Heat-proof load integrated high-temperature loop heat pipe combined with wing leading edge

Abstract

This invention belongs to the field of aircraft wing leading edge cooling and heat protection technology, and particularly relates to an integrated high-temperature loop heat pipe that is integrated with the leading edge of the wing for heat protection and load-bearing. It is installed at the leading edge of the wing and includes: an outer shell having the shape of a wing leading edge; and an inner shell located inside the outer shell. Both the outer and inner shells are V-shaped structures with a certain included angle, forming a V-shaped working fluid channel between them. A liquid wick is installed within the working fluid channel, which is filled with a cooling working fluid. A liquid downcomer is installed between the two arms of the inner shell. The liquid downcomer connects a radiative condensation zone and a storage zone, allowing the liquid working fluid in the radiative condensation zone to flow into the storage zone under gravity, and then flow back into the heated evaporation zone. The high-temperature loop heat pipe of this invention has the advantages of simple structure, convenient manufacturing, lightweight, high structural stability, and excellent thermal conductivity.

Description

Technical Field

[0001] This invention belongs to the field of cooling and heat protection technology for the leading edge of aircraft wings, and particularly relates to an integrated high-temperature loop heat pipe that is integrated with the leading edge of the wing for heat protection and load bearing. Background Technology

[0002] During flight, hypersonic vehicles typically operate at speeds exceeding Mach 5. As they move at high speeds through the dense atmosphere, the air experiences intense compression and friction, converting most of the vehicle's kinetic energy into heat. This causes a rapid increase in the surrounding air temperature, creating a significant temperature difference between the hot gas and the vehicle's surface. Some of the heat is rapidly transferred to the surface. This heating phenomenon caused by high-speed atmospheric flight is called aerodynamic heating, and its direct consequence is an increase in the surface and internal temperature of the vehicle. Particularly noteworthy is the rapid increase in surface temperature of sharp-shaped components such as the nose cone, wing leading edge, and aerodynamic control surfaces due to shock waves and viscosity, reaching over 1600°C. At such high temperatures, surface materials undergo various physical and chemical reactions, leading to a reduction or loss of functionality and severely impacting the vehicle's survivability, reusability, and the execution of tactical objectives. Therefore, thermal protection for these components is essential.

[0003] Currently, thermal protection for aircraft is mainly divided into passive thermal protection, active thermal protection, and semi-passive thermal protection. Passive thermal protection technology typically uses heat-resistant / insulating materials to cool critical structures. Its structure is relatively simple and reliable, and it can maintain the aerodynamic shape. However, under the high heat flux operating conditions of hypersonic aircraft engines, passive thermal protection technology has a limited capacity to withstand the total heat, and the temperature resistance limit of the materials can no longer meet the requirements. Active thermal protection technology mainly includes three cooling methods: sweating cooling, thin-film cooling, and convection cooling. This approach can achieve precise thermal control and is suitable for environments with high heat flux density. However, its structure and technology are more complex, which is not conducive to inspection, maintenance, and repair. Semi-passive thermal protection technologies include heat pipe structures and ablation structures. Among them, ablation structures have high thermal protection efficiency and strong adaptability, but the aerodynamic shape will change during the ablation process, which is not conducive to flight stability, and the ablation cooling technology cannot be reused. In the heat pipe structure, heat transfer is achieved through the phase change heat transfer of the working fluid and the flow between the evaporation section and the condensation section, and it can be reused. Therefore, it can be used for cooling sharp-shaped parts such as the nose cone, wing leading edge and aerodynamic rudder of the aircraft.

