondary combustion stage injection orifice, so that the secondary combustion stage fuel injected by the secondary combustion stage injection orifice is injected towards the main combustion stage fuel injected by the main combustion stage injection orifice, and moves with the main combustion stage return gas to the vicinity of the ignition device, which improves the success rate of secondary combustion stage fuel ignition. At the same time, because the secondary combustion stage fuel is injected at an angle, the diffusion range of the secondary combustion stage fuel is expanded, the secondary combustion stage ignition boundary is widened, and the energy demand of the ignition system is reduced.

[0009] Preferably, the injection end includes an injection panel, on which the secondary combustion stage injection hole is provided, the primary combustion stage injection hole is arranged around the outer periphery of the injection panel, and the injection direction of the secondary combustion stage injection hole is inclined relative to the axial direction of the injection panel and faces the outer periphery of the injection panel.

[0010] In this design, the injection panel has a simple structure, making it easy to process and install. Each secondary combustion stage injection hole is located on the injection panel, and the secondary combustion stage fuel is injected from the same plane, which is beneficial for the uniform injection of the secondary combustion stage fuel. The main combustion stage injection hole is located on the outer periphery of the injection panel, which facilitates the secondary combustion stage fuel to be carried by the main combustion stage return gas to the vicinity of the ignition device, thereby improving the success rate of the secondary combustion stage fuel being ignited.

[0011] Preferably, the injection panel is provided with a secondary combustion stage air hole, which is located on the inner peripheral side of the secondary combustion stage injection hole and / or on the outer peripheral side of the secondary combustion stage injection hole.

[0012] In this design, the secondary combustion air orifice is used to inject secondary combustion air. The secondary combustion air flowing through the secondary combustion air injection orifice can cool the injection panel, prevent high-temperature flames from damaging the injection panel, extend the service life of the injection panel, and improve the working safety performance of the fuel injection device.

[0013] Preferably, the fuel injection device further includes a cylindrical secondary combustion stage injector, one end of which is covered by the injection panel. The secondary combustion stage injector has a cylindrical secondary combustion stage fuel chamber inside, and the secondary combustion stage injection holes are connected to the secondary combustion stage fuel chamber. A plurality of the secondary combustion stage injection holes are distributed in a ring on the injection panel.

[0014] In this design, the secondary combustion stage fuel chamber is cylindrical, which facilitates the uniform distribution of the secondary combustion stage fuel within the chamber. The annularly distributed secondary combustion stage injection holes on the injection panel are connected to the cylindrical secondary combustion stage fuel chamber. The secondary combustion stage fuel is uniformly ejected through the injection holes, which is beneficial for the diffusion and ignition of the secondary combustion stage fuel, resulting in a secondary combustion stage flame with a relatively uniform temperature.

[0015] Preferably, the secondary combustion stage injector includes an inner ring wall and an outer ring wall of the secondary combustion stage, the outer ring wall of the secondary combustion stage is disposed on the outer peripheral side of the inner ring wall of the secondary combustion stage, and the secondary combustion stage fuel chamber is located between the outer ring wall and the inner ring wall of the secondary combustion stage.

[0016] In this scheme, a cylindrical secondary combustion stage fuel chamber is formed by the outer and inner annular walls of the secondary combustion stage. The cylindrical secondary combustion stage fuel chamber guides and disperses the secondary combustion stage fuel, which is then ejected through the secondary combustion stage injection holes.

[0017] Preferably, the injection panel is provided with a first-stage air hole and a second-stage air hole, and the fuel injection device is provided with a first-stage air chamber and a second-stage air chamber, the first-stage air chamber being connected to the first-stage air hole, and the second-stage air chamber being connected to the second-stage air hole;

[0018] In the radial direction of the fuel injection device, the first combustion stage air chamber, the second combustion stage fuel chamber, and the third combustion stage air chamber are arranged sequentially from the inside to the outside.

[0019] In this design, a first-stage air chamber and a second-stage air chamber are respectively provided on the inner and outer circumferences of the secondary combustion stage fuel chamber. The first-stage air in the first-stage air chamber and the second-stage air in the second-stage air chamber are ejected through the first-stage air hole and the second-stage air hole, respectively. During the ejection process, the first-stage air and the second-stage air can cool down the injection panel and prevent the high-temperature flame from damaging the injection panel.

[0020] Preferably, the fuel injection device further includes a cylindrical main combustion stage injector, which is sleeved on the outer periphery of the secondary combustion stage injector. The main combustion stage injector has a cylindrical main combustion stage fuel chamber inside, and the main combustion stage injector has a main combustion stage injection hole communicating with the main combustion stage fuel chamber.

[0021] In this scheme, the main combustion stage fuel in the main combustion stage fuel chamber is ejected through the main combustion stage injection hole. After the main combustion stage fuel is injected, it forms a main combustion stage oil mist, which moves downstream with the main combustion stage air, evaporates and mixes to form a main combustion stage mixed gas, which is distributed circumferentially on the outer periphery of the secondary combustion stage flame, thus surrounding the secondary combustion stage flame and facilitating the ignition of the main combustion stage fuel by the secondary combustion stage flame.

[0022] Preferably, one end of the main combustion stage injector is connected to the outer peripheral edge of the injection panel. The main combustion stage injector includes an inner ring wall of the main combustion stage and an outer ring wall of the main combustion stage disposed on the outer peripheral side of the inner ring wall of the main combustion stage. The main combustion stage fuel chamber is located between the outer ring wall of the main combustion stage and the inner ring wall of the main combustion stage. The secondary combustion stage air chamber is located between the inner ring wall of the main combustion stage and the outer ring wall of the secondary combustion stage.

