Novel open type micro-channel radiator structure and method

Abstract

The invention provides a novel open type micro-channel radiator structure and method, and belongs to the field of electronic device heat dissipation, the novel open type micro-channel radiator structure comprises a cover plate and a micro-channel cold plate, the cover plate is provided with a cover plate liquid inlet and a cover plate liquid outlet, a groove is arranged below the cover plate, a cover plate inlet liquid collection area is arranged in the groove close to the cover plate liquid inlet, and a cover plate outlet liquid collection area is arranged in the groove close to the cover plate liquid outlet. A cover plate outlet liquid collecting area is arranged in the groove close to the cover plate liquid outlet, and a cover plate reducing manifold is arranged between the cover plate inlet liquid collecting area and the cover plate outlet liquid collecting area; a concave structure corresponding to the cover plate groove is arranged above the micro-channel cold plate, the micro-channel cold plate comprises a cold plate inlet liquid collecting area and a cold plate outlet liquid collecting area, and micro-channel ribs are arranged between the cold plate inlet liquid collecting area and the cold plate outlet liquid collecting area. The invention provides a novel open type micro-channel radiator structure and a preparation method thereof, and aims at solving the problems that an existing micro-channel radiator is insufficient in heat exchange capacity and poor in flow stability, so that the heat dissipation performance of the novel open type micro-channel radiator structure is remarkably improved. And an innovative solution is provided for design and manufacturing of the micro-channel radiator.

Description

Technical Field

[0001] The invention relates to the field of heat dissipation of electronic devices, and in particular to a novel open microchannel heat sink structure and method. Background Art

[0002] The heat dissipation problem caused by the continuous increase in energy consumption of electronic devices seriously restricts the safe and reliable operation of high-performance computing systems such as servers. Studies have shown that for every 5°C increase in the temperature of electronic components, the reliability of the system will decrease by 25%. Therefore, effective heat dissipation methods and good cooling effects are the basis for ensuring the high reliability and long-term operation of electronic equipment, and they are becoming more urgent and important with the development of electronic equipment. Liquid cooling technology is to exchange heat through the contact between the liquid cooling medium and the heat source, and then the cooling liquid transfers the heat. Liquid has a high heat transfer coefficient, good fluidity and stable working ability, which makes liquid cooling technology the first choice for electronic equipment cooling systems.

[0003] Microchannel liquid cooling has the advantages of high convective heat transfer coefficient, high ultimate heat dissipation density, low thermal resistance, and compact structure. It has great potential in the field of high heat flux density and high heat consumption components. However, in the field of high heat flux density heat dissipation, the traditional closed parallel microchannel liquid cooling plate has weak heat exchange capacity, uneven flow distribution, poor flow stability, and high pressure drop, which poses severe challenges to the heat dissipation of high-performance electronic chips. In addition, the violent boiling of two-phase microchannel heat exchange in a narrow space will cause serious reverse flow and heat transfer degradation, which further hinders performance enhancement. At present, the commercial application of two-phase microchannel radiators is relatively small. Summary of the invention

[0004] The purpose of the present invention is to provide a novel open microchannel heat sink structure and method, which improves the cover structure of the ordinary microchannel heat sink and makes it suitable for heat dissipation of high heat flux density electronic devices. In addition, the heat sink can ensure uniform flow distribution, low pressure drop and minimal flow instability. At the same time, the structure is simple to manufacture and is suitable for batch and customized manufacturing.

[0005] To achieve the above-mentioned purpose, the present invention provides a novel open microchannel radiator structure and method, including a cover plate and a microchannel cold plate, wherein the cover plate is provided with a cover plate liquid inlet and a cover plate liquid outlet, and a groove is provided below the cover plate, the cover plate inlet liquid collection area is located in the groove near the cover plate liquid inlet, the cover plate outlet liquid collection area is located in the groove near the cover plate liquid outlet, and the cover plate tapered manifold is located between the cover plate inlet liquid collection area and the cover plate outlet liquid collection area; a concave structure corresponding to the cover plate groove is provided above the microchannel cold plate, the microchannel cold plate includes a cold plate inlet liquid collection area and a cold plate outlet liquid collection area, and the microchannel rib is located in the middle of the cold plate inlet liquid collection area and the cold plate outlet liquid collection area.

