Heat dissipation element and thermosiphon heat sink

Abstract

The embodiments of the present application disclose a heat dissipation element and a thermosiphon radiator for use in the field of electronic heat dissipation, comprising a substrate and a cover plate connected to each other to form a chamber, and a capillary layer; the substrate has a first plate surface and a second plate surface opposite each other, and the projection of the liquid level of the liquid phase change working medium contained in the chamber in a plane along the direction of gravity is not higher than the top of the projection of the heat source attached to the second plate surface; the capillary layer is provided in the chamber, and the bottom of the projection of the capillary layer in the plane along the direction of gravity is not higher than the bottom of the projection of the heat source attached to the second plate surface, and the top of the projection of the capillary layer in the plane along the direction of gravity is not lower than the top of the projection of the heat source attached to the second plate surface; the capillary layer is used to suck in the liquid phase change working medium and perform phase change heat exchange with the heat source; and the capillary layer is provided with a vapor passage for discharging the gas phase change working medium generated by the phase change from the capillary layer, thereby expanding the condensation space and improving the performance of the thermosiphon radiator.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on November 28, 2022, bearing application number 202211501414.3 and entitled "Heat Dissipation Element and Thermosiphon Heat Dissipator", the entire contents of which are incorporated herein by reference.

[0002] The embodiments of the present application relate to the electronic heat dissipation field, and in particular to a heat dissipation element.The embodiments of the present application further relate to a thermosiphon heat dissipator including the heat dissipation element described above. [Background technology]

[0003] Currently, the circulation of the phase-change working medium inside the thermosiphon radiator is entirely by gravity, that is, if the liquid level of the liquid phase-change working medium inside the thermosiphon radiator is made higher than the upper interface of the heat source in the vertical direction, the heat amount of the heat source can be fully absorbed by phase-change heat exchange. Summary of the Invention [Problem to be solved by the invention]

[0004] In the process of realizing the present invention, the inventors have found that the prior art has at least the following problems: The liquid level of the liquid phase-change working medium inside the current thermosiphon radiator is higher than the upper interface of the vertical heat source, occupying part of the space that can be used as the condensation area, thus limiting the performance of the current thermosiphon radiator.

[0005] The embodiments of the present application provide a heat dissipation element that can be applied to a thermosiphon heat sink to improve the performance of the thermosiphon heat sink. [Means for solving the problem]

[0006] An embodiment of the present application further provides a thermosiphon heat sink including the heat dissipation element described above.

[0007] In a first aspect, an embodiment of the present application provides a heat dissipation element for application in a thermosiphon heat dissipator, The thermosiphon radiator includes at least a capillary layer, a base plate and a cover plate connected to each other to form a storage chamber, the storage chamber being used for storing a phase-change working medium and communicating a working medium passage in a fin of the thermosiphon radiator; the substrate has a first plate surface and a second plate surface facing each other, the first plate surface is for forming the accommodation chamber, the second plate surface is for mounting a heat source, and a projection of a liquid surface of the liquid-phase-change working medium accommodated in the accommodation chamber on a plane along a gravity direction is not higher than a top of a projection of the heat source attached to the second plate surface; The capillary layer is provided in the accommodation chamber, and the bottom of the projection of the capillary layer on a plane along the gravity direction is not higher than the bottom of the projection of the heat source attached to the second plate surface, and the top of the projection of the capillary layer on a plane along the gravity direction is not lower than the top of the projection of the heat source attached to the second plate surface, Furthermore, the capillary layer is used to suck in the liquid phase change working medium and perform phase change heat exchange with the heat source, and the capillary layer is provided with a vapor passage for discharging the gas phase change working medium generated by the phase change from the capillary layer.

[0008] The heat dissipation element provided in the embodiment of the present application includes a capillary layer, and a substrate and a cover plate connected to each other to form a storage chamber, the substrate has a first plate surface and a second plate surface facing each other, the first plate surface is for forming the storage chamber, and the second plate surface is for mounting a heat source, and the projection of the liquid level of the liquid phase change working medium contained in the storage chamber on a plane along the gravity direction is not higher than the top of the projection of the heat source mounted on the second plate surface, the capillary layer is provided in the storage chamber, the bottom of the projection of the capillary layer on a plane along the gravity direction is not higher than the bottom of the projection of the heat source mounted on the second plate surface, and the top of the projection of the capillary layer on a plane along the gravity direction is not lower than the top of the projection of the heat source mounted on the second plate surface, and the capillary layer is used to suck in the liquid phase change working medium and perform phase change heat exchange with the heat source, and the capillary layer is provided with a vapor passage for discharging the gas phase change working medium generated by phase change from the capillary layer. The projection of the liquid level of the liquid-phase-change working medium contained in the accommodating chamber on a plane along the direction of gravity is not higher than the top of the projection of the heat source attached to the second plate surface, so that the liquid-phase-change working medium does not occupy the space that can be used as a condensation area. As a result, the space that can be used as a condensation area in the thermosiphon radiator using the heat dissipation element provided in the embodiments of the present application can be fully utilized, the condensation space of the thermosiphon radiator is expanded, and the performance of the thermosiphon radiator is improved.

