Heatsink assembly

Abstract

The disclosed heat sink assembly has a plurality of flow paths integrally formed along the internal longitudinal direction by extrusion molding, the spaces between the flow paths form solid portions, first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow paths include a heat sink spaced apart from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, with the first surface having both an inlet port through which the refrigerant flows in and an outlet port through which the refrigerant flows out, and the second surface forming a return flow path for the refrigerant.

Description

Technical Field

[0001] The present invention relates to a heat sink assembly that is mounted on the bottom surface of a battery pack equipped with a plurality of secondary batteries and promotes heat dissipation of the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0071942 filed on June 2, 2023, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries can be recharged and have been extensively researched and developed in recent years due to their potential for miniaturization and increased capacity. With the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in line with the contemporary requirements of environmental protection, the demand for secondary batteries as an energy source has been increasing even more rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. The electrode assembly mounted inside the battery case in a secondary battery is a power generation element capable of charge and discharge, which consists of a laminated structure of electrodes and a separator.

[0005] Since secondary batteries are required to be used continuously for a long period, it is necessary to effectively control the heat generated during the charge and discharge process. If the cooling of the secondary battery is not smoothly performed, the temperature rise causes an increase in current, and the increase in current causes a positive feedback chain reaction that again causes a temperature rise, ultimately leading to a catastrophic state of thermal runaway.

[0006] To effectively dissipate the heat generated by secondary batteries, heat sinks (also called cooling plates) with flowing coolants are widely used. Heat sinks are attached to the bottom of a group of secondary batteries, such as a battery pack containing many secondary batteries, and perform a cooling function by absorbing the heat generated inside the pack with a coolant and releasing it to the outside.

[0007] Heat sinks can be divided into brazed heat sinks and extruded heat sinks depending on their structure or manufacturing method. Brazed heat sinks have a structure in which two plate materials are brazed together to form a flow channel. While this offers a high degree of freedom in flow channel design, it has the disadvantage of having poor structural rigidity due to the deterioration of the material's physical properties. In contrast, extruded heat sinks, which are manufactured as a continuous body by extrusion molding, have an advantage in structural rigidity, but only straight flow channels can be realized, resulting in many ports, which in turn occupies space for connecting pipes. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a heat sink assembly that, despite being an extruded heat sink, does not require separate pipes for flow path formation, occupies less space, and improves differential pressure by reducing the number of parts with a simplified flow path configuration, thereby enabling uniform flow of refrigerant through multiple flow paths.

[0009] However, the technical problems that the present invention aims to solve are not limited to those described above, and other problems not mentioned can be clearly understood by an ordinary person of the art from the description of the invention below. [Means for solving the problem]

[0010] The present invention relates to a heat sink assembly in which a plurality of flow channels are integrally molded along the internal longitudinal direction by extrusion molding, the space between the flow channels forms a solid portion, the first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow channel include a heat sink separated from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, respectively, the first surface has both an inlet port for refrigerant to flow in and an outlet port for refrigerant to flow out, and the second surface forms a refrigerant return flow channel.

[0011] In one embodiment of the present invention, the inlet channel connected to the inlet port is located in the central region of the heat sink, the outlet ports are provided in pairs, and the outlet channels connected to the outlet ports may be located on both sides of the inlet channel.

[0012] The end plug may include an inlet plug that closes the first surface of the inlet channel, a pair of outlet plugs that close the first surface of the outlet channel, and a return plug that closes the second surface of the return channel.

[0013] On the other hand, the distance between the multiple outlet channels and the first surface may gradually decrease as they approach the outlet port.

[0014] For example, the distance from the first surface to the outlet channels may decrease linearly as they approach the outlet port.

[0015] The return channel described above may have a constant distance from the second surface.

[0016] In the above-mentioned multiple flow paths, the pressure loss acting on the refrigerant flowing through the return flow path on the second surface to each of the multiple outlet flow paths is proportional to the total length of the outlet flow path, thereby ensuring a uniform flow rate of the refrigerant flowing through each outlet flow path.

[0017] Furthermore, depending on the embodiment, an expanded solid portion may be provided between the inlet channel and the outlet channel adjacent to the inlet channel.

