A fuel oil combined atomizing device applied to a small-size high-temperature-rise combustion chamber

Abstract

The application discloses a fuel oil combined atomizing device applied to a small-size high-temperature rise combustion chamber and relates to the technical field of an aero-engine. The device comprises a first axial swirler, a second axial swirler and a centrifugal nozzle. The first axial swirler and the second axial swirler are coaxially arranged at the head of a flame tube. The centrifugal nozzle is arranged in the first axial swirler. A Venturi tube is further arranged between the second axial swirler and the first axial swirler. A plurality of first oil injection holes and second oil injection holes are arranged on the circumferential outer wall of the Venturi tube. The air passing through the second axial swirler can atomize the fuel oil injected from the first oil injection holes and the second oil injection holes. The device adopts a partitioned pressure oil supply mode, which can meet the requirements of small oil supply flow under conditions such as slow running and large oil supply flow under maximum design conditions such as climbing, and can meet the requirements of high-efficiency combustion on fuel oil atomization quality under different conditions.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of an aero-engine, in particular to a fuel combined atomization device applied to a small-size high-temperature-rise combustion chamber. BACKGROUND

[0002] With the development of aircraft technology, in order to meet the demand for higher thrust-to-weight ratio of engines, the cycle parameters of turbine engines are gradually improved, and the thrust-to-weight ratio target of traditional large engines is gradually increased from 8-10 to 16-20 or even higher. According to relevant research, the engine thrust will increase by 20% for every 100K increase in turbine inlet temperature. The turbine inlet temperature of a typical fourth-generation engine (F119) is increased from 1850K to 2000K, the combustion chamber temperature rise is increased from 1200K to 1350K, and the thrust-to-weight ratio is increased from 10 to 12. As can be seen, developing advanced combustion chamber technology with high temperature rise is an effective method to improve thrust. Compared with traditional large engines, small turbojet engines for small missiles / unmanned aerial vehicles have small structure size and light weight, and it is difficult to realize fuel atomization and combustion organization under the condition of limited space and high oil-gas ratio. The design conclusion of fuel atomization and combustion organization of large engines cannot be simply and directly extrapolated to small turbojet engines.

[0003] High-temperature-rise combustion chamber technology aims to realize efficient and stable combustion under the condition of high oil-gas ratio, and maximize the heat release function of the combustion chamber. For the combustion organization of large engine combustion chambers under the condition of high oil-gas ratio, a multi-stage swirler scheme is usually adopted, the air inlet quantity is increased by increasing the headwind area, and at the same time, the multi-stage swirler air interaction is used to strengthen the fuel atomization and construct a reasonable hot backflow structure. Considering the small structure size, low fuel supply pressure, wide fuel flow, and low cost requirement of small missile / unmanned aerial vehicle engines, the traditional single-oil / double-oil centrifugal nozzle+double-stage swirler fuel atomization technology scheme is no longer applicable to small missile / unmanned aerial vehicle small turbojet engines due to high fuel supply pressure and high cost. With the increase of the thrust-to-weight ratio of small turbojet engines, it is urgent to solve the contradiction between reliable ignition under small working conditions and efficient and stable combustion under large working conditions, and a new fuel atomization method suitable for small-size high-temperature-rise combustion chambers needs to be proposed to reduce the risk of flame instability, combustion oscillation and combustion efficiency reduction of high-temperature-rise combustion chambers.

[0004] In the past, the research on fuel atomization of high-temperature-rise combustion chamber of large engine is mostly designed for nozzle and swirler respectively, and the matching design of the two is also needed. At present, most of the aero-engines use center-mounted nozzle for oil supply. With the increase of oil supply flow, the diameter of the nozzle gradually increases, so the windward area can only be increased by increasing the outer diameter of the swirler. The size of the small turbine engine combustion chamber is small, and the outer diameter of the swirler cannot be greatly increased. Since the high-temperature-rise combustion chamber burns at high oil-gas ratio near the head of the flame tube, even close to the chemical proper combustion, the head of the flame tube will bear high thermal load. In order to prevent the high temperature from causing the Venturi tube to coke, ablate and form carbon, a reasonable active cooling scheme also needs to be considered when designing the fuel atomization device. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the shortcomings in the prior art, and the purpose is to provide a fuel combined atomization device applied to a small-size high-temperature-rise combustion chamber, which adopts a partitioned pressure oil supply mode, takes into account the requirements of small oil supply flow under idle condition and large oil supply flow under maximum design condition such as climbing, and meets the requirements of high-efficiency combustion under different conditions for fuel atomization quality.