[0009] In some embodiments of the heat dissipation element, the bottom of the projection of the capillary layer on a plane along the gravity direction is lower than the bottom of the projection of a heat source attached to the second plate surface; The steam passage is provided in a portion of the capillary layer whose projection on a plane along the direction of gravity is not lower than the bottom of a projection of a heat source attached to the second plate surface.

[0010] In some embodiments of the heat dissipation element, the bottom of the projection of the capillary layer on a plane along the gravity direction is flush with the bottom of the projection of a heat source attached to the second plate surface; and In the direction of gravity, the bottom of the capillary layer abuts against the bottom of the containing chamber.

[0011] In some embodiments of the heat dissipation element, the vapor passage is provided on a side of the capillary layer facing towards the first plate surface.

[0012] Some embodiments of the heat dissipation element further include a fill tube; the filling tube is used such that one end thereof communicates with the storage chamber and the other end thereof communicates with the outside; The filling tube is used to draw a vacuum and inject a liquid phase-change working medium into the storage chamber and the working medium passage.

[0013] In some embodiments of the heat dissipation element, the cover plate is provided with a communication hole, The communication hole is intended to connect the storage chamber and the working medium passage so that the gas-phase change working medium diffuses into the working medium passage through the communication hole, and the liquid-phase change working medium produced by condensation in the working medium passage flows back into the storage chamber through the communication hole.

[0014] In some embodiments of the heat dissipation element, the substrate is provided with a support structure; The support structure is provided on the first plate surface at a portion where a projection on a plane along the gravity direction is higher than a top of a projection of the capillary layer, The support structure includes a number of spaced apart support columns; The support pillar has one end connected to the first plate surface and the other end connected to the cover plate, and serves to support the storage chamber.

[0015] In some embodiments of the heat dissipation element, the cross section of the support post comprises a circle or a polygon.

[0016] In some embodiments of the heat dissipation element, the capillary layer comprises a capillary product formed by sintering metal powders of different particle sizes, a capillary product formed by sintering a multi-layer mesh-like structure, a capillary product formed by metal 3D printing, or a metal foam.

[0017] In some embodiments of the heat dissipation element, the liquid phase-change working medium includes any of a R134a working medium, a R22 working medium, a R1233zd working medium, and a fluorinated liquid.

[0018] In a second aspect, an embodiment of the present application provides a thermosiphon heat dissipator comprising a fin having working medium passages and a heat dissipation element according to any one of the first aspects, The fin is provided on a side of the cover plate facing away from the storage chamber, and the working medium passage communicates with the communication hole.

[0019] Since the thermosiphon heat sink provided in the examples of the present application has a heat dissipation element as described in any one of the first aspects, it is clear that it has the same technical effect as the heat dissipation element provided in the examples of the application.

[0020] In some embodiments of the thermosiphon heat sink, the substrate and the capillary layer, the substrate and the cover plate, and the cover plate and the fins are secured together in a welding manner.

[0021] In order to more clearly explain the technical solutions in the embodiments of the present application, the following briefly introduces the drawings necessary for the description of the embodiments. Obviously, the drawings in the following description are only some of the embodiments described in the present application, and those skilled in the art can also obtain other drawings from these drawings. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a schematic diagram of a heat sink disclosed in an embodiment of the present application. [Diagram 2] FIG. 13 is a schematic diagram of the configuration of another heat sink disclosed in an embodiment of the present application. [Diagram 3] FIG. 2 is a schematic diagram showing the configuration of a capillary layer disclosed in an embodiment of the present application. [Figure 4] FIG. 2 is a schematic diagram of a capillary layer including only vapor passages as disclosed in an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic diagram of a heat sink disclosed in an embodiment of the present application after assembly. [Figure 6] FIG. 2 is a schematic diagram of an assembled heat sink according to another embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application are described below in a clear and complete manner in combination with the drawings in the embodiments of the present application, and obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained based on the embodiments of the present application on the premise that those skilled in the art have not made any inventive efforts fall within the scope of protection of the present application.

