Double-walled fuel line

Abstract

The application discloses a double-wall fuel manifold, which comprises a fuel main pipe, a fuel inlet nozzle communicated with the fuel main pipe, a plurality of fuel branch pipes, a heat insulation sleeve main pipe, an air inlet connector communicated with the heat insulation sleeve main pipe and a plurality of heat insulation sleeve branch pipes. The plurality of fuel branch pipes are sequentially arranged and each fuel branch pipe is communicated with the fuel main pipe. The heat insulation sleeve main pipe is sealed and sleeved outside the fuel main pipe. The plurality of heat insulation sleeve branch pipes are sleeved outside the plurality of fuel branch pipes, and each heat insulation sleeve branch pipe is communicated with the heat insulation sleeve main pipe, so that heat exchange air enters a first branch heat exchange flow channel between each heat insulation sleeve branch pipe and the fuel branch pipe, and small holes are formed in the outer wall of each heat insulation sleeve branch pipe to allow the heat exchange air to be discharged from the fuel manifold. The fuel manifold can effectively solve the problems of fuel coking and freezing of the fuel manifold of an aero-engine in an extreme environment, ensure fuel flow rate and flow, prevent performance attenuation of engine flameout in the extreme environment and widen the working field of the engine.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine fuel manifold technology, and in particular, to a double-walled fuel manifold. Background Technology

[0002] With the development of aero-engine design and manufacturing technologies, aero-engines are evolving towards higher thrust-to-weight ratios and wider operating ranges. The combustion chamber is one of the three core components of an aero-engine. In the thermodynamic cycle of a gas turbine engine, the combustion chamber completes the heating process, converting the chemical energy of combustion into heat energy to drive the turbine, making it the "heart" of the engine. The fuel manifold, as a crucial component of the engine's fuel supply system, primarily functions to evenly deliver fuel to the combustion chamber, providing power, making it the "blood vessels" of the engine. In conventional fuel manifold designs, based on different materials and structural forms, they can be divided into flexible hoses and rigid hoses. Flexible fuel hoses are mostly made of polytetrafluoroethylene (PTFE), which is resistant to acids, alkalis, and various organic solvents. However, their relatively large outer diameter makes them prone to excessive twisting when installed in engines with smaller combustion chamber diameters, affecting safety. Rigid fuel hoses are lightweight, primarily made of stainless steel or high-temperature alloys. Material procurement is simple, and processing is less difficult, making them suitable for higher-power engines.

[0003] Existing fuel manifold technologies are mostly single-walled structures. In low-temperature environments such as high altitudes and plateaus, the fuel flow rate in the manifold is low, making it prone to icing and freezing. This severely affects the fuel flow rate within the fuel manifold, prolongs the filling time, and reduces the combustion chamber ignition performance, thus impacting the overall engine ignition performance in high-altitude and plateau environments. In high-temperature environments, existing fuel manifolds are prone to fuel coking within the metal manifold, reducing the flow area. Under the same fuel supply pressure, this results in a lower fuel flow rate, affecting the combustion chamber ignition performance. Furthermore, when a single-walled fuel manifold experiences a leak due to poor sealing, pipe cracks, or breakage while the engine is running, it can easily lead to engine fires and other safety accidents.

[0004] The state of fuel in the fuel manifold under extreme environments (high temperature, high cold environment) has a significant impact on the ignition and shutdown performance of the engine combustion chamber. Effectively ensuring the state of fuel in the fuel manifold can greatly broaden the engine's operating range and improve engine performance. Summary of the Invention

[0005] This invention provides a double-walled fuel manifold to solve the technical problems of existing fuel manifolds, such as fuel coking and freezing in extreme environments of aero engines, and the risk of engine fires and other safety accidents caused by large-scale fuel leakage due to poor sealing, pipe cracks, or breakage during engine operation.

