HEAT PIPE CAPABLE OF PREVENTING FREEZING AND EXPANDING

Abstract

 This application provides a heat pipe for preventing icing expansion. The heat pipe includes a pipe body having a sealed cavity, and a heat transfer medium and a capillary structure are disposed in the sealed cavity. The pipe body includes a main pipe section and a first additional pipe section, where the main pipe section includes an evaporation section, a heat insulation section, and a condensation section that are sequentially connected, the first additional pipe section is connected to an end part of the evaporation section, and a first additional cavity is disposed in the first additional pipe section. The first additional cavity is used to accommodate all or a part of the heat transfer medium when the heat pipe is vertically placed and the first additional pipe section is located below a gravity direction, and when the heat pipe is mounted on a heat dissipation device that requires heat dissipation, the first additional pipe section is not in contact with a heat emitting component of the heat dissipation device. Because the first additional pipe section is not in contact with the heat emitting component of the heat dissipation device, even if the first additional pipe section expands and deforms due to freezing of the internal heat transfer medium, stability of contact between the heat pipe and a heat dissipation component is not affected, thereby ensuring reliable heat dissipation performance of the heat dissipation device.

Description

[0001] This application claims priority to Chinese Patent Application No. 202210159473.0, filed with the China National Intellectual Property Administration on February 21, 2022 and entitled "HEAT PIPE FOR PREVENTING ICING EXPANSION", which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] This application relates to the field of heat dissipation technologies, and in particular, to a heat pipe for preventing icing expansion, a heat dissipation module including the heat pipe, and a heat dissipation device.

BACKGROUND

[0003] A heat pipe (heat pipe, HP) has features such as ultra-silence, a high heat conductivity, a light weight, a small size, and a simple structure, and is widely applied to a heat dissipation field of electronic devices with high heat flux density, such as a router and a server. A basic structure of the heat pipe is that a capillary structure layer that easily absorbs working liquid is disposed on an inner wall of a sealed pipe, central space of the sealed pipe is in a void state, and the working liquid is injected into the sealed pipe that is vacuumized, to implement heat transfer through a cyclic phase change of the working liquid. To improve heat dissipation efficiency, the heat pipe is usually combined with a heat sink, and heat is dissipated for a heat emitting element (for example, a chip) in a heat dissipation device in a form of a heat dissipation module.

[0004] The heat pipe may be in a low-temperature environment in a process of using, storing, assembling, or transporting the heat pipe. In this case, a working substance (for example, water) inside the heat pipe may freeze. When mechanical strength of the heat pipe is insufficient to resist expansion force generated due to an increase in volume caused by freezing of the working substance, the heat pipe expands and deforms. In this case, contact between the heat pipe and the heat sink may be affected, an air gap is easily generated at a joint between the heat pipe and the heat sink and heat transfer resistance is increased, and the heat pipe is even separated from the heat sink. As a result, heat dissipation performance of the entire heat dissipation device deteriorates or even the heat dissipation device fails.

SUMMARY

[0005] This application provides a heat pipe for preventing icing expansion. A first additional pipe section is disposed at an end of the heat pipe. The first additional pipe section has a first additional cavity therein configured to accommodate a heat transfer medium and allow the heat transfer medium to ice and expand. During use after mounting, the first additional pipe section is not in contact with a heat emitting component of a heat dissipation device. In this case, even if the first additional pipe section expands and deforms due to freezing of the internal heat transfer medium, stability of contact between the heat pipe and the heat emitting component is not affected, thereby ensuring reliable heat dissipation performance of the heat dissipation device.

[0006] According to a first aspect, this application provides a heat pipe for preventing icing expansion, including a pipe body having a sealed cavity, where a heat transfer medium and a capillary structure are disposed in the sealed cavity, and the pipe body includes: a main pipe section, where the main pipe section is sequentially divided into an evaporation section, a heat insulation section, and a condensation section in a length direction, and the capillary structure is located at least in a heat exchange cavity of the main pipe section; and a first additional pipe section, where the first additional pipe section is connected to an end part of the evaporation section, a first additional cavity is disposed in the first additional pipe section, the first additional cavity is used to accommodate all or a part of the heat transfer medium when the heat pipe is vertically placed and the first additional pipe section is located below a gravity direction, and when the heat pipe is mounted on a heat dissipation device that requires heat dissipation, the first additional pipe section is not in contact with a heat emitting component of the heat dissipation device.

[0007] The heat pipe provided in this embodiment of this application includes the main pipe section and the first additional pipe section. The first additional pipe section is disposed at an end of the main pipe section, which means to add the first additional pipe section to a conventional heat pipe. When the heat pipe is used after being mounted, the evaporation section in the main pipe section is in contact with the heat emitting component like a heat source or a heat sink in the heat dissipation device to perform heat transfer, and the first additional pipe section is not used as the evaporation section or the condensation section, that is, the first additional pipe section is not in contact with (for example, attached to) the heat emitting component.

[0008] The first additional pipe section is disposed at the end part of the evaporation section and has the first additional cavity therein, so that when the heat pipe is vertically placed and the first additional pipe section is placed at the bottom, the part of the heat transfer medium is separated from the capillary structure due to gravity and gathers in the first additional cavity. The first additional cavity has a sufficient volume to accommodate the heat transfer medium and allow the heat transfer medium to ice and expand.

[0009] When the heat pipe provided in this embodiment of this application is used in the heat dissipation device, even if the first additional pipe section deforms to some extent due to the icing expansion, because the first additional pipe section is not in contact with the heat emitting component (for example, the heat source or the heat sink) in the heat dissipation device, stability of contact between the evaporation section and the heat emitting component is not affected, so that the evaporation section can always be stably and reliably connected to the heat emitting component, no air gap is generated at a joint between the evaporation section and the heat emitting component, and heat dissipation performance of the heat dissipation device is not adversely affected. This ensures that the heat pipe provided in this embodiment of this application has reliable use stability, and meets a use requirement of the heat dissipation device in a low-temperature condition. Therefore, it is also convenient to perform operations such as usage, storage, assembly, and transportation on the heat pipe. In this case, the heat pipe can be vertically placed in a transportation process, and the first additional pipe section is disposed at the bottom.

[0010] Optionally, the heat dissipation device herein may be various devices that require heat dissipation, for example, may be an electronic device. The electronic device may be a network device like a router, a server, a switch, or a communication base station, or may be a terminal device like a mobile phone, a notebook computer, a desktop computer, or a vehicle-mounted device.

[0011] In a possible implementation, the heat dissipation device may alternatively be a vehicle (for example, an electric vehicle), that is, heat is dissipated for a heat emitting component on the vehicle by using the heat pipe.

[0012] Optionally, the heat emitting component herein may be various components (namely, heat sources, for example, various chips or circuits) that can emit heat and that are inside the heat dissipation device, or may be an indirect (intermediate) heat transfer component (for example, a heat sink) configured to transfer heat of the heat source.

[0013] Optionally, the pipe body is made of a material with a good heat-conducting property, for example, may be made of a copper material, or may be made of another material, for example, aluminum, steel, carbon steel, stainless steel, iron, nickel, titanium and alloys thereof, or a polymer material with a good heat-conducting property, based on a different requirement. However, this is not limited thereto.

[0014] Optionally, the pipe body may be of an integrated structure made by using an integrated molding process, or may be formed by sequentially splicing (for example, welding) a plurality of pipe sections. The plurality of pipe sections may be made of a same material or different materials. For example, both the evaporation section and the condensation section may be made of a metal material, and the heat insulation section may be made of a non-metal material. For example, the heat insulation section may be made of at least one of polymer materials such as plastic, resin, rubber, and synthetic fiber. In this case, material costs of the heat pipe can be saved, a weight of the heat pipe can be light, and the heat insulation section can have good heat insulation performance.

[0015] Optionally, the heat pipe may further be flexible and bendable. In this case, the heat pipe may be used in a foldable electronic device (for example, a mobile phone or a tablet computer). In this case, the heat insulation section may be made of a material like flexible graphite, flexible rubber, or flexible resin. For example, the heat insulation section may be made of a flexible polymer material like polyimide (polyimide, PI), polyethylene terephthalate, or polyethylene naphthalate.

[0016] Optionally, the capillary structure may be of any type like a groove type, a sintered powder type, a fiber type, a grid type, or a honeycomb type. However, this is not limited thereto.

[0017] Optionally, the heat transfer medium may be one or a mixture of water, methanol, ethanol, acetone, liquid ammonia, heptane, or the like.

[0018] Optionally, the first additional pipe section and the main pipe section may form the pipe body by using the integrated molding process, or may be used as two separate pipe sections that are interconnected (for example, sealed welding) to form the pipe body. This is not limited in this application.

