Phase change heat dissipation device and manufacturing method thereof

Abstract

The present invention provides a phase-change heat dissipation device and a manufacturing method thereof, which relates to the technical field of heat dissipation devices and solves the problem of poor heat dissipation effect of the heat dissipation structure of the device in the prior art. The device includes a heat dissipation body and a phase-change material layer. The heat dissipation body is made of a heat-conducting material and is used to conduct the heat generated by the heat source; the phase-change material layer is arranged on the surface of the heat dissipation body and is used to absorb the heat conducted by the heat dissipation body by changing the physical form. The present invention combines the heat dissipation body and the phase-change material layer together, and the heat dissipation body is in contact with the heat source to dissipate the heat generated by the heat source, thereby increasing the heat exchange area dissipated by the device (heat source); on the other hand, by arranging the phase-change material layer on the surface of the heat dissipation body, the phase-change material layer can absorb the heat conducted by the heat dissipation body during the phase change process, thereby effectively reducing the operating temperature of the device. The phase-change heat dissipation device has a simple structure and is easier to achieve efficient heat dissipation.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation devices, and in particular to a phase change heat dissipation device and a manufacturing method thereof. Background Art

[0002] With the increase in device integration and the improvement in power density, device power consumption and heat generation increase dramatically. In such products, failures caused by overheating account for 65%-80% of the total failure rate. Heat dissipation management is a key factor that needs to be considered for stable device operation.

[0003] Taking the application of solar photovoltaic modules and thermoelectric devices as an example, the power generation of photovoltaic modules decreases by approximately 0.5% for every degree increase in temperature. Meanwhile, the heat dissipation capacity of thermoelectric devices also has a significant impact on the power generation and cooling performance of the devices. Therefore, achieving high heat flux density heat dissipation is of great significance in many heat dissipation fields.

[0004] Currently, the main means of solving device heat dissipation include:

[0005] 1) Forced liquid convection heat transfer, such as a water pump driving the liquid cooling medium to circulate and remove heat;

[0006] 2) Forced air cooling, such as a fan blowing on the fin surface to carry away the heat flow;

[0007] 3) Preparation of radiative heat dissipation coating to increase radiative heat exchange between itself and the surrounding environment.

[0008] However, the applicant has discovered that the above heat dissipation method has at least the following technical problems:

[0009] The above heat dissipation methods often have disadvantages such as complex structure, additional operating power consumption, and poor heat dissipation effect. Summary of the Invention

[0010] In view of this, in order to solve the technical problem of poor heat dissipation effect of the device heat dissipation structure in the prior art, an object of the present invention is to provide a phase change heat dissipation device and a manufacturing method thereof.

[0011] In order to achieve the above-mentioned object, the present invention provides a phase change heat dissipation device, comprising a heat dissipation body and a phase change material layer, wherein: the heat dissipation body is made of a heat conductive material and is used to conduct heat generated by a heat source;

[0012] The phase change material layer is arranged on the surface of the heat dissipation body and is used for absorbing the heat conducted by the heat dissipation body by changing the physical form.

[0013] As a further improvement of the present invention, the heat dissipation body is a heat dissipation fin structure, and the phase change material layer is a hydrogel layer.

[0014] As a further improvement of the present invention, the heat dissipation body includes a base and heat dissipation fins, a plurality of the heat dissipation fins are arranged on the base, and the phase change material layer is arranged on the surface of the base and / or the surface of the heat dissipation fins.

[0015] As a further improvement of the present invention, the heat dissipation ribs and the base are an integrated structure, a contact surface abutting the base exists on the heat source, and the surface shape of the base away from the heat dissipation ribs matches the shape of the contact surface.

[0016] As a further improvement of the present invention, the cross-section of the heat dissipation fins perpendicular to the axial direction thereof has a shape of a square, a triangle, a trapezoid or a circle, and the heat dissipation fins on the same base portion have the same or different shapes.

[0017] As a further improvement of the present invention, the base portion includes a base body and a base protective layer, and the base protective layer is arranged on the outer surface of the base body;

[0018] The heat dissipation fin comprises a fin body and a fin protection layer, wherein the fin protection layer is arranged on the outer surface of the fin body;

[0019] The phase change material layer is provided on the outer surface of the base protective layer and / or the outer surface of the fin protective layer.

[0020] As a further improvement of the present invention, the thickness of the phase change material layer provided on the heat dissipation body is 0.5 to 3 mm.