[0024] In describing the embodiments of the present application, it should be explained that the orientations or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc. are orientations or positional relationships based on those shown in the drawings, and are merely intended to facilitate and simplify the description of the embodiments of the present application, and do not indicate or imply that the devices or elements shown must have a particular orientation, be configured and operated in a particular orientation, and should not be understood as limiting the present application.

[0025] In the description of the embodiments of the present application, it should be explained that unless otherwise clearly specified and limited, the terms "attached", "connected" and "connected" should be understood in a broad sense, for example, may be fixedly connected, may be detachably connected, may be integrally connected, may be mechanically connected, may be electrically connected, may be directly connected, may be indirectly connected via an intermediate medium, and may communicate the insides of two elements. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present application according to the specific situation.

[0026] With the continuous development of electronics and communication technology, there is a demand for improved heat dissipation efficiency of heat sinks. Conventional die-cast aluminum type heat sinks are heavy and have low heat dissipation efficiency, making it difficult to meet current heat dissipation requirements.

[0027] The main methods for improving the efficiency of heat sinks in the past include increasing the fin efficiency of heat sinks, optimizing the configuration of heat sinks to increase the convection heat transfer coefficient, etc. Among them, increasing the fin efficiency of heat sinks is a direct, fast and effective method, and by considering high thermal conductivity materials and composite materials such as graphene-metal composite materials, graphene coating on the surface, etc. instead of die-cast aluminum fins, good results have been obtained. Phase change heat exchange is a method of increasing the heat dissipation capacity by using the latent heat of the phase change working medium and gas-liquid circulation, and is still widely used in the field of electronic heat dissipation, such as temperature equalizing plates, heat pipes, inflation plate fins and thermosiphon heat sinks.

[0028] However, currently, the circulation of the phase-change working medium inside the thermosiphon radiator is entirely by gravity. In other words, if the liquid level of the liquid phase-change working medium inside the thermosiphon radiator is made higher than the upper interface (topmost part) of the heat source in the vertical direction (gravity direction), the heat amount of the heat source can be sufficiently absorbed by phase-change heat exchange. With such a design, the liquid level of the liquid phase-change working medium inside the thermosiphon radiator cannot be lower than the upper interface (topmost part) of the heat source in the vertical direction (gravity direction). If the liquid level of the internal liquid phase-change working medium is lower than the upper interface (topmost part) of the heat source in the vertical direction (gravity direction), the heat amount of the heat source cannot be sufficiently absorbed by phase-change heat exchange. In addition, the liquid phase-change working medium stored inside the thermosiphon radiator affects the range of the condensation region, and the more liquid phase-change working medium stored inside, the smaller the range that can be used as the condensation region becomes. This means that the performance of the thermosiphon radiator is deteriorated, and since the liquid level of the liquid phase change working medium inside the current thermosiphon radiator is higher than the upper interface (top) of the heat source in the vertical direction (gravity direction), it occupies a part of the space that can be used as the condensation region, i.e., the liquid phase change working medium that is higher than the upper interface (top) of the heat source occupies a part of the space that can be used as the condensation region, so the space that the thermosiphon radiator can use as the condensation region is not fully utilized, and the performance of the current thermosiphon radiator is limited. Based on this, the embodiments of the present application provide a heat dissipation element and a thermosiphon radiator that can improve the performance of the thermosiphon radiator.