[0023] In this design, the main combustion stage injector is circumferentially connected to the outer periphery of the injection panel, forming an enclosure around the secondary combustion stage injector. The secondary combustion stage air chamber separates the main combustion stage fuel chamber and the secondary combustion stage fuel chamber. At the same time, a cylindrical main combustion stage fuel chamber is formed by the outer and inner ring walls of the main combustion stage, which facilitates the guidance of the main combustion stage fuel and its ejection through the main combustion stage injection holes.

[0024] Preferably, the plurality of secondary combustion stage injection holes, and / or the plurality of primary combustion stage air holes, and / or the plurality of secondary combustion stage air holes are arranged in several rings on the injection panel and are evenly distributed along the rings.

[0025] In this design, the secondary combustion stage injection holes, primary combustion stage air holes, and secondary combustion stage air holes are arranged in a ring on the injection panel, enabling the secondary combustion stage fuel and air to be injected in a diffuse manner. That is, the selection and arrangement of the injection points themselves have a certain diffusion effect, and they are evenly distributed on each ring, which facilitates the uniform injection of secondary combustion stage fuel and air. When set as a multi-ring configuration, the rings are nested and spaced apart, further increasing the uniformity of secondary combustion stage fuel injection and expanding the injection range of secondary combustion stage fuel, improving the ignition success rate of secondary combustion stage fuel, reducing the secondary combustion stage flame temperature, and reducing the emission of other pollutants caused by high temperature.

[0026] Preferably, the acute angle formed between the axis of the secondary combustion stage injection hole and the axis of the injection panel is 20°-60°.

[0027] In this design, the acute angle formed between the axis of the secondary combustion stage injection hole and the axis of the injection panel is 20°-60°, which allows the injected secondary combustion stage fuel to have a large diffusion range, making it easier for it to enter the main combustion stage return gas and move with the main combustion stage return gas to the vicinity of the ignition device, where it will be ignited.

[0028] Preferably, the fuel injection device further includes a cylindrical outer cover, which is fitted around the outer periphery of the main combustion stage injector. A main combustion stage air chamber is formed between the outer cover and the main combustion stage injector. The main combustion stage injection holes are arranged along the outer periphery of the main combustion stage injector, and the openings of the main combustion stage injection holes face and communicate with the main combustion stage air chamber.

[0029] In this design, the outer casing is fitted around the outer periphery of the main combustion stage injector, enclosing both the main and secondary combustion stage injectors and providing support for their internal structure. A main combustion stage air chamber exists between the outer casing and the main combustion stage injector. The main combustion stage injection holes are connected to this air chamber, with their openings facing it. This allows the main combustion stage fuel to be injected into the air chamber, facilitating its evaporation and mixing with the main combustion stage air to form a more uniform fuel-air mixture, i.e., the main combustion stage mixed gas. This promotes the combustion of the main combustion stage fuel, reduces flame temperature, and decreases emissions of pollutants generated at high temperatures.

[0030] Preferably, the fuel injection device further includes a plurality of swirl vanes, which are inclinedly disposed within the main combustion stage air chamber.

[0031] In this design, the inclined swirl vanes within the main combustion stage air chamber create a swirling flow of air within the chamber. This swirling air ejected from the main combustion stage air chamber has low-speed and high-speed zones. The region near the axis of the injection panel is the low-speed zone, while the region away from the axis is the high-speed zone. The low-speed air helps stabilize the high-temperature flame downstream of the fuel injection device.

[0032] Preferably, the fuel injection device further includes a distribution pipe, which has a secondary combustion stage channel and a primary combustion stage channel, the secondary combustion stage channel being connected to the secondary combustion stage fuel chamber, and the primary combustion stage channel being connected to the primary combustion stage fuel chamber;

[0033] The secondary combustion stage injector is provided with a clearance groove on the side near the main combustion stage channel, and the distribution pipe is located in the clearance groove.

[0034] In this design, the feeds to the secondary combustion stage fuel chamber and the primary combustion stage fuel chamber are integrated into the distribution pipe, saving space occupied at the feed end. Furthermore, part of the distribution pipe is located within the clearance groove of the secondary combustion stage injector, meaning that the distribution pipe extends into the interior of the fuel injection device, providing a certain degree of support for the connection end of the distribution pipe.

[0035] A combustion chamber comprising the fuel injection device described above.

[0036] In this scheme, the combustion chamber is equipped with the aforementioned fuel injection device, which allows the secondary combustion stage fuel to easily diffuse into the main combustion stage return gas and be carried by the main combustion stage return gas to the vicinity of the ignition device, thereby improving the success rate of ignition of the secondary combustion stage fuel. At the same time, since the secondary combustion stage fuel is injected at an angle, the diffusion range of the secondary combustion stage fuel is expanded, the ignition boundary of the secondary combustion stage is widened, the energy demand of the ignition system is reduced, and the combustion temperature of the secondary combustion stage fuel is reduced, thereby reducing the generation of high-temperature pollutants.

[0037] An aircraft engine comprising the combustion chamber described above.

