Liquid cooling plate and manufacturing method and heat dissipation method thereof

Abstract

The invention discloses a liquid cooling plate and a manufacturing method and a heat dissipation method thereof. The manufacturing method comprises the steps that a metal plate is cut according to the preset size of the liquid cooling plate, and an upper cover plate and a lower cover plate are obtained; after the upper surface of the lower cover plate is roughened, a graphite circuit is printed in a preset main runner area, a main runner is preset on the upper surface of the lower cover plate, the graphite circuit comprises a plurality of printing patterns, and the densities of the printing patterns in different areas in the main runner are different; covering the upper cover plate on the lower cover plate to enable the graphite circuit to be positioned between the upper cover plate and the lower cover plate, and performing hot rolling and rolling to form a composite plate; blowing holes are formed in the composite plate, a main flow channel is formed in the middle of the composite plate through a blowing process, and the liquid cooling plate is obtained. According to the liquid cooling plate and the manufacturing method and the heat dissipation method thereof, the printing pattern density of the graphite lines in different areas can be adjusted according to the heat dissipation requirements of the different areas in the main flow channel, and the heat dissipation efficiency and uniformity of the liquid cooling plate are improved.

Description

Technical Field

[0001] The present invention relates to the field of heat dissipation technology, and in particular to a liquid cooling plate and a manufacturing method thereof, and a heat dissipation method. Background Art

[0002] With the rapid development of new energy technologies, battery packs are core components in electric vehicles, energy storage systems, etc., and their heat dissipation performance directly affects the safety, reliability and service life of the system. Liquid cooling technology occupies an important position in the heat dissipation solution of new energy battery packs due to its efficient thermal conductivity and uniform heat dissipation effect.

[0003] At present, the mainstream battery pack liquid cooling plates on the market mostly adopt the brazed liquid cooling plate design with fins. Figure 5 This type of liquid cooling plate is usually welded by a flat cover plate and a flow channel plate that has been processed by stamping or other forming processes through a brazing process to form a closed refrigerant flow channel. At the same time, two water nozzle joints for the refrigerant inlet and outlet are welded on the cover plate. In the face of application scenarios with a large heat flux density of the heat source, in order to enhance the heat exchange efficiency, fins are often welded inside the flow channel to increase the contact area with the battery pack and promote effective heat transfer.

[0004] Although the brazed liquid cooling plate has certain structural advantages, its manufacturing process has many shortcomings: First, the brazing process requires a large welding furnace, which not only takes up a large space, but also consumes extremely high energy, resulting in increased production costs. Secondly, the thermal stress generated during the brazing process often causes deformation of the liquid cooling plate surface, affecting the surface flatness. Some products even require subsequent correction processes to meet the use requirements. Furthermore, the brazing process has extremely high requirements for manufacturing precision and welding technology. Any slight deviation may lead to the production of defective products, further increasing the difficulty and cost of quality control.

[0005] On the other hand, the cold plate produced by the inflation process is another common type of liquid cooling plate. Although its manufacturing process is relatively simple and the cost is low, its flow channel design is relatively simple and the heat exchange area is limited, which limits the improvement of its heat dissipation performance. Figure 6 More importantly, in the design of the traditional blown liquid cold plate, the two refrigerant flow channels are separated at the initial stage, forming two independent inlets, which makes it difficult to evenly distribute the refrigerant in the two flow channels, which in turn causes significant temperature differences in different areas of the battery pack, affecting the overall performance and life of the battery pack. In addition, the staggered paths of the traditional blown liquid cold plate have a large flow resistance and a small heat dissipation area, so the heat exchange effect is not ideal.

[0006] In summary, existing battery pack liquid cooling plates have limitations to varying degrees in terms of manufacturing process, cost control, heat dissipation efficiency and temperature uniformity. Summary of the invention

[0007] The purpose of the present invention is to solve at least the above-mentioned technical problems and to provide a liquid cooling plate and its manufacturing method and heat dissipation method, which can adjust the printing pattern density of graphite circuits in different areas according to the heat dissipation requirements of different areas in the main channel, thereby improving the heat dissipation efficiency and uniformity of the liquid cooling plate.

[0008] The purpose of the present invention is achieved by the following technical solutions:

[0009] In one aspect, the present invention provides a method for manufacturing a liquid cooling plate, comprising the following steps:

[0010] According to the preset size of the liquid cooling plate, the metal plate is cut to obtain an upper cover plate and a lower cover plate;

[0011] After roughening the upper surface of the lower cover plate, a graphite circuit is printed in a preset main channel area, wherein the main channel is preset on the upper surface of the lower cover plate, the graphite circuit includes a plurality of printed patterns, and the density of the printed patterns in different areas of the main channel is different;

[0012] Laminating the upper cover plate on the lower cover plate so that the graphite circuit is located between the upper cover plate and the lower cover plate, and hot rolling and rolling to form a composite plate;

[0013] A blowing hole is opened on the composite plate, and a main flow channel is formed in the middle of the composite plate through a blowing process to obtain a liquid cooling plate.