[0029] First, an embodiment of the present application provides a heat dissipation element applied to a thermosiphon heat dissipator, as shown in FIG. 1, which is specifically as follows: The heat dissipation element provided in the embodiment of the present application at least includes a substrate 1 and a cover plate 3 connected to each other to form a accommodating chamber 101, which is used for accommodating a phase-change working medium and communicating the working medium passage in the fin of the thermosiphon heat sink, it should be understood that the accommodating chamber 101 is mainly used for the flow and phase change of the phase-change working medium, including a liquid phase-change working medium and a gas phase-change working medium, that is, in the accommodating chamber 101, there exists a liquid phase-change working medium and a gas phase-change working medium generated by the phase change of the liquid phase-change working medium, and the gas phase-change working medium in the accommodating chamber 101 can flow into the working medium passage in the fin of the thermosiphon heat sink and condense to become a liquid phase-change working medium. Here, the substrate 1 has a first plate surface and a second plate surface facing each other, and it should be understood that the first plate surface is the surface of the substrate 1 that is close to (or facing) the cover plate 3, and the second plate surface is the surface of the substrate 1 that is away from (or separated from) the cover plate 3, the first plate surface is for forming a storage chamber, and the second plate surface is for mounting a heat source 4, and the projection of the liquid level of the liquid-phase-change working medium contained in the storage chamber 101 on a plane along the direction of gravity (or the vertical direction, i.e., the direction perpendicular to the ground) is not higher than the top of the projection of the heat source 4 mounted on the second plate surface, and it should be understood that the projection of the liquid level of the liquid-phase-change working medium in the storage chamber 101 is lower than the bottom of the projection of the heat source 4. It may be lower, or it may be higher than the bottom of the projection of the heat source 4 but lower than the top of the projection of the heat source 4, or it may be flush with the top of the projection of the heat source 4, and is not specifically limited here. Preferably, the liquid level of the liquid phase change working medium in the accommodating chamber 101, projected on a plane along the gravity direction (or the vertical direction, i.e., the direction perpendicular to the ground), is lower than the top of the projection of the heat source 4. In this way, when ensuring the normal operation of the thermosiphon radiator, the filling amount of the liquid phase change working medium can be reduced, the mass of the thermosiphon radiator can be lighter, and meanwhile, the space that can be used as the condensation area in the thermosiphon radiator can be not occupied, and the condensation space can be expanded, thereby improving the performance of the thermosiphon radiator.This liquid phase change working medium (phase change working medium) is any fluid that can change between gas and liquid phases under the operating conditions of the radiator, and may be an R134a working medium (or refrigerant), an R22 working medium (or refrigerant), an R1233zd working medium (or refrigerant) or a fluorinated liquid, and is not specifically limited here.

[0030] The heat dissipation element further includes a capillary layer 2 provided in the containing chamber 101. The capillary layer 2 has a capillary force, specifically, the capillary layer 2 may be a capillary product formed by sintering metal powders of different particle sizes, thereby forming a continuous irregular porous medium to provide the necessary capillary force in the substrate, and the capillary layer may be a capillary product formed by sintering a multi-layer mesh-like structure, forming a capillary passage between the multi-layer grid to provide the capillary force. The capillary layer 2 may be a capillary product formed by metal 3D printing or a metal foam, that is, the capillary layer 2 includes any of a capillary product formed by sintering metal powders of different particle sizes, a capillary product formed by sintering a multi-layer mesh-like structure, a capillary product formed by metal 3D printing, and a metal foam, and is not specifically limited here. The substrate 1, the capillary layer 2 and the cover plate 3 are arranged opposite to each other in the vertical direction (or the direction of gravity), and it should be understood that the three members of the substrate 1, the capillary layer 2 and the cover plate 3 may be arranged parallel to each other, or any of the members may be arranged at an angle, and the specific arrangement is not limited here. Preferably, the substrate 1, the capillary layer 2 and the cover plate 3 are arranged parallel to each other in the direction of gravity (or the vertical direction). The bottom of the projection of the capillary layer 2 in a plane along the gravity direction is not higher than the bottom of the projection of the heat source 4 attached to the second plate surface, and the top of the projection of the capillary layer 2 in a plane along the gravity direction is not lower than the top of the projection of the heat source 4 attached to the second plate surface, that is, the top of the capillary layer 2 needs to be at least flush with the top of the heat source 4 in the gravity direction (or vertical direction) so that the liquid phase change working medium can fully absorb the heat amount of the heat source 4, that is, the projection of the heat source 4 in a plane along the gravity direction (or vertical direction) is completely contained in the capillary layer 2, and thus Even if the projection of the liquid level of the liquid phase-change working medium on a plane along the direction of gravity is lower than the top of the projection of the heat source 4, due to the action of the capillary layer, the liquid phase-change working medium is transported to a height corresponding to the top of the heat source 4, and by performing phase change heat exchange with the heat source 4 (the amount of heat absorbed by the phase-change working medium is from the heat source 4), it is ensured that the liquid phase-change working medium can fully absorb the heat of the heat source 4; that is, due to the presence of the capillary layer, the projection of the liquid level of the liquid phase-change working medium contained in the containment chamber 101 on a plane along the direction of gravity does not need to be higher than the top of the projection of the heat source 4.That is, there is an overlapping portion between the capillary layer 2 and the heat source 4 when projected on a plane along the gravity direction (vertical direction). It should be understood that the bottom of the capillary layer 2 is immersed in the liquid phase change working medium in the accommodating chamber 101, and the capillary layer 2 is used to suck the liquid phase change working medium to perform phase change heat exchange with the heat source 4, that is, based on the capillary force of the capillary layer 2, the liquid phase change working medium is sucked up to the corresponding capillary layer position in the overlapping portion, that is, the liquid phase change working medium is sucked up to the height corresponding to the heat source, and the liquid phase change working medium is subjected to phase change heat exchange with the heat source 4 to generate a gas phase change working medium.