[0019] In a possible design, when the heat pipe is vertically placed and the first additional pipe section is located below the gravity direction, the first additional cavity can accommodate all heat transfer medium that cannot be maintained inside the capillary structure.

[0020] In other words, the first additional cavity has a sufficient volume to accommodate the heat transfer medium, to ensure that the heat transfer medium does not overflow into the evaporation section when the heat pipe is vertically placed, thereby avoiding deformation of the evaporation section due to the icing expansion of the working substance. This ensures that the evaporation section can always be stably and reliably connected to the heat emitting component, and ensures that the heat pipe has stable and reliable heat dissipation performance.

[0021] In a possible design, the pipe body further includes: a second additional pipe section, where the second additional pipe section is connected to an end part of the condensation section, a second additional cavity is disposed in the second additional pipe section, and the second additional cavity is used to accommodate the all or the part of the heat transfer medium when the heat pipe is vertically placed and the second additional pipe section is located below the gravity direction.

[0022] In other words, each of two end parts of the main pipe section is connected to an additional pipe section, that is, the first additional pipe section is connected to the evaporation section, the second additional pipe section is connected to the condensation section, and the sealed cavity includes the first additional cavity, the second additional cavity, and the heat exchange cavity. An advantage of the disposing is that, in this case, any end part of the heat pipe has the additional cavity that allows the icing expansion of the heat transfer medium, and the heat pipe has strong adaptability. When the heat pipe is vertically placed for use, transportation, or storage, an operator may dispose any end part of the heat pipe at the bottom without selection, so that a step of discrimination is omitted, thereby improving operation efficiency.

[0023] Optionally, in another implementation, the heat pipe may include only one additional pipe section. In this case, the only additional pipe section may be disposed at any end part of the main pipe section. For example, the additional pipe section may be connected to the evaporation section, or connected to the condensation section, and the other end part of the main pipe section that is not provided with the additional pipe section is sealed.

[0024] In a possible design, a cross-sectional area of the first additional cavity is greater than a cross-sectional area of the heat exchange cavity. Because the first additional cavity has a larger cross-sectional area, the first additional pipe section can be disposed shorter on the premise that a capacity is specified. Therefore, a length of the entire heat pipe can be shortened, a mounting design of the heat pipe can be facilitated, and difficulty in designing internal space of the heat dissipation device can be reduced.

[0025] Herein, in a length direction of the heat pipe, cross-sectional areas of all positions of the heat exchange cavity (the main pipe section) may be the same or different, cross-sectional areas of all positions of the first additional cavity (the first additional pipe section) may be the same or different, and that the cross-sectional area of the first additional cavity is greater than the cross-sectional area of the heat exchange cavity means that cross-sectional areas of at least some positions of the first additional cavity are greater than a maximum cross-sectional area of the heat exchange cavity.

[0026] In this embodiment of this application, the cross-sectional areas of the all positions of the heat exchange cavity (the main pipe section) are the same, and the cross-sectional areas of the all positions of the first additional cavity (the first additional pipe section) are not exactly the same. In this case, the cross-sectional areas of the at least some positions (for example, a middle position) of the first additional cavity should be greater than the cross-sectional area of the heat exchange cavity.

[0027] Optionally, the cross-sectional areas of the all positions of the first additional cavity (the first additional pipe section) are the same, and the cross-sectional areas of the all positions of the heat exchange cavity (the main pipe section) are not exactly the same. In this case, the cross-sectional area of the first additional cavity should be greater than the maximum cross-sectional area of the heat exchange cavity.

[0028] Optionally, the cross-sectional areas of the all positions of the first additional cavity (the first additional pipe section) are not exactly the same, and the cross-sectional areas of the all positions of the heat exchange cavity (the main pipe section) are not exactly the same either. In this case, a maximum cross-sectional area of the first additional cavity should be greater than the maximum cross-sectional area of the heat exchange cavity.

[0029] In a possible design, the first additional pipe section is bent towards one side relative to the evaporation section, so that an included angle is formed between the first additional pipe section and the evaporation section.

[0030] Herein, that the included angle is formed between the first additional pipe section and the evaporation section means that extension directions of the first additional pipe section and the evaporation section are different, bending occurs between the first additional pipe section and the evaporation section to form an included angle greater than 0 degrees, and the first additional pipe section is bent relative to the evaporation section to form the included angle, where the included angle may be, for example, 90 degrees to 135 degrees, for example, 100 degrees, 105 degrees, 110 degrees, 120 degrees, or 125 degrees.

[0031] According to the disposing, it can be convenient for the evaporation section to connect to a heat source or a heat sink, and the condensation section to connect to a heat sink. In addition, this helps ensure that the first additional pipe section can stay away from the heat source or the heat sink in space, so that the first additional pipe section can be away from and not in contact with the heat source or the heat sink. In this case, even if the first additional pipe section deforms to some extent due to the icing expansion of the heat exchange medium, heat dissipation performance of the heat dissipation device is not adversely affected. Therefore, the heat pipe provided in this embodiment of this application has high use stability, and can meet a use requirement of the heat dissipation device in a low-temperature condition.

[0032] Optionally, the two additional pipe sections (namely, the first additional pipe section and the second additional pipe section) are bent towards a same side relative to the main pipe section, and bending angles are the same. In this case, the second additional pipe section may be bent to one side relative to the condensation section, so that an included angle is also formed between the second additional pipe section and the condensation section, and both a bending direction and the included angle of the second additional pipe section are the same as those of the first additional pipe section.

[0033] Optionally, to conveniently stay away from the heat source or the heat sink, the two additional pipe sections may alternatively be bent towards different sides relative to the main pipe section, and the bending angles of the two additional pipe sections may alternatively be different.

[0034] In a possible design, the capillary structure extends into the first additional cavity.

[0035] In this case, after the capillary structure penetrates the entire main pipe section, two ends extend into the additional cavities on corresponding sides respectively, that is, one end extends into the first additional cavity, and the other end extends into the second additional cavity. According to the disposing, the heat transfer medium condensed into a liquid state in the first additional cavity can quickly flow back to the evaporation section by using the capillary structure, thereby improving heat transfer performance of the heat pipe.

[0036] In a possible design, the first additional pipe section includes an end pipe section and a transition pipe section, the end pipe section is connected to the evaporation section through the transition pipe section, the evaporation section is a flat pipe, and the end pipe section is a circular pipe.

[0037] The evaporation section is disposed as the flat pipe, so that an area of attachment between the evaporation section and a heat source or a heat sink can be increased, which is conducive to strengthening heat transfer. The circular pipe has strong mechanical strength, and the end pipe section mainly used to accommodate the heat transfer medium is disposed as the circular pipe, so that the first additional pipe section is not prone to deformation. This further helps improve structural stability of the entire heat pipe. In a possible design, the heat insulation section is a bent pipe section capable of elastic deformation.

[0038] The heat insulation section does not need to be attached to a heat exchanger or a heat source, and the heat insulation section is disposed as the bent pipe section, which does not greatly affect a heat transfer capability of the heat pipe. In this case, the heat insulation section may be deformed (for example, bent) to extend or reduce an overall length of the pipe body, and the evaporation section and the condensation section can further float relatively to change a height difference between the evaporation section and the condensation section, so that an adaptation capability of the heat pipe can be improved, universality of the heat pipe can be improved, and the heat pipe can be applied to more scenarios.

[0039] Optionally, the heat insulation section may be any pipe section having a curved section or a bent section, for example, an arch-shaped section, an arc-shaped section, an S-shaped section, a wavy section, a spiral section, or a W-shaped section.

[0040] In a possible design, the capillary structure is a wick, and the wick is attached to an inner wall of the pipe body.

[0041] Optionally, the wick may be formed on the inner wall of the pipe body by using metal powder (for example, copper powder) and through sintering by using a powder metallurgy process. In addition, the wick may alternatively be an artificial fiber.

[0042] According to a second aspect, this application further provides a heat dissipation module, including a first heat sink; a second heat sink; and the heat pipe according to any possible design of this first aspect, where the evaporation section is connected to the first heat sink, the condensation section is connected to the second heat sink, and the first additional pipe section is spaced apart from and is not in contact with the first heat sink and the second heat sink.

[0043] The first additional pipe section of the heat pipe is spaced apart from and is not in contact with the first heat sink and the second heat sink, that is, the first additional pipe section is away from the first heat sink and the second heat sink in space. In this case, even if the first additional pipe section deforms to some extent due to icing expansion of the heat exchange medium, a connection between the heat pipe and the heat sink is not affected, for example, no gap is generated at joints between the evaporation section and the first heat sink and between the condensation section and the second heat sink, that is, no adverse impact is imposed on heat dissipation performance of the entire heat dissipation module. Therefore, the heat dissipation module provided in this embodiment of this application has high use stability, and can meet a use requirement of the heat dissipation device at a low temperature.