[0018] A pack structure can be mechanically bonded to the expanded solid section described above.

[0019] Furthermore, the longitudinal cross-sectional area formed by the space between the inlet plug and the inlet channel may be even larger than the longitudinal cross-sectional area of ​​the inlet channel.

[0020] Furthermore, the refrigerants flowing out from the pair of outlet ports mentioned above can be merged into one by a pipe component. [Effects of the Invention]

[0021] The heat sink assembly of the present invention, having the above configuration, possesses excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding. Furthermore, by machining both longitudinal ends of the flow channels integrally formed in the heat sink, and by closing the open surfaces with end plugs, it becomes possible to configure cooling channels that are divided into inlets and outlets.

[0022] As a result, the heat sink assembly of the present invention, while using an extruded heat sink as its basic framework which is advantageous in terms of structural rigidity, does not require separate pipes for flow path formation, occupies less space, and improves differential pressure by reducing the number of parts with a simplified flow path configuration. Furthermore, by uniformly guiding the flow rate of the refrigerant flowing through multiple flow paths, it is possible to ensure stable cooling performance across the entire heat dissipation area.

[0023] However, the technical effects that can be obtained by the present invention are not limited to those described above, and other effects not mentioned can be clearly understood by an ordinary person of the art from the description of the invention below.

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

[0025] [Figure 1] It is a drawing showing a heat sink assembly according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the heat sink assembly of FIG. 1. [Figure 3] It is a drawing showing the structure of the heat sink in detail. [Figure 4] It is a drawing showing an enlarged view of the "A" part of FIG. 1. [Figure 5] It is a drawing showing an enlarged view of the "B" part of FIG. 1. [Figure 6] It is a drawing showing the overall refrigerant flow in the heat sink assembly of FIG. 1. [Figure 7] It is a drawing showing an example in which a pack structure is coupled to the heat sink assembly of FIG. 1. [Figure 8] It is a drawing showing an embodiment in which a pair of outlet ports are interconnected by a pipe member.

[0026] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0027] However, this is not intended to limit the present invention to specific embodiments, and it can be understood as including all modifications, equivalents or alternatives included in the idea and technical scope of the present invention.

[0028] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof as described in the specification, and do not preemptively exclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Furthermore, in this invention, when a part such as a layer, film, region, or plate is described as being "on top" of another part, this includes not only the case where it is "directly on top" of the other part, but also the case where another part is located in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is located in between. Also, in this application, being "on top" may include being located not only at the top but also at the bottom.

[0030] The present invention relates to a heat sink assembly in which a plurality of channels are integrally molded along the internal longitudinal direction by extrusion molding, the space between the channels forms a solid portion, the first and second surfaces at both ends in the longitudinal direction are open, and both ends of the channel include a heat sink separated from the first and second surfaces, and end plugs that close the open first and second surfaces at both ends of the heat sink, respectively, the first surface has both an inlet port and an outlet port through which refrigerant flows in and out, and the second surface forms a refrigerant return channel.

[0031] The heat sink assembly of the present invention, having the above configuration, possesses excellent structural rigidity because the heat sink is manufactured as a continuous body by extrusion molding. Furthermore, by machining both longitudinal ends of the flow path integrally formed in the heat sink and closing the open surface with end plugs, it becomes possible to configure a cooling flow path divided into an inlet and an outlet.

[0032] As a result, the heat sink assembly of the present invention, while using an extruded heat sink as its basic framework, which is advantageous in terms of structural rigidity, does not require separate pipes for flow path formation, occupies less space, and can improve differential pressure by reducing the number of parts with a simplified flow path configuration.

[0033] Specific embodiments of the heat sink assembly 10 of the present invention will be described in detail below with reference to the attached drawings. For reference, the front-to-back and up-down-left-right directions used in the following description to specify relative positions are for the purpose of aiding the understanding of the invention, and unless otherwise defined, the directions shown in the drawings are used as the reference.

[0034] (First Embodiment) Figure 1 is a drawing showing a heat sink assembly 10 according to one embodiment of the present invention, Figure 2 is an exploded perspective view of the heat sink assembly 10 of Figure 1, and Figure 3 is a drawing showing the structure of the heat sink 100 in detail.

