An immersion-type high-power chip boiling enhanced heat dissipation system

Abstract

This utility model discloses an immersion-type high-power chip boiling-enhanced heat dissipation system, relating to the field of electronic device heat dissipation technology. It includes a high-power chip and a mesh-like perforated plate; the surface of the high-power chip is provided with heat-enhancing microstructures; the mesh-like perforated plate is arranged parallel to the outer side of the surface of the high-power chip with the heat-enhancing microstructures, and the distance between the mesh-like perforated plate and the surface is 0.2mm-2mm; the equivalent pore size of the mesh-like perforated plate is 0.3mm-1mm. This utility model significantly enhances the safety of immersion phase change cooling and improves the heat dissipation limit.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation technology for electronic devices, and more specifically to an immersion-type high-power chip boiling enhanced heat dissipation system. Background Technology

[0002] Cooling technology in computing centers (such as data centers and supercomputing centers) is crucial for ensuring stable equipment operation, improving energy efficiency, and reducing operating costs. With the explosive growth in computing power demand (such as AI, cloud computing, and edge computing), the cooling challenges posed by high-density computing equipment are becoming increasingly severe. Traditional cooling technologies are no longer sufficient, and the industry is accelerating its evolution towards efficient, green, and intelligent cooling solutions. The following is an analysis of the current status of mainstream and cutting-edge cooling technologies: 1. Traditional air-cooling technology: Widely used, it remains a standard feature in small and medium-sized data centers, suitable for low power density scenarios (<10kW / rack). However, it suffers from energy efficiency bottlenecks: PUE (Power Usage Effectiveness) is typically above 1.5, and cooling energy consumption accounts for 30%~40% of total energy consumption. 2. Liquid cooling technology (core trend): Liquid cooling technology, which uses liquid to directly or indirectly contact the heat source, is over 1000 times more efficient than air cooling and has become the mainstream choice for high-density computing centers (such as GPU clusters and AI servers). It is mainly divided into indirect liquid cooling and immersion cooling. Cold plate liquid cooling (indirect liquid cooling): Principle: Liquid flows through a metal cold plate in contact with the chip, carrying away heat, and then dissipates heat through external circulation. Its advantages include compatibility with existing server architectures, low modification costs, and a PUE that can be reduced to 1.1-1.2. Disadvantages include the complexity of current liquid cooling piping designs, making them prone to leakage and condensation, which somewhat limits the stability and reliability of server equipment operation. Additionally, it requires energy consumption when the outside air temperature is high.

[0003] Immersion liquid cooling (direct liquid cooling): Principle: The server is completely immersed in an insulating cooling medium (such as mineral oil or fluorinated liquid). The medium transfers heat from the heat-generating components to a natural cold source for cooling via single-phase heat exchange or phase-change heat exchange, and then circulates the heat back to the heat-generating components. Single-phase heat exchange has poor cooling capacity and a large temperature difference, requiring active cooling except in low-temperature regions and seasons. In contrast, phase-change cooling with media such as fluorinated liquids offers extremely high heat dissipation efficiency. The medium vapor can be completely cooled by air, eliminating the need for active cooling. It supports power densities of 100kW / rack and above, achieving a PUE as low as 1.02-1.05.

[0004] However, the safety of immersion cooling largely depends on the critical heat flux density during the boiling heat transfer process of the medium. The existence of the boiling critical heat flux density limits the maximum heat flux density for heat dissipation. Conventional immersion cooling directly exposes the heat-generating chip to the fluorinated liquid. Under the most unfavorable summer natural cooling conditions (air cooling or liquid cooling tower), the temperature of the refluxed fluorinated liquid is close to the saturation temperature at atmospheric pressure. At this point, the critical heat flux density for boiling in the saturated pool of the fluorinated liquid is 20-30 W / cm³. 2 That is, when the heat flux density of a heat-generating chip (such as a CPU, GPU, etc.) exceeds 30W / cm³ 2 In such cases, the chip will burn out directly, and many high-power chips can achieve a heat flux density of 50 W / cm². 2 Therefore, phase change cooling without enhancing the critical heat flux density is dangerous and does not meet the heat dissipation requirements of current mainstream chips. Consequently, conventional immersion cooling requires forced convection and cryogenic cooling of the fluorinated liquid to achieve the desired heat dissipation effect, which significantly increases additional energy consumption, cooling power consumption, and pump consumption.