[0031] In addition, the internal evaporative boiling surface of the current thermosiphon radiator is often a smooth wall surface, and the boiling superheat of the smooth wall surface is often high, so that the performance of the thermosiphon radiator is also reduced. Therefore, in the embodiment of the present application, a vapor passage is added to the capillary layer 2, and as shown in Figures 3 and 4, the capillary layer 2 is provided with a vapor passage 201 for discharging the gas phase change working medium generated by phase change from the capillary layer 2. In general, the top of the capillary layer 2 is lower than the top of the containing chamber 101 in the gravity direction (or vertical direction), and is usually flush with the top of the heat source, and the vapor passage 201 can be provided on the side facing the first plate surface of the capillary layer 2, that is, the vapor passage 201 is provided on the side of the capillary layer 2 close to (facing) the substrate 1, and the vapor passage 201 is provided at the same height as the heat source 4 in the gravity direction (or vertical direction). The vapor passage 201 is a continuous passage at the same height as the heat source 4 in the capillary layer 2, and the vapor passage 201 may be a continuous upward groove. The vapor passage 201 is for discharging the gas phase change working medium generated by phase change heat exchange to the vapor space above the capillary layer 2, and the vapor space is mainly the space between the top of the capillary layer 2 and the top of the containing chamber 101. It should be understood that after the liquid phase change working medium changes phase to become a gas phase change working medium, it can be quickly discharged to the upper vapor space along the continuous groove. Without the continuous vapor passage 201 (gas passage), the generated gas can only be discharged after passing through the entire capillary layer 2, which increases the resistance of the movement of the gas phase change working medium and increases the resistance of the liquid working medium flowing through the capillary layer. Therefore, by processing a continuous vapor passage 201 on the side of the capillary layer 2 closer to (towards) the substrate 1, the generated gas phase change working medium (vapor) can be quickly discharged upward, and at the same time, the capillary layer 2 (capillary structure) can also reduce the degree of superheat between the heat source 4 and the boiling temperature as part of the strengthening of the boiling surface.

[0032] It should be understood that the heat dissipation element in the embodiment of the present application is generally in a vertical position during operation, and in some cases, it is allowed to be obliquely arranged at a certain angle, which is not specifically limited herein, and the certain angle can be 15° or 20°, which is not specifically limited herein. When the liquid level of the liquid phase change working medium in the containing chamber is lower than the top of the heat source, the capillary force of the capillary layer in the containing chamber is utilized to suck the liquid phase change working medium below the containing chamber upward, and the liquid phase change working medium is transported to a height corresponding to the heat source 4, and exchanges phase change heat with the heat source 4.

[0033] Thus, the heat dissipation element provided in the embodiment of the present application includes a substrate and a cover plate connected to each other to form a storage chamber, and a capillary layer, the substrate has a first plate surface and a second plate surface facing each other, the first plate surface is for forming the storage chamber, and the second plate surface is for mounting a heat source, and the projection of the liquid level of the liquid phase change working medium contained in the storage chamber on a plane along the gravity direction is not higher than the top of the projection of the heat source mounted on the second plate surface, the capillary layer is provided in the storage chamber, the bottom of the projection of the capillary layer on a plane along the gravity direction is not higher than the bottom of the projection of the heat source mounted on the second plate surface, and the top of the projection of the capillary layer on a plane along the gravity direction is not lower than the top of the projection of the heat source mounted on the second plate surface, wherein the capillary layer is used to suck in the liquid phase change working medium and perform phase change heat exchange with the heat source, and the capillary layer is provided with a vapor passage for discharging the gas phase change working medium generated by the phase change from the capillary layer. The projection of the liquid level of the liquid-phase-change working medium contained in the accommodating chamber on a plane along the direction of gravity is not higher than the top of the projection of the heat source attached to the second plate surface, so that the liquid-phase-change working medium does not occupy the space that can be used as a condensation area. As a result, the space that can be used as a condensation area in the thermosiphon radiator using the heat dissipation element provided in the embodiments of the present application can be fully utilized, the condensation space of the thermosiphon radiator is expanded, and the performance of the thermosiphon radiator is improved. In one possible embodiment, a capillary layer is added in the accommodating chamber, and the capillary force of the capillary layer is used to suck in the liquid below, thereby performing phase change heat exchange with the heat source at a higher position. Due to the capillary effect of the capillary structure, the liquid phase change working medium lower than the top position of the heat source can be sucked to a certain height, so that the upper heat source can still convert and transfer heat in the form of phase change heat exchange, increasing the total area involved in the phase change heat exchange, improving the heat exchange efficiency, and reducing the amount of phase change working medium used, thereby expanding the two-phase space (also called the condensation space) and improving the heat dissipation capacity of the thermosiphon radiator using the heat dissipation element provided in the embodiments of the present application for the heat source at a higher position.

