Heat pipe with efficient heat dissipation performance and preparation method thereof

Abstract

The invention discloses a heat pipe with efficient heat dissipation performance and a preparation method thereof. The heat pipe comprises a metal shell, a liquid absorption core arranged on the inner wall of the metal shell and a liquid working medium filled in the metal shell, the liquid absorption core is metal aerogel with a nanowire structure, the length direction of the nanowire structure is consistent with the length direction of the heat pipe, the heat pipe further comprises a metal connecting layer, and the metal connecting layer is arranged between the metal shell and the liquid working medium. The metal connecting layer is arranged between the inner wall of the metal shell and the wick and used for connecting the metal shell and the wick. The heat pipe has the advantages of rapid liquid absorption and efficient heat transfer, and can be used in the field of efficient heat dissipation.

Description

Technical Field

[0001] The present invention relates to the field of heat conduction technology, and in particular to a heat pipe with high-efficiency heat dissipation performance and a preparation method thereof. Background Art

[0002] As the performance of electronic equipment continues to improve, heat dissipation has become one of the key factors restricting its development. Traditional heat dissipation technology has been unable to meet the growing demand for heat dissipation, especially in high power density application scenarios. As an efficient heat conduction device, heat pipes are widely used in electronic equipment heat dissipation, LED lighting, aerospace and other fields due to their excellent thermal conductivity. The wick is an important component of the heat pipe, mainly used to absorb liquid working fluid and transport it to the evaporation section. However, the wick materials of traditional heat pipes, such as powders, fibers, etc., often have problems such as low thermal conductivity efficiency and limited liquid absorption capacity, which makes the heat pipe unable to adapt well to the needs of different application scenarios.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a heat pipe with high-efficiency heat dissipation performance and a preparation method thereof.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, a heat pipe with high-efficiency heat dissipation performance is provided, comprising a metal shell, a liquid wick arranged on the inner wall of the metal shell, and a liquid working medium filled in the metal shell, wherein the liquid wick is a metal aerogel with a nanowire structure, and the length direction of the nanowire structure is consistent with the length direction of the heat pipe. The heat pipe also includes a metal connecting layer, which is arranged between the inner wall of the metal shell and the liquid wick to connect the metal shell and the liquid wick.

[0007] In a second aspect, a method for preparing the heat pipe according to the first aspect is provided, which comprises the following steps:

[0008] S1, preparing a metal aerogel with a nanowire structure having a predetermined orientation as a liquid wick;

[0009] S2, forming a metal connection layer on the inner wall of the metal shell of a predetermined shape;

[0010] S3, inserting the metal aerogel into the metal shell in such a way that the length direction of the nanowire structure of the metal aerogel is consistent with the length direction of the heat pipe, and then heating the heat pipe to a temperature above the melting point of the metal connecting layer so that the metal aerogel is fixed to the inner wall of the metal shell;

[0011] S4, sealing one end of the heat pipe, filling it with liquid working medium and evacuating it;

[0012] S5. Seal the other end of the heat pipe.

[0013] The present invention has the following beneficial effects: the heat pipe of the present invention adopts a nanostructured metal aerogel with specific orientation and super-hydrophilic properties as a liquid absorption core. This orientation not only improves the heat conduction and liquid absorption efficiency at the microscopic level, but can also be observed by visual inspection at the macroscopic level, thereby facilitating directional adjustment and optimization in practical applications to enhance the heat transfer efficiency of the heat pipe. The heat pipe has the advantages of rapid liquid absorption and efficient heat transfer (high heat dissipation performance), and can be used in the field of efficient heat dissipation.

[0014] In some technical solutions, low-temperature welding technology of low-melting-point metal coating is used to achieve a stable connection between the liquid wick and the inner wall of the metal shell, which reduces energy consumption and improves production efficiency. In addition, the metal aerogel liquid wick has excellent resilience and adjustability in shape and size, allowing the heat pipe to better meet the needs of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a macroscopic image of the metal aerogel with a nanowire structure prepared in Example 2 of the present invention;

[0016] Figure 2A and Figure 2B They are respectively SEM images of the metal aerogel with a nanowire structure according to Example 2 of the present invention at different magnifications;

[0017] Figure 3 The water absorption capacity test result of the metal aerogel in Example 2 of the present invention;

[0018] Figure 4 This is the test result of the ethanol adsorption capacity of the metal aerogel in Example 2 of the present invention;

[0019] Figure 5 is a schematic diagram of a cylindrical heat pipe in Example 1 of the present invention;

[0020] Figure 6 is a schematic diagram of a rectangular heat pipe in Example 2 of the present invention;

[0021] Figure 7 This is the compression resistance test result of the metal aerogel in Example 2 of the present invention. DETAILED DESCRIPTION

[0022] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its application. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In this article, the unit M represents mol / L, and the unit mM represents mmol / L.

