Tesla type micro-channel heat sink combined with variable cross-section valve core and non-uniform arrangement

Abstract

The application provides a variable cross-section valve core and non-uniform arrangement combined Tesla type micro-channel heat sink, and relates to the technical field of electronic component heat dissipation. The application comprises a heat sink base body, the heat sink base body is integrally formed with a plurality of parallel micro-channel flow channels inside, a cover plate is sealingly connected with the heat sink base body to form a closed flow channel, and a cooling medium inlet and outlet are arranged on the cover plate, a plurality of valve cores are arranged in each micro-channel flow channel, the valve core is a fixed flow guide block, and a heat generating device can be installed below the heat sink base body, and a heat conductive interface material is arranged between the heat generating device and the heat sink base body. The application solves the problems of single structure design, lack of diversity of valve core geometric form and arrangement mode of the existing Tesla valve type micro-channel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic component heat dissipation, in particular to a Tesla type micro-channel heat sink combined with a variable cross-section valve core and non-uniform arrangement. BACKGROUND

[0002] With the continuous reduction of the size of electronic components, the performance and operation speed of chips continue to improve, and their heat power also increases rapidly. However, the area available for heat dissipation on the surface of the chip is gradually reduced, resulting in a significant increase in heat flux density, heat concentration, and other heat management problems. Currently, the power consumption of chips has generally exceeded 200W, and if there is a lack of efficient heat dissipation means, the heat inside the chip will quickly accumulate, causing the temperature to soar, leading to performance degradation, accelerated aging, and even thermal runaway and physical damage. The micro-channel cooling technology has become an important heat dissipation scheme for high heat flux density chips due to its high specific surface area, compact structure, and high heat transfer efficiency. However, the traditional flat rectangular micro-channel is limited by its simple structure and has difficulty in meeting the heat dissipation needs of high-performance chips in terms of heat transfer efficiency and temperature uniformity. Therefore, optimizing the internal structure of the micro-channel is a key way to improve its overall heat dissipation performance.

[0003] In this context, the Tesla valve has great potential in the field of microfluidics and chip thermal management due to its unique asymmetric geometric structure. In particular, in the micro-channel heat sink, the internal valve core structure can induce flow path deviation and generate turbulence effects when flowing in the opposite direction, effectively enhancing heat transfer performance and improving temperature field distribution uniformity. This structure does not rely on external control devices and has the advantages of low energy consumption, simple structure, and easy integration, making it an important research direction for achieving efficient chip thermal management.

[0004] In the prior art, researchers have studied the Tesla valve type micro-channel structure by changing the corresponding structural parameters to improve heat transfer capacity and found that different geometric parameters have an impact on heat transfer and flow performance. For example, increasing the guide angle and extending the side passage length will reduce Nu, and in addition, the rectangular cross-section has the best heat transfer performance. The performance of the pseudo-Tesla valve type micro-channel and the traditional straight channel shows that at Re = 800, the Nusselt number of the pseudo-Tesla valve type micro-channel is increased by 102.3%, and the friction factor is increased by 3.21 times, significantly enhancing the heat transfer effect. The symmetric Tesla valve type micro-channel is compared with the traditional rectangular micro-channel, and the results show that it has high heat transfer efficiency and effective heat performance balancing ability.

[0005] At present, the research on Tesla valve type microchannels still mainly focuses on traditional structure forms, such as arc-shaped or drop-shaped valve cores, and the geometric structures thereof are single, and the exploration of other new structures is still limited. In addition, the existing research generally adopts a valve core structure with uniform arrangement and equal cross section for simulation analysis, and lacks systematic research on non-uniform arrangement of valve cores and gradually changing cross section of valve core structures, so it is difficult to comprehensively reveal the influence mechanism of valve core arrangement and cross section change of valve cores on microchannel flow and heat exchange. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a Tesla valve type microchannel heat sink combined with a variable cross section valve core and non-uniform arrangement, which solves the problems of single structure design and lack of diversity of geometric form and arrangement of valve cores in the existing Tesla valve type microchannels.

[0007] To achieve the above-mentioned purpose, the present application provides the following scheme:

[0008] A Tesla valve type microchannel heat sink combined with a variable cross section valve core and non-uniform arrangement, comprising:

[0009] A heat sink base body, wherein a plurality of parallel microchannel flow channels are integrally formed inside the heat sink base body;

[0010] A cover plate, which is sealingly connected with the heat sink base body to form a closed flow channel, and a cooling medium inlet and outlet are arranged on the cover plate;

[0011] A plurality of valve cores, at least one of which is arranged in each microchannel flow channel, and the valve core is a fixed flow guide block;

[0012] The heat generating device can be installed below the heat sink base body, and a heat conducting interface material is arranged between the heat generating device and the heat sink base body.