[0021] A method for manufacturing a phase-change heat dissipation device, wherein the heat dissipation body is a heat dissipation fin structure, and the phase-change material layer is a hydrogel layer, the manufacturing method comprising:

[0022] preparing a hydrogel mold and a heat dissipation fin structure;

[0023] placing the heat dissipation fin structure into a hydrogel mold;

[0024] preparing a hydrogel prepolymer solution;

[0025] pouring the prepared hydrogel prepolymer solution between the hydrogel mold and the heat dissipation fin structure inside the hydrogel mold, and allowing it to stand at room temperature to form a phase change material layer of the hydrogel prepolymer solution;

[0026] The heat dissipation fin structure and the phase change material layer thereon are demoulded from the hydrogel mold to obtain a phase change heat dissipation device.

[0027] As a further improvement of the present invention, the preparation of the hydrogel prepolymer solution comprises:

[0028] Acrylamide and N-isopropylacrylamide were mixed and dissolved in water at a mass ratio of 4:1 to obtain a two-component monomer solution, and N,N'-methylenebisacrylamide was added to obtain a mixed solution;

[0029] An aqueous solution of ammonium persulfate with a mass fraction of 10% is added to the mixed solution, and the mixture is mixed evenly in an ice bath, and then a tetramethylethylenediamine catalyst is added to obtain the hydrogel prepolymer solution.

[0030] As a further improvement of the present invention, the mass of the N,N'-methylenebisacrylamide is 0.5% of the total mass of acrylamide and N-isopropylacrylamide; and the volume ratio of the ammonium persulfate aqueous solution to the two-component monomer solution is 1:100.

[0031] The phase-change heat sink device provided by the present invention combines a heat sink body with a phase-change material layer. The heat sink body has excellent thermal conductivity. Through contact with a heat source, it dissipates heat generated by the heat source, increasing the heat exchange area dissipated by the device (heat source). Furthermore, by providing a phase-change material layer on the surface of the heat sink body, the phase-change material layer absorbs heat conducted by the heat sink body during phase change, effectively reducing the operating temperature of the device. This phase-change heat sink device has a simple structure and easily achieves efficient heat dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 1 is a schematic structural diagram of a phase change heat dissipation device provided by an embodiment of the present invention;

[0034] Figure 2 is a schematic structural diagram of a hydrogel mold provided by an embodiment of the present invention;

[0035] Figure 3 yes Figure 2 Cross-section view in the AA direction;

[0036] Figure 4 This is a comparison chart of the effects of the hydrogel, heat dissipation fin structure, and phase change heat dissipation device on the power generation performance of the thermoelectric device in Experiment 1 of the present invention;

[0037] Figure 5 is a graph showing the relationship between the cold end temperature and the generated voltage in Experiment 1 of the present invention;

[0038] Figure 6 This is a temperature control comparison diagram of the hydrogel, heat dissipation fin structure, phase change heat dissipation device and heat source heat output in Experiment 2 of the present invention;

[0039] Figure 7 It is a flow chart of a method for manufacturing a phase change heat dissipation device provided by an embodiment of the present invention.

[0040] Reference numerals: 1, heat dissipation body; 11, base portion; 12, heat dissipation ribs; 2, phase change material layer. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that, unless otherwise specified, "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

[0044] See also Figure 1 The present invention provides a phase-change heat sink device comprising a heat sink body 1 and a phase-change material layer 2. The heat sink body 1 is made of a thermally conductive material and is used to conduct heat generated by a heat source. The phase-change material layer 2 is disposed on the surface of the heat sink body 1 and absorbs the heat conducted by the heat sink body 1 by changing its physical form. This phase-change heat sink device has a simple structure, and the combination of the heat sink body 1 and the phase-change material layer 2 facilitates efficient heat dissipation.

[0045] As an optional implementation method of this embodiment, the heat dissipation body 1 is a heat dissipation fin structure, and the phase change material layer 2 is a hydrogel layer. The heat dissipation fin structure and the hydrogel layer are compounded together. The heat dissipation fin structure has excellent thermal conductivity. The heat dissipation fin structure is in contact with the heat source to dissipate the heat generated by the heat source, thereby increasing the heat exchange area dissipated by the device (heat source); on the other hand, by arranging a hydrogel layer on the surface of the heat dissipation fin structure, since water has a high latent heat, the evaporation of water in the hydrogel can take away a large amount of heat, thereby effectively reducing the operating temperature of the device. At the same time, the hydrogel itself has the function of adsorbing and storing water vapor. It can replenish water for the hydrogel by adsorbing wet steam in the environment or collecting rainwater, thereby ensuring the continuous and effective operation of the heat dissipation system and avoiding the increase in energy consumption caused by forced convection heat exchange and other methods. The phase change heat dissipation device has the advantages of simple structure, no additional energy consumption and low maintenance cost.

