A flexible, stretchable, one-piece heat pipe for thermal management

Abstract

This invention discloses a flexible, expandable, integrated heat pipe for thermal management, comprising an evaporator end, an adiabatic section, and a condenser end. Through a layered design, this invention suppresses the heat dissipation capacity of the heat pipe at low temperatures, and incorporates heat exchange fins on the outer side of the movable end to ensure heat transfer capacity. When the heat pipe temperature is lower than the start-up temperature, the movable end retracts into the adiabatic section, and the heat exchange fins engage with the retaining posts, also retracting into the adiabatic section. This allows for flexible adjustment of the heat exchange end volume, ensuring efficient heat exchange during operation and efficient heat preservation during rest. This invention integrates the expandable structure with the heat pipe into a single unit; the integrated structure is simple, low-cost, and allows for adjustment of design parameters according to operating conditions. The manufacturing process is mature.

Description

Technical Field

[0001] This invention relates to the field of heat pipe technology. Specifically, it relates to a flexible, stretchable, integrated heat pipe for thermal management. Background Technology

[0002] With the continuous reduction in size and increase in power density of equipment in various fields such as electronic devices, automobiles, and aerospace, the requirements for heat dissipation performance are also constantly increasing, making thermal management technology increasingly critical. Based on whether the thermal management process consumes additional energy, thermal management technologies are classified into active thermal management and passive thermal management technologies. Passive thermal management systems do not require external driving equipment such as fans and pumps, have a simple and compact system structure, are easy to maintain, and do not require complex active cooling system devices and control systems, resulting in relatively low overall costs. Therefore, passive thermal management technology has been widely used in thermal management of solar cells, lithium-ion batteries, electronic devices, power equipment, and various waste heat recovery scenarios. Currently, passive thermal management technologies mainly include heat pipes, thermal pads / thermal conductive materials, heat sinks, and thermal insulation technologies.

[0003] Heat pipes are simple and efficient heat transfer elements that do not require additional energy to operate and have been widely used in heat exchangers, aerospace, and energy storage system construction.

[0004] A typical heat pipe consists of a shell, a wick, and end caps. The inside of the heat pipe is evacuated to a negative pressure state and filled with a suitable liquid to adjust the boiling point of the filling liquid. The pipe wall has a wick, which is made of a capillary porous material. If the pipe wall does not have a wick, the effect of gravity must be considered. A heat pipe is mainly divided into an evaporator end, an adiabatic section, and a condenser end. When the evaporator end of the heat pipe is heated, the filling liquid rapidly vaporizes. Driven by thermal diffusion, the vapor flows through the adiabatic section to the condenser end, where it condenses and releases heat. The liquid then flows back to the evaporator end along the porous material via capillary action. This cycle continues until the temperatures at both ends of the heat pipe are equal (at which point thermal diffusion of the vapor stops). This cycle is rapid, and heat can be continuously conducted. This structure has remained unchanged since the manufacture and application of heat pipes.

[0005] However, the ultra-high thermal conductivity of heat pipes also presents challenges for their application in certain scenarios. For example, in lithium-ion battery thermal management systems, the battery pack needs high insulation capabilities in low-temperature environments to slow down the rate of battery temperature drop. For battery packs, due to requirements for compactness and efficient heat exchange, heat pipes in the battery thermal management system typically maintain close contact between the battery and the heat transfer medium to ensure efficient heat dissipation at the evaporation end. To ensure efficient condensation at the condensation end, the heat pipe at the condensation end needs to be fitted with metal fins to enhance heat dissipation. Even with insulation of the battery pack system, the evaporation end still loses more heat due to the large insulation area, which inhibits the battery pack's insulation capabilities in low-temperature environments.

