Battery pack and cooling system

Abstract

The utility model provides a battery pack and a cooling system, and the battery pack comprises a battery core stacking body which comprises a plurality of mutually stacked battery cores; the cold plates comprise a first cold plate and a second cold plate, and the first cold plate and the second cold plate are respectively arranged on the top surface and the bottom surface of the cell stack body; at least one of the first cold plate and the second cold plate comprises a first sub-cold plate and a second sub-cold plate, the first sub-cold plate and the second sub-cold plate are stacked in the thickness direction of the cold plate, a liquid cooling flow channel is formed in the first sub-cold plate, a direct cooling flow channel is formed in the second sub-cold plate, cooling liquid circulates in the liquid cooling flow channel, and a refrigerant circulates in the direct cooling flow channel; and the first sub cold plate is in contact with the cell stack. According to the utility model, the cold plates are arranged on the top surface and the bottom surface of the battery cell stacking body, and the cold plate on the top surface and the cold plate on the bottom surface are connected in parallel, so that the problem of low refrigeration efficiency is solved, the cooling effect on the battery is improved, the efficient thermal management effect is ensured, and the temperature difference in the height direction of the battery cell can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of cooling systems, in particular to a battery pack and a cooling system. Background Art

[0002] The temperature of existing batteries during the charging and discharging process is getting higher and higher, and the heating rate is getting faster and faster. If the battery works in a high temperature environment for a long time, it will lead to the intensification of the side reactions inside the battery, which will not only affect the service life of the battery cell, but also increase the probability of thermal runaway of the battery. The decay of battery service life and the risk of thermal runaway greatly affect the user experience of electric vehicles. Therefore, the battery packs equipped with new energy vehicles are generally designed with a cooling system to remove the heat accumulated during the use of the battery cell to ensure that the battery operates within the appropriate temperature range.

[0003] The existing battery pack cooling system circuit generally includes components such as a water pump, a liquid cooling plate, a plate heat exchanger, and a liquid storage pot. When the cooling system is working, the high-temperature coolant flows out of the outlet of the liquid cooling plate and enters the plate heat exchanger. After the high-temperature coolant exchanges heat with the low-temperature refrigerant, it flows out of the plate heat exchanger and enters the inlet of the liquid cooling plate. It has certain defects. The low-temperature refrigerant does not directly participate in the heat exchange process of the battery, so it cannot directly take away the heat from the battery when it is working. Instead, it needs to exchange heat with the coolant after the heat exchange between the coolant and the battery is completed, and then the refrigerant and the coolant are used to exchange heat to indirectly take away the heat. This two-stage heat exchange mode causes part of the heat generated by the battery to be stored in the coolant. The temperature of the coolant becomes higher and higher as it flows in the cold plate. Therefore, the battery cells at the outlet of the liquid cold plate are usually much higher in temperature than those at the inlet of the liquid cold plate, resulting in a large temperature difference in the battery cells, which affects the service life of the battery cells. As the charging time requirements are significantly shortened, the charging current of the battery is getting larger and larger, and the heat generation of the battery is significantly increased. In order to maintain the battery working within the appropriate temperature range, the existing single-sided cooling liquid cooling system design is difficult to meet the required cooling capacity. Utility Model Content

[0004] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a battery pack and a cooling system to improve the problem that the battery cells at the outlet of the liquid cooling plate of the existing cooling system are usually much hotter than the temperature at the inlet of the liquid cooling plate, resulting in a large temperature difference in the battery cells, affecting the service life of the battery cells, and the existing single-sided cooling liquid cooling system design is difficult to meet the required cooling capacity.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a battery pack, comprising:

[0006] A battery cell stack, the battery cell stack comprising a plurality of battery cells stacked on each other;

[0007] A cold plate, the cold plate comprising a first cold plate and a second cold plate, the first cold plate and the second cold plate being respectively arranged on the top surface and the bottom surface of the battery cell stack;

[0008] At least one of the first cold plate and the second cold plate includes a first sub-cold plate and a second sub-cold plate, the first sub-cold plate and the second sub-cold plate are stacked in the thickness direction of the cold plate, a liquid cooling channel is provided in the first sub-cold plate, a direct cooling channel is provided in the second sub-cold plate, a coolant flows in the liquid cooling channel, and a refrigerant flows in the direct cooling channel, wherein the first sub-cold plate is in contact with the battery cell stack.