[0044] Optionally, the first heat sink and the second heat sink may be metal heat sinks. For example, the metal may be an aluminum alloy, a copper alloy, stainless steel, or the like. However, this is not limited thereto.

[0045] In a possible design, the first heat sink includes a first substrate and a first fin disposed on the first substrate, and the evaporation section is attached to the first substrate; and the second heat sink includes a second substrate and a second fin disposed on the second substrate, and the condensation section is attached to the second substrate.

[0046] According to a third aspect, this application further provides a heat dissipation device, including a circuit board, where a heat emitting component is disposed on the circuit board; and the heat dissipation module according to any possible design of this second aspect, where the heat dissipation module is configured to dissipate heat for the heat emitting component.

[0047] Optionally, the heat dissipation device may be an electronic device. The electronic device may be, for example, a network device like a router, a server, a switch, or a communication base station, or may be a terminal device like a mobile phone, a notebook computer, a desktop computer, or a vehicle-mounted device. In a possible implementation, the electronic device may alternatively be a vehicle (for example, an electric vehicle), that is, heat may be dissipated for a heat emitting component on the vehicle by using the heat dissipation module.

[0048] Optionally, the circuit board may be a printed circuit board (printed circuit board, PCB).

[0049] Optionally, the heat emitting component may be any electrical element that can be disposed on the circuit board and on which heat dissipation needs to be performed, for example, various processing chips or circuits. For example, the heat emitting component may be a network processor, and in this case, the heat dissipation device may be a router. For another example, the heat emitting component may alternatively be a central processing unit (central processing unit, CPU), a graphics processing unit (graphics processing unit, GPU) or a graphics card, a memory module (memory chip), or the like. In this case, the heat dissipation device may be a server.

[0050] In a possible design, there are a plurality of heat emitting components, the first heat sink is connected to some of the heat emitting components, and the second heat sink is connected to the other heat emitting components.

[0051] In a possible design, the heat dissipation device further includes a heat dissipation fan configured to dissipate heat for the heat dissipation module.

[0052] Optionally, the heat dissipation fan may be an axial fan, a cross-flow fan, or a centrifugal fan.

[0053] In a possible design, there are a plurality of heat dissipation modules, and are configured to dissipate heat for the plurality of heat emitting components.

[0054] According to a fourth aspect, this application further provides a heat dissipation device, including a heat emitting component; the heat pipe according to any possible design of the first aspect, where the evaporation section is connected to the heat emitting component, and the first additional pipe section is not in contact with the heat emitting component; and a heat dissipation component, configured to dissipate heat for the condensation section.

[0055] Optionally, the heat emitting component herein may be various components (namely, heat sources, for example, various chips or circuits) that can emit heat, or may be an indirect heat transfer component (for example, a heat sink) configured to transfer heat of the heat source.

[0056] Optionally, the heat dissipation component herein is configured to dissipate heat on the condensation section. For example, the heat dissipation component may be a heat sink, a heat dissipation fin, or a heat dissipation fan.

[0057] Because the heat dissipation device uses the heat pipe according to any possible design of the first aspect, the heat dissipation device also has technical effect corresponding to that of the heat pipe. Details are not described herein again.

BRIEF DESCRIPTION OF DRAWINGS

[0058] 

FIG. 1 is a diagram of an overall structure of an example of a heat pipe according to an embodiment of this application;

FIG. 2 is a front view of the heat pipe shown in FIG. 1;

FIG. 3 is sectional views of the heat pipe shown in FIG. 2 from various perspectives;

FIG. 4 is an overall sectional view of the heat pipe shown in FIG. 1;

FIG. 5 is sectional views of an end pipe section in various implementations;

FIG. 6 is a diagram of an overall structure of another example of a heat pipe according to an embodiment of this application;

FIG. 7 is a diagram of an overall structure of an example of a heat dissipation module according to an embodiment of this application;

FIG. 8 is a diagram of an overall structure of another example of a heat dissipation module according to an embodiment of this application;

FIG. 9 is a diagram of an overall structure of an example of a heat dissipation device according to an embodiment of this application;

FIG. 10 is a diagram of assembly of a heat dissipation module and a circuit board inside the heat dissipation device shown in FIG. 9;

FIG. 11 is a diagram of a connection between a circuit board and a heat emitting component;

FIG. 12 is a diagram of another example of assembly of a heat dissipation module and a circuit board; and

FIG. 13 is a diagram of still another example of assembly of a heat dissipation module and a circuit board.

Reference numerals:

[0059] 

1: pipe body; 2: sealed cavity; 2a: first additional cavity; 2b: heat exchange cavity; 2c: second additional cavity; 3: capillary structure; 4: heat transfer medium; a: end pipe section; b: transition pipe section;

10: heat pipe; 11: evaporation section; 12: heat insulation section; 121: first bent section; 122: second bent section; 123: third bent section; 13: condensation section; 14: first additional pipe section; 15: second additional pipe section;

20: first heat sink; 21: first substrate; 22: first fin;

30: second heat sink; 31: second substrate; 32: second fin;

40: connecting plate;

100: heat dissipation module;

200: housing; 210: air intake vent;

300: circuit board;

400: heat emitting component;

500: heat dissipation fan; and

1000: heat dissipation device.

DESCRIPTION OF EMBODIMENTS

[0060] The following describes implementations of this application in detail. Examples of the implementations are shown in accompanying drawings. Same or similar reference signs are always used to indicate same or similar elements or elements having same or similar functions. The implementations described below with reference to the accompanying drawings are examples, and are merely used to explain this application, but cannot be understood as a limitation on this application.

[0061] It should be understood that, terms "first" and "second" in descriptions of this application are merely used for a purpose of description, and shall not be understood as an indication or implication of relative importance or implicit indication of a quantity of indicated technical features. Therefore, a feature limited by "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise specifically limited.

[0062] In the description of this application, it should be noted that, unless otherwise specified and limited, terms "mounting", and "connection" should be understood in a broad sense. For example, a connection may be a fastened connection, a detachable connection, or an integrated connection. Alternatively, a connection may be a mechanical connection or an electrical connection, or may mean mutual communication. Alternatively, a connection may be a direct connection, or an indirect connection through an intermediate medium, or may be a connection between two elements or an interaction relationship between two elements. For a person of ordinary skill in the art, specific meanings of the foregoing terms in this application may be understood based on a specific situation.

[0063] In the description of this application, it should be understood that orientation or position relationships indicated by terms such as "upper", "lower", "side", "front", and "rear" are based on orientation or position relationships of mounting, and are used only for ease and brevity of illustration and description of this application, rather than indicating or implying that the mentioned apparatus or element needs to have a particular orientation or needs to be constructed and operated in a particular orientation. Therefore, such terms should not be understood as a limitation on this application.

[0064] It should be further noted that in embodiments of this application, a same reference numeral indicates a same component or a same part. For same parts in embodiments of this application, only one part or component marked with a reference numeral may be used as an example in the figure. It should be understood that the reference numeral is also applicable to another same part or component.

[0065] Due to features such as a small size, high heat transfer efficiency, a simple structure, a light weight, no additional force, a long service life, low heat resistance, and long-distance transmission, a heat pipe (heat pipe, HP) meets use requirements of heat dissipation modules of various electronic devices such as a router and a server, and is therefore widely used to resolve a heat dissipation problem. A basic structure of the heat pipe is that a capillary structure layer that easily absorbs working liquid is disposed on an inner wall of a sealed pipe, central space of the sealed pipe is in a void state, and the working liquid is injected into the sealed pipe that is vacuumized, to implement heat transfer through a cyclic phase change of the working liquid. As a two-phase heat transfer device, an effective thermal conductivity of the heat pipe is dozens of times that of metal (for example, pure copper).

[0066] A position of the heat pipe can be divided into three sections: an evaporation section, a heat insulation section (also referred to as a connection section or a transition section), and a condensation section based on a function of heat absorption or heat release. A working principle of the heat pipe is as follows: The liquid working medium in the capillary structure of the evaporation section absorbs heat from an external heat source and is evaporated into vapor. Due to a pressure difference generated by the vapor, the vapor quickly passes through the heat insulation section and moves to the condensation section. The vapor releases heat in the condensation section and is cooled to condense into liquid. In this case, the condensed working fluid is absorbed in the capillary structure of the condensation section, and flows back to the evaporation section under the action of capillary force of the capillary structure. Movement and regression processes of the working fluid operate cyclically, so that the evaporation section continuously transmits heat to the condensation section through the heat insulation section.

[0067] As power consumption of chips and boards of network devices such as a router, a server, and a switch increases, space of boards and cabinets cannot increase proportionally. As a result, power density keeps increasing, and heat dissipation requirements become increasingly high. In addition, layout of a plurality of chips on the board requires heat dissipation at a uniform temperature, to avoid chip overheating caused by a poor local heat dissipation condition. To effectively resolve the foregoing heat dissipation problem, in the conventional technology, a heat pipe is usually combined with a heat sink to form a heat dissipation module, and heat is dissipated for a heat emitting element in a heat dissipation device by using the heat dissipation module.