[0004] Currently, with the rise of a new wave of high-speed aircraft research and development, profound changes have occurred in aerodynamic shape, flight speed, flight environment, and flight time compared to traditional aircraft. Aircraft need to withstand prolonged aerodynamic thermal environments with high enthalpy and medium-low heat flux, while maintaining a high lift-to-drag ratio and a sharp leading edge shape. This places extremely stringent demands on the temperature resistance, durability, structure, efficiency, and reliability of heat protection materials. Faced with constraints such as ensuring survival under extremely high heat flux density and ultra-high temperature conditions, while also meeting requirements for structural stability, long-term operation, light weight, and reusability, semi-passive thermal protection technology using heat pipe structures offers significant advantages as a method for thermal protection of aircraft wing leading edges. This technology is simple and reliable, can be integrated into the aircraft design to reduce weight, possesses excellent heat dissipation capabilities, requires no dedicated energy supply, and is reusable.

[0005] Traditional heat pipe structures often employ an embedded approach, where multiple heat pipes are bent and embedded within the leading edge of the wing or other parts. This connection method leads to contact thermal resistance issues between the heat pipes and the wing, resulting in low heat transfer efficiency when heat generated by aerodynamic heating is conducted to the heat pipes. Furthermore, due to the small radius of the wing's leading edge, the diameter of the embedded heat pipes is often relatively small, limiting their heat transfer limit and making it difficult to meet the heat conduction requirements under aerodynamic heating conditions. In addition, since wings not only require thermal protection but also high strength, traditional heat pipe structures need to consider the arrangement of internal reinforcing ribs, leading to bending and deformation of the heat pipes and causing installation difficulties.

[0006] To meet the increasingly stringent quality requirements of hypersonic vehicles for structural and thermal protection systems, it is necessary to develop a mechanically and thermally integrated heat pipe thermal protection structure suitable for the leading edge of the wing, which combines structural stability, lightweight design, and efficient thermal conduction capabilities.

[0007] Research has been conducted on the application of high-temperature heat pipes to aerodynamic thermal protection of the leading edge of hypersonic aircraft wings. However, traditional integrated heat pipes are generally used in scenarios where localized areas are severely heated while adjacent areas are less affected. For components like the wing leading edge that require heat transfer to more distant areas, loop heat pipes are necessary. The most fundamental difference between loop heat pipes and traditional integrated heat pipes is that the loop heat pipe only has a wick in the evaporator. The wick draws the working fluid in only within the evaporator, while the liquid working fluid flows back through the smooth inner wall of the liquid pipe, significantly reducing the pressure drop. This allows heat to be transferred to more distant locations, making loop heat pipes more suitable for thermal protection of wing leading edges. Common types include cylindrical and flat loop heat pipes. In addition, in recent years, through continuous development by those skilled in the art, various types of irregularly shaped high-temperature heat pipes, such as hollow-shell high-temperature heat pipes and embedded high-temperature heat pipes, have also been developed. Therefore, for complex systems like hypersonic aircraft with extremely high weight and space requirements, the conductive high-temperature heat pipe protection technology has significant advantages.

[0008] In view of this, this invention addresses the design requirements of a heat-conducting integrated mechanical and thermal structure for the typical high heat flux region of hypersonic vehicles during long-distance flight with maximum dynamic pressure. It develops a heat-resistant, load-bearing integrated high-temperature loop heat pipe that is integrated with the leading edge of the wing. Summary of the Invention

[0009] The purpose of this invention is to develop a high-temperature loop heat pipe that integrates thermal protection and load-bearing capacity with the leading edge of the wing, which is designed to meet the requirements of thermal protection and thermal management schemes for high heat flux regions in hypersonic aircraft with high dynamic pressure and long-distance flight. This design combines lightweight, structural stability and efficient heat conduction capabilities.

[0010] This invention provides an integrated high-temperature loop heat pipe with thermal protection fused to the leading edge of an airfoil, which is disposed at the leading edge of the airfoil. The high-temperature loop heat pipe includes:

[0011] The outer shell has a wing-leading edge shape;

[0012] An inner housing, located inside the outer housing;

[0013] Both the outer shell and the inner shell are V-shaped structures with a certain included angle, forming a V-shaped working fluid flow channel between the outer shell and the inner shell. A liquid wick is provided in the working fluid flow channel, and the working fluid flow channel is filled with a cooling working fluid. The high-temperature loop heat pipe dissipates heat through the phase change of the working fluid and the flow of the working fluid in the working fluid flow channel.

