Direct cooling plate with double conveying modes and preparation method thereof

Abstract

The invention discloses a direct cooling plate with double conveying modes and a preparation method thereof.The direct cooling plate comprises an upper base plate and a lower base plate, one of the upper base plate and the lower base plate is provided with a groove, and the upper base plate and the lower base plate are matched to seal the groove to form a runner; a micro-communication groove is formed in the wall surface of the flow channel. And the cross section of the micro groove is one or a combination of more of an inverted V shape, an inverted omega shape, an inverted trapezoid and a rectangle. The flow channel in the direct cooling plate obtained by the processing method not only depends on the macroscopic shape of the flow channel for flowing, but also realizes the wall surface conveying of a refrigerant through a specific inner wall structure. According to the wall conveying function, microstructures such as micro grooves, micro holes or micro protrusions can be formed on the inner walls of the flow channels, so that the contact area between a refrigerant and the inner walls is increased, and the heat exchange effect is enhanced. Meanwhile, the microstructures can effectively guide refrigerants to be evenly distributed in the flow channel, formation and gathering of bubbles are reduced, the air blocking phenomenon is avoided, and therefore efficient and stable operation of a cooling system is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of heat exchange cooling technology, and in particular to a direct cooling plate with a dual-transport mode and a preparation method thereof. Background Art

[0002] With the rapid development of automobile electrification, the power consumption of on-board electronic equipment continues to increase, and the heat dissipation problem is becoming increasingly serious. In particular, with the increase in battery capacity and charging speed, the heat generated inside the battery has increased significantly, while the space inside the car is limited and the heat dissipation space is also shrinking, resulting in the traditional heat dissipation method being unable to meet the needs of modern cars for efficient heat dissipation. Therefore, it is particularly important to design a more efficient battery heat dissipation system to ensure the safety and reliability of the car during long-term operation.

[0003] Among the existing heat dissipation technologies, liquid cooling plates are widely used as an effective heat dissipation method. However, with the popularization of automobile fast charging technology, the heat generated during the charging process rises sharply in a very short time, and the heat dissipation capacity of traditional liquid cooling plates begins to appear insufficient. Traditional direct cooling plate heat dissipation technology usually processes a simple flow channel structure on the cooling plate and uses the flow of refrigerant in the flow channel to carry away the heat. However, this processing method is relatively simple, focusing mainly on the macroscopic geometry of the flow channel, while not enough consideration is given to the detailed design of the inner wall structure of the flow channel. Although this simple design can provide basic heat dissipation effects in some cases, faced with the increasingly complex heat dissipation needs of high-performance electronic equipment and industrial systems, the limitations of existing direct cooling plates have become more obvious.

[0004] Traditional direct cold plate processing methods usually rely on processes such as milling, etching or stamping, which mainly focus on the shape design of the flow channel, such as straight, curved or serpentine flow channels. Although these flow channel designs can optimize the flow path of the refrigerant to a certain extent, the processing of the inner wall of the flow channel is usually rough and simple, usually presenting a smooth surface. Although this smooth inner wall characteristic can reduce the flow resistance to a certain extent and increase the flow rate of the refrigerant, it also brings the defect that the refrigerant cannot fully contact the inner wall of the flow channel, especially when the refrigerant flow rate is low or the refrigerant is highly sensitive to heat transfer. This design results in limited heat exchange efficiency of the refrigerant in the flow channel, and the cooling effect is difficult to evenly cover the entire inner wall of the flow channel.

[0005] In addition, the lack of an effective turbulent structure on the inner wall of the flow channel may further cause the flow of the refrigerant to stagnate in local areas, thereby increasing the probability of bubble formation. If these bubbles gather in the flow channel, they may form an air plug, which seriously affects the normal flow of the refrigerant and causes a significant decrease in heat dissipation performance. Air plugs not only hinder the circulation of the refrigerant, but also form local overheating areas in the flow channel, further reducing the overall efficiency of the cooling system. Therefore, how to improve the inner wall structure of the flow channel and increase the contact area and heat exchange efficiency between the refrigerant and the flow channel wall has become a key issue in improving the heat dissipation performance of direct cooling plates.

[0006] In order to meet these challenges, developing more complex and sophisticated channel inner wall structure designs is an important direction.

