Three-period extremely-small curved surface radiator and printed circuit board

Abstract

The invention discloses a three-period extremely-small curved surface radiator and a printed circuit board, the three-period extremely-small curved surface radiator comprises a shell and a heat exchange body, the heat exchange body is embedded in the middle of the shell, one end of the shell is provided with a cold flow inlet, and the other end of the shell is provided with a cold flow outlet; a heat flow inlet and a heat flow outlet which are communicated with the interior of the heat exchange body are formed in the side wall of the shell, the heat exchange body is formed by integrally forming and stacking a plurality of three-period extremely-small-curved-surface unit cell structures, refrigerant channels and heating medium channels which are densely distributed in a staggered mode are formed in the shell, the cold flow inlet and the cold flow outlet are both communicated with the refrigerant channels, and the heat flow inlet and the heat flow outlet are communicated with the heating medium channels. Due to the fact that the heat exchange body is formed by stacking a plurality of three-period tiny curved surface unit cell structures in the shell, and the heating medium channels and the refrigerant channels which are staggered with each other are formed, hot fluid and cold fluid can be subjected to sufficient heat exchange in the heat exchange body, the heat exchange efficiency is high, and the flowing resistance is small.

Description

Technical Field

[0001] The present invention belongs to the field of heat exchangers, and particularly relates to a three-period minimal surface radiator and a printed circuit board. Background Art

[0002] The three-period minimal surface (TPMS) heat exchanger is a new type of high-efficiency heat exchanger that has emerged in recent years. Its manufacturing method is additive manufacturing technology (3D printing technology). The heat exchange structure in the heat exchanger that determines the heat exchange and flow performance is determined by the 3D printed model file. The minimal surface is a surface with a constant mean curvature of 0 and the smallest area within a given boundary. At present, the overall structure and boundary region of the heat exchanger are extremely prone to the phenomena of flow dead zones and uneven flow, resulting in a large influence of the boundary effect of the actual structure, thereby generating a large flow resistance and seriously affecting the heat exchange effect. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a three-period minimal surface radiator with a simple structure, good heat dissipation effect, and small flow resistance.

[0004] To achieve the above purpose, the technical solution of the present invention is as follows: A three-period minimal surface radiator includes a housing and a heat exchanger body. The heat exchanger body is embedded in the middle of the housing. One end of the housing is provided with a cold fluid inlet, and the other end of the housing is provided with a cold fluid outlet. A hot fluid inlet and a hot fluid outlet communicating with the inside of the heat exchanger body are provided on the side wall of the housing. The heat exchanger body is formed by integrally molding and stacking a plurality of three-period minimal surface unit cell structures, and staggered and dense refrigerant channels and heat medium channels are formed in the housing. The cold fluid inlet and the cold fluid outlet are both communicated with the refrigerant channels, and the hot fluid inlet and the hot fluid outlet are both communicated with the heat medium channels.

[0005] The beneficial effect of the above technical solution is that since the heat exchanger body is formed by stacking a large number of three-period minimal surface unit cell structures in the housing and forms intersecting heat medium channels and refrigerant channels, at this time, the hot fluid is introduced through the hot fluid inlet and flows through the heat medium channels, and finally flows out through the hot fluid outlet, while the cold fluid is introduced through the cold fluid inlet and flows through the refrigerant channels, and finally flows out through the cold fluid outlet. The hot fluid and the cold fluid are fully heat exchanged in the heat exchanger body, with high heat exchange efficiency and small flow resistance.

[0006] In the above technical solution, the porosity of the refrigerant channels and the heat medium channels both show a gradually changing trend of decreasing first and then increasing in the fluid flow direction.

[0007] The beneficial effects of the above technical solution are as follows: In this way, the pore size in the central area of the heat exchanger can be reduced, thereby reducing the flow dead zone. This can effectively improve the defect of the boundary effect in the three-period minimal surface unit cell structure, making the fluid flow more evenly, achieving the purpose of reducing the flow resistance and thus improving the heat transfer performance.

[0008] In the above technical solution, the three-period minimal surface unit cell structure of the heat exchanger is a TPMS structure.

[0009] The beneficial effects of the above technical solution are as follows: It has a large surface area, and the average curvature at each point is 0. Its heat transfer effect is good, and the flow resistance is small.

[0010] In the above technical solution, the three-period minimal surface unit cell structure is a Gyroid surface, a Diamond surface or a Lidinoid surface.

[0011] The beneficial effects of the above technical solution are as follows: In this way, the surface of the three-period minimal surface unit cell structure is soft, and the internal space is intricate, thereby further improving its heat transfer effect and reducing its flow resistance.