[0014] The beneficial effects of the above scheme are as follows: (1) The present invention cuts the metal plate according to the preset size, which can meet the heat dissipation requirements of different equipment and systems, enhance the applicability of the product, and realize customized production. (2) The roughening treatment of the present invention increases the roughness of the metal plate surface, which is conducive to the firm adhesion of the graphite circuit. (3) The present invention forms a graphite circuit in the main channel area through a printing process, avoiding complex mechanical processing and reducing the difficulty of production; at the same time, the flow channel formed by the graphite circuit enables the liquid cooling plate to quickly conduct and dissipate heat, which is suitable for scenes requiring efficient heat dissipation such as high-power battery packs and electronic equipment. In addition, by differentiating the density of the printed pattern, not only can the uniform flow and heat exchange of the refrigerant in the flow channel be achieved to avoid local overheating, but also the flow and heat exchange efficiency of the refrigerant can be optimized according to the heat dissipation requirements, for example: increasing the density of the printed pattern in the area where heat is concentrated to absorb and disperse heat more effectively; reducing the density in the area where heat is low or flow demand is high, reducing flow resistance, and maintaining smooth flow of the refrigerant. (4) The hot rolling process of the present invention can eliminate defects and stresses inside the material and improve the reliability and service life of the product. (5) Compared with the traditional mechanical processing method, the inflation process of the present invention not only greatly simplifies the production process and reduces the production cost, but also can form a main channel with a smooth surface and precise size, which is conducive to the smooth flow of refrigerant and the efficient transfer of heat.

[0015] Furthermore, before roughening the upper surface of the lower cover plate, the following steps are also included:

[0016] The upper cover plate and the lower cover plate are annealed and then cooled to room temperature;

[0017] After the hot rolling and rolling to form the composite plate, the following steps are also included:

[0018] The composite plate is annealed and then leveled by a leveler;

[0019] In the inflation process, the pipeline is expanded by filling with high-pressure fluid to form a main flow channel in the interlayer of the composite plate.

[0020] The beneficial effects of the above scheme are: the present invention improves the mechanical properties and ductility of the metal plate through annealing treatment, which is convenient for subsequent processing. Furthermore, the combination of annealing treatment and leveling process of the present invention reduces the internal stress and deformation of the composite plate, and improves the flatness and quality of the liquid cooling plate. In addition, through the high-pressure fluid inflation process, the main flow channel can be accurately formed in the composite plate interlayer to ensure the consistency of the flow channel shape and size.

[0021] Furthermore, the annealing temperature is 350°C to 450°C, and the annealing time is 1h to 3h;

[0022] The temperature of the hot rolling is 400°C to 500°C;

[0023] The pressure of the high-pressure fluid is 1MPa to 3MPa, and the inflation time is 10s to 30s.

[0024] The beneficial effects of the above scheme are as follows: the present invention ensures the stability and controllability of the process by setting the annealing temperature, hot rolling temperature and pressure, and the pressure and time of the inflation process, thereby improving the manufacturing accuracy and performance of the liquid cooling plate. In addition, the optimized process parameters reduce defects in the processing process and improve the yield rate and performance consistency of the liquid cooling plate.

[0025] Furthermore, the printed pattern includes dots and / or lines, and a plurality of the printed patterns are arranged in a staggered manner in the main channel, and the flow path in the main channel is wavy or spiral.

[0026] The beneficial effects of the above scheme are as follows: the staggered arrangement of the dot-shaped and / or line-shaped printed patterns and the wavy or spiral flow path of the present invention not only increase the disturbance of the refrigerant in the main channel, but also increase the heat exchange area, improve the heat exchange efficiency, and enhance the strength and stability of the liquid cooling plate. In addition, by optimizing the distribution of the printed patterns, the refrigerant can dissipate heat evenly when flowing in the main channel to avoid local overheating.

[0027] Furthermore, the density of the printed pattern in the water inlet area of ​​the main channel is 15 to 20 per cm 2 The density of the printed pattern in the outlet area of ​​the main channel is 5 to 10 per cm 2 ;

[0028] The flow velocity of the refrigerant in the main flow channel is 0.5 m / s to 2 m / s.

