Composite cooled combustion chamber structure

Abstract

The composite cooling combustion chamber structure of the present application, the flame tube comprises an inner ring and an outer ring, the flame tube head is provided with an oil supply oil path of a nozzle, characterized in that the outer ring is provided in a double-layer structure and is formed with a cooling structure capable of cooling the outer ring. Since the present application only uses a small amount of cooling gas, most of the air enters the flame tube head, ensuring sufficient combustion distance in the flame tube for full combustion of the fuel, effectively widening the temperature rise range of the combustion chamber, adopting an oil-gas-water composite cooling mode to ensure the high-temperature operation safety of the flame tube and improve the engine thrust to a certain extent.

Description

Technical Field

[0001] This invention relates to the technical field of cooling structures for aircraft engine walls, and more particularly to a composite cooling combustion chamber structure. Background Technology

[0002] With the increasing thrust-to-weight ratio of aero-engines, the design of combustion chamber components is continuously evolving towards higher temperature rise and higher heat capacity. Consequently, the temperature of the air entering the combustion chamber from the compressor is constantly rising, and the amount of combustion air entering the flame tube head is continuously increasing. This leads to a significant reduction in the amount of air used for mixing and wall cooling, and a certain degree of increase in the initial temperature of the cooling air, resulting in a decrease in cooling potential. To improve the service life of high-temperature components, while ensuring combustion performance and operational reliability, designing and developing a combustion chamber wall cooling structure with a low cooling air ratio and high cooling efficiency is crucial. Summary of the Invention

[0003] In view of this, the present invention provides a composite cooling combustion chamber structure that, through an oil-gas-water composite cooling method, achieves the requirement that the combustion chamber wall temperature can be reduced to below the long-term allowable temperature of the material with only a small amount of cooling gas involved, thus ensuring the service life of the combustion chamber under high-temperature flames.

[0004] A composite cooling combustion chamber structure is provided for cooling the wall of a flame tube. The flame tube includes an inner ring and an outer ring. The flame tube head is provided with an oil supply passage for the nozzle. The outer ring is provided with a double-layer structure and has a cooling structure that can cool the outer ring.

[0005] Beneficial effects

[0006] This invention uses only a small amount of cooling air, with most of the air entering the head of the flame tube, ensuring sufficient combustion distance within the flame tube for complete fuel combustion. This effectively widens the temperature rise range of the combustion chamber. The use of an oil-air-water composite cooling method ensures safe high-temperature operation of the flame tube and enhances engine thrust. Attached Figure Description

[0007] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 A schematic diagram of the cooling structure assembled in the combustion chamber casing;

[0009] Figure 2 A schematic diagram for setting up the first hole;

[0010] Figure 3This is a schematic diagram of the first cooling channel;

[0011] Figure 4 This is a schematic diagram showing the installation of the third hole, where...

[0012] 1. Combustion chamber casing; 2. Diffuser; 3. Ignition nozzle; 4. Flame tube; 5. Auxiliary fuel inlet pipe; 6. Main fuel inlet pipe; 7. Cooling water inlet connector; 8. Outer ring; 9. Inner ring; 10. Cap cover; 11. Fuel nozzle; 12. Swirl generator; 13. Auxiliary fuel collecting chamber; 14. Main fuel collecting chamber; 15. Water collecting chamber; 17. First fuel delivery path; 18. Cooling water inlet pipe; 19. Second fuel delivery path; 20. Auxiliary fuel passage; 21. Main fuel passage; 24. Second cooling channel; 25. Support pin; 26. Main combustion port; 27. First hole; 28. Second hole; 29. ​​Third hole. Detailed Implementation

[0013] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0014] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0015] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one 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 set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functionalities besides one or more of the aspects set forth herein.

[0016] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0017] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that these aspects can be practiced without these specific details.