[0012] In the above technical solution, selection filters are provided at both ends of the heat exchanger and at the positions corresponding to the heat flow inlet and the heat flow outlet.

[0013] The beneficial effects of the above technical solution are as follows: In this way, the selection filters at both ends of the heat exchanger can only allow the cold fluid to enter and exit the refrigerant channel, while the selection filters at the heat flow inlet and the heat flow outlet can only allow the hot fluid to enter and exit the heat exchanger, that is, the heat medium channel and the refrigerant channel in the heat exchanger are isolated from each other.

[0014] In the above technical solution, the heat exchanger and the housing are integrally formed by 3D printing.

[0015] The beneficial effects of the above technical solution are as follows: It is convenient to prepare.

[0016] In the above technical solution, the housing and the heat exchanger are made of a photocuring resin or an alloy material.

[0017] The beneficial effects of the above technical solution are as follows: In this way, the overall structure strength of the three-period minimal surface radiator is high.

[0018] In the above technical solution, heat transfer fins are evenly distributed in the refrigerant channel and the heat medium channel.

[0019] The beneficial effects of the above technical solution are as follows: In this way, the heat transfer performance of the heat exchanger can be further improved.

[0020] In the above technical solution, both ends of the housing are in the shape of hemispherical shells.

[0021] The beneficial effects of the above technical solution are as follows: This makes the flow resistance of the cold fluid in the shell small.

[0022] The second object of the present invention is to provide a printed circuit board with a simple structure and good heat exchange effect.

[0023] To achieve the above object, the technical solution of the present invention is as follows: A printed circuit board includes the three-period minimal surface radiator as described above.

[0024] The beneficial effects of the above technical solution are as follows: It has high heat exchange efficiency and small flow resistance. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the solid wall surface of the Gyroid unit cell structure;

[0026] Figure 2 It is a schematic diagram of a porous channel of the Gyroid unit cell structure;

[0027] Figure 3 It is a schematic diagram of another porous channel of the Gyroid unit cell structure;

[0028] Figure 4 It is a front view of the heat exchanger in the embodiment of the present invention;

[0029] Figure 5 It is a front view of the first selection filter in the embodiment of the present invention;

[0030] Figure 6 It is a front view of the second selection filter in the embodiment of the present invention;

[0031] Figure 7 It is a cross-sectional view of the three-period minimal surface radiator described in the embodiment of the present invention;

[0032] Figure 8 It is a schematic diagram of the gradually changing cross-sections at both ends of the TPMS porous structure in the embodiment of the present invention;

[0033] Figure 9 It is a schematic diagram of the gradual change of the pores of the TPMS porous structure in the embodiment of the present invention;

[0034] Figure 10 It is a schematic diagram at the end of the gradual change of the pores of the TPMS porous structure in the embodiment of the present invention.

[0035] In the figure: 1. Shell, 11. Cold fluid inlet, 12. Cold fluid outlet, 13. Hot fluid inlet, 14. Hot fluid outlet, 2. Heat exchanger, 21. Selection filter; 21a. First selection filter; 21b. Second selection filter; 22. TPMS porous structure. Detailed Embodiments

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] As Figure 7 shown, this embodiment provides a three-period minimal surface radiator, including a housing 1 and a heat exchanger 2. The heat exchanger 2 is embedded in the middle of the housing 1. One end of the housing 1 is provided with a cold fluid inlet 11, and the other end of the housing 1 is provided with a cold fluid outlet 12. A heat fluid inlet 13 and a heat fluid outlet 14 communicating with the inside of the heat exchanger 2 are provided on the side wall of the housing 1. The heat exchanger 2 is formed by stacking a plurality of three-period minimal surface unit cell structures integrally, and forms a crisscrossed and densely arranged refrigerant channel and heat medium channel in the housing 1. The cold fluid inlet 11 and the cold fluid outlet 12 are both communicated with the refrigerant channel, and the heat fluid inlet 13 and the heat fluid outlet 14 are both communicated with the heat medium channel. Since the heat exchanger 2 is formed by stacking a large number of three-period minimal surface unit cell structures in the housing 1 and forms an interlaced heat medium channel and refrigerant channel, at this time, the hot fluid is introduced through the heat fluid inlet 13, flows through the heat medium channel, and finally flows out through the heat fluid outlet 14, while the cold fluid is introduced through the cold fluid inlet 11, flows through the refrigerant channel, and finally flows out through the cold fluid outlet 12. The hot fluid and the cold fluid are fully heat-exchanged in the heat exchanger 2, with high heat exchange efficiency and small flow resistance.

