Swirler capable of improving ignition and flameout performance
By designing a stable bowl structure at the outlet position of the inner ring of the vortex, a stable axial return zone is formed, the problem of fuel atomization and combustion instability in the vortex is solved, and the engine's point-off performance and safety are improved.
Patent Information
- Application Number
- CN202510501263.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-08-01
AI Technical Summary
The existing vortex currents have weak tangential return zones in the small engine state, resulting in unstable fuel atomization and combustion, affecting ignition performance and engine safety.
Design a stable bowl structure at the outlet position of the inner ring of the vortex to form a stable axial return zone with a controllable dimension. By forming an axial return zone independent of the tangential speed behind the stable bowl, the fuel atomization and combustion speed are ensured.
It improves the engine's point-off performance in small states, ensures full atomization and stable combustion of fuel, and improves the overall performance and safety of the engine.
Smart Images
Figure CN120402929A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of aeroengines, and particularly to a swirler for improving ignition and extinction performance. Background Art
[0002] In the design of aeroengines, the high-altitude ignition performance and lean blowout performance are important indicators for evaluating the design quality of the main combustion chamber. These two performances are directly related to the safety and stability of the engine. Especially under extreme environmental conditions, such as high altitude with low temperature and low pressure or in a lean fuel state, ensuring reliable ignition and continuous and stable combustion is particularly important. To improve these key performances, various improvement measures have been proposed in the prior art, including improving the ignition system, adjusting the fuel supply law, and optimizing the design of the head of the flame tube, etc.
[0003] As the core area of the combustion process, the design of the head of the flame tube has a direct impact on fuel atomization, evaporation, and combustion speed. Although the traditional swirler design can promote the mixing of fuel and air to a certain extent, at low engine operating conditions, due to the weak tangential recirculation zone generated by the conventional swirler, it is difficult to provide sufficient turbulence intensity to ensure effective atomization and complete combustion of fuel, resulting in an increase in the ignition failure rate or unstable combustion, thereby affecting the overall performance and safety of the engine. Summary of the Invention
[0004] In view of this, the embodiments of this application provide a swirler for improving ignition and extinction performance, which at least partially solves the problem of poor ignition and extinction performance at low engine operating conditions in the prior art.
[0005] The embodiments of this application provide a swirler for improving ignition and extinction performance, including an outer ring, outer ring vanes, an intermediate ring, intermediate vanes, an inner ring, and a stabilizing bowl. The outer ring, intermediate ring, and inner ring are arranged from outside to inside in sequence. The outer ring vanes are arranged between the outer ring and the intermediate ring, and the intermediate vanes are arranged between the intermediate ring and the inner ring. An installation edge is installed on the outside of the outer ring. The stabilizing bowl is arranged at the outlet position of the intermediate ring. The stabilizing bowl is supported and connected to the outlet position of the intermediate ring through the inner ring. The stabilizing bowl is closed on the side close to the inlet of the swirler to form a bowl bottom, and is open on the side close to the outlet of the swirler to form a bowl mouth. The bowl mouth is set as an expanding structure.
[0006] According to a specific implementation manner of the embodiments of this application, cooling holes are arranged on the stabilizing bowl.
[0007] According to a specific implementation manner of the embodiments of this application, multiple circles of cooling holes are arranged on the stabilizing bowl. The cooling holes in the same circle are located on the same circumferential radius. There is an included angle between the center line of the cooling hole and the expanding generatrix of the stabilizing bowl. The distance from the air inlet end of the cooling hole to the center line is less than the distance from the air outlet end to the center line.
[0008] According to a specific implementation manner of the embodiment of the present application, the aperture diameter of the cooling hole meets the following requirements:
[0009] D < T * cosγ,
[0010] where D is the aperture diameter of the cooling hole, T is the wall thickness of the stable bowl, and γ is the angle between the center line of the cooling hole and the expansion generatrix of the stable bowl.
[0011] According to a specific implementation manner of the embodiment of the present application, the aperture diameter of the cooling hole is set to 0.5 mm to 1.5 mm.
[0012] According to a specific implementation manner of the embodiment of the present application, the bottom of the stable bowl is set to be arc-shaped.
[0013] According to a specific implementation manner of the embodiment of the present application, the inner ring support is set to be cylindrical, the diameter dimension of the inner ring support is set to 1 mm to 3 mm, and the number of circumferential distributions of the inner ring support is 3 to 8.
