Battery pack and energy storage system

Abstract

The utility model relates to the technical field of heat exchange, and discloses a battery pack and an energy storage system. The battery pack comprises a cold plate and a battery module, the battery module comprises a plurality of battery monomers arranged in parallel, and the surface of the cold plate is in contact with the battery module. A flow channel is formed in the cold plate, and a first opening and a second opening are formed in the surface of one side of the cold plate. The flow channels comprise the liquid inlet flow channel and the liquid outlet flow channel, the liquid inlet flow channel spirally extends from the edge area where the first opening is located to the inner side area of the cold plate, and the liquid outlet flow channel spirally extends from the inner side area of the cold plate to the edge area where the second opening is located in the direction opposite to the extending track of the liquid inlet flow channel. The starting end of the liquid inlet flow channel communicates with the outside through the first opening, the tail end of the liquid inlet flow channel communicates with the starting end of the liquid outlet flow channel, and the tail end of the liquid outlet flow channel communicates with the outside through the second opening. And the cold plates can realize similar heat dissipation effects on different areas of the battery module, so that the temperature difference between the battery monomers is reduced, and the service life of the battery pack is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange, and in particular to a battery pack and an energy storage system. Background Art

[0002] With the continuous development of clean energy, energy storage systems for storing electrical energy have begun to be widely used in many fields. At present, there are more and more large-scale energy storage systems at the cabinet or container level, which can improve the energy storage capacity of the energy storage system by configuring more batteries.

[0003] The battery pack is the main device for storing and releasing electric energy in the energy storage system. As the capacity of battery cells increases, the energy density of the battery pack also increases significantly. In order to ensure the reliability of the battery pack, a heat sink is usually installed in the battery pack to dissipate heat. At present, the heat sink of the battery pack generally adopts liquid cooling. The flow channel design in the heat sink is simple, resulting in a large temperature difference between the battery cells in the battery pack, and the service life and consistency of the battery cells are poor. In addition, excessive temperature difference between battery cells may also cause thermal stress inside the battery pack, resulting in irreversible damage such as capacity loss and impedance increase of the battery pack. Utility Model Content

[0004] The utility model provides a battery pack and an energy storage system to improve the heat dissipation performance of the battery pack.

[0005] In the first aspect, the present application provides a battery pack, which includes a cold plate and a battery module, wherein the battery module includes a plurality of battery cells arranged in parallel, and the surface of the cold plate contacts the battery module so that the cold plate can dissipate heat from the battery module. The cold plate has a flow channel, and a first opening and a second opening are provided on one side surface of the cold plate, and the first opening and the second opening are both arranged near one side edge of the cold plate. The flow channel includes an inlet flow channel and an outlet flow channel, wherein the inlet flow channel extends in a spiral shape from the edge area where the first opening is located to the inner area of ​​the cold plate, and the outlet flow channel extends in a spiral shape from the inner area of ​​the cold plate to the edge area where the second opening is located in the reverse direction of the extension track of the inlet flow channel, or it can be understood that the extension track from the beginning of the inlet flow channel to the end of the inlet flow channel is roughly the extension track from the end of the outlet flow channel to the beginning of the outlet flow channel, the beginning of the inlet flow channel is connected to the outside through the first opening, the end of the inlet flow channel is connected to the beginning of the outlet flow channel, and the end of the outlet flow channel is connected to the outside through the second opening. Based on the spiral extension structure of the inlet and outlet channels, the inlet and outlet channels can flow through most areas of the cold plate, which is beneficial to increase the effective heat dissipation area of ​​the cold plate and enable the cold plate to achieve better heat dissipation effect. In addition, by extending the trajectory of the outlet channel in the opposite direction of the extension trajectory of the inlet channel, the distance between the outlet channel and the inlet channel will always be relatively close along the extension direction of the trajectory of the inlet or outlet channel, so that the coolant in the outlet channel can exchange heat with the coolant in the inlet channel, thereby reducing the temperature difference between the coolant in the outlet channel and the coolant in the inlet channel, achieving self-balancing of the cold plate temperature, and then improving the consistency of the temperature of each area of ​​the cold plate. In this way, the cold plate can achieve similar heat dissipation effects for different areas of the battery module, which is beneficial to reduce the temperature difference between battery cells and extend the service life of the battery pack.

[0006] In some embodiments, there may be multiple inlet channels and multiple outlet channels, multiple inlet channels are arranged in parallel, the beginning of each inlet channel is connected to the first opening, the end of each inlet channel is connected to the beginning of the corresponding outlet channel, and the end of each outlet channel is connected to the second opening. Multiple parallel channels can reduce the flow resistance of the cold plate, thereby improving the heat exchange efficiency of the cold plate. A cold plate with this design can achieve good heat dissipation effect for large-sized and high-energy-density battery packs.

