A fin microchannel heat sink with artificial nucleation cavities

Abstract

The application relates to a fin micro-channel heat sink with an artificial nucleation cavity, comprising a cover plate and a bottom plate, wherein the cover plate is provided with a heat sink inlet and a heat sink outlet, the bottom plate is provided with a flow collecting groove and a micro-channel, the micro-channel is provided with fins, the fins are in a bending structure and surround the nucleation cavity, one side of the fin is provided with a notch, and the notch is communicated with the nucleation cavity; the number of the fins is multiple, the fins are arranged in an array, two adjacent rows of the fins are cross-distributed, and the notches of the fins are towards one side of the heat sink outlet. Compared with the prior art, the application has the advantages of good heat exchange effect and the ability to avoid heat transfer deterioration.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and in particular to a finned microchannel heat sink with an artificial nucleation cavity. Background Technology

[0002] With the rapid development of information technologies such as 5G and AI, the power consumption of electronic devices is increasing exponentially, leading to a surge in heat generation and placing a heavy burden on thermal management systems. Current thermal control systems face challenges such as miniaturization, high heat flux, and high temperature control accuracy, which urgently need to be addressed.

[0003] Currently, single-phase liquid cooling is the mainstream heat dissipation method for electronic devices. However, with the increasing integration of electronic devices, single-phase fluid cooling can no longer meet the requirements of heat flux density, and research focus has gradually shifted to two-phase fluid cooling. Due to its advantages of high specific surface area and high heat flux density, boiling heat transfer in microchannels has become a hot research topic in electronic device heat dissipation. In the process of microchannel boiling heat transfer, the thermal boundary layer and nucleation sites of nucleated boiling are two key factors for enhancing heat transfer. Existing technologies show that micro-needle structures can interrupt the development of the thermal boundary layer, and groove structures fabricated on the channel walls can provide artificial nucleation sites.

[0004] For example, utility model CN212695142U discloses a microchannel heat sink with a discontinuous inclined rib structure, belonging to the field of heat exchanger technology. Its structure includes an inlet and outlet structure, a microchannel structure, and a top cover. One end of the inlet and outlet structure is an inlet channel, and the other end is an outlet channel. The microchannel structure is disposed between the inlet and outlet channels and includes several inclined ribs arranged in a matrix on the bottom plate of the inlet and outlet structure. The top cover has a cooling medium inlet and a cooling medium outlet. The cooling medium flows through the microchannels with discontinuous inclined ribs, where the cross-section decreases, and vortices are formed locally, which helps to improve the heat exchange efficiency of the heat sink.

[0005] However, most studies only involve one of the microfin or groove structures, failing to combine the advantages of both, thus limiting the enhancement of heat transfer. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology, such as the single structure of the microchannel heat sink and the limited heat transfer effect, and to provide a finned microchannel heat sink with an artificial nucleation cavity.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A finned microchannel heat sink with an artificial nucleation cavity includes a cover plate and a base plate. The cover plate has a heat sink inlet and a heat sink outlet, and the base plate has a flow collection groove and a microchannel. Fins are arranged inside the microchannel. The fins have a bent structure and surround a nucleation cavity. A notch is provided on one side of each fin, and the notch communicates with the nucleation cavity. There are multiple fins arranged in an array, with adjacent rows of fins interleaved. The notches of the fins face the side of the heat sink outlet.

[0009] Preferably, the fin is a pincer-shaped fin, and the end of the pincer-shaped fin opposite to the notch has a pointed tip.

[0010] Preferably, the nucleation cavity of the pincer-shaped fin has a triangular structure, and the two sides of the notch of the pincer-shaped fin are parallel to each other and parallel to the flow direction of the coolant.

[0011] Preferably, the pincer-shaped fin includes a triangular tip and two triangular tails. The bottom of the triangular tip is provided with a triangular nucleation cavity. The triangular tails are fixed to the bottom of the triangular tip and are arranged opposite to each other to form a notch communicating with the nucleation cavity.