[0014] According to a specific implementation manner of the embodiment of the present application, the diameter of the open end of the stable bowl is equal to the diameter of the outlet end of the middle ring.
[0015] According to a specific implementation manner of the embodiment of the present application, the opening angle of the open end of the stable bowl is equal to the expansion angle of the outlet end of the middle ring.
[0016] According to a specific implementation manner of the embodiment of the present application, the wall thickness of the stable bowl is set to 0.5 mm to 3 mm.
[0017] Beneficial effects:
[0018] The swirl generator for improving the ignition and extinction performance in the embodiment of the present application, based on the swirl generator of the conventional engine main combustion chamber, by designing a stable bowl structure at the outlet position of the inner ring of the swirl generator, when the tangential recirculation zone generated by the conventional swirl generator is weak in the small state of the engine, an axial recirculation zone with a stable shape, controllable size, and independent of the tangential velocity can be formed behind the stable bowl, ensuring sufficient fuel atomization, evaporation, combustion speed, and flame connection ability, thereby improving the ignition and extinction performance of the engine. Description of the Drawings
[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0020] Figure 1 It is a schematic structural diagram of a swirl generator for improving the ignition and extinction performance according to an embodiment of the present invention;
[0021] Figure 2 1 is a comparison diagram of the large-scale recirculation area according to an embodiment of the present invention, (a) is the recirculation area of the vortex finder of the prior art, and (b) is the recirculation area of the vortex finder of the present invention;
[0022] Figure 3 1 is a comparison diagram of the small-state recirculation zone according to an embodiment of the present invention, (a) is the vortex finder recirculation zone of the prior art, and (b) is the vortex finder recirculation zone of the present invention.
[0023] In the figure: 1. Mounting edge; 2. Outer ring; 3. Outer ring blades; 4. Intermediate ring; 5. Intermediate blades; 6. Inner ring; 7. Inner ring support; 8. Stabilizing bowl; 81. Cooling hole; 9. First tangential recirculation zone; 10. Axial recirculation zone; 11. Second tangential recirculation zone; 12. Third tangential recirculation zone. DETAILED DESCRIPTION
[0024] The embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0025] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.
[0026] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.
[0027] It should also be noted that the illustrations provided in the following embodiments only schematically illustrate the basic concept of the present application. The illustrations only show the components related to the present application, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.
[0028] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.
[0029] An embodiment of the present application provides a swirler for improving the ignition and extinction performance. The following will refer to Figures 1 to 3 for a detailed description.
[0030] In one embodiment, the swirler for improving the ignition and extinction performance includes an outer ring vane 3, outer ring vane blades 3, an intermediate ring 4, intermediate vanes 5, an inner ring 6, and a stabilizing bowl 8. The outer ring vane 3, intermediate ring 4, and inner ring 6 are arranged in sequence from outside to inside. The outer ring vane blades 3 are arranged between the outer ring vane 3 and the intermediate ring 4. The intermediate vanes 5 are arranged between the intermediate ring 4 and the inner ring 6. An installation edge 1 is installed on the outside of the outer ring vane 3. The stabilizing bowl 8 is arranged at the outlet position of the intermediate ring 4. The stabilizing bowl 8 is connected to the outlet position of the intermediate ring 4 through an inner ring support 7. The stabilizing bowl 8 is closed on the side close to the inlet of the swirler to form a bowl bottom, and is open on the side close to the outlet of the swirler to form a bowl mouth. The bowl mouth is set as a divergent structure.
[0031] During specific implementation, the air flow passes through the channels formed between the intermediate vanes 5 and between the intermediate ring 4 and the stabilizing bowl 8 and flows from the inlet to the outlet. The air flow bypasses the stabilizing bowl 8 and flows from the high-pressure area with more gas to the low-pressure area with less gas (in the concave cavity of the stabilizing bowl 8), that is, a stable axial recirculation zone 10 is formed behind the stabilizing bowl 8. For the air flow principle of the swirler in this embodiment, refer to Figure 2 and Figure 3 , which details the comparison diagrams of the first tangential recirculation zone 9 formed by the swirler of the prior art in the large state of the engine and the axial recirculation zone 10 additionally generated inside the conventional second tangential recirculation zone 11 of the swirler of the present application, and also shows the comparison diagrams of the weaker third tangential recirculation zone 12 formed by the swirler of the prior art in the small state of the engine and the axially stable, size-controllable, and tangential velocity-independent axial recirculation zone 10 formed by this patent.