[0013] Preferably, the spacing between the two adjacent valve cores is arranged in a non-uniform manner with equal difference along the main flow direction of the cooling medium.

[0014] Preferably, the cross-sectional area of each valve core continuously changes in the height direction perpendicular to the flow channel bottom surface, gradually expands or gradually shrinks from the flow channel bottom surface, and forms a variable cross section structure.

[0015] Preferably, the valve core is in the shape of an ellipse in plan view.

[0016] Preferably, the cross-sectional area of the valve core is any one of a gradually expanding structure gradually expanding upward from the flow channel bottom surface or a gradually shrinking structure gradually shrinking upward from the flow channel bottom surface.

[0017] Preferably, the heat sink base body and the cover plate are made of copper or copper alloy material.

[0018] Preferably, the heat-conducting interface material is a heat-conducting silicone grease.

[0019] Preferably, the cooling medium is one of deionized water or nanofluid.

[0020] Preferably, the micro-channel flow passage is provided with an inlet header at the inlet end and an outlet header at the outlet end.

[0021] The present application discloses the following technical effects:

[0022] The present application provides a variable cross-section valve core and non-uniform arrangement combined Tesla type micro-channel heat sink, comprising: a heat sink base, the heat sink base is integrally formed with a plurality of parallel micro-channel flow passages; a cover plate, the cover plate is sealingly connected with the heat sink base to form a closed flow passage, and a cooling medium inlet and outlet are provided on the cover plate; a plurality of valve cores, at least one valve core is provided in each micro-channel flow passage, the valve core is a fixed flow guide block; a heat generating device can be installed below the heat sink base, and a heat-conducting interface material is provided between the heat generating device and the heat sink base. The present application has a simple structure. During operation, the valve core induces fluid to generate backflow, vortex and flow splitting effect, thereby enhancing fluid disturbance and mixing, destroying and rebuilding the thermal boundary layer, to improve the heat exchange efficiency of the fluid and the wall surface, and to realize enhanced heat exchange. In addition, while maintaining moderate heat exchange capacity, the present application can effectively reduce the pressure drop. This is because the front part of the present application enhances fluid disturbance and destroys the boundary layer by a smaller spacing, improves the heat exchange capacity, and the rear part gradually increases the spacing, so that the flow tends to be stable, and the flow resistance is reduced, thereby achieving a good balance between heat exchange efficiency and flow resistance; the non-traditional elliptical valve core structure is adopted, compared with the existing Tesla valve structure, the elliptical profile has a continuous smooth curvature, which can effectively guide the smooth transition of the forward fluid, and at the same time form a strong disturbance area in the local area, thereby enhancing the heat convection heat exchange effect; the variable cross-section valve core structure design is adopted, compared with the traditional equal cross-section valve core, the variable cross-section valve core can reduce the risk of local pressure drop mutation while maintaining the flow guiding function. The variable cross-section design enables the fluid to transition more smoothly when flowing through the valve core area, reducing the pressure loss caused by the rapid change of velocity gradient, thereby helping to optimize the overall system pressure drop; the arrangement mode of increasing the valve core spacing in the flow direction is adopted, which avoids the problem of insufficient flow field development and rapid accumulation of pressure drop in the traditional equal spacing structure. The incremental spacing arrangement can effectively control the total pressure drop growth rate while ensuring the sustained effect of disturbance, and slow down the flow resistance accumulation trend. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 An exploded view of components provided for embodiments of the present application;

[0025] Figure 2 A schematic view of internal structure provided for embodiments of the present application;

[0026] Figure 3 A periodic unit of four microchannels provided for embodiments of the present application, wherein, Figure 3 (a) is a schematic view of a first valve core arrangement, Figure 3 (b) is a schematic view of a second valve core arrangement, Figure 3 (c) is a schematic view of a third valve core arrangement, Figure 3 (d) is a schematic view of a fourth valve core arrangement;

[0027] Figure 4 A plot of Nusselt number at different inlet velocities provided for embodiments of the present application;

[0028] Figure 5 A plot of pressure drop at different inlet velocities provided for embodiments of the present application;

[0029] Figure 6 A plot of comprehensive performance evaluation factor provided for embodiments of the present application.

[0030] BRIEF DESCRIPTION OF DRAWINGS

[0031] 1 - cover plate, 2 - heat sink base, 3 - heat-conducting silicone grease, 4 - heat-generating device, 1.1 - inlet, 1.2 - outlet, 2.1 - inlet header, 2.2 - outlet header, 2.3 - diverging valve core, 2.4 - converging valve core, 2.5 - constant cross-section valve core. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0034] As Figures 1-2 shown, the present application provides a variable cross-section valve core and non-uniform arrangement combined Tesla type microchannel heat sink, comprising:

[0035] A heat sink base body 2, which is internally integrally formed with a plurality of micro-channel flow passages parallel to each other;

[0036] A cover plate 1, which is sealingly connected with the heat sink base body 2 to form a closed flow passage, and is provided with a cooling medium inlet 1.1 and outlet 1.2 on the cover plate 1;

[0037] A plurality of valve cores, at least provided in each micro-channel flow passage, which are fixed flow guide blocks;

[0038] The heat generating device 4 can be installed below the heat sink base body 2, and a thermally conductive interface material is arranged between the heat generating device 4 and the heat sink base body 2.

