Combustion chamber head structure

Abstract

The present invention relates to a combustion chamber head structure, including a swirler assembly and a splash plate; the swirler assembly and the splash plate form a fan-shaped combustion chamber unit, and a plurality of fan-shaped combustion chamber units form an annular combustion chamber; the swirler assembly is located at the center of the fan-shaped area of ​​the combustion chamber unit, and the swirler assembly is composed of a first oil supply system, a primary swirler, a secondary swirler and a venturi; the splash plate is connected to the periphery of the swirler assembly and is connected to an inner ring flame tube and an outer ring flame tube; a second oil supply system is provided on the outer side of the splash plate, and an outer channel, a transition channel, an inner channel, an oil outlet hole and an air hole for the fuel are provided inside the splash plate. The beneficial effects of the present invention are as follows: the present invention promotes the uniform distribution of the main fuel in the circumferential direction of the outer side of the swirler assembly through the drainage of the outer channel, the transition channel and the inner channel inside the splash plate, and the uniform distribution of the oil outlet holes can improve the uniformity of the main combustion oil output, and avoid the occurrence of local combustion hot spots in the main combustion stage.

Description

Technical Field

[0001] The invention relates to a combustion chamber head structure and belongs to the field of aviation engines and gas turbines. Background Art

[0002] The aircraft engine is the heart of the aircraft. It is not only the power source for the aircraft to fly, but also an important driving force for the development of aviation. In order to meet the combat requirements of high-speed maneuvers, modern high-performance fighters have higher and higher thrust-to-weight ratios for engines. The engine cycle parameters are also constantly improving, with the total increase ratio reaching more than 40, and the combustion chamber inlet and outlet temperature rise reaching more than 1100K.

[0003] The combustion chamber is the core component of the engine, which is used to convert the chemical energy in the fuel into thermal energy. The increase in the temperature rise of the combustion chamber inlet and outlet will inevitably lead to an increase in the oil-gas ratio of the combustion chamber. The combustion chamber is in a high temperature, high pressure, and high stress environment for a long time. The increase in the oil-gas ratio is very likely to cause faults such as guide plate ablation and head wall ablation, which directly makes it difficult for the engine to work normally.

[0004] Since the high-temperature combustion gas generated during the combustion of fuel oil will damage and ablate the wall of the combustion chamber head, it is very important to cool the wall of the combustion chamber head. At present, the conventional implementation scheme mainly achieves wall cooling by setting a guide plate to control the flow of cooling air. However, the guide plate is generally located in the main combustion zone, and the combustion temperature is very high, which can easily damage the guide plate, resulting in poor cooling effect and high cost. Figure 4 As shown, the combustion chamber includes a combustion chamber head 101 , a flame tube 102 and a guide plate 103 .

[0005] Patent CN109899831A not only eliminates the guide plate by setting a fuel cavity on the splash plate and an oil outlet at the sleeve position, but also reduces the temperature of the splash plate by absorbing heat from the fuel and absorbing heat from vaporization. However, this patent has the following problems: (1) The splash plate and the swirler are processed as a whole, which increases the process difficulty and processing cost; (2) The cavity does not have any guide or rectifying device, which can easily cause uneven fuel distribution, and then cause uneven circumferential oil discharge from the oil outlet, forming a local combustion hotspot; (3) The fuel entering the flame tube from the outlet hole may affect the fuel entering from the nozzle 8, and the two-stage flames interfere with each other. Figure 5 As shown, it includes: a combustion chamber head 1, a flame tube 2, a splash plate 3, a cavity 31, a first-stage oil supply system 4, an oil outlet 5, a first-stage vortex generator 6, a second-stage vortex generator 7, and a nozzle 8. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a combustion chamber head structure.