[0032] When the engine is in a low-power state, although the inlet pressure is relatively low, the air flow entering from the middle blades 5 of the swirler generates a radial flow away from the center due to the physical diversion of the stabilizing bowl 8. After passing over the open end of the stabilizing bowl 8, it flows towards the low-pressure area behind the stabilizing bowl 8 under the action of pressure and then flows axially counter-currently along the inner wall surface of the stabilizing bowl 8, forming an axially recirculating zone 10 with a stable shape, controllable size, and independent of the tangential velocity. The air flow entering from the outer ring blades 3 wraps around the above-mentioned axially recirculating zone 10 and flows backward, further stabilizing the recirculating zone and forming a recirculating zone with a larger size and stronger flame linking ability.
[0033] When the engine is in a high-power state, the above-mentioned axially recirculating zone 10 generated by the air flow entering from the middle blades 5 of the swirler still exists. The difference is that the air flow entering from the outer ring blades 3 has a relatively high inlet pressure, resulting in relatively high tangential and axial velocities. After passing over the axially recirculating zone 10, the air flow has enough ability to rush to a more downstream position, thus forming a low-pressure area behind the axially recirculating zone 10. The air flow that rushes to the more downstream position turns back and flows counter-currently forward. After encountering the air flow behind the axially recirculating zone 10, it flows radially away from the center, thus forming a larger second tangential recirculating zone 11.
[0034] Therefore, based on the conventional engine main combustion chamber swirler, by designing the stabilizing bowl 8 structure at the outlet position of the inner ring 6 of the swirler, when the tangential recirculating zone generated by the conventional swirler is relatively weak in the low-power state of the engine, an axially recirculating zone 10 with a stable shape, controllable size, and independent of the tangential velocity can be formed behind the stabilizing bowl 8, ensuring sufficient fuel atomization, evaporation, combustion speed, and flame linking ability, thereby improving the ignition and extinguishing performance of the engine.
[0035] Furthermore, cooling holes 81 are provided on the stabilizing bowl 8.
[0036] Furthermore, multiple circles of cooling holes 81 are provided on the stabilizing bowl 8. The cooling holes 81 in the same circle are located on the same circumferential radius. There is an included angle between the center line of the cooling holes 81 and the expansion generatrix of the stabilizing bowl 8. The distance from the intake end of the cooling holes 81 to the center line is less than the distance from the outlet end to the center line.
[0037] Furthermore, the aperture of the cooling holes 81 meets the following requirements:
[0038] D < T * cosγ,
[0039] where D is the aperture of the cooling holes 81, T is the wall thickness of the stabilizing bowl 8, and γ is the included angle between the center line of the cooling holes 81 and the expansion generatrix of the stabilizing bowl 8.
[0040] Furthermore, the aperture of the cooling holes 81 is set to be 0.5 mm to 1.5 mm.
[0041] During specific implementation, N circles of cooling holes 81 are arranged along the stable bowl 8. The distance between the distribution circles of each circle of cooling holes 81 along the expansion generatrix direction of the stable bowl 8 is Hx, the center distance of a circle of cooling holes 81 along the circumferential direction is Hz, the aperture D of the cooling holes 81 is between 0.5 mm and 1.5 mm. The central cooling hole 81 is a straight hole perpendicular to the wall surface. The included angle between the central lines of the remaining circles of cooling holes 81 and the expansion generatrix is γ, and the distance from the intake end of the cooling hole 81 to the center line is less than the distance from the outlet end to the center line.