[0005] Therefore, for immersion phase change cooling systems for chips, it is of great significance to improve the immersion cooling heat dissipation structure, overcome the heat dissipation bottleneck caused by critical heat flux density, and thus improve cooling efficiency and reduce cooling energy consumption.

[0006] The efficient heat transfer mechanism of boiling lies in the formation of an extremely thin micro-liquid film at the bottom (boiling surface) of bubbles during the initial boiling process. Evaporation heat transfer through this micro-liquid film is the primary heat transfer mechanism responsible for the extremely high heat flux density of boiling. In the initial boiling and nucleation boiling development regions, bubble growth is relatively slow, the initial thickness of the micro-liquid film is thicker, and the bubble density is relatively low. Therefore, appropriately inhibiting rapid bubble detachment and increasing the evaporation area and time of the micro-liquid film can significantly enhance heat transfer. However, near the critical heat load region, if the wall dries out after the micro-liquid film evaporates, the bubbles cannot detach in time, and the wall drying will continue, leading to deterioration of heat transfer.

[0007] Therefore, proposing an immersion-type high-power chip boiling enhanced heat dissipation system to solve the difficulties of the existing technology is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] In view of this, the present invention provides an immersion-type high-power chip boiling enhanced heat dissipation system to solve the technical problems existing in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: An immersion-type high-power chip boiling enhanced heat dissipation system includes a high-power chip and a mesh porous plate; the surface of the high-power chip is provided with heat transfer enhanced microstructures; the mesh porous plate is arranged parallel to the outer side of the surface of the high-power chip with heat transfer enhanced microstructures, and the distance between the mesh porous plate and the surface is 0.2mm-2mm; the equivalent pore size of the mesh porous plate is 0.3mm-1mm.

[0010] Optionally, the heat transfer-enhancing microstructure can be a periodically arranged array of microgrooves, microfins, or micropits.

[0011] Optionally, the microgroove has a rectangular cross-section, with a groove depth of 30μm-200μm and a groove width of 50μm-300μm.

[0012] Optionally, the perforated mesh plate can be made of woven metal wire mesh, laser-perforated metal plate, or electroformed perforated plate.

[0013] Optionally, the thickness of the mesh porous plate is 0.1mm-0.5mm, and the porosity is 40%-80%.

[0014] Optionally, it also includes spacer pillars or support frames made of insulating material, with the mesh perforated plate fixed to the chip package or heat sink via the spacer pillars or support frames.

[0015] Optionally, the high-power chip can be a CPU, GPU, or AI acceleration chip.

[0016] Optionally, it also includes a sealed immersion liquid cooling tank, in which multiple high-power chips and corresponding mesh perforated plates are arranged vertically side by side.

[0017] Optionally, when the phase change working fluid is a fluorinated liquid, the equivalent pore size of the corresponding mesh porous plate is 0.3mm-0.8mm.

[0018] Optionally, when the phase change working medium is ultrapure water, the equivalent pore size of the corresponding mesh porous plate is 0.8mm-1.2mm.