[0007] The combustion chamber head structure includes a swirler assembly and a splash plate; the swirler assembly and the splash plate form a fan-shaped combustion chamber unit, and a plurality of fan-shaped combustion chamber units form an annular combustion chamber; the swirler assembly is located at the center of the fan-shaped area of ​​the combustion chamber unit, and the swirler assembly is composed of a first oil supply system, a first-stage swirler, a second-stage swirler and a venturi; the splash plate is connected to the outer periphery of the swirler assembly and is connected to the inner ring flame tube and the outer ring flame tube; the second oil supply system is provided on the outer side of the splash plate, and the outer channel, transition channel, inner channel, oil outlet hole and air hole of the fuel are provided inside the splash plate; The outer channel is located at the edge of the splash plate away from the center, and the outer side of the outer channel is connected to the second oil supply system; the inner channel is located near the center of the splash plate, the inner channel is a circular structure, and an oil outlet is provided on the side of the inner channel away from the head of the combustion chamber; the transition channel is provided between the outer channel and the inner channel, the outer channel, the transition channel and the inner channel are connected to each other, and the transition channel is arranged in a fan-blade shape on the outer periphery of the inner channel, and the transition channel has a certain angle relative to the inner channel; the air hole is provided on the inner side of the inner channel, and the air hole passes through the splash plate.

[0008] Preferably, the center of the cyclone assembly is the first oil supply system, a primary cyclone is arranged outside the first oil supply system, a secondary cyclone is arranged outside the primary cyclone, and a venturi is arranged inside the primary cyclone.

[0009] As a preference: the axial wall thickness of the splash plate is 2-4 mm,

[0010] Preferably, the axial width of the fuel channel inside the splash plate is 1-3 mm.

[0011] Preferably, the sector-shaped combustion chamber units are connected to each other through outer channels.

[0012] Preferably, a plurality of transition channels are arranged in each sector-shaped combustion chamber unit, and the distribution positions of the transition channels are centrally symmetrical with respect to the swirler assembly.

[0013] Preferably, the diameter of the oil outlet holes is 0.5-2 mm, and they are evenly distributed in the circumferential direction, and the interval between two adjacent oil outlet holes is 5°-36°.

[0014] Preferably, the diameter of the air holes is 0.5-3 mm, they are evenly distributed in the circumferential direction, and the interval between two adjacent air holes is 5°-36°.

[0015] Preferably, the axis of the air hole forms an acute angle with the axis of the oil outlet hole.

[0016] Preferably, the number of the air holes and the number of the oil outlet holes are in multiple relation.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention promotes the uniform distribution of the main fuel in the circumferential direction of the outer side of the swirler assembly through the drainage of the outer channel, the transition channel and the inner channel inside the splash plate. The uniform distribution of the oil outlet holes can improve the uniformity of the main combustion oil output and avoid the occurrence of local combustion hot spots in the main combustion stage.

[0019] 2. The present invention eliminates the setting of the guide plate. The splash plate is located in the high-temperature area of ​​the main combustion zone. By setting the fuel flow channel, the fuel in the cavity absorbs heat from the wall of the splash plate to increase the temperature and vaporize, while reducing the wall temperature of the splash plate to prevent the splash plate from being burned.

[0020] 3. The present invention is provided with air holes and oil outlet holes. The fuel in the main combustion stage is vaporized to form fuel vapor, which is mixed with the air entering from the air holes to form semi-premixed combustion. The combustion temperature is low and NO x Emissions are reduced; and because fuel and air are located in separate outlets, there is no risk of backfire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the longitudinal section of a sector-shaped combustion chamber unit;

[0022] Figure 2 for Figure 1 Schematic diagram of the middle AA section;

[0023] Figure 3 It is a schematic diagram of the cross section of the full annular combustion chamber;

[0024] Figure 4 It is a structural schematic diagram of the existing conventional technical solution;

[0025] Figure 5 It is a schematic diagram of the structure of the implementation scheme of patent CN109899831A.

