CN115060099A - Micro-nano multi-scale structure steam chamber and manufacturing method thereof - Google Patents

Abstract

The present invention provides a micro-nano multi-scale structure steam chamber and a manufacturing method thereof. The micro-nano multi-scale structure steam chamber comprises an evaporation end, a condensation end and a plurality of support columns located between the evaporation end and the condensation end, and Two ends of the support column are respectively connected with the evaporation end and the condensation end, the evaporation end and the condensation end form a steam cavity, and the steam cavity is filled with a heat transfer medium; wherein, the evaporation end and the condensation end The surface of the side of the end close to the condensation end has a super-hydrophilic micro-nano multi-scale structure, and the surface of the side of the condensation end close to the evaporation end has a super-hydrophilic nanostructure. The surface of the condensation end of the micro-nano multi-scale structure steam cavity provided by the invention has a super-hydrophilic nano-structure, and in a microgravity environment, the condensed heat transfer working medium can be efficiently refluxed by relying on the strong capillary wicking action of the super-hydrophilic nano-structure , and the multi-support column design scheme can provide reliable bearing capacity under high pressure environment.

Description

Micro-nano multi-scale structure steam chamber and manufacturing method thereof

technical field

The invention relates to the technical field of heat transfer, in particular to a micro-nano multi-scale structure steam cavity and a manufacturing method thereof.

Background technique

With the continuous development of high-end equipment such as microelectronic equipment, radar, laser weapons and nuclear power plants towards high integration and high power, the power of equipment has gradually developed from the current kilowatt level to 10,000 watts, and may even reach megawatts in the future class. If the instantaneous high-density heat flow generated by its power heat source cannot be dissipated in time, it will easily cause equipment failure or failure. The vapor chamber can utilize the huge latent heat provided by the dual phase transition of evaporation/boiling and condensation to achieve effective evacuation of high heat flux density. At present, the vapor chamber has been applied to the fields of chip heat dissipation and integrated microelectronic devices.

With the continuous development of my country's aerospace technology, space-borne electronic components and space-based weapons are also facing severe heat dissipation problems. Most of the steam chambers in the prior art rely on the hydrophilic properties of the evaporating end to improve the limit of boiling heat transfer, and rely on the hydrophobic properties of the condensation end to promote the condensation of droplets and then rely on gravity to drop to achieve enhanced heat transfer. The higher vapor pressure in the cavity needs to be considered, and its support structure is relatively simple. However, due to the microgravity environment and extremely cold and extremely hot phenomena in the space, the hydrophobic condensing surface cannot achieve effective working fluid backflow, and the high-pressure environment in the cavity requires a reliable support structure.

SUMMARY OF THE INVENTION

The problem to be solved by the present invention is to provide a steam chamber that can be applied to a space device to dissipate heat and can provide reliable support.

In order to solve at least one aspect of the above problems, the present invention provides a micro-nano multi-scale structure steam chamber, comprising an evaporation end, a condensation end and a plurality of support columns located between the evaporation end and the condensation end, and the Two ends of the support column are respectively connected with the evaporation end and the condensation end, the evaporation end and the condensation end form a steam chamber, and the steam chamber is filled with a heat transfer medium; wherein, the evaporation end The surface of the side close to the condensation end has a super-hydrophilic micro-nano multi-scale structure, and the surface of the side of the condensation end close to the evaporation end has a super-hydrophilic nanostructure.

Preferably, the super-hydrophilic micro-nano multi-scale structure includes a micro-structure and a super-hydrophilic nano-structure located on the surface of the micro-structure; wherein the micro-structure includes micro-channels, micro-pillars and micro-pores, and the micro-structure The size of the superhydrophilic nanostructure is from several tens of micrometers to several millimeters, and the superhydrophilic nanostructure includes nanopillars, nanopores and nanorods, and the size of the superhydrophilic nanostructure is several to several hundreds of nanometers.

Preferably, the microstructure is a pyramid array microstructure, and the feature size of the pyramid array microstructure is 100 μm and the period is 1 mm.

Preferably, the surface of the support column has superhydrophilic nanostructures.

Preferably, the area of the steam chamber is 100cm ² to 1m ² , the side length or diameter of the support column is 2.5-3.5mm, the distance between the two support columns is 6-10mm, and the evaporation end And the thickness of the condensation end is 1-2mm, the distance between the evaporation end and the condensation end is 0.5-2.5mm, and the overall thickness of the steam chamber is less than or equal to 5mm.