[0009] In one embodiment of the present invention, both the first cold plate and the second cold plate include the first sub-cold plate and the second sub-cold plate.

[0010] In one embodiment of the present invention, the first cold plate and the second cold plate further include a liquid cooling inlet, a liquid cooling outlet, a direct cooling inlet and a direct cooling outlet, the liquid cooling inlet and the liquid cooling outlet are connected to the liquid cooling channel, and the direct cooling inlet and the direct cooling outlet are connected to the direct cooling channel.

[0011] In one embodiment of the present invention, the liquid cooling channel in the first cold plate and the liquid cooling channel in the second cold plate are connected in parallel, and the direct cooling channel in the first cold plate and the direct cooling channel in the second cold plate are connected in parallel.

[0012] In one embodiment of the present invention, a fluid inlet and outlet device is further included, wherein the fluid inlet and outlet device is installed on one side of the cold plate, and the fluid inlet and outlet device is provided with a first liquid cooling interface, a second liquid cooling interface, a first direct cooling interface, and a second direct cooling interface.

[0013] The first liquid cooling interface is connected to the liquid cooling inlet in the first cold plate and the liquid cooling inlet in the second cold plate through a first confluence pipeline;

[0014] The second liquid cooling interface is connected to the liquid cooling outlet in the first cold plate and the liquid cooling outlet in the second cold plate through a second confluence pipeline;

[0015] The first direct cooling interface is connected to the direct cooling inlet in the first cold plate and the direct cooling inlet in the second cold plate through a third confluence pipeline;

[0016] The second direct cooling interface is connected to the direct cooling outlet in the first cold plate and the direct cooling outlet in the second cold plate through a fourth confluence pipeline.

[0017] In one embodiment of the present invention, the liquid cooling channel includes a plurality of first sub-channels, and the plurality of first sub-channels are connected in series and / or in parallel with each other.

[0018] In one embodiment of the present invention, the direct cooling channel includes a plurality of second sub-channels, and the plurality of second sub-channels are connected in series and / or in parallel with each other.

[0019] In one embodiment of the present invention, the first sub-channel in the liquid-cooling channel and the second sub-channel in the direct-cooling channel extend in the same direction.

[0020] In an embodiment of the present invention, each of the first cold plate and the second cold plate includes two first sub-cold plates and one second sub-cold plate, and the second sub-cold plate is located between the two first sub-cold plates.

[0021] In one embodiment of the present invention, a box frame is further included, the first cold plate and the second cold plate are arranged on the top and bottom of the box frame, and are fixedly connected to the box frame to form an accommodating space, and the battery cell stack is located in the accommodating space.

[0022] The utility model also proposes a cooling system, characterized in that it includes a battery cooling system and an air-conditioning cooling system, the battery cooling system includes a battery pack as described in any one of the above embodiments, the second sub-cold plates in the battery pack are all connected to the air-conditioning cooling system, and the first sub-cold plates in the battery pack are all connected to the battery cooling system.

[0023] The utility model proposes a battery pack and a cooling system, which provide cold plates on the top and bottom surfaces of a battery cell stack, and connect the cold plates on the top and bottom surfaces in parallel, thereby solving the problem of low refrigeration efficiency and improving the cooling effect on the battery to ensure efficient thermal management, and also reducing the temperature difference in the height direction of the battery cells.