[0029] The beneficial effect of the above scheme is that the present invention adjusts the flow rate and flow distribution of the refrigerant in the main channel by setting the density difference of the printed pattern in the water inlet and water outlet areas, thereby improving the heat dissipation efficiency. Furthermore, the high-density printed pattern in the water inlet area can ensure the rapid distribution of the refrigerant, while the low-density printed pattern in the water outlet area can reduce the flow resistance, optimize the flow rate of the refrigerant, and improve the heat dissipation effect. In addition, the setting of the refrigerant flow rate (0.5m / s~2m / s) can reduce the flow resistance and energy consumption while ensuring the heat dissipation effect.

[0030] Furthermore, the main flow channel includes one or more sections of refrigerant flow channels, the angle between two adjacent sections of the refrigerant flow channels is 0-180°, and the density of printed patterns in different areas of each section of the refrigerant flow channel is different.

[0031] The beneficial effects of the above scheme are as follows: the present invention increases the flow path of the refrigerant, prolongs the heat exchange time, and improves the heat dissipation effect by sequentially connecting multiple refrigerant flow channels. By adjusting the angle between adjacent refrigerant flow channels, the flow direction and path of the refrigerant can be changed to adapt to battery packs of different shapes and sizes, thereby improving the adaptability of the liquid cooling plate. At the same time, by adjusting the angle, the internal space of the liquid cooling plate can be more efficiently utilized to improve the heat dissipation efficiency. In addition, the density of printed patterns in different areas of each refrigerant flow channel can be flexibly arranged according to actual heat dissipation needs, thereby improving the performance of the liquid cooling plate and optimizing the heat dissipation effect.

[0032] Furthermore, each section of the refrigerant flow channel includes a first end, a middle portion, and a second end which are sequentially arranged, the first end being a water inlet of the refrigerant flow channel, and the second end being a water outlet of the refrigerant flow channel;

[0033] The multiple sections of the refrigerant flow channel are connected in sequence, and in two adjacent sections of the refrigerant flow channel, the second end of one section of the refrigerant flow channel is connected to the first end of the other section of the refrigerant flow channel.

[0034] The beneficial effect of the above scheme is that the present invention can ensure the uniform distribution and flow of the refrigerant in the liquid cooling plate and improve the heat dissipation efficiency by providing a plurality of refrigerant flow channels and connecting them in sequence.

[0035] Furthermore, the printing thickness of the graphite circuit is 0.1 mm to 0.3 mm;

[0036] At the first end of the refrigerant flow channel: the spacing of the printed pattern of the graphite circuit is 1 mm to 2 mm;

[0037] In the middle of the refrigerant flow channel: the spacing of the printed pattern of the graphite circuit is 3mm to 5mm;

[0038] At the second end of the coolant flow channel: the spacing of the printed pattern of the graphite circuit is 6 mm to 10 mm.

[0039] The beneficial effect of the above scheme is that the present invention optimizes the uniformity of the refrigerant flow and the heat exchange efficiency by setting different printed pattern spacings in different areas. Furthermore, a smaller spacing is set in the water inlet area of ​​the refrigerant flow channel to increase the disturbance of the refrigerant; a larger spacing is set in the water outlet area to reduce the flow resistance and improve the overall heat dissipation performance.

[0040] In a second aspect, the present invention provides a liquid cooling plate obtained by using the above-mentioned method for manufacturing the liquid cooling plate.

[0041] The beneficial effect of the above scheme is that the liquid cooling plate obtained by the above manufacturing method of the present invention has the advantages of simple structure, high heat dissipation efficiency, stable performance, etc., and is suitable for various occasions requiring heat dissipation.

[0042] In a third aspect, the present invention provides a heat dissipation method, which is implemented by using the above-mentioned liquid cooling plate, wherein a plurality of heat exchange columns are provided in the main flow channel;

[0043] The heat dissipation method comprises the following steps:

[0044] The refrigerant is injected into the main channel of the liquid cooling plate through the water inlet nozzle, and flows through multiple staggered heat exchange columns to form a multi-channel fluid;

[0045] The refrigerant exchanges heat when flowing in the flow channel;

[0046] The refrigerant flows out of the liquid cooling plate through the water outlet to dissipate heat for the battery pack.

[0047] The beneficial effect of the above scheme is that the heat dissipation method implemented by the present invention using the above liquid cooling plate can efficiently remove heat from heat sources such as battery packs, ensuring the normal operation of the equipment and extending its service life. At the same time, the method has the advantages of simple operation, low cost, etc., and has high practical value.