[0007] In some embodiments, the extension trajectories of the liquid inlet channel and the liquid outlet channel can both be in the shape of a U-shaped character. The liquid inlet channel includes a plurality of first transverse channels and a plurality of first vertical channels, and the plurality of first transverse channels and the plurality of first vertical channels are connected alternately end to end in sequence, and the starting end of the first first vertical channel is the starting end of the liquid inlet channel. The liquid outlet channel includes a plurality of second transverse channels and a plurality of second vertical channels, and the plurality of second transverse channels and the plurality of second vertical channels are connected alternately end to end in sequence, and the end of the last second vertical channel is the end of the liquid outlet channel. Among them, the first vertical channel and the second vertical channel extend along the width direction of the battery pack, respectively, and the first transverse channel and the second transverse channel extend along the length direction of the battery pack, respectively. Since the first opening and the second opening are both arranged close to the edge of the cold plate, the first first vertical channel and the last second vertical channel are also located close to the edge area of ​​the cold plate, so that the edge area of ​​the cold plate can also achieve a better heat dissipation effect.

[0008] In some embodiments, the first first vertical flow channel and the last second vertical flow channel are arranged along the width direction of the battery pack, and the starting end of the first first vertical flow channel and the end of the last second vertical flow channel are opposite to each other along the width direction of the battery pack, and the distance between the first vertical flow channel and the edge of the cold plate is approximately equal to the distance between the last second vertical flow channel and the edge of the cold plate, so that the opening positions of the first opening and the second opening can be relatively concentrated, thereby helping to increase the effective heat dissipation area of ​​the cold plate.

[0009] In some embodiments, the cold plate includes a first plate body and a second plate body, the first plate body includes a first surface, the flow channel can be arranged on the first surface of the first plate body, and the second plate body is covered on the first surface of the first plate body, so that the flow channel is closed between the first plate body and the second plate body. In addition, the first opening can be arranged at a position of the second plate body opposite to the starting end of the liquid inlet flow channel, and the second opening can be arranged at a position of the second plate body opposite to the end of the liquid outlet flow channel, so as to facilitate the flow channel to be connected with the outside.

[0010] In one implementation, the flow channel can be formed on the first surface of the first plate body by stamping. This process is simple and has high production efficiency, which facilitates the mass production of the cold plate.

[0011] In some embodiments, the battery pack may further include a frame, a first connecting tube and a second connecting tube. The frame may be arranged around the cold plate, and the side wall of the frame may be provided with a first through hole and a second through hole. The first connecting tube and the second connecting tube are respectively arranged on the side of the second plate body facing away from the first plate body, one end of the first connecting tube is connected to the first opening, and the other end of the first connecting tube is connected to the outside through the first through hole, one end of the second connecting tube is connected to the second opening, and the other end of the second connecting tube is connected to the outside through the second through hole. The use of the first connecting tube and the second connecting tube can improve the simplicity and sealing of the connection between the first opening and the second opening and the external cooling device.

[0012] In one implementation, the inner wall of the frame includes a flange, which can be supported on an edge of the second plate body facing away from the first plate body, thereby facilitating assembly of the cold plate and the frame. Exemplarily, the flange, the first plate body, and the second plate body can be connected by a flow drill screw process.

[0013] In some embodiments, the battery pack may further include one or more reinforcing beams, which are disposed on the side of the first plate body facing away from the second plate body, and each reinforcing beam extends along the width direction of the battery pack. The reinforcing beams can improve the structural strength of the cold plate and reduce the risk of the cold plate deforming under load.

[0014] In some embodiments, a surface of the first plate body on one side facing away from the second plate body may be coated with a heat insulation coating to improve the heat preservation effect of the cold plate and reduce the risk of condensation on the cold plate.

[0015] In some embodiments, the battery modules can be stacked on a cold plate, that is, the battery pack uses bottom cooling to dissipate heat. This heat dissipation method can increase the contact area between the battery module and the cold plate, thereby helping to improve the heat dissipation effect on the battery module.

