Heat sink including honeycomb core, and method for manufacturing the same

Abstract

To provide a novel heat sink that can realize higher heat radiation efficiency and rigidity.SOLUTION: A heat sink 10 mounted on a spacecraft includes: a faceplate 101 which is radiatively coupled to the outer space; and a base plate 102; a honeycomb core 120 which consists of a plurality of cells and connects the faceplate 101 and the base plate 102 in a height direction of the cells, where the faceplate 101 has at least one protrusion 101c for the base plate 102. A heat transport pipe having an inflow port RI and an outflow port RO is embedded in the honeycomb core 120 in a prescribed pattern, and heat transport fluid flowed from the inflow port RI circulates through the heat transport pipe, and flows out from the outflow port RO.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat sink that is radiatively coupled to space. [Background technology]

[0002] Heat sinks mounted on spacecraft such as artificial satellites are required to be small and lightweight, with high heat dissipation efficiency and rigidity. For this reason, honeycomb panels are used as the main structure of the heat sinks. In particular, Patent Document 1 discloses a honeycomb sandwich panel with an embedded heat pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-053100 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the heat pipe disclosed in Patent Document 1 transports heat using thermal conduction, and therefore is unable to achieve a high heat dissipation effect. In addition, although the heat pipe can increase the rigidity of the honeycomb panel, it is not possible to achieve a higher rigidity.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a new heat sink that can achieve higher heat dissipation efficiency and rigidity. [Means for solving the problem]

[0006] The heat sink according to the present disclosure is a heat sink mounted on a spacecraft, and includes a surface plate that is radiatively coupled to outer space, a base plate, and a honeycomb core that is made up of a plurality of cells and connects the surface plate and the base plate in the height direction of the cells, and the surface plate has at least one protrusion relative to the base plate. A method for manufacturing a heat sink according to the present disclosure includes stacking thermally conductive material using a three-dimensional modeling device to integrally form the base plate, the surface plate, and the honeycomb core. Effect of the Invention

[0007] According to the present invention, higher heat dissipation efficiency and rigidity can be achieved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a heat sink according to a first embodiment of the present disclosure as viewed from the front surface side. [Diagram 2] FIG. 2 is a perspective view of the heat sink of FIG. 1 as seen from the back side. [Diagram 3] FIG. 3 is a perspective view showing the internal structure of the heat sink of FIG. 1 from the rear side. [Figure 4] FIG. 4 is a plan view of the heat sink of FIG. [Diagram 5] FIG. 5 is a front view of the heat sink of FIG. [Figure 6] FIG. 6 is a side view of the heat sink of FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line II in FIG. 4, showing a schematic diagram of a first example of the heat sink. [Figure 8] FIG. 8 is a cross-sectional view taken along line II-II of FIG. 4, showing a schematic diagram of a first example of the heat sink. [Figure 9] FIG. 9 is a cross-sectional view taken along line III-III in FIG. 5, showing a schematic diagram of a first example of the heat sink. [Figure 10] FIG. 10 is a cross-sectional view taken along line III-III in FIG. 5, showing a schematic diagram of a second example of the heat sink. [Figure 11] FIG. 11 is a cross-sectional view taken along line III-III in FIG. 5, showing a schematic diagram of a third example of the heat sink. [Figure 12] FIG. 12 is a cross-sectional view taken along line IV-IV in FIG. 11, showing a schematic diagram of a third example of the heat sink. [Figure 13] FIG. 13 is a schematic diagram showing an enlarged side view and a plan view of a part of the heat sink in FIG. [Figure 14]FIG. 14 is a plan view of a heat sink according to the second embodiment of the present disclosure. [Figure 15] FIG. 15 is a side view of the heat sink of FIG. [Figure 16] FIG. 16 is a side view of a heat sink according to the third embodiment of the present disclosure. [Figure 17] FIG. 17 is a side view of a heat sink according to the fourth embodiment of the present disclosure. [Figure 18] FIG. 18 is a side view of a heat sink according to the fifth embodiment of the present disclosure. [Figure 19] FIG. 19 is a schematic configuration diagram showing an example of a liquid immersion cooling network system for a satellite equipped with a heat sink according to the present disclosure. [Figure 20] FIG. 20 is a perspective view showing a schematic configuration of the pressure vessel (network grid) in FIG. [Figure 21] FIG. 21 is a side cross-sectional view showing a schematic configuration of an axial pump in the immersion cooling network system illustrated in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Embodiment The heat sink according to one embodiment of the present invention has a structure in which a honeycomb core is sandwiched between a surface plate and a base plate, and the surface plate has one or more protrusions relative to the base plate. By having the protrusions on the surface plate, high heat dissipation efficiency and rigidity can be achieved.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to Figures 1 to 12. However, the components described in the following embodiments are merely examples, and are not intended to limit the technical scope of the present invention to only those components.