[0018] A conventional combustion chamber includes a combustion chamber housing 1, a flame tube 4, a diffuser 2, and an ignition nozzle 3. The flame tube 4 includes an inner ring 9, an outer ring 8, and a fuel nozzle 11. The inner ring 9 and the combustion chamber housing 1 are provided with a support pin 25 at a preset position. The head of the fuel nozzle 11 is provided with a swirler 12. Part of the air diffused by the diffuser 2 is delivered to the two-stream channel of the flame tube 4.

[0019] To improve the engine's thrust-to-weight ratio, increase the combustion chamber temperature rise range, and meet the cooling requirements of the combustor wall temperature while reducing the amount of cooling air, during engine operation, most of the air flowing in from the diffuser enters the combustor head through the cyclone separator to participate in combustion. 5%-10% of the gas enters the inner annular two-stream channel of the combustor, with some participating in the inner annular wall cooling. 5% of the gas enters the outer annular two-stream channel; except for the gas required for the main combustion port in the outer annulus, the remaining gas, along with fuel and cooling water, completes the cooling of the outer annular wall. The fuel flow rate for cooling is consistent with the fuel quantity required for the corresponding engine operating conditions. All the heat-exchanged fuel enters the fuel nozzle and participates in combustion. After heat exchange, all the cooling water enters the combustor through the mixing channel to participate in engine thrust enhancement and optimization. For the composite cooling combustion chamber structure of this invention, see [link to relevant documentation]. Figure 1The combustion chamber casing shown is equipped with a cooling structure suitable for cooling the wall of the flame tube 4 (in the traditional method, the inner and outer rings 8 are both single-layer structures). The flame tube 4 includes an inner ring 9 and an outer ring 8, and the head of the flame tube 4 is equipped with a nozzle for fuel supply. The modified version of this invention uses a double-layer structure for the outer ring 8, forming a cooling structure that can cool the outer ring 8. The cooling structure, such as water passages, oil passages, and orifices, effectively utilizes the engine's own resources for cooling. Through an oil-air-water composite cooling method, only a small amount of cooling air is used, with most air entering the flame tube head, ensuring sufficient combustion distance within the flame tube for complete fuel combustion. Furthermore, the participation of a small amount of cooling air reduces the combustion chamber wall temperature to below the long-term allowable temperature of the material, ensuring the service life of the combustion chamber under high-temperature flames. In addition, after heat exchange, all the cooling water enters the combustion chamber through the mixing channel, contributing to increased engine thrust. Preheating the fuel within a suitable temperature range helps reduce fuel viscosity, improve fuel atomization quality, and enhance combustion chamber performance.

[0020] As a specific implementation method provided in this case, such as Figure 2 As shown, main combustion holes 26 are spaced at predetermined positions around the outer ring 8, and these main combustion holes allow air to enter and participate in combustion. The predetermined positions of the main combustion holes 26 are determined based on the engine model and design parameters. The cooling structure includes a first hole 27 (which serves as a film cooling hole) on the outer ring 8 between adjacent main combustion holes 26. Cooling gas from the two flow channels of the combustion chamber enters the combustion chamber through the first hole 27, effectively cooling the inner wall surface of the outer ring 8 between the main combustion holes 26.

[0021] As a specific implementation method provided in this case, such as Figure 2 As shown, a secondary oil inlet connector and a main oil inlet connector (not marked in the figure) are arranged adjacent to each other at preset positions on the combustion chamber casing 1. (The preset positions are determined based on the convenience of the fuel supply device, and are set in positions that are easy to install or connect). A secondary oil inlet pipe 5 and a main oil inlet pipe 6 are arranged on the outer ring 8 near the first hole 27 and facing the direction of the cooling gas flow. One end of each of the secondary oil inlet pipe 5 and the main oil inlet pipe 6 extends out of the combustion chamber casing 1 and connects with the corresponding secondary oil inlet connector and main oil inlet connector. The assembly of the secondary oil inlet connector and the main oil inlet connector is connected to the fuel supply device. The cooling structure also includes a first cooling channel. A main oil collecting chamber 14 and a secondary oil collecting chamber 13 are respectively arranged circumferentially on the outer ring 8, corresponding to the secondary oil inlet pipe 5 and the main oil inlet pipe 6. Cooling is achieved using their own fuel supply, and the fuel is preheated during the cooling process to improve the combustion efficiency of the fuel.