[0042] The settings of the parameters of the cooling holes 81 need to meet the requirement that the cooling gas can flow from the intake end through the cooling holes 81 to the outlet end, and can reduce the wall temperature of the stable bowl 8 to the temperature that the selected material can withstand. At the same time, there is a certain remaining kinetic energy at the outlet of the cooling holes 81 to blow off the carbon deposit behind the stable bowl 8. Specifically, the matching design of the distance Hx between the distribution circles of each circle of cooling holes 81 along the expansion generatrix direction of the stable bowl 8, the center distance Hz of a circle of cooling holes 81 along the circumferential direction, the included angle γ between the central lines of the remaining circles of cooling holes 81 and the expansion generatrix, and the aperture D of the cooling holes 81 needs to ensure that the minimum wall thickness Tmin between the cooling holes 81 and between the cooling holes 81 and the outlet end face is greater than the wall thickness T of the stable bowl 8 to meet the strength requirements. The aperture D of the cooling holes 81 is less than the wall thickness T * cosγ of the stable bowl 8 to meet the requirement that the air flow at the inlet and outlet of the cooling holes 81 does not penetrate. The number of circles N of the cooling holes 81 arranged along the way needs to ensure that the inner wall surface of the stable bowl 8 is evenly covered with the cooling gas.
[0043] In one embodiment, the bottom of the stable bowl 8 is set to be circular arc-shaped. The radius of the circular arc line is R. The minimum value of the radius R should be such that the circular arc outer profile surface of the stable bowl 8 at the intake end is axially behind the throat of the middle ring 4, so as not to reduce the intake area of the throat of the middle ring 4; the maximum value of the radius R should be such that the vertical projection point of the outlet of the middle ring 4 on the expansion wall surface of the stable bowl 8 is behind the tangent point of the expansion wall surface straight line and the circular arc R in the air flow direction, so as to form an effective air flow guiding effect and reduce the pressure loss. At the same time, the setting of the inner circular arc surface can ensure that there will be no permanent pneumatic blind cavity inside the stable bowl 8, thus avoiding problems such as carbon deposit and ablation.
[0044] In one embodiment, the inner ring support 7 is set to be cylindrical. The diameter size of the inner ring support 7 is set to be 1 mm to 3 mm, and the number of the inner ring supports 7 distributed in the circumferential direction is 3 to 8.
[0045] During specific implementation, the stable bowl 8 arranged at the outlet position of the inner ring of the swirler 6 is connected and fixed to the middle ring 4 of the swirler through the inner ring supports 7 distributed in multiple circumferential positions, ensuring that the stable bowl 8 located at the center of the rotating air flow can be reliably fixed and does not affect the gas flow.
[0046] During specific implementation, there is an annular conical channel with a gap H between the stable bowl 8 and the middle ring 4. The design of the gap H should ensure that the minimum area Bmin of the formed annular conical channel is equal to the minimum value Amin of the channel area A1 between the middle vanes 5 and the throat area A2 of the middle ring 4. This gap can ensure that the minimum flow capacity of the air flow entering from the channel of the middle vanes 5 meets the design requirements when passing through this gap, and an axial recirculation zone 10 for forming a stable flame is formed at a position where the oil-gas concentration is appropriate closest to the head of the fuel nozzle.
[0047] In one embodiment, the diameter of the open end of the stable bowl 8 is equal to the diameter of the outlet end of the middle ring 4. This diameter size will not block the air flow entering from the vane channels of the outer ring vanes 3, and can ensure the maximization of the size of the axial recirculation zone 10 behind the stable bowl 8.
[0048] In one embodiment, the opening angle of the open end of the stable bowl 8 is equal to the expansion angle of the outlet end of the middle ring 4. The setting of the opening angle of the open end of the stable bowl 8 in this embodiment can ensure the theoretical maximum expansion angle of the air flow entering from the channel of the middle vanes 5 in a large state, thereby ensuring the size of the recirculation zone in a large state.
[0049] In one embodiment, the wall thickness of the stable bowl 8 is set to be 0.5 mm to 3 mm. The setting of this wall thickness can ensure sufficient strength while providing sufficient cooling length for the inclined air film holes.
[0050] The following is a specific structural setting of a swirler for improving the ignition performance, which is composed of a mounting edge 1, outer ring vanes 3, outer ring vane blades, middle ring 4, middle vanes 5, inner ring 6, inner ring support 7, and stable bowl 8, etc. Among them, the mounting edge 1, outer ring vanes 3, outer ring vane blades, middle ring 4, middle vanes 5, and inner ring 6 are of a conventional swirler structure. At the outlet position of the inner ring 6, the stable bowl 8 and the inner ring 6 are fixedly connected through inner ring supports 7 distributed at multiple circumferential positions. Among them, the cylindrical inner ring support 7 has a diameter of 1 mm and is evenly distributed circumferentially at 6 positions. The arc radius at the left end inlet of the stable bowl 8 is 5 mm, the expansion angle is 100°, the wall thickness of the stable bowl 8 is 1 mm, the gap between the stable bowl 8 and the inner ring 6 is 4 mm, the diameter of the open end of the stable bowl 8 is equal to the diameter at the outlet of the inner ring 6. A cooling hole 81 perpendicular to the wall surface is opened at the center of the stable bowl 8, and a total of 2 rows of cooling holes 81 with an included angle of 45° with the wall surface are arranged along the stable bowl 8 and evenly distributed circumferentially. There are 3 cooling holes 81 in the first row circumferentially and 6 cooling holes 81 in the second row circumferentially. The aperture of all cooling holes 81 is 0.8 mm.