[0068] In actual application, the heat dissipation module usually includes two heat sinks and at least one heat pipe. An evaporation section of the heat pipe is connected to one of the heat sinks, and a condensation section of the heat pipe is connected to the other heat sink. During use, the two heat sinks are attached to two heat emitting elements (for example, chips) on a board respectively, so that heat can be dissipated for the two heat emitting elements at the same time. Because the heat pipe is used as a heat bridge to connect the two heat sinks, the two heat sinks can promote the heat dissipation of each other, and utilization of heat dissipation fins on the heat sinks is high, so that overall heat dissipation efficiency of the electronic device can be improved, and a problem of local overheating caused by a poor local heat dissipation condition can be effectively avoided.

[0069] The heat pipe may be in a low-temperature environment (for example, outdoors) in a process of using, storing, assembling, or transporting the heat pipe. In this case, the working substance (for example, water) inside the heat pipe may ice. When mechanical strength of the heat pipe is insufficient to resist expansion force generated due to an increase in volume caused by freezing of the working substance, the heat pipe expands and deforms, which reduces performance of the entire heat dissipation module or even the heat dissipation module fails.

[0070] Specifically, when the heat pipe is used in the electronic device in a vertically placed manner, or is stored or transported in a vertically placed manner, the capillary force of the capillary structure (for example, a wick) of the heat pipe may be insufficient to keep all the working substance in pores of the capillary structure, a part of the working substance gathers at the bottom of a lower end of the heat pipe due to gravity. In this case, if an ambient temperature is low (for example, far lower than 0°C), the working substance inside the heat pipe ices and expands, and the bottom of the heat pipe expands and deforms. In this case, the contact between the heat pipe and the heat sink may be affected, an air gap is easily generated at a joint between the heat pipe and the heat sink and heat transfer resistance is increased, and the heat pipe is even separated from the heat sink. As a result, heat dissipation performance of the entire heat dissipation device deteriorates or even the heat dissipation device fails.

[0071] In conclusion, embodiments of this application provide a heat pipe for preventing icing expansion, a heat dissipation module, and a heat dissipation device. A first additional pipe section is disposed at an end of the heat pipe. The first additional pipe section has a first additional cavity therein configured to accommodate a heat transfer medium and allow the heat transfer medium to ice and expand. During use after mounting, the first additional pipe section is not in contact with a heat emitting component of the heat dissipation device. In this case, even if the first additional pipe section expands and deforms due to freezing of the internal heat transfer medium, stability of contact between the heat pipe and the heat dissipation component is not affected, thereby ensuring reliable heat dissipation performance of the heat pipe.

[0072] An embodiment of this application first provides a heat pipe 10 for preventing icing expansion. The heat pipe 10 can be combined with a heat sink to form a heat dissipation module. The heat dissipation module can be configured to dissipate heat for a heat dissipation device. The heat dissipation device may be, for example, an electronic device like a router or a server. FIG. 1 is a diagram of an overall structure of an example of the heat pipe 10 according to an embodiment of this application. FIG. 2 is a front view of the heat pipe 10 shown in FIG. 1. FIG. 3 is sectional views of the heat pipe 10 shown in FIG. 2 from various perspectives, and FIG. 4 is an overall sectional view of the heat pipe 10 shown in FIG. 1. A part (a) to a part (e) in FIG. 3 are the sectional views of the heat pipe 10 shown in FIG. 2 from perspectives of AA, BB, CC, DD, and EE respectively.

[0073] As shown in FIG. 1 to FIG. 4, the heat pipe 10 provided in this embodiment of this application includes a pipe body 1 having a sealed cavity 2, an inner wall surface of the pipe body 1 is smooth or provided with a micro groove, a capillary structure 3 is disposed in the sealed cavity 2, and space other than the capillary structure 3 in the sealed cavity 2 is used as a vapor channel. An appropriate amount of heat transfer medium 4 is further sealed in the sealed cavity 2 and the sealed cavity 2 can be vacuumized.

[0074] The pipe body 1 includes a main pipe section and a first additional pipe section 14. The main pipe section is sequentially divided into an evaporation section 11, a heat insulation section 12, and a condensation section 13 in a length direction of the pipe body 1 based on a use function of each section. The capillary structure 3 is disposed at least in the length direction of the pipe body 1 and extends from the evaporation section 11 to the condensation section 13, that is, the capillary structure 3 is located at least in the main pipe section. Usually, the capillary structure 3 may also be disposed in the first additional pipe section 14, or the capillary structure may not be disposed. In this application, the sections (11, 12, and 13) are obtained through division based on functions of the sections during normal working. To be specific, during the normal working, a temperature of a component in contact with the evaporation section 11 is usually greater than a temperature of a component in contact with the condensation section 13. Therefore, the heat transfer medium 4 is evaporated in the evaporation section 11, and moves to the condensation section 13 for cooling. However, in actual application, the temperature of the component in contact with the evaporation section 11 may be lower than the temperature of the component in contact with the condensation section 13. Because internal structures of the sections are similar (all include the capillary structure), the condensation section 13 becomes an "evaporation section" having an evaporation function, and the evaporation section 11 becomes a "condensation section" having a condensation function.

[0075] The evaporation section 11 is configured to connect to a heat source to absorb heat of the heat source, the heat transfer medium 4 in a liquid state is evaporated into a vapor state because of being heated, and due to a pressure difference generated by the vapor, the vapor can quickly pass through the heat insulation section 12 and move to the condensation section 13. The condensation section 13 is configured to dissipate the heat brought by the heat transfer medium 4, and condense the heat transfer medium 4 in the vapor state into a liquid state, and the heat transfer medium 4 in the liquid state returns to the evaporation section 11 again under the action of the capillary structure 3, so that the evaporation section 11 can continuously transfer the heat to the condensation section 13 through the heat insulation section 12.

[0076] Optionally, in some cases, the evaporation section 11 and the condensation section 13 of the heat pipe 10 provided in this embodiment of this application may be exchanged for use. To be specific, the condensation section 13 may be connected to the heat source, and the heat is dissipated to the outside of the pipe body through the evaporation section 11. In this case, structures of the evaporation section 11 and the condensation section 13 may be exactly the same. An advantage of the disposing is that the evaporation section 11 and the condensation section 13 do not need to be discriminated, so that adaptability of the heat pipe 10 can be improved, and mounting efficiency of the heat pipe 10 can be improved.

[0077] The pipe body 1 is made of a material with a good heat-conducting property, for example, may be made of a copper material, or may be made of another material, for example, aluminum, steel, carbon steel, stainless steel, iron, nickel, titanium and alloys thereof, or a polymer material with a good heat-conducting property, based on a different requirement. However, this is not limited thereto.

[0078] The pipe body 1 may be of an integrated structure made by using an integrated molding process, or may be formed by sequentially splicing (for example, welding) a plurality of pipe sections. The plurality of pipe sections may be made of a same material or different materials. For example, both the evaporation section 11 and the condensation section 13 may be made of a metal material, and the heat insulation section 12 may be made of a non-metal material. For example, the heat insulation section 12 may be made of at least one of polymer materials such as plastic, resin, rubber, and synthetic fiber. In this case, material costs of the heat pipe 10 can be saved, a weight of the heat pipe 10 can be light, and the heat insulation section 12 can have good heat insulation performance.

[0079] In a possible implementation, the heat pipe 10 is further flexible and bendable. In this case, the heat pipe 10 may be used in a foldable electronic device (for example, a mobile phone or a tablet computer). In this case, the heat insulation section 12 may be made of a material like flexible graphite, flexible rubber, or flexible resin. For example, the heat insulation section 12 may be made of a flexible polymer material like polyimide (polyimide, PI), polyethylene terephthalate, or polyethylene naphthalate.

[0080] Optionally, the capillary structure 3 may be of any type like a groove type, a sintered powder type, a fiber type, a grid type, or a honeycomb type. However, this is not limited thereto. As shown in FIG. 3 and FIG. 4, in this embodiment of this application, the capillary structure 3 is a wick, the wick is attached to the inner wall of the pipe body 1, and an internal void cavity of the wick forms the vapor channel for vapor circulation. The wick may be formed on the inner wall of the pipe body 1 by using metal powder (for example, copper powder) and through sintering by using a powder metallurgy process. In addition, the wick may alternatively be an artificial fiber.

[0081] Optionally, the heat transfer medium 4 may be one or a mixture of water, methanol, ethanol, acetone, liquid ammonia, heptane, or the like.