[0022] The first cooling channel includes first cavities (axially arranged) spaced apart on the outer ring 8 in the direction of the incoming flow of cooling gas, such as... Figure 3As shown, each first cavity is divided into two independent first oil delivery paths 17 and second oil delivery paths 19. The first oil delivery path 17 is connected to the main oil collecting chamber 14, and the second oil delivery path 19 is connected to the auxiliary oil collecting chamber 13. This allows the first oil delivery path 17 to connect to the main oil passage 21 of the nozzle at the head of the flame tube 4, and the second oil delivery path 19 to connect to the auxiliary oil passage 20 of the nozzle at the head of the flame tube 4. The oil input from the auxiliary oil inlet connector and the main oil inlet connector enters the first oil delivery path 17 and the second oil delivery path 19 through the auxiliary oil inlet pipe 5 and the main oil inlet pipe 6, respectively. This preheating process allows the low-temperature oil to be cooled on the inner wall surface of the outer ring 8. It should be noted that effectively utilizing the heat within the flame tube 4 space to preheat the oil can improve the efficiency of fuel atomization at the nozzle.

[0023] As a specific implementation provided in this case, in combination with some or all of the above-mentioned solutions, the cooling structure also includes a second hole 28. The second hole 28 is disposed circumferentially on the outer ring 8 and between two adjacent first cavities. The cooling gas of the two flow channels of the combustion chamber enters the combustion chamber through the second hole 28, which can cool the inner wall surface of the outer ring 8.

[0024] The cooling structure also includes a second cooling channel 24. A cooling water inlet pipe 18 is installed on the outer ring 8 near the combustion chamber outlet, and a cooling water inlet connector 7 is installed at the corresponding position on the combustion chamber casing 1. The cooling water inlet connector 7 is connected to an external water supply device. The cooling water provided by the external water supply device is the engine's secondary water, specifically, as follows: Figure 4 As shown,

[0025] A water collecting chamber 15 (a hollow annular structure circumferentially around the outer ring 8) is provided circumferentially around the outer ring 8 and corresponding to the cooling water inlet pipe 18. A second cooling channel 24 is provided between the main combustion port 26 and the water collecting chamber 15, and the water collecting chamber 15 is connected to the second cooling channel 24. A third hole 29 is provided at intervals on the second cooling channel 24. The cooling water inlet connector 7 provides cooling water to flow into the cooling water inlet pipe 18 and enter the combustion chamber through the third hole 29, which can cool the inner wall surface of the outer ring 8 and regulate the temperature field at the combustion chamber outlet. The purpose of the third hole 29 is to control the water pressure in the second cooling channel 24, thereby achieving cooling of the inner wall surface of the outer ring of the flame tube and regulating the temperature field at the combustion chamber outlet, providing a simple temperature control method, and at the same time, improving the engine thrust to a certain extent.

[0026] The combined use of the above-mentioned cooling structures yields optimal results. When the aero-engine is operating, most of the air flowing in from the diffuser 2 enters the head of the flame tube 4 through the vortex generator 12 to participate in combustion. 5%-10% of the gas enters the two-stream channel of the inner ring 9 of the flame tube 4 to participate in the cooling of the inner ring 9 wall. The remaining gas enters the two-stream channel of the outer ring 8. Besides meeting the air supply requirements of the main combustion port 26, only a small amount of cooling gas passes through the straight holes and film cooling holes to cool the area in front of the main combustion port 26. The remaining area in front of the main combustion port 26 is cooled by fuel heat exchange. The heat-exchanged fuel enters the flame tube 4 through the fuel nozzle 11 to participate in combustion. The area behind the main combustion port 26 is cooled by cooling water. The heat-exchanged cooling water enters the flame tube 4 through the mixing channel to participate in film cooling, outlet temperature field regulation, and engine thrust enhancement optimization. The aforementioned combustion chamber composite cooling scheme effectively utilizes cooling water, fuel, and air, and eliminates the problem of cooling medium recovery. The fuel and cooling water control methods are simple, which can effectively reduce the temperature of the flame tube wall, ensure combustion performance and engine operation stability, and provide a solution to further broaden the combustion chamber temperature rise boundary.