[0019] As can be seen from the above technical solution, compared with the prior art, this utility model discloses an immersion-type high-power chip boiling enhanced heat dissipation system, the beneficial effects of which are: 1) Fundamentally improve heat dissipation capacity and safety: Break through the critical heat flux (CHF) bottleneck The most significant effect of this invention is that it greatly increases the boiling critical heat flux (CHF) on the chip surface. In traditional immersion boiling, when the heat flux reaches CHF (such as about 20-30 W / cm² in fluorinated liquids), the liquid film dries up rapidly, causing the chip to overheat and burn out. By precisely controlling the bubble behavior through a mesh porous plate, the vicious cycle of "bubble coverage - liquid film drying" can be effectively delayed and suppressed. Experiments show that the CHF of the chip using this structure in atmospheric pressure fluorinated liquid can be increased to more than 50 W / cm², and even reach 100-150 W / cm². This allows it to safely and efficiently meet the heat dissipation requirements of current and future high-power chips (such as GPUs with heat flux exceeding 50 W / cm²), fundamentally removing the application limitations of immersion phase change cooling in high-temperature environments. 2) Achieve efficient heat transfer enhancement across the entire boiling range: balancing nucleation boiling and the critical region. The enhancement effect of this invention covers the entire process from initial boiling to the critical point: In the low heat flux nucleo-boiling region, the mesh plate's temporary suppression of initial small bubbles forces the formation and maintenance of a larger, extremely thin micro-liquid film at the bottom of the bubbles. Due to the extremely high evaporative heat transfer efficiency of the micro-liquid film, this directly leads to a significant increase in the boiling heat transfer coefficient (HTC) in the early stages, allowing the chip to dissipate the same amount of heat at lower superheat. In the high heat flux region near the critical point, the open structure of the mesh plate ensures that fully developed large bubbles can penetrate and detach in a timely manner, avoiding premature drying caused by bubble retention on traditional enhanced surfaces. Simultaneously, the rapid detachment of large bubbles can violently disturb the boundary layer, resulting in a strong forced convection effect, further enhancing heat dissipation. This synergistic mechanism of "promoting evaporation in the early stage and promoting convection in the later stage" achieves performance optimization under all operating conditions. 3) Optimize system energy efficiency and reliability: Moving towards "zero" cooling energy consumption and reducing / eliminating active cooling requirements: Due to the significant improvement in CHF, the immersion liquid cooling system allows the condensate reflux working fluid temperature to be closer to or even reach the saturation temperature at ambient temperature without worrying about chip overheating. This enables the system to rely entirely on natural cold sources such as dry coolers or cooling towers for heat dissipation in a wider range of climatic conditions (including hot summers), reducing the system PUE (Power Usage Effectiveness) to below 1.05, approaching the ideal value of 1.02, and greatly reducing the cooling energy consumption of the data center; Improve system reliability: The mesh porous plate acts as a physical barrier, which can suppress the working fluid splashing or localized severe pressure fluctuations that may be caused by violent boiling to a certain extent, which is conducive to the long-term stable operation of the system; In addition, the non-bonded installation method avoids stress problems caused by the mismatch of material thermal expansion coefficients, making the structure more reliable. 4) Offers high design flexibility and process feasibility: The parameters are adjustable and widely adaptable. By adjusting the three core design parameters of "spacing-aperture-microstructure", this structure can flexibly adapt to the heat dissipation requirements of different working fluids (such as fluorinated liquids and water), different chip heat flux densities, and different packaging forms, making it highly versatile. The process is simple and easy to integrate. The mesh porous plate can be manufactured using mature weaving, stamping, or laser processing technologies and fixed by simple mechanical means. It does not require complex micro-bonding or coating with the chip surface, which reduces manufacturing costs and process difficulty, making it easy to integrate and implement in existing immersion liquid-cooled server designs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 A structural diagram of an immersion-type high-power chip boiling enhanced heat dissipation system provided by this utility model; Figure 2 A plan view of the mesh perforated plate provided by this utility model; Among them, 1-mesh porous plate, 2-enhanced heat transfer microstructure, 3-high-power chip. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] This utility model discloses an immersion-type high-power chip boiling-enhanced heat dissipation system. A mesh-like perforated plate 1 is arranged parallel to the chip at a certain distance. When boiling bubbles are generated and grow, the size of bubbles in the initial boiling and incomplete development stages of the fluorinated liquid before detachment is generally greater than 0.5 mm, while the size of fully developed boiling individual bubbles is generally less than 0.5 mm. However, adjacent individual bubbles merge during the middle growth stage, and the size of the merged bubble is greater than 1 mm. Therefore, on the one hand, the perforated plate or mesh with a suitable aperture suppresses the initial growth of bubbles. Due to the slow initial growth rate, the internal pressure of the bubble cannot overcome the tension formed by the holes in the perforated plate or mesh, causing the bubble to expand along the chip plane. This increases the evaporation area of ​​the micro-liquid film generated at the bottom, greatly enhancing phase change heat transfer. On the other hand, when the bubbles grow larger and two or more bubbles merge, heat exchange evaporation causes the bubbles to grow rapidly and easily penetrate the surface tension formed by the mesh, forming large bubbles. The strong convection triggered by the detachment of these large bubbles greatly enhances the convective heat transfer on the chip surface.

[0024] Thus, the two effects mentioned above—namely, suppressing the initial growth process of bubbles and expanding the evaporation area between the bubbles and the heat transfer interface, while not affecting the later detachment of bubbles and preventing the drying of the liquid film between the bubbles and the heat transfer surface—significantly increase the heat transfer coefficient and critical heat flux density from initial boiling to fully developed boiling.

[0025] See Figure 1 As shown in the figure, this utility model embodiment discloses an immersion-type high-power chip boiling enhanced heat dissipation system, including a high-power chip 3 and a mesh porous plate 1; the surface of the high-power chip 3 is provided with a heat transfer enhanced microstructure 2; the mesh porous plate 1 is arranged parallel to the outer side of the surface of the high-power chip 3 with the heat transfer enhanced microstructure 2, and the distance between the mesh porous plate 1 and the surface is 0.2mm-2mm; the equivalent pore diameter of the mesh porous plate 1 is 0.3mm-1mm.