[0038] In this design, the aero-engine, by setting up the aforementioned combustion chamber, allows for a wider and faster dispersion of the secondary combustion stage fuel injection, increasing the success rate of secondary combustion stage fuel ignition. At the same time, because the secondary combustion stage fuel is injected at an angle, its diffusion range is greater, which can reduce the temperature of the secondary combustion stage flame formed after the secondary combustion stage fuel is ignited, improve the working performance of the aero-engine, and reduce the generation of high-temperature pollutants.

[0039] The positive and progressive effects of this invention are as follows:

[0040] In this invention, the main combustion stage injection hole at the injection end of the fuel injection device is located on the outer periphery of the secondary combustion stage injection hole. The injection direction of the secondary combustion stage injection hole is inclined towards the outer periphery of the secondary combustion stage injection hole, so that the secondary combustion stage fuel injected by the secondary combustion stage injection hole is injected towards the main combustion stage return gas and moves with the main combustion stage return gas to the vicinity of the ignition device, which improves the success rate of secondary combustion stage fuel ignition. At the same time, since the secondary combustion stage fuel is injected at an angle, the diffusion range of the secondary combustion stage fuel is expanded, the secondary combustion stage ignition boundary is widened, and the energy demand of the ignition system is reduced. Moreover, this fuel injection device is compatible with most existing combustion chamber configurations and ignition methods that use aviation kerosene combustion, without having to redesign the combustion chamber structure. Attached Figure Description

[0041] Figure 1 This is a three-dimensional structural diagram of a fuel injection device according to an embodiment of the present invention.

[0042] Figure 2 This is a three-dimensional structural schematic diagram of a fuel injection device according to an embodiment of the present invention from another perspective.

[0043] Figure 3 This is a front view of a fuel injection device according to an embodiment of the present invention.

[0044] Figure 4 for Figure 3 A schematic diagram of the AA cross-sectional structure.

[0045] Figure 5 for Figure 4 A schematic diagram of the BB cross-sectional structure.

[0046] Figure 6 for Figure 4 A schematic diagram of the CC cross-sectional structure.

[0047] Figure 7 This is a three-dimensional structural diagram of the injection panel of a fuel injection device according to an embodiment of the present invention.

[0048] Figure 8 This is a front view of the injection panel of a fuel injection device according to an embodiment of the present invention.

[0049] Figure 9 for Figure 8 A schematic diagram of the DD cross-sectional structure.

[0050] Figure 10 This is a schematic diagram of the ignition and flame combustion under low operating conditions of a fuel injection device according to an embodiment of the present invention.

[0051] Figure 11 This is a schematic diagram of flame combustion under medium-high operating conditions of a fuel injection device according to an embodiment of the present invention.

[0052] Figure 12 This is a cross-sectional structural diagram of a combustion chamber according to an embodiment of the present invention.

[0053] Figure 13 This is a cross-sectional structural diagram of an aero-engine according to an embodiment of the present invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] Injection end 1

[0056] Spray Panel 11

[0057] Main combustion stage injection port 111

[0058] Secondary combustion stage injection hole 112

[0059] First combustion stage air port 113

[0060] Secondary combustion stage air port 114

[0061] Secondary combustion stage injector 2

[0062] Secondary combustion stage fuel chamber 21

[0063] Secondary combustion stage inner ring wall 22

[0064] Secondary combustion stage outer ring wall 23

[0065] Secondary combustion stage end cap 24

[0066] 25 clearance slots

[0067] First combustion stage air chamber 3

[0068] Second combustion stage air chamber 4

[0069] Main combustion stage injection component 5

[0070] Main combustion stage fuel chamber 51

[0071] 52mm inner ring wall of main combustion stage

[0072] Main combustion stage outer ring wall 53

[0073] Main combustion stage end cap 54

[0074] Outer cover 6

[0075] Main combustion stage air chamber 7

[0076] 8 swirl blades

[0077] Distribution pipe 9

[0078] Secondary combustion stage passage 91

[0079] Main combustion stage channel 92

[0080] Combustion chamber 100

[0081] Fuel injection device 101

[0082] Flame tube 102

[0083] Ignition device 103

[0084] Aircraft Engine 200

[0085] Main combustion grade fuel 301

[0086] Main combustion grade oil mist 3011

[0087] Secondary combustion fuel 302

[0088] Main combustion grade air 303

[0089] Secondary combustion air 304

[0090] First-stage combustion air 3041

[0091] Secondary combustion stage air 3042

[0092] Electrical Discharge Machining 305

[0093] 306 main combustion stage reflux gas

[0094] Secondary combustion stage flame 307

[0095] First high temperature zone 308

[0096] 309 main combustion stage gas mixture

[0097] Second high temperature zone 310

[0098] 311 Main combustion stage feed pipe

[0099] Secondary combustion stage feed pipe 312 Detailed Implementation

[0100] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments described herein.

[0101] like Figures 1 to 11 As shown, this embodiment provides a fuel injection device 101 for the combustion chamber 100 of an aero-engine 200. The fuel injection device 101 includes an injection end 1, which is provided with a main combustion stage injection hole 111 and a secondary combustion stage injection hole 112. The main combustion stage injection hole 111 is located on the outer periphery of the secondary combustion stage injection hole 112, and the injection direction of the secondary combustion stage injection hole 112 is inclined toward the outer periphery of the fuel injection device 101. The above-mentioned structural configuration causes the secondary combustion stage fuel 302 injected from the secondary combustion stage injection hole 112 to be injected toward the main combustion stage return gas 306 and move with the main combustion stage return gas 306 to the vicinity of the ignition device 103, thereby improving the success rate of the secondary combustion stage fuel 302 being ignited. At the same time, since the secondary combustion stage fuel 302 is injected at an angle, the diffusion range of the secondary combustion stage fuel 302 is expanded, the secondary combustion stage ignition boundary is widened, and the energy demand of the ignition system is reduced. Moreover, the fuel injection device 101 is compatible with most configurations and ignition methods of existing combustion chambers 100 that use aviation kerosene combustion, without the need to redesign the structure of the combustion chamber 100.