[0027] Furthermore, the device includes a cap 10, the two ends of which are connected to the outer ring 8 and the inner ring 9 respectively by bolts. The cap can guide the compressor to flow into the head of the flame tube and the two flow channels of the inner and outer rings with a small pressure loss.

[0028] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A composite cooling combustion chamber structure, suitable for cooling the wall of a flame tube, the flame tube comprising an inner ring and an outer ring, and an oil supply passage with a nozzle at the head of the flame tube, characterized in that, The outer ring is configured with a double-layer structure and has a cooling structure that can cool the outer ring. The outer ring is provided with main combustion holes at predetermined positions around its circumference. The cooling structure includes a first hole on the outer ring and between adjacent main combustion holes. Cooling gas from the two flow channels of the combustion chamber enters the combustion chamber through the first hole to cool the inner wall surface of the outer ring between the main combustion holes. A secondary oil inlet connector and a main oil inlet connector are arranged adjacent to each other at predetermined positions on the combustion chamber casing. A secondary oil inlet pipe and a main oil inlet pipe are arranged on the outer ring near the first hole and facing the direction of the cooling gas flow. The cooling structure also includes a first cooling channel. A main oil collecting chamber and a secondary oil collecting chamber are respectively arranged circumferentially on the outer ring, corresponding to the secondary oil inlet pipe and the main oil inlet pipe. The first cooling channel includes first cavities spaced apart on the outer ring facing the direction of the cooling gas flow. Each first cavity is divided into two... There are two independent oil delivery paths: a first oil delivery path and a second oil delivery path. The first oil delivery path is connected to the main oil collection chamber, and the second oil delivery path is connected to the auxiliary oil collection chamber. The first oil delivery path is connected to the main oil path of the flame tube head nozzle, and the second oil delivery path is connected to the auxiliary oil path of the flame tube head nozzle. When the oil input from the auxiliary oil inlet connector and the main oil inlet connector enters the first oil delivery path and the second oil delivery path through the auxiliary oil inlet pipe and the main oil inlet pipe, respectively, it can be preheated, and the inner wall surface of the outer ring is cooled during the preheating process. The cooling structure also includes a second cooling channel. A cooling water inlet pipe is provided on the outer ring near the combustion chamber outlet end, and a cooling water inlet connector is provided at the corresponding position of the combustion chamber casing. The cooling water inlet connector is connected to an external water supply device, and the cooling water provided by the external water supply device is the engine's secondary water. A water collection chamber is provided circumferentially on the outer ring and at a position corresponding to the cooling water inlet pipe. A second cooling channel is provided at intervals between the main combustion port and the water collection chamber. The water collection chamber is connected to the second cooling channel, and a third hole is provided at intervals on the second cooling channel. The cooling water inlet connector provides cooling water to flow into the cooling water inlet pipe and enter the combustion chamber through the third hole. This can cool the inner wall surface of the outer ring, regulate the temperature field at the combustion chamber outlet, and increase the engine thrust.

2. The composite cooling combustion chamber structure according to claim 1, characterized in that, The cooling structure also includes a second hole, which is disposed circumferentially on the outer ring and between two adjacent first cavities. Cooling gas from the two flow channels of the combustion chamber enters the combustion chamber through the second hole, thereby cooling the inner wall of the outer ring.

3. The composite cooling combustion chamber structure according to claim 1, characterized in that, It also includes a cap, the two ends of which are connected to the outer ring and the inner ring respectively by bolts.

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