[0006] For example, in a spacecraft, when the spacecraft is on the far side of the moon, the extremely low ambient temperature and vibration may cause the heat pipes to become brittle, break, and shatter. Therefore, during the spacecraft's hibernation period, it is necessary to enhance the insulation of the heat dissipation end of the heat pipe located on the outside of the spacecraft. However, the additional insulation structure and corresponding mechanical structure will increase the weight of the spacecraft and transportation costs. Therefore, the heat pipe itself needs to have insulation capabilities under such extreme conditions.

[0007] Meanwhile, multi-chamber segmented heat pipes have the disadvantages of complex structure and high manufacturing cost.

[0008] Current research has not yet yielded a heat pipe design that solves the aforementioned problems. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to provide a flexible, stretchable, integrated heat pipe for thermal management, which can control the length of the evaporation end and / or the condensation end, while enhancing the insulation performance in low-temperature environments.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a flexible, retractable, integrated heat pipe for thermal management, the heat pipe comprising a shell, an end cap, a flexible composite structure, a fixing ring, heat exchange fins, a strip-shaped metal button, and a retaining post; the shell has an accommodating cavity, and capillary wicks are disposed on the inner sides of the accommodating cavity and the end cap, the capillary wicks being tightly fitted to the walls of the accommodating cavity and the end cap; the flexible composite structure is cap-shaped, and a flexible capillary wick is disposed in its inner cavity, the flexible capillary wick being tightly fitted to the inner wall of the flexible composite structure; the fixing ring tightly connects the heat pipe and the flexible composite structure into a whole; the heat pipe and the flexible composite structure are not connected by the fixing ring. The port is sealed by an end cap made of the same material as the outer shell; the outer shell, end cap, flexible composite structure, and fixing ring are tightly connected, forming a closed cavity inside; the cavity is under negative pressure and filled with a certain proportion of liquid, the boiling temperature of which is the heat pipe start-up temperature; on the outer side of the flexible composite structure, along the axial direction connected to the outer side of the outer shell, a retaining post is installed pointing outwards from the flexible composite structure, the bottom end of which is tightly connected to the flexible composite structure; with the retaining post as the center, multiple heat exchange fins are installed on the outer side of the flexible composite structure; the bottom ends of the heat exchange fins are tightly connected to the strip-shaped metal button; the strip-shaped metal button is tightly connected to the flexible composite structure;

[0011] The flexible composite structure has an outer main body made of a flexible, highly sealing material, such as rubber or PET film.

[0012] The locking post, heat exchange fins, and strip-shaped metal button are made of high thermal conductivity rigid materials, such as metal, carbon fiber, and high thermal conductivity composite materials, which can be flexibly bent.

[0013] The outer shell and the fixing ring are tightly fastened together through processes such as nano-injection molding and hot melt riveting.

[0014] The flexible composite structure and the fixing ring are connected as a whole through processes such as hot melting, gluing, and integral molding.

[0015] The bottom end of the heat exchange fins is tightly connected to the strip-shaped metal button by welding, integral molding or other methods.

[0016] The pins and strip-shaped metal buttons are tightly connected to the flexible composite structure through vulcanization bonding, adhesive bonding, nano-injection molding and other methods.

[0017] The flexible capillary core covers the inner side of the fixing ring and is in close contact with the capillary core inside the outer shell.

[0018] The end cap and the outer shell can be tightly connected into a whole by welding or other means;

[0019] Optionally, the end cap may not be installed, and the outer shell can be sealed by means of extrusion welding, high-frequency heating sealing, or integral molding.

[0020] Optionally, the locking pin may not be installed;

[0021] Optionally, the heat exchange fins may not be installed;

[0022] Optionally, the strip-shaped metal button may not be installed;

[0023] The heat pipe is divided into an evaporation end, an adiabatic section, and a condensation end according to the circulation process of the liquid working fluid in the containment cavity. The evaporation end and condensation end of the heat pipe are divided into fixed type and movable type. The fixed type evaporation end and condensation end do not contain movable parts and are composed of the outer shell and the end cap tightly connected. The movable type is composed of the outer shell, the fixing ring and the flexible composite structure. The adiabatic section is the adiabatic section of the heat pipe and the sleeve, and the outer layer is coated with an insulating coating or installed with a heat insulation layer to isolate external heat exchange.