[0024] The utility model proposes a battery pack and a cooling system. The cold plate in the battery pack adopts a double-layer cold plate including at least a first sub-cold plate and a second sub-cold plate stacked together. A coolant passes through the cold plate close to one side of the battery cell, and a refrigerant passes through the other cold plate, so that the refrigerant and the coolant can directly exchange heat without using a plate heat exchanger, which greatly reduces the cost of the battery pack liquid cooling system and combines the dual advantages of direct cooling and liquid cooling. However, the problems of uniform temperature difference in the direct cooling solution, complex control of the thermal management system and low two-stage heat exchange efficiency of the liquid cooling solution are avoided; and the refrigerant flows directly in the liquid cooling plate, which reduces pipeline connections and further reduces costs and noise.

[0025] The utility model proposes a cold plate and a cooling system, in which a second cold plate through which a refrigerant circulates is arranged on the outside of a battery pack, which can effectively prevent condensed water from being generated inside the battery pack, thereby avoiding safety hazards and improving its safety. In addition, in a high temperature environment, the heat dissipation of the direct cooling plate to the environment can be weakened, further improving the heat exchange efficiency.

[0026] The utility model proposes a cold plate and a cooling system, which adopts a double-layer cold plate design, wherein the second sub-cold plate in the cold plate is connected to the air-conditioning cooling system, and the first sub-cold plate in the cold plate is connected to the battery cooling system, so that the battery cooling system and the air-conditioning cooling system are still two independent systems, and the two systems can be controlled separately, so the control strategy is relatively simple and has strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 The figure is a schematic diagram of the structure of a battery pack in one embodiment of the utility model.

[0029] Figure 2 The figure is a schematic diagram of the side structure of a battery pack in one embodiment of the utility model.

[0030] Figure 3 This is a schematic diagram of the structure of the cold plate and the battery cell installation in one embodiment of the utility model.

[0031] Figure 4 This is a schematic structural diagram of the installation of the second cold plate and the battery cell in one embodiment of the utility model.

[0032] Figure 5 The figure is a schematic cross-sectional structure diagram of a battery pack in one embodiment of the present invention.

[0033] Figure 6 The utility model is a schematic structural diagram of a first cold plate and a second cold plate in one embodiment.

[0034] Figure 7 The figure is a schematic structural diagram of a fluid inlet and outlet device in one embodiment of the utility model.

[0035] Figure 8 This is a schematic diagram of a first cold plate and a second cold plate connected in parallel in one embodiment of the utility model.

[0036] Fig. 9 This is a front view of a first cold plate and a second cold plate connected in parallel in one embodiment of the utility model.

[0037] Fig.10 This is a schematic diagram of an explosion at a location where a first cold plate and a second cold plate are connected in parallel in one embodiment of the utility model.

[0038] Fig.11 This is a schematic diagram of the flow channel in the first cold plate in one embodiment of the utility model.

[0039] Fig.12 This is a schematic diagram of a liquid cooling channel and a direct cooling channel in one embodiment of the utility model.

[0040] Fig.13 The figure is a structural block diagram of a cooling system in one embodiment of the present invention.

[0041] Description of labels:

[0042] 100, battery pack; 10, box frame; 20, battery cell stack; 30, cold plate; 31, first cold plate; 32, second cold plate; 311, first sub-cold plate; 312, second sub-cold plate; 301, liquid cooling channel; 302, direct cooling channel; 303, liquid cooling inlet; 304, liquid cooling outlet; 305, direct cooling inlet; 306, direct cooling outlet; 310, fluid inlet and outlet device; 320, first liquid cooling interface; 330, second liquid cooling Interface; 321, first confluence pipeline; 331, second confluence pipeline; 340, first direct cooling interface; 350, second direct cooling interface; 341, third confluence pipeline; 351, fourth confluence pipeline; 3011, first sub-channel; 3012, first confluence channel; 3021, second sub-channel; 3022, second confluence channel; 400, cooling system; 410, expansion valve; 420, condenser; 430, compressor; 440, water pump. DETAILED DESCRIPTION

[0043] The following is an explanation of the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0045] It should be noted that long-term operation of existing batteries in high-temperature environments will lead to intensified side reactions inside the batteries, which will not only affect the service life of the battery cells, but also increase the probability of thermal runaway of the batteries. The decay of battery service life and the risk of thermal runaway greatly affect the user experience of electric vehicles. Therefore, the battery packs equipped with new energy vehicles are generally designed with a cooling system to dissipate the heat accumulated during the use of the battery cells to ensure that the battery operates within an appropriate temperature range.