[0034] Furthermore, in the embodiments of the present application, the capillary layer 2 may be arranged so that the bottom of the projection of the capillary layer 2 in a plane along the direction of gravity is lower than the bottom of the projection of the heat source 4 attached to the second plate surface, i.e., the bottom of the heat source 4 is above the bottom of the containment chamber 101 in the direction of gravity, and the projection of the liquid level of the liquid phase change working medium contained in the containment chamber 101 in a plane along the direction of gravity (or vertical direction, i.e., the direction perpendicular to the ground) is not higher than the top of the projection of the heat source 4. The corresponding steam passage 201 of the capillary layer 2 is arranged in a portion of the capillary layer 2 whose projection on a plane along the gravity direction is not lower than the bottommost projection of the heat source 4 attached to the second plate surface; it should be understood that in this case, the bottom of the capillary layer 2 can draw the liquid phase change working medium upward to the top of the capillary layer 2 by capillary force, so that the entire heat source 4 can also convert and transfer heat with the liquid phase change working medium by the way of phase change heat exchange; the steam passage 201 can discharge the gas phase change working medium generated by phase change, so as to ensure the smooth flow of the liquid phase change working medium and the gas phase change working medium.

[0035] Furthermore, in the embodiment of the present application, the capillary layer 2 may be provided such that the bottom of the projection of the capillary layer 2 in a plane along the gravity direction is flush with the bottom of the projection of the heat source 4 attached to the second plate surface, and the bottom of the capillary layer 2 abuts against the bottom of the accommodation chamber 101 in the gravity direction; at the same time, the projection of the liquid level of the liquid phase change working medium contained in the accommodation chamber 101 in a plane along the gravity direction (or vertical direction, i.e., perpendicular to the ground) is higher than the lowest part of the projection of the heat source 4 attached to the second plate surface, but not higher than the top of the projection of the heat source 4; preferably, the projection of the liquid level of the liquid phase change working medium in a plane along the gravity direction (or vertical direction, i.e., perpendicular to the ground) is higher than the bottom of the projection of the heat source 4, but lower than the top of the projection of the heat source 4. That is, the bottom of the heat source 4 is at the same height as the bottom of the accommodation chamber 101 in the gravity direction. The liquid level of the liquid phase change working medium in the storage chamber 101 is lower than the top of the heat source 4 but higher than the bottom of the heat source 4. In such a case, the capillary layer 2 sucks up the liquid phase change working medium to a height corresponding to the top of the heat source 4 in order to sufficiently absorb the heat of the heat source 4, and the gaseous working medium generated by the phase change is discharged through the vapor passage 201 of the capillary layer 2.

[0036] 2, the heat dissipation element further includes a filling tube 6, which may be provided on the substrate 1 or on the cover plate 3, and is not specifically limited here, and the position and shape of the filling tube 6 may be various. Furthermore, the filling tube 6 has one end connected to the accommodating chamber 101 and the other end connected to the outside of the heat dissipation element, that is, the filling tube 6 has one end connected to the inside of the heat dissipation element and the other end connected to the outside of the heat dissipation element, and the filling tube 6 is used to perform vacuum drawing and liquid injection of the liquid phase change working medium to the accommodating chamber 101 and the working medium passage 501, that is, the filling tube 6 is used to perform vacuum drawing and liquid injection of all the communicating cavities inside the heat dissipation element, that is, the filling tube 6 is used to perform vacuum drawing and liquid injection of the liquid phase change working medium to the accommodating chamber 101 and the working medium passage 501.

[0037] Furthermore, the cover plate 3 includes a communication hole 301, and the shape of the communication hole 301 may be a parallel elongated hole or a plurality of circular holes, but is not specifically limited here. The communication hole 301 communicates the accommodation chamber 101 and the working medium passage 501, so that the gas phase change working medium diffuses into the working medium passage 501 through the communication hole 301, and the liquid phase change working medium condensed in the working medium passage 501 flows to the bottom of the accommodation chamber 101 through the communication hole 301. It should be understood that the communication hole 301 allows the phase change working medium to form a circulation circuit between the accommodation chamber 101 and the working medium passage 501, and further, the accommodation chamber 101 and the working medium passage 501 communicate with each other through the communication hole 301 of the cover plate 3, and the phase change working medium is injected into the accommodation chamber 101 of the heat dissipation element and can freely flow through the accommodation chamber 101 and the working medium passage 501.