[0048] Compared with the prior art, the beneficial effects of the present invention include at least:

[0049] The beneficial effects of the above scheme are as follows: the present invention simplifies the production process of the liquid cooling plate and improves production efficiency by cutting the metal plate, printing the graphite circuit, hot rolling and inflation process. By making the printed pattern density of the graphite circuit in different areas different, it can be optimized according to the heat dissipation requirements of different areas in the main channel, thereby improving the heat dissipation efficiency and uniformity of the liquid cooling plate. The composite plate is formed by hot rolling, which enhances the structural strength and stability of the liquid cooling plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The present invention is a flow chart of a method for manufacturing a liquid cooling plate according to an embodiment of the present invention.

[0051] Figure 2 It is a structural schematic diagram of a liquid cooling plate according to an embodiment of the present invention.

[0052] Figure 3 The present invention is a schematic flow chart of a method for dissipating heat of a liquid cooling plate according to an embodiment of the present invention.

[0053] Figure 4 Schematic diagram of the structure of the main channel of the embodiment of the present invention.

[0054] Figure 5 It is a structural schematic diagram of a brazed liquid cooling plate in the prior art.

[0055] Figure 6 It is a structural schematic diagram of a traditional inflatable liquid cooling plate in the prior art.

[0056] In the figure: 1, lower cover plate; 2, upper cover plate; 3, graphite circuit; 31, printed pattern; 4, main channel; 40, refrigerant channel; 401, first end; 402, middle; 403, second end; 411, first channel; 412, second channel; 42, flow path; 5, inflation hole; 61, water inlet; 62, water outlet. DETAILED DESCRIPTION

[0057] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted.

[0058] The words expressing positions and directions described in the present invention are all explained with reference to the accompanying drawings as examples, but they can be changed as needed, and all such changes are included in the protection scope of the present invention.

[0059] refer to Figure 1The method for manufacturing a liquid cooling plate of the present invention includes steps S11 to S14.

[0060] Step S11: cutting the metal plate according to the preset size of the liquid cooling plate to obtain the upper cover plate 2 and the lower cover plate 1.

[0061] In application, after obtaining the upper cover plate 2 and the lower cover plate 1, the upper cover plate 2 and the lower cover plate 1 are annealed and then cooled to room temperature to improve the mechanical properties and ductility of the metal plate for subsequent processing. Specifically, the annealing temperature is 350°C to 450°C and the annealing time is 1h to 3h.

[0062] In actual application, cutting the metal plate according to the preset size can meet the heat dissipation requirements of different devices and systems, enhance the applicability of the product, and realize customized production or mass production. The preset size includes the length, width and thickness of the upper cover plate 2 and the lower cover plate 1; the metal plate includes an aluminum alloy plate, a copper alloy plate and / or a stainless steel plate. Preferably, the metal plate is an aluminum alloy plate.

[0063] Step S12: After roughening the upper surface of the lower cover plate 1 , a graphite circuit 3 is printed in a preset main flow channel 4 area.

[0064] When in use, the main channel 4 is preset on the upper surface of the lower cover plate 1. The roughness of the upper surface after roughening is increased, which is conducive to the firm adhesion of the graphite circuit 3. The graphite circuit 3 is formed in the main channel 4 area through the printing process, which not only avoids complex mechanical processing, but also enables the liquid cooling plate to quickly conduct and dissipate heat.

[0065] In actual application, the graphite circuit 3 needs to be sent to a dryer for drying. The graphite circuit 3 includes a plurality of printed patterns 31, the printed patterns 31 include dots and / or lines, the printing thickness is 0.1mm to 0.3mm, and the plurality of printed patterns 31 are staggered in the main channel 4, so that the flow path 42 in the main channel 4 is wavy or spiral, which not only increases the disturbance of the refrigerant in the main channel 4, so that the refrigerant can evenly dissipate heat when flowing in the main channel 4, avoiding local overheating, but also increases the heat exchange area and improves the heat exchange efficiency.

[0066] In addition, the density of the printed pattern 31 in different areas of the main channel 4 of the present invention is different. By differentiating the density of the printed pattern 31, not only can the uniform flow and heat exchange of the refrigerant in the channel be achieved to avoid local overheating, but also the flow and heat exchange efficiency of the refrigerant can be optimized according to the heat dissipation requirements, for example: the density of the printed pattern 31 is increased in the area where the heat is concentrated to absorb and disperse the heat more effectively; the density is reduced in the area where the heat is low or the flow demand is high to reduce the flow resistance and maintain the smooth flow of the refrigerant.