[0024] In this invention, at least one of the evaporation end and the condensation end is movable;

[0025] When the heat pipe temperature is lower than the heat pipe start-up temperature, the movable type will retract into the insulation section, the heat exchange fins will be engaged with the retaining post and also retract into the insulation section, and the heat pipe will stop working.

[0026] The active evaporator end will have a reserved heat absorption section to ensure the heat pipe can be started.

[0027] When the temperature of the heat pipe's working environment reaches or exceeds the start-up temperature, the liquid in the evaporator end will first absorb heat and boil to produce gas, allowing heat to be transferred to the condenser end through the insulation section. During this process, the outer shell, end cap, flexible composite structure, and fixing ring are tightly connected, and the pressure inside the cavity formed therein continuously rises, pushing the movable evaporator end and / or condenser end to extend out from inside the insulation section. The heat exchange fins unfold as the flexible composite structure extends, thereby accelerating the heat exchange rate.

[0028] When the temperature of the heat pipe falls below the heat pipe start-up temperature again, the liquid in the containment cavity condenses, and the pressure difference causes the movable evaporator end and / or condenser end to retract into the insulation section. The heat exchange fins are engaged with the retaining posts and also retract into the insulation section, and the heat pipe stops working.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. This invention reduces the heat dissipation capacity of the heat pipe under low-temperature conditions through a flexible structure design.

[0031] 2. This invention achieves flexible control of the heat pipe through the following method: when the heat pipe temperature is lower than the start-up temperature, the movable end retracts into the insulation section, and the heat exchange fins engage with the retaining posts and also retract into the insulation section. This enables flexible adjustment of the heat exchange end volume, ensuring efficient heat exchange during operation and efficient heat preservation during rest.

[0032] 3. This invention integrates the telescopic structure and the heat pipe into a whole, which is simple in structure, allows for adjustment of design parameters according to working conditions, and has a mature manufacturing process. Attached Figure Description

[0033] Figure 1 This is a diagram of the heat pipe structure in Embodiment 1 of the present invention;

[0034] Figure 2 This is an axial cross-sectional view of the heat pipe during the heat preservation stage in Embodiment 1 of the present invention;

[0035] Figure 3 This is an axial cross-sectional view of the heat pipe during the heat preservation stage in Embodiments 1 and 2 of the present invention, showing the condenser end shrinking into the insulation section.

[0036] Figure 4 This is an axial cross-sectional view of the connection between the insulation section and the condenser end heat pipe during the heat preservation stage in Embodiments 1 and 2 of the present invention.

[0037] Figure 5 This is an axial cross-sectional view of the heat pipe during the working stage of Embodiment 1 of the present invention;

[0038] Figure 6These are axial cross-sectional structural diagrams of the heat pipes at the adiabatic section and condenser end during the working stages of Embodiments 1 and 2 of the present invention;

[0039] Figure 7 This is an axial cross-sectional view of the heat pipe during the heat preservation stage in Embodiment 2 of the present invention;

[0040] Figure 8 This is an axial cross-sectional view of the heat pipe structure of the insulation section and the condenser end during the heat preservation stage in Embodiment 2 of the present invention;

[0041] Figure 9 This is an axial cross-sectional view of the heat pipe during the working stage of Embodiment 2 of the present invention;

[0042] Figure 10 This is an axial cross-sectional view of the heat pipe evaporator end during the working stage of Embodiment 2 of the present invention;

[0043] In the diagram, evaporator end 1; adiabatic section 2; condenser end 3;

[0044] Evaporating end capillary wick 11; Evaporating end outer shell 12; Insulation-evaporating end fixing ring 13; Evaporating end internal liquid filling 14; Evaporating end flexible composite structure 15; Evaporating end retaining post 16; Evaporating end heat exchange fins 17; Evaporating end flexible sealing film 151; Evaporating end flexible capillary wick 152; Evaporating end strip-shaped metal button 153;