Preferably, the heat transfer working medium is liquid ammonia.

Preferably, the materials of the evaporation end, the condensation end and the support column include aluminum alloy or magnesium alloy.

In the present invention, a plurality of support columns are arranged between the evaporation end and the condensation end, and the two ends of the support columns are respectively connected with the evaporation end and the condensation end, so as to enhance the high-pressure bearing capacity of the steam chamber in the space environment; for the microgravity space environment, The surface of the evaporation end has a super-hydrophilic micro-nano multi-scale structure, in which the micro-nano multi-scale structure can increase more active nucleation sites for bubbles, while the super-hydrophilicity can realize the rapid replenishment of the liquid in the heat-drying area, and can also provide Liquid transport channel, so as to achieve synergistic enhancement of heat transfer coefficient and boiling heat transfer limit. The heat transfer working medium after being heated and evaporated at the evaporation end is transported to the condensation end. Because the surface of the condensation end has super hydrophilic nanostructures, the evaporated The heat transfer working medium is condensed on the superhydrophilic nanostructure, and can rely on the strong capillary wicking effect of the superhydrophilic nanostructure to achieve the purpose of efficient reflux of the condensed heat transfer working medium, so it can be realized in a microgravity space environment. Efficient heat transfer; the micro-nano multi-scale structure steam chamber provided by the present invention can ensure that the steam chamber can achieve effective working fluid backflow in microgravity and a space environment with extremely cold and extremely hot phenomena, and can provide reliable bearing in a high-pressure environment force.

Another embodiment of the present invention provides a method for fabricating the above-mentioned micro-nano multi-scale structure steam cavity. The micro-structure is fabricated on the surface of the boiling heat transfer material by the micro-structure fabrication method, and then the super-hydrophilic nano-structure fabrication method is used in the above-mentioned fabrication method. On the basis of the microstructure described above, a superhydrophilic nanostructure is obtained, and an evaporation end is obtained, and the surface of the evaporation end has a superhydrophilic micro-nano multiscale structure; the superhydrophilic nanostructure is directly prepared on the surface of the boiling heat transfer material by the superhydrophilic nanostructure manufacturing method. A superhydrophilic nanostructure is obtained, and a condensation end is obtained, and the surface of the condensation end has a superhydrophilic nanostructure.

Preferably, the microstructure fabrication method includes micro-imprinting, rolling, micro-milling or micro-electric sparking.

Preferably, the superhydrophilic nanostructure fabrication method includes laser etching, chemical etching or electrochemical treatment.

Compared with the prior art, the manufacturing method of the micro-nano multi-scale structure steam cavity provided by the present invention has the same beneficial effects as the micro-nano multi-scale structure steam cavity, which will not be repeated here.

Description of drawings

FIG. 1 is a schematic structural diagram of a micro-nano multi-scale structure steam chamber in an embodiment of the present invention;

Fig. 2 is the wettability analysis diagram of different steam chamber structures in the embodiment of the present invention;

FIG. 3 is an analysis diagram of the steam chamber load in the embodiment of the present invention.

Description of reference numbers:

1. Evaporating end; 2. Condensing end; 3. Supporting column; 4. Heat transfer medium.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, specific embodiments of the present invention will be described in detail below.

It should be noted that the features in the embodiments of the present invention may be combined with each other without conflict. The meanings of the terms "comprising", "including", "containing", "having" are non-limiting, that is, other steps and other ingredients may be added that do not affect the result. The above terms cover the terms "consisting of" and "consisting essentially of". Unless otherwise specified, materials, equipment and reagents are all commercially available. In addition, it should be noted that the direction indicated by the hollow arrow in the figure is the hot steam path, and the square indicated by the solid arrow is the heat transfer working medium return path.

The embodiment of the present invention provides a micro-nano multi-scale structure steam chamber, including an evaporation end 1, a condensation end 2, and a plurality of support columns 3 located between the evaporation end 1 and the condensation end 2, and the support columns The two ends of 3 are respectively connected with the evaporation end 1 and the condensation end 2, the evaporation end 1 and the condensation end 2 form a steam chamber, and the steam chamber is filled with a heat transfer medium 4; The surface of the side close to the evaporation end 1 and the condensation end 2 has a super-hydrophilic micro-nano multi-scale structure, and the surface of the side of the condensation end 2 close to the evaporation end 1 has a super-hydrophilic nanostructure.