[0006] The present application is realized by the following technical scheme:

[0007] A fuel combined atomization device applied to a small-size high-temperature-rise combustion chamber, comprising a first axial swirler, a second axial swirler and a centrifugal nozzle, the first axial swirler and the second axial swirler are coaxially installed at the head of the flame tube, the centrifugal nozzle is located in the first axial swirler, a Venturi tube is further arranged between the second axial swirler and the first axial swirler, a plurality of first oil injection holes and second oil injection holes are arranged on the circumferential outer wall of the Venturi tube, and the airflow passing through the second axial swirler can atomize the fuel injected from the first oil injection holes and the second oil injection holes.

[0008] Further, a first main oil supply channel and a first main oil supply ring are arranged in the Venturi tube, the first main oil supply channel is distributed along the axial direction of the Venturi tube, the first main oil supply channel is in communication with the first main oil supply ring, the first main oil supply ring is distributed in the circumferential direction in the Venturi tube, and the first oil injection holes are in communication with the first main oil supply ring.

[0009] Further, a second main oil supply channel and a second main oil supply ring are arranged in the Venturi tube, the second main oil supply channel is distributed along the axial direction of the Venturi tube, the second main oil supply channel is in communication with the second main oil supply ring, the second main oil supply ring is distributed in the circumferential direction in the Venturi tube, and the second oil injection holes are in communication with the second main oil supply ring.

[0010] Further, the first main oil path and the second main oil path are further arranged between the first axial swirler and the second axial swirler, the first main oil path is communicated with the first main oil supply flow channel, and the second main oil path is communicated with the second main oil supply flow channel.

[0011] Further, the first oil injection hole and the second oil injection hole are arranged in two rows in a circumferential staggered and equidistant manner on the outer wall of the venturi.

[0012] Further, the number of the first oil injection hole and the second oil injection hole is 10-20, and the diameter of the first oil injection hole and the second oil injection hole is 0.3mm-0.6mm.

[0013] Further, the first axial swirler and the second axial swirler are both vane swirler, and the first axial swirler and the second axial swirler are the same or opposite in rotation direction.

[0014] Further, a casing is further included, one end of the casing is provided with a diffuser, and the flame tube is located in the casing.

[0015] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0016] 1. The present application adopts a partitioned pressure supply oil mode, and the fuel nozzle and the air swirler are integrated designed, that is, the geometric structure is simplified, and wide range fuel flow regulation is realized, and different working condition fuel flow demand is adapted;

[0017] 2. The first main oil supply ring and the second main oil supply ring arranged in the venturi can play a role of rectification, and through the front and rear row circumferential staggered and equidistant arrangement of the first oil injection hole and the second oil injection hole, uniform fuel distribution of the combustion chamber and stable combustion can be ensured;

[0018] 3. The present application can reasonably adapt the number and diameter of the first oil injection hole and the second oil injection hole on the outer wall of the venturi, so as to realize the demand of higher fuel flow under low oil pressure regulation, and the universality is stronger;

[0019] 4. The reasonable arrangement of the venturi wall oil injection hole of the present application can take into account the oil supply while cooling the venturi to a certain extent, so as to reduce the risk of venturi coking, ablation and carbon deposition, and the safety and reliability are stronger. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are used to provide further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0021] Figure 1 It is a structural schematic diagram of the high temperature rise combustion chamber of the present application;

[0022] Figure 2 This is a schematic diagram of the structure of the fuel combination atomizing device of the present invention;

[0023] Figure 3 This is a schematic diagram of the fuel combination atomization device of the present invention from another perspective;

[0024] Figure 4 This is a schematic diagram of the fuel combination atomization device of the present invention from another perspective;

[0025] Figure 5 For the present invention Figure 4 Sectional view of BB;

[0026] Figure 6 For the present invention Figure 4 A sectional view of CC.

[0027] The attached diagram shows the markings and corresponding component names:

[0028] 1. Diffuser; 3. Casing; 4. Flame tube; 21. Centrifugal nozzle; 22. First-stage axial cyclone; 23. First main oil passage; 2301. First injection hole; 2302. First main oil passage supply channel; 2303. First main oil passage supply ring; 24. Second main oil passage; 2401. Second injection hole; 2402. Second main oil passage supply channel; 2403. Second main oil passage supply ring; 25. Venturi tube; 26. Second-stage axial cyclone. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example

[0031] like Figures 1 to 6 As shown, the present invention includes a primary axial cyclone separator 22, a secondary axial cyclone separator 26, and a centrifugal nozzle 21. The primary axial cyclone separator 22 and the secondary axial cyclone separator 26 are coaxially mounted on the head of the flame tube 4. The centrifugal nozzle 21 is located inside the primary axial cyclone separator 22. A venturi tube 25 is also provided between the secondary axial cyclone separator 26 and the primary axial cyclone separator 22. The outer circumferential wall of the venturi tube 25 is provided with a plurality of first injection holes 2301 and second injection holes 2401. The airflow passing through the secondary axial cyclone separator 26 can atomize the fuel sprayed from the first injection holes 2301 and the second injection holes 2401 by shearing and carrying.

