Efficient heat dissipation device based on non-Newtonian fluid and metal fins and preparation method of efficient heat dissipation device

Abstract

The invention discloses an efficient heat dissipation device based on non-Newtonian fluid and metal fins and a preparation method thereof.The efficient heat dissipation device comprises a sealing cover, a base and the porous metal fins, the sealing cover is internally provided with a containing cavity matched with the porous metal fins, the porous metal fins are arranged on the base, and the containing cavity is communicated with the base. The sealing cover covers the base, so that the sealing cover and the base form a sealed cavity structure, a working medium inlet and a working medium outlet are respectively formed in the sealing cover and are connected with an external liquid cooling circulation system, and a cooling working medium is a non-Newtonian fluid; according to the scheme, the non-Newtonian fluid is coupled with the porous fin structure, and the local viscosity of a working medium is actively regulated and controlled by utilizing a high shear field in the porous medium, so that the synergistic strengthening effect of low pump work and high heat exchange is realized.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic devices, and in particular to a high-efficiency heat dissipation device based on non-Newtonian fluid and metal fins and its preparation method. Background Technology

[0002] With the rapid increase in computing power of electronic devices, the heat flux density of their internal chips has increased dramatically. Insufficient heat dissipation capacity has become a key bottleneck restricting further improvements in device performance and reliability. Traditional air cooling technology is limited by the low heat capacity and low thermal conductivity of air, and its heat dissipation performance is approaching its physical limits, making it difficult to meet the needs of high heat flux density scenarios. Liquid cooling technology, especially cold plate liquid cooling, has shown superior heat dissipation potential compared to air cooling due to the higher heat capacity of the cooling medium, becoming an important direction for dealing with high heat loads. However, existing liquid cooling systems mostly use fluids such as water or ethylene glycol as cooling media, and the heat transfer performance of these fluids in laminar flow is also limited. To enhance heat exchange, the system often needs to increase pump power to increase flow rate, but this directly leads to increased system energy consumption and may cause problems such as vibration and noise, which to some extent weakens the advantages of liquid cooling technology.

[0003] Existing technologies have also seen various improvements aimed at enhancing heat dissipation efficiency. For example, some inventions optimize the liquid cooling channel design by incorporating channels with different cross-sectional areas within the heat exchanger. This aims to create a "rapid flow zone" with a high cooling medium velocity near the heat source to quickly remove heat, and a "slow flow zone" further away from the heat source to enhance heat dissipation. Furthermore, heat exchanger technology is continuously evolving, such as employing a composite reflux cavity structure with supporting pillars and filling it with a nano-liquid working medium to enhance capillary limit and thermal conductivity. Other solutions take a materials science approach, using aluminum-based graphite composite materials to prepare heat exchangers, utilizing the high thermal conductivity of graphite for heat homogenization. In air cooling, research has focused on improving the structure of finned heat sinks, such as by incorporating complex base plate channels, heat dissipation channels, and connecting channels, in an attempt to improve efficiency through convection cooling.

[0004] Nevertheless, the aforementioned existing technologies still have significant limitations. In particular, when using non-Newtonian fluids as cooling media, traditional channel designs reveal new incompatibilities. These non-Newtonian fluids possess the unique property that their apparent viscosity decreases with increasing shear rate (i.e., shear thinning). Theoretically, this viscosity reduction under shearing should enhance flow and heat transfer. However, traditional channel designs aim to maintain a stable flow field, and their channel structures (such as smooth walls and simple geometries) cannot provide sufficient and rationally distributed shear forces to effectively activate the shear thinning effect. As a result, in regions with low flow velocities or irregular channel structures, the fluid may maintain a high viscosity due to insufficient shearing, leading to increased flow resistance and potentially even deterioration in heat transfer. This means that existing conventional liquid-cooled plate channel designs not only struggle to actively utilize the shear thinning characteristics of non-Newtonian fluids to enhance heat transfer, but may also result in suboptimal heat dissipation efficiency at low pumping power due to the mismatch between fluid properties and channel structure, failing to achieve efficient heat dissipation for high heat flux densities with low energy consumption. Therefore, there is an urgent need for a new heat dissipation solution that can actively utilize the properties of non-Newtonian fluids to achieve a significant improvement in heat transfer intensity with low pump power. Summary of the Invention

[0005] The purpose of this invention is to provide a high-efficiency heat dissipation device based on non-Newtonian fluid and metal fins and its preparation method, which addresses the above-mentioned shortcomings and solves the problems of dependence on high pump speed in existing liquid cooling technology and poor application effect of non-Newtonian fluid in traditional flow channels.