[0014] A liquid downcomer is provided between the two arms of the inner housing;

[0015] Based on the state of the working fluid within the high-temperature loop heat pipe, the space within the working fluid flow channel is divided into:

[0016] The heated evaporation zone is located at the bend at the front end of the working fluid flow channel. The temperature of the heated evaporation zone is relatively high. The liquid working fluid is heated and evaporated in the heated evaporation zone to achieve phase change heat transfer and at the same time generate gaseous working fluid.

[0017] The steam rising zone is located in the middle of the channel above the working fluid channel, where the gaseous working fluid from the heated evaporation zone can rise further and flow into the steam rising zone.

[0018] The radiation condensation zone is located at the rear of the channel above the working fluid flow channel. The gaseous working fluid flows to the radiation condensation zone via the vapor rising zone and condenses into a liquid working fluid through radiation heat dissipation in the radiation condensation zone.

[0019] And a liquid storage area, which is located in the channel below the working fluid flow channel, the liquid downcomer connects the radiative condensation zone and the liquid storage area, so that the liquid working fluid in the radiative condensation zone can flow into the liquid storage area under the action of gravity, and then flow into the heated evaporation zone again.

[0020] Furthermore, a liquid-absorbing core is laid within the heated evaporation zone.

[0021] Alternatively, a liquid-absorbing core can be laid in the heated evaporation zone and the liquid storage zone.

[0022] Furthermore, the liquid-absorbing core has a grooved liquid-absorbing structure.

[0023] Furthermore, the liquid-absorbing core is disposed on the inner wall of the outer casing.

[0024] Furthermore, the high-temperature loop heat pipe also includes a support rib, which is disposed between the two arms of the inner shell.

[0025] Furthermore, a plurality of support ribs are provided between the two arms of the inner shell, and the cross-section of the support ribs is rectangular, circular or X-shaped.

[0026] Furthermore, the working fluid channel located in the radiation condensation zone is a channel that bends back and forth.

[0027] Furthermore, the filling rate of the working fluid in the working fluid channel is ≥60%, and the wall thickness of the outer shell is 5-10 mm.

[0028] Furthermore, the heated evaporation zone and / or liquid storage zone are provided with internal reinforcement structures.

[0029] Furthermore, the high-temperature loop heat pipe is manufactured as follows:

[0030] First, the outer shell and the inner shell are processed separately, and internal flow channels are processed on the outer shell and the inner shell by integral molding. When the outer shell and the inner shell are connected together, the internal flow channels on the outer shell and the inner shell can cooperate to form working fluid flow channels.

[0031] The outer shell and inner shell are then welded together using diffusion welding.

[0032] Finally, the liquid downcomer and supporting ribs are installed to form the high-temperature loop heat pipe.

[0033] or,

[0034] The high-temperature loop heat pipe is manufactured using metal 3D printing, and its material is high-temperature stainless steel alloy or niobium alloy powder.

[0035] The beneficial effects of this invention are:

[0036] 1. The high-temperature loop heat pipe designed in this invention separates the liquid pipeline and the vapor pipeline, that is, the design of the loop heat pipe realizes the co-directional flow of gas and liquid, which overcomes the limitations of traditional heat pipes in terms of application location and length;

[0037] 2. The most significant difference between the loop heat pipe designed in this invention and traditional heat pipes lies in the localized arrangement of the capillary wick structure. It only arranges the capillary wick in the heated evaporation zone, separating the capillary suction function from the liquid return function of the traditional heat pipe's capillary wick. This high-temperature loop heat pipe design allows the liquid to return to the storage chamber through a smooth inner wall pipe, instead of flowing through a highly resistant wick as in traditional heat pipes. This significantly reduces the flow pressure drop, greatly improving the capillary limit of the heat pipe and ensuring that the liquid working fluid can smoothly return to the storage zone and be continuously drawn to the evaporation heating surface, thus effectively preventing the heat pipe from drying out and failing.