[0035] The heat sink assembly 10 of the present invention includes a heat sink 100 manufactured by extrusion molding and a plurality of end plugs 200. The open surfaces of the heat sink 100 are the surfaces at both ends in the longitudinal direction L, and for convenience of explanation, the two open surfaces are referred to as the first surface 130 and the second surface 140, respectively. Here, the longitudinal direction L is defined as the extrusion molding direction of the heat sink 100, that is, the direction in which the plurality of flow channels 110 formed in the hollow portion are extended, and the width direction W is defined as the direction perpendicular to the longitudinal direction L on a plane in which the plurality of flow channels 110 are spaced apart.

[0036] The heat sink 100 is manufactured from an extruded product in which multiple flow channels 110 are integrally molded along the internal longitudinal direction L by extrusion molding. The multiple flow channels 110 through which the coolant flows are hollow portions formed along the longitudinal direction L, and the space between the flow channels 110 forms a solid portion 120. The first surface 130 and the second surface 140 at both ends of the heat sink 100 in the longitudinal direction L are open due to the characteristics of extruded products.

[0037] Figure 3 shows the structure of the flow channels 110 in more detail. Multiple flow channels 110, which extend in the longitudinal direction L between the first surface 130 and the second surface 140, have their ends separated from the first surface 130 and the second surface 140 by a predetermined distance. The distance at which the flow channels 110 separate from the first surface 130 and the second surface 140 can be freely designed by machining to remove the hollow flow channels 110 and the solid portion 120 between them. Furthermore, by removing both the flow channels 110 and the solid portion 120 between them, a depth for inserting the end plug 200 is secured.

[0038] The end plugs 200 close the open first surface 130 and second surface 140 at both ends of the heat sink 100, respectively. The end plugs 200 have a thickness and width suitable for insertion into the openings on the first surface 130 and second surface 140 of the heat sink 100. The end plugs 200 inserted into the heat sink 100 can be sealed by welding, for example, friction stir welding. By ensuring that the welding depths of the friction stir welds performed on the upper and lower surfaces of the heat sink 100 overlap, a welded surface is formed on all four sides (top, bottom, left, and right) of the end plug 200, thereby completing the seal.

[0039] Since multiple flow paths 110 extend in the longitudinal direction L and the first surface 130 and the second surface 140 are sealed with end plugs 200, the refrigerant can be configured to flow over the entire heat transfer area of ​​the heat sink assembly 10 by suitably selecting the positions of the ports 300 through which the refrigerant flows in and out. In this invention, the first surface 130 has both an inlet port 310 for the refrigerant to flow in and an outlet port 320 for the refrigerant to flow out, and the second surface 140 has ports 300 arranged to form a refrigerant return flow path 116 without any separate ports.

[0040] Figure 4 is an enlarged view of section "A" in Figure 1. When viewed together with Figure 3, the inlet channel 112 connected to the inlet port 310 is located in the central region of the heat sink 100, a pair of outlet ports 320 are provided, and outlet channels 114 connected to the outlet ports 320 are located on both sides of the inlet channel 112 in the width direction W. In the illustrated embodiment, there are two inlet channels 112, and the ends of the inlet channels 112 are connected to return channels 116 which are formed along the second surface 140, and the return channels 116 are connected to the outlet channels 114 on both sides.

[0041] In one embodiment of the present invention, the end plug 200 that closes the first surface 130 includes an inlet plug 210 that closes the first surface 130 of the inlet flow path 112 and a pair of outlet plugs 220 that close the first surface 130 of the outlet flow path 114. A certain space is formed between the inlet plug 210 and the inlet flow path 112, and the inlet port 310 is positioned in this space. As a result, the refrigerant flowing into the inlet port 310 fills the space upstream of the inlet flow path 112 and then branches into each inlet flow path 112 and flows uniformly. Similarly, the outlet port 320 is positioned in the space between the outlet plug 220 and the outlet flow path 114.