[0032] The existing technology is mostly used for the center installation of the nozzle for oil supply, with the increase of the oil supply flow, the nozzle diameter gradually increases, so that the windward area can only be increased by increasing the outer diameter of the engine swirler, and the size of the small turbine engine combustion chamber is small, so that the outer diameter of the swirler cannot be greatly increased; at the same time, due to the high temperature combustion of the high temperature combustion chamber near the flame tube head, even close to the chemical proper combustion, the flame tube head will bear high thermal load, so that the venturi in the engine is prone to coking, ablation and carbon deposition and other phenomena, therefore, the technical scheme is additionally provided with a plurality of first oil injection holes 2301 and second oil injection holes 2401 on the outer wall of the venturi 25 between the first axial swirler 22 and the second axial swirler 26, the first oil injection holes 2301 and the second oil injection holes 2401 are independent of each other for oil supply, so that the present atomization device adopts a partitioned pressure oil supply mode, taking into account the small oil supply flow under the condition of slow vehicle and the oil supply flow under the maximum design condition of climbing, while meeting the requirements of high efficiency combustion for fuel atomization quality under different conditions, the technical scheme adopts the overall layout scheme of integrating the centrifugal nozzle 21 and the air swirler, wherein the standby area adopts a single oil path centrifugal nozzle 21 for oil supply, and the main oil area adopts the first oil injection hole 2301 and the second oil injection hole 2401 for oil supply, so that when the air passes through the first oil injection hole 2301 and the second oil injection hole 2401, the fuel injected from the first oil injection hole 2301 and the second oil injection hole 2401 is well atomized by relying on the transverse aerodynamic force of the air, reducing the demand of fuel atomization on oil supply pressure.

[0033] At the same time, the oil supply channels of the first oil injection hole 2301 and the second oil injection hole 2401 in the technical scheme are integrated in the inside of the venturi 25, so that when the fuel passes through the oil supply channel located in the venturi 25, the fuel can exchange heat with the venturi 25, so as to achieve the purpose of cooling the venturi 25 to a certain extent, thereby reducing the risk of coking, ablation and carbon deposition of the venturi 25, so that the technical scheme solves the problems of low oil supply pressure, wide fuel flow regulation range and limited structure size of the existing small turbine jet engine, and effectively cools the venturi by using the outflow characteristics of the first oil injection hole 2301 and the second oil injection hole 2401 distributed on the venturi 25.

[0034] The principle of the tool of the present application is that when the small bomb or unmanned aerial vehicle starts, the controller sends an ignition instruction to start the motor, and under the driving of the compressor, compressed air enters the swirler from the head of the flame tube, at the same time, the oil mist cone flows to the outlet of the venturi 25 under the air carrying of the first-stage axial swirler 22, and then is strengthened by the reverse swirling air of the second-stage axial swirler 26, and a recirculation zone is constructed in the main combustion zone, the recirculation zone absorbs the intake air of the main combustion hole to participate in further mixing, the igniter is powered to strike a spark, ignites the oil-gas mixture near the nozzle outlet, and under the action of the recirculation zone, a stable standing pilot flame is formed by flame transmission.

[0035] When the small bomb or unmanned aerial vehicle cruises, the controller sends an oil supplement instruction, at this time, the first main oil way 23 gradually supplies oil, the combustion of the main combustion zone rich in oil increases the speed of the compressor, thereby increasing the intake air of the head of the flame tube, the increase of the intake air of the head of the flame tube not only strengthens the atomization of the fuel sprayed from the first fuel injection hole 2301, but also increases the size of the recirculation zone in the main combustion zone, enhances the effect of the recirculation zone on the intake air of the main combustion hole, and enhances the oil-gas mixing, thereby further increasing the combustion efficiency, increasing the temperature of the combustion chamber, and further increasing the temperature rise of the combustion chamber.