[0102] In this embodiment, the injection end 1 includes an injection panel 11, on which secondary combustion stage injection holes 112 are provided, and primary combustion stage injection holes 111 are arranged around the outer periphery of the injection panel 11. The injection direction of the secondary combustion stage injection holes 112 is inclined relative to the axial direction of the injection panel 11 and faces the outer periphery of the injection panel 11. The injection panel 11 has a simple structure, which is convenient for processing and installation. Each secondary combustion stage injection hole 112 is located on the injection panel 11, and the secondary combustion stage fuel 302 is injected from the same plane, which is beneficial to the uniform injection of the secondary combustion stage fuel 302. The primary combustion stage injection holes 111 are located on the outer periphery of the injection panel 11, which facilitates the secondary combustion stage fuel 302 to be carried by the primary combustion stage return gas 306 to the vicinity of the ignition device 103, thereby improving the success rate of ignition of the secondary combustion stage fuel 302.

[0103] In this embodiment, the injection panel 11 is provided with secondary combustion stage air holes, which are located on the inner and outer periphery sides of the secondary combustion stage injection hole 112. The secondary combustion stage air holes are used to inject secondary combustion stage air 304. The secondary combustion stage air 304 flowing through the secondary combustion stage injection hole 112 can cool the injection panel 11, preventing damage to the injection panel 11 from the high-temperature flame, extending the service life of the injection panel 11, and improving the operational safety performance of the fuel injection device 101. Specifically, in this embodiment, the secondary combustion stage air holes include a primary combustion stage air hole 113 located on the inner periphery side of the secondary combustion stage injection hole 112 and a secondary combustion stage air hole 114 located on the outer periphery side of the secondary combustion stage injection hole 112. In other optional embodiments, the injection panel 11 may only have a primary combustion stage air hole 113 or only have a secondary combustion stage air hole 114.

[0104] In this embodiment, the fuel injection device 101 further includes a cylindrical secondary combustion stage injector 2. One end of the secondary combustion stage injector 2 is covered with an injection panel 11. The secondary combustion stage injector 2 has a cylindrical secondary combustion stage fuel chamber 21 inside. Secondary combustion stage injection holes 112 are connected to the secondary combustion stage fuel chamber 21. Multiple secondary combustion stage injection holes 112 are distributed in a ring on the injection panel 11. The cylindrical shape of the secondary combustion stage fuel chamber 21 is beneficial for the uniform distribution of the secondary combustion stage fuel 302 in the secondary combustion stage fuel chamber 21. The ring-shaped secondary combustion stage injection holes 112 on the injection panel 11 are correspondingly connected to the cylindrical secondary combustion stage fuel chamber 21. The secondary combustion stage fuel 302 is uniformly sprayed out through the secondary combustion stage injection holes 112, which is beneficial for the diffusion and ignition of the secondary combustion stage fuel 302, forming a secondary combustion stage flame 307 with a relatively uniform temperature.

[0105] In this embodiment, the secondary combustion stage injector 2 includes an inner ring wall 22 and an outer ring wall 23. The outer ring wall 23 is located on the outer periphery of the inner ring wall, and the secondary combustion stage fuel chamber 21 is located between the outer ring wall 23 and the inner ring wall 22. The cylindrical secondary combustion stage fuel chamber 21 is formed by the outer ring wall 23 and the inner ring wall 22. The cylindrical secondary combustion stage fuel chamber 21 guides and disperses the secondary combustion stage fuel 302 and ejects it through the secondary combustion stage injection hole 112. Specifically, in this embodiment, the secondary combustion stage injector 2 further includes a secondary combustion stage end cap 24, which covers one end of the inner annular wall 22 and the outer annular wall 23 of the secondary combustion stage. The injection panel 11 covers the other end of the inner annular wall 22 and the outer annular wall 23 of the secondary combustion stage. The secondary combustion stage end cap 24, the inner annular wall 22, the outer annular wall 23, and the injection panel 11 together enclose the secondary combustion stage fuel chamber 21. Further, as... Figure 7 and Figure 9As shown, in this embodiment, the injection panel 11 is integrally formed with the inner ring wall 22 of the secondary combustion stage and part of the outer ring wall 23 of the secondary combustion stage. In other alternative embodiments, the injection panel 11 can also be manufactured separately and then connected to the secondary combustion stage injection component 2.

[0106] In this embodiment, the injection panel 11 is provided with a first-stage air hole 113 and a second-stage air hole 114. The fuel injection device 101 is provided with a first-stage air chamber 3 and a second-stage air chamber 4. The first-stage air chamber 3 is connected to the first-stage air hole 113, and the second-stage air chamber 4 is connected to the second-stage air hole 114. In the radial direction of the fuel injection device 101, the first-stage air chamber 3, the second-stage fuel chamber 21, and the second-stage air chamber 4 are arranged sequentially from the inside to the outside. The inner and outer circumferences of the secondary combustion stage fuel chamber 21 are respectively provided with a primary combustion stage air chamber 3 and a secondary combustion stage air chamber 4. The primary combustion stage air 3041 in the primary combustion stage air chamber 3 and the secondary combustion stage air 3042 in the secondary combustion stage air chamber 4 are ejected through the primary combustion stage air hole 113 and the secondary combustion stage air hole 114, respectively. The primary combustion stage air 3041 and the secondary combustion stage air 3042 can cool down the injection panel 11 during the ejection process, so as to avoid damage to the injection panel 11 by the high temperature flame.