[0007] In summary, as the requirements for heat dissipation efficiency in automobiles continue to increase, the processing methods and designs of traditional direct cooling plates can no longer meet the existing heat dissipation needs. Optimizing the inner wall structure of the flow channel to improve the flow and heat exchange efficiency of the refrigerant will be an important direction for the design of efficient heat dissipation systems in the future. Summary of the invention

[0008] The purpose of the present application is to overcome at least one of the shortcomings of the prior art, and to provide a direct cooling plate with a dual transport mode and a preparation method thereof. The flow channel in the direct cooling plate obtained by the processing method not only relies on the macroscopic shape of the flow channel for flow, but also realizes the wall transport of the refrigerant through a specific inner wall structure. This wall transport function can increase the contact area between the refrigerant and the inner wall and enhance the heat exchange effect by forming microstructures such as microgrooves, micropores or microprotrusions on the inner wall of the flow channel. At the same time, these microstructures can effectively guide the refrigerant to be evenly distributed in the flow channel, reduce the formation and aggregation of bubbles, and avoid air plugging, thereby ensuring the efficient and stable operation of the cooling system.

[0009] To achieve the above-mentioned objectives, in the first aspect, the present application discloses a direct cooling plate with a dual conveying mode, which direct cooling plate includes an upper substrate and a lower substrate, one of the upper substrate and the lower substrate has a groove, and the upper substrate and the lower substrate cooperate to seal the groove to form a flow channel; the wall surface of the flow channel is provided with a micro-channel.

[0010] In some embodiments, the cross-section of the micro groove is one or more combinations of an inverted V-shape, an inverted Ω-shape, an inverted trapezoid, and a rectangle.

[0011] In some embodiments, the micro grooves are aligned with the flow channel.

[0012] In some embodiments, the microgrooves are disposed on the groove surface.

[0013] In a second aspect, the present application discloses a method for preparing a direct cooling plate with a dual conveying mode, the method comprising the following steps:

[0014] Step S1: placing the stamped upper and lower substrates in a pickling solution for pickling treatment respectively to remove oxides and other impurities on the surfaces of the two substrates to ensure that the surfaces of the substrates are clean and free of impurities;

[0015] Step S2: After pickling, the two substrates are taken out from the pickling solution, and the substrates are thoroughly rinsed with deionized water to ensure that the pickling solution and surface residues are completely removed;

[0016] Step S3: Drying the two substrates after the water washing process to ensure that there is no water residue on the surface of the substrates, so as to prepare for the subsequent laser etching process;

[0017] Step S4: selecting suitable laser etching equipment and parameters according to the materials of the upper and lower substrates;

[0018] Step S5: fix the upper and lower substrates on the laser etching workbench respectively to ensure that the substrate surface is flat and without distortion; start the laser etching equipment, and scan the substrate surface line by line according to the preset scanning path to form the required micro-groove structure; the depth of the micro-groove after etching is controlled between 0.01-0.2mm, and the width is controlled between 0.1-0.2mm;

[0019] Step S6: After laser etching is completed, use a dust-free cloth or gas blowing equipment to perform preliminary cleaning on the substrate to remove large particles and dust on the surface. Check the shape and size of the micro grooves to ensure that there are no surface defects caused by uneven etching;

[0020] Step S7: placing the laser-etched substrate into an ultrasonic cleaning device for deep cleaning;

[0021] Step S8: After ultrasonic cleaning, the substrate is rinsed multiple times with deionized water to ensure that there is no chemical residue in the micro grooves;

[0022] Step S9: The upper and lower substrates are immediately dried after being rinsed to ensure that there is no moisture remaining on the substrate surfaces, and the upper and lower substrates are pressed and stacked together and fixed as a whole to form at least one flow channel with a micro-surge groove.

[0023] Furthermore, the substrate can be made of metal materials such as copper, aluminum, stainless steel, etc. These materials have excellent thermal conductivity and are suitable for efficient cooling applications.

[0024] Furthermore, in step S3, the drying method may be hot air drying or vacuum drying. After drying, the surface of the substrate should be dry and clean without water stains and dirt.

[0025] Furthermore, in step S5, multiple scans may be performed during the etching process to ensure the uniformity and accuracy of the micro grooves.

[0026] Furthermore, in step S4, the specific adjustment parameters include laser power, laser frequency, pulse width, spot diameter, and scanning speed.

[0027] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0028] 1. Realize dual delivery mode: Micro-groove structures with various cross-sectional shapes are formed by laser etching, which not only enhances the fluidity of the refrigerant, but also increases the adsorption effect of the refrigerant in the flow channel, realizing the dual delivery mode of flow and adsorption, and significantly improving the heat dissipation performance.