[0016] In the second aspect, the present application also provides an energy storage system, which includes a power converter and an energy storage device, the energy storage device includes a plurality of battery packs in any of the embodiments of the first aspect, and the plurality of battery packs are connected in series or in parallel. The power converter and the energy storage device are electrically connected, and the power converter is used to convert AC power into DC power and input it into the energy storage device, and / or convert the DC power output by the energy storage device into AC power and then output it, so that the energy storage system can realize the functions of energy storage and external power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An application scenario diagram of an energy storage system provided by an embodiment of the utility model;

[0018] Figure 2 A schematic diagram of the exploded structure of a battery pack provided in an embodiment of the utility model;

[0019] Figure 3 A schematic diagram of the structure of a heat dissipation device provided by an embodiment of the utility model;

[0020] Figure 4 A schematic diagram of a partial structure of a cold plate provided in an embodiment of the utility model;

[0021] Figure 5 for Figure 4 Schematic diagram of the flow direction of the coolant in the cold plate shown in ;

[0022] Figure 6A schematic diagram of the partial structure of another cold plate provided in an embodiment of the utility model;

[0023] Figure 7 for Figure 6 Schematic diagram of the flow direction of the coolant in the cold plate shown in ;

[0024] Figure 8 A schematic diagram of the flow direction of coolant in another cold plate provided in an embodiment of the utility model.

[0025] Reference numerals:

[0026] 1000 - battery pack; 100 - battery module; 110 - battery cell; 200 - heat sink; 210 - cold plate; 2101 - first side of cold plate;

[0027] 211-flow channel; 2111-liquid inlet flow channel; 2111a-starting end of the liquid inlet flow channel; 2111b-end of the liquid inlet flow channel; 21111-first transverse flow channel;

[0028] 21112-first vertical flow channel; 2112-liquid outlet flow channel; 2112a-starting end of the liquid outlet flow channel; 2112b-end of the liquid outlet flow channel;

[0029] 21121 - second transverse flow channel; 21122 - second vertical flow channel; 214 - first plate body; 2141 - first surface of the first plate body;

[0030] 2142 - second surface of the first plate; 215 - second plate; 212 - first opening; 213 - second opening; 220 - surrounding frame; 221 - flange;

[0031] 222 - first through hole; 223 - second through hole; 230 - fixed beam; 231 - avoidance groove; 240 - first connecting pipe; 250 - second connecting pipe;

[0032] 260- reinforcing beam; 270- connecting block; 300- outer cover. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the utility model clearer, the embodiments of the utility model will be further described in detail in conjunction with the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the embodiments of the utility model are all explained with the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the utility model. The drawings of the embodiments of the utility model are only used to illustrate the relative position relationship and do not represent the true proportion.

[0034] It should be noted that specific details are described in the following description to facilitate understanding of the present invention. However, the embodiments of the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the embodiments of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Energy storage system is a device that can store electrical energy through a certain medium and release the stored energy to generate electricity when needed. Energy storage system can be applied to five types of industrial and commercial energy storage scenarios, including small-scale industry and commerce (such as small factories, etc.), medium-sized industry and commerce, large-scale industry and commerce, photovoltaic storage and charging stations, and small and medium-sized microgrids (such as islands, etc.), as well as three types of power station scenarios, including wind and solar energy storage power stations, grid energy storage power stations, and large microgrids.

[0036] like Figure 1 As shown, Figure 1 An application scenario diagram of an energy storage system provided for an embodiment of the utility model. The energy storage system includes an energy storage device and a power converter. The energy storage device is used to receive electric energy generated by a power generation device. The power converter is used to convert the direct current output by the energy storage device into alternating current and then output it to a power grid or an external load. Alternatively, the power converter is used to convert alternating current into alternating current and input it to the energy storage device. The energy storage device may include a plurality of battery packs, and the plurality of battery packs may be connected in series or in parallel. The power generation device may be a photovoltaic power generation device, and the battery pack may be connected to a photovoltaic module of the photovoltaic power generation device.

[0037] Figure 2 This is a schematic diagram of the exploded structure of the battery pack 1000 provided in an embodiment of the present utility model. Figure 2 As shown, in the embodiment of the utility model, the battery pack 1000 may include a battery module 100, a heat sink 200 and an outer cover 300. The surface of the heat sink 200 contacts the battery module 100. The heat sink 200 can absorb the heat generated by the battery module 100 during the charging and discharging process and transfer the heat to the outside, thereby realizing heat dissipation of the battery module 100. In one implementation, the battery module 100 can be stacked on the heat sink 200, that is, the battery module 100 and the heat sink 200 are assembled in an up-down distribution manner, and the heat sink 200 dissipates heat for the battery module 100 at the bottom of the battery module 100, so that the battery pack 1000 realizes a bottom-cooling heat dissipation architecture. The outer cover 300 is connected to the surface of one side of the heat sink 200 that carries the battery module 100, so that the battery module 100 is covered in the accommodation space formed by the outer cover 300 and the heat sink 200, so as to realize the protection of the battery module 100 and reduce the erosion and damage of the battery module 100 by the external environment.