[0107] In this embodiment, the fuel injection device 101 further includes a cylindrical main combustion stage injector 5, which is sleeved on the outer periphery of the secondary combustion stage injector 2. The main combustion stage injector 5 has a cylindrical main combustion stage fuel chamber 51 inside, and a main combustion stage injection hole 111 communicating with the main combustion stage fuel chamber 51. The main combustion stage fuel 301 in the main combustion stage fuel chamber 51 is ejected through the main combustion stage injection hole 111. After the main combustion stage fuel 301 is ejected, it forms a main combustion stage oil mist 3011, which moves downstream with the main combustion stage air 303, evaporates and mixes to form a main combustion stage mixed gas 309, which is circumferentially distributed on the outer periphery of the secondary combustion stage flame 307, surrounding the secondary combustion stage flame and facilitating the ignition of the main combustion stage fuel 301 by the secondary combustion stage flame. Specifically, in this embodiment, the main combustion stage injection hole 111 is located axially upstream of the injection panel 11 and radially outward of the injection panel 11, so as to allow a certain space and time for the evaporation and mixing of the main combustion stage fuel 301 after injection to form the main combustion stage mixed gas 309.

[0108] In this embodiment, one end of the main combustion stage injector 5 is connected to the outer peripheral edge of the injection panel 11. The main combustion stage injector 5 includes an inner ring wall 52 of the main combustion stage and an outer ring wall 53 of the main combustion stage located on the outer peripheral side of the inner ring wall 52. The main combustion stage fuel chamber 51 is located between the outer ring wall 53 and the inner ring wall 52 of the main combustion stage, and the secondary combustion stage air chamber 4 is located between the inner ring wall 52 and the outer ring wall 23 of the secondary combustion stage. The main combustion stage injector 5 is circumferentially connected to the outer peripheral side of the injection panel 11, forming an enclosure around the secondary combustion stage injector 2. The secondary combustion stage air chamber 4 separates the main combustion stage fuel chamber 51 and the secondary combustion stage fuel chamber 21. At the same time, the cylindrical main combustion stage fuel chamber 51 is formed by the outer ring wall 53 and the inner ring wall 52 of the main combustion stage, which can facilitate the guidance of the main combustion stage fuel 301 and its ejection through the main combustion stage injection hole 111. Specifically, in this embodiment, the main combustion stage injector 5 also includes a main combustion stage end cap 54, which covers one end of the main combustion stage inner ring wall 52 and the main combustion stage outer ring wall 53. The main combustion stage end cap 54, the main combustion stage inner ring wall 52 and the main combustion stage outer ring wall 53 together enclose the main combustion stage fuel chamber 51.

[0109] In this embodiment, multiple secondary combustion stage injection holes 112, multiple primary combustion stage air holes 113, and multiple secondary combustion stage air holes 114 are arranged in several rings on the injection panel 11 and are evenly distributed along their respective rings. Specifically, as shown... Figure 8 As shown, in this embodiment, the multiple secondary combustion stage injection holes 112 are arranged in a ring, and the multiple primary combustion stage air holes 113 and multiple secondary combustion stage air holes 114 are each arranged in three rings. The secondary combustion stage injection holes 112, primary combustion stage air holes 113 and secondary combustion stage air holes 114 are arranged in a ring on the injection panel 11, so that the secondary combustion stage fuel 302 and secondary combustion stage air 304 can be diffusedly injected. That is, the selection and arrangement of the injection points themselves have a certain diffusion effect, and they are evenly distributed on each ring, which facilitates the uniform injection of secondary combustion stage fuel 302 and secondary combustion stage air 304. When it is set as a multi-ring, the rings are nested and spaced apart, which further increases the uniformity of the injection of secondary combustion stage fuel 302 and expands the injection range of secondary combustion stage fuel 302, improves the ignition success rate of secondary combustion stage fuel 302, reduces the secondary combustion stage flame temperature, and reduces the generation of high-temperature pollutants. In other alternative embodiments, the number and specific arrangement of the plurality of secondary combustion stage injection holes 112, the plurality of primary combustion stage air holes 113, and the plurality of secondary combustion stage air holes 114 are not limited to this embodiment.

[0110] In this embodiment, the second-stage air orifice 114 is inclined toward the outer periphery of the injection panel 11, and the angle of inclination of the second-stage air orifice 114 toward the outer periphery of the injection panel 11 is smaller than the angle of inclination of the second-stage injection orifice 112 toward the outer periphery of the injection panel 11. Specifically, as shown... Figure 9As shown in the figure, θ is the angle at which the secondary combustion stage injection hole 112 is tilted toward the outer periphery of the injection panel 11. The value of θ can be selected based on factors such as the intensity of the main combustion stage return gas 306, the height of the flame tube 102 in the combustion chamber 100, and the position of the ignition device 103. The secondary combustion stage air hole 114 is arranged around the outer periphery of the secondary combustion stage injection hole 112, and the tilt angle of the secondary combustion stage air hole 114 is smaller than the tilt angle of the secondary combustion stage injection hole 112. This allows the secondary combustion stage fuel 302 ejected from the secondary combustion stage injection hole 112 to be sprayed toward the secondary combustion stage air 3042 ejected from the secondary combustion stage air hole 114, facilitating the mixing of the secondary combustion stage fuel 302 and the secondary combustion stage air 3042.