[0045] 21. Capillary core of insulation section; 22. Outer shell of insulation section; 23. Fixing ring of insulation-condensation end; 24. Liquid filling inside insulation section;

[0046] 31. Flexible composite structure at the condensing end; 32. condensing end retaining post; 33. condensing end heat exchange fins; 311. Flexible sealing membrane at the condensing end; 312. Flexible capillary core at the condensing end; 313. Strip-shaped metal button at the condensing end. Detailed Implementation

[0047] Specific embodiments of the present invention are given below. These specific embodiments are only used to further illustrate the present invention in detail and do not limit the scope of protection of the claims of the present invention.

[0048] Example 1:

[0049] Please see Figure 1-6 The present invention provides an embodiment of a flexible, retractable, integrated heat pipe for thermal management, comprising an evaporating end 1; an insulating section 2; a condensing end 3; an evaporating end internal liquid filling 14; an evaporating end capillary 11; an evaporating end outer shell 12; an insulating section capillary 21; an insulating section outer shell 22; an insulating-condensing end fixing ring 23; a condensing end flexible composite structure 31; a condensing end retaining post 32; condensing end heat exchange fins 33; a condensing end flexible sealing film 311; a condensing end flexible capillary 312; and a condensing end strip-shaped metal button 313.

[0050] The evaporator end shell 12, the insulation section shell 22, the insulation-condensation end fixing ring 23, and the condensation end flexible composite structure 31 form an integral cavity. An evaporator end capillary 11, an insulation section capillary 21, and a condensation end flexible capillary 312 are respectively disposed inside the cavity. These capillary wicks are tightly fitted to the inner wall of the cavity. The cavity is under negative pressure and filled with a certain proportion of liquid, i.e., the evaporator end is filled with liquid 14. The boiling temperature of this liquid within the cavity is the heat pipe start-up temperature. The outer side of the condensation end flexible composite structure 31 is connected to the condensation end flexible composite structure. The axial direction of the insulating section shell 22 connected to the outside of the structure 31 points to the outside of the flexible composite structure 31 at the condensing end. A condensing end retainer 32 is installed thereon, and the bottom end of the condensing end retainer 32 is tightly connected to the flexible sealing membrane 311 at the condensing end. With the condensing end retainer 32 as the center, multiple condensing end heat exchange fins 33 are installed on the outside of the flexible composite structure 31 at the condensing end. The bottom end of the condensing end heat exchange fins 33 is tightly connected to the strip-shaped metal button 313 at the condensing end. The strip-shaped metal button 313 at the condensing end is tightly connected to the flexible sealing membrane 311 at the condensing end.

[0051] The flexible sealing membrane 311 at the condensation end is made of rubber.

[0052] The condensing end retainer 32, the condensing end heat exchange fins 33 and the condensing end strip metal button 313 are made of aluminum alloy and can be flexibly bent.

[0053] The heat insulation section shell 22 and the heat insulation-condensation end fixing ring 23 are tightly fastened together by nano-injection molding process;

[0054] The flexible composite structure 31 at the condensing end and the heat insulation-condensing end fixing ring 23 are connected as a whole by a heat fusion process.

[0055] The bottom end of the heat exchange fin 33 at the condensing end and the strip-shaped metal button 313 at the condensing end are tightly connected by an integral molding method.

[0056] The condenser end retaining post 32 and the condenser end strip metal button 313 are tightly connected to the condenser end flexible composite structure 31 by vulcanization bonding.

[0057] The flexible capillary 312 at the condensing end covers the inner side of the heat insulation-condensing end fixing ring 23 and is in close contact with the capillary 21 at the heat insulation section.

[0058] The outer side of the insulating section shell 22 is coated with an insulating coating.