[0046] In this embodiment, the heat sink body 1 includes a base portion 11 and heat sink fins 12. The heat sink body 1 is made of metal or other materials with good thermal conductivity. A plurality of heat sink fins 12 are provided on the base portion 11. Preferably, the plurality of heat sink fins 12 are arranged parallel to each other. A phase change material layer 2 is provided on the surface of the base portion 11 and / or the surface of the heat sink fins 12. As needed, the phase change material layer 2 can be provided on the surface of the base portion 11 or on the surface of the heat sink fins 12. To achieve a better heat dissipation effect, preferably, the phase change material layer 2 is provided on the surfaces of both the heat sink fins 12 and the base portion 11.

[0047] The heat dissipation fins 12 are integrally formed with the base 11 and are easy to manufacture. The cross-section of the heat dissipation fins 12 perpendicular to their axis can be square, triangular, trapezoidal, or circular. The heat dissipation fins 12 on the same base 11 can be the same or different in shape, primarily to double the phase change heat dissipation area. The shapes can be adjusted as needed.

[0048] The heat source has a contact surface that abuts the base 11. The surface shape of the base 11 away from the heat dissipation fins 12 matches the shape of the contact surface. This allows the base 11 to better fit the heat source and effectively conduct heat from the heat source to the surface of the heat dissipation fins 12.

[0049] In addition, the base portion 11 in this embodiment includes a base body and a base protective layer disposed on the outer surface of the base body; the heat dissipation fins 12 include a fin body and a fin protective layer disposed on the outer surface of the fin body; and a phase change material layer 2 is disposed on the outer surface of the base protective layer and / or the outer surface of the fin protective layer. The addition of the base protective layer and the fin protective layer prevents moisture corrosion on the surface of the heat dissipation fin structure, thereby increasing the stability of heat dissipation performance.

[0050] The hydrogel layer is evenly adhered to the surface of the base 11 and the heat dissipation fins 12, thereby increasing the specific surface area of ​​the hydrogel and achieving large-area contact between the hydrogel layer and the heat source. The thickness of the phase change material layer 2 provided on the heat dissipation body 1 is 0.5 to 3 mm. The thickness of the hydrogel can be adjusted according to the needs of heat dissipation and hydration. The hydrogel layer can also completely fill the surface of the heat dissipation fin structure to achieve efficient heat exchange. The main function of the hydrogel layer is to store water and undergo phase change to remove the heat transferred from the heat source to the fins.

[0051] When the lower surface of base 11 (the surface away from heat sink fins 12) is heated, heat is transferred to the hydrogel layer through base 11 and heat sink fins 12. The water in the hydrogel evaporates, removing heat from the heat source and lowering the surface temperature of the heat source. This phase-change heat sink utilizes the heat sink fin structure to increase the surface area of ​​the hydrogel layer for phase-change heat transfer. By leveraging the hydrogel's ability to store water, it achieves efficient heat transfer via evaporative phase change on the heat source surface.

[0052] In addition, see Figure 7 The present invention also provides a method for manufacturing a phase change heat dissipation device, wherein the heat dissipation body 1 adopts a heat dissipation fin structure, and the phase change material layer 2 is a hydrogel layer. The manufacturing method comprises the following steps:

[0053] S1, preparing a hydrogel mold and a heat dissipation fin structure;

[0054] S2, placing the heat dissipation fin structure into the hydrogel mold;

[0055] S3, preparing a hydrogel prepolymer solution;

[0056] S4, pouring the prepared hydrogel prepolymer solution between the hydrogel mold and the heat dissipation fin structure inside the hydrogel mold, and letting it stand at room temperature to form the hydrogel prepolymer solution to form a phase change material layer 2;

[0057] S5. Demolding the heat dissipation fin structure and the phase change material layer 2 thereon from the hydrogel mold to obtain a phase change heat dissipation device.

[0058] When preparing the hydrogel mold, the hydrogel mold is processed according to the designed heat dissipation fin structure and the thickness of the hydrogel layer reserved in the heat dissipation fin structure. The hydrogel mold is made of polytetrafluoroethylene with strong hydrophobicity. The total height of the hydrogel mold is higher than the heat dissipation fin structure, which is convenient for hydrogel casting and curing. Figure 2 and Figure 3 shown.

