Premixing and pre-evaporation type flame stabilizer with evaporation pipe

Abstract

According to the premixing and pre-evaporating type flame stabilizer with the evaporating pipe, the evaporating pipe and the gas guiding pipe are additionally arranged on the stabilizer, and a gas inlet channel is formed by the gas inlet ring and the flow dividing ring to introduce high-temperature fuel gas; an outlet channel is formed between the inner stabilizer and the outer stabilizer, high-temperature fuel gas is introduced into the outer culvert, and a local high-temperature area is constructed; fuel oil is supplied by the oil injection rod, is quickly evaporated in the evaporation pipe, is uniformly sprayed out from the exhaust hole of the evaporation pipe, and enters a backflow area at the tail part of the stabilizer to be combusted. Inner and outer culvert airflow mixing and local high-temperature area construction can be completed in the tail backflow area of the stabilizer, and the high evaporation degree and uniform distribution of fuel oil are guaranteed. Therefore, stable combustion and high-success-rate ignition in a wide working range under multi-mode working of the variable-cycle engine can be achieved.

Description

Technical Field

[0001] The present application relates to the technical field of afterburner combustion chambers of adaptive variable cycle aircraft engines, and in particular to a premixed preevaporation type flame stabilizer with an evaporation tube. Background Art

[0002] In order to meet the requirements of large flight envelope, long range, multi-mission capability and other requirements of future aircraft, the next generation of aircraft engines need to have the ability to realize a variety of different thermodynamic cycles. However, traditional single-cycle turbojet and turbofan engines can no longer meet these complex requirements. In this context, in order to meet the performance requirements of aircraft engines for various missions and environmental characteristics, variable cycle engines (VCE) with flexible variable components have emerged and become a very attractive future aircraft engine solution.

[0003] Afterburner is an important component in aircraft engines, which can greatly improve the engine thrust-to-mass ratio and expand the flight envelope. At present, most VCE schemes adopt afterburner configuration. Traditional turbofan engines usually have the characteristics of fixed bypass ratio, and the inlet conditions of their afterburner are relatively simple. However, variable cycle engines (VCE) need to maintain stable and reliable operation within a wide bypass ratio range of 0.2 to 1.0 (that is, the inlet Mach number is within the range of 0.15 to 0.45). The drastic changes in the bypass flow parameters outside the afterburner cause the traditional afterburner scheme to no longer be applicable to the VCE scheme. A new design scheme is urgently needed to meet the ignition and flame stability capabilities under wide flow conditions.

[0004] Based on the above technical problems, researchers have proposed improvement plans for the flame stabilizer in the afterburner. For example, Chinese patent CN115451430A discloses a premixed preevaporation flame stabilizer and Chinese patent CN116293793A discloses an external flame stabilizer, a rear duct variable area ejector and an afterburner. Both of these improvement plans adopt the technical solution of coupling the stabilizer with the diverter ring and setting a channel to introduce the internal gas. Under the working conditions of the afterburner of a variable cycle engine, these two improvement plans can improve the fuel atomization effect, increase the temperature of the oil-gas mixture and improve the ignition performance. However, research has found that these two improvement schemes still have defects: on the one hand, the stabilizer's on-duty oil supply is directly sprayed into the air flow channel, the fuel stays in the stabilizer for a short time, and the low-temperature inlet temperature is lower than the initial distillation point of the fuel, which makes the fuel evaporation degree very low. The stabilizer can only achieve two-phase combustion dominated by oil droplets, and the oil droplets will be deposited on the wall, increasing the difficulty of ignition, and ultimately manifesting as unstable combustion of the flame stabilizer; on the other hand, the internal combustion gas introduced into the flame stabilizer is directly sprayed axially into the tail recirculation zone through the outlet channel, which destroys the stability of the recirculation zone and increases the probability of flameout of the flame stabilizer, making it difficult to cope with the extreme working conditions of VCE. Summary of the invention

[0005] In response to the above technical problems, the present invention provides a premixed preevaporation type flame stabilizer with an evaporation tube, which can increase the fuel residence time, ensure the fuel atomization effect, improve the fuel distribution, shorten the stabilizer length, effectively improve the stability and width of the recirculation zone behind the stabilizer, and better adapt to the wide bypass ratio working characteristics of the variable cycle engine.