[0039] Specifically, the variable cross-section valve core and the non-uniformly arranged Tesla-type micro-channel heat sink, comprising a heat sink base body 2, a cover plate 1 arranged above the heat sink base body 2, and a heat generating device 4 arranged below the heat sink base body 2, and a layer of high thermal conductivity thermal conductive silicone grease 3 coated between the heat sink base body 2 and the heat generating device 4. The heat sink base body 2 is integrally formed and arranged by a plurality of flow passages with the same structure, parallel and equidistant. The valve core of each flow passage is non-uniformly arranged, that is, the distance between the valve cores gradually increases along the flow direction, and the valve core shape is elliptical. The cover plate 1 is provided with an inlet 1.1 and an outlet 1.2, and the cooling medium flows into the inlet 1.1, enters each flow passage in the heat sink, and finally flows out of the outlet 1.2.

[0040] Further, the distance between the two adjacent valve cores is arranged in a non-uniform manner with an arithmetic progression along the main flow direction of the cooling medium.

[0041] Further, the cross-sectional area of each valve core continuously changes in the height direction perpendicular to the flow passage bottom surface, gradually expands or gradually shrinks from the flow passage bottom surface, forming a variable cross-section structure.

[0042] Further, the valve core is elliptical in plan view.

[0043] Specifically, the Tesla valve type micro-channel adopts an elliptical valve core structure, and through the completed numerical simulation research, this shape has better flow and heat exchange performance compared with the traditional water droplet-shaped valve core structure and rectangular fin micro-channel.

[0044] Further, the cross-sectional area of the valve core is any one of a gradually expanding structure gradually expanding upward from the flow passage bottom surface or a gradually shrinking structure gradually shrinking upward from the flow passage bottom surface.

[0045] Specifically, the variable cross-section valve core structure has two types, the first type is a gradually expanding valve core 2.3, the structure is taken the flow passage bottom surface as the reference surface, from bottom to top, the valve core cross-sectional area gradually expands; the second type of variable cross-section valve core structure is a gradually tapered valve core 2.4, the structure is taken the flow passage bottom surface as the reference surface, from bottom to top, the valve core cross-sectional area gradually decreases.

[0046] Further, the heat sink base body 2 and the cover plate 1 are made of copper or copper alloy material.

[0047] Further, the heat-conducting interface material is heat-conducting silicone grease 3.

[0048] Specifically, the spacing of the valve core increases in equal difference along the flow direction.

[0049] As shown in the drawings, in order to compare the advantages of the variable cross-section valve core and the non-uniform arrangement structure, the valve core structure with constant cross-sectional area and uniform arrangement and the valve core structure with constant cross-sectional area and non-uniform arrangement are also designed. Figure 3

[0050] The heat-conducting silicone grease 3 can eliminate the air in the contact interface between the heat generating device 4 and the heat sink bottom, improve the heat conduction efficiency, and thus enhance the heat exchange capacity between the heat sink and the heat generating device 4.

[0051] The heat sink base body 2 and the cover plate 1 are made of copper, and the heat generating device 4 is made of silicon.

[0052] The cooling medium can be deionized water or nanofluid.

[0053] Further, the micro-channel flow passage inlet end is provided with an inlet header 2.1, and the outlet end is provided with an outlet header 2.2.

[0054] Specifically, the working principle of the heat dissipation device of the application is as follows: the heat generated by the heat generating device 4 is first conducted to the heat sink base body 2 through the heat-conducting silicone grease layer 3. After the cooling medium enters from the inlet 1.1, it is distributed to each micro-channel flow passage through the inlet header 2.1, and in the flow process, it successively experiences splitting and converging, while continuously absorbing the heat of the channel wall surface. Under the guidance of the gradually expanding valve core 2.3, the gradually tapered valve core 2.4 or the equal cross-section valve core 2.5, the cooling medium deflects along the asymmetric structure channel, generates flow disturbance and local backflow, thereby forming a vortex structure in the channel. This process significantly enhances the fluid mixing efficiency and destroys the boundary layer, thereby improving the overall heat exchange performance. Finally, the cooling medium converges in the outlet header 2.2 and is discharged from the system through the outlet 1.2.

[0055] The specific size of the heat sink, the number of channels, the number and arrangement spacing of the valve cores, etc. can be determined according to actual heat dissipation requirements and process requirements.