[0038] The battery pack 1000 may include one or more battery modules 100 , and each battery module 100 may include one or more battery cells 110 , for example. Figure 2 , an example is shown in which a battery pack 1000 includes a plurality of battery modules 100, and each battery module 100 includes a plurality of battery cells 110. The plurality of battery cells 110 in each battery module 100 may be connected in series or in parallel, and the plurality of battery modules 100 may be connected in series, so as to replenish electric energy for each battery cell 110 during the charging process of the battery pack 1000, or to release electric energy for each battery cell 110 during the discharging process of the battery pack 1000. The plurality of battery modules 100 in the battery pack 1000 may be arranged in sequence along a first direction x, and the plurality of battery cells 110 in each battery module 100 may be arranged in sequence along a second direction y, so as to reduce the difficulty of connecting adjacent battery cells 110 and adjacent battery modules 100. Exemplarily, the first direction x and the second direction y may be perpendicular to each other, and exemplary, the first direction x may be arranged in sequence along the width direction of the battery pack 1000, and the second direction y may be the length direction of the battery pack 1000.

[0039] Figure 3 This is a schematic diagram of the structure of a heat dissipation device 200 provided in an embodiment of the utility model. Figure 2 and Figure 3 As shown, in an embodiment of the utility model, the heat dissipation device 200 includes a cold plate 210, and a flow channel 211 is provided in the cold plate 210, and the flow channel 211 can be used to circulate the coolant. One side surface of the cold plate 210 includes a first opening 212 and a second opening 213, and the two ends of the flow channel 211 can be connected to an external cooling device through the first opening 212 and the second opening 213 respectively. The external cooling device includes a heat exchanger, a refrigerator or an air conditioner, etc. The external cooling device can transport low-temperature coolant to the flow channel 211 through the first opening 212. The temperature of the low-temperature coolant in the flow channel 211 increases after heat exchange with the battery module 100, and then returns to the external cooling device through the second opening 213 for cooling, completing a cycle. At the same time, the battery module 100 is cooled by transferring heat to the coolant.

[0040] In this embodiment, the first opening 212 and the second opening 213 can be located at one side edge of the cold plate 210 to reduce the difficulty of connecting the cold plate 210 to the pipeline of the external device. For example, the first opening 212 and the second opening 213 can be arranged close to the edge of the first side 2101 of the cold plate 210. The first side 2101 of the cold plate 210 can be one side of the cold plate 210 perpendicular to the second direction y.

[0041] Continue to refer Figure 3As shown, in the embodiment of the utility model, the cold plate 210 includes a first plate body 214 and a second plate body 215, wherein the first plate body 214 includes a first surface 2141 and a second surface 2142 disposed opposite to each other, the first surface 2141 of the first plate body 214 can be used to form the above-mentioned flow channel 211, and the second plate body 215 can be covered on the first surface 2141 of the first plate body 214, so as to close the flow channel 211 between the first plate body 214 and the second plate body 215. Exemplarily, the second plate body 215 and the first plate body 214 can be fixed by welding to improve the sealing of the flow channel 211. The first opening 212 and the second opening 213 can be respectively disposed at two positions of the second plate body 215 opposite to the two ends of the flow channel 211, and the first opening 212 and the second opening 213 respectively penetrate the second plate body 215, so as to connect the flow channel 211 with the outside.

[0042] In one implementation, the first surface 2141 of the first plate 214 can be formed into the flow channel 211 by stamping. In this case, the first surface 2141 of the first plate 214 is partially recessed to form the flow channel 211, and the second surface 2142 of the first plate 214 is convex outward at a position corresponding to the flow channel 211. This process is simple and has high production efficiency, which facilitates mass production of the heat dissipation device 200. Of course, in some other implementations, the first plate 214 can also form the flow channel by removing material or the like.

[0043] In the embodiment of the utility model, the side surface of the second plate 215 facing away from the first plate 214 can be used as the side surface of the heat sink 200 in contact with the battery module 100, and the heat generated by the battery module 100 can be transferred to the coolant in the flow channel 211 through the second plate 215. Since the surface of the second plate 215 is relatively flat, it can form a good contact with the battery module 100, which is conducive to improving the heat transfer efficiency between the battery module 100 and the heat sink 200. In addition, the side surface of the first plate 214 facing away from the second plate 215 can be coated with a heat insulation coating to improve the heat preservation effect of the heat sink 200 and reduce the risk of condensation of the heat sink 200.