[0006] The technical solution adopted in this invention is as follows:

[0007] A double-walled fuel main pipe includes: a fuel main pipe, a fuel inlet nozzle connected to the fuel main pipe, multiple fuel branch pipes, a heat-insulating main pipe, an air inlet nozzle connected to the heat-insulating main pipe, and multiple heat-insulating branch pipes corresponding to the multiple fuel branch pipes; the multiple fuel branch pipes are arranged sequentially along the extension direction of the fuel main pipe, and the fuel inlet end of each fuel branch pipe is connected to the fuel main pipe; the heat-insulating main pipe is sealed and fitted outside the fuel main pipe, so that heat-exchange air entering from the air inlet nozzle enters the main heat exchange channel between the heat-insulating main pipe and the fuel main pipe; the multiple heat-insulating branch pipes are fitted one by one outside the multiple fuel branch pipes, and the first end of each heat-insulating branch pipe is connected to the heat-insulating main pipe, so that heat-exchange air in the main heat exchange channel enters the first heat exchange channel between each heat-insulating branch pipe and the corresponding fuel branch pipe, and each heat-insulating branch pipe is also provided with a small hole in its outer wall communicating with the outside, so that heat-exchange air in the first heat exchange channel can be discharged out of the fuel main pipe.

[0008] Furthermore, the fuel branch pipe and the fuel main pipe are separately configured. The fuel main pipe has a branch pipe flow channel hole that penetrates the wall corresponding to the fuel branch pipe. The double-walled fuel main pipe also includes a first connecting pipe assembly for detachably connecting the fuel branch pipe and the fuel main pipe. The first connecting pipe assembly includes: a branch pipe straight connector fixed to the outer circle of the fuel main pipe and communicating with the branch pipe flow channel hole; a branch pipe nozzle fixedly communicating with the branch pipe straight connector; and a first outer nut that limits and fits on the outer circle of the fuel inlet end of the fuel branch pipe. The fuel inlet end of the fuel branch pipe is flared to cover the branch pipe nozzle. The first outer nut is threaded to the outer circle of the branch pipe nozzle to seal the fuel inlet end of the fuel branch pipe tightly around the branch pipe nozzle during tightening.

[0009] Furthermore, the heat insulation sleeve branch pipe and the heat insulation sleeve main pipe are separately configured. The double-walled fuel main pipe also includes a second outer nut for detachably connecting the two, and a sealing gasket for sealing. The first end of the heat insulation sleeve branch pipe is located inside the second outer nut and is pressed against the second outer nut by the sealing gasket. The second end of the heat insulation sleeve branch pipe is fixed to the fuel branch pipe. The second outer nut is threadedly connected to the branch pipe connector extending outward on the heat insulation sleeve main pipe, so as to pull the first end of the heat insulation sleeve branch pipe and the branch pipe connector relatively tight during the tightening process.

[0010] Furthermore, the heat insulation sleeve branch pipe includes a coaxial inner branch pipe and an outer branch pipe that are fitted together, and a sealing end plate for sealing the annular gap at the first end of both; a second heat exchange channel for heat exchange airflow is formed between the inner branch pipe and the outer branch pipe, and a small hole is opened on the wall surface of the first end of the outer branch pipe; the inner wall surface of the second outer sleeve nut protrudes towards the center to form a limiting flange, and a sealing gasket is located between the sealing end plate and the limiting flange; the second end of the outer branch pipe is sealed and welded to the oil outlet end of the fuel branch pipe, and a small hole for connecting the tail end of the second branch pipe to the second heat exchange channel is opened on the end face of the second end of the inner branch pipe.

[0011] Furthermore, the fuel main pipe is ring-shaped, including multiple fuel pipe segments arranged sequentially along the circumference, and a second connecting pipe assembly for detachably connecting two adjacent fuel pipe segments is provided between them; multiple fuel branch pipes are evenly spaced along the circumference of the fuel main pipe.

[0012] Furthermore, the second connecting pipe assembly includes a main pipe sleeve and a main pipe straight connector respectively fixed to the two adjacent fuel pipe ends, and a third outer nut; one end of the third outer nut is limited and installed on the outer circle of the main pipe sleeve, and the other end is used to be threadedly connected to the main pipe straight connector so as to pull the two fuel pipe ends relatively tight during tightening.

[0013] Furthermore, the heat insulation main pipe is formed by welding the left half heat insulation sleeve and the right half heat insulation sleeve which are split in half, and the right half heat insulation sleeve has an extended branch pipe connector; the heat insulation main pipe also includes multiple heat insulation sleeves that correspond one-to-one with multiple fuel pipes along the circumference, and a third connector assembly for detachably connecting two adjacent heat insulation sleeves is provided between them.

[0014] Furthermore, the third connecting pipe assembly includes a sealing ring composed of two sealing sleeve halves arranged axially, a clamp washer for sealing the gap between the two sealing sleeve halves, and a sealing clamp for tightening the clamp washer and the sealing ring; the sealing ring is fitted onto the outer circle of the two adjacent insulation sleeve ends; the clamp washer is fitted onto the outer circle of the sealing ring; and the sealing clamp is detachably tightened onto the outer circle of the clamp washer.