[0038] 3. The present invention further lays interconnected wicks near both the heated evaporation zone and the liquid storage zone, so that the wicks in the liquid storage zone can be used as backups, so that the wicks of the heat pipe can contact the working fluid in the liquid storage zone at various tilt angles, thus meeting the stable operation requirements of the heat pipe under different flight attitudes and acceleration and deceleration.

[0039] 4. This invention fully integrates the design of the loop heat pipe with the leading edge structure of the wing, avoiding contact thermal resistance between the heat pipe and the shell, which can greatly improve the heat transfer of the heat pipe and realize the design concept of integrated heat protection and load-bearing functional structure.

[0040] 5. The loop heat pipe of the present invention is provided with multiple supporting and reinforcing structures, which can improve its structural strength and operational stability. Attached Figure Description

[0041] Figure 1 This is a three-dimensional structural schematic diagram of the high-temperature loop heat pipe described in this invention;

[0042] Figure 2 This is a schematic cross-sectional view of the high-temperature loop heat pipe described in this invention;

[0043] Figure 3 This is a schematic cross-sectional view of the liquid reflux channel in the high-temperature loop heat pipe of the present invention;

[0044] Figure 4 This is a schematic cross-sectional view of the high-speed steam flow channel in the high-temperature loop heat pipe described in this invention.

[0045] Figure 5 This is a schematic diagram showing the location division of each functional area in the high-temperature loop heat pipe described in this invention;

[0046] Figure 6 This is a schematic diagram of the gas-liquid flow state of the working fluid inside the loop heat pipe during normal flight of the aircraft;

[0047] Figure 7 This is a schematic diagram of the gas-liquid flow state of the working fluid inside the loop heat pipe when the aircraft is flying at a downward angle;

[0048] Figure 8 This is a schematic diagram of the gas-liquid flow state of the working fluid inside the loop heat pipe when the aircraft is flying at an angle of attack.

[0049] The markings in the diagram are as follows:

[0050] 1. Outer shell; 2. Inner shell; 3. Working fluid flow channel; 301. High-speed steam flow channel; 302. Liquid return channel; 4. Liquid downcomer; 5. Support rib; 6. Liquid suction core; 7. Heated evaporation zone; 8. Steam rising zone; 9. Radiative condensation zone; 10. Liquid storage zone. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0052] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0053] It should be noted that in the description of this application, the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0054] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0055] like Figures 1-5 As shown, a heat-resistant, integrated high-temperature loop heat pipe is fused with the leading edge of an airfoil and is disposed at the leading edge of the airfoil. The high-temperature loop heat pipe includes:

[0056] The outer shell 1 has a wing-leading edge shape;

[0057] Inner shell 2, which is located inside the outer shell 1;

[0058] Both the outer shell 1 and the inner shell 2 are V-shaped structures with a certain included angle. A V-shaped working fluid channel 3 is formed between the outer shell 1 and the inner shell 2. A liquid-absorbing core 6 is provided in the working fluid channel 3. The working fluid channel 3 is filled with a cooling working fluid. The high-temperature loop heat pipe dissipates heat through the phase change of the working fluid and the flow of the working fluid in the working fluid channel 3.

[0059] A liquid downcomer 4 is provided between the two arms of the inner housing 2.

[0060] Based on the state of the working fluid within the high-temperature loop heat pipe, the space within the working fluid channel 3 is divided into:

[0061] The heated evaporation zone 7 is located at the bend at the front end of the working fluid flow channel 3. The temperature of the heated evaporation zone 7 is relatively high. The liquid working fluid is heated and evaporated in the heated evaporation zone 7 to achieve phase change heat transfer and at the same time generate gaseous working fluid.