[0012] Preferably, the fin is a C-shaped fin, and the two sides of the notch of the C-shaped fin are parallel to each other and parallel to the flow direction of the coolant.

[0013] Preferably, the C-shaped fin includes a first arc segment, a first straight segment, a second arc segment, and a second straight segment connected end to end in sequence, wherein the second arc segment is coaxial with the first arc segment, and the first straight segment and the second straight segment are parallel to each other.

[0014] Preferably, the straight line of each row of fins is perpendicular to the direction of fluid flow, the difference in the number of fins between two adjacent rows is one, and the number of fins in the first row closest to the heat sink inlet is one more than the number of fins in the next row.

[0015] Preferably, the flow collection channel includes an inlet flow collection channel and an outlet flow collection channel distributed at both ends of the microchannel, with the inlet flow collection channel facing the heat sink inlet and the outlet flow collection channel facing the heat sink outlet.

[0016] Preferably, the cover plate is made of BF33 glass, the base plate is made of silicon, and the cover plate and the base plate are connected by anodic bonding.

[0017] Preferably, the flow channels and microchannels on the base plate are prepared by etching.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) This solution provides more artificial nucleation cavities by setting fins with nucleation cavities in the microchannel area, with the notches of the nucleation cavities facing the heat sink outlet. The structural characteristics of the nucleation cavities make it easier for the fluid inside to be superheated and vaporized, effectively enhancing the nucleation boiling heat transfer of the microchannel structure. Compared with the existing solution of etching grooves on the straight microchannel wall, the pincer-shaped fin solution provided by this invention can not only provide nucleation cavities, but also interrupt the development of the thermal boundary layer by using the staggered arrangement of the fins themselves, thus avoiding the heat transfer deterioration caused by the development of the thermal boundary layer in the downstream of the straight microchannel.

[0020] (2) This scheme uses a microchannel heat sink with pincer-shaped fins, combined with the cross distribution of two adjacent rows of fins along the flow direction of the coolant. The bubbles that grow in the nucleation cavity are carried forward by the surrounding fluid. When they encounter the tip outline of the downstream pincer-shaped fins, they are easily cut into multiple small bubbles, thereby reducing the risk of triggering the critical heat flux density downstream due to bubble blockage. Attached Figure Description

[0021] Figure 1 A schematic diagram of the heat dissipation structure provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the cover plate provided by the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the base plate provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of the pincer-shaped fin microchannel provided by the present invention;

[0025] Figure 5 This is a schematic diagram of the C-shaped finned microchannel provided by the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of the pincer-shaped fin provided by the present invention;

[0027] Figure 7 This is a schematic diagram of the structure of the C-row fins provided by the present invention;

[0028] In the diagram: 1. Cover plate, 2. Base plate, 3. Heat sink inlet, 4. Heat sink outlet, 5. Inlet manifold, 6. Microchannel, 7. Outlet manifold, 8. Pincer-shaped fin, 9. Nucleation cavity, 10. C-shaped fin; 81. Triangular tip, 82. Two triangular tails, 101. First arc segment, 102. First straight segment, 103. Second arc segment, 104. Second straight segment. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] Example 1

[0036] like Figures 1 to 3As shown, this embodiment provides a finned microchannel heat sink with an artificial nucleation cavity, including a cover plate 1 and a base plate 2. The cover plate 1 is provided with a heat sink inlet 3 and a heat sink outlet 4. The base plate 2 is provided with a flow collection groove and a microchannel 6. The microchannel 6 is provided with fins. The fins are bent and surround a nucleation cavity 9. One side of the fin is provided with a notch that connects to the nucleation cavity 9. There are multiple fins, which are arranged in an array. The fins in adjacent rows are interleaved. The notches of the fins face the side of the heat sink outlet 4.