[0015] Furthermore, each end of the inner ring cavity of the sealing sleeve half ring is provided with a concave and semi-circular semi-ring fixing groove, and the outer circle of the sealing sleeve half ring is also provided with a sealing ring groove that is axially spaced and concave and semi-circular; the two semi-ring fixing grooves are used to respectively hold the outwardly protruding connecting rings on the outer circle of the two heat insulation sleeve ends; the sealing ring groove is used to cooperate with the clamp washer to seal the gap between the two sealing sleeve half rings.

[0016] Furthermore, the clamp washer is a "C" shape with a notch, and its inner ring surface is provided with a sealing convex ring that mates with the sealing ring groove. The end face of the notch is also provided with a clamp fixing groove that extends inward to penetrate the two end faces of the clamp washer. The sealing clamp passes through the clamp fixing groove circumferentially, and its two ends extend out from the notch of the clamp washer and are connected to the clamp locking pin.

[0017] The present invention has the following beneficial effects:

[0018] The present invention provides a double-walled fuel manifold that, by introducing temperature-adjustable air outside the fuel flow channel of the fuel manifold, enhances convective heat transfer between the main fuel pipe and fuel branch pipes, thus providing thermal insulation protection for the fuel manifold. In high-temperature environments (high altitude, frigid regions), the high ambient temperature outside the fuel manifold allows for the introduction of low-temperature air to protect the fuel flow channel and prevent fuel coking. Conversely, in low-temperature environments (high altitude, frigid regions), the low ambient temperature outside the fuel manifold allows for the introduction of high-temperature air to protect the fuel flow channel, preventing increased fuel viscosity or even freezing under low-temperature conditions. This effectively solves the problems of fuel coking and freezing in the fuel manifold of aero-engines in extreme environments, ensuring fuel flow rate and volume, preventing engine ignition performance degradation under extreme conditions, and expanding the engine's operating range. The double-walled fuel manifold of this invention provides double-layer protection, effectively solving the problem of excessive fuel spillage due to poor sealing, pipe cracks, or breaks in the fuel flow channel, preventing engine fires during operation, and ensuring engine safety.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a front view schematic diagram of the double-walled fuel main pipe according to a preferred embodiment of the present invention;

[0022] Figure 2 yes Figure 1 A schematic diagram of the left-side view structure;

[0023] Figure 3 yes Figure 1 Schematic diagram of the cross-sectional structure along the middle AA direction;

[0024] Figure 4 yes Figure 1 Schematic diagram of the working principle of the double-walled fuel main;

[0025] Figure 5 yes Figure 2 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0026] Figure 6 yes Figure 5 A magnified schematic diagram of the structure at point I in the middle;

[0027] Figure 7 yes Figure 3 Schematic diagram of the cross-sectional structure of the branch pipe of the heat insulation sleeve;

[0028] Figure 8 yes Figure 3 Schematic diagram of the main structure of the clamp washer;

[0029] Figure 9 yes Figure 8 Schematic diagram of the cross-sectional structure along the CC direction;

[0030] Figure 10 yes Figure 3 Schematic diagram of the spatial structure of the central sealing clamp;

[0031] Figure 11 yes Figure 3 A schematic diagram of the main structure of the central sealing sleeve semi-ring.

[0032] Legend:

[0033] 1. Fuel inlet nozzle; 2. Air inlet nozzle; 3. Left half heat insulation sleeve; 4. Right half heat insulation sleeve; 5. Second outer sleeve nut; 6. Heat insulation sleeve branch pipe; 603. Tail end small hole; 604. Outer wall small hole; 605. Branch pipe outer tube; 606. Branch pipe inner tube; 607. Sealing end plate; 7. Nozzle connection outer sleeve nut; 8. Clamp washer; 801. Clamp fixing groove; 803. Sealing convex ring; 9. Sealing clamp; 10. Branch pipe straight... 11. Fuel main pipe; 1101. Main heat exchange channel; 1102. Branch pipe channel hole; 12. Branch pipe connector; 13. First outer sleeve nut; 14. Fuel branch pipe; 15. Sealing gasket; 16. Main pipe sleeve; 17. Third outer sleeve nut; 18. Main pipe straight connector; 19. Sealing sleeve half ring; 1901. Half ring fixing groove; 1902. Inner ring cavity; 1903. Sealing ring groove; 20. Nozzle connection. Detailed Implementation

