Double-conveying refrigerant direct cooling plate with diffusion wall surface and preparation method of double-conveying refrigerant direct cooling plate

Abstract

The invention discloses a double-conveying refrigerant direct cooling plate with a diffusion wall surface and a preparation method thereof, the direct cooling plate comprises an upper base plate and a lower base plate which are made of aluminum alloy, the upper base plate and / or the lower base plate are / is internally provided with a linear groove, and the upper base plate and the lower base plate are matched to seal the linear groove to form a plurality of linear runners; the inner wall surface of the linear flow channel is provided with a micro groove which is arranged along the linear flow channel in the same direction, the depth of the micro groove is controlled to be 0.5-2mm, the inner wall surface of the linear flow channel is provided with a spiral capillary conveying groove, the depth of the capillary conveying groove is controlled to be 0.01-0.2 mm, and the width of the capillary conveying groove is controlled to be 0.1-0.2 mm. According to the direct cooling plate, the complicated capillary micro-grooves are etched in the high aluminum alloy plate, so that the fine treatment of the inner wall of the runner is realized. The etching surface not only can increase the contact area between the refrigerant and the wall surface of the flow channel, but also can improve the transmission efficiency of the refrigerant through the capillary action, so that the overall heat exchange effect is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of refrigerant direct cooling plates, specifically a dual-transport refrigerant direct cooling plate with a diffusion wall and a preparation method thereof. The refrigerant direct cooling plate enhances the refrigerant adsorption and flow properties through etching technology, thereby improving the heat dissipation efficiency and being more suitable for the heat dissipation requirements of electric vehicle battery systems. Background Art

[0002] Among the existing heat dissipation technologies, liquid cooling plates, as an effective heat dissipation method, have been widely used in the fields of electronic equipment and automobiles. Especially in the context of automobile electrification, liquid cooling plates are particularly important for efficient heat dissipation of on-board electronic equipment and batteries. With the rapid development of electric vehicle technology, the capacity of on-board batteries has gradually increased, and the charging speed has continued to increase, which has put higher requirements on the heat dissipation system. As the main solution to these high-heat problems, although liquid cooling plates were able to meet some heat dissipation needs in the early days, with the advancement of technology, the design of existing liquid cooling plates has gradually become incapable of meeting the needs, especially when dealing with high-energy consumption equipment and complex heat distribution.

[0003] Existing liquid cooling plates mostly use simple flow channel designs, usually straight or circular flow channels with a single geometric shape. Although this design can achieve basic heat dissipation effects in some devices with low heat requirements, for modern high-performance devices, especially high-capacity battery systems in electric vehicles, traditional flow channel designs can no longer cope with complex heat distribution and conduction requirements. In particular, the high heat generated by the battery during high-power charging and discharging cannot be evenly dissipated by the traditional liquid cooling plate structure, resulting in overheating in local areas, affecting the performance and life of the battery.

[0004] Traditional liquid cold plates use not only coolant but also refrigerant for heat dissipation and heat transfer. As an efficient heat conduction medium in the liquid cold plate, the refrigerant can achieve rapid heat transfer within a large temperature difference range. However, a key characteristic of the refrigerant is that it is easy to vaporize and form bubbles in a high temperature environment. When the refrigerant flows in the flow channel of the liquid cold plate, if the local temperature is too high, the refrigerant will accumulate bubbles in the flow channel after being heated and vaporized. These bubbles will not only reduce the flow rate of the refrigerant, causing uneven local heat dissipation, but may also further form an air plug phenomenon, that is, the bubbles hinder the normal flow of the refrigerant, resulting in a significant decrease in the cooling efficiency of the liquid cold plate, and may even cause overheating in some high-heat areas, seriously affecting the heat dissipation needs of the battery system or electronic equipment. Especially when the refrigerant flow rate is low or the flow channel design is unreasonable, the air plug phenomenon is particularly prominent, the refrigerant circulation is blocked, and the cooling effect is significantly reduced.

[0005] In order to address these problems, the existing liquid cooling plate design needs to be optimized urgently. Summary of the invention

[0006] The purpose of this application is to overcome at least one of the shortcomings of the prior art, and to provide a dual-transport refrigerant direct cooling plate with a diffusion wall and a preparation method thereof, wherein the direct cooling plate achieves a refined treatment of the inner wall of the flow channel by etching complex capillary microgrooves on a high-aluminum alloy plate. The etched surface can not only increase the contact area between the refrigerant and the flow channel wall, but also improve the transmission efficiency of the refrigerant through capillary action, thereby effectively improving the overall heat exchange effect.