[0059] Before the heat dissipating fin structure is installed into the hydrogel mold in step S2, the processed heat dissipating fin structure can be cleaned and then installed into the hydrogel mold after drying. During installation, the heat dissipating fins 12 of the heat dissipating fin structure face downward and the opening of the hydrogel mold faces upward.

[0060] In step S3, the preparation of the hydrogel prepolymer solution mainly includes the following steps:

[0061] S31, dissolving acrylamide and N-isopropylacrylamide in water at a mass ratio of 4:1 to obtain a two-component monomer solution, and then adding N,N'-methylenebisacrylamide to obtain a mixed solution;

[0062] S32. Add 10% by mass of an aqueous solution of ammonium persulfate to the mixed solution, mix evenly in an ice bath, and then add tetramethylethylenediamine as a catalyst to obtain a hydrogel prepolymer solution.

[0063] It should be noted that in the above step S31, the mass of N,N'-methylenebisacrylamide is 0.5% of the total mass of acrylamide and N-isopropylacrylamide; in step S32, the volume ratio of the ammonium persulfate aqueous solution to the two-component monomer solution is 1:100, and the concentration of the catalyst tetramethylethylenediamine in the hydrogel prepolymer solution is 0.5 μL / mL.

[0064] In step S4, the prepared hydrogel prepolymer solution is poured between the hydrogel mold and the heat dissipation fin structure inside the hydrogel mold, and left to stand at room temperature for 3 hours until the hydrogel prepolymer solution is gelled.

[0065] Because the bonding strength between the hydrogel layer and the heat sink fin structure is much stronger than that between the hydrogel layer and the (PTFE) hydrogel mold, the heat sink fin structure and hydrogel layer can be easily peeled off from the hydrogel mold surface after gel formation, ultimately forming a highly absorbent hydrogel layer of the desired thickness on the heat sink fin structure. Finally, the excess hydrogel layer at the edge of the heat sink fin structure is removed with a blade, completing the fabrication of the phase change heat sink device.

[0066] The phase change heat dissipation device manufactured by the above method can be used in thermal power generation of thermoelectric devices, and can also be used for constant heat flow heat dissipation.

[0067] Experiment 1:

[0068] The phase change heat sink is used in thermoelectric devices for thermal power generation. The lower surface of the base portion 11 is mounted on the cold end of the thermoelectric device through thermal grease. The temperature of the hot end of the thermoelectric device is adjusted, and the cold end temperature of the thermoelectric device and the maximum power generation of the thermoelectric device are tested at different hot end temperatures. The experimental data are analyzed using pure hydrogel heat dissipation as comparative example 1 and pure fin (heat dissipation fin structure) heat dissipation as comparative example 2 to evaluate the heat dissipation effect of the composite heat dissipation device of the hydrogel layer and the heat dissipation fin structure. The results are shown in the figure. Figure 4 shown.

[0069] from Figure 4 It can be seen that at the same hot-end temperature, the composite phase-change heat dissipation device of the heat dissipation fin structure and the hydrogel layer, compared with comparative example 1 (heat dissipation through hydrogel), has an increased surface area of ​​the composite heat dissipation device of the hydrogel layer and the heat dissipation fin structure, and the total heat dissipation increases, so that the cold-end temperature of the thermoelectric device is lower under the same working conditions, and the power generation increases by more than 60%. Compared with comparative example 2 (heat dissipation through the heat dissipation fin structure), phase-change heat transfer can effectively improve the heat transfer coefficient of the thermoelectric device, significantly reduce the cold-end temperature of the thermoelectric device, and significantly improve the temperature difference between the hot and cold ends of the thermoelectric device, ultimately increasing the power generation of the thermoelectric device by 4-8 times under the same working conditions. Here, the hot-end temperature of the thermoelectric device is controlled by a hot and cold stage, and the cold-end temperature is difficult to test because the thermoelectric device is connected to the phase-change heat dissipation device. Therefore, by calibrating the relationship between the power generation voltage and the cold-end temperature of the thermoelectric device, the corresponding curves between the two are obtained, and then the corresponding cold-end temperature value is obtained by interpolation on the curve graph according to the power generation voltage obtained during the test, as shown in FIG. Figure 5 shown.

[0070] Experiment 2:

[0071] The phase change heat dissipation structure in this embodiment is used for constant heat flow heat dissipation. A polyimide film heater is used as a simulated heat source. The lower surface of the base portion 11 in the heat dissipation fin structure is bonded to the polyimide film heater by a thermally conductive adhesive. A layer of thermal insulation pad is installed on the surface of the heater away from the thermally conductive adhesive to ensure that all heat is dissipated through the heat dissipation fin structure. The heating power of the heater is adjusted, and the temperature of the heat source under different heat flow rates is tested respectively. The experimental data are analyzed with simple hydrogel heat dissipation as comparative example 1 and simple fin heat dissipation as comparative example 2 to evaluate the heat dissipation effect of the composite heat dissipation device of the hydrogel layer and the heat dissipation fin structure. Figure 6 shown.