[0059] Initially, the heat pipe temperature is lower than the heat pipe start-up temperature, and the condensing end 3 retracts into the insulation section 2. The flexible sealing film 311 of the condensing end is tightly connected to the insulation-condensing end fixing ring 23. The flexible sealing film 311 of the condensing end undergoes elastic bending and retracts into the insulation section 2. The heat exchange fins 33 of the condensing end are engaged with the condensing end retaining post 32. As the flexible sealing film 311 of the condensing end also retracts into the insulation section 2, the heat pipe stops working.

[0060] When the temperature of the evaporator end 1 of the heat pipe reaches or exceeds the start-up temperature, the internal filling liquid 11 in the evaporator end 1 boils and produces gas. The generated steam carries heat and passes through the insulation section 2 to reach the flexible composite structure 31 of the condenser end 3. Because the flexible composite structure 31 of the condenser end is contracted inside the insulation section 2, it cannot dissipate the heat in time. The heat accumulates inside the heat pipe, causing the pressure inside the heat pipe cavity to rise continuously. This pushes the condenser end 3 to extend out from inside the insulation section 2. The heat exchange fins 33 of the condenser end extend along with the flexible composite structure 31 of the condenser end. The extension and unfolding accelerate the heat exchange rate; the condensing end retainer 32, the condensing end heat exchange fins 33, the condensing end flexible sealing film 311 and the condensing end strip metal button 313 exchange heat with the surrounding environment, so that the steam reaching the inside of the condensing end 3 condenses on the condensing end flexible capillary 312. After condensation, the liquid filling 14 in the evaporating end extends along the condensing end flexible capillary 312, passes through the adiabatic section capillary 21 and the evaporating end capillary 11, and returns to the liquid filling 14 in the evaporating end to absorb heat and evaporate again, thereby realizing the continuous transfer of heat;

[0061] When the temperature of the evaporation end 1 is lower than the heat pipe start-up temperature again, the boiling and gas production of the internal filling liquid 11 in the evaporation end 1 slows down, which reduces the heat transferred to the surrounding environment through the condensation end 3 per unit time. The gas produced by boiling in the internal cavity of the heat pipe continues to condense, causing the pressure in the internal cavity of the heat pipe to drop continuously until it is lower than the preset threshold. Under the action of the internal and external pressure difference, the condensation end 3 shrinks into the insulation section 2, and the condensation end heat exchange fins 33 are engaged with the condensation end retaining post 32. As the condensation end flexible sealing film 311 also shrinks into the insulation section 2, the heat pipe stops working.

[0062] Example 2:

[0063] Please refer to 1, 3, 4, 6-10 for an embodiment of the present invention: a flexible, retractable, integrated heat pipe for thermal management, comprising: an evaporator end 1; an adiabatic section 2; a condenser end 3; an evaporator end capillary 11; an evaporator end outer shell 12; an adiabatic-evaporator end fixing ring 13; an evaporator end internal liquid filling 14; an evaporator end flexible composite structure 15; an evaporator end retaining post 16; an evaporator end heat exchange fin 17; an adiabatic section capillary 21; an adiabatic section outer shell 22; an adiabatic-condenser end fixing ring 23; an adiabatic section internal liquid filling 24; a condenser end flexible composite structure 31; a condenser end retaining post 32; a condenser end heat exchange fin 33; an evaporator end flexible sealing film 151; an evaporator end flexible capillary 152; an evaporator end strip-shaped metal button 153; a condenser end flexible sealing film 311; a condenser end flexible capillary 312; and a condenser end strip-shaped metal button 313.