[0082] As shown in FIG. 1 to FIG. 4, in this embodiment of this application, the heat pipe 10 further includes the first additional pipe section 14. An outer end part of the first additional pipe section 14 is sealed and disposed as an end of the pipe body 1, that is, the first additional pipe section 14 is connected to an end part of the main pipe section, and a first additional cavity 2a is disposed in the additional pipe section 14. As a part of the sealed cavity 2, the first additional cavity 2a is connected to a heat exchange cavity 2b located in the main pipe section, and the first additional cavity 2a is configured to accommodate the heat transfer medium and allow the heat transfer medium to ice and expand. The first additional pipe section 14 and the main pipe section may form the pipe body 1 by using the integrated molding process, or may be used as two separate pipe sections that are interconnected (for example, sealed welding) to form the pipe body 1. This is not limited in this application.

[0083] The first additional cavity 2a is used to accommodate all or a part of the heat transfer medium 4 when the heat pipe 10 is vertically placed and the first additional pipe section 14 is located below a gravity direction. When the heat pipe 10 is mounted on a heat dissipation device that requires heat dissipation, the first additional pipe section 14 is not in contact with a heat emitting component of the heat dissipation device.

[0084] The heat pipe 10 provided in this embodiment of this application includes the main pipe section and the first additional pipe section 14. The first additional pipe section 14 is disposed at an end of the main pipe section, which means to add the first additional pipe section 14 to the conventional heat pipe. When the heat pipe 10 is used after being mounted, the evaporation section 11 in the main pipe section is in contact with the heat emitting component like a heat source or a heat sink in the heat dissipation device to perform heat transfer, and the first additional pipe section 14 is not used as the evaporation section or the condensation section, that is, the first additional pipe section 14 is not in contact with (for example, attached to) the heat emitting component.

[0085] As shown in FIG. 4, the first additional pipe section 14 is disposed at an end part of the evaporation section 11, that is, the first additional pipe section 14 is connected to the end part of the evaporation section 11. It can be understood that the evaporation section 11 has two end parts, one end part is connected to the heat insulation section 12, and the other end part is connected to the first additional pipe section 14. The first additional pipe section 14 has the first additional cavity 2a therein, so that when the heat pipe 10 is vertically placed and the first additional pipe section 14 is placed at the bottom, the part of the heat transfer medium 4 is separated from the capillary structure 3 due to gravity and gathers in the first additional cavity 2a. The first additional cavity 2a has a sufficient volume to accommodate the heat transfer medium 4 and allow the heat transfer medium 4 to ice and expand.

[0086] In this case, even if the first additional pipe section 14 deforms to some extent due to the icing expansion, because the first additional pipe section 14 is not in contact with a heat dissipation component, stability of contact between the evaporation section 11 and the heat emitting component is not affected, so that the evaporation section 11 can always be stably and reliably connected to the heat emitting component, no air gap is generated at a joint between the evaporation section 11 and the heat emitting component, and heat dissipation performance of the heat pipe 10 is not adversely affected. This ensures that the heat pipe 10 provided in this embodiment of this application has stable and reliable heat dissipation performance. Therefore, it is also convenient to perform operations such as usage, storage, assembly, and transportation on the heat pipe 10. In this case, the heat pipe 10 can be vertically placed in a transportation process, and the first additional pipe section 14 is disposed at the bottom.

[0087] Optionally, the heat dissipation device herein may be various devices that require heat dissipation, for example, may be an electronic device. The electronic device may be a network device like a router, a server, a switch, or a communication base station, or may be a terminal device like a mobile phone, a notebook computer, a desktop computer, or a vehicle-mounted device.

[0088] In a possible implementation, the heat dissipation device may alternatively be a vehicle (for example, an electric vehicle), that is, heat is dissipated for a heat emitting component on the vehicle by using the heat pipe.

[0089] Optionally, the heat emitting component herein may be various components (namely, heat sources, for example, various chips or circuits) that can emit heat and that are inside the heat dissipation device, or may be an indirect (intermediate) heat transfer component (for example, a heat sink) configured to transfer heat of the heat source.

[0090] As shown in FIG. 4, in this embodiment of this application, when the heat pipe 10 is vertically placed and the first additional pipe section 14 is located below the gravity direction, the first additional cavity 2a can accommodate all heat transfer medium 4 that cannot be maintained inside the capillary structure 3.

[0091] In other words, the first additional cavity 2a has the sufficient volume to accommodate the heat transfer medium 4, to ensure that the heat transfer medium 4 does not overflow into the evaporation section 11 when the heat pipe 10 is vertically placed, thereby avoiding deformation of the evaporation section 11 due to the icing expansion of the working substance. This ensures that the evaporation section 11 can always be stably and reliably connected to the heat emitting component, and ensures that the heat pipe 10 has the stable and reliable heat dissipation performance.

[0092] As shown in FIG. 1 to FIG. 4, the pipe body 1 provided in this embodiment of this application further includes a second additional pipe section 15, and the second additional pipe section 15 is connected to an end part of the condensation section 13. It can be understood that the condensation section 13 has two end parts, one end part is connected to the heat insulation section 12, and the other end part is connected to the second additional pipe section 15. A second additional cavity 2c is disposed in the second additional pipe section 15, and the second additional cavity 2c is used to accommodate the all or the part of the heat transfer medium 4 when the heat pipe 10 is vertically placed and the second additional pipe section 15 is located below the gravity direction.

[0093] In other words, each of two end parts of the main pipe section is connected to an additional pipe section, that is, the first additional pipe section 14 is connected to the evaporation section 11, the second additional pipe section 15 is connected to the condensation section 13, and the sealed cavity 2 includes the first additional cavity 2a, the second additional cavity 2c, and the heat exchange cavity 2b. An advantage of the disposing is that, in this case, any end part of the heat pipe 10 has the additional cavity that allows the icing expansion of the heat transfer medium 4, and the heat pipe 10 has strong adaptability. When the heat pipe 10 is vertically placed for use, transportation, or storage, an operator may dispose any end part of the heat pipe 10 at the bottom without selection, so that a step of discrimination is omitted, thereby improving operation efficiency.

[0094] Optionally, in another implementation, the heat pipe 10 may include only one additional pipe section. In this case, the only additional pipe section may be disposed at any end part of the main pipe section. For example, the additional pipe section may be connected to the evaporation section 11, or connected to the condensation section 13, and the other end part of the main pipe section that is not provided with the additional pipe section is sealed.

[0095] As shown in FIG. 1 to FIG. 3, the first additional pipe section 14 is bent towards one side relative to the evaporation section 11, so that an included angle is formed between the first additional pipe section 14 and the evaporation section 11. Herein, that the included angle is formed between the additional pipe section 14 and the evaporation section 11 means that extension directions of the additional pipe section 14 and the evaporation section 11 are different, bending occurs between the additional pipe section 14 and the evaporation section 11 to form an included angle greater than 0 degrees, and the first additional pipe section 14 is bent relative to the evaporation section 11 to form the included angle, where the included angle may be, for example, 90 degrees to 135 degrees, for example, 100 degrees, 105 degrees, 110 degrees, 120 degrees, or 125 degrees. According to the disposing, it can be convenient for the evaporation section 11 to connect to a heat source or a heat sink, and the condensation section 13 to connect to a heat sink. In addition, this helps ensure that the first additional pipe section 14 can stay away from the heat source or the heat sink in space, so that the first additional pipe section 14 can be away from and not in contact with the heat source or the heat sink. In this case, even if the first additional pipe section 14 deforms to some extent due to the icing expansion of the heat transfer medium 4, the heat dissipation performance of the heat pipe 10 is not adversely affected. Therefore, the heat pipe 10 provided in this embodiment of this application has high use stability.

[0096] As shown in FIG. 1 to FIG. 3, in this embodiment of this application, the two additional pipe sections (namely, the first additional pipe section 14 and the second additional pipe section 15) are bent towards a same side relative to the main pipe section, and bending angles are the same. In this case, the second additional pipe section 15 may be bent to one side relative to the condensation section 13, so that an included angle is also formed between the second additional pipe section 15 and the condensation section 13, and both a bending direction and the included angle of the second additional pipe section 15 are the same as those of the first additional pipe section 14.

[0097] In another implementation, to conveniently stay away from the heat source or the heat sink, the two additional pipe sections may alternatively be bent towards different sides relative to the main pipe section, and the bending angles of the two additional pipe sections may alternatively be different. This is not specifically limited in this application.