[0007] To achieve one of the purposes of the present application, in the first aspect, the present application discloses a dual-conveying refrigerant direct cooling plate with a diffusion wall, the direct cooling plate comprising an upper substrate and a lower substrate made of aluminum alloy, the upper substrate and / or the lower substrate having linear grooves, the upper substrate and the lower substrate cooperate to seal the linear grooves to form a plurality of linear flow channels; the inner wall surface of the linear flow channel has micro grooves arranged in the same direction along the linear flow channel, the depth of the micro grooves is controlled to be between 0.5-2mm, and a spiral capillary conveying groove is provided on the inner wall surface of the linear flow channel, the depth of the capillary conveying groove is controlled to be between 0.01-0.2mm, and the width is controlled to be between 0.1-0.2mm.

[0008] Furthermore, adjacent flow channels are connected via auxiliary channels.

[0009] The direct cooling plate utilizes a micro-groove structure to realize wall transport based on the capillary transport principle, thereby realizing a second wall transport in addition to the flow channel transport, thereby reducing the influence of air plugs.

[0010] In order to achieve one of the purposes of the present application, in a second aspect, the present application discloses a method for preparing a dual-transport refrigerant direct cooling plate with a diffusion wall, the preparation method comprising the following steps: Step S1: placing the upper substrate and / or the lower substrate made of aluminum alloy in a punching machine, punching out a linear groove with a depth of 20 mm to 50 mm, and reserving a flat connection surface of 5-10 mm.

[0011] Step S2: cleaning the upper substrate and the lower substrate to remove impurities.

[0012] Step S3: coating a photosensitive adhesive layer on the surface of the upper substrate and / or the lower substrate, and performing exposure to avoid a flat connection surface.

[0013] Step S4: Use sodium hydroxide solution to perform chemical etching to form linear micro grooves with an etching depth of 0.5 mm to 2 mm, ensuring that the direction is consistent.

[0014] Step S5: cleaning the substrate surface and removing the photosensitive resin layer.

[0015] Step S6: Align the upper substrate and the lower substrate and perform welding so that the linear grooves are relatively matched to form a linear path.

[0016] Step S7: Use an 800-mesh ball-end brush to perform rotational honing on the inner surface of the straight line after welding, with a honing depth of 0.02 mm to 0.2 mm.

[0017] Step S8: Perform a sealing test, inject high-pressure gas or liquid into the linear flow channel, check for leakage, ensure that the sealing of the flow channel meets the design requirements, and perform secondary welding repair if necessary.

[0018] The above preparation method is simple to operate, adopts standard stamping and chemical etching processes, has a clear process flow, and is conducive to industrial mass production; at the same time, the rotary honing treatment in the step ensures the smoothness of the inner wall of the flow channel, reduces processing errors, and improves product consistency and cooling effects; in addition, the sealing detection link ensures the reliability of product quality and further improves the stability of large-scale production.

[0019] 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

[0020] 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: Figure 1 It is a structural schematic diagram of an embodiment disclosed in this application.

[0021] Figure 2 It is a structural explosion diagram of an embodiment disclosed in the present application.

[0022] Figure 3 It is a schematic structural diagram of a lower substrate in an embodiment disclosed in the present application.

[0023] Figure 4 It is a schematic diagram of the partial structure of a lower substrate in an embodiment disclosed in the present application.

[0024] Figure 5 It is a structural schematic diagram of another embodiment disclosed in the present application. DETAILED DESCRIPTION

[0025] The present disclosure will be described below with reference to the accompanying drawings, which 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.

[0026] 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.

[0027] 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.

[0028] 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. Example

[0029] like Figures 1 to 4 As shown, the capillary conveying groove in the refrigerant direct cooling plate of this embodiment is designed to achieve wall conveying. This design is to solve the air plug problem caused by uneven flow in traditional cooling structures. Wall conveying refers to the process of refrigerant being transmitted along the inner wall surface of the flow channel. It evenly distributes the refrigerant on the inner wall surface through capillary action, ensuring that the refrigerant can effectively cover the entire cooling area.

[0030] In terms of specific structure, the direct cooling plate includes an upper base plate 1 and a lower base plate 2 made of aluminum alloy. A plurality of linear grooves 3 are provided on the lower base plate 1, and through the sealing cooperation between the upper base plate 1 and the lower base plate 2, these linear grooves 3 are sealed to form a plurality of linear flow channels 4. This design of the direct cooling plate can effectively utilize the flow of the refrigerant in the flow channel for heat transfer.