[0011] First, the appearance and internal structure of the heat sink 10 will be described with reference to Figures 1 to 6. For convenience of the following description, the width and depth directions of the heat sink 10 are defined as the X and Y directions, respectively, and the height direction of the heat sink 10 is defined as the Z direction. The Z direction is the height direction of the cells of the honeycomb core.

[0012] 1, 2, and 4 to 6, heat sink 10 has a rectangular shape in which surface plate 101 and base plate 102 are joined at mounting portions 103A and 103B. Surface plate 101 has protrusions 101c in the Z direction, and base plate 102 has a flat plate shape extending in the XY plane. Here, protrusions 101c in the shape of a quadrangular pyramid are shown as an example.

[0013] Mounting parts 103A and 103B are provided on both ends of heat sink 10 in the X direction, and a predetermined number of bolt holes 104A and 104B are provided at equal intervals on each. Pipe joints 105 and 106 are fixed to protrude from one side surface of heat sink 10 in the Y direction. As described below, pipe joints 105 and 106 correspond to the inlet RI and outlet RO of the heat transport fluid, respectively.

[0014] 3 and 4, a heat transport pipe 110 is disposed in the internal space between the surface plate 101 and the base plate 102, embedded in a honeycomb core 120. Both ends of the heat transport pipe 110 are connected to pipe joints 105 and 106, respectively. This allows the heat transport fluid that flows in from the pipe joint 105 to pass through the heat transport pipe 110 and flow out from the pipe joint 106. As the heat transport fluid flows through the heat transport pipe 110, the heat of the heat transport fluid is discharged from the surface plate 101 through the honeycomb core 120.

[0015] The surface plate 101, the base plate 102 and the heat transport pipe 110 are mechanically connected and integrated by the honeycomb core 120. An example of the configuration of the honeycomb core 120 that connects the surface plate 101 and the base plate 102 will be described below.

[0016] <Example 1> 7 to 9 show an example of the structure of a honeycomb core 120 in which the cell foil thickness of the mounting portion is increased. FIGS. 7 and 8 are cross-sectional views taken along lines II and II-II in FIG. 4, respectively, and FIG. 9 is a cross-sectional view taken along line III-III in FIG. 5. In this first example, the surface plate 101 and the base plate 102 are connected in the Z direction (cell height direction) by the honeycomb core 120. Therefore, the height of the cells of the honeycomb core is low at the mounting portions 103A and 103B, and the height of the cells gradually increases at the protruding portion 101c of the surface plate 101. For example, the height (thickness) of the heat sink 101 is about 10 to 30 mm, and the diameter of the heat transport pipe 110 is about 5 mm.

[0017] Furthermore, in the honeycomb core 120 according to the first example, the attachment parts 103A and 103B are formed of honeycomb cores 120A and 120B having a thicker cell foil thickness than the thin foil honeycomb core 120C of the protruding part 101c. However, the foil thickness of the thick foil honeycomb cores 120A and 120B is relatively thicker than that of the thin foil honeycomb core 120C, and each foil thickness is determined in consideration of the required strength and weight of the heat sink 10. The structure of the honeycomb cores of the attachment parts 103A and 103B will be mainly described below.

[0018] As shown in Figures 8 and 9, the bolt holes 104A and 104B in the mounting parts 103A and 103B are formed in a metal block 121A. Honeycomb cores 120A and 120B having a thick foil are formed around the metal blocks 121A and 121B in the mounting parts 103A and 103B. This can improve the strength of the mounting parts 103A and 103B.

[0019] <Second Example> Fig. 10 shows a configuration example of a honeycomb core 120 in which not only the mounting parts 103A and 103B but also the cell foil thickness around the heat transport pipe 110 is thickened. Fig. 10 is a cross-sectional view taken along line II in Fig. 4. In the honeycomb core 120 according to this second example, similar to the above-mentioned first example, the protruding part 101c is formed of a thin foil honeycomb core 120C, the mounting parts 103A and 103B are formed of thick foil honeycomb cores 120A and 120B, and further the periphery of the heat transport pipe 110 is formed of a thick foil honeycomb core 120D.

[0020] The thick foil honeycomb cores 120A and 120B can improve the strength of the mounting parts 103A and 103B. Also, the thick foil honeycomb core 120D surrounds the heat transport pipe 110, improving the strength of the entire heat sink 10. Furthermore, the heat of the heat transport pipe 110 is conducted to the face plate 101 through the thick foil honeycomb core 120D, so that the heat dissipation efficiency can be further improved.