[0006] Preferably, the liquid inlet of the cover plate is connected to the liquid inlet pipe, and the liquid outlet of the cover plate is connected to the liquid outlet pipe.

[0007] Preferably, the cover plate groove is a cooling medium flow area, and the flow cross-sectional area of ​​the cover plate inlet liquid collecting area is larger than the flow area of ​​the cover plate outlet liquid collecting area.

[0008] Preferably, a limiting groove is provided below the microchannel cold plate, and the limiting groove is used for placing heat dissipation components.

[0009] Preferably, four through-shafts are arranged around the microchannel cold plate, and the through-shafts pass through four positioning holes on the microchannel cold plate. Compression nuts are installed at both ends of the through-shafts, and the compression nuts cooperate with the through-shafts to fix the microchannel radiator.

[0010] Preferably, the cover plate tapered manifold includes an inlet open manifold and an outlet open manifold, the inlet open manifold height is H3, the outlet open manifold height is H2, and the microchannel rib height is H1, and the three satisfy the following relationship:

[0011]

[0012] Among them, λ1 and λ2 are adjustment coefficients.

[0013] Preferably, the cover plate and the microchannel cold plate are integrally connected by brazing, the liquid inlet pipe and the cover plate are integrally connected by brazing, and the liquid outlet pipe and the cover plate are integrally connected by brazing. The introduction of manufacturing processes such as brazing enables the new microchannel radiator to use cooling media such as normal pressure and high pressure.

[0014] Preferably, the limiting groove is arranged directly below the microchannel rib, which can effectively determine the optimal heat dissipation position.

[0015] Therefore, the present invention adopts the above-mentioned novel open microchannel radiator structure and method, and the technical effects are as follows:

[0016] 1. The novel open microchannel heat sink described in the present invention uses CNC processing technology to process various components, and copper or aluminum alloy is used as the main manufacturing material. The manufacturing process is simple, the material is easily available, and the production cycle is short. It is suitable for the passage of normal pressure and high pressure cooling media. The manufacturing method of the invention is suitable for the processing and manufacturing of small batch customized products and the mass production of commercial products.

[0017] 2. The novel open microchannel heat sink of the present invention has a greatly improved flow uniformity due to the open manifold on the upper part. In addition, the larger flow cross-sectional area greatly reduces the pressure drop of the microchannel heat sink. It can significantly reduce energy consumption, making it suitable for large-scale server heat dissipation scenarios.

[0018] 3. The novel open microchannel radiator described in the present invention adopts a tapered manifold structure with a large inlet cross-sectional area and a small outlet cross-sectional area, because the critical state of two-phase boiling heat exchange always occurs first at the outlet. The flow rate of the fluid at the outlet is increased, which can effectively delay the occurrence of the two-phase critical state and improve the heat exchange performance. At the same time, the increase in flow rate and the reduction in the cross-sectional area at the outlet can reduce flow instability and temperature distribution unevenness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the decomposition and structural composition of the novel open microchannel heat sink assembly of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the novel open microchannel radiator cover plate of the present invention;

[0021] Figure 3 It is a rear view of a novel open microchannel heat sink microchannel cold plate of the present invention;

[0022] Figure 4 It is an assembly diagram of a novel open microchannel heat sink for improving the heat dissipation capability of electronic devices according to the present invention;

[0023] Figure 5 A cross-sectional view of a novel open microchannel radiator cover structure of the present invention;

[0024] Figure 6 It is a partial enlarged cross-sectional view of the novel open microchannel radiator cover structure of the present invention.

[0025] Reference numerals

[0026] 1. Cover plate; 2. Microchannel cold plate; 3. Liquid inlet pipe; 4. Liquid outlet pipe; 5. Liquid inlet of cover plate; 6. Liquid outlet of cover plate; 7. Liquid collecting area of ​​cover plate inlet; 8. Liquid collecting area of ​​cover plate outlet; 9. Cover plate tapered manifold; 10. Liquid collecting area of ​​cold plate inlet; 11. Liquid collecting area of ​​cold plate outlet; 12. Microchannel rib; 13. Limiting groove; 14. Through shaft; 15. Positioning hole; 16. Press-fit nut; 17. Brazing seam of cover plate inlet and outlet; 18. Brazing seam of cover plate and cold plate. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0028] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0029] Embodiment 1