[0037] Working principle: The bottom of the base plate 2 is in direct contact with the electronic equipment to absorb heat from the heat source, and the heat is dissipated through the cooling fluid. The cooling fluid is first injected into the collection groove on the base plate 2 through the heat sink inlet 3 on the cover plate 1. After accumulating in the collection groove, it flows into the microchannel 6 region under pressure, where it undergoes convective heat exchange with the bottom of the microchannel and the sidewalls of the fins, changing from a single phase to a gas-liquid two-phase state, and then flows out of the heat sink. During the heat exchange with the microchannel heat sink, the fluid in the nucleation cavity 9 enclosed by the fins is more likely to reach the superheat required for boiling because it cannot be cooled by the supercooled fluid in time. Therefore, bubbles are more likely to nucleate and grow in the nucleation cavity 9.

[0038] By incorporating fins with nucleation cavities 9 within the microchannel region, and positioning the notches of the nucleation cavities 9 towards the heat sink outlet, the structural characteristics of the nucleation cavities 9 facilitate superheating and vaporization of the fluid within them, providing more artificial nucleation cavities and effectively enhancing nucleation boiling heat transfer in the microchannel structure. Compared to existing methods that involve etching grooves on the straight microchannel walls, the pincer-shaped fin design provided by this invention not only provides nucleation cavities but also interrupts thermal boundary layer development through the staggered arrangement of the fins themselves, avoiding the heat transfer deterioration caused by downstream thermal boundary layer development in straight microchannels.

[0039] In this embodiment, as Figure 5 and Figure 7 As shown, the fin is a C-shaped fin 10. The two sides of the notch of the C-shaped fin 10 are parallel to each other and parallel to the flow direction of the coolant.

[0040] Specifically, the C-shaped fin 10 includes a first arc segment 101, a first straight segment 102, a second arc segment 103, and a second straight segment 104 connected end to end in sequence. The second arc segment 103 is coaxially arranged with the first arc segment 101, and the first straight segment 102 and the second straight segment 104 are parallel to each other.

[0041] In this embodiment, the straight line of each row of fins is perpendicular to the flow direction of the fluid, and the difference in the number of fins between two adjacent rows is one. The first row of fins near the heat sink inlet 3 has one more fin than the next row. By placing the fins of the next row between the two fins of the previous row and distributing them alternately, the probability of flow disturbance and downstream bubble breakage can be effectively increased.

[0042] In this embodiment, the flow collection channel includes an inlet flow collection channel 5 and an outlet flow collection channel 6 distributed at both ends of the microchannel 6. The inlet flow collection channel 5 is directly opposite the heat sink inlet 3, and the outlet flow collection channel 6 is directly opposite the heat sink outlet 4.

[0043] In this embodiment, the cover plate 1 is made of BF33 glass, and the base plate 2 is made of silicon. The cover plate 1 and the base plate 2 are connected by anodic bonding. The flow channels and microchannels 6 on the base plate 2 are fabricated by etching.

[0044] In this embodiment, the microchannel heat sink consists of two parts: a cover plate 1 and a base plate 2. The inlet and outlet of the microchannel heat sink are machined on the cover plate 1. The base plate is etched with a flow collection groove structure and a microchannel structure with an artificial nucleation cavity. The fins inside the microchannel are bent and arranged in a cross pattern. The walls of the fins are the main heat exchange areas, and the space enclosed by each fin is an artificial nucleation cavity.

[0045] Specifically, the microchannel heat sink is 30 mm long, 8 mm wide, and 1 mm thick. The cover plate and base plate are both 0.5 mm thick. Two holes, each 3 mm in diameter and 21 mm apart, are machined on the cover plate; these serve as the inlet and outlet of the microchannel heat sink, respectively. The base plate is etched with a 200 μm deep manifold and microchannel structure. The microchannel region is 10 mm long and 3.2 mm wide, with alternating pincer-shaped / C-shaped fins arranged within the channel. Along the fluid flow direction, the number of fins in each row alternates between 10 and 9, with a distance of 300 μm between adjacent rows and 320 μm between fins within the same row.