[0021] However, the foil thicknesses of the thick foil honeycomb cores 120A, 120B, and 120D and the foil thickness of the thin foil honeycomb core 120C are relatively different dimensions, and may be determined taking into consideration the required strength and weight of the heat sink 10.

[0022] <Example 3> 11 to 13 show examples of the structure of a honeycomb core 120 in which the core size varies depending on the location. Fig. 11 is a cross-sectional view taken along line III-III in Fig. 5, Fig. 12 is a cross-sectional view taken along line IV-IV in Fig. 11, and Fig. 13 is an enlarged view showing a schematic view of a portion in which the cell size varies. As explained in the first and second examples, the surface plate 101 and the base plate 102 are connected in the Z direction (cell height direction) by the honeycomb core 120. Therefore, the cell height of the honeycomb core is low at the attachment portions 103A and 103B, and the cell height gradually increases at the protruding portion 101c of the surface plate 101.

[0023] In the honeycomb core 120 according to the third example, the cell size is smaller than that of other parts around the mounting parts 103A and 103B and the heat transport pipe 110. In other words, the mounting parts 103A and 103B and the periphery of the heat transport pipe 110 are formed of high-density honeycomb cores 130A, 130B and 130C, and the rest is formed of a low-density honeycomb core 131.

[0024] As shown in Figures 11 and 12, the bolt holes 104A and 104B in the mounting parts 103A and 103B are formed in the metal block 121A. The high density honeycomb cores 130A and 130B are formed around the metal blocks 121A and 121B. The high density honeycomb cores 130A and 130B have high strength because of their small cell size. In Figure 11, the high density honeycomb cores are shown with diagonal cross hatching, but this is for the purpose of clarifying the difference in density of the honeycomb cores on the drawing, and is merely for convenience.

[0025] 13, the high-density honeycomb core 130C surrounds the heat transport pipe 110. This improves the strength of the heat transport pipe 110 and the entire heat sink 10. Furthermore, the heat of the heat transport pipe 110 is conducted to the front panel 101 through the high-density honeycomb core 130C, further improving the heat dissipation efficiency.

[0026] 2. Other embodiments In the above-described embodiment, an example has been shown in which the surface plate 101 has one protrusion on the base plate 102. The present invention is not limited to this, and the surface plate 101 may have multiple protrusions. By having the surface plate 101 have multiple protrusions, it is possible to obtain even higher heat dissipation efficiency and rigidity. Below, several examples of heat dissipation plates having multiple protrusions are given. However, the same reference numbers are used for components having the same functions as in the above-described embodiment, and explanations thereof will be omitted.

[0027] As shown in Fig. 14 and Fig. 15, the surface plate 201 of the heat sink 20 has two protrusions 201c1 and 201c2. The surface plate 201 and the base plate 102 are mechanically connected by the honeycomb core 120 (not shown) as described above. A heat transport pipe 210 is embedded in the honeycomb core 120. Here, the heat transport pipe 210 has a shape corresponding to the two protrusions 201c1 and 201c2. Needless to say, the heat transport pipe 210 may have the same shape as the heat transport pipe 110 in the above embodiment.

[0028] 15, when two protrusions 201c1 and 201c2 are formed on the front plate 201, it is desirable to set the inclination angle θ between the opposing surfaces of the protrusions and the base plate 102 so that each surface avoids radiation from the other surface as much as possible. It is desirable to set θ<45° at least.

[0029] The shape of the protrusions on the surface plate is not limited to the truncated quadrangular pyramid shown in the above embodiment. Some examples of the shape of the protrusions are given below.

[0030] As shown in Fig. 16, the surface plate 201 may have pyramidal convex portions 201d1 and 201d2, or may have dome-shaped convex portions 201e1 and 201e2 with curved surfaces, as shown in Fig. 17.

[0031] Furthermore, three or more protrusions may be formed on the front panel 201. As shown in FIG. 18, three protrusions 201f1 to 201f3 may be provided. Alternatively, the protrusions may be arranged in multiple rows in staggered positions, or may be arranged randomly. In the side views of FIGS. 15 to 18, the number of protrusions may be a multiple of two or a multiple of three. In any case, the surface area of ​​the front panel 201 is increased, improving the heat dissipation efficiency.