[0031] like Figure 2-4As shown in the figure, the design of the straight channel 4 not only relies on the flow of refrigerant inside the channel to conduct heat, but also has a unique micro-groove 5 structure on its inner wall. The micro-groove 5 is arranged in the same direction along the straight channel 4, and its depth is precisely controlled between 0.5 and 2 mm. The arrangement of this micro-groove 5 structure can increase the contact area between the refrigerant and the wall of the straight channel 4, further improving the heat conduction efficiency. At the same time, the existence of the micro-groove 5 provides a transportation basis for secondary transportation. In addition, Figure 4 As shown, a spiral capillary conveying groove 6 is also provided on the inner wall surface of the straight flow channel 4, which is a more unique design. The depth of the capillary conveying groove 6 is precisely controlled between 0.01 and 0.2 mm, and the width is controlled between 0.1 and 0.2 mm. These tiny and fine capillary conveying grooves 6 are based on the capillary conveying principle, and can transport the refrigerant on the wall surface of the straight flow channel 4 through the capillary effect, thereby realizing a second layer of wall surface transport in addition to the refrigerant transport inside the straight flow channel 4, that is, secondary transport. The advantage of this dual transport method is that the capillary conveying groove 6 can make the refrigerant evenly distributed and flow on the wall surface of the straight flow channel 4, and even when the refrigerant flow rate in the straight flow channel 4 is reduced or blocked, the wall surface transport can still continue, thereby greatly reducing the occurrence of air plugging.

[0032] In order to further optimize the flow efficiency of the refrigerant, such as Figure 5 As shown, adjacent straight channels 4 are connected by auxiliary channels 8. These auxiliary channels 8 enable the refrigerant to circulate between different straight channels 4, ensuring the uniform distribution of the refrigerant in the entire direct cooling plate, reducing the dead angle area in the channel, and further improving the uniformity and efficiency of heat dissipation.

[0033] It should be understood that wall transport plays a vital role in the direct cooling plate structure. First, in the traditional flow channel design, when the refrigerant flow rate is reduced or the refrigerant is obstructed in certain areas, the flow may be discontinuous, resulting in the refrigerant being unable to effectively cover all heat source areas. In this case, the temperature of the local area will rise rapidly, and bubbles are likely to be generated in the flow channel. The aggregation of bubbles will further cause the flow of the refrigerant in the flow channel to be obstructed, forming an air plug phenomenon. The generation of air plugs will greatly reduce the cooling effect and may cause local overheating. The capillary transport groove 6 utilizes the capillary effect to transport the refrigerant along the inner wall surface, and even when the refrigerant flow rate is low or the system pressure fluctuates, it can ensure that the refrigerant will not stagnate in the flow channel. The capillary effect depends on the adhesion between the liquid and the solid surface. The liquid will automatically rise or diffuse along the wall, so that the refrigerant can be evenly distributed in each part of the straight flow channel 4, avoiding the concentration of refrigerant in certain areas and causing insufficient cooling in other areas. Through wall transport, even when the main flow velocity of the refrigerant is not high, the refrigerant can still be effectively transported along the wall through the capillary transport groove 6, thereby maintaining the continuous flow of the refrigerant in the straight flow channel 4 and preventing the stagnation of the refrigerant and the generation of bubbles in certain areas. In terms of solving the problem of air blockage, wall transport reduces the generation and accumulation of bubbles by maintaining the uniform distribution of the refrigerant in the entire straight flow channel 4. Since bubbles are usually formed when the refrigerant is stagnant or the flow velocity is extremely low, the capillary transport groove 6 effectively prevents the occurrence of such stagnation by ensuring that the refrigerant continues to flow on the wall. At the same time, capillary transport allows the refrigerant to continue to flow on the wall even in the early stages of bubble generation, avoiding the accumulation or blockage of bubbles in the flow channel, thereby reducing the risk of air blockage.

[0034] It should be understood that, specifically, the transport capacity of the capillary transport groove 6 itself is limited. In order to improve the transport effect, the capillary transport grooves 6 are connected by adding micro grooves 5 with greater depth to form a complete capillary transport network. The micro grooves 5 play the role of the main channel in the straight flow channel 4, so that while the refrigerant is transported on the wall surface in the main channel, the capillary transport grooves 6 distribute and guide the refrigerant on the wall surface of the straight flow channel 4 through the capillary effect.

[0035] The advantage of this design is that the combination of the micro grooves 5 and the capillary conveying grooves 6 not only significantly increases the contact area between the refrigerant and the flow channel wall, but also greatly improves the actual conveying effect of the capillary conveying grooves 6 through the main flow channel effect of the micro grooves 5. Even when the refrigerant flow rate is low or the flow is partially blocked, the capillary conveying grooves 6 can still ensure uniform distribution of the refrigerant and avoid the formation of air plugs.