[0006] This invention is achieved through the following scheme: A high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins includes a sealing cover, a base, and porous metal fins. The sealing cover has an internal cavity for the porous metal fins to fit into. The porous metal fins are mounted on the base. The sealing cover covers the base to form a sealed cavity structure. The sealing cover has a working fluid inlet and a working fluid outlet, which are connected to an external liquid cooling circulation system. The cooling working fluid is a non-Newtonian fluid.

[0007] Based on the above-mentioned efficient heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the size of the accommodating cavity is adapted to the size of the porous metal fins.

[0008] Based on the above-mentioned efficient heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the working fluid inlet and working fluid outlet can be symmetrically arranged along the center position of the sealing cover.

[0009] Based on the above-mentioned efficient heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the sealing cover and base are made of one or more of copper, aluminum, sintered fiber, and foam metal.

[0010] Based on the above-mentioned efficient heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the sealing cover and base are made of C1100 oxygen-free copper.

[0011] Based on the above-mentioned high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the thickness of the sealing cover and the base is between 0.1 and 5 mm.

[0012] Based on the above-mentioned high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the porous metal fins have a porosity of 80%-98%, and the porous metal fins are made of copper fiber felt with an average pore diameter of 0.8 mm.

[0013] Based on the above-mentioned efficient heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins, the cooling working fluid is specifically adopted as shear-thinned alumina nanofluid.

[0014] This solution also discloses a method for fabricating a high-efficiency heat dissipation device based on non-Newtonian fluids and metal fins, including the following steps: Step 1: Separately process the sealing cover, base, and porous metal fins according to the preset dimensions; Step 2: Place the processed porous metal fins into the cavity recess of the base, lay a layer of copper-based material foil on it, then cover it with a sealing cover and send it into a vacuum brazing furnace. Step 3: Brazing is performed in a vacuum brazing furnace. During the brazing process, the cold plate is permanently sealed. Then, standard threaded joints are welded to the inlet and outlet of the cooling medium, and the entire cold plate is subjected to helium mass spectrometry leak detection to ensure its sealing reliability.

[0015] In step one, the porous fins are made of sintered copper fiber felt with a porosity of 92% and an average pore diameter of 0.8 mm.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This scheme couples non-Newtonian fluids with porous fin structures, and uses the high shear field inside the porous medium to actively regulate the local viscosity of the working fluid, thereby achieving a synergistic enhancement effect of "low pump power and high heat transfer".

[0017] 2. The complex and rapidly changing micro-pore channels inside the porous fins in this design constitute countless natural high shear field generators. When the cooling working fluid flows through them, it will be subjected to strong shear and tensile forces.

[0018] 2. In this scheme, for shear-thinning non-Newtonian fluids, the apparent viscosity will drop sharply in these high-shear regions, the fluidity will increase instantaneously, and a local high-speed, low-viscosity "jet" will be formed.

[0019] 3. In this scheme, the low viscosity fluid significantly reduces flow resistance and enhances the convective heat transfer coefficient; the high-speed fluid jet ejected from the pores can strongly scour the surface of the porous skeleton and completely destroy the thermal boundary layer; the porous structure itself has a large surface area, providing a huge heat transfer area; the highly thermally conductive porous metal skeleton can quickly conduct heat from the heat source (bottom of the cold plate) to the entire fluid domain.