[0046] For the battery cooling system, the circuit generally includes components such as water pumps, liquid cooling plates, plate heat exchangers, and liquid storage pots. When the cooling system is working, under the action of the water pump, the high-temperature coolant flows out from the outlet of the liquid cooling plate and enters one side of the plate heat exchanger. The low-temperature refrigerant passes through the other side of the plate heat exchanger. After the high-temperature coolant exchanges heat with the low-temperature refrigerant, the temperature is reduced. After flowing out of the plate heat exchanger, it enters the inlet of the liquid cooling plate. The low-temperature coolant in the liquid cooling plate exchanges heat with the battery cell and becomes high-temperature coolant, which flows out of the outlet of the liquid cooling plate. The cycle repeats, thereby taking the heat from the battery pack when it is working. Among them, the plate heat exchanger provides a place for the low-temperature refrigerant and the high-temperature coolant to exchange heat, and it is also a bridge for the battery pack coolant system and the vehicle air conditioning cooling system to connect with each other.

[0047] The existing cooling system using plate heat exchanger has the problem that the low-temperature refrigerant does not directly participate in the heat exchange process of the battery, so it cannot directly take away the heat of the battery when it is working. Instead, it needs to exchange heat between the coolant and the coolant after the heat exchange between the coolant and the battery is completed, and then indirectly take away the heat. This two-stage heat exchange mode causes the heat generated by the battery to be partially stored in the coolant. The temperature of the coolant becomes higher and higher when it flows in the cold plate. Therefore, the battery cell at the outlet of the liquid cold plate is usually much higher than the temperature at the inlet of the liquid cold plate, resulting in a large temperature difference of the battery cell, which affects the service life of the battery cell. In addition, the plate heat exchanger is relatively expensive, and a large number of pipes are required to connect the plate heat exchanger and the cold plate. In order to reduce the heat loss of the coolant in the external pipeline, the surface of these pipes needs to be coated with a large amount of insulation material, which leads to the problem of further cost increase. As the charging time requirement is significantly shortened, the charging current of the battery is getting larger and larger, and the heat generation of the battery is significantly increased. In order to maintain the battery working within a suitable temperature range, the existing single-sided cooling liquid cooling system design is difficult to meet the required cooling capacity.

[0048] To solve the above technical problems, please refer to Figures 1 to 12As shown, the utility model proposes a battery pack 100, which includes a box frame 10, a battery cell stack 20 and a cold plate 30, wherein the cold plate 30 includes a first cold plate 31 and a second cold plate 32, and the first cold plate 31 and the second cold plate 32 are respectively arranged on the top surface and the bottom surface of the battery cell stack 20. Specifically, the first cold plate 31 and the second cold plate 32 are arranged on the top and the bottom of the box frame 10, and are fixedly connected to the box frame 10 to form an accommodating space. The battery cell stack 20 includes a plurality of battery cells stacked on each other, and the battery cell stack 20 is installed in the accommodating space.

[0049] See also Figures 1 to 6 As shown, in this embodiment, at least one of the first cold plate 31 and the second cold plate 32 includes a first sub-cold plate 311 and a second sub-cold plate 312, the first sub-cold plate 311 and the second sub-cold plate 312 are stacked in the thickness direction of the cold plate, a liquid cooling channel 301 is provided in the first sub-cold plate 311, and a direct cooling channel 302 is provided in the second sub-cold plate 312, a coolant flows in the liquid cooling channel 301, and a refrigerant flows in the direct cooling channel 302. The first sub-cold plate 311 is in contact with the battery cell stack 20, and by arranging cold plates on both the top and bottom surfaces of the battery cell stack 20, it not only solves the problem of low cooling efficiency, but also improves the cooling effect on the battery, so as to ensure efficient thermal management effect, and can also reduce the temperature difference in the height direction of the battery cell. It should be noted that, when only one of the first cold plate 31 and the second cold plate 32 is configured to include a first sub-cold plate 311 and a second sub-cold plate 312, the other of the first cold plate 31 and the second cold plate 32 can be designed as a liquid cooling plate, that is, it only includes a liquid cooling channel, and the liquid cooling channel in the liquid cooling plate can be connected in series with the liquid cooling channel 301 in the first sub-cold plate 311.

