Efficient liquid cooling universal flow channel and design method thereof

Abstract

The invention discloses an efficient liquid cooling universal flow channel and a design method thereof, a flow channel is used as a flow channel design main body, a welding safety column is arranged at a position corresponding to a mounting hole in the flow channel to separate the flow channel from the mounting hole, and the flow channel outside the welding safety column is fully utilized to arrange a turbulent flow column; a conventional channel, a small channel and a turbulent flow column are designed in a narrow space between welding safety columns, and the conventional channel or the small channel is used in a place with fewer mounting holes, so that the design problem of a cold plate flow channel that a flow channel distribution space under an electronic device hot spot is extremely narrow and even has no distribution space is solved; and the liquid-cooling heat dissipation requirements of electronic devices with multiple electronic device hot spots and concentrated mounting holes around the hot spots can be well met. The heat exchanger is high in heat exchange capacity and high in universality.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic device cooling, and particularly relates to an efficient liquid-cooled common flow channel and its design method. Background Art

[0002] With the rapid development of electronic technology, the heat load of electronic devices and the heat flux density of their chips are getting higher and higher, and the thermal design of electronic devices faces severe challenges. Research shows that when the operating temperature of the CPU exceeds the rated temperature by 10°C, the reliability is reduced by 50%; the high heat flux density will form "hot spots" on the installation surface of the electronic device, significantly increasing the junction temperature of the device chip, resulting in performance degradation and reduced reliability, and the thermal stress generated by high temperature is more likely to directly damage the device.

[0003] Liquid media have a high heat transfer coefficient and large specific heat capacity, and have a strong cooling capacity. The liquid-cooled cold plate can give full play to the cooling capacity of the liquid medium, and has the advantages of reasonable temperature rise, good temperature uniformity, mature technology, convenient installation of electronic devices, and compact structure, effectively solving the heat dissipation problem of high-power consumption and high heat flux density electronic devices. At present, the flow channels of liquid-cooled cold plates mostly adopt forms such as conventional channels, small channels, and turbulators, and are welded into shape by vacuum brazing or diffusion welding. Considering the welding reliability, when designing, a certain safety margin is left for the distance from the internal flow channel of the cold plate to the outside or to the hole edge to prevent the cold plate from leaking due to insufficient welding rate.

[0004] With the increasing miniaturization, high power, and environmental adaptability requirements of electronic devices, electronic devices are constantly evolving towards high-density assembly and integrated packaging, and the heat consumption and the number of hot spots of electronic devices are increasing. The number of mounting holes for fastening has increased sharply. The increase in the number of mounting holes can ensure the close fit between the electronic device and the cold plate, thereby effectively reducing the contact thermal resistance between the two. However, because the flow channel of the liquid-cooled cold plate needs to avoid the mounting holes, the increase in the number of mounting holes brings great trouble to the flow channel design. In addition, the mounting holes are mostly concentrated around the hot spots with high heat consumption and high heat flux density. Especially when electronic devices are installed on both the front and back sides of the cold plate, the available space for arranging the flow channel in the concentrated area of the hot spots and mounting holes is extremely small or even non-existent, which undoubtedly increases the difficulty of the flow channel design and even makes the cold plate unable to meet the heat dissipation requirements of the electronic device, and the liquid-cooled flow channel design faces new challenges.

[0005] In the prior art, the influence of the mounting holes is basically not considered or has little influence in the flow channel design, and there is sufficient space under the hot spot to arrange various forms of flow channels, but such flow channels are difficult to apply to the situation where there are many hot spots and the mounting holes are concentrated around the hot spots. Summary of the Invention

[0006] The purpose of the present invention is to provide an efficient liquid-cooled common flow channel.

[0007] The technical solution for achieving the purpose of the present invention is as follows: An efficient liquid cooling general flow channel is provided in a cold plate installed with electronic devices. The flow channel is provided around or directly below hot spots where the number of hot spots is greater than the number threshold, or the heat flux density of the hot spots is higher than the set threshold, or the installation hole density is higher than the density threshold. Welding safety columns are arranged at positions corresponding to the installation holes in the flow channel. The welding safety columns are used to separate the flow channel from the installation holes, and turbulence columns are arranged in the area outside the welding safety columns in the flow channel.