[0062] The steam rising zone 8 is located in the middle of the channel above the working fluid channel 3, where the gaseous working fluid from the heated evaporation zone 7 can rise further and flow into the steam rising zone 8.

[0063] The radiation condensation zone 9 is located at the rear of the channel above the working fluid flow channel 3. The gaseous working fluid flows to the radiation condensation zone 9 via the vapor rising zone 8 and condenses into a liquid working fluid through radiation heat dissipation in the radiation condensation zone 9.

[0064] And, the liquid storage area 10 is located in the channel below the working fluid flow channel 3, and the liquid downcomer 4 connects the radiation condensation zone 9 and the liquid storage area 10, so that the liquid working fluid in the radiation condensation zone 9 can flow into the liquid storage area 10 under the action of gravity.

[0065] The boundaries of the heated evaporation zone 7, the steam rising zone 8, the radiation condensation zone 9, and the liquid storage zone 10 can be determined by studying the state of the working fluid through experiments or monitoring, and the zones can be divided according to the state of the working fluid in the working fluid flow channel 3.

[0066] The working principle and process of the high-temperature loop heat pipe described in this invention are explained below:

[0067] During flight, the windward surface of the wing's leading edge encounters severe aerodynamic heat, and this area can serve as the evaporator of the heat pipe. The rear of the wing experiences less temperature rise and can radiate heat from the atmosphere, making this area a condenser for the heat pipe. For high-temperature loop heat pipes, the condenser needs to be higher than the evaporator to utilize gravity for liquid return. Therefore, in this invention, a vapor rising pipe is installed in the middle of the upper side of the wing's leading edge to form a vapor rising zone 8. The vapor rises and condenses into a liquid working fluid after reaching the radiative condensation zone 9. A liquid descending pipe 4 is installed between the upper and lower sides of the wing's leading edge to transport the returning liquid working fluid to the lower storage zone 10, thereby achieving the circulation of the working fluid within the working fluid flow channel 3, and thus achieving heat dissipation and cooling.

[0068] Furthermore, the liquid-absorbing core 6 is disposed within the heated evaporation zone 7.

[0069] Furthermore, the liquid-absorbing core 6 is disposed within the heated evaporation zone 7 and the liquid storage zone 10.

[0070] Preferably, a liquid-absorbing core 6 is laid in a continuous manner near both the heated evaporation zone 7 and the liquid storage zone 10. The liquid-absorbing core 6 in the liquid storage zone 10 can be used as a backup, so that the liquid-absorbing core 6 of the heat pipe can contact the working fluid in the liquid storage zone 10 at various tilt angles, which meets the stable operation requirements of the heat pipe under different flight attitudes and acceleration and deceleration.

[0071] Normally, the smooth return of liquid working fluid can be achieved solely by relying on the wick 6 within the heated evaporation zone 7. On this basis, the purpose of laying interconnected wicks 6 near both the heated evaporation zone 7 and the storage zone 10 is to allow the wicks 6 within the storage zone 10 to serve as backups. This ensures that the wicks 6 of the heat pipe can contact the working fluid in the storage zone 10 at various tilt angles, especially at extremely high elevation angles, thus meeting the stable operation requirements of the heat pipe under different flight attitudes and during acceleration and deceleration.

[0072] Preferably, the liquid-absorbing core 6 has a grooved liquid-absorbing structure.

[0073] Preferably, the liquid-absorbing core 6 is disposed on the inner wall of the outer shell 1.

[0074] The outer walls of the heated evaporation zone 7 and the liquid storage zone 10 can be provided with grooved liquid absorption structures to assist the heated evaporation zone 7 in absorbing liquid and avoid the problem of the evaporation surface drying out during extreme flight attitudes.