Wherein, the super-hydrophilic micro-nano multi-scale structure on the surface of the evaporation end 1 includes a microstructure and a super-hydrophilic nanostructure on the surface of the microstructure; wherein, the microstructure includes microchannels, micropillars and microstructures Pores, the size of the microstructures is tens of micrometers to several millimeters, such as 10 micrometers to 10 millimeters, the superhydrophilic nanostructures include nanopillars, nanopores and nanorods, and the size of the superhydrophilic nanostructures is A few to several hundred nanometers, such as 1 nanometer to 1000 nanometers.

Exemplarily, the microstructure is a pyramid array microstructure, and the feature size of the pyramid array microstructure is 100 μm and the period is 1 mm.

The micro-nano multi-scale structure in the super-hydrophilic micro-nano multi-scale structure can provide active nucleation sites for more bubbles, and because of its super-hydrophilicity, it can realize rapid replenishment of liquid in the heat-dried area. In addition, The microstructure in the superhydrophilic micro-nano multiscale structure can also provide a liquid transport channel, when the evaporation end 1 is heated, especially under high heat flux density, it can pass through the superhydrophilic surface of the evaporation end 1. The micro-nano multi-scale structure achieves synergistic enhancement of heat transfer coefficient and boiling heat transfer limit.

The superhydrophilic nanostructures on the surface of the condensation end 2 include nanopillars, nanopores and nanorods, and the size of the superhydrophilic nanostructures is several to several hundred nanometers, for example, 1 nanometer to 1000 nanometers.

The surface of the side close to the evaporation end 1 and the condensation end 2 has a super-hydrophilic micro-nano multi-scale structure, and the surface of the side of the condensation end 2 close to the evaporation end 1 has a super-hydrophilic nanostructure; , the super-hydrophilic micro-nano multi-scale structures of the evaporation end 1 and the super-hydrophilic nano-structures on the surface of the condensation end 2 are both located inside the steam chamber.

In addition, the surface of the support column 3 has a super-hydrophilic nanostructure. By arranging superhydrophilic nanostructures on the surface of the support column 3, the efficiency of condensation and reflux can be improved. The superhydrophilic nanostructures on 3 quickly reflow to the surface of the evaporation end 1.

Specifically, the area of the steam chamber is 100cm ² to 1m ² , the side length or diameter of the support column 3 is 2.5-3.5mm, and the distance between the two support columns 3 is 6-10mm. The thickness of the evaporation end 1 and the condensation end 2 is 1-2 mm, the distance between the evaporation end 1 and the condensation end 2 is 0.5-2.5 mm, and the overall thickness of the steam chamber is less than or equal to 5 mm. In order to be applicable to the space environment, the steam cavity has a large area, ranging from 100 cm ² to 1 m ² ; since the heat transfer working medium 4 can generate vapor pressure under high heat flux density, when the heat transfer working medium 4 is liquid When ammonia is used, the vapor pressure can reach up to 5.6MPa, the support column 3 can be a square column or a cylinder, its side length or diameter is 2.5-3.5mm, and the distance between the two support columns 3 is 6 -10mm, so as to provide sufficient bearing capacity for the steam chamber and avoid high-pressure deformation failure of the steam chamber.

The heat transfer working medium 4 in the steam chamber is preferably liquid ammonia, which has good compatibility with the steam chamber, large latent heat of phase change, and low steam density.

Since the steam chamber provided in the embodiment of the present invention is applied to a space environment, the evaporation end 1 , the condensation end 2 and the support column 3 are all made of low-density and lightweight materials, such as aluminum alloy or magnesium alloy.

When the steam chamber is working, the evaporation end 1 is heated, and the heat transfer working medium 4 is evaporated to generate hot steam. Since the surface of the evaporation end 1 has a super-hydrophilic micro-nano multi-scale structure, the synergistic enhancement of the heat transfer coefficient and the boiling heat transfer limit can be achieved. , and can realize the rapid replenishment of the liquid in the heated and dry area. After the hot steam evaporates to the condensation end 2, it is converted into a liquid heat transfer medium 4 again through the condensation of the condensation end 2, and passes through the superhydrophilic nanostructure on the surface of the condensation end 2. The powerful capillary wicking effect realizes the efficient reflux of the condensed heat transfer working medium 4, and the super-hydrophilic nanostructure on the surface of the support column 3 can further improve the reflux efficiency of the heat transfer working medium 4, so as to realize the high efficiency in the microgravity space. It can run stably in the environment, and the support column 3 ensures that the steam chamber has a good bearing capacity during operation.