[0032] 3. Manufacturing method The above-mentioned heat sink 10 or 20 can be formed by sequentially stacking thermally conductive materials (such as aluminum) using a three-dimensional modeling device (hereinafter referred to as a 3D printer). By using a 3D printer, the specifications of the honeycomb core 120 (cell size, foil thickness, core height, number of protrusions, etc.) can be freely adjusted, making it possible to form the above-mentioned heat sink 10 or 20. In addition, since the surface plate, base plate, and honeycomb core that constitute the heat sink can be integrally stacked, a process of bonding each of them is not required. This eliminates the need for adhesives (such as epoxy adhesives), making it possible to use the heat sink in high temperature ranges. Furthermore, since the heat sink can be integrally formed with high precision, it is lightweight and highly rigid.

[0033] When using a 3D printer in an environment where gravity is applied vertically, it is not possible to simply stack relatively long components in the horizontal direction. Therefore, in the design stage of the heat sink 10 or 20, it is desirable to design in advance that the stacking of each part by the 3D printer has an inclination of 45° or more with respect to the horizontal direction.

[0034] For example, in Fig. 9, when the heat sink 10 is laminated in the Y direction using a 3D printer, each component is designed to be inclined at 45° or more with respect to the X direction. In Fig. 9, the piping route is determined so that the heat transport pipe 110 is inclined at 45° or more. Also, the metal blocks 121A and 121B are arranged so that each side is inclined at 45° or more. The same applies to the second example and the third example shown in Fig. 11.

[0035] 4. Application Examples The above-mentioned heat sink 10 or 20 can be applied to a radiator of a satellite. An example of application will be described below.

[0036] 19, a satellite 300, which is a spacecraft, is equipped with radiators 301a and 301b for dissipating heat into space, and various mission equipment 302a and 302b. The heat sink 10 or 20 according to the above-mentioned embodiment is used for each of the radiators 301a and 301b. The heat sink 10 or 20 is fixed to the main body mounting part of the satellite 300 with bolts through the bolt holes 104A and 104B of the mounting parts 103A and 103B.

[0037] In addition, the main electronic devices such as computers in the satellite 300 are immersed in a coolant (heat transport fluid) in pressure vessels G1 to G3 for liquid immersion cooling. Each pressure vessel Gi has a coolant inlet IL i and refrigerant outlet OL i (where i is an arbitrary integer equal to or greater than 1, but here i=1, 2, or 3). Pressure vessels G1 to G3, radiator 301, and control valves VL1 and VL2 constitute a heat transport network through a plurality of flexible pipes 303 through which a refrigerant flows.

[0038] The heat transport network may be configured so that immersion cooling can be efficiently performed in each pressure vessel. The refrigerant that has been heat exchanged in the radiator 301 flows into each pressure vessel, and the refrigerant that flows out from each pressure vessel returns to the radiator 301. In particular, the control valves (VL1 and VL2) are controlled so that the required amount of refrigerant is supplied to the pressure vessel that requires cooling.

[0039] In FIG. 19, the control valve VL1 is connected to the refrigerant outlet RO of the radiator 301a. 1 The refrigerant flowing out from the control valve VL1 is distributed between the pressure vessels G1 and G3. 1 The refrigerant that flows into the pressure vessel G1 cools the electronic equipment in the pressure vessel G2 by immersion and flows out of the refrigerant outlet OL 1 The refrigerant flows from the control valve VL1 to the refrigerant inlet IL of the pressure vessel G3. 3 The refrigerant that flows into the pressure vessel G3 cools the electronic equipment in the pressure vessel G3 by immersion and flows out of the refrigerant outlet OL 3 to the refrigerant inlet RI of the radiator 301a 1 Flows into.

[0040] Refrigerant outlet RO of radiator 301b 2 The refrigerant flowing out from the pressure vessel G2 enters the refrigerant inlet IL 2 The electronic equipment in the pressure vessel G2 is immersed in the liquid to cool it, and the refrigerant flows into the refrigerant outlet OL 2 The control valve VL2 directs the refrigerant flowing from the pressure vessels G1 and G2 to the refrigerant inlet RI of the radiator 301b. 2 to be discharged.

[0041] A forced flow generator for circulating the coolant in the heat transport network is provided in a flexible pipe 303 connected to the coolant outlet of the radiator 301. In this embodiment, an axial pump P1 is used as the forced flow generator, and the axial pump P1 is connected to the coolant outlet RO of the radiator 301a. 1 The axial flow pump P2 is provided on a flexible pipe 303 connecting the refrigerant outlet RO of the radiator 301b to the control valve VL1. 2 and the refrigerant inlet IL of pressure vessel G2 2 The flexible pipe 303 is provided to connect the

[0042] In this way, by employing the heat sink 10 or 20 according to the above-described embodiment for the radiators 301a and 301b, it is possible to realize a small, lightweight, highly rigid and highly efficient heat dissipation device.