[0023] A specific embodiment of the present invention provides a heat pipe with high-efficiency heat dissipation performance, comprising a metal shell, a liquid wick arranged on the inner wall of the metal shell, and a liquid working medium filled in the metal shell, wherein the liquid working medium is used for heat transfer of the heat pipe, the liquid wick is a metal aerogel with a nanowire structure, and the length direction of the nanowire structure is consistent with the length direction of the heat pipe. The heat pipe also includes a metal connecting layer, which is arranged between the inner wall of the metal shell and the liquid wick to connect the metal shell and the liquid wick.

[0024] The metal aerogel with a nanowire structure has a specific orientation (the length direction of each nanowire is basically the same), so it has super hydrophilicity. The length direction of its nanowires is consistent with the length direction of the heat pipe (that is, the two are parallel), which can significantly improve the liquid absorption and capillary suction capacity of the heat pipe, thereby improving the heat transfer efficiency of the heat pipe and achieving efficient mass transfer.

[0025] In some embodiments, the nanowire structure has a diameter of 1-5000 nm, preferably, a diameter of 200-2000 nm.

[0026] In some embodiments, the aspect ratio of the nanowire structure is 10 7 :1-10 1 :1, preferably, the aspect ratio is 10 6 :1-10 4 :1.

[0027] In some embodiments, the metal connection layer is a low melting point metal plating layer, and the melting point is 25°C-400°C.

[0028] In some embodiments, the metal aerogel is made of non-precious metals such as nickel, cobalt, iron, copper, or their alloys, or precious metals such as Au, Ag, Pt, Pd, or their alloys. More preferably, the metal aerogel with a nanowire structure is made of a ferromagnetic metal or metal alloy; more preferably, the metal aerogel with a nanowire structure is made of nickel, cobalt, iron, steel, or their alloys.

[0029] In some embodiments, the low melting point metal is at least one of indium, tin, bismuth, gallium, and zinc; and the thickness of the low melting point metal coating is 50 nm-1 mm.

[0030] In some embodiments, the metal aerogel is firmly connected to the low melting point metal coating on the inner wall of the metal shell by welding, and preferably the welding temperature is 1-400° C. above the melting point of the metal connection layer and less than 500° C.

[0031] In some embodiments, the porosity of the metal aerogel with a nanowire structure is 30%-99%, and the porosity of the metal aerogel liquid-absorbing core enhances its liquid absorption and heat transfer performance. The metal aerogel with a nanowire structure has elastic properties and can rebound after compression, which can ensure that the heat pipe does not experience structural collapse and irreversible deformation during use.

[0032] In some embodiments, the metal shell is made of a metal with good conductivity such as silver, copper, aluminum, stainless steel, or an alloy thereof, and is formed into the desired tubular shape by common metal forming methods, such as stretching, stamping, welding, casting, powder metallurgy, CNC machining, 3D printing, and other forming methods.

[0033] In some embodiments, the liquid working fluid is a conventional heat pipe working fluid such as water, ethanol, methanol, acetone, etc. Preferably, the liquid working fluid is water and ethanol.

[0034] In some embodiments, when the liquid working medium contains water and the standard electrode potential of the metal on the inner surface of the heat pipe is lower than 0V, the inner surface of the heat pipe in contact with water also has a layer of metal with a standard electrode potential greater than 0V, for example, the inner surface of the heat pipe in contact with water (the surface containing the metal aerogel and other exposed surfaces inside the heat pipe, etc.) is plated with the metal with a standard electrode potential greater than 0 (such as copper, silver, bismuth, gold, etc.) by electroplating, chemical plating, etc., to ensure the long-term and efficient heat dissipation stability of the heat pipe. The specific embodiment of the present invention also provides a method for preparing the heat pipe, which comprises the following steps:

[0035] S1, preparing a metal aerogel with a nanowire structure having a predetermined orientation as a liquid wick;