[0026] Explanation of the reference numerals: 1. cyclone assembly; 11. first oil supply system; 12. primary cyclone; 13. venturi; 14. secondary cyclone; 15. sleeve; 2. splash plate; 21. second oil supply system; 22. outer channel; 23. transition channel; 24. inner channel; 25. air hole; 26. oil outlet hole; 3. inner ring flame tube; 4. outer ring flame tube. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0028] As an embodiment, the combustion chamber head structure is such that part of the airflow from the combustion chamber inlet enters the flame tube from the combustion chamber head, and the other part enters the flame tube from the openings on the inner ring flame tube 3 and the outer ring flame tube 4. Among them, the air entering from the combustion chamber head enters the flame tube from the first-stage swirler 12, the second-stage swirler 14 and the air hole 25 respectively. The combustion chamber head structure includes a swirler assembly 1 and a splash plate 2. The swirler assembly 1 and the splash plate 2 form a fan-shaped combustion chamber unit, and a plurality of fan-shaped combustion chamber units form an annular combustion chamber. The swirler assembly 1 is located at the center of the fan-shaped area of ​​the combustion chamber unit, and the splash plate 2 is connected to the outer periphery of the swirler assembly 1 and is connected to the inner ring flame tube 3 and the outer ring flame tube 4. The center of the cyclone assembly 1 is a first oil supply system 11, a first-stage cyclone 12 is arranged outside the first oil supply system 11, a second-stage cyclone 14 is arranged outside the first-stage cyclone 12, a venturi tube 13 is arranged inside the first-stage cyclone, and the first oil supply system 11 can form a pre-combustion stage diffusion flame with the airflow flowing through the first and second-stage cyclones. A second oil supply system 21 is provided on the outside of the splash plate 2, and an outer channel 22, a transition channel 23, an inner channel 24, an oil outlet 26 and an air hole 25 of the fuel are provided inside the splash plate 2; the outer channel 22 is located at the inner edge of the splash plate 2, and the outer side of the outer channel 22 is connected to the second oil supply system 21; the inner channel 24 is located near the center of the splash plate 2, the inner channel 24 is annular, and an oil outlet 26 is provided on the side of the inner channel 24 away from the head of the combustion chamber for fuel vapor injection; the transition channel 23 is provided between the outer channel 22 and the inner channel 24, and is used to connect the outer channel 22 and the inner channel 24, and the transition channel is arranged in the shape of a fan blade on the outer periphery of the inner channel 24, and the transition channel 23 has a certain angle relative to the inner channel 24, and is used to form a circumferential movement of the fuel so that it can flow out evenly from the oil outlet; the air hole 25 is provided on the inner side of the inner channel 24 and passes through the splash plate 2, and the air coming in from the head of the combustion chamber can directly enter the flame tube through the air hole 25.

[0029] The outer channel 22, transition channel 23 and inner channel 24 form a carefully arranged cavity inside the splash plate 2. The fuel sprayed by the second fuel supply system 21 passes through the outer channel 22, transition channel 23 and inner channel 24 inside the splash plate 2, and flows out from the oil outlet 26 evenly, so as to avoid the formation of local hot spots in the combustion chamber as much as possible. Since the splash plate is located in the high-temperature area of ​​the main combustion zone, the fuel in the cavity can absorb the heat from the wall of the splash plate and vaporize, thereby reducing the surface temperature of the splash plate. The density and viscosity of the vaporized fuel are reduced, and it can form a semi-premixed flame of the main combustion stage with the air flowing out of the air hole. At the same time, since the axial direction of the air hole 25 and the oil outlet hole 26 is at an acute angle, the mutual mixing between the air and the fuel vapor can be strengthened, making the oil and gas mixing more uniform. It not only reduces the combustion temperature and reduces NO x Emissions can also effectively avoid backfire problems.

[0030] As a preferred embodiment, the wall thickness of the splash plate 2 may be 2-4 mm, and the axial width of the hollow cavity (fuel channel) in the splash plate 2 may be 1-3 mm.

[0031] As a preferred embodiment, the outer channel 22 inside the splash plate is of irregular shape, and the outer side is connected to the second oil supply system 21, and different sector-shaped combustion chamber units are connected to each other.