[0050] Of course, the first cold plate 31 and the second cold plate 32 may both include the first sub-cold plate 311 and the second sub-cold plate 312 . The following embodiments are described by taking the first cold plate 31 and the second cold plate 32 both including the first sub-cold plate 311 and the second sub-cold plate 312 as an example.

[0051] See also Figures 1 to 6As shown, the cold plate in the liquid-cooled battery pack 100 adopts a double-layer cold plate including at least a first sub-cold plate 311 and a second sub-cold plate 312 stacked and arranged. The coolant passes through the first sub-cold plate 311 close to the battery cell side, and the refrigerant passes through the second sub-cold plate 312 away from the battery cell side, so that the refrigerant and the coolant can directly exchange heat without using a plate heat exchanger, which greatly reduces the cost of the battery pack liquid cooling system, and combines the dual advantages of direct cooling and liquid cooling, while avoiding the problems of uniform temperature difference in the direct cooling scheme, complex control of the thermal management system, and low two-stage heat exchange efficiency of the liquid cooling scheme; and the refrigerant flows directly in the liquid cooling plate, reducing the pipeline connection, and further reducing the cost and noise. In this embodiment, the coolant is a water-ethylene glycol coolant, and the refrigerant is Freon, but it can be understood that the coolant can also be set to other different coolants, and the refrigerant can also be set to other different refrigerant media, as long as the purpose of this application can be achieved.

[0052] It can also be understood that the existing cold plate design may have a too low temperature on the refrigerant side, which may lead to condensation, which may affect the maintenance of the dry environment inside the battery pack 100. In this embodiment, the first cold plate 31 and the second cold plate 32 are respectively arranged on the top and bottom surfaces of the battery cell stack 20, wherein the first sub-cold plate 311 of the first cold plate 31 and the second cold plate 32, which is a liquid-cooled plate, is in contact with the battery cell stack 20, and the second sub-cold plate 312, which is a direct-cooled plate, is located on the side away from the battery cell stack 20, that is, the second sub-cold plate 312 through which the refrigerant circulates is located outside the battery pack 100, which can effectively avoid the generation of condensed water inside the battery pack 100, thereby avoiding safety hazards and improving its safety. In addition, in a high temperature environment, the heat dissipation of the direct-cooled plate to the environment can be weakened, further improving the heat exchange efficiency.

[0053] See also Figure 7As shown, in this embodiment, the first cold plate 31 and the second cold plate 32 further include a liquid cooling inlet 303, a liquid cooling outlet 304, a direct cooling inlet 305 and a direct cooling outlet 306, the liquid cooling inlet 303 and the liquid cooling outlet 304 are connected to the liquid cooling channel 301, and the direct cooling inlet 305 and the direct cooling outlet 306 are connected to the direct cooling channel 302. Take the first cold plate 31 as an example for explanation: a fluid inlet and outlet device 310 is provided on one side of the first cold plate 31, the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305 and the direct cooling outlet 306 are integrated and installed on the fluid inlet and outlet device 310, and the liquid cooling inlet 303 and the liquid cooling outlet 304 are connected to the liquid cooling channel 301, and the direct cooling inlet 305 and the direct cooling outlet 306 are connected to the direct cooling channel 302. For example, the fluid inlet and outlet devices 310 are provided on the same side of the first cold plate 31 and the second cold plate 32, so that the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305, and the direct cooling outlet 306 of the first cold plate 31 can be connected to the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305, and the direct cooling outlet 306 of the second cold plate 32 through the confluence pipeline, thereby connecting the first cold plate 31 and the second cold plate 32 together.