[0020] 4. The structure in this design allows the working fluid to automatically reduce its viscosity to enhance heat transfer when flowing through regions with high heat flux density, while in regions with high flow resistance, it recovers some viscosity due to reduced shear force, thus avoiding ineffective energy loss and achieving system-level energy efficiency optimization. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the entire invention; Figure 2 This is a schematic diagram of the overall exploded structure of the present invention; Figures 3-4 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 5 A schematic diagram of the fluid flow direction in a traditional non-porous, smooth, non-porous fin. Figure 6 This is a schematic diagram showing the fluid flow direction of a porous metal fin. Reference numerals: 1. Sealing cover; 2. Porous metal fins; 3. Base; 4. Cooling medium inlet; 5. Cooling medium outlet; 6. Cooling medium; 7. Cooling medium flow direction. Detailed Implementation

[0022] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0023] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0024] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a predetermined orientation, or be constructed and operated in a predetermined orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0026] Example 1 like Figures 1-6 As shown, the present invention provides a technical solution: A high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins 2 includes a sealing cover 1, a base 3, and porous metal fins 2. The sealing cover 1 has an internal cavity for the porous metal fins 2 to fit. The porous metal fins 2 are disposed on the base 3. The sealing cover 1 covers the base 3 to form a sealed cavity structure with the base 3. A working fluid inlet and a working fluid outlet are respectively provided on the sealing cover 1. The working fluid inlet and the working fluid outlet are connected to an external liquid cooling circulation system. The cooling working fluid 6 is a non-Newtonian fluid.

[0027] Based on the above structure, this solution allows for rapid heat transfer by directly contacting the porous metal fins 2 on the base 3. Simultaneously, by using a non-Newtonian fluid as the cooling medium 6, the shear-thinning properties of the non-Newtonian fluid are actively utilized to significantly improve heat transfer intensity with low pumping power consumption. The porous structure provides a large surface area and strong flow field disturbance, while the viscosity of the non-Newtonian fluid decreases under shearing action; the two work synergistically to enhance heat transfer. By actively reducing flow resistance through the "shear-thinning" effect, a larger flow rate and better heat transfer can be achieved with the same pumping power, or a significant reduction in pumping power consumption can be achieved with the same heat dissipation performance, resulting in quiet operation and energy saving. Furthermore, the heat dissipation effect can adaptively enhance with the heat load (the greater the heat flux, the greater the required heat dissipation, the greater the shear force obtained by the fluid flowing through the porous medium, the greater the viscosity reduction, and the stronger the heat transfer). This solution also integrates the heat exchange unit (porous fins) inside the cold plate, resulting in a compact overall structure with no moving parts, thus improving reliability.

[0028] As an example, the size of the accommodating cavity is adapted to the size of the porous metal fin 2.

[0029] Based on the above structure, gaps between the porous metal fins 2 and the sealing cover 1 can be avoided, reducing the effect of non-Newtonian fluids. This allows the cooling medium 6 to be sheared and thinned by the porous fins as soon as it enters the accommodating cavity.

[0030] As an example, the working fluid inlet and outlet can be symmetrically arranged along the center position of the sealing cover 1.

[0031] As an example, the sealing cover 1 and the base 3 can be made of one or more of copper, aluminum, sintered fiber, and foamed metal, preferably C1100 oxygen-free copper. Furthermore, the thickness of the sealing cover 1 and the base 3 can be between 0.1 and 5 mm, preferably 1 mm.

[0032] Based on the above structure, rapid heat transfer can be achieved by using metallic materials, and rapid heat dissipation can be achieved by using oxygen-free copper.

[0033] As an example, the porosity of the porous metal fin 2 is 80%-98%, preferably 92%, and the porous metal fin is made of copper fiber felt with an average pore size of 0.8 mm.

[0034] As an example, the cooling medium 6 specifically employs a shear-thinning alumina (Al2O3) nanofluid, which exhibits high apparent viscosity at low shear rates and a significant decrease in apparent viscosity at high shear rates. Porous metal fins 2 fill the cavity channels of the cold plate and are tightly thermally connected to the bottom plate of the cold plate. These porous fins have a three-dimensional interconnected network structure and are made of a high thermal conductivity metal, such as copper or aluminum alloy.

[0035] In this solution, the heat dissipation device is pressed onto the package of the heat-generating electronic device by fastening bolts, high thermal conductivity silicone grease is applied to the contact surface, and the cold plate is connected to the liquid cooling circulation system through a hose.