[0006] The present invention provides a premixing preevaporation type flame stabilizer with an evaporation tube, which comprises:

[0007] An air intake ring is arranged inside the diverter ring and forms an air intake passage with the diverter ring;

[0008] an inner stabilizer, arranged outside the intake ring and extending outward to the outside of the diverter ring, comprising an inner front wall surface and an inner side wall surface;

[0009] an outer stabilizer, arranged on the outer side of the diverter ring and extending outward to the outer side of the inner stabilizer, comprising an outer upper wall, an outer front wall and an outer side wall, an ascending channel is formed between the outer front wall and the inner front wall, an upper outlet channel is formed between the outer upper wall and the top of the inner stabilizer, and two side outlet channels are formed between the outer side wall and the inner side wall, and the upper outlet channel and the two side outlet channels are connected with the air inlet channel through the ascending channel;

[0010] An evaporation tube is arranged between the air inlet ring and the outer upper wall surface and is located behind the inner stabilizer. The evaporation tube is provided with an air inlet hole and an air outlet hole on its tube wall;

[0011] an air duct, the rear end of which is disposed on the evaporating tube and communicated with the air duct hole, and the front end of which extends into the interior of the ascending channel; and

[0012] The oil spray rod is arranged on the outer side of the diverter ring and extends into the interior of the outer stabilizer to spray oil toward the front end of the air duct.

[0013] Preferably, the inner wall surface and the outer wall surface are parallel to each other, and on a cross section perpendicular to the radial direction, the spacing between the two outer wall surfaces of the outer stabilizer gradually increases axially backward, and the angle between the outer wall surface and the axial direction is 12° to 20°.

[0014] Preferably, the width of the trailing edge of the outer stabilizer is greater than 40 mm.

[0015] Preferably, the inner front wall surface and the outer front wall surface are parallel to each other, and in a cross section perpendicular to the circumferential direction, the inner front wall surface and the outer front wall surface are arranged to be inclined outward relative to the axial direction.

[0016] Preferably, the sum of the axial projection areas of the upper outlet channel and the outlet channels on both sides is greater than the axial projection area of ​​the air inlet channel.

[0017] Preferably, the air inlet holes are arranged at the axial front side of the evaporator tube, and the air exhaust holes are arranged at both sides of the evaporator tube in the circumferential direction.

[0018] Preferably, the plurality of exhaust holes are evenly distributed along the length of the evaporator tube, the hole spacing between adjacent exhaust holes is 4 mm to 6 mm, and the total area of ​​the plurality of exhaust holes is 1 to 2.5 times the area of ​​the air introduction holes.

[0019] Preferably, the front end opening of the air duct faces the inner front, and the spray rod is provided with a spray hole, the diameter of the spray hole is 0.4mm to 1mm, the opening direction of the spray hole is 40° to 50° with the axial direction and is directly opposite to the front end opening of the air duct.

[0020] Preferably, the axial distance between the trailing edge of the inner stabilizer and the trailing edge of the outer stabilizer is 10 mm to 25 mm.

[0021] Preferably, the radial dimension of the outer stabilizer is 2 to 4 times the radial distance between the intake ring and the splitter ring.