[0054] See also Figures 7 to 10 As shown, in this embodiment, the first cold plate 31 and the second cold plate 32 are connected in parallel, specifically, the liquid cooling channel 301 in the first cold plate 31 and the liquid cooling channel 301 in the second cold plate 32 are connected in parallel, and the direct cooling channel 302 in the first cold plate 31 and the direct cooling channel 302 in the second cold plate 32 are connected in parallel. The cold plate on the top surface of the battery cell stack 20 and the cold plate on the bottom surface are connected in parallel, which not only solves the problem of low cooling efficiency, but also improves the cooling effect on the battery to ensure efficient thermal management effect, and can also reduce the temperature difference in the height direction of the battery cell.

[0055] See also Figures 7 to 10 As shown, in this embodiment, the battery pack 100 also includes a first liquid cooling interface 320 and a second liquid cooling interface 330. The first liquid cooling interface 320 is connected to the liquid cooling inlet 303 in the first cold plate 31 and the liquid cooling inlet 303 in the second cold plate 32 through a first bus pipe 321; the second liquid cooling interface 330 is connected to the liquid cooling outlet 304 in the first cold plate 31 and the liquid cooling outlet 304 in the second cold plate 32 through a second bus pipe 331. That is, the cooling liquid flows in from the first liquid cooling interface 320, flows through the first confluence pipe 321 to the liquid cooling inlets 303 on the first cold plate 31 and the second cold plate 32 respectively, and flows into the liquid cooling channels 301 in the first cold plate 31 and the second cold plate 32, and then flows through the liquid cooling outlets 304 on the first cold plate 31 and the second cold plate 32, and flows out from the second liquid cooling interface 330 after confluence through the second confluence pipe 331, so as to realize the parallel connection of the liquid cooling channels 301 in the first cold plate 31 and the second cold plate 32.

[0056] See also Figures 7 to 10 As shown, in this embodiment, the battery pack 100 also includes a first direct cooling interface 340 and a second direct cooling interface 350. The first direct cooling interface 340 is connected to the direct cooling inlet 305 in the first cold plate 31 and the direct cooling inlet 305 in the second cold plate 32 through a third bus pipe 341; the second direct cooling interface 350 is connected to the direct cooling outlet 306 in the first cold plate 31 and the direct cooling outlet 306 in the second cold plate 32 through a fourth bus pipe 351. That is, the refrigerant flows in from the first direct cooling interface 340, flows to the direct cooling inlets 305 on the first cold plate 31 and the second cold plate 32 respectively through the third confluence pipe 341, and flows into the direct cooling flow channels 302 in the first cold plate 31 and the second cold plate 32, and then passes through the direct cooling outlets 306 on the first cold plate 31 and the second cold plate 32, and flows out from the second direct cooling interface 350 after confluence through the fourth confluence pipe 351, so as to realize the parallel connection of the direct cooling flow channels 302 in the first cold plate 31 and the second cold plate 32.

[0057] See also Figures 7 to 10 As shown, in this embodiment, the liquid cooling channel 301 includes a plurality of first sub-channels 3011, and the plurality of first sub-channels 3011 can be set to be a mixed series and parallel setting, for example, some of the sub-channels in the plurality of first sub-channels 3011 are connected in parallel to form a parallel channel module, and the plurality of parallel channel modules are connected in series. At this time, the two first sub-channels 3011 located at the head and tail of each parallel channel module are respectively connected to two different first confluence channels 3012, when the first confluence channel 3012 is connected to the liquid cooling inlet 303, the coolant flows from the liquid cooling inlet 303 into the first confluence channel 3012, and flows into the first sub-channels 3011 in different parallel channel modules through the first confluence channel 3012, or when the first confluence channel 3012 is connected to the liquid cooling outlet 304, the coolant flows from the first sub-channels 3011 in different parallel channel modules into the first confluence channel 3012, and flows out through the liquid cooling outlet 304.

[0058] It is understandable that the multiple first sub-channels 3011 can also be arranged to be connected in series with each other. For example, the multiple first sub-channels 3011 are connected in series, wherein the two first sub-channels 3011 located at the head and the tail are respectively connected to the liquid cooling inlet 303 and the liquid cooling outlet 304.