[0029] 2. Optimize the refrigerant contact area: The fine design of the micro grooves enables the refrigerant to fully contact the inner wall of the substrate, improving the heat transfer efficiency and overcoming the problem of insufficient heat dissipation caused by insufficient refrigerant contact in traditional direct cooling plates.

[0030] 3. Prevent the formation of air plugs: The fine micro-groove structure design reduces the risk of refrigerant stagnation and bubble accumulation in the flow channel, effectively preventing the formation of air plugs, ensuring the smooth flow of refrigerant and the stable operation of the direct cooling plate.

[0031] The above-listed beneficial effects are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementations will be further disclosed in the examples or other description parts of this application.

[0032] The above-listed beneficial effects are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementations will be further disclosed in the examples or other description parts of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] After reading the following detailed description in conjunction with the accompanying drawings, you will better understand the various aspects of the present disclosure. The positions, sizes, and ranges of various structures shown in the accompanying drawings sometimes do not represent the actual positions, sizes, and ranges. In the accompanying drawings:

[0034] Figure 1 It is a structural schematic diagram of an embodiment disclosed in the present application under a three-dimensional perspective.

[0035] Figure 2 It is a structural schematic diagram of an embodiment disclosed in the present application from another perspective.

[0036] Figure 3 It is a structural schematic diagram of an embodiment disclosed in the present application from another perspective. DETAILED DESCRIPTION

[0037] The present disclosure will be described below with reference to the accompanying drawings, wherein the accompanying drawings illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in a variety of different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present disclosure more complete and fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0038] It should be understood that the same reference numerals represent the same elements throughout the drawings. In the drawings, the dimensions of certain features may be distorted for clarity.

[0039] It should be understood that the terms used in the specification are only used to describe specific embodiments and are not intended to limit the present disclosure. All terms (including technical terms and scientific terms) used in the specification have the meanings commonly understood by those skilled in the art unless otherwise defined. For the sake of brevity and / or clarity, the techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification.

[0040] The singular forms "a", "said" and "the" used in the specification include plural forms unless clearly indicated. The terms "include", "comprise" and "contain" used in the specification indicate the presence of the claimed features, but do not exclude the presence of one or more other features. The term "and / or" used in the specification includes any and all combinations of one or more of the relevant listed items.

[0041] Example:

[0042] This embodiment describes in detail a method for preparing a flow-adsorption dual transport mode groove refrigerant direct cooling plate with dual transport modes.

[0043] In terms of the specific structure of the direct cooling plate, the core structure of the direct cooling plate includes an upper base plate 1 and a lower base plate 2, wherein the upper base plate 1 has a groove 3, and the lower base plate 2 is a flat plate. By matching the upper base plate 1 and the lower base plate 2, a flow channel 3 of the refrigerant is sealed and formed.

[0044] In order to further improve the heat transfer efficiency of the refrigerant and ensure the stability of the flow channel, a micro-groove structure is set on the wall of the flow channel 3 using laser etching technology.

[0045] In the preparation process of this embodiment, a copper substrate with a thickness of 0.8 mm is first selected as the material of the upper substrate 1 and the lower substrate 2.

[0046] Understandably, copper is known for its excellent thermal conductivity, which can significantly improve the heat transfer efficiency of the refrigerant when the equipment is running at high load.

[0047] To ensure that the substrate surface is clean and free of impurities, the upper substrate 1 and the lower substrate 2 after stamping need to be placed in a 10% volume fraction sulfuric acid solution for pickling. The pickling time is controlled at about 10 minutes, and the pickling temperature is maintained at 40°C to effectively remove oxides and other impurities on the surface. After the pickling is completed, the upper substrate 1 and the lower substrate 2 are taken out of the pickling solution and rinsed with deionized water at 60°C for 5 minutes to ensure that the pickling solution and surface residues are completely removed.

[0048] Next, the upper substrate 1 and the lower substrate 2 that have been washed with water are dried to prevent oxidation from occurring on the surface during the drying process.

[0049] During the specific drying process, the vacuum drying method was selected, the drying temperature was set to 80°C, and the drying time was 15 minutes, in preparation for the subsequent laser etching process.

[0050] In the laser etching process, a laser is used to precisely etch the upper substrate 1 and / or the lower substrate 2. The process parameters of the laser etching are as follows: the laser power is set to 50W, the laser frequency is 200kHz, the pulse width is 7ps, the spot diameter is controlled at 20μm, and the scanning speed is set to 1000mm / s.