[0044] In some embodiments, the heat dissipation device 200 further includes a frame 220, which can be arranged around the edge of the cold plate 210. In a specific implementation, the inner wall of the frame 220 includes a flange 221, which can be supported on a side edge of the second plate 215 facing away from the first plate 214, thereby facilitating the assembly of the cold plate 210 and the frame 220. In addition, the heat dissipation device 200 can also include two fixed beams 230, which can be arranged on a side of the first plate 214 facing away from the second plate 215, the two fixed beams 230 are arranged along the first direction x, and the two fixed beams 230 extend respectively along the second direction y, and each fixed beam 230 is arranged on a side edge of the first plate 214. The height direction of the battery pack is defined as the third direction z. Along the third direction z, the flange 221, the second plate 215, the first plate 214, and the fixed beam 230 are arranged in sequence. That is, the edge of the cold plate 210 is pressed between the flange 221 and the fixed beam 230, and the flange 221, the first plate 214, the second plate 215, and the fixed beam 230 can be connected by a flow drill screw (FDS) process.

[0045] In this embodiment, the side wall of the frame 220 corresponding to the first side 2101 of the cold plate 210 is provided with a first through hole 222 and a second through hole 223, the first opening 212 can be communicated with the outside through the first through hole 222, and the second opening 213 can be communicated with the outside through the second through hole 223. In one implementation, the heat dissipation device 200 further includes a first connecting tube 240 and a second connecting tube 250, which are respectively arranged on a side of the second plate body 215 facing away from the first plate body 214. The first connecting tube 240 and the second connecting tube 250 can both be approximately L-shaped structures, one end of the first connecting tube 240 is connected to the first opening 212, and the other end of the first connecting tube 240 can be inserted into the first through hole 222 to facilitate communication with an external cooling device through the first through hole 222, one end of the second connecting tube 250 is connected to the second opening 213, and the other end of the second connecting tube 250 can be inserted into the second through hole 223 to facilitate communication with an external cooling device through the second through hole 223.

[0046] Exemplarily, one end of the first connecting tube 240 is welded and fixed to a surface of the second plate 215 on one side facing away from the first plate 214, so as to improve the sealing performance of the connection between the first connecting tube 240 and the first opening 212. Similarly, one end of the second connecting tube 250 is welded and fixed to a surface of the second plate 215 on one side facing away from the first plate 214, so as to improve the sealing performance of the connection between the second connecting tube 250 and the second opening 213.

[0047] In some embodiments, the heat dissipation device 200 includes a reinforcing beam 260, which is fixed to the second surface 2142 of the first plate body 214, and the reinforcing beam 260 can extend along the first direction x. The reinforcing beam 260 can improve the structural strength of the cold plate 210 and reduce the risk of the cold plate 210 deforming under load. It should be noted that when the heat dissipation device 200 includes a fixed beam 230, the fixed beam 230 can be located on the side of the reinforcing beam 260 that is away from the second plate body 215, that is, the end of the reinforcing beam 260 can be located between the first plate body 214 and the fixed beam 230, so that the connection strength between the reinforcing beam 260 and the first plate body 214 can be improved by the fixed beam 230. In addition. A avoidance groove 231 can be set at the position of the fixed beam 230 corresponding to the end of the reinforcing beam 260 to avoid the reinforcing beam 260 and improve the structural compactness of the heat dissipation device 200.

[0048] The number of the reinforcing beam 260 may be one or more, for example Figure 3 2 shows an example in which the heat dissipation device 200 includes four reinforcing beams 260. In the case where there are multiple reinforcing beams 260, the multiple reinforcing beams 260 can be distributed at intervals along the second direction y, thereby achieving structural reinforcement of the cold plate 210 at multiple locations, which helps to further improve the reliability of the cold plate 210.

[0049] In one implementation, the heat dissipation device 200 may further include a plurality of connection blocks 270 respectively arranged corresponding to each reinforcing beam 260, the plurality of connection blocks 270 may be welded to the second surface 2142 of the first plate 214, and the plurality of connection blocks 270 are spaced apart along the first direction x, and the reinforcing beam 260 may be fixed to the first plate 214 by connecting with the plurality of connection blocks 270. Exemplarily, the reinforcing beam 260 and the connection block 270 may be fixedly connected by fasteners. It is worth mentioning that in the case where the first plate 214 forms a flow channel by a stamping process, the connection block 270 may be arranged in an unprotruded area of ​​the second surface 2142 of the first plate 214, that is, the projection of the connection block 270 in the third direction z does not overlap with the projection of the flow channel 211 in the third direction z, so as to increase the welding area between the connection block 270 and the first plate 214, thereby helping to improve the connection reliability between the reinforcing beam 260 and the first plate 214.