[0064] The evaporator end shell 12, the heat insulation-evaporator end fixing ring 13, the evaporator end flexible composite structure 15, the heat insulation section shell 22, the heat insulation-condenser end fixing ring 23, and the condenser end flexible composite structure 31 form an integral housing cavity. The housing cavity is provided with an evaporator end capillary 11, a heat insulation section capillary 21, an evaporator end flexible capillary 152, and a condenser end flexible capillary 312. The capillary 11 is tightly attached to the inner wall of the housing cavity. The housing cavity is under negative pressure and filled with a certain proportion of liquid, namely, liquid filling 14 in the evaporator end and liquid filling 24 in the heat insulation section. The boiling temperature of this liquid in the housing cavity is the heat pipe start-up temperature.

[0065] On the outer side of the flexible composite structure 31 at the condensing end, the axial direction of the insulating section shell 22 connected to the outer side of the flexible composite structure 31 at the condensing end is pointing towards the outer side of the flexible composite structure 31 at the condensing end. A condensing end retainer 32 is installed, and the bottom end of the condensing end retainer 32 is tightly connected to the flexible sealing membrane 311 at the condensing end. With the condensing end retainer 32 as the center, multiple condensing end heat exchange fins 33 are installed on the outer side of the flexible composite structure 31 at the condensing end. The bottom end of the condensing end heat exchange fins 33 is tightly connected to the strip-shaped metal button 313 at the condensing end. The strip-shaped metal button 313 at the condensing end is tightly connected to the flexible sealing membrane 311 at the condensing end.

[0066] On the outer side of the flexible composite structure 15 at the evaporator end, the axial direction of the evaporator end outer shell 12 connected to the outer side of the flexible composite structure 15 at the evaporator end is pointing towards the outer side of the flexible composite structure 15 at the evaporator end. An evaporator end retainer 16 is installed, and the bottom end of the evaporator end retainer 16 is tightly connected to the flexible sealing film 151 at the evaporator end. With the evaporator end retainer 16 as the center, multiple evaporator end heat exchange fins 17 are installed on the outer side of the flexible composite structure 15 at the evaporator end. The bottom end of the evaporator end heat exchange fins 17 is tightly connected to the strip-shaped metal button 153 at the evaporator end. The strip-shaped metal button 153 at the evaporator end is tightly connected to the flexible sealing film 151 at the evaporator end.

[0067] The flexible sealing membrane 151 at the evaporation end and the flexible sealing membrane 311 at the condensation end are made of rubber.

[0068] The evaporator end retainer 16, evaporator end heat exchange fins 17, evaporator end strip metal button 153, condenser end retainer 32, condenser end heat exchange fins 33 and condenser end strip metal button 313 are made of aluminum alloy and can be flexibly bent.

[0069] The heat insulation section shell 22 and the heat insulation-condensation end fixing ring 23 are tightly fastened together by nano-injection molding process;

[0070] The evaporator end shell 12 and the heat insulation-evaporator end fixing ring 13 are tightly fastened together by nano-injection molding process;

[0071] The flexible composite structure 31 at the condensing end and the heat insulation-condensing end fixing ring 23 are connected as a whole by a heat fusion process.

[0072] The flexible composite structure 15 at the evaporation end and the heat insulation-evaporation end fixing ring 13 are connected as a whole by a heat fusion process.

[0073] The bottom end of the heat exchange fin 33 at the condensing end and the strip-shaped metal button 313 at the condensing end are tightly connected by an integral molding method.

[0074] The bottom end of the evaporator end heat exchange fin 17 and the evaporator end strip metal button 153 are tightly connected by an integral molding method;

[0075] The condenser end retaining post 32 and the condenser end strip metal button 313 are tightly connected to the condenser end flexible composite structure 31 by vulcanization bonding.

[0076] The evaporator end retaining post 16 and the evaporator end strip metal button 153 are tightly connected to the evaporator end flexible composite structure 15 by vulcanization bonding.

[0077] The flexible capillary 312 at the condensing end covers the inner side of the heat insulation-condensing end fixing ring 23 and is in close contact with the capillary 21 at the heat insulation section.

[0078] The flexible capillary 152 at the evaporation end covers the inner side of the heat insulation-evaporation end fixing ring 13 and is in close contact with the capillary 11 at the evaporation end.