[0026] Furthermore, the enhanced heat transfer microstructure 2 is an array of periodically arranged microgrooves, microfins, or micropits.

[0027] Furthermore, the microgrooves have a rectangular cross-section, with a groove depth of 30μm-200μm and a groove width of 50μm-300μm.

[0028] Furthermore, the mesh perforated plate 1 is a woven metal wire mesh, a laser-perforated metal plate, or an electroformed perforated plate.

[0029] Furthermore, the thickness of the mesh porous plate 1 is 0.1mm-0.5mm, and the porosity is 40%-80%.

[0030] For details, see Figure 2 The figure shown is a plan view of the mesh porous plate 1.

[0031] Furthermore, it also includes spacer pillars or support frames made of insulating material, and the mesh porous plate 1 is fixed to the chip package or heat dissipation base by the spacer pillars or support frames.

[0032] Furthermore, the high-power chip 3 is a CPU, GPU, or AI acceleration chip.

[0033] Furthermore, it also includes a sealed immersion liquid cooling tank, in which multiple high-power chips 3 and corresponding mesh perforated plates 1 are arranged vertically side by side.

[0034] Furthermore, when the phase change working fluid is a fluorinated liquid, the equivalent pore size of the corresponding mesh porous plate 1 is 0.3 mm to 0.8 mm.

[0035] Furthermore, when the phase change working fluid is ultrapure water, the equivalent pore size of the corresponding mesh porous plate 1 is 0.8 mm-1.2 mm.

[0036] Specifically, this invention aims to address the heat dissipation failure of high-heat-flux chips caused by the limitation of critical heat flux density in existing immersion boiling cooling systems. The core of this approach lies in placing a mesh-like porous plate 1 with a specific micro-pitch (0.2mm~2mm) parallel to the outer surface of the high-power chip 3, which has a heat-enhancing microstructure 2. The equivalent pore size (0.3mm~1mm) of the mesh-like porous plate 1 is specially designed to temporarily suppress bubble detachment through surface tension during the initial boiling stage, forcing bubbles to expand along the chip surface and significantly increasing the area of ​​the efficient evaporation micro-liquid film. After full boiling development, it allows combined bubbles to penetrate and detach smoothly, preventing the liquid film from drying out and inducing strong convection. This staged and precise control of bubble growth and detachment behavior, in conjunction with the microstructure of the chip surface, achieves a significant improvement in the heat transfer coefficient and critical heat flux density throughout the entire process from initial boiling to the critical point, significantly enhancing the safety and heat dissipation limit of immersion phase change cooling.

[0037] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An immersion-type high-power chip boiling-enhanced heat dissipation system, characterized in that, It includes a high-power chip and a mesh porous plate; the surface of the high-power chip is provided with heat transfer enhanced microstructures; the mesh porous plate is arranged parallel to the outer side of the surface of the high-power chip with heat transfer enhanced microstructures, and the distance between the mesh porous plate and the surface is 0.2mm-2mm; the equivalent pore size of the mesh porous plate is 0.3mm-1mm.

2. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, The heat transfer enhanced microstructures are periodically arranged arrays of microgrooves, microfins, or micropits.

3. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 2, characterized in that, The microgrooves have a rectangular cross-section, with a groove depth of 30μm-200μm and a groove width of 50μm-300μm.

4. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, The mesh perforated plate is made of woven metal wire mesh, laser-perforated metal plate, or electroformed perforated plate.

5. An immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1 or 4, characterized in that, The thickness of the mesh porous plate is 0.1mm-0.5mm, and the porosity is 40%-80%.

6. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, It also includes spacer pillars or support frames made of insulating material, and the mesh perforated plate is fixed to the chip package or heat sink base by the spacer pillars or support frames.

7. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, High-power chips are CPUs, GPUs, or AI acceleration chips.

8. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, It also includes a sealed immersion liquid cooling tank, in which multiple high-power chips and corresponding mesh perforated plates are arranged vertically side by side.

9. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, When the phase change working fluid is a fluorinated liquid, the equivalent pore size of the corresponding mesh porous plate is 0.3mm-0.8mm.

10. The immersion-type high-power chip boiling-enhanced heat dissipation system according to claim 1, characterized in that, When the phase change working medium is ultrapure water, the equivalent pore size of the corresponding mesh porous plate is 0.8mm-1.2mm.

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