[0032] As a preferred embodiment, a plurality of transition passages may be arranged in a single sector-shaped combustion chamber unit, and the distribution positions are centrally symmetrical with respect to the swirler assembly 1 .

[0033] As a preferred embodiment, the oil outlet holes 26 inside the splash plate have a diameter of 0.5-2 mm and are evenly distributed in the circumferential direction, and the interval between two adjacent oil outlet holes 26 is 5°-36°; the air holes 25 have a diameter of 0.5-3 mm and are evenly distributed in the circumferential direction, and the interval between two adjacent air holes 25 is 5°-36°; the axis of the air holes forms an acute angle with the axis of the oil outlet holes to enhance the mixing between the fuel and the air; the number of air holes and oil outlet holes is in a multiple relationship.

Claims

1. A combustion chamber head structure, characterized in that: The invention comprises a swirler assembly (1) and a splash plate (2); the swirler assembly (1) and the splash plate (2) form a sector-shaped combustion chamber unit, and a plurality of sector-shaped combustion chamber units form an annular combustion chamber; the swirler assembly (1) is located at the center of the sector-shaped region of the combustion chamber unit, and the swirler assembly (1) is composed of a first oil supply system (11), a first-stage swirler (12), a second-stage swirler (14) and a venturi (13); the splash plate (2) is connected to the outer periphery of the swirler assembly (1) and is connected to an inner ring flame tube (3) and an outer ring flame tube (4); a second oil supply system (21) is provided on the outer side of the splash plate (2), and an outer channel (22), a transition channel (23), an inner channel (24), an oil outlet hole (26) and an air hole (25) of fuel oil are provided inside the splash plate (2); the outer channel (22) is located at an edge position away from the center inside the splash plate (2), and the outer side of the outer channel (22) is connected to the second oil supply system (21). The inner channel (24) is located near the center of the splash plate (2), the inner channel (24) is a circular ring structure, and an oil outlet hole (26) is provided on the side of the inner channel (24) away from the combustion chamber head; the transition channel (23) is provided between the outer channel (22) and the inner channel (24), the outer channel (22), the transition channel (23) and the inner channel (24) are interconnected, and the transition channel (23) is arranged in a fan-blade shape on the outer periphery of the inner channel (24), and the transition channel (23) has a certain angle relative to the inner channel (24); the air hole (25) is provided on the inner side of the inner channel (24), and the air hole (25) passes through the splash plate (2); the sector-shaped combustion chamber units are interconnected through the outer channel (22); a plurality of transition channels (23) are provided in each sector-shaped combustion chamber unit, and the distribution position of the transition channels (23) is in a centrally symmetrical form relative to the swirler assembly (1).

2. The combustion chamber head structure according to claim 1, characterized in that: The center of the cyclone assembly (1) is a first oil supply system (11), a first-stage cyclone (12) is arranged outside the first oil supply system (11), a second-stage cyclone (14) is arranged outside the first-stage cyclone (12), and a venturi tube (13) is arranged inside the first-stage cyclone.

3. The combustion chamber head structure according to claim 1, characterized in that: The axial wall thickness of the splash plate (2) is 2-4 mm.

4. The combustion chamber head structure according to claim 1, characterized in that: The axial width of the fuel channel inside the splash plate (2) is 1-3 mm.

5. The combustion chamber head structure according to claim 1, characterized in that: The diameter of the oil outlet holes (26) is 0.5-2 mm, and they are evenly distributed in the circumferential direction. The interval between two adjacent oil outlet holes (26) is 5°-36°.

6. The combustion chamber head structure according to claim 1, characterized in that: The diameter of the air holes (25) is 0.5-3 mm, and they are evenly distributed in the circumferential direction. The interval between two adjacent air holes (25) is 5°-36°.

7. The combustion chamber head structure according to claim 1, characterized in that: The axis of the air hole forms an acute angle with the axis of the oil outlet hole.

8. The combustion chamber head structure according to claim 1, characterized in that: The number of air holes and oil outlet holes is in multiple relation.

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