[0034] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0035] Reference Figure 1-3A preferred embodiment of the present invention provides a double-walled fuel main pipe, comprising: a fuel main pipe 11, a fuel inlet nozzle 1 connected to the fuel main pipe 11, multiple fuel branch pipes 14, a heat-insulating main pipe, an air inlet nozzle 2 connected to the heat-insulating main pipe, and multiple heat-insulating branch pipes 6 corresponding to the multiple fuel branch pipes 14. The multiple fuel branch pipes 14 are arranged sequentially along the extension direction of the fuel main pipe 11, and the fuel inlet end of each fuel branch pipe 14 is connected to the fuel main pipe 11. The heat-insulating main pipe is sealed and fitted over the fuel main pipe 11 so that heat exchange air entering from the air inlet nozzle 2 can enter the main heat exchange channel 1101 between the heat-insulating main pipe and the fuel main pipe 11. Multiple heat-insulating branch pipes 6 are fitted onto multiple fuel branch pipes 14, and the first end of each heat-insulating branch pipe 6 is connected to the heat-insulating main pipe, so that the heat exchange air in the main heat exchange channel 1101 can enter the first heat exchange channel between each heat-insulating branch pipe 6 and the corresponding fuel branch pipe 14. Each heat-insulating branch pipe 6 is also provided with a small hole 604 on the outer wall that communicates with the outside, so that the heat exchange air in the first heat exchange channel can be discharged out of the fuel main pipe.

[0036] The specific working process of the double-walled fuel manifold of this invention is as follows: When the engine is at high altitude or in high-altitude areas, the low ambient temperature can easily cause slow fuel flow or even freezing in the fuel manifold, severely affecting the engine's ignition and shutdown performance. In low-temperature conditions, upon engine ignition, fuel is supplied by the fuel pump and enters the double-walled fuel manifold through the fuel distributor and fuel inlet 1. The fuel is dispersed through the main fuel pipe 11 and enters the fuel branch pipe 14, then reaches the nozzle connector 20 at the outlet of the fuel branch pipe 14, completing the fuel supply to the fuel nozzles. Simultaneously, the engine air supply device is activated, supplying high-temperature air with controllable temperature through the air intake connector 2. This air heats the main fuel pipe 11 through the main heat exchange channel 1101 within the heat-insulating jacket, using convective heat transfer to ensure the fuel in the main pipe maintains a high temperature and a consistent flow rate. The high-temperature air from the main fuel line then enters the first heat exchange channel between each heat-insulating branch pipe 6 and the corresponding fuel branch pipe 14, heating the fuel branch pipe 14. This convective heat exchange forms a protective layer, and the air is discharged outwards through the small holes 604 on the outer wall of the main fuel line, thus preventing freezing and ensuring the fuel flow rate in the fuel branch pipe 14. This improves the engine's fuel supply response in high-altitude and high-altitude areas, thereby enhancing the engine's ignition and shutdown performance in such environments. Following the same principle, in extreme tropical regions where the engine operates at high temperatures, the high fuel temperature in the main fuel line can easily cause coking inside the line and at the fuel nozzles. To avoid this, low-temperature air is supplied simultaneously during ignition, creating convective heat exchange between the main fuel line 11 and the fuel branch pipes 14. This lowers the fuel temperature, effectively preventing coking inside the line and at the fuel nozzles, thus ensuring the flow area of ​​the fuel channel and guaranteeing the engine's fuel supply flow rate in high-temperature environments, further improving the engine's ignition and shutdown performance.

[0037] The present invention provides a double-walled fuel manifold that, by introducing temperature-adjustable air outside the fuel flow channel of the fuel manifold, enhances convective heat transfer between the main fuel pipe 11 and the branch fuel pipe 14, thus providing thermal insulation protection for the fuel manifold. In high-temperature environments (high altitude, frigid regions), the high ambient temperature outside the fuel manifold allows for the introduction of low-temperature air to protect the fuel flow channel and prevent fuel coking. Conversely, in low-temperature environments (high altitude, frigid regions), the low ambient temperature outside the fuel manifold allows for the introduction of high-temperature air to protect the fuel flow channel, preventing increased fuel viscosity or even freezing under low-temperature conditions. This effectively solves the problems of fuel coking and freezing in the fuel manifold of aero-engines in extreme environments, ensuring fuel flow rate and volume, preventing engine ignition performance degradation under extreme conditions, and expanding the engine's operating range. The double-walled fuel manifold of the present invention provides double-layer protection, effectively solving the problem of excessive fuel spillage due to poor sealing, pipe cracks, or breaks in the fuel flow channel, preventing engine fires during operation, and ensuring engine safety.