[0022] Based on the above implementation scheme, the present invention introduces the high-temperature combustion gas and fuel into the evaporation tube for evaporation and atomization, thereby increasing the fuel residence time, improving the fuel atomization degree, and increasing the success rate of the stabilizer lean oil ignition; and because the fuel atomization in the evaporation tube does not require a long intake ring to ensure the fuel atomization time, the present invention can shorten the length of the existing intake ring, reduce the weight of the stabilizer, and improve the engine performance. The present invention also adjusts the internal and external stabilizer structures and controls the angle between the stabilizer wall and the axial direction, thereby widening the size and stability of the stabilizer tail recirculation area, improving the stabilizer's stable working ability under a wide Mach number working range, and can reduce the blockage area of ​​the front end of the stabilizer and avoid the sudden shrinkage of the outer duct airflow channel area, thereby reducing the flow loss caused by the installed stabilizer. Therefore, the present invention can form a recirculation zone that is less affected by the Mach number of the inner and outer sump flows behind the evaporator tube and the inner stabilizer, and the volume of the recirculation zone does not change with the change of the Mach number of the inner and outer sump flows. The fuel is sprayed out from the exhaust hole and is relatively evenly distributed in the recirculation zone, and a local high-concentration fuel distribution zone is formed behind the evaporator tube, which is conducive to successful on-duty ignition under extreme conditions and can ensure the stable ignition capability of the stabilizer under a wide range of outer sump parameter changes in the variable cycle engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application, but do not constitute a limitation on the technical solution of the present application.

[0024] Figure 1 A schematic diagram of the three-dimensional structure of a premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention;

[0025] Figure 2 A schematic diagram of the structure of the premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention from a rear-view angle;

[0026] Figure 3 for Figure 2 A central cross-sectional view of a premixed preevaporation type flame stabilizer with an evaporation tube taken at the middle AA section;

[0027] Figure 4 A schematic diagram of the structure of a premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention from a radially inward perspective;

[0028] Figure 5 A three-dimensional perspective structural diagram of a premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention;

[0029] Figure 6 A schematic diagram of the circumferential cross-sectional flow field structure of the premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention in a fuel-free combustion state;

[0030] Figure 7 A circumferential cross-sectional temperature distribution diagram of the premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention in a fuel-free combustion state;

[0031] Figure 8 The fuel-to-gas ratio distribution diagram of the circumferential section of the premixed preevaporation type flame stabilizer with an evaporation tube provided by the present invention in a fuel-free combustion state.

[0032] Description of reference numerals:

[0033] 1-diverter ring; 2-intake ring; 3-inner stabilizer; 3a-inner front wall; 3b-inner side wall; 4-evaporator tube; 4a-tube wall; 4b-exhaust hole; 4c-intake hole; 5-intake tube; 6-outer stabilizer; 6a-outer upper wall; 6b-outer front wall; 6c-outer side wall; 7-injection rod; 7a-injection hole;

[0034] in-intake channel; up-upward channel; out1-upper outlet channel; out2-outlet channels on both sides. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is not intended to be any limitation on the present invention and its application or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention clear and complete and to fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps described in these embodiments should be interpreted as being merely exemplary and not as a limitation.

[0036] like Figure 1-8 As shown, in order to solve the technical problems in the prior art, the present invention designs a premixed preevaporation flame stabilizer with an evaporation tube, which adds an evaporation tube to improve the atomization and distribution of the fuel, and adjusts the stabilizer structure to improve the stability of the recirculation zone, based on the structure of the premixed preevaporation stabilizer. In order to facilitate the description of the specific structure of the premixed preevaporation flame stabilizer, the present invention establishes a cylindrical coordinate system with the central axis of the aircraft engine as the axis, and the directions X, Y, and Z represent the circumferential, radial (inside and outside directions), and axial (front and back directions) of the cylindrical coordinate system, respectively, and the diverter ring 1 is the dividing line, the inside of the diverter ring 1 is the inner area, and the outside of the diverter ring 1 is the outer area.