[0050] Figure 4 A partial structural schematic diagram of a cold plate 210 provided in an embodiment of the utility model, Figure 5 for Figure 4 Schematic diagram of the flow direction of the cooling liquid in the cold plate 210 shown in FIG. Figure 4 FIG. 2 shows the structure of the area where the flow channel 211 is located, and other areas of the cold plate 210 are not shown. Figure 4 and Figure 5As shown, in the embodiment of the utility model, the flow channel 211 includes an inlet flow channel 2111 and an outlet flow channel 2112. The inlet flow channel 2111 extends spirally from the edge area where the first opening is located to the inner area of ​​the cold plate 210, and the outlet flow channel 2112 extends spirally from the inner area of ​​the cold plate 210 to the edge area where the second opening is located in the reverse direction of the extension trajectory of the inlet flow channel 2111. Alternatively, it can be understood that the extension trajectory from the starting end of the inlet flow channel 2111 to the end of the inlet flow channel 2111 is roughly the extension trajectory from the end of the outlet flow channel 2112 to the starting end of the outlet flow channel 2112. For ease of distinction, Figure 4 The lines of the liquid outlet channel 2112 are darkened. Figure 5 The solid line indicates the flow direction of the coolant in the liquid inlet channel 2111 , and the dotted line indicates the flow direction of the coolant in the liquid outlet channel 2112 .

[0051] When the first opening and the second opening are both arranged at the edge of the first side 2101 of the cold plate 210, the starting end 2111a of the liquid inlet channel 2111 is located at the edge of the first side 2101 of the cold plate 210, the end 2111b of the liquid inlet channel 2111 is located at the inner area of ​​the cold plate 210, the starting end 2112a of the liquid outlet channel 2112 is located at the inner area of ​​the cold plate 210, and the end of the liquid outlet channel 2112 is located at the edge of the first side 2101 of the cold plate 210. The starting end 2111a of the inlet channel 2111 and the end 2112b of the outlet channel 2112 are respectively the inlet port and the outlet port of the entire channel 211; the starting end 2111a of the inlet channel 2111 is connected to the outside through the aforementioned first opening; the end 2112b of the outlet channel 2112 is connected to the outside through the aforementioned second opening; the end 2111b of the inlet channel 2111 is connected to the starting end 2112a of the outlet channel 2112. The coolant enters the liquid inlet channel 2111 through the starting end 2111a of the liquid inlet channel 2111, gradually flows along the extension trajectory of the liquid inlet channel 2111 toward the end 2111b of the liquid inlet channel 2111, and exchanges heat with the battery module during the flow, then enters the liquid outlet channel 2112, flows along the extension trajectory of the liquid outlet channel 2112 toward the end 2112b of the liquid outlet channel 2112, and exchanges heat with the battery module during the flow, and finally flows out of the heat dissipation device from the end 2112b of the liquid outlet channel 2112.

[0052] Based on the spiral extension structure of the inlet flow channel 2111 and the outlet flow channel 2112, the inlet flow channel 2111 and the outlet flow channel 2112 can flow through most areas of the cold plate 210, which is beneficial to increase the effective heat dissipation area of ​​the cold plate 210, so that the cold plate 210 can achieve a better heat dissipation effect. Since the coolant is constantly exchanging heat with the battery module during the process of flowing from the inlet flow channel 2111 to the outlet flow channel 2112, the temperature of the coolant will gradually increase as the distance the coolant flows, so the temperature of the coolant in the outlet flow channel 2112 will be higher than the temperature of the coolant in the inlet flow channel 2111. By making the track of the liquid outlet channel 2112 extend in the opposite direction of the extension track of the liquid inlet channel 2111, the distance between the liquid outlet channel 2112 and the liquid inlet channel 2111 will always be relatively close along the extension direction of the track of the liquid inlet channel 2111 or the liquid outlet channel 2112, so that the coolant in the liquid outlet channel 2112 can exchange heat with the coolant in the liquid inlet channel 2111, thereby reducing the temperature difference between the coolant in the liquid outlet channel 2112 and the coolant in the liquid inlet channel 2111, achieving self-balancing of the temperature of the cold plate 210, and then improving the consistency of the temperature of each area of ​​the cold plate 210. Thanks to this, the cold plate 210 can achieve similar heat dissipation effects on different parts of the battery module, which is beneficial to reducing the temperature difference between battery cells and extending the service life of the battery pack.