[0038] Optionally, such as Figure 3 and Figure 5 As shown, the fuel branch pipe 14 and the fuel main pipe 11 are separately configured. A branch pipe flow channel hole 1102, penetrating the wall of the fuel main pipe 11, is provided corresponding to the location of the fuel branch pipe 14. The double-walled fuel main pipe also includes a first connecting pipe assembly for detachably connecting the fuel branch pipe 14 and the fuel main pipe 11. The first connecting pipe assembly includes: a branch pipe straight connector 10 fixed to the outer circumference of the fuel main pipe 11 and communicating with the branch pipe flow channel hole 1102; a branch pipe nozzle 12 fixedly communicating with the branch pipe straight connector 10; and a first outer sleeve nut 13, which is limited and fitted onto the outer circumference of the fuel inlet end of the fuel branch pipe 14. The fuel inlet end of the fuel branch pipe 14 is flared to fit over the branch pipe nozzle 12. The first outer nut 13 is threadedly connected to the outer surface of the branch pipe connector 12, so that the fuel inlet end of the fuel branch pipe 14 is sealed tightly around the branch pipe connector 12 during tightening, thereby achieving a sealed connection between the branch pipe connector 12 and the fuel branch pipe 14. This achieves a detachable sealed connection between the fuel branch pipe 14 and the fuel main pipe 11, effectively improving the replaceability, assemblability, and maintainability of the fuel main pipe, reducing maintenance costs, and possessing high engineering application value. During operation, external fuel enters the fuel branch pipe 14 sequentially through the fuel inlet 1, fuel main pipe 11, branch pipe straight connector 10, and branch pipe connector 12, and finally enters the fuel nozzle through the nozzle connecting outer nut 7 located outside the nozzle connecting nozzle 20, and is atomized and sprayed outward through the fuel nozzle.

[0039] Optionally, such as Figure 3As shown, the heat insulation sleeve branch pipe 6 and the heat insulation sleeve main pipe are separately configured. The double-walled fuel main pipe also includes a second outer nut 5 for detachable connection of the two, and a sealing gasket 15 for sealing. The first end of the heat insulation sleeve branch pipe 6 is located inside the second outer nut 5 and is abutted against the second outer nut 5 by the sealing gasket 15. The second end of the heat insulation sleeve branch pipe 6 is fixed to the fuel branch pipe 14. The second outer nut 5 is threadedly connected to the branch pipe connector extending outward on the heat insulation sleeve main pipe, so that the first end of the heat insulation sleeve branch pipe 6 and the branch pipe connector are pulled together during tightening. During operation, external regulating air first enters the main heat exchange channel 1101 between the heat insulation sleeve main pipe and the fuel main pipe 11 through the air inlet 2, then enters the gap between the branch pipe connector and the second outer nut 5 and the first connector assembly, then enters the first branch heat exchange channel between the heat insulation sleeve branch pipe 6 and the fuel branch pipe 14, and finally exits the fuel main pipe through the small hole 604 on the outer wall. In this optional solution, the heat insulation sleeve branch pipe 6 and the heat insulation sleeve main pipe are set separately, and the gap between the heat insulation sleeve branch pipe 6 and the second outer sleeve nut 5 is realized by the sealing gasket 15, thereby realizing the detachable and sealed connection between the heat insulation sleeve branch pipe 6 and the heat insulation sleeve main pipe, effectively improving the replaceability, assemblability and maintainability of the fuel main pipe, reducing maintenance costs, and having high engineering application value.