[0046] Example 2

[0047] This embodiment is basically the same as Embodiment 1, except that the key technical feature is as follows: Figure 4 and Figure 6 As shown, in this embodiment, the fin is a pincer-shaped fin 8, and the end of the pincer-shaped fin 8 opposite to the notch is provided with a pointed tip.

[0048] Among them, the nucleation cavity 9 of the pincer-shaped fin 8 has a triangular structure, and the two sides of the notch of the pincer-shaped fin 8 are parallel to each other and parallel to the flow direction of the coolant.

[0049] Specifically, the pincer-shaped fin 8 includes a triangular tip 81 and two triangular tails 82. The bottom of the triangular tip 81 is provided with a triangular nucleation cavity 9. The triangular tails 82 are fixed to the bottom of the triangular tip 81 and are arranged opposite to each other to form a notch that communicates with the nucleation cavity 9.

[0050] By employing a microchannel heat sink with pincer-shaped fins 8, and with the characteristic of the cross-distribution of two adjacent rows of fins along the flow direction of the coolant, the bubbles that grow in the nucleation cavity 9 are carried forward by the surrounding fluid. When they encounter the tip contour of the downstream pincer-shaped fins, they are easily cut into multiple small bubbles, thereby reducing the risk of triggering the critical heat flux density downstream due to bubble blockage.

[0051] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A finned microchannel heat sink with an artificial nucleation cavity, comprising a cover plate (1) and a bottom plate (2), wherein the cover plate (1) is provided with a heat sink inlet (3) and a heat sink outlet (4), characterized in that, The base plate (2) is provided with a flow collection groove and a microchannel (6). The microchannel (6) is provided with fins. The fins are bent and enclose a nucleation cavity (9). One side of the fins is provided with a notch, which connects to the nucleation cavity (9). There are multiple fins. The fins are arranged in an array. The fins in adjacent rows are intersected. The notch of the fins faces the side of the heat sink outlet (4). The fin is a pincer-shaped fin (8), and the pincer-shaped fin (8) has a pointed end opposite to the notch; the nucleation cavity (9) of the pincer-shaped fin (8) has a triangular structure, and the two sides of the notch of the pincer-shaped fin (8) are parallel to each other and parallel to the flow direction of the coolant; the pincer-shaped fin (8) includes a triangular tip (81) and two triangular tails (82), the bottom of the triangular tip (81) is provided with a triangular nucleation cavity (9), and the triangular tails (82) are fixed to the bottom of the triangular tip (81) and are arranged opposite to each other to form a notch that communicates with the nucleation cavity (9); Alternatively, the fin may be a C-shaped fin (10), with the two sides of the notch of the C-shaped fin (10) being parallel to each other and parallel to the flow direction of the coolant; the C-shaped fin (10) includes a first arc segment (101), a first straight segment (102), a second arc segment (103), and a second straight segment (104) connected end to end in sequence, the second arc segment (103) being coaxially arranged with the first arc segment (101), and the first straight segment (102) and the second straight segment (104) being parallel to each other.

2. The finned microchannel heat sink with an artificial nucleation cavity according to claim 1, characterized in that, The straight line of each row of fins is perpendicular to the direction of fluid flow. The difference in the number of fins between two adjacent rows is one. The number of fins in the first row near the heat sink inlet (3) is one more than the number of fins in the next row.

3. A finned microchannel heat sink with an artificial nucleation cavity according to claim 1, characterized in that, The flow collection channel includes an inlet flow collection channel (5) and an outlet flow collection channel (7) distributed at both ends of the microchannel (6). The inlet flow collection channel (5) is directly opposite the heat sink inlet (3), and the outlet flow collection channel (7) is directly opposite the heat sink outlet (4).

4. A finned microchannel heat sink with an artificial nucleation cavity according to claim 1, characterized in that, The cover plate (1) is made of BF33 glass, the base plate (2) is made of silicon, and the cover plate (1) and the base plate (2) are connected by anodic bonding.

5. A finned microchannel heat sink with an artificial nucleation cavity according to claim 1, characterized in that, The flow collection groove and microchannel (6) on the base plate (2) are prepared by etching.

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