[0043] Assume that electronic equipment (mission edge) connecting to mission equipment 302a is built in pressure vessel G1, electronic equipment (mission edge) connecting to mission equipment 302b is built in pressure vessel G2, and electronic equipment (OBC: On Board Computer) that controls the entire satellite is built in pressure vessel G3. The electronic equipment of each pressure vessel can communicate with the electronic equipment of other pressure vessels or the mission equipment 302a, 302b through the intra-satellite network NET. As will be described later, the OBC of pressure vessel G3 controls the control valves VL1, VL2 through the intra-satellite network NET or another network.

[0044] Hereinafter, each of the pressure vessels G1 to G3 will be referred to as "pressure vessel G," and the structure of the pressure vessel G will be described with reference to FIG.

[0045] 20, a pressure vessel G for immersion cooling comprises a sealed cylindrical vessel body 401, a lid 402 is fixed to the bottom surface of the vessel body 401, and a coolant 403 is sealed inside the pressure vessel. The lid 402 is provided with a coolant inlet IL through which the coolant flows into the vessel and a coolant outlet OL through which the coolant flows out to the outside. A support 404 fixed to the lid 402 is provided inside the pressure vessel G, and an electronic device 405 is fixed to the support 404. Thus, the coolant flows in from the coolant inlet IL, flows over the electronic device 405, transferring heat or air bubbles, and flows out from the coolant outlet OL to the outside.

[0046] The lid 402 is also provided with terminals 406 and 407 for connection to the intra-satellite network NET. The electronic device 405 can communicate with electronic devices G in other pressure vessels or mission equipment through the terminals 406 and 407.

[0047] The coolant 403 is a liquid having electrical insulation and thermal conductivity, and preferably contains hydrogen atoms in order to moderate and shield neutron radiation. As the coolant 403, for example, a liquid such as a fluorocarbon substitute or polyester can be used.

[0048] As shown in Fig. 21, an axial flow pump P is provided inside a flexible pipe 303. The axial flow pump P is composed of a motor 311 and a fan 312 attached to the rotating shaft of the motor 311. By rotating the fan 312, a flow 313 of a refrigerant is generated inside the flexible pipe 303. The rotation speed of the motor 311 can be controlled by a control unit provided in the pressure vessel which performs main control.

[0049] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-mentioned embodiments. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments. [Industrial Applicability]

[0050] The present invention is applicable to radiators in spacecraft. [Explanation of symbols]

[0051] 10, 20 Heat sink 101, 201 Surface plate 101c Convex part 102 Base plate 103A, 103B mounting part 104A, 104B Bolt holes 105 Pipe Fittings 106 Pipe Fittings 110, 210 Heat transport pipe 120 Honeycomb core 120A, 120B, 120D foil thickness honeycomb core 120C thin foil honeycomb core 121A, 121B Metal block 130A, 130B, 130C High density honeycomb core 131 Low density honeycomb core

Claims

1. A heat sink mounted on a spacecraft, comprising: A surface plate that is radiatively coupled to space; A base plate and A honeycomb core that is made up of a plurality of cells and connects the surface plate and the base plate in a height direction of the cells; wherein the surface plate has at least one protrusion relative to the base plate.

2. The heat sink according to claim 1 , wherein the face plate has a plurality of protrusions.

3. 3. The heat sink according to claim 1, wherein the honeycomb core has a mounting portion for mounting to the spacecraft, the mounting portion being made of a honeycomb core of thermally conductive foil that is thicker than other portions.

4. 3. The heat sink according to claim 1, wherein the honeycomb core has a mounting portion for mounting to the spacecraft, the mounting portion being made of a honeycomb core having a smaller cell size than other portions.

5. 3. A heat sink plate as described in claim 1 or 2, wherein heat transport pipes having an inlet and an outlet for a heat transport fluid are embedded in the honeycomb core in a predetermined pattern, and the heat transport fluid flowing in from the inlet flows through the heat transport pipes and flows out from the outlet.

6. 6. The heat sink according to claim 5, wherein the cells around the heat transport pipe are made of a honeycomb core having a smaller cell size than the other portions.

7. 7. The heat sink according to claim 6, wherein the honeycomb core is provided with a mounting portion for mounting to the spacecraft, the mounting portion being made of a honeycomb core having a smaller cell size than other portions.

8. A method for manufacturing the heat sink according to claim 1 or 2, comprising the steps of: A method for manufacturing a heat sink, comprising stacking thermally conductive material using a three-dimensional modeling device to integrally form the base plate, the surface plate and the honeycomb core.

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