[0059] It can also be understood that the plurality of first sub-channels 3011 can also be arranged to be connected in parallel with each other. In this case, the liquid-cooling channel 301 further includes a first confluence channel 3012, and the plurality of first sub-channels 3011 are connected to the first confluence channel 3012, and the first confluence channel 3012 is connected to the liquid-cooling inlet 303 or the liquid-cooling outlet 304. That is, when the first confluence channel 3012 is connected to the liquid-cooling inlet 303, the cooling liquid flows from the liquid-cooling inlet 303 into the confluence channel, and flows into different first sub-channels 3011 through the first confluence channel 3012, or when the first confluence channel 3012 is connected to the liquid-cooling outlet 304, the cooling liquid flows from the plurality of first sub-channels 3011 into the first confluence channel 3012, and flows out through the liquid-cooling outlet 304.

[0060] See also Figures 7 to 10 As shown, in this embodiment, the direct cooling channel 302 includes a plurality of second sub-channels 3021, and the plurality of second sub-channels 3021 can be set to a mixed series and parallel setting. For example, some of the sub-channels in the plurality of second sub-channels 3021 are connected in parallel to form a parallel channel module, and the plurality of parallel channel modules are connected in series with each other. At this time, the two second sub-channels 3021 located at the head and tail of each parallel channel module are respectively connected to two different second confluence channels 3022, and when the second confluence channel 3022 is connected to the direct cooling inlet 305, the refrigerant flows from the direct cooling inlet 305 into the confluence channel, and flows into the second sub-channels 3021 in different parallel channel modules through the second confluence channel 3022, or when the second confluence channel 3022 is connected to the direct cooling outlet 306, the refrigerant flows from the second sub-channels 3021 in different parallel channel modules into the second confluence channel 3022, and flows out through the direct cooling outlet 306.

[0061] It is understandable that the multiple second sub-channels 3021 can also be arranged to be connected in series with each other. For example, the multiple second sub-channels 3021 are connected in series, wherein the two second sub-channels 3021 located at the head and the tail are respectively connected to the direct cooling inlet 305 and the direct cooling outlet 306.

[0062] It can also be understood that the plurality of second sub-channels 3021 can also be arranged to be connected in parallel with each other. At this time, the direct cooling channel 302 also includes a second confluence channel 3022, and the plurality of second sub-channels 3021 are connected to the second confluence channel 3022, and the second confluence channel 3022 is connected to the direct cooling inlet 305 or the direct cooling outlet 306. That is, when the second confluence channel 3022 is connected to the direct cooling inlet 305, the refrigerant flows into the second confluence channel 3022 from the direct cooling inlet 305, and flows into different second sub-channels 3021 through the second confluence channel 3022, or when the second confluence channel 3022 is connected to the direct cooling outlet 306, the refrigerant flows into the second confluence channel 3022 from the plurality of second sub-channels 3021, and flows out through the direct cooling outlet 306.

[0063] See also Fig.11 and Fig.12 As shown, in this embodiment, the first sub-channel 3011 in the liquid-cooling channel 301 and the second sub-channel 3021 in the direct cooling channel 302 extend in the same direction, for example, the first sub-channel 3011 and the second sub-channel 3021 are arranged in parallel, that is, the flow direction of the circulating refrigerant is consistent with the flow direction of the circulating coolant, so as to improve the heat exchange efficiency between the two. It should be noted that the flow direction of the coolant in the liquid-cooling channel 301 and the flow direction of the refrigerant in the direct cooling channel 302 can be the same or opposite.

[0064] See also Figures 7 to 12 As shown, in this embodiment, the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305 and the direct cooling outlet 306 are integrated and installed on the fluid inlet and outlet device 310, that is, the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305 and the direct cooling outlet 306 are located on the same side of the cold plate, so as to facilitate the first cold plate 31 and the second cold plate 32 to be connected in parallel through the first liquid cooling interface 320, the second liquid cooling interface 330, the first direct cooling interface 340, the second direct cooling interface 350 and the corresponding confluence pipeline to reduce the length of the pipeline, which is convenient for the assembly of the battery pack 100 and can reduce the cost. Of course, the liquid cooling inlet 303, the liquid cooling outlet 304, the direct cooling inlet 305 and the direct cooling outlet 306 can also be set on different sides of the cold plate, which can be set according to needs.