[0036] S2, forming a metal connection layer on the inner wall of the metal shell of a predetermined shape;

[0037] S3, inserting the metal aerogel into the metal shell in such a way that the length direction of the nanowire structure of the metal aerogel is consistent with the length direction of the heat pipe, and then heating the heat pipe to a temperature above the melting point of the metal connection layer so that the metal aerogel is fixed to the inner wall of the metal shell; specifically, observing a side of the metal aerogel with a clear macroscopic orientation and adjusting the orientation of the metal aerogel so that its macroscopic orientation is parallel to the direction of the heat pipe, so that the nanowire structure of the aerogel is parallel to the length direction of the heat pipe, inserting a number of metal aerogels into the heat pipe in the above direction so that the nanowire structure of the aerogel is parallel to the heat pipe, and then heating the heat pipe to a temperature above the melting point of the metal connection layer by 1-400°C and less than 500°C, so that the metal aerogel is welded and fixed to the inner surface of the heat pipe;

[0038] S4, sealing one end of the heat pipe (for example, by welding and sealing with low-temperature solder), filling with liquid working fluid and evacuating;

[0039] S5. Seal the other end of the heat pipe (for example, by welding and sealing with low-temperature solder).

[0040] In some embodiments, in step S1, the metal aerogel is prepared by a sol-gel method combined with a magnetic field induction step. The sol-gel method can accurately control the formation of nanowires, and the magnetic field induction step can guide the nanowires to be arranged in a specific direction, thereby obtaining a metal aerogel with typical orientation characteristics. This orientation of the metal aerogel can be visually observed at the macroscopic level, so that the position of the aerogel can be selectively adjusted to achieve the arrangement of the nanowires along the length direction of the heat pipe.

[0041] In some embodiments, the metal aerogel is nickel aerogel, and its preparation comprises the following steps:

[0042] (1) preparing a solution A of 0.01-10M nickel salt, 0.01-10M complexing agent, and 0.01-10mM H2PtCl6; wherein, preferably, the nickel salt is at least one of NiCl2, nickel sulfate, nickel acetate, and nickel nitrate, the complexing agent is citrate or an organic acid, preferably the citrate is Na3C6H5O7, and the organic acid is at least one of ethylenediaminetetraacetic acid and tartaric acid;

[0043] (2) preparing a reducing agent and deionized water into a solution B, wherein the concentration of the reducing agent in the solution B is 0.1-30 vol.%, wherein preferably, the reducing agent is at least one of hydrazine hydrate, oxalic acid, sodium borohydride, and sodium hypophosphite;

[0044] (3) respectively adjusting the pH of solution A and solution B to 7-14, for example, using an alkaline solution such as KOH, NaOH, Ba(OH)2 to adjust the pH of solution A and solution B to 7-14;

[0045] (4) preheating solution A and solution B to a reaction temperature respectively; preferably, the reaction temperature is 30-100° C.;

[0046] (5) Mixing solution A and solution B in a mold of a predetermined shape (the inner wall dimensions (length, width, height, diameter, etc.) of the mold are slightly larger than the inner diameter of the heat pipe) according to the molar ratio of the nickel salt in solution A to the reducing agent in solution B of 2:1-1:20, and placing the mold in a water bath to maintain the temperature at the reaction temperature;

[0047] (6) placing the entire reaction device of step (5) into a Helmholtz coil, ensuring that the mold containing solution A and solution B is at the center of the Helmholtz coil, applying power and adjusting the current to adjust the magnetic induction intensity to a predetermined value, and reacting to obtain a nickel aerogel having a predetermined orientation; preferably, the magnetic induction intensity is 50-2000 Gs, and the reaction time is 1-120 min; more preferably, the magnetic induction intensity is 50-500 Gs, and the reaction time is more preferably 50-120 min;

[0048] (7) The obtained nickel aerogel is repeatedly washed with deionized water until the pH of the cleaning solution is neutral, and then the washed nickel aerogel is air-dried (for example, dried for 48 hours) to obtain a nickel aerogel of a predetermined shape and size.