[0075] Furthermore, the high-temperature loop heat pipe also includes:

[0076] The support rib 5 is disposed between the two arms of the inner shell 2 and together with the liquid downcomer 4, forms the support structure of the high-temperature loop heat pipe to improve the structural stability of the high-temperature loop heat pipe.

[0077] Furthermore, multiple support ribs 5 can be provided, and their shape and size can be set according to the structural strength requirements.

[0078] As some examples of the present invention, the support ribs 5 can be provided in 3 to 8 forms; the shape of the support ribs 5, such as the cross-section, can be rectangular, circular, X-shaped, etc.

[0079] Furthermore, in the high-temperature loop heat pipe, the working fluid flows at high speed in a gaseous state within the working fluid channel 3 located in the vapor rising zone 8 and the radiative condensation zone 9. Therefore, the working fluid channel 3 located in the vapor rising zone 8 and the radiative condensation zone 9 is referred to as the high-speed vapor channel 301.

[0080] Furthermore, to accelerate radiative heat transfer and improve condensation efficiency, such as... Figure 4 As shown, the rear end of the high-speed steam flow channel 301, such as the high-speed steam flow channel 301 located in the radiative condensation zone 9, can be configured as a flow channel with back-and-forth bends. For example, the high-speed steam flow channel 301 located in the radiative condensation zone 9 can be U-shaped, S-shaped, or serpentine, etc. Along the flow direction of the working fluid, the end into the high-speed steam flow channel 301 is designated as its front end, and the other end as its end end. The end end of the high-speed steam flow channel 301 is connected to the liquid downcomer 4.

[0081] Preferably, the high-speed steam flow channel 301 located in the radiative condensation zone 9 is U-shaped.

[0082] In the high-temperature loop heat pipe of the present invention, a liquid return channel 302 is formed through the liquid downcomer 4, and the working fluid condensed in the radiative condensation zone 9 can flow into the liquid storage zone 10 through the liquid return channel 302 under the action of gravity.

[0083] Furthermore, Figures 6-8 A schematic diagram of the gas-liquid flow state of the working fluid within the high-temperature loop heat pipe of this invention is provided under different flight tilt angles of the aircraft. In this diagram, the red portion within the working fluid channel 3 represents the liquid working fluid, and the white portion represents the gaseous working fluid. Experiments have shown that when the filling rate of the working fluid within the working fluid channel 3 is ≥60%, and the thickness of the working fluid chamber within the high-temperature loop heat pipe, i.e., the wall thickness of the outer shell 1, is 5–10 mm, the peak heat flux density is ≥1 MW / m³. 2 Under these conditions, it can ensure that the heated surface of the wing leading edge is always wetted with liquid working fluid and does not dry out when the aircraft is in various flight attitudes.

[0084] Furthermore, the heated evaporation zone 7 and / or the liquid storage zone 10 can also be reinforced with internal structures to form a "sandwich" structure with the outer shell 1 and the inner shell 2 to improve the strength of the wing leading edge structure. For example, internal reinforcement structures such as honeycomb sandwich structures, corrugated plate sandwich structures, and lattice sandwich structures can be provided in the heated evaporation zone 7 and the liquid storage zone 10 to improve the structural strength of the wing leading edge.

[0085] As some examples of the present invention, the high-temperature loop heat pipe is processed as follows:

[0086] First, the outer shell 1 and the inner shell 2 are processed separately, and internal flow channels are processed on the outer shell 1 and the inner shell 2 by means of integral molding, etc. When the outer shell 1 and the inner shell 2 are connected together, the internal flow channels on the outer shell 1 and the inner shell 2 can cooperate to form the working fluid flow channel 3.

[0087] The outer shell 1 and the inner shell 2 are then welded together by diffusion welding.

[0088] Finally, by installing the liquid downcomer 4, support ribs 5, and other structures, the high-temperature loop heat pipe can be formed.