[0042] Furthermore, the cross-sectional area in the longitudinal direction L formed by the space between the inlet plug 210 and the inlet flow path 112 may be even larger than the total cross-sectional area in the longitudinal direction L of the inlet flow path 112. By forming a kind of storage space between the inlet plug 210 and the inlet flow path 112, the flow of refrigerant introduced into the multiple inlet flow paths 112 can be made uniform and smooth.

[0043] Figure 5 is an enlarged view of section "B" in Figure 1, showing the return channel 116. The second surface 140 of the heat sink 100 is closed by the return plug 230, and the ends of each channel 110, that is, the ends of each channel 110 facing the second surface 140, are also separated from the return plug 230 by a predetermined distance, and the space thus formed forms the return channel 116. The return channel 116 can be formed as a channel 110 whose distance from the second surface 140 is constant, that is, a channel 110 with no substantial change in cross-sectional area.

[0044] On the other hand, in one embodiment of the present invention, one end of the outlet channel 114 directly connected to the outlet port 320 may be formed differently from the inlet channel 112 and the return channel 116. As shown in Figures 3 and 4, the distance from the first surface 130 of the multiple outlet channels 114 may gradually decrease as they approach the outlet port 320. For example, the distance from the first surface 130 of the multiple outlet channels 114 may decrease linearly as they approach the outlet port 320.

[0045] In the heat sink assembly 10 of the present invention, the flow area of ​​the outlet channel 114 is overwhelmingly larger than the flow area formed by the inlet channel 112 and the return channel 116. This is to ensure that when the refrigerant flows into the heat sink 100, the flow velocity in the outlet channel 114 decreases significantly, allowing heat to be transferred over a sufficient period of time. In other respects, the flow rate distribution of the refrigerant is also most greatly influenced by the outlet channel 114.

[0046] Due to the flow characteristics, the closer the inlet channel 112 is to the outlet channel 114, the lower the pressure loss acting on the refrigerant before it flows in. Therefore, the closer the inlet channel 112 is to the outlet channel 114, the more refrigerant tends to be introduced. Consequently, from the perspective of the illustrated heat sink assembly 10, the refrigerant is concentrated in the outlet channel 114 that is closer to the center, which reduces the heat transfer performance in the outer region. If the cooling performance of the heat sink assembly 10 varies depending on the region, there is a higher possibility of localized high-temperature regions occurring, which adversely affects the performance of the battery pack. Such variations in cooling performance can be resolved by ensuring a uniform flow rate of the refrigerant flowing through each outlet channel 114.

[0047] Figure 6 is a diagram showing the overall coolant flow in the heat sink assembly 10 of Figure 1. As described above, the multiple outlet channels 114 are configured such that the distance from the first surface 130 gradually decreases as they approach the outlet port 320. In other words, the length of each of the multiple outlet channels 114 gradually increases as they approach the outlet port 320, i.e., as they approach the inlet channel 112. In each outlet channel 114, the pressure loss acting on the coolant is proportional to the length of each outlet channel 114 that forms a boundary layer with the fluid. Therefore, the pressure loss acting on the refrigerant flowing through the return channel 116 of the second surface 140 to each outlet channel 114 is proportional to the total length of the outlet channel 114. As a result, the flow rate of the refrigerant gradually increases as it approaches the outer outlet channels 114, and the characteristic that more refrigerant is introduced the closer the inlet channel 112 is to the outlet channels 114 is offset, resulting in a uniform flow rate of refrigerant flowing through each outlet channel 114.

[0048] Thus, the heat sink assembly 10 according to the present invention exhibits uniform cooling characteristics without bias towards any particular region, as the coolant flows at a uniform rate across the entire surface area of ​​the heat sink 100.

[0049] (Second Embodiment) Figure 7 is a diagram showing an example of how the pack structure 400 is connected to the heat sink assembly 10 of Figure 1. Referring to Figures 1 to 5, an expanded solid portion 122 is provided between the inlet channel 112 and the outlet channel 114 adjacent to the inlet channel 112. Here, the expanded solid portion 122 refers to a solid portion 122 that is wider than, for example, the solid portion 120 that forms the gap between the channels 110. For example, the expanded solid portion 122 can be provided by forming a solid portion between the inlet channel 112 and the outlet channel 114 with a width that skips about one channel interval.