[0037] like Figures 1 to 5As shown, the present invention provides a premixed preevaporation type flame stabilizer with an evaporation tube, which is arranged at the rear part of the outer bypass ring 1 in the afterburner, and includes: an intake ring 2 arranged on the inner side of the bypass ring 1; an inner stabilizer 3 arranged on the outer side of the intake ring 2 and extending outward to the outer side of the bypass ring 1; and an outer stabilizer 6 arranged on the outer side of the bypass ring 1 and extending outward to the outer side of the inner stabilizer 3.

[0038] Those skilled in the art can understand that the diverter ring 1 and the intake ring 2 form a double-layer annular structure, and an intake channel in is formed between the diverter ring 1 and the intake ring 2 to guide the high-temperature combustion gas in the afterburner into the premixed preevaporator stabilizer; and the premixed preevaporator flame stabilizer with an evaporator tube provided by the present invention is arranged at the rear of the double-layer annular structure and presents a double-layer shell structure, wherein an ascending channel up is formed between the inner front wall 3a and the outer front wall 6a, and the high-temperature combustion gas introduced by the intake channel in is introduced into the outer duct area through the ascending channel up; an upper outlet channel out1 is formed between the top of the inner stabilizer 3 and the outer upper wall 6a, and two side outlet channels out2 are formed between the inner wall 3b and the outer wall 6c, and the introduced high-temperature combustion gas is ejected through the upper outlet channel out1 and the two side outlet channels out2, enters the axial rear recirculation zone of the premixed preevaporator stabilizer, and is mixed with the low-temperature outer duct air from the outer duct in the recirculation zone, thereby forming a local high-temperature zone in the recirculation zone.

[0039] Based on this structure, the present invention arranges the evaporation pipe 4, the air bleed pipe 5 for supplying air to the evaporation pipe 4, and the oil spray rod 7 for supplying oil behind the inner stabilizer 3 and the outer stabilizer 6. The evaporation pipe 4 is arranged between the intake ring 2 and the outer upper wall 6a and is located behind the inner stabilizer 3; the rear end of the air bleed pipe 5 is arranged on the evaporation pipe 4 and communicates with the air bleed hole 4c, and the front end extends into the interior of the ascending channel; and the oil spray rod 7 is arranged on the outside of the diverter ring 1 and extends into the interior of the outer stabilizer 6, so as to spray oil to the front end of the air bleed pipe 5.

[0040] Among them, the front end of the bleed pipe 5 is located in the ascending channel up to introduce the internal high-temperature gas, and the front end of the bleed pipe 5 also receives the fuel sprayed by the fuel injection rod 7, so that the fuel and the internal high-temperature gas are mixed with each other and enter the evaporation pipe 4 from the bleed pipe 5. The tubular structure of the evaporation pipe 5 can increase the residence time of the fuel to ensure that the fuel is completely evaporated and mixed. The fuel will be evaporated and fully mixed with the internal high-temperature gas in the evaporation pipe 4 under the influence of the internal high-temperature gas. The premixed gas after complete evaporation and mixing is sprayed out from the exhaust hole 4b and enters the low-speed reflux area behind the stabilizer, thereby forming a high-temperature, low-speed, and locally high-fuel concentration reflux area behind the stabilizer, ensuring a high success rate of organizing duty ignition in this area.

[0041] Therefore, the premixed preevaporation flame stabilizer with an evaporation tube provided by the present invention can introduce high-temperature combustion gas into the inner lining, so that a part of the high-temperature combustion gas is ejected from the outlet channel to construct a local high-temperature reflux zone behind the stabilizer, and the other part enters the evaporation tube to assist the fuel atomization in the evaporation tube, thereby increasing the evaporation degree of the fuel, thereby ensuring that the fuel is ejected from the exhaust hole and enters the rear reflux zone to construct a stable ignition zone. Therefore, the present invention forms a stable duty flame in the outer lining, reducing the difficulty of duty ignition under a wide working range of the variable cycle engine. At the same time, the mutual cooperation between the outlet channel airflow and the evaporation tube improves the fuel distribution, so that the fuel is distributed more evenly behind the stabilizer.