[0030] like Figure 1-Figure 4 As shown, the purpose of the present invention is to provide a novel open microchannel radiator structure and method, including a cover plate 1 and a microchannel cold plate 2, wherein the cover plate 1 is the main structure for improving the heat dissipation performance of the microchannel cold plate 2. The cover plate 1 is provided with a cover plate liquid inlet 5 and a cover plate liquid outlet 6, wherein the cover plate liquid inlet 5 is connected to the liquid inlet pipe 3 by brazing, and the cover plate liquid outlet 6 is connected to the liquid outlet pipe 4 by brazing, which can ensure good connection strength and is suitable for the entry and exit of normal pressure and high pressure working fluids. The other ends of the liquid inlet pipe 3 and the liquid outlet pipe 4 are standard interfaces to facilitate matching and connection with the inlet and outlet pipes.

[0031] There is a cooling medium circulation area below the cover plate 1. The cover plate inlet liquid collection area 7 is near the cover plate liquid inlet 5 in the area, the cover plate outlet liquid collection area 8 is near the cover plate liquid outlet 6 in the groove, and the cover plate tapered manifold 9 is between the cover plate inlet liquid collection area 7 and the cover plate outlet liquid collection area 8. There is a cooling medium circulation area below the cover plate 1. The flow cross-sectional area of ​​the cover plate inlet liquid collection area 7 is larger than the flow cross-sectional area of ​​the cover plate outlet liquid collection area 8. The presence of the cover plate inlet liquid collection area 7, the cover plate outlet liquid collection area 8, and the cover plate tapered manifold in the cover plate 1 significantly expands the flow cross-sectional area of ​​the cooling medium. Compared with traditional microchannel radiators, it can effectively reduce pressure drop, reduce external pump work, and save costs.

[0032] The microchannel cold plate 2 is provided with a concave structure corresponding to the groove of the cover plate 1. The microchannel cold plate 2 includes a cold plate inlet liquid collection area 10 and a cold plate outlet liquid collection area 11. The microchannel rib 12 is located between the cold plate inlet liquid collection area 10 and the cold plate outlet liquid collection area 11. By adjusting the number of microchannel ribs 12, different heat exchange effects can be achieved. A limiting groove 13 is provided directly below the microchannel rib 12, which can effectively determine the optimal heat dissipation position. The limiting groove 13 is used to place heat dissipation components. The size of the effective heat dissipation area of ​​the microchannel cold plate 2 can be adjusted according to the size of the heat dissipation components, so as to facilitate installation. At the same time, four through shafts 14 are provided around the microchannel cold plate 2. The through shaft 14 passes through four positioning holes 15 on the microchannel cold plate 2. Press-fit nuts 16 are installed at both ends of the through shaft 14. The press-fit nuts 16 cooperate with the through shaft 14 to fix the microchannel cold plate 2.

[0033] The cover plate liquid inlet 5 and the liquid inlet pipe 3, the cover plate liquid outlet 6 and the liquid outlet pipe 4, and the cover plate 1 and the microchannel cold plate 2 are all brazed for integration, forming the cover plate inlet and outlet brazing seams 17 and the cover plate and cold plate brazing seams 18. This brazing structure enables the inside of the microchannel radiator to withstand higher pressures, so that ordinary normal pressure cooling media and high pressure cooling media can be used in the new open microchannel radiator manufactured by the invention. The brazing integrated welding structure improves the applicability of the microchannel radiator. In addition, the components described in the present invention adopt CNC processing technology, with copper or aluminum alloy as the main manufacturing material, and are suitable for commercial mass production.

[0034] like Figure 5-Figure 6 As shown, in order to ensure that the novel open microchannel radiator of the invention has good heat exchange performance, good flow stability and temperature uniformity, the height of the inlet open manifold is H3, the height of the microchannel rib is H1 and the height of the outlet open manifold is H2, and the following relationship should be satisfied between the three:

[0035]

[0036] Among them, λ1 and λ2 are adjustment coefficients. When the value of λ1 is between 0.5 and 0.8 and the value of λ2 is between 0.8 and 1.5, the comprehensive performance of the radiator is better.