[0040] In this optional solution, such as Figure 3 and Figure 7 As shown, the heat-insulating branch pipe 6 includes a coaxial inner branch pipe 606 and an outer branch pipe 605, which are fitted together, and a sealing end plate 607 for sealing the annular gap at the first end of both. A second heat exchange channel for heat exchange airflow is formed between the inner branch pipe 606 and the outer branch pipe 605, and a small hole 604 is opened on the wall surface of the first end of the outer branch pipe 605. The inner wall surface of the second outer sleeve nut 5 protrudes towards the center to form a limiting flange, and the sealing gasket 15 is located between the sealing end plate 607 and the limiting flange. The second end of the outer branch pipe 605 is sealed and welded to the oil outlet end of the fuel branch pipe 14, and a small end hole 603 communicating with the second heat exchange channel is opened on the end face of the second end of the inner branch pipe 606. During operation, as Figure 4 As shown, the heat exchange air passes through the branch pipe inlet 12 and the fuel branch pipe 14, and then reaches the inlet area of ​​the heat insulation sleeve branch pipe 6. It flows in reverse through the small hole 603 at the end into the second heat exchange channel between the outer branch pipe 605 and the inner branch pipe 606. Finally, it flows out from the small hole 604 on the outer wall of the first end of the outer branch pipe 605, forming multiple convective heat exchange for the fuel branch pipe 14. This forms protection and prevents freezing and coking, ensuring the fuel flow rate of the fuel branch pipe 14. It also improves the engine fuel supply response in high-altitude, high-altitude, and high-heat areas, thereby improving the engine's ignition and shutdown performance in high-altitude, high-altitude, or high-heat environments.

[0041] In a specific embodiment of this optional scheme, the number of heat insulation sleeve branch pipes 6 is designed to match the fuel branch pipes 14, and the selection range can be considered to be 8 to 24. The heat insulation sleeve branch pipe 6 has a double-wall structure, the diameter of the small holes 603 at the tail end ranges from 0.5 to 1.5 mm, and the number is 10 to 30; the diameter of the small holes 604 on the outer wall ranges from 0.5 to 2.0 mm, and the number is 10 to 40.

[0042] Optionally, such as Figure 5 As shown, the main fuel line 11 is annular, comprising multiple fuel pipe segments arranged sequentially along the circumference, with a second connecting pipe assembly between adjacent fuel pipe segments for detachable connection. Multiple fuel branch pipes 14 are evenly spaced along the circumference of the main fuel line 11. In this optional configuration, the main fuel line 11 is segmented and detachable connections are achieved through the second connecting pipe assembly, thereby increasing the replaceability and maintainability of the main fuel line and possessing high engineering application value.

[0043] In this optional solution, such as Figure 6 As shown, the second connector assembly includes a main pipe sleeve 16 and a main pipe straight connector 18, respectively fixed to the two adjacent fuel pipe ends, and a third outer nut 17. One end of the third outer nut 17 is positioned on the outer circumference of the main pipe sleeve, and the other end is threaded to the main pipe straight connector 18 to pull the two fuel pipe ends together during tightening. In this optional embodiment, such as... Figure 6 As shown, the outer circle of the main tube sleeve 16 has a limiting cone surface, and the inner circumference of the third outer nut 17 is provided with a cone surface that mates with the limiting cone surface. The third outer nut 17 is axially limited by the mating of its inner cone surface with the limiting cone surface, thereby preventing the third outer nut 17 from coming off the main tube sleeve 16.

[0044] Optionally, such as Figure 5 As shown, the main heat insulation sleeve is formed by welding a left half heat insulation sleeve 3 and a right half heat insulation sleeve 4, which are split in half, together. The right half heat insulation sleeve 4 has an extended branch pipe. The main heat insulation sleeve also includes multiple heat insulation sleeves that correspond to multiple fuel pipe sections circumferentially, and a third connecting pipe assembly for detachably connecting two adjacent heat insulation sleeve sections is provided. In this optional scheme, the main heat insulation sleeve can be processed by various methods such as additive manufacturing and casting. The diameter of the main pipe is determined based on the outer diameter of the fuel main pipe 11, the air flow area, etc., and the selection range is 10-30mm. The main heat insulation sleeve adopts a half-pipe structure design and circumferential segmentation, and achieves detachable connection through the third connecting pipe assembly, thereby increasing the replaceability and maintainability of the fuel main pipe and having high engineering application value.

[0045] In this optional solution, such as Figure 6As shown, the third connector assembly includes a sealing ring composed of two axially split sealing half-rings 19, a clamping washer 8 for sealing the gap between the two sealing half-rings 19, and a sealing clamp 9 for tightening the clamping washer 8 and the sealing ring. The sealing ring is fitted onto the outer circumference of the two adjacent insulation sleeve ends. The clamping washer 8 is fitted onto the outer circumference of the sealing ring. The sealing clamp 9 is detachably tightened onto the outer circumference of the clamping washer 8.