[0049] In addition to the above-mentioned sol-gel method, the nanowire structure can also be prepared by dealloying, template method, 3D printing method, etc. The size and shape of the shell can be adjusted according to the actual application requirements, and the shape of the metal aerogel can also be adjusted according to the specific design and application requirements of the heat pipe. The shape and size of the metal aerogel can be controlled during preparation, and a shape that is completely consistent with the inner surface of the heat pipe can be obtained. For example, when the heat pipe is rectangular, the size of the rectangular wick can be: thickness 0.2-100mm, width 0.2-100mm, length 0.2-1000mm; when the heat pipe is cylindrical, the size of the cylindrical wick can be: diameter 0.2-100mm, length 0.2-1000mm.

[0050] In some embodiments, step S2 comprises the following steps:

[0051] S21. Cleaning the inner wall surface of the metal housing; for example, by ultrasonic cleaning or chemical cleaning agent;

[0052] S22. Use a plating solution containing the metal elements in the metal connecting layer (the plating solution contains metal salts, chelating agents, reducing agents, stabilizers, etc.) to plate a coating of a predetermined thickness on the inner surface of the metal shell. Preferably, the plating method is at least one of chemical plating, electroplating, and coating. More preferably, the plating method is chemical plating.

[0053] S23, washing and drying the product obtained in step S22.

[0054] In some embodiments, when the liquid working fluid contains water and the standard electrode potential of the metal on the inner surface of the heat pipe is lower than 0V, it also includes forming a layer of metal with a standard electrode potential greater than 0V on the inner surface of the heat pipe in contact with water, for example, the inner surface of the heat pipe in contact with water (the surface containing the metal aerogel and other exposed surfaces inside the heat pipe, etc.) is plated with the metal with a standard electrode potential greater than 0 (for example, copper, silver, bismuth, gold, etc.) by electroplating, chemical plating, etc., to ensure long-term and efficient heat dissipation stability of the heat pipe.

[0055] The microstructure of the metal aerogel in the specific embodiment of the present invention is a nanowire structure, and the orientation of the nanowire structure is achieved through a specific growth technology (for example: magnetic field induction). This orientation not only improves the heat conduction and liquid absorption efficiency at the microscopic level, but can also be observed by visual observation at the macroscopic level, so as to facilitate directional adjustment and optimization in practical applications. Through the implementation of the present invention, not only the heat dissipation efficiency of the heat pipe can be improved, but also the size and shape of the liquid absorption core and the overall structure of the heat pipe can be adjusted according to specific application requirements, thereby achieving a more flexible and efficient heat dissipation solution. The implementation of these technologies is expected to provide strong support for efficient heat dissipation in the fields of electronic equipment, LED lighting, aerospace, etc.

[0056] The following further describes specific embodiments of the present invention. The raw materials used in the following embodiments, unless otherwise specified, can be obtained from conventional commercial sources, and the processes used, unless otherwise specified, are conventional processes in the art.

[0057] Example 1

[0058] Super-hydrophilic nickel metal aerogel as a cylindrical heat pipe with a liquid wick, e.g. Figure 5 The preparation of the heat pipe includes the following steps:

[0059] (1) A copper sheet with a thickness of 0.15 mm is used to obtain a round copper tube 1 through conventional molding.

[0060] (2) Clean the inner surface of the copper tube 1 using ultrasonic waves or a chemical cleaner.

[0061] (3) chemically plating an indium layer 2 on the inner surface of the circular copper tube 1, specifically comprising the following steps:

[0062] a. Add 2.27 g of indium sulfate powder to deionized water, add 20 ml of dilute sulfuric acid (10 wt.%) to assist in dissolution, stir and shake until the solution is clear and transparent to obtain solution A;

[0063] b. Weigh 3.36 g of disodium ethylenediaminetetraacetate, 0.6 g of hydroquinone, and 3 g of triethanolamine, respectively, and dissolve them in deionized water. After the solute is completely dissolved, stir to obtain solution B;

[0064] c. Prepare several milliliters of NaOH solution with a concentration of 2g / ml for use as a pH regulator;

[0065] d. Mix solution A and solution B and stir, adjust the pH of the plating solution to between 9.0 and 10.0 using a sodium hydroxide solution at room temperature, continue stirring the solution during the pH adjustment process, and obtain a mixed solution C after stirring evenly;

[0066] e. Weigh 2 g of sodium borohydride and dissolve it in 20 mL of deionized water to obtain solution D for later use;

[0067] f. Cover the outer surface of the copper tube 1 with a protective film to prevent contact with the plating solution, pour the mixed solution C into the container containing the copper tube 1, place it in a magnetic stirrer heated to 80°C for continuous electromagnetic stirring, use a burette to titrate the solution D into the solution at a titration rate of 1 mL / min, and react for 10 minutes after the titration to obtain an indium plating layer 2 on the inner surface of the copper tube 1;

[0068] g. Take out the copper tube, remove the protective film on the outer surface of the heat pipe and clean it with water and ethanol, dry it and set it aside.