[0067] In some embodiments, the density of the printed pattern 31 in the water inlet area of ​​the main channel 4 is 15 to 20 per cm 2 The density of the printed pattern 31 in the outlet area of ​​the main channel 4 is 5 to 10 per cm 2 . In some other embodiments, the spacing of the printed patterns 31 in the water inlet area of ​​the main channel 4 is 1mm to 2mm; the spacing of the printed patterns 31 in the middle 402 area of ​​the main channel 4 is 3mm to 5mm; the spacing of the printed patterns 31 in the water outlet area of ​​the main channel 4 is 6mm to 10mm. It can be seen that a smaller spacing is set in the water inlet area to increase the disturbance of the refrigerant; a larger spacing is set in the water outlet area to reduce the flow resistance and improve the overall heat dissipation performance. In some preferred embodiments, in order to further optimize the flow and heat exchange efficiency of the refrigerant according to the heat dissipation requirements, the sizes of the printed patterns 31 in different areas of the main channel 4 of the present invention are different to adjust the width of the flow path 42. For example: the diameters of the dot-shaped printed patterns 31 are different, and the lengths of the linear printed patterns 31 are different.

[0068] Step S13: Lay the upper cover plate 2 on the lower cover plate 1 so that the graphite circuit 3 is located between the upper cover plate 2 and the lower cover plate 1, and perform hot rolling and rolling to form a composite plate.

[0069] When used, the upper cover plate 2 and the lower cover plate 1 are placed in a heating furnace for heating, and the heated double-layer metal plates are hot rolled and rolled. After the hot rolling and rolling forms a composite plate, the composite plate is annealed and leveled by a leveling machine after annealing, which can reduce the internal stress and deformation of the composite plate and improve the flatness and quality of the liquid-cooled plate. Specifically, the annealing temperature is 350℃~450℃, and the annealing time is 1h~3h; the hot rolling and rolling temperature is 400℃~500℃, and the rolling pressure is 1200-1500 tons.

[0070] During the annealing stage, the temperature is controlled within the range of 350°C to 450°C to ensure that the material can achieve the required microstructure and physical properties. At the same time, the annealing time is controlled to 1 hour to 3 hours to fully ensure that the stress inside the material is released and that unnecessary grain growth will not occur due to too long annealing. During the hot rolling stage, the temperature is controlled to 400°C to 500°C to ensure that the material has good thermoplasticity and deformation ability, thereby facilitating an efficient rolling process. During the forming process of the liquid-cooled plate, the pressure of the high-pressure fluid is controlled between 1MPa and 3MPa to ensure that the fluid can fully penetrate into the pores of the material and form the desired shape and size during the blowing process. The blowing time is set between 10 seconds and 30 seconds to balance the forming efficiency and product quality, and to avoid excessive deformation or rupture of the material due to too long blowing time.

[0071] Step S14: a blowing hole 5 is opened on the composite plate, and a main flow channel 4 is formed in the middle of the composite plate through a blowing process to obtain a liquid cooling plate.

[0072] When used, in the inflation process, the inflation hole 5 is connected to the graphite line 3, the inflation hole 5 is aligned with the air inlet, and the inflation mold is preheated to a suitable temperature in advance, and the pipeline is expanded by filling high-pressure fluid to form a main channel 4 in the interlayer of the composite plate. In actual application, in order to improve the manufacturing accuracy and performance of the liquid cooling plate, the pressure of the high-pressure fluid is set to 1MPa to 3MPa, and the inflation time is 10s to 30s.

[0073] refer to Figure 2 The liquid cooling plate obtained by the above manufacturing method of the present invention comprises: a water inlet 61, a water outlet 62, an upper cover plate 2, a lower cover plate 1, a graphite circuit 3 and a main channel 4. The main channel 4 is arranged between the upper cover plate 2 and the lower cover plate 1, and the graphite circuit 3 is printed in the main channel 4.

[0074] When used, the dot-shaped and / or line-shaped printed patterns 31 of the graphite circuit 3 form heat exchange columns in the main channel 4 , and the gaps between the staggered printed patterns form flow paths 42 in the main channel 4 .

[0075] In actual application, different density printed patterns 31 are arranged in different areas of the main channel 4, so that the flow rate of the refrigerant in the main channel 4 is 0.5m / s to 2m / s. The refrigerant is water or other suitable liquid cooling medium, such as ethylene glycol solution or nanofluid. In addition, the water inlet 61 is connected to the water inlet of the main channel 4 and is used for the refrigerant to flow in; the water outlet 62 is connected to the water outlet of the main channel 4 corresponding to the water inlet and is used for the refrigerant to flow out.