[0098] When the evaporation section 11 is connected to the heat emitting component like the heat source, the evaporation section 11 absorbs the heat of the heat source, and the heat transfer medium 4 in the liquid state is evaporated into the vapor state because of being heated, and due to the pressure difference generated by the vapor, the vapor can not only flows into the condensation section 13, but also flow into the first additional pipe section 14 (namely, the first additional cavity 2a). In this case, the first additional pipe section 14 also has a specific condensation function. In this embodiment of this application, as shown in the part (a) in FIG. 3, the part (e) in FIG. 3, and FIG. 4, the capillary structure 3 extends to the first additional cavity 2a. In this case, after the capillary structure 3 penetrates the entire main pipe section, two ends extend into the additional cavities on corresponding sides respectively, that is, one end extends into the first additional cavity 2a, and the other end extends into the second additional cavity 2c. According to the disposing, the heat transfer medium 4 condensed into the liquid state in the first additional cavity 2a can quickly flow back to the evaporation section 11 by using the capillary structure 3, thereby improving heat transfer performance of the heat pipe 10.

[0099] As shown in FIG. 1 to FIG. 4, in this embodiment of this application, the main pipe section and the first additional pipe section 14 have different cross-sectional shapes. The main pipe section is a flat pipe. The first additional pipe section 14 includes an end pipe section a and a transition pipe section b, the end pipe section a is connected to the evaporation section 11 through the transition pipe section b, the end pipe section a is located at an end of the heat pipe 10, the first additional cavity 2a is mainly formed inside the end pipe section a, and the end pipe section a is a circular pipe. The main pipe section is disposed as the flat pipe, so that areas of attachment between the evaporation section 11 and the heat source or the heat sink and between the condensation section 13 and the heat source or the heat sink can be increased, which is conducive to strengthening heat transfer. The circular pipe has strong mechanical strength, and the end pipe section a mainly used to accommodate the heat transfer medium 4 is disposed as the circular pipe, so that the first additional pipe section 14 is not prone to deformation. This further helps improve structural stability of the entire heat pipe 10.

[0100] As shown in FIG. 1, FIG. 2, the part (b) in FIG. 3, the part (c) in FIG. 3, the part (d) in FIG. 3, and FIG. 4, the main pipe section is the flat pipe, the cross-sectional shape is a rectangle, and two adjacent sides of the rectangle can be connected by rounded corners. Cross-sectional shapes and sizes of parts of the evaporation section 11, the heat insulation section 12, and the condensation section 13 are the same, so that processing can be convenient.

[0101] Optionally, in another implementation, shapes and sizes of the sections of the main pipe section may also be different. For example, both the evaporation section 11 and the condensation section 13 may be flat pipes to increase the areas of attachment to the heat source or the heat exchanger, but the heat insulation section 12 may be disposed as a circular pipe.

[0102] As shown in FIG. 1, FIG. 2, the part (a) in FIG. 3, the part (e) in FIG. 3, and FIG. 4, both the first additional pipe section 14 and the second additional pipe section 15 include the end pipe section a and the transition pipe section b, a cross-sectional shape of the end pipe section a is a circle, and the circle includes, but is not limited to, a related shape like a standard circle, an ellipse, or an approximate circle.

[0103] Further, as shown in FIG. 1 to FIG. 4, the cross-sectional shape of the end pipe section a is the circle, and in a direction of a center line (axial direction) of the pipe section, cross-sectional areas of all parts may be the same or may be different. For example, the cross-sectional areas of the all parts in the direction of the center line of the end pipe section a are the same, and in this case, the end pipe section a is in a cylindrical shape. For another example, the cross-sectional areas of the all parts in the direction of the center line of the end pipe section a are different, and in this case, the end pipe section a may be in a conical shape as a whole, and a middle part may be in a frustum shape, or a combination of a conical shape and a cylindrical shape.

[0104] As shown in FIG. 1 to FIG. 4, in this embodiment of this application, both the first additional pipe section 14 and the second additional pipe section 15 include the end pipe section a and the transition pipe section b that are connected to each other, and each transition pipe section b is connected to the evaporation section 11 or the condensation section 13. In other words, the end pipe section a is connected to the evaporation section 11 or the condensation section 13 through the transition pipe section b. The transition pipe section b is configured to make transition from the flat pipe of the main pipe section to the circular pipe of the end pipe section a, while the end pipe section a of the first additional pipe section 14 and the second additional pipe section 15 each include a cylindrical section disposed adjacent to the main pipe section and a conical section located at the end. Disposing of the conical section helps reduce an area of the end of the additional pipe section, and makes it convenient to seal the additional pipe section.

[0105] FIG. 5 is sectional views of the end pipe section a in various other implementations. As shown in a part (a) in FIG. 5, the cross-sectional shape of the end pipe section a may alternatively be the ellipse. As shown in a part (b) in FIG. 5, the cross-sectional shape of the end pipe section a may alternatively be an irregular circle with a straight side. In the description of this application, that the end pipe section a is the circular pipe should include at least three cases: the part (a) in FIG. 3, the part (a) in FIG. 5, and the part (b) in FIG. 5.

[0106] As shown in a part (c) in FIG. 5, the cross-sectional shape of the end pipe section a may alternatively be a polygon whose sides are approximately equal, for example, a rectangle (square), a regular pentagon, or a regular hexagon, and the cross-sectional shape can also ensure that the first additional pipe section 14 has high mechanical strength.

[0107] Structural parameters such as a shape, a size, and the bending angle of the first additional pipe section 14 depend on factors such as a design of the main pipe section, for example, a length, a total thickness, a wall thickness, and parameters (for example, a porosity of the wick, a pore size of the pore, and the capillary force) of the wick of the main pipe section, and a filling rate of the heat transfer medium.

[0108] As shown in FIG. 3 and FIG. 4, in this embodiment of this application, the sealed cavity 2 includes the heat exchange cavity 2b located in the main pipe section, and a cross-sectional area of the first additional cavity 2a is greater than a cross-sectional area of the heat exchange cavity 2b. Because the first additional cavity 2a has a larger cross-sectional area, the first additional pipe section 14 can be disposed shorter on the premise that a capacity is specified. Therefore, a length of the entire heat pipe 10 can be shortened, a mounting design of the heat pipe 10 can be facilitated, and difficulty in designing internal space of the heat dissipation device can be reduced.

[0109] Herein, in a length direction of the heat pipe 10, cross-sectional areas of all positions of the heat exchange cavity 2b (the main pipe section) may be the same or different, cross-sectional areas of all positions of the first additional cavity 2a (the first additional pipe section 14) may be the same or different, and that the cross-sectional area of the first additional cavity 2a is greater than the cross-sectional area of the heat exchange cavity 2b means that cross-sectional areas of at least some positions of the first additional cavity 2a are greater than a maximum cross-sectional area of the heat exchange cavity 2b.

[0110] In this embodiment of this application, the cross-sectional areas of the all positions of the heat exchange cavity 2b (the main pipe section) are the same, and the cross-sectional areas of the all positions of the first additional cavity 2a (the first additional pipe section 14) are not exactly the same. In this case, the cross-sectional areas of the at least some positions (for example, a middle position) of the first additional cavity 2a should be greater than the cross-sectional area of the heat exchange cavity 2b.

[0111] In a possible implementation, the cross-sectional areas of the all positions of the first additional cavity 2a (the first additional pipe section 14) are the same, and the cross-sectional areas of the all positions of the heat exchange cavity 2b (the main pipe section) are not exactly the same either. In this case, the cross-sectional area of the first additional cavity 2a should be greater than the maximum cross-sectional area of the heat exchange cavity 2b.

[0112] In a possible implementation, the cross-sectional areas of the all positions of the first additional cavity 2a (the first additional pipe section 14) are not exactly the same, and the cross-sectional areas of the all positions of the heat exchange cavity 2b (the main pipe section) are not exactly the same. In this case, a maximum cross-sectional area of the first additional cavity 2a should be greater than the maximum cross-sectional area of the heat exchange cavity 2b.

[0113] It should be noted that the first additional pipe section 14 and the second additional pipe section 15 are disposed respectively at two end parts of the heat pipe 10 provided in this embodiment of this application. For the two additional pipe sections, parameters such as a size, the bending angle, and the cross-sectional area and a shape of the additional cavity may be the same or may be different. This is not specifically limited in this application.

[0114] As shown in FIG. 1 to FIG. 3, in this embodiment of this application, the heat insulation section 12 is a bent pipe section capable of elastic deformation. The heat insulation section 12 does not need to be attached to the heat exchanger or the heat source, and the heat insulation section 12 is disposed as the bent pipe section, which does not greatly affect a heat transfer capability of the heat pipe 10. In this case, the heat insulation section 12 may be deformed (for example, bent) to extend or reduce an overall length of the pipe body 1, and the evaporation section 11 and the condensation section 13 can further float relatively to change a height difference between the evaporation section 11 and the condensation section 13, so that an adaptation capability of the heat pipe 10 can be improved, universality of the heat pipe 10 can be improved, and the heat pipe 10 can be applied to more scenarios.