[0038] Further, the substrate 1 is provided with a support structure, which is provided on the first plate surface of the substrate 1 at a portion where the projection on a plane along the gravity direction is higher than the top of the projection of the capillary layer 2, i.e., the support structure is provided on the first plate surface and above the capillary layer 2. The support structure includes several support columns 102 arranged at intervals, and the cross-sectional shape of the support columns 102 may be circular, triangular, rectangular or other polygonal, and is not specifically limited here. The support columns 102 are connected at one end to the first plate surface and at the other end to the cover plate 3, and are for supporting the containing chamber 101. It should be understood that the phase-change working medium is injected into the chamber of the containing chamber 101. The phase-change working medium has a large pressure when operating at a high temperature. When the heat source does not generate heat, the containing chamber 101 is easily deformed at low temperatures and in a negative pressure state during the filling process. The function of the support pillars 102 is to provide a sufficiently strong tensile and supporting force so that the receiving chamber 101 between the base plate 1 and the cover plate 3 does not deform under the effect of pressure.

[0039] An embodiment of the present application further provides a thermosiphon radiator, as shown in Fig. 5 and Fig. 6, the thermosiphon radiator includes a fin having a working medium passage 501 and a heat dissipation element as described above. It should be understood that the thermosiphon radiator includes a heat dissipation fin assembly 5, the heat dissipation fin assembly 5 is provided on the side of the cover plate 3 away from the accommodating chamber, the heat dissipation fin assembly 5 includes a plurality of fins having a working medium passage 501, that is, the fins are provided on the side of the cover plate 3 away from the accommodating chamber 101, and the working medium passage 501 of the fins communicates with the communication hole 301. It should be understood that each fin of the heat dissipation fin assembly 5 has a working medium passage 501, which is used for the gas phase change working medium generated by the phase change heat exchange to condense into a liquid phase change working medium in the working medium passage 501. The working medium passage 501 can be understood as an internal passage of the fin of the heat dissipation fin assembly 5, and the fin can be formed by welding two pieces of metal together, and further form an internal passage (i.e., the working medium passage 501) between the two pieces of metal. It should be understood that the gas phase change working medium generated by the phase change heat exchange can enter the working medium passage 501 of the heat dissipation fin assembly 5 of the thermosiphon heat dissipation device and be condensed into a liquid phase change working medium. The fin, as an extended heat dissipation surface, can exchange heat with the environment to reduce the fin surface temperature, and make the gas phase change working medium condense in the working medium passage 501 of the fin, and then flow under the fin by the action of gravity and return to the accommodation chamber 101.

[0040] Furthermore, in the thermosiphon heat sink provided in the embodiments of the present application, the substrate 1 and the capillary layer 2, the substrate 1 and the cover plate 3, and the cover plate 3 and the fins are fixed by welding, that is, the substrate 1, the capillary layer 2, the cover plate 3 and the fins of the heat dissipation fin assembly 5 can be connected to corresponding objects by welding.

[0041] In the embodiment of the present application, the radiator is first assembled by welding each part. The filling tube 6 draws out the air from all the communicating cavities in the radiator and injects the phase-change working medium. When the heat source 4 generates heat, the liquid phase-change working medium in the radiator changes phase by boiling, absorbs the heat of the heat source by the latent heat of vaporization, and at the same time, the liquid phase-change working medium changes to a gas phase-change working medium. Furthermore, the liquid level of the liquid phase-change working medium is lower than the top of the heat source 4, and the capillary force of the capillary layer 2 in the accommodating chamber 101 can suck the liquid phase-change working medium upward to a height corresponding to the top of the heat source 4, and exchanges phase-change heat with the heat source 4, and the high-temperature gas phase-change working medium thus generated is discharged into the vapor space above the capillary layer 2. The high-temperature gas phase-change working medium generated by the heat source 4 is in a high-pressure state and diffuses into the working medium passage 501 of the heat-dissipating fin assembly 5 through the communication hole 301 of the cover plate 3 by the drive of pressure. When the high-temperature gas phase-change working medium comes into contact with the inner surface of the heat dissipation fin in the working medium passage 501, the gas phase-change working medium condenses on the cold wall surface to become a liquid phase-change working medium, and releases heat. The process of quickly transferring heat from the heat source 4 to the fin is completed. The condensed liquid phase-change working medium flows downward along the inner wall surface of the fin due to gravity, and the circulation of the phase-change working medium is completed.