[0008] Preferably, the welding safety column is a cylinder with the center of the installation hole on the cold plate as the center of the circle and the safe distance to the flow channel wall or to the installation hole as the radius.

[0009] Preferably, the safe distance is 6 - 8 mm.

[0010] Preferably, the flow channel is a rhombic column or a circular column flow channel.

[0011] Preferably, when the distance between adjacent welding safety columns is less than the set threshold, the flow channel connecting the adjacent welding safety columns is a small channel, and when the distance between adjacent welding safety columns is less than the set threshold, the flow channel connecting the adjacent welding safety columns is a conventional channel.

[0012] A design method for an efficient liquid cooling general flow channel, in which a flow channel is arranged in a cold plate installed with electronic devices. The flow channel is arranged around or directly below hot spots where the number of hot spots is greater than the number threshold, or the heat flux density of the hot spots is higher than the set threshold, or the installation hole density is higher than the density threshold;

[0013] Welding safety columns are arranged at positions corresponding to the installation holes in the flow channel. The welding safety columns are used to separate the flow channel from the installation holes;

[0014] Turbulence columns are arranged in the area outside the welding safety columns in the flow channel.

[0015] Compared with the prior art, the present invention has the following remarkable advantages:

[0016] 1) Strong adaptability: The flow channel uses welding safety columns to separate the flow channel from the installation holes, makes full use of the space outside the welding safety columns to design turbulence columns, and cooperates with the use of conventional channels and small channels to achieve efficient utilization of space to improve the heat exchange capacity of the liquid cooling flow channel, and is well adapted to the situation of many hot spots and many installation holes.

[0017] 2) High reliability: While isolating the installation holes, the welding safety columns provide support for the cold plate flow channel, improve the overall welding effect of the flow channel, and avoid poor welding or virtual soldering and liquid leakage during post-welding processing of the installation holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the liquid cooling flow channel structure of Embodiment 1 of the present invention.

[0019] Figure 2It is a schematic diagram of the hot spot and cold plate simulation boundary conditions of the electronic device in Embodiment 1 of the present invention.

[0020] Figure 3 It is the simulation result of the cold plate in Embodiment 1 of the present invention - temperature nephograms of the front and back sides.

[0021] Figure 4 It is the simulation result of the cold plate in Embodiment 1 of the present invention - flow trace diagram.

[0022] Figure 5 It is the liquid cooling channel structure in Embodiment 2 of the present invention.

[0023] Figure 6 It is a schematic diagram of the hot spot and cold plate simulation boundary conditions of the electronic device in Embodiment 2 of the present invention.

[0024] Figure 7 It is the simulation result of the cold plate in Embodiment 2 of the present invention - temperature nephograms of the front and back sides.

[0025] Figure 8 It is the simulation result of the cold plate in Embodiment 2 of the present invention - flow trace diagram.

[0026] Wherein:

[0027] 1 - cold plate, 2 - hot spot of the electronic device, 3 - mounting hole, 4 - conventional channel, 5 - small channel, 6 - flow channel, 7 - welding safety post; 6 - 1 - turbulator post. Detailed implementation manners

[0028] The efficient liquid cooling general flow channel design method proposed by the present invention takes the flow channel as the design main body. By setting welding safety posts at the positions corresponding to the mounting holes in the flow channel to separate the flow channel from the mounting holes, the space outside the welding safety posts is fully utilized to arrange turbulator posts, and conventional channels, small channels, and turbulator post sub-channels are designed in the narrow space between the welding safety posts. Conventional channels or small channels are used in places where there are fewer mounting holes, solving the cold plate flow channel design problem that the available space for the flow channel directly below the hot spot of the electronic device is extremely narrow or even there is no available space, and well adapting to the liquid cooling heat dissipation requirements of electronic devices with multiple hot spots of electronic devices and concentrated mounting holes around the hot spots.

[0029] The following takes embodiments in conjunction with the accompanying drawings and describes the present invention in detail.

[0030] An efficient liquid cooling general flow channel, when designing, takes the flow channel as the main body of the flow channel, sets welding safety posts in the flow channel to separate the flow channel from the mounting holes, fully utilizes the space outside the welding safety posts to arrange turbulator posts, designs conventional channels, small channels, and turbulator posts in the narrow space between the welding safety posts, and uses conventional channels or small channels in places where there are fewer mounting holes, which can well solve the cold plate flow channel design problem that the available space for the flow channel directly below the hot spot of the electronic device is extremely narrow or even there is no available space.