[0069] (4) Preparing a metal nickel aerogel 3 having a nanowire structure as a liquid wick. Specifically, the steps include:

[0070] a. Prepare solution A containing 0.35M NiCl2, 0.12M Na3C6H5O7, and 0.3mM H2PtCl6;

[0071] b. Add a certain amount of hydrazine hydrate to deionized water to prepare solution B, wherein the concentration of hydrazine hydrate is 8.5 vol.%;

[0072] c. Then, the pH values ​​of solution A and solution B were adjusted to 13 using 6M KOH solution;

[0073] d. Add 25 mL of solution A and solution B to two beakers respectively, and place them in a water bath at 80°C for 5 minutes to preheat them. Make sure the preheating temperature is the same as the temperature during the reaction.

[0074] e. At the beginning of the reaction, mix solution A and solution B into a 80 mL custom round glass mold (the inner wall size of the mold is slightly larger than the inner diameter of the copper tube), stir quickly and thoroughly, and then put it into an 80°C water bath;

[0075] f. Place the entire reaction device into the center of the Helmholtz coil, power on and adjust the current so that the magnetic induction intensity is 300 Gs, and the reaction time is 48 min. After the reaction is completed, the metal nickel aerogel 3 is obtained;

[0076] g. The obtained nickel aerogel 3 is repeatedly washed with deionized water until the pH of the cleaning solution is neutral, and then the washed hydrogel is air-dried for 48 hours to obtain a cylindrical nickel aerogel 3 of a certain size.

[0077] (5) Observe the side of the metal aerogel with clear macroscopic orientation and adjust the position of the metal aerogel so that its macroscopic orientation is parallel to the direction of the heat pipe, that is, the nanowire structure of the aerogel is parallel to the length direction of the heat pipe, and insert a number of the above-mentioned metal nickel aerogels 3 into the indium-plated copper tube and heat it to above the melting point of metal indium (170-180° C.), so that the metal aerogel is welded and fixed to the inner surface of the heat pipe;

[0078] (6) using a common chemical copper plating method to plate a copper metal layer on the inner surface of the heat pipe;

[0079] (7) One end of the heat pipe is sealed by welding with low-temperature solder, filled with water as liquid working fluid and evacuated;

[0080] (8) The other end of the heat pipe is welded with low-temperature solder to form a closed heat pipe.

[0081] Example 2

[0082] Rectangular heat pipe with super-hydrophilic nickel metal aerogel as liquid wick, e.g. Figure 6 As shown, the preparation of the heat pipe includes the following steps:

[0083] (1) A copper sheet with a thickness of 0.3 mm is used to obtain a rectangular copper tube 1 through conventional molding.

[0084] (2) Clean the inner surface of the rectangular copper tube 1 using ultrasonic or chemical cleaning agents.

[0085] (3) A tin layer 2 is chemically deposited on the inner surface of the circular copper tube 1. The chemical tinning liquid used in this example is the HSN-800 series produced by Shenzhen Hongxi Technology Development Co., Ltd. According to the tinning process provided by the company, the tinning process of this example includes the following steps:

[0086] a. Degrease and clean the surface of the copper tube 1 to ensure that there is no oil stain, rust or other impurities;

[0087] b. Micro-etching: Use 10% hydrochloric acid solution and immerse the copper tube 1 in it for 2 to 3 minutes. During this process, the outer surface of the copper tube 1 needs to be covered with a protective film to prevent contact with the corrosive solution and the plating solution in the subsequent process;

[0088] c. Pre-dip, prepare the pre-dip solution according to the following concentrations (volume%, % v / v): 94% tin opener HSN-800M, 4.5% tin concentrate TIN-300, 1.5% tin additive HSN-800Add, stir well, and place the heat pipe in the pre-dip solution for pretreatment for 30 seconds;

[0089] d. Tinning: prepare a tinning solution according to the following concentrations (volume%, %v / v): 47% tinning agent HSN-800M, 2.25% tin concentrate TIN-300, 0.75% tinning additive HSN-800Add, stir well, and place the heat pipe in the tinning solution for 180 seconds to obtain a tinned layer on the inner surface of the copper tube 1;

[0090] e. Take out the copper tube 1, remove the protective film on the outer surface of the heat pipe and clean it with water and ethanol, dry it and set it aside.