[0076] In addition, the main flow channel 4 includes a first flow channel 411 and a second flow channel 412, and a partition is provided between the first flow channel 411 and the second flow channel 412, so as to form two parallel parts of the refrigerant entering the water inlet. When used, the first flow channel 411 and the second flow channel 412 are parallel in the same direction and meet at the head and tail, which can not only increase the heat dissipation area, but also reasonably reduce the volume of the liquid cooling plate, and is suitable for dual-module products that require simultaneous temperature control and require uniform temperature.

[0077] In order to adapt to different heat dissipation requirements and installation spaces, the main channel 4 of the present invention is a straight main channel 4, a curved main channel 4 or a broken line main channel 4. Among them, the straight main channel 4 is composed of a straight line segment. The curved main channel 4 is composed of a straight line segment and an arc segment, and the shape of the curve includes a U-shape, an S-shape or a serpentine shape; the broken line main channel 4 is composed of a straight line segment and a corner segment, and the angle of the corner includes an acute angle, a right angle, an obtuse angle and / or a flat angle.

[0078] When used, the arc segment or the corner segment divides the main channel 4 into two or more segments of the refrigerant flow channel 40, that is, one straight segment corresponds to one refrigerant flow channel 40. When the main channel 4 is a straight main channel 4, the main channel 4 is regarded as one refrigerant flow channel 40. It can be seen that the main channel 4 includes one or more segments of the refrigerant flow channel 40.

[0079] In actual application, the angle between two adjacent sections of the refrigerant flow channel 40 is 0-180°, and the density of the printed pattern 31 in different areas of each section of the refrigerant flow channel 40 is different.

[0080] In addition, in order to further optimize the flow of the refrigerant and the heat exchange efficiency according to the heat dissipation requirements, the sizes of the printed patterns 31 in different areas of the main channel 4 of the present invention are different to adjust the width of the flow path 42. For example, the diameters of the dot-shaped printed patterns 31 are different, and the lengths of the line-shaped printed patterns 31 are different.

[0081] Each section of the refrigerant flow channel 40 of the present invention includes a first end 401, a middle part 402 and a second end 403 which are arranged in sequence, and the first end 401 of the refrigerant flow channel 40 corresponds to one end of the straight segment, the middle part 402 of the refrigerant flow channel 40 corresponds to the middle part of the straight segment, and the second end 403 of the refrigerant flow channel corresponds to the other end of the straight segment.

[0082] In application, multiple sections of the refrigerant flow channel 40 are connected in sequence, and in two adjacent sections of the refrigerant flow channel 40, the second end 403 of one section of the refrigerant flow channel 40 is connected to the first end 401 of the other section of the refrigerant flow channel 40. In actual application, the first end 401 is the water inlet of the refrigerant flow channel 40, and the second end 403 is the water outlet of the refrigerant flow channel 40.

[0083] In order to optimize the flow of the refrigerant and the heat exchange efficiency according to the heat dissipation requirements, the density of the printed pattern 31 in different areas of the refrigerant flow channel 40 in different sections is different.

[0084] When applied, the water inlet 61 is used as the starting point, and the refrigerant flow channels 40 arranged in sequence are numbered in sequence, and the density of the printed pattern 31 of the refrigerant flow channel 40 of the N+1th section is greater than the density of the printed pattern 31 of the refrigerant flow channel 40 of the Nth section, wherein N is greater than or equal to 1. In actual application, the density of the printed pattern 31 of the second end 403 and the middle 402 area of ​​the refrigerant flow channel 40 of the N+1th section is greater than the density of the printed pattern 31 of the second end 403 and the middle 402 area of ​​the refrigerant flow channel 40 of the Nth section, so as to offset the local temperature rise of the battery pack caused by the rise in the refrigerant temperature, reduce the temperature difference of the battery pack, and make the temperature of the battery pack uniform.

[0085] In actual application: the spacing of the printed pattern 31 at the first end 401 of the refrigerant flow channel 40 is 1mm to 2mm; the spacing of the printed pattern 31 in the middle 402 of the refrigerant flow channel 40 is 3mm to 5mm; the spacing of the printed pattern 31 at the second end 403 of the refrigerant flow channel 40 is 6mm to 10mm.

[0086] In order to further optimize the flow of the refrigerant and the heat exchange efficiency according to the heat dissipation requirements, the sizes of the printed patterns 31 in different areas of the refrigerant flow channels 40 in different sections of the present invention are different to adjust the width of the flow path 42 .