[0031] The cold plate is the support main body and heat dissipation carrier of electronic devices, and plays the role of fixing and cooling electronic devices.

[0032] The hot spot of an electronic device is the projection area of the heat-generating element or chip inside the electronic device on the device housing, and the magnitude and distribution position of its heat dissipation are the basis for the design of the cold plate flow channel.

[0033] Furthermore, the conventional channel is a rectangular cross-section flow channel with a hydraulic diameter > 3 mm, and is used for areas with few hot spots or low hot spot heat flux density.

[0034] Furthermore, the small channel is a rectangular cross-section flow channel with a hydraulic diameter of 200 μm to 3 mm, which improves the heat transfer coefficient and increases the heat transfer area, and is used for areas with more hot spots, high hot spot heat flux density, fewer mounting holes or a long distance from hot spots.

[0035] Furthermore, the flow channel is a rhombic column or circular column flow channel, which increases the disturbance, further improves the heat transfer coefficient and increases the heat transfer area, and has flexible layout, and is used for areas with many hot spots, high hot spot heat flux density, and mounting holes concentrated around or directly below the hot spots.

[0036] Furthermore, the welding safety columns are distributed in the flow channel, and are cylinders with the center of the mounting hole on the cold plate as the center of the circle and the safety distance to the edge or to the hole as the radius, ensuring that the minimum distance (welding safety distance) from the flow channel to the outside meets the requirements of the welding process.

[0037] Furthermore, the inscribed diameter or diameter of the rhombic or circular turbulator columns in the flow channel is generally 1 to 5 mm.

[0038] Furthermore, the radius of the welding safety column is the radius of the mounting hole + the welding safety distance, and the welding safety distance is generally taken as 6 to 8 mm.

[0039] Furthermore, according to the center distance of the mounting holes in the flow channel, the welding safety columns in the flow channel are either connected in one piece, or a conventional channel is set, or a small channel is set, or turbulator columns are set.

[0040] Furthermore, the conventional channel is easy to process, has a small flow resistance, and weak heat transfer ability; the small channel and the flow channel are more difficult to process, have a large flow resistance, and strong heat transfer ability; the three cooperate with each other and complement each other, while meeting the heat dissipation requirements, controlling the processing cost and total flow resistance of the cold plate.

[0041] Such as Figure 1 、 2 As shown in 5 and 6, it is the liquid cooling flow channel structure and boundary conditions of the cold plate (1) with electronic devices mounted on both the front and back sides.

[0042] The front - side electronic devices of the cold plate (1) in Embodiment 1 are different from those of the cold plate (1) in Embodiment 2, but the hot spots (2) of the electronic devices in both are scattered over the entire surface; the back - side electronic devices and their hot spots (2) are in the same state, concentrated in a corner of the surface. In the overlapping area of the hot spots (2) of the front - and back - side electronic devices on the cold plate (1), there are many hot spots (2), the mounting holes (3) are concentrated and mostly distributed directly below the hot spots (2). Considering the welding safety distance from the flow channel to the edge or hole, the available space for arranging the flow channel between the mounting holes (3) in this overlapping area is extremely narrow or even there is no available space.

[0043] In response to this, when designing the liquid - cooling flow channel, flow channels (6) are set in the area where there are many hot spots (2) and the mounting holes (3) are concentrated: Welding safety columns (7) are used to isolate the mounting holes (3) in the flow channel (6) to ensure reliable welding of the cold plate (1) and no liquid leakage; turbulators (6 - 1) are arranged in the flow channel (6) outside the welding safety columns (7) to ensure the heat - transfer coefficient and heat - transfer area; Conventional channels (4), small channels (5), and turbulators (6 - 1) are designed in the narrow space between the welding safety columns (7) to avoid forming flow dead zones in the flow channel (6) and ensure reasonable fluid diversion according to the distribution of the hot spots (2) of the electronic devices and efficient heat transfer. In the area where there are fewer hot spots (2), fewer or scattered mounting holes (3), conventional channels (4) or small channels (5) are set to meet the heat - dissipation requirements of this area and reduce the overall flow resistance of the flow channel.