[0089] It should be noted that in the above-mentioned high-temperature loop heat pipe processing method, the diffusion welding process requires heating the welding chamber temperature to slightly higher than the melting point of the metal parts. Therefore, the selection of the liquid wick 6 structure should not use wire mesh or sintered metal powder. The grooved structure can be integrated with the metal shell, which is more convenient.

[0090] As further examples of the present invention, the high-temperature loop heat pipe can also be processed as follows:

[0091] The overall structure of the high-temperature loop heat pipe is processed by metal 3D printing, and its material is preferably high-temperature stainless steel alloy or niobium alloy powder.

[0092] However, it should be noted that this processing method is prone to clogging when processing fine structures such as the liquid-absorbing core 6. Therefore, the minimum printing size should generally exceed 500 micrometers.

[0093] Currently, traditional integrated high-temperature cylindrical heat pipes with a wick have established design methods, but high-temperature loop heat pipes lack a mature design standard and are subject to limited research. Furthermore, existing high-temperature loop heat pipes typically use sodium as the working fluid, with the wire mesh wick positioned on the inner wall of the liquid pipe, inside the condenser, and at the bottom of the evaporator, without a liquid receiver. This placement of the wick in multiple locations significantly increases the flow resistance of the working fluid, failing to leverage the inherent advantages of a loop heat pipe.

[0094] A typical loop heat pipe consists of an evaporator, a condenser, a liquid receiver, and steam and liquid lines. The most significant difference between a loop heat pipe and a traditional heat pipe lies in the arrangement of the capillary wick. The high-temperature loop heat pipe design described in this invention starts from the structural basis of a loop heat pipe and, in order to achieve an integrated heat protection / load-bearing effect, fully integrates the loop heat pipe with the leading edge structure of the wing. Combining the thermal protection requirements of the high-temperature loop heat pipe at the leading edge of a hypersonic vehicle wing, this invention innovatively proposes a high-temperature loop heat pipe that integrates heat protection / load-bearing with the leading edge of the wing. The capillary wick is arranged only in the evaporator, i.e., the heated evaporation zone 7, separating the capillary suction function and the liquid return function of the capillary wick in a traditional heat pipe. The liquid returns through the smooth inner wall of the liquid pipe, significantly reducing the flow pressure drop.

[0095] Most current high-temperature heat pipes adopt an integrated design of liquid and vapor lines (gas-liquid reverse flow). The high-temperature loop heat pipe designed in this invention separates the liquid and vapor lines, i.e., a loop heat pipe design (gas-liquid co-flow). This overcomes the limitations of traditional heat pipes in terms of application location and length. The most significant difference between the loop heat pipe designed in this invention and traditional heat pipes lies in the localized arrangement of the capillary wick structure. It only arranges the capillary wick in the heated evaporation zone 7, separating the capillary suction function of the traditional heat pipe's capillary wick from its liquid return function. This high-temperature loop heat pipe design allows the liquid to return to the storage chamber through the smooth inner wall of the line, instead of flowing through the highly resistant wick as in traditional heat pipes. This significantly reduces the flow pressure drop, greatly improving the capillary limit of the heat pipe and ensuring that the liquid working fluid can smoothly return to the storage zone and be continuously drawn to the evaporation heating surface, thereby effectively preventing the heat pipe from drying out and failing. Furthermore, this design is fully integrated with the wing leading edge structure, avoiding contact thermal resistance between the heat pipe and the shell, which can greatly improve the heat transfer of the heat pipe and realize the design concept of integrated heat protection and load-bearing functional structure.