[0079] The outer side of the insulating section shell 22 is coated with an insulating coating.

[0080] Initially, the heat pipe temperature is lower than the heat pipe start-up temperature. The evaporator end 1 and the condenser end 3 retract into the insulation section 2. The flexible sealing film 151 at the evaporator end is tightly connected to the insulation-evaporator end fixing ring 13. The flexible sealing film 151 at the evaporator end undergoes elastic bending and retracts into the insulation section 2. The heat exchange fins 17 at the evaporator end are engaged with the evaporator end retainer 16. As a result, the flexible sealing film 151 at the evaporator end also retracts into the insulation section 2. The flexible sealing film 311 at the condenser end is tightly connected to the insulation-condenser end fixing ring 23. The flexible sealing film 311 at the condenser end undergoes elastic bending and retracts into the insulation section 2. The heat exchange fins 33 at the condenser end are engaged with the condenser end retainer 32. As a result, the flexible sealing film 311 at the condenser end also retracts into the insulation section 2. At this time, the heat pipe stops working.

[0081] When the temperature of the heat pipe evaporator end 1 reaches or exceeds the start-up temperature, the liquid 14 inside the evaporator end 1 boils and produces gas. The generated steam carries heat and passes through the insulation section 2 to reach the flexible composite structure 31 of the condenser end 3. Because the flexible composite structure 31 of the condenser end is contracted inside the insulation section 2, it cannot dissipate heat in time, and heat accumulates inside the heat pipe, causing the pressure inside the heat pipe cavity to rise continuously. This pushes the evaporator end 1 and the condenser end 3 to extend out from inside the insulation section 2. The heat exchange fins 17 of the evaporator end and the heat exchange fins 33 of the condenser end unfold as the flexible composite structure 15 of the evaporator end and the flexible composite structure 31 of the condenser end extend, thereby accelerating the heat exchange rate. (Evaporator end shell 12, evaporator end retaining post 16) Evaporator end heat exchange fins 17, evaporator end flexible sealing film 151, and evaporator end strip metal button 153 absorb heat from the surrounding environment, causing the liquid filling 14 in the evaporator end and the liquid filling 24 in the adiabatic section to boil; condenser end retainer 32, condenser end heat exchange fins 33, condenser end flexible sealing film 311, and condenser end strip metal button 313 exchange heat with the surrounding environment, causing the steam reaching the inside of the condenser end 3 to condense on the condenser end flexible capillary 312. After condensation, the liquid filling 14 in the evaporator end and the liquid filling 24 in the adiabatic section extend along the condenser end flexible capillary 312, through the adiabatic section capillary 21 and the evaporator end capillary 11, and return to the liquid filling 14 in the evaporator end and the liquid filling 24 in the adiabatic section, absorbing heat and evaporating again, thereby realizing the continuous transfer of heat.

[0082] When the temperature of the evaporator end 1 falls below the heat pipe start-up temperature again, the boiling and gas production of the internal filling liquid 11 in the evaporator end 1 slows down, which reduces the heat transferred to the surrounding environment through the condenser end 3 per unit time. The gas produced by boiling in the internal cavity of the heat pipe continues to condense, causing the pressure in the internal cavity of the heat pipe to drop continuously until it falls below the preset threshold. Under the action of the internal and external pressure difference, the evaporator end 1 and the condenser end 3 contract into the insulation section 2. The heat exchange fins 17 of the evaporator end are engaged with the evaporator end retainer 16. As the flexible sealing film 151 of the evaporator end contracts into the insulation section 2, the heat exchange fins 33 of the condenser end are engaged with the condenser end retainer 32. As the flexible sealing film 311 of the condenser end also contracts into the insulation section 2, the heat pipe stops working.