[0036] Example 2 This invention provides a technical solution: A method for fabricating a high-efficiency heat dissipation device based on non-Newtonian fluid and metal fins includes the following steps: Step 1: Separately process the sealing cover 1, the base 3, and the porous metal fins 2 according to the preset dimensions; Step 2: Place the processed porous metal fins 2 into the cavity recess of the base 3, lay a layer of copper-based material foil on it, then cover it with the sealing cover 1 and send it into the vacuum brazing furnace. Step 3: Brazing is performed in a vacuum brazing furnace. During the brazing process, the cold plate is permanently sealed. Then, the standard threaded joints are welded to the inlet and outlet of the cooling medium 6, and the entire cold plate is subjected to helium mass spectrometry leak detection to ensure its sealing reliability.

[0037] The working process of this device: (1) Initial state: The liquid cooling system is started, and the pump drives the nanofluid to flow into the cold plate inlet. At this time, the fluid viscosity is high.

[0038] (2) Shear thinning and microjets formation: such as Figure 6 As shown, when the cooling medium 6 flows through the porous metal fins 2, it is forced to travel through the tortuous and narrow pores and is subjected to extremely strong shearing action.

[0039] (3) Adaptive enhanced heat transfer: Under this high shear field triggering, the apparent viscosity of the non-Newtonian fluid decreases sharply, the fluidity is enhanced, and multiple high-speed, low-viscosity microjets are formed. These microjets can efficiently penetrate and destroy the thermal boundary layer, violently scour the surface of the porous metal fins 2, and quickly remove the heat generated by the electronic equipment. At the same time, the decrease in local viscosity also significantly reduces the flow resistance in the local area.

[0040] (4) Circulating heat dissipation: The heated non-Newtonian fluid flows out from the outlet and carries the heat to the external environment through the external liquid cooling cycle.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluids and porous metal fins (2), characterized in that, The system includes a sealing cover (1), a base (3), and porous metal fins (2). The sealing cover (1) has an internal cavity for the porous metal fins (2) to fit. The porous metal fins (2) are mounted on the base (3). The sealing cover (1) covers the base (3) to form a sealed cavity structure with the base (3). The sealing cover (1) has a working fluid inlet and a working fluid outlet. The working fluid inlet and the working fluid outlet are connected to an external liquid cooling circulation system. The cooling working fluid (6) is a non-Newtonian fluid.

2. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claim 1, characterized in that: The size of the accommodating cavity is adapted to the size of the porous metal fin (2).

3. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claim 2, characterized in that: The working fluid inlet and working fluid outlet can be symmetrically arranged along the center position of the sealing cover (1).

4. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claim 3, characterized in that: The sealing cover (1) and the base (3) are made of one or more of the following materials: copper, aluminum, sintered fiber, and foam metal.

5. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claims 1-4, characterized in that: The sealing cover (1) and the base (3) are made of C1100 oxygen-free copper.

6. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claims 1-4, characterized in that: The thickness of the sealing cover (1) and the base (3) is between 0.1 and 5 mm.

7. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claims 1-4, characterized in that: The porous metal fins (2) have a porosity of 80%-98%, and the porous metal fins are made of copper fiber felt with an average pore diameter of 0.8 mm.

8. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claims 1-4, characterized in that: The cooling medium (6) is specifically a shear-thinning alumina nanofluid.

9. A method for fabricating a high-efficiency heat dissipation device based on non-Newtonian fluids and metal fins, characterized in that: Includes the following steps: Step 1: Separately process the sealing cover (1), base (3) and porous metal fins (2) according to the preset dimensions. Step 2: Place the processed porous metal fins (2) into the cavity recess of the base (3), lay a layer of copper-based material foil on it, then cover it with a sealing cover (1) and send it into the vacuum brazing furnace. Step 3: Brazing is performed in a vacuum brazing furnace. During the brazing process, the cold plate is permanently sealed. Then, the standard threaded joints are welded to the inlet and outlet of the cooling medium (6) respectively, and the entire cold plate is subjected to helium mass spectrometry leak detection to ensure its sealing reliability.

10. The high-efficiency heat dissipation device for electronic devices based on non-Newtonian fluid and porous metal fins (2) according to claim 9, characterized in that: In step one, the porous fins are made of sintered copper fiber felt with a porosity of 92% and an average pore diameter of 0.8 mm.

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