[0111] In this embodiment, the acute angle formed between the axis of the secondary combustion stage injection hole 112 and the axis of the injection panel 11 is 20°-60°. This allows the injected secondary combustion stage fuel 302 to have a large diffusion range, facilitating its entry into the main combustion stage return gas 306 and its movement with the main combustion stage return gas 306 to the vicinity of the ignition device 103, where it is then ignited by the ignition device 103.

[0112] In this embodiment, the fuel injection device 101 further includes a cylindrical outer cover 6, which is sleeved on the outer periphery of the main combustion stage injector 5. The outer cover 6 and the main combustion stage injector 5 enclose a main combustion stage air chamber 7. The main combustion stage injection hole 111 is arranged along the outer periphery of the main combustion stage injector 5, and the opening of the main combustion stage injection hole 111 faces and communicates with the main combustion stage air chamber 7. The outer casing 6 is fitted around the outer periphery of the main combustion stage injector 5, enclosing the main combustion stage injector 5 and the secondary combustion stage injector 2, and supporting their internal structure. There is a main combustion stage air chamber 7 between the outer casing 6 and the main combustion stage injector 5. The main combustion stage injection hole 111 is connected to the main combustion stage air chamber 7 and its opening faces the main combustion stage air chamber 7, so that the main combustion stage fuel 301 is injected towards the main combustion stage air chamber 7. This is beneficial for the evaporation of the main combustion stage fuel 301 and its mixing with the main combustion stage air 303 to form a relatively uniform fuel-air mixture, namely the main combustion stage mixed gas 309. This is beneficial for the combustion of the main combustion stage fuel 301, reduces the flame temperature, and reduces the generation and emission of high-temperature pollutants.

[0113] In this embodiment, the fuel injection device 101 further includes a plurality of swirl vanes 8, which are obliquely disposed within the main combustion stage air chamber 7. The obliquely disposed swirl vanes 8 within the main combustion stage air chamber 7 cause the main combustion stage air 303 within the main combustion stage air chamber 7 to form a swirling flow. The swirling air ejected from the main combustion stage air chamber 7 has a low-speed zone and a high-speed zone. The region near the axis of the injection panel 11 is the low-speed zone, and the region away from the axis of the injection panel 11 is the high-speed zone. The air in the low-speed zone is beneficial for stabilizing the high-temperature flame downstream of the fuel injection device 101.

[0114] In this embodiment, the fuel injection device 101 further includes a distribution pipe 9, which has a secondary combustion stage channel 91 and a primary combustion stage channel 92. The secondary combustion stage channel 91 is connected to the secondary combustion stage fuel chamber 21, and the primary combustion stage channel 92 is connected to the primary combustion stage fuel chamber 51. A clearance groove 25 is provided on the side of the secondary combustion stage injector 2 near the primary combustion stage channel 92, and part of the distribution pipe 9 is located in the clearance groove 25. The feeds to the secondary combustion stage fuel chamber 21 and the primary combustion stage fuel chamber 51 are integrated into the distribution pipe 9, saving the space occupied at the feed end. Moreover, part of the distribution pipe 9 is located in the clearance groove 25 of the secondary combustion stage injector 2, that is, the distribution pipe 9 extends into the interior of the fuel injection device 101, and provides a certain support for the connection end between the distribution pipe 9 and the primary combustion stage injector 5, as well as the connection end between the distribution pipe 9 and the secondary combustion stage injector 2.

[0115] In this embodiment, the fuel injection device 101 further includes a main combustion stage feed pipe 311 and a secondary combustion stage feed pipe 312. The main combustion stage feed pipe 311 is connected to the main combustion stage channel 92 of the distribution pipe 9, and the secondary combustion stage feed pipe 312 is connected to the secondary combustion stage channel 91 of the distribution pipe 9. Both the main combustion stage feed pipe 311 and the secondary combustion stage feed pipe 312 are partially surrounded by the main combustion stage injector 5 and the secondary combustion stage injector 2, and provide certain support for the connection end of the main combustion stage feed pipe 311 and the distribution pipe 9, as well as the connection end of the secondary combustion stage feed pipe 312 and the distribution pipe 9.

[0116] like Figure 12 As shown, this embodiment also provides a combustion chamber 100, which includes the aforementioned fuel injection device 101. By providing the aforementioned fuel injection device 101, the combustion chamber 100 facilitates the diffusion of the secondary combustion stage fuel 302 into the main combustion stage return gas 306 and its movement to the vicinity of the ignition device 103, thereby increasing the success rate of ignition of the secondary combustion stage fuel 302. Simultaneously, because the secondary combustion stage fuel 302 is injected at an angle, the diffusion range of the secondary combustion stage fuel 302 is expanded, widening the secondary combustion stage ignition boundary, reducing the energy demand of the ignition system, and lowering the temperature of the secondary combustion stage flame 307 formed after the secondary combustion stage fuel 302 is ignited, thus reducing the generation of high-temperature pollutants.