[0096] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A heat-resistant, integrated high-temperature loop heat pipe fused to the leading edge of an airfoil, disposed at the leading edge of the airfoil, the high-temperature loop heat pipe comprising: The outer shell (1) has a wing leading edge shape; The inner shell (2) is located inside the outer shell (1); The outer shell (1) and the inner shell (2) are both V-shaped structures with a certain included angle. A V-shaped working fluid flow channel (3) is formed between the outer shell (1) and the inner shell (2). A liquid-absorbing core (6) is provided in the working fluid flow channel (3). The working fluid flow channel (3) is filled with a cooling working fluid. The high-temperature loop heat pipe dissipates heat through the phase change of the working fluid and the flow of the working fluid in the working fluid flow channel (3). Its features are, A liquid downcomer (4) is provided between the two arms of the inner shell (2); Based on the state of the working fluid within the high-temperature loop heat pipe, the space within the working fluid flow channel (3) is divided into: The heated evaporation zone (7) is located at the bend at the front end of the working fluid flow channel (3). The temperature of the heated evaporation zone (7) is relatively high. The liquid working fluid is heated and evaporated in the heated evaporation zone (7) to achieve phase change heat transfer and at the same time generate gaseous working fluid. The steam rising zone (8) is located in the middle of the channel above the working fluid channel (3), where the gaseous working fluid from the heated evaporation zone (7) can rise further and flow into the steam rising zone (8). The radiation condensation zone (9) is located at the rear of the channel above the working fluid flow channel (3). The gaseous working fluid flows to the radiation condensation zone (9) via the vapor rising zone (8) and condenses into a liquid working fluid through radiation heat dissipation in the radiation condensation zone (9). And, a liquid storage area (10) is located in the channel below the working fluid channel (3), and the liquid downcomer (4) connects the radiative condensation zone (9) and the liquid storage area (10), so that the liquid working fluid in the radiative condensation zone (9) can flow into the liquid storage area (10) under the action of gravity, and then flow into the heated evaporation zone (7) again.

2. The high-temperature loop heat pipe according to claim 1, characterized in that, A liquid-absorbing core (6) is laid in the heated evaporation zone (7). Alternatively, a liquid-absorbing core (6) can be laid in the heated evaporation zone (7) and the liquid storage zone (10).

3. The high-temperature loop heat pipe according to claim 1, characterized in that, The liquid-absorbing core (6) has a grooved liquid-absorbing structure.

4. The high-temperature loop heat pipe according to claim 1, characterized in that, The liquid-absorbing core (6) is disposed on the inner wall of the outer shell (1).

5. The high-temperature loop heat pipe according to claim 1, characterized in that, The high-temperature loop heat pipe also includes a support rib (5), which is disposed between the two arms of the inner shell (2).

6. The high-temperature loop heat pipe according to claim 5, characterized in that, A plurality of support ribs (5) are provided between the two arms of the inner shell (2), and the cross-section of the support ribs (5) is rectangular, circular or X-shaped.

7. The high-temperature loop heat pipe according to claim 1, characterized in that, The working fluid channel (3) located in the radiation condensation zone (9) is a channel that bends back and forth.

8. The high-temperature loop heat pipe according to claim 1, characterized in that, The filling rate of the working fluid in the working fluid channel (3) is ≥60%, and the wall thickness of the outer shell (1) is 5-10 mm.

9. The high-temperature loop heat pipe according to claim 1, characterized in that, The heated evaporation zone (7) and / or the liquid storage zone (10) are provided with internal reinforcement structures.

10. The high-temperature loop heat pipe according to claim 1, characterized in that, The high-temperature loop heat pipe is manufactured as follows: First, the outer shell and the inner shell are processed separately, and internal flow channels are processed on the outer shell and the inner shell by integral molding. When the outer shell and the inner shell are connected together, the internal flow channels on the outer shell and the inner shell can cooperate to form working fluid flow channels. The outer shell and inner shell are then welded together using diffusion welding. Finally, the liquid downcomer and supporting ribs are installed to form the high-temperature loop heat pipe. or, The high-temperature loop heat pipe is manufactured using metal 3D printing, and its material is high-temperature stainless steel alloy or niobium alloy powder.

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