[0042] In addition, the present invention utilizes the external stabilizer 6 to separate the interior of the premixed preevaporator stabilizer from the afterburner outer duct airflow: for the outer duct mainstream, the external stabilizer 6 acts as a blunt-body flame stabilizer, and because there is high-temperature combustion gas ejected from the upper outlet channel out1 and the two side outlet channels out2 inside the external stabilizer 6, a low-speed recirculation zone is formed axially rearward of the external stabilizer 6, which will be affected by the internal incoming flow and increase the temperature; for the high-temperature combustion gas ejected from the upper outlet channel out1 and the two side outlet channels out2, since the internal stabilizer 3 is arranged in parallel with the external stabilizer 6, the internal stabilizer 3 acts as a blunt-body flame stabilizer, thereby forming a low-speed recirculation zone behind the internal stabilizer 3, and the low-speed recirculation zone is not affected by the inner and outer duct incoming flows, and thus has better stability.

[0043] Furthermore, in the present invention, only an upper outlet channel out1 and two side outlet channels out2 are provided between the inner stabilizer 3 and the outer stabilizer 6, and the lower outlet channel is eliminated, so as to avoid the internal combustion gas introduced into the flame stabilizer from being directly sprayed into the tail recirculation zone at high speed through the lower outlet channel to destroy the stability of the recirculation zone. Compared with the prior art, the flameout probability of the flame stabilizer is reduced, and it is more adaptable to the extreme working conditions of the VCE.

[0044] Preferably, the inner wall surface 3b and the outer wall surface 6c are parallel to each other, and on a cross section perpendicular to the radial direction, the spacing between the two outer wall surfaces 6c of the outer stabilizer 6 gradually expands axially rearward, and an angle in the range of 12° to 20° is formed between the outer wall surface 6c and the axial direction. Therefore, the present invention improves the width and stability of the axial rear recirculation zone of the stabilizer by adjusting the angle between the side walls of the inner stabilizer and the outer stabilizer and the axial direction, and can ensure that the recirculation zone of the stabilizer is stable under a wide Mach number working range, broaden the working range of the stabilizer, and make it more suitable for the VCE engine; at the same time, this design can reduce the flow loss of the stabilizer under non-afterburner working conditions, thereby improving the engine performance.

[0045] like Figure 4As shown, in a preferred embodiment, the angle between the inner wall surface 3b and the outer wall surface 6c and the axial direction is 18°. On the one hand, this wall tilt design can reduce the blockage area of ​​the front end of the stabilizer and avoid the sudden shrinkage of the outer duct airflow channel area when the trailing edge width remains unchanged, thereby reducing the flow loss caused by the installed stabilizer and reducing the engine working pressure loss under non-afterburner and afterburner conditions; on the other hand, this tilt design can make the airflow direction at the trailing edge of the stabilizer form a certain angle with the axial direction due to the flow direction design tilted to the axial direction when the trailing edge width remains unchanged, thereby widening the size and stability of the recirculation zone at the tail of the stabilizer and increasing the probability of successful ignition in the recirculation zone.

[0046] Preferably, the trailing edge width of the outer stabilizer 6 is greater than 40 mm, thereby ensuring that the circumferential dimension of the flame stabilizer can meet the minimum dimension requirement for stable ignition. The upper limit of the trailing edge width of the outer stabilizer 6 is determined by the overall aerodynamic blockage ratio requirement for the flame stabilizer component.

[0047] Preferably, the inner front wall surface 3a and the outer front wall surface 6a are parallel to each other, and in a cross section perpendicular to the circumferential direction, the inner front wall surface 3a and the outer front wall surface 6a are arranged outwardly with respect to the axial direction. Figure 3 As shown, in a preferred embodiment, the angle between the inner front wall 3a and the outer front wall 6a and the axial direction is 55°. This wall inclination design avoids the sudden shrinkage of the outer flow channel area and reduces the flow loss caused by the stabilizer, thereby reducing the engine working pressure loss under non-boosting conditions and boosting conditions.