[0117] In this embodiment, the combustion chamber 100 further includes a flame tube 102 and an ignition device 103. The fuel injection device 101 is disposed at one end of the flame tube 102, and the ignition device 103 is disposed downstream of the fuel injection device 101 and on the side wall of the flame tube 102. The cross-sectional area of ​​the flame tube 102 gradually decreases along the injection direction of the fuel injection device 101. The cross-sectional area of ​​the flame tube 102 gradually decreases along the downstream direction of the fuel injection device 101. When the operating conditions of the aero-engine increase, the main combustion stage fuel 301 begins to be injected (at this time, the secondary combustion stage fuel 302 has been ignited). The main combustion stage mixed gas 309 injected by the fuel injection device 101 (i.e., the mixed gas formed after the main combustion stage fuel 301 evaporates and mixes in the main combustion stage air 303) moves downstream, igniting the secondary combustion stage flame it encloses, forming a larger stable main combustion stage flame, which also encloses the secondary combustion stage flame 307.

[0118] In this embodiment, the secondary combustion stage fuel 302 is hydrogen, and the primary combustion stage fuel 301 is aviation kerosene. The working principle of the fuel injection device 101 is as follows:

[0119] Please see Figure 10 and combined Figure 12 When the combustion chamber 100 is in ignition mode or a lower mode, only secondary combustion stage fuel 302 is used for combustion. Specifically, when the aero-engine 200 is in ignition mode, only the secondary combustion stage injection port 112 injects secondary combustion stage fuel 302, i.e., hydrogen fuel, towards its outer periphery in the combustion chamber 100. After injection, the secondary combustion stage fuel 302 diffuses into the main combustion stage return gas 306 and is carried to the vicinity of the ignition device 103, where it is ignited by the electric spark 305 of the ignition device 103 to form high-temperature gas (the ignition device 103 stops working after the secondary combustion stage is successfully ignited). Some of the high-temperature gas flows back to the vicinity of the secondary combustion stage injection port 112 along with the main combustion stage return gas 306 (at this time, the main combustion stage return gas 306 mainly includes the main combustion stage air 303 and the secondary combustion stage fuel 302), igniting the newly injected secondary combustion stage fuel 302, so that the secondary combustion stage fuel 302 forms a stable secondary combustion stage flame 307 and a first high-temperature zone 308 after injection. When the operating condition of the aero-engine 200 increases but is still in a low operating condition, only the secondary combustion stage injection port 112 injects secondary combustion stage fuel 302, i.e. hydrogen fuel. However, the flow rate of secondary combustion stage hydrogen fuel 302 continues to increase. The newly entering secondary combustion stage hydrogen fuel 302 is ignited by the secondary combustion stage flame 307 or the secondary combustion stage high temperature zone 308 downstream of the fuel injection device 101, continuously expanding the area of ​​the secondary combustion stage flame 307 or the secondary combustion stage high temperature zone 308.

[0120] Please see Figure 11 and combined Figure 12When the combustion chamber 100 is under high operating conditions, the injection of primary combustion stage fuel 301 is increased simultaneously with the injection of secondary combustion stage fuel 302 (at this time, ignition has already occurred, the secondary combustion stage fuel 302 is in a combustion state, and a secondary combustion stage flame 307 has been generated). After the primary combustion stage fuel 301 is ejected through the primary combustion stage injection hole 111, it forms primary combustion stage oil mist 3011. The primary combustion stage oil mist 3011 evaporates in the primary combustion stage air chamber 7 and mixes with the primary combustion stage air 303 to form a primary combustion stage mixed gas 309. The primary combustion stage mixed gas 309 surrounds the outer periphery of the secondary combustion stage flame and is ignited by the secondary combustion stage flame 307, forming a second high-temperature zone 310, which continuously ignites newly entering primary combustion stage mixed gas 309, achieving stable combustion of the primary combustion stage fuel 301. Because the primary combustion stage fuel 301 adopts a premixed and pre-evaporated combustion method, the temperature of the primary combustion stage fuel 301 during combustion can be reduced, thereby reducing the generation of high-temperature pollutants.

[0121] In this embodiment, the hydrogen injection direction is inclined towards the outer periphery of the secondary combustion stage injection hole 112, and the hydrogen itself has strong diffusivity, making it easier for the hydrogen to reach the vicinity of the ignition device 103 with the main combustion stage return gas 306 to be ignited. This can be adapted to the configuration and ignition method of most existing combustion chambers 100 that use aviation kerosene combustion, without having to redesign the structure of the combustion chamber 100.

[0122] Furthermore, using hydrogen in the secondary combustion stage fuel 302 has the following beneficial effects: hydrogen is mainly used for ignition and combustion under low operating conditions; the amount of hydrogen fuel used is relatively small, and no complex pipeline support is required (if the amount of hydrogen used is large, additional pipeline design is required due to the significant difference in performance between hydrogen and aviation kerosene), making it suitable for improving the fuel injection device 101 of the combustion chamber 100 of the existing aero-engine 200; hydrogen is easily ignited, requiring low ignition energy, which can reduce the load on the ignition device 103; the low ignition energy and high flame propagation speed of hydrogen can significantly improve the ignition performance of the combustion chamber 100, thereby widening the ignition boundary, especially the ignition performance at high altitudes and plateaus; the combustion products of hydrogen are mainly water, which can reduce carbon emissions and save energy and protect the environment.

[0123] like Figure 13 As shown, this embodiment also provides an aircraft engine 200, which includes the aforementioned combustion chamber 100. By configuring the combustion chamber 100, the aircraft engine 200 allows for a wider and faster dispersion of the secondary combustion stage fuel 302, increasing the success rate of ignition. Furthermore, because the secondary combustion stage fuel 302 is injected at an angle, its diffusion range is further expanded, reducing its combustion temperature, improving the operating performance of the aircraft engine 200, and reducing the generation of high-temperature pollutants.