[0051] The upper substrate 1 and / or the lower substrate 2 are fixed on the etching workbench to ensure that the surface is flat and free of distortion. The laser etching process scans the surface of the upper substrate 1 and / or the lower substrate 2 line by line according to the preset scanning path to form a micro-groove structure of an inverted "V" shape and a rectangular combination. In order to ensure the uniformity and accuracy of the micro-grooves, the etching process is scanned three times, and the depth of the final micro-groove is controlled at 0.1 mm and the width is 0.15 mm.

[0052] After the laser etching is completed, the upper substrate 1 and the lower substrate 2 need to be cleaned. First, use a dust-free cloth to preliminarily clean the surface of the upper substrate 1 and the lower substrate 2 to remove large particles and dust on the surface. Then, put the upper substrate and the lower substrate into an ultrasonic cleaning device, set the cleaning frequency to 40kHz, and the cleaning time to 10 minutes to ensure that all residues inside the micro grooves are completely removed.

[0053] After cleaning, the upper substrate 1 and the lower substrate 2 are rinsed several times with deionized water at 50°C to completely remove the chemicals and impurities used in the cleaning process. Then, vacuum drying is performed again, with the temperature set at 80°C for 10 minutes to ensure that the substrate surface is completely dry in preparation for the subsequent brazing process.

[0054] After cleaning and drying, the upper substrate 1 and the lower substrate 2 are fixed by a brazing process. For example, silver-based solder is used in the brazing process because it has excellent wettability and a low melting point, and can achieve a firm connection of the substrates at a lower temperature while maintaining the original physical properties of the copper substrate. First, the solder paste is evenly applied on the bonding surface of the upper and lower substrates, and then the two substrates are stacked and fixed.

[0055] For example, the heating temperature of the brazing furnace is set to 650°C and the holding time is 10 minutes to ensure that the brazing material fully flows between the bonding surfaces and forms a solid metallurgical bond with the copper substrate. After brazing, the substrate is slowly cooled to room temperature to avoid deformation or cracks caused by internal stress caused by rapid cooling.

[0056] After the brazing process is completed, the joint parts are strictly inspected to ensure that the brazing is uniform and complete without cracks, pores or incomplete penetration. Finally, the upper substrate 1 and the lower substrate 2 are firmly combined to form a direct cooling plate structure with high thermal conductivity and durability. The integrity and sealing of the micro-groove flow channel formed by laser etching are effectively guaranteed, thereby significantly improving the heat transfer efficiency of the refrigerant.

[0057] In order to fully verify the advantages of the laser-etched flow-adsorption dual transport mode groove refrigerant direct cooling plate described in this embodiment in terms of heat exchange efficiency and prevention of dry burning, a detailed comparative test was conducted. The following are the specific test process, parameters, methods, steps and data results.

[0058] The purpose of the test is to verify the advantages of the direct cooling plate of the present application in cooling speed and heat exchange rate by comparing the cooling effect of the direct cooling plate of the present application with that of the existing direct cooling plate under the same conditions.

[0059] Test material: 1.5 kg iron block, initial temperature: 80°C, two cold plates with the same size of 100 mm × 100 mm.

[0060] Test equipment: Temperature sensor, used to measure the temperature change of the iron block or base block. Timer, used to record the time required for the iron block or base block to reach the target temperature. Refrigerant circulation system, used to provide refrigerant with constant flow and temperature to ensure the cooling effect of the cold plate.

[0061] Test conditions: refrigerant type R134a, cold plate initial temperature 5°C, refrigerant flow rate: 0.5 m / s, cold plate area 0.01 m2, specific heat capacity of iron: 450 J / kg·°C, target temperature: 30°C

[0062] Test steps: Heat a 1.5 kg iron block to 80°C and fix a temperature sensor in the center of the iron block to monitor temperature changes. Place the cold plate in contact with the iron block to ensure good thermal contact between the two. Start the refrigerant circulation system to allow the refrigerant to flow through the cold plate at the set flow rate and temperature. Start the timer and record the initial temperature of the iron block at 80°C; continue to monitor the temperature of the iron block until the temperature drops to the target temperature of 30°C; record the time required for the iron block to drop from 80°C to 30°C.