[0048] Preferably, the air inlet holes 4c are arranged at the axial front side of the evaporation tube 4, and the exhaust holes 4b are arranged at both sides of the circumference of the evaporation tube 4. The angle between the air inlet holes 4c and the exhaust holes 4b is such that the high-temperature combustion gas entering the evaporation tube 4 through the air inlet holes 4c will not be directly discharged from the exhaust holes 4b, thereby effectively increasing the effective residence time of the high-temperature combustion gas in the evaporation tube 4.

[0049] like Figure 3 As shown, preferably, the plurality of exhaust holes 4b are evenly distributed along the length of the evaporation tube 4, and the hole spacing between adjacent exhaust holes 4b is 4mm to 6mm, so as to ensure the even distribution of the fuel, and the total area of ​​the plurality of exhaust holes 4b is 1 to 2.5 times the area of ​​the air bleed hole 4c, so as to ensure that the premixed fuel gas will not be blocked in the evaporation tube 4. In a preferred embodiment, the hole spacing between adjacent exhaust holes 4b is 5mm, so as to ensure the even distribution of the fuel, and the total area of ​​the plurality of exhaust holes 4b is preferably 2 times or more the area of ​​the air bleed hole 4c, so as to further reduce the speed of the oil-gas mixture discharged from the evaporation tube 4 and improve the reliability of ignition and continuous combustion.

[0050] like Figure 3As shown, preferably, the front end opening of the air bleed pipe 5 faces the inner front (i.e., tilted inward and forward), and a fuel injection hole 7a is opened on the fuel injection rod 7, the diameter of the fuel injection hole 7a is 0.4mm to 1mm, the opening direction of the fuel injection hole 7a is 40° to 50° with the axial direction and is directly opposite to the front end opening of the air bleed pipe 5, so as to ensure that all the fuel can be introduced into the evaporation tube 4 by the air bleed pipe 5. In a preferred embodiment, the diameter of the fuel injection hole 7a is 1mm, and the angle between the fuel injection direction of the fuel injection hole 7a and the axial direction is 45°.

[0051] like Figure 3 As shown, preferably, the axial spacing between the trailing edge of the inner stabilizer 3 and the trailing edge of the outer stabilizer 6 is 10mm to 25mm, so that the outer upper wall 6a and the outer side wall 6c can protect the recirculation zone axially rearward of the stabilizer, avoid the stabilizer recirculation zone being affected under the wide Mach number variation range of the variable cycle engine outer duct, and ensure the reliable duty ignition of the afterburner outer duct under various working conditions of the variable cycle engine. In a preferred embodiment, the axial spacing between the trailing edge of the inner stabilizer 3 and the trailing edge of the outer stabilizer 6 is 15mm.

[0052] Preferably, the sum of the axial projection areas of the upper outlet channel out1 and the two side outlet channels out2 is greater than the axial projection area of ​​the intake channel in, so that the gap between the inner stabilizer 3 and the outer stabilizer 6 is a gradually expanding channel as a whole, so that the airflow of the intake channel in is discharged from the upper outlet channel out1 and the two side outlet channels out2 after being expanded and decelerated, further improving the stability of the recirculation zone and avoiding flow blockage inside the stabilizer.

[0053] Preferably, the radial dimension of the outer stabilizer 6 is 2 to 4 times the radial distance between the intake ring 2 and the diverter ring 1, so as to avoid the outer stabilizer 6 being too large in size, resulting in too high a blockage ratio and excessive aerodynamic resistance, and to prevent the recirculation zone from being unstable due to the outer stabilizer being too small in size, thereby affecting the flame stabilization effect.