[0083] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A flexible and retractable integrated heat pipe for thermal management, comprising a shell, an end cap, a flexible composite structure, a fixing ring buckle, heat exchange fins, a strip-shaped metal button and a clamping column, wherein a containing cavity is formed in the shell, a capillary core is arranged on the inner side of the containing cavity and the end cap, and the capillary core is tightly attached to the wall surface of the containing cavity and the end cap; the flexible composite structure is in the shape of a cap, and a flexible capillary core is arranged in the inner cavity of the flexible composite structure, and the flexible capillary core is tightly attached to the inner cavity wall surface of the flexible composite structure; the fixing ring buckle tightly connects the heat pipe and the flexible composite structure as a whole; the port not connected by the fixing ring buckle is sealed by an end cap made of the same material as the shell; the shell, the end cap, the flexible composite structure and the fixing ring buckle are tightly connected, and a closed cavity is formed inside; the containing cavity is under negative pressure and filled with a liquid in a certain proportion, and the boiling temperature of the liquid in the containing cavity is the starting temperature of the heat pipe; a clamping column is installed on the outer side of the flexible composite structure and the shell connected to the outer side of the flexible composite structure in the axial direction and pointing to the outer side of the flexible composite structure, and the bottom end of the clamping column is tightly connected to the flexible composite structure; a plurality of heat exchange fins are installed on the outer side of the flexible composite structure with the clamping column as the center; the bottom end of the heat exchange fins is tightly connected to the strip-shaped metal button; and the strip-shaped metal button is tightly connected to the flexible composite structure. When the temperature of the evaporation end of the heat pipe reaches the starting temperature or above, heat is accumulated inside the heat pipe, causing the pressure in the containing cavity inside the heat pipe to rise, which pushes the condensation end to extend from inside the adiabatic section, and the heat exchange fins of the condensation end are unfolded along with the extension of the flexible composite structure of the condensation end. When the temperature of the heat pipe is lower than the starting temperature of the heat pipe, the movable part is retracted into the adiabatic section, the heat exchange fins are clamped on the clamping column and also retracted into the adiabatic section, and the heat pipe stops working. The outer side of the flexible composite structure is made of flexible and high-sealing material selected from rubber or PET film; the clamping column, the heat exchange fins and the strip-shaped metal button are made of high-thermal-conductivity hard material capable of elastic bending, selected from metal, carbon fiber material or high-thermal-conductivity composite material; the shell and the fixing ring buckle are tightly connected by nano-injection molding or hot-melt riveting process; the flexible composite structure and the fixing ring buckle are connected as a whole by hot-melt bonding, gluing or one-piece forming process; the bottom end of the heat exchange fins and the strip-shaped metal button are tightly connected by welding or one-piece forming; the clamping column and the strip-shaped metal button are tightly connected to the flexible composite structure by vulcanization bonding, gluing or nano-injection molding; the flexible capillary core covers the inner side of the fixing ring buckle and is in tight contact with the capillary core on the inner side of the shell; and the end cap and the shell can be tightly connected as a whole by welding.

2. A flexible and scalable integrated heat pipe for thermal management according to claim 1, wherein: The shell is sealed at the end by extrusion welding, high-frequency heating sealing or one-piece forming.

3. A flexible and scalable integrated heat pipe for thermal management according to claim 1, wherein: ​ 4. A flexible and scalable integrated heat pipe for thermal management according to claim 1, wherein: The heat pipe is divided into an evaporation end, an adiabatic section and a condensation end according to the circulation process of the liquid working medium in the accommodating cavity, the evaporation end of the heat pipe is a fixed type which is tightly connected by the shell and the end cover; the condensation end is a movable type which is composed of the shell, a fixed ring buckle and a flexible composite structure; the outer layer of the adiabatic section is coated with an adiabatic coating or is provided with a heat preservation layer to isolate the heat exchange with the outside.

5. A flexible and scalable integrated heat pipe for thermal management according to claim 4, wherein: The movable evaporation end is provided with a heat absorption part to ensure that the heat pipe can be started.

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