[0044] Furthermore, as Figure 1 、 5 shown, the minimum diameter of the welding safety column (7) is 17 mm. If the mounting hole (3) is an M3 threaded hole, then the welding safety distance is 7 mm, which well meets the requirements of the welding process.

[0045] As Figure 2 、 3 、4, 6, 7, 8 shown, they are the CFD (Computational Fluid Dynamics) simulation boundary conditions and simulation results of the liquid - cooling flow channel. The total heat dissipation of the hot spots (2) of the electronic devices of the cold plate (1) in Embodiment 1 is 2130 W, and the total heat dissipation of the hot spots (2) of the electronic devices of the cold plate (1) in Embodiment 2 is 1506 W; The simulation boundary conditions of Embodiments 1 and 2 are the same: The inlet volume flow rate of the cold plate (1) is 4 L / min, the cooling medium is 65# aviation coolant, the coolant inlet temperature is 40 °C, the outlet static pressure is 101325 Pa, the working environment temperature of the cold plate (1) is 55 °C, and the material of the cold plate (1) is aluminum 6063; It is required that the maximum temperature of the cold plate (1) ≤ 75 °C and the flow resistance ≤ 1 bar.

[0046] According to the simulation results: 1) In Example 1, the coolant inlet temperature is 40°C and the coolant outlet temperature is 49.3°C; in Example 2, the coolant inlet temperature is 40°C and the coolant outlet temperature is 46.6°C. There is no flow dead zone in the flow channel (6) and the temperature rise is reasonable, indicating that the coolant flow distribution is reasonable under this flow channel design, and its heat-carrying capacity can be fully exerted. 2) The surface temperature of the cold plate (1) in Example 1 is less than 70.4°C and the flow resistance is 0.35 bar, meeting the design requirements; the surface temperature of the cold plate (1) in Example 2 is less than 66.4°C and the flow resistance is 0.32 bar, meeting the design requirements.

[0047] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-efficiency liquid cooling universal flow channel, characterized in that: A flow channel (6) is provided in a cold plate on which an electronic device is installed. The flow channel is provided around or directly below a hot spot where the number of hot spots (2) is greater than a number threshold, the heat flux density of the hot spots (2) is greater than a set threshold, or the density of the mounting holes (3) is greater than a density threshold. A welding safety column (7) is provided at a position corresponding to the mounting hole (3) in the flow channel (6). The welding safety column (7) is used to separate the flow channel from the mounting hole (3). A spoiler column (6-1) is provided in an area outside the welding safety column (7) in the flow channel (6).

2. The high-efficiency liquid cooling universal flow channel according to claim 1, characterized in that: The welding safety column (7) is a cylinder with the center of the mounting hole (3) on the cold plate (1) as the center of the circle and the safety distance to the flow channel wall or to the mounting hole (3) as the radius.

3. The high-efficiency liquid cooling universal flow channel according to claim 2, characterized in that: The safety distance is 6 to 8 mm.

4. The high-efficiency liquid cooling universal flow channel according to claim 2, characterized in that: The flow channel (6) is a diamond column or a circular column flow channel.

5. The high-efficiency liquid cooling universal flow channel according to claim 2, characterized in that: When the distance between adjacent welding safety columns (7) is less than a set threshold, the flow channel (6) connecting the adjacent welding safety columns (7) is a small channel; when the distance between adjacent welding safety columns (7) is less than a set threshold, the flow channel (6) connecting the adjacent welding safety columns (7) is a regular channel.

6. A method for designing a high-efficiency liquid cooling universal flow channel according to any one of claims 1 to 5, characterized in that: A flow channel (6) is arranged in a cold plate on which electronic devices are installed, wherein the flow channel is arranged around or directly below a hot spot where the number of hot spots (2) is greater than a number threshold, the heat flux density of the hot spots (2) is higher than a set threshold, or the density of the mounting holes (3) is higher than a density threshold; A welding safety column (7) is arranged at a position corresponding to the mounting hole (3) in the flow channel (6), wherein the welding safety column (7) is used to separate the flow channel from the mounting hole (3); A spoiler column (6-1) is arranged in the area outside the welded safety column (7) in the flow channel (6).

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