[0042] Finally, it should be noted that the above embodiments are merely for illustrating the technical solutions of the embodiments of the present application, and are not limiting. Although the embodiments of the present application have been described in detail with reference to the above embodiments, those skilled in the art should understand that those skilled in the art may still make amendments to the technical solutions described in the above embodiments, or make equivalent substitutions for some or all of the technical features thereof, and such amendments or substitutions will not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present application, and all of them should be included in the scope of the claims and description of the embodiments of the present application.

Claims

1. A heat dissipation element applied to a thermosiphon radiator, The thermosiphon radiator includes at least a capillary layer, a base plate and a cover plate connected to each other to form a storage chamber, the storage chamber being used for storing a phase-change working medium and communicating a working medium passage in a fin of the thermosiphon radiator; the substrate has a first plate surface and a second plate surface facing each other, the first plate surface is for constituting the accommodation chamber, the second plate surface is for mounting a heat source, and a projection of a liquid surface of the liquid-phase-change working medium accommodated in the accommodation chamber on a plane along a gravity direction is not higher than a top of a projection of the heat source attached to the second plate surface; The capillary layer is provided in the accommodation chamber, and the bottom of the projection of the capillary layer on a plane along the gravity direction is not higher than the bottom of the projection of the heat source attached to the second plate surface, and the top of the projection of the capillary layer on a plane along the gravity direction is not lower than the top of the projection of the heat source attached to the second plate surface, The capillary layer is used to suck in the liquid phase change working medium and perform phase change heat exchange with the heat source, and the capillary layer is provided with a vapor passage for discharging the gas phase change working medium generated by the phase change from the capillary layer.

2. The bottom of the projection of the capillary layer on a plane along the gravity direction is lower than the bottom of the projection of the heat source attached to the second plate surface; The heat dissipation element described in claim 1, characterized in that the vapor passage is provided in a portion of the capillary layer whose projection on a plane along the direction of gravity is not lower than the bottommost portion of the projection of a heat source attached to the second plate surface.

3. The bottom of the projection of the capillary layer on a plane along the gravity direction is flush with the bottom of the projection of a heat source attached to the second plate surface; and The heat dissipation element according to claim 1 , wherein a bottom of the capillary layer abuts against a bottom of the containing chamber in a gravitational direction.

4. 4. The heat dissipation element according to claim 1, wherein the vapor passage is provided on a side of the capillary layer facing the first plate surface.

5. Further comprising a fill tube; the filling tube is used such that one end thereof communicates with the storage chamber and the other end thereof communicates with the outside; 2. The heat dissipation element according to claim 1, wherein the filling tube is used for drawing a vacuum and injecting a liquid-phase-change working medium into the containing chamber and the working medium passage.

6. The cover plate is provided with a communication hole, The heat dissipation element described in claim 1, characterized in that the communicating hole is intended to connect the storage chamber and the working medium passage so that the gas phase change working medium diffuses into the working medium passage through the communicating hole, and the liquid phase change working medium condensed and produced in the working medium passage flows back into the storage chamber through the communicating hole.

7. The substrate is provided with a support structure; The support structure is provided on the first plate surface at a portion where a projection on a plane along the gravity direction is higher than a top of a projection of the capillary layer, The support structure includes a number of spaced apart support columns; The heat dissipation element according to claim 1 , wherein the support pillar has one end connected to the first plate surface and the other end connected to the cover plate, and serves to support the accommodation chamber.

8. The heat dissipation element according to claim 7 , wherein the cross section of the support post comprises a circle or a polygon.

9. The heat dissipation element of claim 1, wherein the capillary layer includes any one of a capillary product formed by sintering metal powders of different particle sizes, a capillary product formed by sintering a multi-layer mesh structure, a capillary product formed by metal 3D printing, and a metal foam.

10. The heat dissipation element according to claim 1 , wherein the liquid phase-change working medium comprises any one of a R134a working medium, a R22 working medium, a R1233zd working medium, and a fluorinated liquid.

11. A fin having a working medium passage and a heat dissipation element according to any one of claims 1 to 3, A thermosyphon radiator, wherein the fins are provided on a side of the cover plate facing away from the storage chamber, and the working medium passage communicates with the communication hole.

12. The thermosyphon radiator according to claim 11 , wherein the substrate and the capillary layer, the substrate and the cover plate, and the cover plate and the fins are fixed to each other by welding.

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