[0036] Through the above design, the direct cooling plate has significant improvements in the transport of refrigerant and the conduction of heat. The combination of micro grooves 5 and capillary conveying grooves 6 not only greatly increases the contact area between the refrigerant and the flow channel wall, but also effectively solves the air plug problem through the capillary conveying principle, significantly improving the heat dissipation effect of the direct cooling plate in high-heat application scenarios. This innovative design is particularly suitable for electric vehicle batteries and electronic equipment that require efficient heat dissipation, and can provide more uniform and reliable cooling performance.

[0037] To realize the above structure, the specific steps and process of production of this embodiment are as follows: The upper base plate 1 and the lower base plate 2 of the refrigerant direct cooling plate are made of high-performance 3003-H24 aluminum alloy material, which not only has good corrosion resistance, but also has excellent formability and thermal conductivity, and is suitable for harsh heat dissipation environments.

[0038] During the forming process of the upper substrate 1 and the lower substrate 2, a 200-ton hydraulic press is used to perform precision stamping on the aluminum alloy substrate, and a customized mold is used during the stamping process to form a linear groove 3. The depth of the linear groove 3 is strictly controlled between 20 mm and 50 mm.

[0039] In order to seal during subsequent welding, a 5mm to 10mm flat connection surface 7 is reserved on both sides of the linear groove 3. During the entire stamping process, the centering accuracy and stamping force of the mold are precisely controlled to ensure the uniformity of the forming of the linear groove 3 and avoid deformation of the upper substrate 1 and the lower substrate 2 caused by uneven stamping force, which not only helps to improve the welding accuracy, but also ensures the sealing and heat dissipation performance of the refrigerant flow channel.

[0040] After forming, the upper substrate 1 and the lower substrate 2 enter the cleaning and surface treatment process. The cleaning stage adopts a multi-step process to ensure that the surface of the substrate is clean and free of any residue. First, the surface of the upper substrate 1 and the lower substrate 2 is preliminarily cleaned with a mixed solution of acetone and isopropanol to remove oil and particulate matter. Then the upper substrate 1 and the lower substrate 2 are immersed in a sodium hydroxide solution for electro-degreasing. During this process, a direct current is applied to effectively remove the oxide film on the surface of the upper substrate 1 and the lower substrate 2. The electro-degreasing time is controlled at 3 to 5 minutes, and the current density is 1.5A / dm². After degreasing, the upper substrate 1 and the lower substrate 2 are rinsed with deionized water multiple times to ensure that the surface is completely clean and free of residual alkaline substances. Then, high-speed dry air is used to blow dry the surface of the upper substrate 1 and the lower substrate 2 at a flow rate of 10 meters per second to ensure that there is no residual liquid or impurities that affect the subsequent processing steps.

[0041] After the surface treatment is completed, the upper substrate 1 and / or the lower substrate 2 enter the photosensitive adhesive coating and etching process. Apply a layer of photosensitive adhesive with a thickness of 20 to 50 microns to ensure that the adhesive layer is uniform and free of bubbles. Then put the upper substrate 1 and / or the lower substrate 2 into a temperature-controlled drying oven, the temperature is controlled at 50°C to 60°C, and the drying time is 20 minutes. After drying, the upper substrate 1 and / or the lower substrate 2 are exposed by ultraviolet exposure equipment, and the time is controlled at 90 to 120 seconds to ensure that the exposed part of the photosensitive adhesive is completely cured. In this process, the flat connection surface that needs to be welded later is especially avoided. The development process uses a 3% sodium carbonate solution, and the development time is 30 seconds to 1 minute to ensure that the unexposed part of the photosensitive adhesive is completely removed, thereby revealing the etching area.

[0042] In the etching process, a 5%-8% sodium hydroxide solution is used to chemically etch the microgrooves on the substrate, and the etching temperature is controlled at 30°C to 40°C. By controlling the etching time and solution concentration, the depth of the microgrooves is ensured to be between 0.5mm and 2mm, and the width is controlled to be between 0.1mm and 0.2mm. Uniform and regular microgrooves 5 are formed on the surface of the etched flow channel. After etching, the substrate is neutralized with acetic acid solution to neutralize the alkaline substances remaining on the surface, and then thoroughly cleaned with an ultrasonic cleaning device for 3-5 minutes to ensure that there are no impurities or residual photosensitive adhesive on the surface of the upper substrate 1 and / or the lower substrate 2.