[0051] In the embodiments provided by the present invention, on the basis of the conventional engine main combustion chamber swirler, by designing a stable bowl 8 structure at the outlet position of the inner ring 6 of the swirler, when the tangential recirculation zone generated by the conventional swirler is weak in the small state of the engine, an axially stable, controllable in size and tangential velocity-independent axially recirculation zone can be formed behind the stable bowl 8, ensuring sufficient fuel atomization, evaporation and combustion rates and flame linking ability, thereby improving the ignition and extinction performance of the engine.
[0052] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A swirler for improving the ignition and extinction performance, characterized in that It includes an outer ring (2), outer ring vanes (3), an intermediate ring (4), intermediate vanes (5), an inner ring (6), and a stabilizing bowl (8). The outer ring (2), intermediate ring (4), and inner ring (6) are arranged in sequence from outside to inside. The outer ring vanes (3) are arranged between the outer ring (2) and the intermediate ring (4), and the intermediate vanes (5) are arranged between the intermediate ring (4) and the inner ring (6). An installation edge (1) is installed on the outer side of the outer ring (2). The stabilizing bowl (8) is arranged at the outlet position of the intermediate ring (4). The stabilizing bowl (8) is connected to the outlet position of the intermediate ring (4) through an inner ring support (7). The stabilizing bowl (8) is closed on the side close to the inlet of the swirler to form a bowl bottom, and is open on the side close to the outlet of the swirler to form a bowl mouth. The bowl mouth is set as a divergent structure.
2. The vortex finder for improving the flameout performance according to claim 1, characterized in that: Cooling holes (81) are provided on the stabilizing bowl (8).
3. The swirler for improving the ignition and extinction performance according to claim 2, wherein, There are multiple circles of cooling holes (81) on the stabilizing bowl (8). The cooling holes (81) in the same circle are located on the same circumferential radius. There is an angle between the center line of the cooling holes (81) and the divergent generatrix of the stabilizing bowl (8). The distance from the air inlet end of the cooling holes (81) to the center line is less than the distance from the air outlet end to the center line.
4. The swirler for improving the ignition and extinguishing performance according to claim 3, characterized in that, The aperture of the cooling holes (81) meets the following requirements: D < T * cosγ, where D is the aperture of the cooling holes (81), T is the wall thickness of the stabilizing bowl (8), and γ is the angle between the center line of the cooling holes (81) and the divergent generatrix of the stabilizing bowl (8).
5. The swirl vane for improving ignition and extinguishing performance according to any one of claims 2-4, characterized in that, The aperture of the cooling holes (81) is set to be 0.5 mm to 1.5 mm.
6. The vortex finder for improving the flameout performance according to claim 1, characterized in that: The bowl bottom of the stabilizing bowl (8) is set to be arc-shaped.
7. The swirler for improving the ignition and extinction performance according to claim 1, wherein The inner ring support (7) is set to be cylindrical. The diameter size of the inner ring support (7) is set to be 1 mm to 3 mm, and the number of circumferential distributions of the inner ring support (7) is 3 to 8.
8. The swirler for improving the ignition and extinction performance according to claim 1, characterized in that, The diameter of the open end of the stabilizing bowl (8) is equal to the diameter of the outlet end of the intermediate ring (4).
9. The swirl generator for improving ignition and extinction performance according to claim 1, wherein The opening angle of the open end of the stabilizing bowl (8) is equal to the divergence angle of the outlet end of the intermediate ring (4).
10. The swirler for improving the ignition and extinction performance according to claim 1, characterized in that, The wall thickness of the stabilizing bowl (8) is set to be 0.5 mm to 3 mm.