Another embodiment of the present invention provides a method for fabricating the above-mentioned micro-nano multi-scale structure steam cavity. The micro-structure is fabricated on the surface of the boiling heat transfer material by the micro-structure fabrication method, and then the super-hydrophilic nano-structure fabrication method is used in the above-mentioned fabrication method. On the basis of the microstructure, a superhydrophilic nanostructure is obtained to obtain an evaporation end 1, and the surface of the evaporation end 1 has a superhydrophilic micro-nano multiscale structure; the superhydrophilic nanostructure manufacturing method is directly used in the boiling heat transfer material. A superhydrophilic nanostructure is prepared on the surface, and a condensation end 2 is obtained, and the surface of the condensation end 2 has a superhydrophilic nanostructure.

Wherein, the microstructure manufacturing method includes micro-imprinting, rolling, micro-milling or micro-electric sparking, and the super-hydrophilic nanostructure manufacturing method includes laser etching, chemical etching or electrochemical treatment.

Exemplarily, a micro-imprinting method is used to obtain a microstructure on the surface of an aluminum alloy material. The micro-imprinting parameters are: an imprinting temperature of 350° C., a forming pressure of 156 MPa, an imprinting speed of 0.005 mm/s, a pressure holding time of 300 s, and then a pressure of 156 MPa. The aluminum alloy material with microstructure is processed by high-pressure hydrothermal method. The parameters of high-pressure hydrothermal method are: temperature 200℃, pressure 1.56MPa, treatment time 120min, and the evaporation end 1 is obtained, and the surface of the evaporation end 1 has super hydrophilic properties. Micro-nano multi-scale structure; the super-hydrophilic nanostructure is directly obtained on the surface of the aluminum alloy material by the nanosecond pulse laser processing method, and the condensation end 2 is obtained, wherein the parameters of the nano-pulse laser processing method are: laser power 80W, scanning speed 100mm/ s, the pulse frequency is 10 kHz, and the filling spacing is 50 μm.

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In the following examples, the experimental methods without specific conditions are generally in accordance with the conditions suggested by the manufacturer.

Example

1.1. First, the microstructure was obtained on the surface of 6063 aluminum alloy material by micro-imprinting method. The micro-imprinting parameters were: imprinting temperature 350℃, forming pressure 156MPa, imprinting speed 0.005mm/s, holding time 300s, and then passed The 6063 aluminum alloy material with microstructure is treated by high pressure hydrothermal method. The parameters of high pressure hydrothermal method are: temperature 200℃, pressure 1.56MPa, treatment time 120min, and the evaporation end is obtained, and the surface of the evaporation end has super-hydrophilic micro-nano poly scale structure;

1.2. The super-hydrophilic nanostructure is directly obtained on the surface of 6063 aluminum alloy material by nanosecond pulse laser processing method, and the condensation end is obtained. The parameters of nano pulse laser processing method are: laser power 80W, scanning speed 100mm/s, pulse frequency 10kHz, fill spacing 50μm;

1.3. Assemble the evaporating end and the condensing end into a steam chamber, and use a plurality of supporting columns to connect the evaporating end and the condensing end in the steam chamber to obtain a steam chamber with an area of 100 cm ² , and the height of the steam chamber is 1.5 mm, wherein the evaporation The thickness of the end and the condensation end are both 1.6mm, the support column is cylindrical with a diameter of 3mm, the spacing between the two support columns is 7mm, the microstructure on the evaporation end is a pyramid array microstructure, the feature size is 100μm, and the period is 1mm.

Experimental example 1

5 μL of pure water was dropped on the surface of the initial 6063 aluminum alloy material, the evaporation end in the example, and the condensation end in the example, respectively, to measure the contact angle of water, and to test the wettability. The result is shown in Figure 2:

Fig. 2(a) is the wettability result of the surface of the 6063 aluminum alloy material, Fig. 2(b) is the wettability result of the evaporation end surface in the embodiment, and Fig. 2(c) is the condensation end surface in the embodiment It can be seen that the water on the surface of the 6063 aluminum alloy material has a certain contact angle, while in the example, the pure water at the evaporation end and the condensation end can be completely flattened, and the contact angle is 0, indicating the implementation of the present invention. The evaporating end and the condensing end prepared in this example are superhydrophilic.