[0091] (4) Preparing a metal nickel aerogel 3 having a nanowire structure as a liquid wick. Specifically, the steps include:

[0092] a. Prepare solution A containing 0.35M NiCl2, 0.12M Na3C6H5O7, and 0.30mM H2PtCl6;

[0093] b. Add a certain amount of hydrazine hydrate to deionized water to prepare solution B, wherein the concentration of hydrazine hydrate is 8.5 vol.%;

[0094] c. Use 6M KOH solution to adjust the pH value of solution A and solution B to 13;

[0095] d. Add 30 mL of solution A and solution B to two beakers respectively, and place them in a water bath at 80°C for 5 minutes to preheat them. Make sure the preheating temperature is the same as the temperature during the reaction.

[0096] e. At the beginning of the reaction, mix solutions A and B into a 100 mL custom square glass mold (the inner wall size of the mold is slightly larger than the inner diameter of the copper tube), stir quickly and thoroughly, and then put it into an 80°C water bath;

[0097] f. Place the entire reaction device into the center of the Helmholtz coil, power on and adjust the current so that the magnetic induction intensity is 300 Gs, and the reaction time is 60 min. After the reaction is completed, the metal nickel aerogel 3 is obtained;

[0098] g. The obtained nickel aerogel 3 is repeatedly washed with deionized water until the pH of the washing solution is neutral, and then the washed hydrogel is air-dried for 48 hours to obtain a square nickel aerogel 3 of a certain size.

[0099] (5) inserting a number of the above-mentioned metal nickel aerogels 3 into the copper tube 1 and heating the copper tube 1 to a temperature above the melting point of metal tin, so that the metal aerogels are welded and fixed to the inner surface of the heat pipe;

[0100] (6) using a common chemical copper plating method to plate a copper metal layer on the inner surface of the heat pipe;

[0101] (7) One end of the heat pipe is sealed by welding with low-temperature solder, filled with ethanol as a liquid working fluid and evacuated;

[0102] (8) The other end of the heat pipe is welded with low-temperature solder to form a closed heat pipe.

[0103] like Figure 1 The macroscopic image of the metal aerogel with nanowire structure prepared in this embodiment is shown as follows. Figure 2A and 2B Shown are SEM images of the metal aerogel with a nanowire structure prepared in this example at different magnifications. Figure 3 The results of the water absorption test of the metal aerogel of this embodiment (including dropping pure water on the metal aerogel before oxidation and after oxidation in air at 150°C for 1 hour), show that the water absorption and hydrophilicity of the liquid absorbent core do not change before and after oxidation (super-fast water absorption within 0.05s), that is, the experiment proves that even if the metal aerogel is oxidized, it still has strong water absorption and hydrophilicity. Figure 4 The results of the metal aerogel adsorption capacity test of this embodiment (including dripping anhydrous ethanol on the metal aerogel before oxidation and after oxidation in air at 150°C for 1 hour), the results show that before and after oxidation, the liquid absorbent core exhibits super alcohol affinity and strong ethanol adsorption characteristics (ultra-fast ethanol adsorption within 0.05s), that is, the experiment proves that even if the metal aerogel is oxidized, it still has strong alcohol affinity and strong ethanol adsorption characteristics. Figure 7 The figure shows the compression resistance test result of the metal aerogel of this embodiment, which proves that it has good elastic properties.

[0104] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A heat pipe with high heat dissipation performance, comprising a metal shell, a liquid wick arranged on the inner wall of the metal shell and a liquid working medium filled in the metal shell, characterized in that: The liquid wick is a metal aerogel with a nanowire structure, the length direction of the nanowire structure is consistent with the length direction of the heat pipe, and the heat pipe also includes a metal connecting layer, which is arranged between the inner wall of the metal shell and the liquid wick to connect the metal shell and the liquid wick.

2. The heat pipe according to claim 1, characterized in that: The diameter of the nanowire structure is 1-5000 nm, preferably, the diameter is 200-2000 nm.