[0053] Please continue to refer to Figure 4 and Figure 5 In some embodiments, the extension trajectory of the liquid inlet channel 2111 can be a U-shape, and the liquid inlet channel 2111 includes a plurality of first transverse channels 21111 and a plurality of first vertical channels 21112. The plurality of first transverse channels 21111 and the plurality of first vertical channels 21112 are connected alternately end to end in sequence, and the starting end of the first first vertical channel 21112 is the starting end 2111a of the liquid inlet channel 2111. That is to say, the starting end of the first first vertical channel 21112 is connected to the first opening as the liquid inlet port of the entire channel 211. Similarly, the extension trajectory of the liquid outlet channel 2112 can also be a U-shape, and the liquid outlet channel 2112 includes multiple second horizontal channels 21121 and multiple second vertical channels 21122. The multiple second horizontal channels 21121 and the multiple second vertical channels 21122 are alternately connected end to end in sequence, and the end of the last second vertical channel 21122 is the end 2112b of the liquid outlet channel 2112. That is to say, the end of the second vertical channel 21122 serves as the liquid outlet port of the entire channel 211 and is connected to the second opening.

[0054] The first vertical channel 21112 and the second vertical channel 21122 extend along the width direction of the heat sink, that is, along the first direction x; the first transverse channel 21111 and the second transverse channel 21121 extend along the length direction of the heat sink, that is, along the second direction y. Figure 2 and Figure 3 As shown, the first opening 212 and the second opening 213 are both disposed close to the first side 2101 of the cold plate 210 , so the first first vertical flow channel 21112 and the last second vertical flow channel 21122 are also located in a region close to the first side 2101 of the cold plate 210 .

[0055] In one implementation, the first vertical channel 21112 and the last second vertical channel 21122 are arranged along the second direction, and the starting end of the first vertical channel 21112 and the end of the last second vertical channel 21122 are opposite to each other along the first direction x, or it can be understood that the first vertical channel 21112 can be located on the extension line of the last second vertical channel 21122. With this design, the distance between the first vertical channel 21112 and the first side 2101 of the cold plate 210 is roughly equal to the distance between the last second vertical channel 21122 and the first side 2101 of the cold plate 210, which can make the positions of the first opening and the second opening closer to the edge of the cold plate 210, and can also make the opening positions of the first opening and the second opening relatively concentrated, thereby helping to increase the effective heat dissipation area of ​​the cold plate 210.

[0056] In the embodiment of the utility model, the liquid inlet channel 2111 and the liquid outlet channel 2112 can be multiple, such as Figure 4 An example in which there are three liquid inlet channels 2111 and three liquid outlet channels 2112 is shown. Multiple liquid inlet channels 2111 are arranged in parallel along the extension direction of the liquid inlet channel 2111, and the starting end 2111a of each liquid inlet channel 2111 is respectively connected to the first opening, and multiple liquid outlet channels 2112 are arranged in parallel along the extension direction of the liquid outlet channel 2112, and the end 2112b of each liquid outlet channel 2112 is respectively connected to the second opening. In other words, multiple liquid inlet channels 2111 are arranged in parallel, and multiple liquid outlet channels 2112 are arranged in parallel. When the supply amount of coolant is constant, multiple parallel channels can reduce the flow resistance of the cold plate 210, thereby improving the heat exchange efficiency of the cold plate 210. A cold plate with such a design can achieve good heat dissipation effect for large-sized and high-energy-density battery packs.

[0057] In addition, when there are multiple liquid inlet channels 2111 and multiple liquid outlet channels 2112, the liquid outlet channel 2112 closest to the liquid inlet channel 2111 among the multiple liquid outlet channels 2112 can reduce the temperature difference by heat exchange with the liquid inlet channel 2111, and the liquid outlet channel 2112 adjacent to it can reduce the temperature difference by heat exchange with the liquid outlet channel 2112 close to the liquid inlet channel 2111. By transferring the cold amount in this way in sequence, the self-balancing of the temperature of the cold plate 210 can be achieved.

[0058] It is easy to understand that the fewer the number of flow channels 211, the more spiral turns the flow channel 211 can have, which can increase the length of the flow channel 211 to a certain extent, and the longer the length of the flow channel 211, the greater the flow resistance of the flow channel 211. Correspondingly, the more the number of flow channels 211, the fewer the number of spiral turns the flow channel 211 has, which can reduce the length of the flow channel 211 to a certain extent, and the shorter the length of the flow channel 211, the smaller the flow resistance of the flow channel 211. Based on this, in actual applications, the number of liquid inlet flow channels 2111 and liquid outlet flow channels 2112 can be designed according to actual product requirements to match the heat dissipation requirements of the battery pack and ensure the reliability of the battery pack.

[0059] For example, Figure 6 An example in which there are two liquid inlet channels 2111 and two liquid outlet channels 2112 is shown. Figure 7 for Figure 6 Schematic diagram of the flow direction of the cooling liquid in the cold plate 210 shown in FIG. Figure 6 The form of the flow channel 211 shown in FIG. 2 is applicable to scenarios where the flow resistance of the cold plate 210 is required to be relatively large.