[0046] In specific embodiments of this optional solution, such as Figure 11 As shown, the inner annular cavity 1902 of the sealing sleeve half-ring 19 has a concave, semi-annular semi-ring fixing groove 1901 on each end of its wall surface. The outer circumference of the sealing sleeve half-ring 19 also has axially spaced, concave, semi-annular sealing ring grooves 1903. The two semi-annular fixing grooves 1901 are used to respectively hold the convex connecting rings on the outer circumference of the two heat insulation sleeve ends. The sealing ring grooves 1903 are used to cooperate with the clamp washer 8 to seal the gap between the two sealing sleeve half-rings 19. Further, the sealing sleeve half-ring 19 connects the ends of two adjacent heat insulation sleeves and prevents air and fuel leakage. Its two ends are designed with semi-annular fixing grooves 1901 for fixing the heat insulation sleeve. Multiple sealing ring grooves 1903 are designed on its outer wall surface for connecting with the clamp washer 8. The sealing ring grooves 1903 have a width of 2–5 mm, a depth of 1.0–2.5 mm, and a number of 3–6, determined according to the connection length.

[0047] In specific embodiments of this optional solution, such as Figure 8-10 As shown, the clamp washer 8 is a notched "C" shape. Its inner ring surface has a sealing convex ring 803 that mates with the sealing ring groove 1903. The notched end face also has a recessed clamp fixing groove 801 that extends through both end faces of the clamp washer 8. The sealing clamp 9 passes circumferentially into the clamp fixing groove 801, and both ends extend from the notch of the clamp washer 8 and connect to the clamp locking pins. Further, as... Figure 8-9 As shown, the clamp washer 8 is tightly fitted to the sealing sleeve half-ring 19 and tightened by the sealing clamp 9 to achieve a sealing effect; as Figure 10 As shown, the sealing clamp 9 is a thin-walled elastic element used to press the sealing sleeve half ring 19; the wall thickness of the sealing clamp 9 is designed to be 0.5 to 2.0 mm, and the connection and installation holes opened at both ends for the clamp locking pins to pass through are 6 to 14 mm.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A double-walled fuel manifold, characterized in that, include: Fuel main pipe (11), fuel inlet (1) connected to fuel main pipe (11), multiple fuel branch pipes (14), heat insulation main pipe, air inlet (2) connected to heat insulation main pipe, and multiple heat insulation branch pipes (6) corresponding to multiple fuel branch pipes (14). Multiple fuel branch pipes (14) are arranged sequentially along the extension direction of the fuel main pipe (11), and the inlet end of each fuel branch pipe (14) is connected to the fuel main pipe (11). The heat insulation sleeve is sealed outside the fuel pipe (11) so that the heat exchange air entering from the air inlet (2) can enter the main heat exchange channel (1101) between the heat insulation sleeve and the fuel pipe (11). Multiple heat-insulating branch pipes (6) are fitted onto multiple fuel branch pipes (14), and the first end of each heat-insulating branch pipe (6) is connected to the heat-insulating main pipe so that the heat exchange air in the main heat exchange channel (1101) can enter the first heat exchange channel between each heat-insulating branch pipe (6) and the corresponding fuel branch pipe (14). Each heat-insulating branch pipe (6) is also provided with an outer wall hole (604) that communicates with the outside so that the heat exchange air in the first heat exchange channel can be discharged out of the fuel main pipe.

2. The double-walled fuel main according to claim 1, characterized in that, The fuel branch pipe (14) and the fuel main pipe (11) are separately configured. A branch pipe flow channel hole (1102) is provided on the wall of the fuel main pipe (11) corresponding to the fuel branch pipe (14). The double-walled fuel main pipe also includes a first connecting pipe assembly for detachably connecting the fuel branch pipe (14) and the fuel main pipe (11). The first connecting pipe assembly includes: A branch pipe straight connector (10) fixed on the outer circle of the fuel main pipe (11) and connected to the branch pipe flow channel hole (1102), a branch pipe nozzle (12) fixedly connected to the branch pipe straight connector (10), and a first outer sleeve nut (13) limited and fitted on the outer circle of the fuel branch pipe (14) inlet end. The fuel inlet end of the fuel branch pipe (14) is flared to be fitted onto the branch pipe connector (12); The first outer nut (13) is threaded to the outer surface of the branch pipe connector (12) so that the oil inlet end of the fuel branch pipe (14) is sealed and tightly wrapped around the branch pipe connector (12) during the tightening process.