[0124] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A fuel injection device, characterized in that, The fuel injection device is used in the combustion chamber of an aircraft engine, and the fuel injection device includes: The injection end is provided with a main combustion stage injection hole and a secondary combustion stage injection hole. The main combustion stage injection hole is located on the outer periphery of the secondary combustion stage injection hole, and the injection direction of the secondary combustion stage injection hole is inclined toward the outer periphery of the secondary combustion stage injection hole. When the combustion chamber is in ignition condition or a lower condition, only secondary combustion stage fuel is used for combustion. The secondary combustion stage fuel is hydrogen fuel. Only the secondary combustion stage injection holes in the combustion chamber inject secondary combustion stage fuel towards their outer periphery. In ignition condition, after the secondary combustion stage fuel is injected, it diffuses into the main combustion stage return gas and is carried to the vicinity of the ignition device. It is ignited by the electric spark of the ignition device to form high-temperature gas, which continues to ignite the subsequently injected secondary combustion stage fuel. The injection end includes an injection panel, on which the secondary combustion stage injection hole is provided. The primary combustion stage injection hole is arranged around the outer periphery of the injection panel. The injection direction of the secondary combustion stage injection hole is inclined relative to the axial direction of the injection panel and faces the outer periphery of the injection panel. The injection panel is provided with a secondary combustion stage air hole, which includes a primary combustion stage air hole and a secondary combustion stage air hole. The secondary combustion stage air hole is located on the inner peripheral side and the outer peripheral side of the secondary combustion stage injection hole. The fuel injection device further includes a cylindrical secondary combustion stage injector, one end of which is covered by the injection panel. The secondary combustion stage injector has a cylindrical secondary combustion stage fuel chamber inside, and the secondary combustion stage injection holes are connected to the secondary combustion stage fuel chamber. A plurality of the secondary combustion stage injection holes are distributed in a ring on the injection panel. The fuel injection device includes a first-stage air chamber and a second-stage air chamber. The first-stage air chamber is connected to the first-stage air orifice, and the second-stage air chamber is connected to the second-stage air orifice. In the radial direction of the fuel injection device, the first-stage air chamber, the second-stage fuel chamber, and the second-stage air chamber are arranged sequentially from the inside to the outside. The fuel injection device further includes an outer cover and a main combustion stage injector. The outer cover is fitted around the outer periphery of the main combustion stage injector. A main combustion stage air chamber is formed between the outer cover and the main combustion stage injector. The main combustion stage injection hole is arranged along the outer periphery of the main combustion stage injector. The opening of the main combustion stage injection hole faces and communicates with the main combustion stage air chamber. The fuel injection device also includes multiple swirl vanes, which are inclinedly arranged in the main combustion stage air chamber; the first combustion stage air chamber and the second combustion stage air chamber have no swirl vanes.

2. The fuel injection device as claimed in claim 1, characterized in that, The secondary combustion stage injector includes an inner ring wall and an outer ring wall of the secondary combustion stage. The outer ring wall of the secondary combustion stage is located on the outer periphery of the inner ring wall of the secondary combustion stage, and the secondary combustion stage fuel chamber is located between the outer ring wall and the inner ring wall of the secondary combustion stage.

3. The fuel injection device as described in claim 2, characterized in that, The main combustion stage injector is cylindrical and is sleeved on the outer periphery of the secondary combustion stage injector. The main combustion stage injector has a cylindrical main combustion stage fuel chamber inside and a main combustion stage injection hole communicating with the main combustion stage fuel chamber.

4. The fuel injection device as described in claim 3, characterized in that, One end of the main combustion stage injector is connected to the outer peripheral edge of the injection panel. The main combustion stage injector includes an inner ring wall of the main combustion stage and an outer ring wall of the main combustion stage located on the outer peripheral side of the inner ring wall of the main combustion stage. The main combustion stage fuel chamber is located between the outer ring wall of the main combustion stage and the inner ring wall of the main combustion stage. The secondary combustion stage air chamber is located between the inner ring wall of the main combustion stage and the outer ring wall of the secondary combustion stage.

5. The fuel injection device as claimed in claim 4, characterized in that, The plurality of secondary combustion stage injection holes, and / or the plurality of primary combustion stage air holes, and / or the plurality of secondary combustion stage air holes are arranged in several rings on the injection panel and are evenly distributed along the rings.

6. The fuel injection device as claimed in claim 1, characterized in that, The acute angle formed between the axis of the secondary combustion stage injection hole and the axis of the injection panel is 20°-60°.

7. The fuel injection device as claimed in claim 3, characterized in that, The outer cover is cylindrical.

8. The fuel injection device as claimed in claim 3, characterized in that, The fuel injection device further includes a distribution pipe, which has a secondary combustion stage channel and a primary combustion stage channel. The secondary combustion stage channel is connected to the secondary combustion stage fuel chamber, and the primary combustion stage channel is connected to the primary combustion stage fuel chamber. The secondary combustion stage injector is provided with a clearance groove on the side near the main combustion stage channel, and the distribution pipe is located in the clearance groove.

9. A combustion chamber, characterized in that, The combustion chamber includes the fuel injection device as described in any one of claims 1-8.

10. An aircraft engine, characterized in that, The aircraft engine includes the combustion chamber as described in claim 9.

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