[0072] from Figure 6It can be seen that under the same heat flow, the phase change heat dissipation device composed of the heat dissipation fin structure and the hydrogel layer in this embodiment achieves a good temperature control effect on the heat source compared with Comparative Examples 1 and 2. It can control the temperature of the heat source with a heat dissipation of less than 10W to within 60°C, which can effectively improve the heat dissipation of the heat source and significantly reduce the temperature of the heat source, which is of great significance in the field of device heat dissipation.

[0073] In summary, the phase change heat dissipation device provided in this embodiment combines the phase change material layer 2 (hydrogel layer) through the heat dissipation fin structure, utilizes the phase change of water evaporation in the hydrogel to improve the heat transfer coefficient, and utilizes the heat dissipation fin structure to achieve the doubling of the phase change area, thereby greatly improving the heat dissipation capacity of the heat dissipation device.

[0074] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A phase change heat dissipation device, characterized in that: It includes a heat dissipation body and a phase change material layer, wherein: the heat dissipation body is made of a heat-conducting material and is used to conduct heat generated by a heat source; The phase change material layer is provided on the surface of the heat dissipation body and is used to absorb the heat conducted by the heat dissipation body by changing its physical form; The heat dissipation body is a heat dissipation fin structure, and the phase change material layer is a hydrogel layer; The heat dissipation body includes a base and heat dissipation ribs, a plurality of the heat dissipation ribs are provided on the base, and the phase change material layer is provided on the surface of the base and / or the surface of the heat dissipation ribs; The base portion includes a base body and a base protective layer, and the base protective layer is arranged on the outer surface of the base body; The heat dissipation fin comprises a fin body and a fin protection layer, wherein the fin protection layer is arranged on the outer surface of the fin body; The phase change material layer is provided on the outer surface of the base protective layer and / or the outer surface of the fin protective layer.

2. The phase change heat dissipation device according to claim 1, characterized in that: The heat dissipation ribs and the base are an integrated structure. A contact surface abutting against the base exists on the heat source. The shape of the surface of the base away from the heat dissipation ribs matches the shape of the contact surface.

3. The phase change heat dissipation device according to claim 1, characterized in that: The cross-section of the heat dissipation fin perpendicular to the axial direction thereof has a shape of a square, a triangle, a trapezoid or a circle, and the heat dissipation fins on the same base portion have the same or different shapes.

4. The phase change heat dissipation device according to claim 1, characterized in that: The thickness of the phase change material layer provided on the heat dissipation body is 0.5-3 mm.

5. A method for manufacturing a phase change heat dissipation device according to any one of claims 1 to 4, characterized in that: The heat dissipation body is a heat dissipation fin structure, the phase change material layer is a hydrogel layer, and the manufacturing method includes: preparing a hydrogel mold and a heat dissipation fin structure; placing the heat dissipation fin structure into a hydrogel mold; preparing a hydrogel prepolymer solution; pouring the prepared hydrogel prepolymer solution between the hydrogel mold and the heat dissipation fin structure inside the hydrogel mold, and allowing it to stand at room temperature to form a phase change material layer of the hydrogel prepolymer solution; The heat dissipation fin structure and the phase change material layer thereon are demoulded from the hydrogel mold to obtain a phase change heat dissipation device.

6. The method for manufacturing a phase change heat dissipation device according to claim 5, wherein: The preparation of the hydrogel prepolymer solution comprises: Acrylamide and N-isopropylacrylamide were mixed and dissolved in water at a mass ratio of 4:1 to obtain a two-component monomer solution, and N,N'-methylenebisacrylamide was added to obtain a mixed solution; An aqueous solution of ammonium persulfate with a mass fraction of 10% was added to the mixed solution, and the mixture was mixed evenly in an ice bath, and then a tetramethylethylenediamine catalyst was added to obtain the hydrogel prepolymer solution.

7. The method for manufacturing a phase change heat dissipation device according to claim 6, wherein: The mass of the N,N'-methylenebisacrylamide is 0.5% of the total mass of acrylamide and N-isopropylacrylamide; the volume ratio of the ammonium persulfate aqueous solution to the two-component monomer solution is 1:100.

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