[0050] As shown in Figures 3 and 6, since the flow channels 110 are formed over almost the entire surface of the heat sink 100, in order to connect the heat sink assembly 10 of the present invention to a battery pack, it is necessary to provide a coupling structure that can maintain sufficient mechanical strength without damaging the flow channels 110. For this purpose, the heat sink assembly 10 is provided with a solid portion 122 that extends along the central longitudinal direction L.

[0051] For example, as shown in Figure 7, multiple screw holes 124 may be machined along the expanded solid portion 122, and a pack structure 400 (e.g., a center frame) may be firmly attached to the heat sink assembly 10 by bolts 410 fastened to the screw holes 124.

[0052] Figure 8 is a drawing showing an embodiment in which a pair of outlet ports 320 are interconnected by a pipe member 330. The present invention has two outlet ports 320 in terms of its flow path structure. Therefore, two external pipes connected to the outlet ports 320 are required, but as shown in Figure 8, by connecting a pair of outlet ports 320 with a pipe member 330 in the shape of the letter "Y" or "T", the refrigerant flowing out in two streams can be merged into one. The pipe member 330 that merges the two outlet ports 320 into one simplifies the external piping structure that needs to be made for the heat sink assembly 10.

[0053] The present invention has been described in more detail above through the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be various equivalents and modifications that can substitute for them at the time of filing. [Explanation of symbols]

[0054] 10: Heatsink Assembly 100: Heatsink 110: Flow channel 112: Inlet channel 114: Outlet channel 116: Return channel 120: Middle School 122: Extended solid section 124: Screw Hole 130: 1st page 140:Second side 200: End plug 210: Inlet Plug 220: Outlet plug 230: Return plug 300: Port 310: Inlet port 320: Outlet Port 330: Pipe components 400: Pack Structure 410: Bolt L: Long direction W: width direction

Claims

1. Multiple flow channels are integrally molded along the internal longitudinal direction by extrusion molding, the space between the flow channels forms a solid section, the first and second surfaces at both ends in the longitudinal direction are open, and both ends of the flow channels are separated from the first and second surfaces, forming a heat sink, and The heat sink includes end plugs that close the open first and second surfaces at both ends, respectively. The first surface has both an inlet port for refrigerant to flow in and an outlet port for refrigerant to flow out. A refrigerant return channel is formed on the second surface. The inlet channel connected to the inlet port is located in the central region of the heat sink. A heat sink assembly comprising a pair of outlet ports, with outlet channels connected to the outlet ports located on both sides of the inlet channel.

2. The aforementioned end plug is An inlet plug that closes the first surface of the inlet channel, A pair of outlet plugs that close the first surface of the outlet channel, and The heat sink assembly according to claim 1, further comprising a return plug for closing the second surface of the return channel.

3. Multiple outlet channels are, The heat sink assembly according to claim 1, wherein the distance from the first surface gradually decreases as it approaches the outlet port side.

4. The aforementioned multiple outlet channels are The heat sink assembly according to claim 3, wherein the distance from the first surface decreases linearly as it approaches the outlet port side.

5. The aforementioned return channel is The heat sink assembly according to claim 3, wherein the distance from the second surface is constant.

6. The aforementioned plurality of channels are The pressure loss acting on the refrigerant flowing through the return channel on the second surface to each of the multiple outlet channels is proportional to the total length of the outlet channels. The heat sink assembly according to claim 5, wherein the flow rate of the refrigerant flowing through each outlet channel becomes uniform.

7. The heat sink assembly according to claim 1, wherein an expanded solid portion is provided between the inlet channel and the outlet channel adjacent to the inlet channel.

8. The heat sink assembly according to claim 7, wherein a pack structure is mechanically coupled to the expanded solid portion.

9. The heat sink assembly according to claim 2, wherein the longitudinal cross-sectional area formed by the space between the inlet plug and the inlet channel is even larger than the longitudinal cross-sectional area of ​​the inlet channel.

10. The heat sink assembly according to claim 1, wherein the refrigerant flowing out from each of the pair of outlet ports is merged into one by a pipe member.

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