[0043] In order to ensure the strength and sealing of the refrigerant direct cooling plate, a process combining brazing and diffusion welding is adopted. During the brazing process, an aluminum-silicon brazing material with a thickness of 0.05mm to 0.1mm is evenly coated on the reserved flat connection surface 7 of the substrate, and then the upper substrate 1 and the lower substrate 2 are placed in a brazing furnace, the temperature is controlled at 570℃ to 610℃, and the heating time is 2 to 5 minutes to ensure that the brazing material is fully melted at high temperature and evenly fills the joint. After brazing, the substrate is naturally cooled to room temperature and enters the diffusion welding process. During the diffusion welding process, the substrate is placed in the diffusion welding equipment, the welding pressure is controlled at 5MPa to 10MPa, the welding temperature is 500℃ to 550℃, and the welding time is controlled at 30 minutes to 1 hour. During the diffusion welding process, through the action of high temperature and high pressure, the upper substrate 1 and the lower substrate 2 form a close bond at the molecular level, which not only improves the structural strength, but also ensures that the linear flow channel 4 is completely sealed except for the openings at both ends. In order to avoid thermal stress inside the material during welding, the substrate after welding is slowly cooled down to room temperature at a rate of 10°C per minute to ensure the structural stability of the material.

[0044] The welded refrigerant direct cooling plate enters the sealing test stage, and high-pressure helium or nitrogen is injected into the linear flow channel 4 of the direct cooling plate, and the pressure is controlled at 0.5MPa to 1.0MPa. The leak detection equipment is used to check whether there is gas leakage at the welding joint.

[0045] In addition, as an optional step, the inspection also includes the use of a laser interferometer measurement system to accurately measure the geometric dimensions and surface roughness of the inner part of the linear flow channel 4. In addition, the depth and width of the etched micro-grooves 5 are also carefully inspected to ensure that they are within the design range. If necessary, local secondary welding can be used for repair to ensure that the sealing of the refrigerant direct cooling plate fully meets the design standards.

[0046] The refrigerant direct cooling plate in this embodiment has extremely high refrigerant delivery capacity and reliable structural stability through the above complex and precise process flow, and is particularly suitable for the heat dissipation system of new energy vehicle batteries. Under high-speed charging or long-term high-load working conditions, the direct cooling plate can efficiently transfer heat, prevent the occurrence of air plugging, ensure the safe operation of the battery under various extreme conditions, and extend the service life of the battery. The structural design and manufacturing process of this refrigerant direct cooling plate provide an effective solution for future battery heat dissipation technology, significantly improving the safety and reliability of the equipment.

[0047] 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 dual-transport refrigerant direct cooling plate with a diffusion wall, characterized in that: The direct cooling plate comprises: an upper base plate and a lower base plate made of aluminum alloy, wherein the upper base plate and / or the lower base plate have linear grooves, and the upper base plate and the lower base plate cooperate to seal the linear grooves to form a plurality of linear flow channels; the inner wall surface of the linear flow channel has micro grooves arranged in the same direction along the linear flow channel, the depth of the micro grooves is controlled to be between 0.5-2mm, and a capillary conveying groove with a spiral direction is provided on the inner wall surface of the linear flow channel, the depth of the capillary conveying groove is controlled to be between 0.01-0.2mm, and the width is controlled to be between 0.1-0.2mm.

2. A dual-conveying refrigerant direct cooling plate with a diffusion wall as claimed in claim 1, characterized in that: Adjacent flow channels are connected through auxiliary channels.

3. A method for preparing a dual-conveying refrigerant direct cooling plate with a diffusion wall as claimed in claim 1, characterized in that: The preparation method comprises the following steps: Step S1: placing the upper substrate and / or the lower substrate made of aluminum alloy in a punching machine, punching out a linear groove, the depth of the groove is 20 mm to 50 mm, and reserving a flat connection surface of 5-10 mm; Step S2: cleaning the upper substrate and the lower substrate to remove impurities; Step S3: coating a photosensitive adhesive layer on the surface of the upper substrate and / or the lower substrate, and performing exposure to avoid a flat connection surface; Step S4: using sodium hydroxide solution to perform chemical etching to form linear micro grooves with an etching depth of 0.5 mm to 2 mm, ensuring that the direction is consistent; Step S5: cleaning the substrate surface and removing the photosensitive adhesive layer; Step S6: aligning the upper substrate and the lower substrate and welding them so that the straight grooves are relatively matched to form a straight path; Step S7: using an 800-mesh ball-end brush to perform rotary honing on the inner surface of the straight line after welding, with a honing depth of 0.02 mm to 0.2 mm; Step S8: Perform a sealing test, inject high-pressure gas or liquid into the linear flow channel, check for leakage, ensure that the sealing of the flow channel meets the design requirements, and perform secondary welding repair if necessary.

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