3. The double-walled fuel manifold according to claim 1, characterized in that, The heat insulation sleeve branch pipe (6) and the heat insulation sleeve main pipe are set separately. The double-walled fuel main pipe also includes a second outer nut (5) for detachably connecting the two, and a sealing gasket (15) for sealing. The first end of the heat insulation sleeve branch pipe (6) is located inside the second outer nut (5) and is pressed against the second outer nut (5) by the sealing gasket (15). The second end of the heat insulation sleeve branch pipe (6) is fixed to the fuel branch pipe (14). The second outer nut (5) is threaded to the branch pipe connector extending outward on the main pipe of the insulation sleeve, so as to pull the first end of the branch pipe (6) of the insulation sleeve relative to the branch pipe connector during the tightening process.

4. The double-walled fuel manifold according to claim 3, characterized in that, The heat insulation sleeve branch pipe (6) includes a branch pipe inner pipe (606) and a branch pipe outer pipe (605) that are coaxial and fitted together, and a sealing end plate (607) for sealing the first end annular gap of the two. A second heat exchange channel for heat exchange air flow is formed between the inner tube (606) and the outer tube (605) of the branch pipe, and a small hole (604) is opened on the wall surface of the first end of the outer tube (605); The inner wall of the second outer nut (5) protrudes towards the center to form a limiting flange, and the sealing gasket (15) is located between the sealing end plate (607) and the limiting flange; The second end of the outer pipe (605) of the branch pipe is sealed and welded to the oil outlet end of the fuel branch pipe (14), and a small hole (603) connecting the tail end of the second heat exchange channel is opened on the end face of the inner pipe (606) of the branch pipe.

5. The double-walled fuel main according to claim 1, characterized in that, The fuel main pipe (11) is annular and includes multiple fuel pipes arranged sequentially along the circumference, and a second connecting pipe assembly for detachably connecting the two adjacent fuel pipes is provided between them. Multiple fuel branch pipes (14) are evenly spaced around the fuel main pipe (11).

6. The double-walled fuel manifold according to claim 5, characterized in that, The second connector assembly includes a main pipe sleeve (16) and a main pipe straight connector (18) respectively fixed to the two adjacent fuel pipe ends, and a third outer nut (17). One end of the third outer nut (17) is limited and installed on the outer circle of the main pipe sleeve (16), and the other end is used to be threaded to the main pipe straight connector (18) so as to pull the two fuel pipe ends together during the tightening process.

7. The double-walled fuel manifold according to claim 5, characterized in that, The main heat insulation sleeve is formed by welding the left half heat insulation sleeve (3) and the right half heat insulation sleeve (4) which are split in half, and the right half heat insulation sleeve (4) has an extended branch pipe connection. The main heat insulation sleeve also includes multiple heat insulation sleeves arranged in a circumferential direction corresponding to multiple fuel pipes, and a third connecting pipe assembly for detachably connecting two adjacent heat insulation sleeves is provided.

8. The double-walled fuel manifold according to claim 7, characterized in that, The third connector assembly includes a sealing ring consisting of two sealing half-rings (19) split along the axial direction, a clamp washer (8) for sealing the gap between the two sealing half-rings (19), and a sealing clamp (9) for tightening the clamp washer (8) and the sealing ring. The sealing collar is fitted onto the outer circumference of the two adjacent insulation sleeve ends; The clamp washer (8) is fitted onto the outer circumference of the sealing collar; The sealing clamp (9) is detachably clamped to the outer circle of the clamp washer (8).

9. The double-walled fuel manifold according to claim 8, characterized in that, The inner ring cavity (1902) of the sealing sleeve half ring (19) is provided with a concave and semi-circular semi-circular fixing groove (1901) on each end of the wall surface. The outer circle of the sealing sleeve half ring (19) is also provided with a sealing ring groove (1903) that is axially spaced and concave and semi-circular. Two semi-circular fixing grooves (1901) are used to respectively hold the connecting rings that bulge outward on the outer circle of the two insulation sleeve ends; The sealing ring groove (1903) is used to mate with the clamp washer (8) to seal the gap between the two sealing sleeve half rings (19).

10. The double-walled fuel manifold according to claim 9, characterized in that, The clamp washer (8) is in the shape of a "C" with a notch. Its inner ring surface is provided with a sealing convex ring (803) that matches the sealing ring groove (1903). Its notch end face is also provided with a clamp fixing groove (801) that extends inward to penetrate the two end faces of the clamp washer (8). The sealing clamp (9) is inserted circumferentially into the clamp fixing groove (801), and both ends extend from the notch of the clamp washer (8) and are connected to the clamp locking pin.

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