[0036] When the small bomb or unmanned aerial vehicle cruises, the controller sends an oil supplement instruction, at this time, the first main oil way 23 gradually supplies oil, the combustion of the main combustion zone rich in oil increases the speed of the compressor, thereby increasing the intake air of the head of the flame tube, the increase of the intake air of the head of the flame tube not only strengthens the atomization of the fuel sprayed from the first fuel injection hole 2301, but also increases the size of the recirculation zone in the main combustion zone, enhances the effect of the recirculation zone on the intake air of the main combustion hole, and enhances the oil-gas mixing, thereby further increasing the combustion efficiency, increasing the temperature of the combustion chamber, and further increasing the temperature rise of the combustion chamber.

[0037] The venturi 25 is provided with a first main oil way oil flow channel 2302 and a first main oil way oil supply ring 2303, the first main oil way oil flow channel 2302 is distributed along the axis of the venturi 25, and the first main oil way oil flow channel 2302 communicates with the first main oil way oil supply ring 2303, the first main oil way oil supply ring 2303 is distributed in the venturi 25 in the circumferential direction, and the first fuel injection hole 2301 communicates with the first main oil way oil supply ring 2303.

[0038] In order to ensure that the independent fuel is sprayed from the first fuel injection hole 2301 on the venturi 25, a first main oil supply flow channel 2302 and a first main oil supply ring 2303 are arranged in the venturi 25. The first main oil supply ring 2303 is circumferentially distributed in the venturi 25. This design not only enables the plurality of first fuel injection holes 2301 on the circumferential direction of the venturi 25 to be in communication with the first main oil supply ring 2303, but also enables the first main oil supply ring 2303 in the annular structure to increase the contact area of the fuel with the venturi 25, thereby improving the cooling effect of the fuel on the venturi 25.

[0039] The venturi 25 is provided with a second main oil supply flow channel 2402 and a second main oil supply ring 2403. The second main oil supply flow channel 2402 is axially distributed along the venturi 25, and the second main oil supply flow channel 2402 is in communication with the second main oil supply ring 2403. The second main oil supply ring 2403 is circumferentially distributed in the venturi 25, and the second fuel injection hole 2401 is in communication with the second main oil supply ring 2403.

[0040] Similarly, in order to ensure that the independent fuel can be sprayed from the first fuel injection hole 2301 on the venturi 25, the second main oil supply flow channel 2402 and the second main oil supply ring 2403 are also arranged in the venturi 25. The second main oil supply flow channel 2402 and the second main oil supply ring 2403 are not connected with the first main oil supply flow channel 2302 and the first main oil supply ring 2303, thereby ensuring the independence between the first fuel injection hole 2301 and the second fuel injection hole 2401.

[0041] Preferably, the second main oil supply flow channel 2402 and the first main oil supply flow channel 2302 are respectively located on the two sides of the axial direction of the venturi 25. In this way, the fuel in the second main oil supply flow channel 2402 and the first main oil supply flow channel 2302 can respectively exchange heat with different positions of the venturi 25, thereby achieving the purpose of uniformly cooling the venturi 25.

[0042] Preferably, the inner diameter of the first main oil supply ring 2303 is smaller than the inner diameter of the second main oil supply ring 2403, thereby ensuring that the first main oil supply ring 2303 and the second main oil supply ring 2403 are located at different radial directions of the venturi 25, and avoiding the intersection of the first main oil supply ring 2303 and the second main oil supply ring 2403.

[0043] The first main oil supply flow channel 2302 is in communication with the first main oil supply flow channel 2302, and the second main oil supply flow channel 2402 is in communication with the second main oil supply flow channel 2402.

[0044] The first main oil path 23 and the second main oil path 24 are respectively connected with the fuel pump of the engine, and fuel can be independently delivered into the first main oil path 23 and the second main oil path 24 by the fuel pump, so that the fuel can be sprayed from the first oil injection hole 2301 and the second oil injection hole 2401.

[0045] The first oil injection hole 2301 and the second oil injection hole 2401 are circumferentially staggered and equidistantly distributed in two rows on the outer wall of the venturi 25.

[0046] In order to reduce the mutual influence between the first oil injection hole 2301 and the second oil injection hole 2401 and improve the atomization effect of the fuel, the first oil injection hole 2301 and the second oil injection hole 2401 are circumferentially staggered in the embodiment, and the first oil injection hole 2301 and the second oil injection hole 2401 are located on different axial directions of the venturi 25, so that the first oil injection hole 2301 and the second oil injection hole 2401 are distributed in front and back, which ensures that the fuel can be uniformly sprayed from the surface of the venturi 25, and the rotational flow air generated by the secondary axial flow device 26 is used to shear and carry the sprayed fuel to the combustion area, so as to realize the full atomization of the fuel.

[0047] The circumferential staggered arrangement of the first oil injection hole 2301 and the second oil injection hole 2401 in front and back rows effectively reduces the interaction of the oil injection holes in front and back rows, so that the fuel sprayed from the second oil injection hole 2401 can still be subjected to sufficient aerodynamic force, thereby strengthening the atomization effect.