[0056] ​According to another embodiment of the micro-channel heat sink structure described above, the micro-channel material is selected as copper, and the cooling medium is Fe3O4-water nanofluid with a volume fraction of 5%. The cooling medium flows in from the inlet 1.1, enters each micro-channel unit in the inlet header 2.1 respectively, is then gathered in the outlet header 2.2, and finally flows out from the outlet 1.2.

[0057] The numerical simulation calculation is performed by using COMSOL 6.1. In order to improve the efficiency of numerical calculation and the accuracy of simulation, the actual calculation model is a periodic unit of the present application. The numerical simulation method and model have been verified. In the numerical simulation, the velocity inlet is used, the fluid temperature at the inlet is 293.15 K, the pressure at the outlet is the standard atmosphere 101.25 kPa, and the two sides are periodic boundaries, which are similar to adiabatic conditions. The inlet velocities are 0.6 m / s, 0.9 m / s, 1.2 m / s, 1.5 m / s and 1.8 m / s respectively, and a heat flux density of 100 W / cm2 is applied to the bottom of the micro-channel.

[0058] Reference Figure 4 Nusselt coefficient display diagram and Figure 5 Inlet and outlet pressure drop display diagram. Compared with the conventional structure micro-channel, the Tesla valve type micro-channel described in the present application can effectively improve the system heat dissipation capacity. In addition, under the same valve core structure, the heat exchange capacity of the non-uniform arrangement method is higher than that of the uniform arrangement method, and further by changing the cross-sectional area of the valve core on the basis of the non-uniform arrangement method, although the heat exchange capacity is reduced, the inlet and outlet pressure drop is obviously reduced, so the variable cross-section valve core can effectively reduce the pump power consumption.

[0059] Figure 6 The present embodiment is a comprehensive performance evaluation factor display based on the conventional structure, and Figure 6 It can be seen that in the range of the inlet velocity studied (0.6 m / s to 1.8 m / s), the PEC of the four structures gradually decreases with the increase of the inlet velocity, which indicates that the increase of the flow rate will lead to the decline of the system comprehensive performance. In addition, under the same valve core structure, the comprehensive performance of the non-uniform arrangement method is higher than that of the uniform arrangement method. And under all inlet velocities, the PEC value corresponding to the gradually expanding type valve core and the non-uniform arrangement structure is the largest, so it has better comprehensive heat transfer performance.

[0060] By optimizing the conventional equal cross-section valve core to a variable cross-section structure and arranging the valve cores non-uniformly, the present application can effectively guide the redistribution and disturbance of the fluid in the micro-channel, enhance the fluid mixing and wall heat exchange capacity, further reduce the inlet and outlet pressure drop, thereby significantly improving the comprehensive performance index of the heat sink, and has good application prospect.

[0061] The various embodiments described in this specification are intended to be exemplary only. The various embodiments were chosen and described in order to best explain the principles of the application and its practical application, to thereby enable others skilled in the art to best utilize the application, and to best enable the present application to be performed with determination by those skilled in the art.

[0062] The principles and implementations of the present application have been described in the specification with reference to specific examples. The above description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation and application range will be changed. In view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core, characterized in that, include: The heat sink substrate has several parallel microchannels integrally formed inside it. A cover plate, which is sealed to the heat sink substrate to form a closed flow channel, and a cooling medium inlet and outlet are provided on the cover plate; Multiple valve cores are disposed in at least one microchannel, wherein the valve core is a fixed flow guide block; A heating element can be installed below the heat sink substrate, and a thermally conductive interface material is provided between the heating element and the heat sink substrate; The spacing between two adjacent valve cores is arranged in a non-uniform manner with equal arithmetic progressions along the main flow direction of the cooling medium. The cross-sectional area of ​​each valve core changes continuously and gradually in the height direction perpendicular to the bottom surface of the flow channel, gradually expanding or shrinking from the bottom surface of the flow channel to form a variable cross-section structure. The valve core is elliptical in planar projection.

2. The Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core according to claim 1, characterized in that, The cross-sectional area of ​​the valve core is either an expanding structure that gradually increases from the bottom surface of the flow channel upwards, or a contracting structure that gradually decreases from the bottom surface of the flow channel upwards.

3. The Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core according to claim 1, characterized in that, Both the heat sink substrate and the cover plate are made of copper or copper alloy.

4. The Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core according to claim 1, characterized in that, The thermal interface material is thermally conductive silicone grease.

5. The Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core according to claim 1, characterized in that, The cooling medium is either deionized water or nanofluid.

6. The Tesla-type microchannel heat sink combining a variable cross-section valve core and a non-uniformly arranged core according to claim 1, characterized in that, The microchannel flow channel is equipped with an inlet header at the inlet end and an outlet header at the outlet end.

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