[0037] The coolant is introduced into the coolant flow area through the liquid inlet pipe 3, flows from left to right in this area, and gradually reduces the flow cross-sectional area at the leftmost side of the microchannel rib 12. The cover plate tapered manifold 9 on the cover plate 1 ensures that when the coolant flows through this area, the flow velocity of the coolant increases slowly along the flow direction, and the flow velocity reaches the maximum value at the rightmost side of the microchannel rib 12. The coolant absorbs heat in the microchannel and changes from a liquid phase coolant to a gas phase coolant. The tapered manifold structure 9 compresses the gas phase coolant along the flow direction. The gas in the microchannel has a higher flow velocity and a larger expansion volume, which further increases the flow velocity near the outlet. Compared with the traditional open microchannel radiator with a uniform cover plate, the flow velocity of the two-phase fluid near the outlet is greatly increased. Since the critical state of the microchannel radiator always occurs first at the outlet, the increase in flow velocity can significantly enhance the wetting effect of the microchannel surface, delay the appearance of dry spots on the microchannel wall, and thus avoid the critical state from occurring prematurely. Therefore, a novel open microchannel heat sink structure and method proposed in this paper will significantly improve its heat exchange capacity. At the same time, the increase in flow velocity in the cover plate tapered manifold 9 and the reduction in the cross-sectional area at the outlet position can reduce the instability of the two-phase flow. The gradual increase in flow velocity can increase the convective heat transfer coefficient on the microchannel surface, and the heat transfer coefficient continues to increase along the flow direction, avoiding the uneven temperature distribution of the microchannel cold plate 2 along the flow direction.

[0038] Therefore, the present invention adopts the above-mentioned novel open microchannel radiator structure and method to improve the cover plate of the microchannel radiator, thereby solving the disadvantages of the traditional closed parallel microchannel liquid cooling plate, such as low heat flux density, uneven flow distribution, poor flow stability and high pressure drop. In addition, the novel open microchannel radiator described in the present invention has a simple manufacturing process, is easy to obtain materials, and can be commercially produced.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A novel open microchannel heat sink structure and method, characterized in that: It includes a cover plate and a microchannel cold plate, wherein the cover plate is provided with a cover plate liquid inlet and a cover plate liquid outlet, and a groove is provided below the cover plate, the cover plate inlet liquid collection area is located in the groove near the cover plate liquid inlet, the cover plate outlet liquid collection area is located in the groove near the cover plate liquid outlet, and the cover plate tapered manifold is located between the cover plate inlet liquid collection area and the cover plate outlet liquid collection area; a concave structure corresponding to the cover plate groove is provided above the microchannel cold plate, the microchannel cold plate includes a cold plate inlet liquid collection area and a cold plate outlet liquid collection area, and the microchannel rib is located in the middle between the cold plate inlet liquid collection area and the cold plate outlet liquid collection area.

2. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: The liquid inlet of the cover plate is connected to the liquid inlet pipe, and the liquid outlet of the cover plate is connected to the liquid outlet pipe.

3. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: The cover plate groove is a cooling medium flow area, and the flow cross-sectional area of ​​the cover plate inlet liquid collecting area is greater than the flow area of ​​the cover plate outlet liquid collecting area.

4. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: A limiting groove is provided below the microchannel cold plate, and the limiting groove is used for placing heat dissipation components.

5. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: Four through-shafts are arranged around the microchannel cold plate, and compression nuts are installed at both ends of the through-shafts. The compression nuts cooperate with the through-shafts to fix the microchannel radiator.

6. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: The cover plate tapered manifold includes an inlet open manifold and an outlet open manifold, the inlet open manifold height is H3, the outlet open manifold height is H2, and the microchannel rib height is H1, and the three satisfy the following relationship: Among them, λ1 and λ2 are adjustment coefficients.

7. A novel open microchannel heat sink structure and method according to claim 1, characterized in that: The cover plate and the microchannel cold plate are integrally connected by brazing, the liquid inlet pipe and the cover plate are integrally connected by brazing, and the liquid outlet pipe and the cover plate are integrally connected by brazing.

8. A novel open microchannel heat sink structure and method according to claim 4, characterized in that: The limiting groove is arranged directly below the microchannel rib.

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