[0087] When applied, the refrigerant flow channels 40 arranged in sequence are numbered in sequence with the water inlet 61 as the starting point, and the size of the printed pattern 31 of the refrigerant flow channel 40 of the N+1th section is larger than the size of the printed pattern 31 of the refrigerant flow channel 40 of the Nth section, wherein N is greater than or equal to 1. In actual application, the size of the printed pattern 31 of the second end 403 and the middle 402 area of ​​the refrigerant flow channel 40 of the N+1th section is larger than the size of the printed pattern 31 of the second end 403 and the middle 402 area of ​​the refrigerant flow channel 40 of the Nth section, so as to offset the local temperature rise of the battery pack caused by the rise in the refrigerant temperature, reduce the temperature difference of the battery pack, and make the temperature of the battery pack uniform.

[0088] refer to Figure 3 The heat dissipation method implemented by the liquid cooling plate of the present invention includes the following steps: step S21 to step S23.

[0089] Step S21: inject the refrigerant into the main channel 4 of the liquid cooling plate through the water inlet nozzle 61, and flow through a plurality of staggered heat exchange columns to form a multi-channel fluid.

[0090] When applying, refer to Figure 4 The water flow connected to the water inlet is columnar, relatively concentrated, and the water flow pressure is relatively large. The high-density heat exchange columns at the water inlet can not only increase the flow resistance, but also generate strong disturbances when the refrigerant just enters the main channel 4, so that the water flow passing through the heat exchange column is divided into two, forming a stream, realizing the rapid dispersion of the refrigerant, and making the refrigerant flow evenly into the main channel 4, avoiding local temperature differences caused by uneven flow; and at the water outlet, in order to reduce the flow resistance and ensure the smooth outflow of the refrigerant, a lower density of heat exchange columns is set. For example: the density of heat exchange columns in the water inlet area is 15 to 20 / cm 2 The heat exchange column density in the outlet area is 5 to 10 / cm 2 .

[0091] Step S22: The refrigerant performs heat exchange while flowing in the flow channel.

[0092] In application, when the battery pack that needs uniform heat dissipation includes 4 rows of battery packs arranged in parallel, and each row of battery packs is provided with a plurality of battery cells, the main flow channel 4 of the present invention is a zigzag main flow channel 4, and includes a first straight line segment, a second straight line segment and a corner segment with a right angle, as shown in Figure 4. Specifically, the first end 401 of the refrigerant flow channel 40 corresponding to the first straight line segment is connected to the water inlet nozzle 61, the second end 403 of the refrigerant flow channel 40 corresponding to the second straight line segment is connected to the water outlet nozzle 62, and a refrigerant flow channel 40 is connected to each side of the corner segment with a right angle, so as to connect the refrigerant flow channel 40 corresponding to the first straight line segment and the refrigerant flow channel 40 corresponding to the second straight line segment. In addition, the two refrigerant flow channels 40 run in the same direction and in reverse.

[0093] In actual application, in order to make the temperature of each battery cell the same and uniform, and to prevent a battery cell from being too high or too low in temperature, which may cause the battery group or battery pack to fail, when the water flows from the water inlet 61 into the first straight section, the heat exchange column at the first end 401 of the refrigerant flow channel 40 corresponding to the first straight section evenly distributes the water flow, and the middle part 402 and the second end 403 of the refrigerant flow channel 40 are provided with relatively sparse heat exchange columns to reduce flow resistance. After the water flows through the corner section, the first end 401 of the refrigerant flow channel 40 corresponding to the second straight section continues to evenly distribute the water flow.

[0094] In addition, during the first straight section, the temperature difference between the liquid cooling plate and the refrigerant is relatively large, and the refrigerant absorbs heat and its temperature rises during the flow process. Therefore, during the second straight section, the temperature difference between the liquid cooling plate and the refrigerant is relatively small. Since the heat exchange area of ​​the flow channel is larger and the cross-sectional area is smaller where the density of the heat exchange column is high, the refrigerant flow rate is faster and the heat exchange coefficient is higher, when the refrigerant flows through the first end 401 and the middle part 402 of the refrigerant flow channel 40 corresponding to the second straight section, the rising temperature of the refrigerant will compensate for the temperature difference between the liquid cooling plate and the refrigerant, so that the overall temperature difference of the liquid cooling plate is smaller, thereby ensuring that the overall temperature difference of the battery pack is smaller.

[0095] Step S23: The refrigerant flows out of the liquid cooling plate through the water outlet 62 to dissipate heat for the battery pack.