[0048] The number of the first oil injection hole 2301 and the second oil injection hole 2401 is 10-20, and the diameter of the first oil injection hole 2301 and the second oil injection hole 2401 is 0.3mm-0.6mm.

[0049] Preferably, the diameter and number of the first oil injection hole 2301 and the second oil injection hole 2401 on the surface of the venturi 25 can be reasonably matched to meet the demand of higher fuel flow under low oil pressure.

[0050] The primary axial flow device 22 and the secondary axial flow device 26 are both vane type flow devices, and the primary axial flow device 22 and the secondary axial flow device 26 have the same or opposite rotation directions.

[0051] The primary axial flow device 22 and the secondary axial flow device 26 provided in the embodiment are both prior art, and both adopt vane type flow devices.

[0052] Further comprising a casing 3, one end of the casing 3 is provided with a diffuser 1, and the flame tube 4 is located in the casing 3.

[0053] The centrifugal nozzle 21 in the technical scheme is a low-pressure fuel atomizing nozzle. When the engine starts, the controller sends an ignition instruction. The air from the diffuser 1 enters the first axial swirler 22 through the head of the flame tube 4. At the same time, the centrifugal nozzle 21 in the central value service area supplies oil. The oil mist cone flows to the outlet of the Venturi tube 25 under the carrying of the first axial swirler 22. Then, the air flowing out of the second axial swirler 26 impacts the first swirler air, strengthens atomization, and constructs a reasonable heat backflow area. Then, the oil-gas mixture near the nozzle outlet is ignited to form a stable value service flame under the action of the backflow area.

[0054] The above detailed description further describes the purpose, technical scheme and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A combined fuel oil atomizing device for small size high temperature rise combustion chamber, characterized in that, The application relates to a combustion chamber, which comprises a primary axial cyclone (22), a secondary axial cyclone (26) and a centrifugal nozzle (21), the primary axial cyclone (22) and the secondary axial cyclone (26) are coaxially arranged at the head of a flame tube (4), the centrifugal nozzle (21) is arranged in the primary axial cyclone (22), a Venturi tube (25) is further arranged between the primary axial cyclone (22) and the secondary axial cyclone (26), a plurality of first fuel injection holes (2301) and second fuel injection holes (2401) are arranged on the circumferential outer wall of the Venturi tube (25), and airflow passing through the secondary axial cyclone (26) can atomize fuel injected from the first fuel injection holes (2301) and the second fuel injection holes (2401). The Venturi tube (25) is provided with a first main oil supply channel (2302) and a first main oil supply ring (2303), the first main oil supply channel (2302) is axially arranged on the Venturi tube (25), the first main oil supply channel (2302) is communicated with the first main oil supply ring (2303), the first main oil supply ring (2303) is circumferentially arranged in the Venturi tube (25), and the first fuel injection holes (2301) are communicated with the first main oil supply ring (2303). The Venturi tube (25) is provided with a second main oil supply channel (2402) and a second main oil supply ring (2403), the second main oil supply channel (2402) is axially arranged on the Venturi tube (25), the second main oil supply channel (2402) is communicated with the second main oil supply ring (2403), the second main oil supply ring (2403) is circumferentially arranged in the Venturi tube (25), and the second fuel injection holes (2401) are communicated with the second main oil supply ring (2403). The first main oil supply channel (2302) is communicated with a first main oil supply channel (23), and the second main oil supply channel (2402) is communicated with a second main oil supply channel (24). The first fuel injection holes (2301) and the second fuel injection holes (2401) are arranged in two rows on the outer wall of the Venturi tube (25) in a circumferentially staggered and equidistant manner.

2. The fuel combined atomizing device for small size high temperature rise combustion chamber according to claim 1, characterized in that, The number of the first fuel injection holes (2301) and the second fuel injection holes (2401) is 10-20, and the diameter of the first fuel injection holes (2301) and the second fuel injection holes (2401) is 0.3mm-0.6mm.

3. The fuel combined atomizing device for small size high temperature rise combustion chamber according to claim 1, characterized in that, The primary axial cyclone (22) and the secondary axial cyclone (26) are both vane type cyclones, and the primary axial cyclone (22) and the secondary axial cyclone (26) have the same or opposite rotation directions.

4. The fuel combined atomizing device for small size high temperature rise combustion chamber according to claim 1, characterized in that, The application further relates to a machine casing (3), one end of the machine casing (3) is provided with a diffuser (1), and the flame tube (4) is arranged in the machine casing (3).

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