Experimental example 2

The stress of the steam chamber in the embodiment is simulated and analyzed. Since the pressure bearing model of the steam chamber is an axisymmetric model, the 1/4 model of the steam chamber in the embodiment is numerically simulated and verified, and the pressure in the chamber is set to 5.6MPa. The result is shown in Figure 3:

Among them, Figure 3(a) is the overall Mises stress distribution of the steam chamber, and Figure 3(b) is the microstructure of the evaporation end and the local Mises stress distribution of the support column. The overall maximum Mises stress of the steam chamber is 52.9MPa, and the microstructure The local maximum Mises stress of the agent support column is 62.1 MPa, which is smaller than the yield strength of aluminum alloy and magnesium alloy and other materials, which can meet the bearing requirements of the space environment, and ensure that when the pressure in the cavity is 5.6 MPa, any position of the steam chamber will not be damaged. There is plastic deformation.

Although the present disclosure is disclosed above, the scope of protection of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims (10)

1. A steam cavity with a micro-nano multi-scale structure is characterized by comprising an evaporation end (1), a condensation end (2) and a plurality of supporting columns (3) located between the evaporation end (1) and the condensation end (2), wherein two ends of each supporting column (3) are respectively connected with the evaporation end (1) and the condensation end (2), the evaporation end (1) and the condensation end (2) form a steam cavity, and a heat transfer medium (4) is filled in the steam cavity;

the surface of one side, close to the evaporation end (1) and the condensation end (2), of the evaporation end has a super-hydrophilic micro-nano multi-scale structure, and the surface of one side, close to the condensation end (2), of the condensation end has a super-hydrophilic nano structure.

2. The vapor chamber with the micro-nano multi-scale structure as claimed in claim 1, wherein the super-hydrophilic micro-nano multi-scale structure comprises a micro-structure and a super-hydrophilic nano-structure on the surface of the micro-structure; the super-hydrophilic nano structure comprises nano columns, nano holes and nano rods, and the size of the super-hydrophilic nano structure is several to several hundred nanometers.

3. The micro-nano multi-scale structure vapor chamber as claimed in claim 2, wherein the microstructure is a pyramid array microstructure, the feature size of the pyramid array microstructure is 100 μm, and the period is 1 mm.

4. The micro-nano multi-scale structure vapor chamber according to claim 1, wherein the surface of the support column (3) has super-hydrophilic nano-structures.

5. The micro-nano multi-scale structure vapor chamber as claimed in claim 1, wherein the area of the vapor chamber is 100cm ² ～1m ² The side length or the diameter of the supporting columns (3) is 2.5-3.5mm, the distance between the two supporting columns (3) is 6-10mm, the thickness of the evaporation end (1) and the condensation end (2) is 1-2mm, and the evaporation end (1) and the condensation end (2) are connected in seriesThe distance is 0.5-2.5mm and the overall thickness of the steam chamber is less than or equal to 5 mm.

6. The micro-nano multi-scale structured vapor chamber according to claim 1, wherein the heat transfer medium (4) is liquid ammonia.

7. The micro-nano multi-scale structure vapor chamber as claimed in claim 1, wherein the evaporation end (1), the condensation end (2) and the support column (3) are made of aluminum alloy or magnesium alloy.

8. The manufacturing method of the vapor chamber with the micro-nano multi-scale structure as claimed in any one of claims 1 to 7, characterized in that a microstructure is manufactured on the surface of a boiling heat transfer material by a microstructure manufacturing method, and then a super-hydrophilic nanostructure is manufactured on the basis of the microstructure by a super-hydrophilic nanostructure manufacturing method to obtain an evaporation end (1), wherein the surface of the evaporation end (1) is provided with the super-hydrophilic micro-nano multi-scale structure;

the super-hydrophilic nano structure is directly prepared on the surface of the boiling heat transfer material by the super-hydrophilic nano structure manufacturing method, so that the condensation end (2) is obtained, and the surface of the condensation end (2) is provided with the super-hydrophilic nano structure.

9. The method for manufacturing a vapor chamber with a micro-nano multi-scale structure according to claim 8, wherein the method for manufacturing the micro-structure comprises micro-embossing, rolling, micro-milling or micro-electric spark.

10. The method for manufacturing a vapor chamber with a micro-nano multi-scale structure according to claim 8, wherein the method for manufacturing the super-hydrophilic nano structure comprises laser etching, chemical etching or electrochemical treatment.

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