[0115] The heat insulation section 12 in this embodiment of this application is arch-shaped, and includes a first bent section 121, a second bent section 122, and a third bent section 123 that are sequentially connected. The first bent section 121 is connected to the evaporation section 11, and is bent upwards in FIG. 2 relative to the evaporation section 11. The second bent section 122 is disposed in parallel relative to the evaporation section 11. The third bent section 123 is bent upwards relative to the condensation section 13 and connected to the second bent section 122 and the condensation section 13.

[0116] Optionally, in another implementation, the heat insulation section 12 may alternatively be in another form. For example, the heat insulation section 12 may alternatively be an arc-shaped, S-shaped, wavy, spiral, or W-shaped pipe section having a curved section or a bent section.

[0117] FIG. 6 is a diagram of an overall structure of another example of the heat pipe 10 according to an embodiment of this application. As shown in FIG. 6, compared with the embodiments shown in FIG. 1 to FIG. 5, in this embodiment, the heat pipe 10 is linear as a whole, a main pipe section including a heat insulation section 12 is a straight pipe, and two additional pipe sections located at two ends of the main pipe section are not bent relative to the main pipe section. In other words, a first additional pipe section 14 or a second additional pipe section 15 may not be bent, and can also stay away from a heat emitting component in space without being in contact with the heat emitting component.

[0118] In addition, an embodiment of this application further provides a heat dissipation module 100. The heat dissipation module 100 can be used in various heat dissipation devices, for example, used in an electronic device like a router or a server, to dissipate heat for a heat emitting component (for example, a chip) inside the electronic device. FIG. 7 is a diagram of an overall structure of an example of the heat dissipation module 100 according to this embodiment of this application. As shown in FIG. 7, the heat dissipation module 100 provided in this embodiment of this application includes a first heat sink 20, a second heat sink 30, and the heat pipe 10 provided in any one of the foregoing embodiments. The heat pipe 10 is connected to the first heat sink 20 and the second heat sink 30. The evaporation section 11 of the heat pipe 10 is connected to the first heat sink 20, the condensation section 13 of the heat pipe 10 is connected to the second heat sink 30, and the heat pipe 10 may be used as a heat bridge to connect the first heat sink 20 and the second heat sink 30.

[0119] The first additional pipe section 14 of the heat pipe 10 is spaced apart from and is not in contact with the first heat sink 20 and the second heat sink 30, that is, the additional pipe section 14 is away from the first heat sink 20 and the second heat sink 30 in space. In this case, even if the first additional pipe section 14 deforms to some extent due to the icing expansion of the heat exchange medium, a connection between the heat pipe 10 and the heat sink is not affected, for example, no gap is generated at joints between the evaporation section 11 and the first heat sink 20 and between the condensation section 13 and the second heat sink 30, that is, no adverse impact is imposed on heat dissipation performance of the entire heat dissipation module 100. Therefore, the heat dissipation module 100 provided in this embodiment of this application has high use stability, and can meet a use requirement of the heat dissipation device at a low temperature.

[0120] Similarly, the second additional pipe section 15 of the heat pipe 10 is spaced apart from and is not in contact with the first heat sink 20 and the second heat sink 30, that is, the second additional pipe section 15 is also away from the first heat sink 20 and the second heat sink 30 in space. In this case, even if the second additional pipe section 15 deforms to some extent due to the icing expansion of the heat exchange medium, the connection between the heat pipe 10 and the heat sink is not affected. Therefore, the heat dissipation module 100 provided in this embodiment of this application has the high use stability.

[0121] The first heat sink 20 and the second heat sink 30 may be metal heat sinks. For example, the metal may be an aluminum alloy, a copper alloy, stainless steel, or the like. However, this is not limited thereto. The first heat sink 20 includes a first substrate 21 and a plurality of first fins 22 disposed on the first substrate 21. The plurality of first fins 22 are grouped into two groups, the first fins 22 of each group are parallel and spaced, and the two groups of first fins 22 are spaced on two sides of the first substrate 21. The evaporation section 11 is attached to the first substrate 21, and is located between the two groups of first fins 22.

[0122] The second heat sink 30 includes a second substrate 31 and a second fin 32 disposed on the second substrate 31. A plurality of second fins 32 are grouped into two groups, the second fins 32 of each group are parallel and spaced, and the two groups of second fins 32 are spaced on two sides of the second substrate 31. The condensation section 13 is attached to the second substrate 31, and is located between the two groups of second fins 32.

[0123] During use, the first substrate 21 of the first heat sink 20 may be attached to one or some of the heat emitting components of the heat dissipation device, and the second substrate 31 of the second heat sink 30 may be attached to the another or other heat emitting components of the heat dissipation device. In this case, the heat pipe 10 is used as the heat bridge to connect the two heat sinks, and can transfer heat from one heat sink to the other heat sink, so that the two heat sinks can promote heat dissipation of each other, and utilization of heat dissipation fins on the heat sinks is high. Therefore, overall heat dissipation efficiency of the heat dissipation module 100 for the heat dissipation device can be improved, and a problem of local overheating caused by a poor local heat dissipation condition can be effectively avoided.

[0124] FIG. 8 is a diagram of an overall structure of another example of the heat dissipation module 100 according to an embodiment of this application. Compared with the embodiment shown in FIG. 7, the heat dissipation module 100 provided in this embodiment further includes a connecting plate 40, and the connecting plate 40 is connected to the first substrate 21 and the second substrate 31, so that the entire heat dissipation module 100 has high structural stability. The first substrate 21, the second substrate 31, and the connecting plate 40 may be formed by cutting a same metal plate (for example, an aluminum plate).

[0125] In addition, as shown in FIG. 8, a form of the heat pipe 10 in this embodiment is different from that of the heat pipe 10 in FIG. 7. In this embodiment, the heat pipe 10 is linear as a whole, and both the first additional pipe section 14 and the second additional pipe section 15 are cylindrical pipe sections. The first additional pipe section 14 extends to an outer side of the first substrate 21, so that the first additional pipe section 14 and the first heat sink 20 are away from and not in contact with each other in space, and the second additional pipe section 15 extends to an outer side of the second substrate 31, so that the second additional pipe section 15 and the second heat sink 30 are away from and not in contact with each other in space. Because the heat dissipation module 100 uses the heat pipe 10 provided in the foregoing embodiment, the heat dissipation module 100 also has technical effect corresponding to that of the heat pipe 10. Details are not described herein again.

[0126] In addition, an embodiment of this application further provides a heat dissipation device 1000. FIG. 9 is a diagram of an overall structure of an example of the heat dissipation device 1000 according to this embodiment of this application. FIG. 10 is a diagram of assembly of the heat dissipation module 100 and a circuit board 300 inside the heat dissipation device 1000 shown in FIG. 9. FIG. 11 is a diagram of a connection between the circuit board 300 and a heat emitting component 400.

[0127] As shown in FIG. 9 to FIG. 11, the heat dissipation device 1000 provided in this embodiment of this application includes a housing 200, the circuit board 300, and the heat dissipation module 100 provided in any one of the foregoing embodiments. The heat dissipation module 100 and the circuit board 300 are located in the housing 200, the heat emitting component 400 is disposed on the circuit board 300, and the heat dissipation module 100 is configured to dissipate heat for the heat emitting component 400.

[0128] Optionally, the heat dissipation device 1000 may be an electronic device. The electronic device may be, for example, a network device like a router, a server, a switch, or a communication base station, or may be a terminal device like a mobile phone, a notebook computer, a desktop computer, or a vehicle-mounted device. In a possible implementation, the heat dissipation device 1000 may alternatively be a vehicle (for example, an electric vehicle), that is, heat may be dissipated for a heat emitting component on the vehicle by using the heat dissipation module 100.

[0129] As shown in FIG. 10 and FIG. 11, there are a plurality of heat emitting components 400, the first heat sink 20 is connected to some (for example, one of the heat emitting components 400) of the heat emitting components 400, and the second heat sink 30 is connected to the other (for example, another of the heat emitting components 400) heat emitting components 400.

[0130] As shown in FIG. 10, the first substrate 21 of the first heat sink 20 is attached to one heat emitting component 400, and the second substrate 31 of the second heat sink 30 is attached to another heat emitting component 400. In this case, the heat pipe 10 is used as a heat bridge to connect the two heat sinks, and can transfer heat from one heat sink to the other heat sink, for example, transfer heat on the first heat sink 20 to the second heat sink 30, or transfer heat on the second heat sink 30 to the first heat sink 20. The heat pipe 10 can implement bidirectional heat transfer, so that the two heat sinks can promote heat dissipation of each other, and utilization of heat dissipation fins on the heat sinks is high. Therefore, overall heat dissipation efficiency of the heat dissipation module 100 for the heat dissipation device 1000 can be improved, and a problem of local overheating inside the heat dissipation device 1000 caused by a poor local heat dissipation condition can be effectively avoided.