[0096] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the invention. A person skilled in the art may change, modify, substitute and modify the above embodiments within the scope of the invention without departing from the principles and purpose of the present invention. All such changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a liquid cooling plate, characterized in that: The following steps are involved: According to the preset size of the liquid cooling plate, the metal plate is cut to obtain an upper cover plate (2) and a lower cover plate (1); After roughening the upper surface of the lower cover plate (1), a graphite circuit (3) is printed in a preset main channel (4) area, wherein the main channel (4) is preset on the upper surface of the lower cover plate (1), the graphite circuit (3) includes a plurality of printed patterns (31), and the density of the printed patterns (31) in different areas of the main channel (4) is different; Laminating the upper cover plate (2) on the lower cover plate (1) so that the graphite circuit (3) is located between the upper cover plate (2) and the lower cover plate (1), and hot rolling and pressing to form a composite plate; A blowing hole (5) is opened on the composite plate, and a main flow channel (4) is formed in the middle of the composite plate through a blowing process to obtain a liquid cooling plate.

2. The method for manufacturing a liquid cooling plate according to claim 1, characterized in that: Before roughening the upper surface of the lower cover plate (1), the following steps are also included: Performing annealing treatment on the upper cover plate (2) and the lower cover plate (1), and then cooling them to room temperature; After the hot rolling and rolling to form the composite plate, the following steps are also included: The composite plate is annealed and then leveled by a leveler; In the inflation process, the pipeline is expanded by injecting high-pressure fluid, thereby forming a main flow channel (4) in the interlayer of the composite plate.

3. The method for manufacturing a liquid cooling plate according to claim 2, characterized in that: The annealing temperature is 350°C to 450°C, and the annealing time is 1h to 3h; The temperature of the hot rolling is 400°C to 500°C; The pressure of the high-pressure fluid is 1MPa to 3MPa, and the inflation time is 10s to 30s.

4. The method for manufacturing a liquid cooling plate according to claim 1, characterized in that: The printed pattern (31) comprises dots and / or lines, a plurality of the printed patterns (31) are arranged in a staggered manner in the main channel (4), and the flow path (42) in the main channel (4) is wavy or spiral.

5. The method for manufacturing a liquid cooling plate according to claim 1, characterized in that: The density of the printed pattern (31) in the water inlet region of the main channel (4) is 15 to 20 per cm 2 The density of the printed pattern (31) in the outlet area of ​​the main channel (4) is 5 to 10 per cm 2 ; The flow velocity of the refrigerant in the main channel (4) is 0.5 m / s to 2 m / s.

6. The method for manufacturing a liquid cooling plate according to claim 1, characterized in that: The main flow channel (4) includes one or more sections of refrigerant flow channels (40), the angle between two adjacent sections of the refrigerant flow channels (40) is 0 to 180 degrees, and the density of the printed pattern (31) in different areas of each section of the refrigerant flow channel (40) is different.

7. The method for manufacturing a liquid cooling plate according to claim 6, characterized in that: Each section of the refrigerant flow channel (40) comprises a first end (401), a middle portion (402) and a second end (403) which are arranged in sequence, wherein the first end (401) is a water inlet of the refrigerant flow channel (40), and the second end (403) is a water outlet of the refrigerant flow channel (40); The multiple sections of the refrigerant flow channel (40) are connected in sequence, and in two adjacent sections of the refrigerant flow channel (40), the second end (403) of one section of the refrigerant flow channel (40) is connected to the first end (401) of the other section of the refrigerant flow channel (40).

8. The method for manufacturing a liquid cooling plate according to claim 6, characterized in that: The printed thickness of the graphite circuit (3) is 0.1 mm to 0.3 mm; At the first end (401) of the cooling medium flow channel (40): the spacing of the printed pattern (31) of the graphite circuit (3) is 1 mm to 2 mm; In the middle part (402) of the cooling medium flow channel (40): the spacing of the printed pattern (31) of the graphite circuit (3) is 3 mm to 5 mm; At the second end (403) of the cooling medium flow channel (40): the spacing of the printed pattern (31) of the graphite circuit (3) is 6 mm to 10 mm.

9. A liquid cooling plate, characterized in that: The liquid cooling plate is obtained by using the manufacturing method of any one of claims 1 to 8.

10. A method for heat dissipation of a liquid cooling plate, characterized in that: The liquid cooling plate according to claim 9 is used, wherein a plurality of heat exchange columns are provided in the main channel (4); The heat dissipation method comprises the following steps: The refrigerant is injected into the main channel (4) of the liquid cooling plate through the water inlet nozzle (61), and flows through a plurality of staggered heat exchange columns to form a multi-channel fluid; The refrigerant exchanges heat when flowing in the flow channel; The refrigerant flows out of the liquid cooling plate through the water outlet nozzle (62), thereby achieving heat dissipation for the battery pack.

Images