3. The heat pipe according to claim 1, characterized in that: The aspect ratio of the nanowire structure is 10 7 :1-10 1 :1, preferably, the aspect ratio is 10 6 :1-10 4 :

1.

4. The heat pipe according to claim 1, characterized in that: The metal connection layer is a low melting point metal plating layer, and the melting point is 25°C-400°C.

5. The heat pipe according to claim 1, characterized in that: The metal aerogel with a nanowire structure is made of a ferromagnetic metal or metal alloy; preferably, the metal aerogel with a nanowire structure is made of nickel, cobalt, iron, steel or an alloy thereof; preferably, the porosity of the metal aerogel with a nanowire structure is 30%-99%, and preferably, the metal aerogel with a nanowire structure has elastic properties.

6. The heat pipe according to claim 4, characterized in that: The low melting point metal is at least one of indium, tin, bismuth, gallium and zinc; the thickness of the low melting point metal coating is 50nm-1mm.

7. The heat pipe according to claim 1, characterized in that: When the liquid working medium contains water and the standard electrode potential of the metal on the inner surface of the heat pipe is lower than 0V, the inner surface of the heat pipe in contact with the water also has a layer of metal with a standard electrode potential greater than 0V.

8. A method for preparing a heat pipe according to any one of claims 1 to 7, characterized in that: The steps include: S1, preparing a metal aerogel with a nanowire structure having a predetermined orientation as a liquid wick; S2, forming a metal connection layer on the inner wall of the metal shell of a predetermined shape; S3, inserting the metal aerogel into the metal shell in such a way that the length direction of the nanowire structure of the metal aerogel is consistent with the length direction of the heat pipe, and then heating the heat pipe to a temperature above the melting point of the metal connecting layer so that the metal aerogel is fixed to the inner wall of the metal shell; S4, sealing one end of the heat pipe, filling it with liquid working medium and evacuating it; S5. Seal the other end of the heat pipe.

9. The method for preparing a heat pipe according to claim 8, characterized in that: In step S1, the metal aerogel is prepared by a sol-gel method combined with a magnetic field induction step; preferably, the metal aerogel is nickel aerogel, and its preparation comprises the following steps: (1) preparing a solution A of 0.01-10M nickel salt, 0.01-10M complexing agent, and 0.01-10mM H2PtCl6; wherein, preferably, the nickel salt is at least one of NiCl2, nickel sulfate, nickel acetate, and nickel nitrate, the complexing agent is citrate or an organic acid, preferably the citrate is Na3C6H5O7, and the organic acid is at least one of ethylenediaminetetraacetic acid and tartaric acid; (2) preparing a reducing agent and deionized water into a solution B, wherein the concentration of the reducing agent in the solution B is 0.1-30 vol.%, wherein preferably, the reducing agent is at least one of hydrazine hydrate, oxalic acid, sodium borohydride, and sodium hypophosphite; (3) adjusting the pH of solution A and solution B to 7-14 respectively; (4) preheating solution A and solution B to a reaction temperature respectively; preferably, the reaction temperature is 30-100° C.; (5) mixing solution A and solution B in a mold of a predetermined shape according to a molar ratio of the nickel salt in solution A to the reducing agent in solution B of 2:1-1:20, and placing the mold in a water bath to maintain the temperature at the reaction temperature; (6) placing the entire reaction device of step (5) into a Helmholtz coil, ensuring that the mold containing solution A and solution B is at the center of the Helmholtz coil, applying power and adjusting the current to adjust the magnetic induction intensity to a predetermined value, and reacting to obtain a nickel aerogel having a predetermined orientation; preferably, the magnetic induction intensity is 50-2000 Gs, and the reaction time is 1-120 min; more preferably, the magnetic induction intensity is 50-500 Gs, and the reaction time is more preferably 50-120 min; (7) The obtained nickel aerogel is repeatedly washed with deionized water until the pH of the cleaning solution is neutral, and then the washed nickel aerogel is air-dried to obtain a nickel aerogel of a predetermined shape and size.

10. The method for preparing a heat pipe according to claim 8, characterized in that: Step S2 includes the following steps: S21. Clean the inner wall surface of the metal casing; S22. Use a plating solution containing the metal elements in the metal connecting layer to plate a coating of a predetermined thickness on the inner surface of the metal shell. Preferably, the plating method is at least one of chemical plating, electroplating, and coating. More preferably, the plating method is chemical plating. S23, washing and drying the product obtained in step S22.

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