[0060] Another example: Figure 8 The figure shows the flow direction of the coolant when there are four inlet channels 2111 and four outlet channels 2112. Figure 8 The form of the flow channel 211 shown in FIG. 2 is applicable to scenarios where the flow resistance of the cold plate 210 is required to be relatively small.

[0061] The above are only specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A battery pack, characterized in that: The battery pack includes a cold plate and a battery module, the battery module includes a plurality of battery cells, and the surface of the cold plate contacts the battery module to dissipate heat for the battery module; The cold plate has a flow channel, and a first opening and a second opening are provided on one side surface of the cold plate, the first opening and the second opening are both provided close to one side edge of the cold plate, the flow channel includes a liquid inlet flow channel and a liquid outlet flow channel, wherein: The liquid inlet channel extends in a spiral shape from the edge area where the first opening is located to the inner area of ​​the cold plate, and the liquid outlet channel extends in a spiral shape from the inner area of ​​the cold plate to the edge area where the second opening is located in the opposite direction of the extension trajectory of the liquid inlet channel. The starting end of the liquid inlet channel is connected to the outside through the first opening, the end of the liquid inlet channel is connected to the starting end of the liquid outlet channel, and the end of the liquid outlet channel is connected to the outside through the second opening.

2. The battery pack according to claim 1, characterized in that: There are multiple liquid inlet channels and multiple liquid outlet channels, and the multiple liquid inlet channels are arranged in parallel. The starting end of each liquid inlet channel is connected to the first opening, the end of each liquid inlet channel is connected to the starting end of the corresponding liquid outlet channel, and the end of each liquid outlet channel is connected to the second opening.

3. The battery pack according to claim 1, wherein: The liquid inlet flow channel comprises a plurality of first transverse flow channels and a plurality of first vertical flow channels, the plurality of first transverse flow channels and the plurality of first vertical flow channels are connected end to end alternately in sequence, and the starting end of the first of the first vertical flow channels is the starting end of the liquid inlet flow channel; The liquid outlet flow channel comprises a plurality of second transverse flow channels and a plurality of second vertical flow channels, the plurality of second transverse flow channels and the plurality of second vertical flow channels are connected end to end in sequence alternately, and the end of the last second vertical flow channel is the end of the liquid outlet flow channel; The first transverse flow channel and the second transverse flow channel respectively extend along the length direction of the battery pack, and the first vertical flow channel and the second vertical flow channel respectively extend along the width direction of the battery pack.

4. The battery pack according to claim 3, characterized in that: The first of the first vertical flow channels and the last of the second vertical flow channels are arranged along the width direction of the battery pack, and the starting end of the first of the first vertical flow channels and the ending end of the last of the second vertical flow channels are opposite to each other along the width direction of the battery pack.

5. The battery pack according to any one of claims 1 to 4, characterized in that: The cold plate includes a first plate body and a second plate body, the flow channel is arranged on the first surface of the first plate body, the second plate body cover is arranged on the first surface of the first plate body, the first opening is arranged at a position where the second plate body is opposite to the starting end of the liquid inlet flow channel, and the second opening is arranged at a position where the second plate body is opposite to the end of the liquid outlet flow channel.

6. The battery pack according to claim 5, characterized in that: The battery pack comprises a surrounding frame, a first connecting pipe and a second connecting pipe, the surrounding frame is arranged around the cold plate, and a first through hole and a second through hole are arranged on a side wall of the surrounding frame; The first connecting tube and the second connecting tube are respectively arranged on a side of the second plate body facing away from the first plate body, one end of the first connecting tube is connected to the first opening, and the other end of the first connecting tube is connected to the outside through the first through hole; one end of the second connecting tube is connected to the second opening, and the other end of the second connecting tube is connected to the outside through the second through hole.

7. The battery pack according to claim 5, characterized in that: The battery pack includes one or more reinforcing beams, which are arranged on a side of the first plate body facing away from the second plate body, and each of the reinforcing beams extends along a width direction of the battery pack.

8. The battery pack according to claim 5, characterized in that: A heat-insulating coating is coated on a surface of the first plate body facing away from the second plate body.

9. The battery pack according to any one of claims 1 to 4, characterized in that: The battery modules are stacked on top of the cold plate.

10. An energy storage system, characterized in that: It comprises a power converter and an energy storage device, wherein the energy storage device comprises a plurality of battery packs according to any one of claims 1 to 9 connected in series or in parallel, and the power converter is electrically connected to the energy storage device; The power converter is used to convert alternating current into direct current and input it into the energy storage device, and / or the power converter is used to convert direct current output by the energy storage device into alternating current.

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