[0038] As Figures 8 - 10 shown, in the above technical solution, the porosity of the refrigerant channel and the heat medium channel both shows a gradually changing trend of first decreasing and then increasing in the fluid flow direction. In this way, the pore size in the central area of the heat exchanger 2 can be reduced, thereby reducing the flow dead zone, effectively improving the defect of the boundary effect of the three-period minimal surface unit cell structure, making the fluid flow more uniformly, achieving the purpose of reducing the flow resistance and thus improving the heat exchange performance.

[0039] The three-period minimal surface unit cell structure of the heat exchanger 2 is a TPMS structure, which has a large surface area and an average curvature of 0 at each point, with good heat exchange effect and small flow resistance; the three-period minimal surface unit cell structure is a Gyroid surface, a Diamond surface or a Lidinoid surface, so that the surface of the three-period minimal surface unit cell structure is soft and the internal space is intricate, thereby further improving its heat exchange effect and reducing its flow resistance.

[0040] As Figures 4 - 6As shown, in the above technical solution, the main body of the heat exchanger 2 is a TPMS porous structure 22, and selection filters 21 are provided at both ends of the TPMS porous structure 22 and at positions corresponding to the heat flow inlet 13 and the heat flow outlet 14. The selection filters at both ends of the TPMS porous structure 22 are the first selection filters 21a, and the selection filters at the heat flow inlet 13 and the heat flow outlet 14 are the second selection filters 21b. In this way, only cold fluid can enter and exit the refrigerant channel through the first selection filters 21a at both ends of the heat exchanger 2, and only hot fluid can enter and exit the heat medium channel of the heat exchanger through the second selection filters 21b at the heat flow inlet 13 and the heat flow outlet 14, that is, the heat medium channel and the refrigerant channel in the heat exchanger 2 are isolated from each other. In the above technical solution, the heat exchanger 2 and the housing 1 are integrally formed by 3D printing, which is convenient for preparation; in the above technical solution, the housing 1 and the heat exchanger 2 are made of a photocurable resin or an alloy material, so that the entire triply periodic minimal surface radiator has high structural strength; in the above technical solution, heat exchange fins are evenly distributed in the refrigerant channel and the heat medium channel, so as to further improve the heat exchange performance of the heat exchanger 2; in the above technical solution, both ends of the housing 1 are in the shape of hemispherical shells, so that the flow resistance of the cold fluid in the housing 1 is small. In this embodiment, the middle part of the housing is in the shape of a cylindrical tube, and both ends thereof are blocked by hemispherical shells. The cold fluid inlet and the cold fluid outlet are respectively arranged at the middle positions of both ends of the housing.

[0041] In this embodiment, the positions of the TPMS porous structure 22 corresponding to the heat flow inlet and the heat flow outlet are both concave (the concave part is hemispherical, and the second selection filter 21b is hemispherical).

[0042] In this embodiment, the selection filters at both ends of the heat exchanger are similar to a sieve plate structure, the holes of which are aligned and communicated with the refrigerant channel of the heat exchanger, and the rest is integrally formed with the heat exchanger to block the corresponding end of the heat medium channel. Similarly, the selection filters at the heat flow inlet and the heat flow outlet are curved surfaces and are also in the shape of a sieve plate structure, the holes of which are aligned and communicated with the heat medium channel at the corresponding position of the heat exchanger, and the rest is integrally formed with the heat exchanger to block the corresponding refrigerant channel.

[0043] In this embodiment, the TPMS structure is composed of TPMS surfaces. The TPMS surface feature is that the mean curvature at any point is zero, it is infinite and periodic in three-dimensional space, and is described by a level set equation, which means the isosurface composed of points with a function value of c. When calculating the level set equation with c = 0, the isosurface divides the space into sub-domains with equal volumes, and these sub-domains can be controlled by the isosurface constant, so that the volume can be expanded or contracted by offsetting from the zero value in the normal direction or the opposite direction.

[0044] In this embodiment, the pores (except for the pores at the heat flow inlet and heat flow outlet) around the TPMS porous structure 22 are blocked by the housing.

[0045] Example 1

[0046] This embodiment provides a three - periodic minimal surface heat sink, and its core feature is mainly reflected in that its TPMS structure is a Gyroid surface, and its level - set equation is: The Gyroid surface is obtained through Walled TPMS Unit Sells in ntop (as Figure 1 shown), which divides the space into two non - connected regions. Take the region as the first fluid domain (as shown in 1 and Figure 2 ), and the other region as the second fluid domain (as shown in Figure 3 ).