[0063] Test results:

[0064] Cold plate type Number of tests Cooling time (seconds) Heat absorbed (joules) Heat transfer rate (W) Direct cooling plate of this application 1 145 33750 232.76 2 148 33750 227.36 3 146 33750 231.16 average value 146.33 33750 230.43 Existing direct cooling plate 1 185 33750 182.43 2 188 33750 179.52 3 186 33750 181.18 average value 186.33 33750 181.71

[0065] It should be understood that the amount of heat absorbed by the iron block is: 1.5 kg x 450 joules / kg·degrees Celsius x (80°C - 30°C) = 33750 joules

[0066] The calculation formula for the average heat transfer rate of the direct cooling plate is: heat transfer rate = cooling time / absorbed heat

[0067] The test results show that the direct cooling plate of the present application has a higher heat exchange rate under the same conditions. Specifically, the average heat exchange rate of the direct cooling plate of the present application is 230.43 watts, while the heat exchange rate of the existing direct cooling plate is 181.71 watts. The heat exchange rate has increased by about 26.8%, proving that the technology of the present application has significant advantages in cooling speed and heat exchange performance.

[0068] Although the exemplary embodiments of the present disclosure have been described, it should be understood by those skilled in the art that various changes and modifications can be made to the exemplary embodiments of the present disclosure without departing from the spirit and scope of the present disclosure in essence. Therefore, all changes and modifications are included in the scope of protection of the present disclosure as defined by the claims. The present disclosure is defined by the appended claims, and the equivalents of these claims are also included.

Claims

1. A direct cooling plate with dual conveying mode, characterized in that: The direct cooling plate comprises an upper base plate and a lower base plate, one of the upper base plate and the lower base plate has a groove, and the upper base plate and the lower base plate cooperate to seal the groove to form a flow channel; the wall surface of the flow channel is provided with micro grooves.

2. A direct cooling plate with dual conveying mode as claimed in claim 1, characterized in that: The cross section of the micro groove is one or more combinations of an inverted V shape, an inverted Ω shape, an inverted trapezoid, and a rectangle.

3. A direct cooling plate with dual conveying mode as claimed in claim 1, characterized in that: The micro grooves are in the same direction as the flow channel.

4. A direct cooling plate with dual conveying mode as claimed in claim 1, characterized in that: The micro grooves are arranged on the groove surface.

5. A method for preparing a direct cooling plate with a dual conveying mode as claimed in claim 1, characterized in that: The method comprises the following steps: Step S1: placing the stamped upper and lower substrates in a pickling solution for pickling treatment respectively to remove oxides and other impurities on the surfaces of the two substrates to ensure that the surfaces of the substrates are clean and free of impurities; Step S2: After pickling, the two substrates are taken out from the pickling solution, and the substrates are thoroughly rinsed with deionized water to ensure that the pickling solution and surface residues are completely removed; Step S3: Drying the two substrates after the water washing process to ensure that there is no water residue on the surface of the substrates, so as to prepare for the subsequent laser etching process; Step S4: selecting appropriate laser etching equipment and parameters according to the materials of the upper and lower substrates; Step S5: fix the upper and lower substrates on the laser etching workbench respectively to ensure that the substrate surface is flat and without distortion; start the laser etching equipment, and scan the substrate surface line by line according to the preset scanning path to form the required micro-groove structure; the depth of the micro-groove after etching is controlled between 0.01-0.2mm, and the width is controlled between 0.1-0.2mm; Step S6: After laser etching is completed, use a dust-free cloth or gas blowing equipment to perform preliminary cleaning on the substrate to remove large particles and dust on the surface. Check the shape and size of the micro grooves to ensure that there are no surface defects caused by uneven etching; Step S7: placing the laser-etched substrate into an ultrasonic cleaning device for deep cleaning; Step S8: After ultrasonic cleaning, the substrate is rinsed multiple times with deionized water to ensure that there is no chemical residue in the micro grooves; Step S9: The upper and lower substrates are immediately dried after being rinsed to ensure that there is no moisture remaining on the substrate surfaces, and the upper and lower substrates are pressed and stacked together and fixed as a whole to form at least one flow channel with a micro-surge groove.

6. A method for preparing a direct cooling plate with a dual conveying mode as claimed in claim 5, characterized in that: In step S3, the drying method may be hot air drying or vacuum drying. After drying, the surface of the substrate should be dry and clean without water stains and stains.

7. A method for preparing a direct cooling plate with a dual conveying mode as claimed in claim 5, characterized in that: In step S5, multiple scans may be performed during the etching process to ensure the uniformity and accuracy of the micro grooves.

8. A method for preparing a direct cooling plate with a dual conveying mode as claimed in claim 5, characterized in that: In step S4, specific adjustment parameters include laser power, laser frequency, pulse width, spot diameter, and scanning speed.

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