[0131] Optionally, the circuit board 300 may be a printed circuit board (printed circuit board, PCB).

[0132] Optionally, the heat emitting component 400 may be any electrical element that can be disposed on the circuit board 300 and on which heat dissipation needs to be performed, for example, various processing chips or circuits. For example, the heat emitting component 400 may be a network processor, and in this case, the heat dissipation device 1000 may be a router. For another example, the heat emitting component 400 may alternatively be a central processing unit (central processing unit, CPU), a graphics processing unit (graphics processing unit, GPU) or a graphics card, a memory module (memory chip), or the like. In this case, the heat dissipation device 1000 may be a server.

[0133] As shown in FIG. 9 and FIG. 10, the heat dissipation device 1000 further includes a heat dissipation fan 500 configured to dissipate heat for the heat dissipation module 100. The heat dissipation fan 500 may be disposed close to the air intake vent 210 disposed on the housing 200. The heat dissipation fan 500 can inhale cold air outside the housing 200 into the inside of the housing 200, and blow the cold air to the first heat sink 20 and/or the second heat sink 30. Two heat dissipation fans 500 may be disposed, and are disposed in a one-to-one correspondence with the first heat sink 20 and the second heat sink 30. One heat dissipation fan 500 dissipates heat for the first heat sink 20, and the other heat dissipation fan 500 dissipates heat for the second heat sink 30. An air outlet vent (not shown in the figure) may be further disposed on the housing 200, so that hot air after heat exchange is discharged to an external environment of the housing 200.

[0134] Optionally, the heat dissipation fan 500 may be an axial fan, a cross-flow fan, or a centrifugal fan.

[0135] FIG. 12 is a diagram of another example of assembly of the heat dissipation module 100 and the circuit board 300. As shown in FIG. 12, a plurality of heat dissipation modules 100 may be disposed, and are configured to dissipate heat for a plurality of heat emitting components 400. Therefore, it can be ensured that the heat dissipation device 1000 has good heat dissipation effect. The plurality of heat dissipation modules 100 may be disposed parallel to each other, or may be disposed to cross each other, and may be disposed based on actual arrangement of the heat emitting components 400. In this case, more heat dissipation fans 500 may be correspondingly disposed.

[0136] For example, as shown in FIG. 11 and FIG. 12, there are four heat emitting components 400 on the circuit board 300, and two heat dissipation modules 100 may be attached to the circuit board 300 to dissipate heat for the four heat emitting components 400 at the same time. Four heat dissipation fans 500 may be disposed, to dissipate heat for the four heat sinks in a one-to-one correspondence.

[0137] FIG. 13 is a diagram of still another example of assembly of the heat dissipation module 100 and the circuit board 300. Compared with the heat dissipation module 100 in the foregoing embodiment, in this embodiment, the heat dissipation module 100 may have only one heat sink, namely, the second heat sink 30 connected to the condensation section 13, and no heat sink is disposed on the evaporation section 11. The evaporation section 11 may be directly attached to the heat emitting component 400. In this case, heat on the heat emitting component 400 is transferred to a heat dissipation component like the second heat sink 30 by using the heat pipe 10, and is finally dissipated to an environment. The heat dissipation component may further include, for example, the heat dissipation fan 500.

[0138] Optionally, in another implementation, the second heat sink may not be disposed on the condensation section 13, and in this case, the heat dissipation fan 500 directly dissipates heat for the condensation section 13.

[0139] Optionally, in another implementation, a heat dissipation fin may alternatively be directly disposed in the condensation section 13. For example, a plurality of heat dissipation fins are sleeved at an outer end of the condensation section 13 and spaced, and heat is dissipated for the heat dissipation fins by using the heat dissipation fan 500.

[0140] Because the heat dissipation device 1000 uses the heat pipe 10 provided in the foregoing embodiment, the heat dissipation device 1000 also has technical effect corresponding to that of the heat pipe 10. Details are not described herein again.

[0141] The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A heat pipe (10) for preventing icing expansion, comprising a pipe body (1) having a sealed cavity (2), wherein a capillary structure (3) and a heat transfer medium (4) are disposed in the sealed cavity (2), and the pipe body (1) comprises:

a main pipe section, wherein the main pipe section is sequentially divided into an evaporation section (11), a heat insulation section (12), and a condensation section (13) in a length direction, and the capillary structure (3) is located at least in a heat exchange cavity (2b) of the main pipe section; and

a first additional pipe section (14), wherein the first additional pipe section (14) is connected to an end part of the evaporation section (11), a first additional cavity (2a) is disposed in the first additional pipe section (14), the first additional cavity (2a) is used to accommodate all or a part of the heat transfer medium (4) when the heat pipe (10) is vertically placed and the first additional pipe section (14) is located below a gravity direction, and when the heat pipe (10) is mounted on a heat dissipation device that requires heat dissipation, the first additional pipe section (14) is not in contact with a heat emitting component of the heat dissipation device.

2. The heat pipe (10) according to claim 1, wherein when the heat pipe (10) is vertically placed and the first additional pipe section (14) is located below the gravity direction, the first additional cavity (2a) is capable of accommodating all heat transfer medium (4) that fails to be maintained inside the capillary structure (3).

3. The heat pipe (10) according to claim 1 or 2, wherein the pipe body (1) further comprises:
a second additional pipe section (15), wherein the second additional pipe section (15) is connected to an end part of the condensation section (13), a second additional cavity (2c) is disposed in the second additional pipe section (15), and the second additional cavity (2c) is used to accommodate the all or the part of the heat transfer medium (4) when the heat pipe (10) is vertically placed and the second additional pipe section (15) is located below the gravity direction.

4. The heat pipe (10) according to any one of claims 1 to 3, wherein a cross-sectional area of the first additional cavity (2a) is greater than a cross-sectional area of the heat exchange cavity (2b).

5. The heat pipe (10) according to any one of claims 1 to 4, wherein the first additional pipe section (14) is bent towards one side relative to the evaporation section (11), so that an included angle is formed between the first additional pipe section (14) and the evaporation section (11).

6. The heat pipe (10) according to any one of claims 1 to 5, wherein the capillary structure (3) extends into the first additional cavity (2a).

7. The heat pipe (10) according to any one of claims 1 to 6, wherein the first additional pipe section (14) comprises an end pipe section (a) and a transition pipe section (b), the end pipe section (a) is connected to the evaporation section (11) through the transition pipe section (b), the evaporation section (11) is a flat pipe, and the end pipe section (a) is a circular pipe.

8. The heat pipe (10) according to any one of claims 1 to 7, wherein the heat insulation section (12) is a bent pipe section capable of elastic deformation.

9. The heat pipe (10) according to any one of claims 1 to 8, wherein the capillary structure (3) is a wick, and the wick is attached to an inner wall of the pipe body (1).

10. A heat dissipation module (100), comprising:

a first heat sink (20);

a second heat sink (30); and

the heat pipe (10) according to any one of claims 1 to 9, wherein the evaporation section (11) is connected to the first heat sink (20), the condensation section (13) is connected to the second heat sink (30), and the first additional pipe section (14) is spaced apart from and is not in contact with the first heat sink (20) and the second heat sink (30).

11. The heat dissipation module (100) according to claim 10, wherein

the first heat sink (20) comprises a first substrate (21) and a first fin (22) disposed on the first substrate (21), and the evaporation section (11) is attached to the first substrate (21); and

the second heat sink (30) comprises a second substrate (31) and a second fin (32) disposed on the second substrate (31), and the condensation section (13) is attached to the second substrate (31).

12. A heat dissipation device (1000), comprising:

a circuit board (300), wherein a heat emitting component (400) is disposed on the circuit board (300); and

the heat dissipation module (100) according to claim 10 or 11, wherein the heat dissipation module (100) is configured to dissipate heat for the heat emitting component (400).

13. The heat dissipation device (1000) according to claim 12, wherein there are a plurality of heat emitting components (400), the first heat sink (20) is connected to some of the heat emitting components (400), and the second heat sink (30) is connected to the other heat emitting components (400).

14. The heat dissipation device (1000) according to claim 12 or 13, wherein the heat dissipation device (1000) further comprises a heat dissipation fan (500) configured to dissipate heat for the heat dissipation module (100).

15. The heat dissipation device (1000) according to any one of claims 12 to 14, wherein there are a plurality of heat dissipation modules (100), and are configured to dissipate heat for the plurality of heat emitting components (400).

16. A heat dissipation device (1000), comprising:

a heat emitting component (400);

the heat pipe (10) according to any one of claims 1 to 9, wherein the evaporation section (11) is connected to the heat emitting component (400), and the first additional pipe section (14) is not in contact with the heat emitting component (400); and

a heat dissipation component, configured to dissipate heat for the condensation section (13).

Drawing