[0054] like Figure 6 The figure shows a schematic diagram of the circumferential cross-sectional flow field structure of the premixed preevaporation flame stabilizer with an evaporation tube in the present invention in a fuel-free combustion state. It can be seen from the velocity cloud diagram and streamlines in the figure that the present invention can form a stable recirculation zone behind the stabilizer axially, and generate two upper and lower low-speed vortices in the recirculation zone, wherein the center of the upper low-speed vortex is close to the evaporation tube, and the center of the lower low-speed vortex is at a distance behind the stabilizer axially, and part of the high-temperature combustion gas from the inner lining and part of the low-temperature air from the outer lining are respectively drawn into the recirculation zone by the two low-speed vortices.

[0055] like Figure 7The figure shows the circumferential cross-sectional temperature distribution diagram of the premixed preevaporation type flame stabilizer with evaporation tubes of the present invention in the state of no fuel combustion. It can be seen from the temperature cloud distribution in the figure that the present invention can introduce part of the internal high-temperature fuel gas into the stabilizer and enter the recirculation zone behind the stabilizer through the outlet channel, forming a local high-temperature recirculation zone in the recirculation zone.

[0056] like Figure 8 The figure shows the distribution diagram of the circumferential cross-section fuel-to-gas ratio of the premixed preevaporation flame stabilizer with evaporation tube in the state of no fuel combustion. It can be seen from the distribution of the fuel-to-gas ratio cloud diagram in the figure that after the fuel is sprayed from the fuel injection rod, it enters the evaporation tube and is distributed in the stabilizer reflux area by the evaporation tube, forming a relatively uniform and suitable fuel distribution in the local reflux area. In addition, the fuel is locally enriched at the top of the reflux area, thereby ensuring that under extremely lean fuel conditions, the ignition of the afterburner outer duct stabilizer still maintains a high success rate.

[0057] Based on the technical features in the above specific implementation cases, the beneficial technical effects of the present invention include at least: by introducing the high-temperature combustion gas and fuel into the evaporation tube for evaporation and atomization, the fuel residence time is increased, and the fuel atomization is ensured to be complete, thereby improving the success rate of the stabilizer lean oil ignition, and distributing the fuel through the exhaust holes, so that the fuel distribution can be more uniform; by controlling the inner stabilizer and the outer stabilizer wall surface to maintain a certain angle with the axial direction, the size and stability of the axial rear recirculation area of ​​the stabilizer can be widened, and the blockage area of ​​the front end of the stabilizer can be reduced, and the area of ​​the outer duct air flow channel can be avoided. The fuel oil suddenly decreases, reducing the flow loss caused by the stabilizer; the present invention introduces the evaporator tube auxiliary atomization, which can shorten the length of the intake channel without reducing the degree of fuel atomization, thereby reducing the weight of the stabilizer; behind the evaporator tube and the inner stabilizer, a stable, high-temperature reflux zone that is basically not affected by the incoming flow parameters can be formed, and the fuel is evenly distributed in the reflux zone, forming a local high-concentration fuel zone behind the evaporator tube, ensuring the stable combustion and ignition capabilities of the stabilizer under the wide range of incoming flow parameters of the variable cycle engine, and realizing reliable ignition within the Mach number range of 0.15 to 0.45.

[0058] In summary, the various features and working methods of the present invention have been described in detail through examples, but the above examples do not limit the scope of the present invention. Any simple changes and substitutions made by any technician familiar with the technical field within the technical scope indicated in this application are covered by the protection scope of this application. The scope of the present invention is defined by the attached claims.