[0047] The performance of the three - periodic minimal surface heat sink prepared in this embodiment is as follows: The specific surface area of its gradient - type TPMS structure reaches 1996 m 2 / m 3 , which is 31 - 49% higher than that of the traditional heat exchanger structure, and is only slightly 0.1% smaller than the specific surface area of the uniform - type TPMS structure. When the Reynolds number Re is 1600, compared with the Nusselt number drag coefficient of the uniform - type TPMS structure under the same Re as a reference, the comprehensive evaluation index PEC ((Nu / Nu0) / (f / f0) 1 / 3 , the comparison of heat transfer capacity and flow resistance) is increased by 9.3%. Considering both flow and heat transfer aspects, in the case where the specific surface area and porosity are almost unchanged, this embodiment not only reduces the flow dead zone caused by the increase of the selection filter, but also improves the overall heat transfer efficiency of the heat exchanger. The heat transfer rate per unit volume in this embodiment is 71.4 MW / m 3 , the total heat transfer coefficient is 840 W / m 2 ×K, and the pressure drop per unit length in the flow direction is 268 kPa / m, all of which are higher than those of the uniform - type TPMS structure (65.3 MW / m 3 , 768 W / m 2 ×K, 180 kPa / m) under the same conditions, and the heat transfer rate per unit volume and the pressure drop per unit length in the flow direction are also much higher than those of the conventional printed circuit heat exchanger (PCHE) (11.4 MW / m 3 , 6.6 kPa / m) under the same conditions.

[0048] Example 2

[0049] Same as Embodiment 1, the difference is that in this embodiment, the TPMS structure is a Diamond surface, and the implicit function expression of the Diamond surface is cos(x)cos(y)cos(z) - sin(x)sin(y)sin(z) = c. The heat transfer rate per unit volume of the three-period minimal surface radiator provided in this embodiment is 68.4 MW / m 3 , and the overall heat transfer coefficient is 804 W / m 2 ×K, and the pressure drop per unit length in the flow direction is 206 kPa / m.

[0050] Embodiment 3

[0051] Same as Embodiment 1, the difference is that in this embodiment, the TPMS structure is a Lidinoid surface, and the implicit function expression of the Lidinoid surface is [sin(x)cos(y)sin(z) + sin(y)cos(z)sin(x) + sin(z)cos(x)sin(y)) - (cos(x)cos(y) + cos(y)cos(z) + cos(z)cos(x)] = c. The heat transfer rate per unit volume of the three-period minimal surface radiator provided in this embodiment is 60.2 MW / m 3 , and the overall heat transfer coefficient is 708 W / m 2 ×K, and the pressure drop per unit length in the flow direction is 296 kPa / m.

[0052] The embodiments of the present invention have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A three-period minimal surface heat sink, characterized in that: The invention comprises a shell (1) and a heat exchanger (2), wherein the heat exchanger (2) is embedded in the middle of the shell (1), a cold flow inlet (11) is provided at one end of the shell (1), and a cold flow outlet (12) is provided at the other end of the shell (1), and a hot flow inlet (13) and a hot flow outlet (14) are provided on the side wall of the shell (1) and are connected to the inside of the heat exchanger (2). The heat exchanger (2) is formed by stacking a plurality of three-periodic minimal surface unit cell structures in an integral manner, and a plurality of interlaced cold medium channels and hot medium channels are formed in the shell (1), the cold flow inlet (11) and the cold flow outlet (12) are both connected to the cold medium channels, and the hot flow inlet (13) and the hot flow outlet (14) are both connected to the hot medium channels.

2. The three-period minimal surface heat sink according to claim 1, characterized in that: The porosity of the cooling medium channel and the heating medium channel both presents a gradual trend of first decreasing and then increasing in the fluid flow direction.

3. The three-period minimal surface heat sink according to claim 1, characterized in that: The three-periodic minimal surface unit cell structure of the heat exchanger (2) is a TPMS structure.

4. The three-period minimal surface heat sink according to claim 3, characterized in that: The three-periodic minimal surface unit cell structure is a Gyroid surface, a Diamond surface or a Lidinoid surface.

5. The three-period minimal surface heat sink according to claim 1, characterized in that: Selection filters (21) are provided at both ends of the heat exchanger (2) and at positions corresponding to the heat flow inlet (13) and the heat flow outlet (14).

6. The three-period minimal surface heat sink according to claim 1, characterized in that: The heat exchanger (2) and the shell (1) are integrally formed by 3D printing.

7. The three-period minimal surface heat sink according to claim 6, characterized in that: The shell (1) and the heat exchanger (2) are made of light-curing resin or alloy material.

8. The three-period minimal surface heat sink according to claim 1, characterized in that: Heat exchange fins are evenly distributed in the refrigerant channel and the hot medium channel.

9. The three-period minimal surface heat sink according to claim 1, characterized in that: Both ends of the shell (1) are in the shape of a hemispherical shell.

10. A printed circuit board, characterized in that: It comprises a three-period minimal surface heat sink as described in any one of claims 1 to 9.

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