Claims

1. A premixed preevaporation type flame stabilizer with an evaporation tube, characterized in that: include: An air intake ring (2) is arranged inside the diverter ring (1) and forms an air intake passage between the diverter ring (1) and the diverter ring (1); An inner stabilizer (3), arranged outside the intake ring (2) and extending outward to the outside of the diverter ring (1), comprising an inner front wall surface (3a) and an inner side wall surface (3b); an outer stabilizer (6), which is arranged on the outer side of the flow dividing ring (1) and extends outward to the outer side of the inner stabilizer (3), and comprises an outer upper wall surface (6a), an outer front wall surface (6b) and an outer side wall surface (6c); an ascending channel is formed between the outer front wall surface (6b) and the inner front wall surface (3a); an upper outlet channel is formed between the outer upper wall surface (6a) and the top of the inner stabilizer (3); and two side outlet channels are formed between the outer side wall surface (6c) and the inner side wall surface (3b); the upper outlet channel and the two side outlet channels are connected to the air inlet channel through the ascending channel; An evaporation tube (4) is arranged between the air inlet ring (2) and the outer upper wall surface (6a) and is located behind the inner stabilizer (3); the evaporation tube (4) is provided with an air inlet hole (4c) and an air outlet hole (4b) on its tube wall (4a); An air duct (5), the rear end of which is arranged on the evaporation tube (4) and communicates with the air duct hole (4c), and the front end of which extends into the interior of the ascending channel; as well as The oil spray rod (7) is arranged on the outside of the diverter ring (1) and extends into the interior of the outer stabilizer (6) to spray oil toward the front end of the air duct (5).

2. The premixed preevaporation type flame stabilizer with an evaporation tube according to claim 1, characterized in that: The inner wall surface (3b) and the outer wall surface (6c) are parallel to each other, and on a cross section perpendicular to the radial direction, the spacing between the two outer wall surfaces (6c) of the outer stabilizer (6) gradually increases axially backward, and the angle between the outer wall surface (6c) and the axial direction is 12° to 20°.

3. The premixed preevaporation type flame stabilizer with evaporation tube according to claim 2, characterized in that: The width of the trailing edge of the outer stabilizer (6) is greater than 40 mm.

4. The premixed preevaporation type flame stabilizer with an evaporation tube according to claim 1, characterized in that: The inner front wall surface (3a) and the outer front wall surface (6a) are parallel to each other, and in a cross section perpendicular to the circumferential direction, the inner front wall surface (3a) and the outer front wall surface (6a) are arranged outwardly and inclined relative to the axial direction.

5. The premixed preevaporation type flame stabilizer with evaporation tube according to claim 1, characterized in that: The sum of the axial projection areas of the upper outlet channel and the outlet channels on both sides is greater than the axial projection area of ​​the air inlet channel.

6. The premixed preevaporation type flame stabilizer with evaporation tube according to claim 1, characterized in that: The air inlet holes (4c) are arranged on the axial front side of the evaporation tube (4), and the air exhaust holes (4b) are arranged on both sides of the circumference of the evaporation tube (4).

7. The premixed preevaporation type flame stabilizer with evaporation tube according to claim 6, characterized in that: The plurality of exhaust holes (4b) are evenly distributed along the length of the evaporator tube (4), the hole spacing between adjacent exhaust holes (4b) is 4 mm to 6 mm, and the total area of ​​the plurality of exhaust holes (4b) is 1 to 2.5 times the area of ​​the air inlet hole (4c).

8. The premixed preevaporation type flame stabilizer with evaporation tube according to claim 1, characterized in that: The front end opening of the air duct (5) faces the inner front, and the fuel injection rod (7) is provided with a fuel injection hole (7a). The diameter of the fuel injection hole (7a) is 0.4 mm to 1 mm. The opening direction of the fuel injection hole (7a) is at an angle of 40° to 50° with the axial direction and is directly opposite to the front end opening of the air duct (5).

9. The premixed preevaporation type flame stabilizer with an evaporation tube according to claim 1, characterized in that: The axial distance between the trailing edge of the inner stabilizer (3) and the trailing edge of the outer stabilizer (6) is 10 mm to 25 mm.

10. The premixed preevaporation type flame stabilizer with an evaporation tube according to claim 1, characterized in that: The radial dimension of the outer stabilizer (6) is 2 to 4 times the radial distance between the intake ring (2) and the splitter ring (1).

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