[0065] In some other embodiments, the first cold plate 31 and the second cold plate 32 can also be configured to each include two first sub-cold plates 311 and one second sub-cold plate 312, the second sub-cold plate 312 is located between the two first sub-cold plates 311, and the two first sub-cold plates 311 can be connected in parallel or in series with each other. At this time, the direct cooling is located between the liquid cooling on both sides, which can avoid the low refrigerant temperature causing the nearby air to condense and form water droplets, thereby avoiding safety hazards and improving its safety. In a high temperature environment, the heat dissipation of the direct cooling plate to the environment can be weakened, further improving the heat exchange efficiency.

[0066] See also Figure 5 As shown, in the present embodiment, the first cold plate 31 and the second cold plate 32 can be designed to have multiple layers of liquid cooling channels 301 and direct cooling channels 302 in the integrated plate along its thickness direction; of course, in some other embodiments, the first cold plate 31 and the second cold plate 32 can also be configured to be formed by stacking multiple plates, for example, a liquid cooling plate provided with a liquid cooling channel 301 and a direct cooling plate provided with a direct cooling channel 302 can be stacked along its thickness direction.

[0067] See also Figures 1 to 13As shown, the utility model also proposes a cooling system, the cooling system 400 includes a battery cooling system and an air-conditioning cooling system, the battery cooling system includes the battery pack 100 as described in the above embodiment, the second sub-cold plate 312 in the battery pack 100 is connected to the air-conditioning cooling system, the first sub-cold plate 311 in the battery pack 100 is connected to the battery cooling system, the first direct cooling interface 340 is connected to the outlet of the condenser 420 through the expansion valve 410, the second direct cooling interface 350 is connected to the inlet of the condenser 420 through the compressor 430, and the first liquid cooling interface 320 and the second liquid cooling interface 330 are respectively connected to the outlet and inlet of the water pump 440. It can be understood that due to the presence of the cold plate 30 in the battery pack 100, the refrigerant and the coolant can directly exchange heat without using a plate heat exchanger, which greatly reduces the cost of the battery pack liquid cooling system and combines the dual advantages of direct cooling and liquid cooling. However, it avoids the problems of uniform temperature difference in the direct cooling solution, complex control of the thermal management system, and low two-stage heat exchange efficiency of the liquid cooling solution. The refrigerant flows directly in the liquid cooling plate, reducing pipeline connections, further reducing costs and noise. In addition, the battery cooling system and the air-conditioning cooling system remain two independent systems, and the two systems can be controlled separately. Therefore, the control strategy is relatively simple and has strong compatibility.

[0068] It should also be noted that when the cold plate 30 is installed in the battery pack, the density of the first sub-channels 3011 and the second sub-channels 3021 in the liquid cooling channel 301 of each layer and the direct cooling channel 302 can be set according to the arrangement of the battery cells in the battery pack and the arrangement of the heat generated by the battery cells. For example, the closer the multiple first sub-channels 3011 and the multiple second sub-channels 3021 are to the middle of the cold plate, the greater their density is, so that the cooling effect and cooling efficiency can be better improved.

[0069] The utility model proposes a battery pack and a cooling system, which provide cold plates on the top and bottom surfaces of a battery cell stack, and connect the cold plates on the top and bottom surfaces in parallel, thereby solving the problem of low refrigeration efficiency and improving the cooling effect on the battery to ensure efficient thermal management, and also reducing the temperature difference in the height direction of the battery cells.

[0070] The utility model proposes a battery pack and a cooling system. The cold plate in the battery pack adopts a double-layer cold plate including at least a first sub-cold plate and a second sub-cold plate stacked together. A coolant passes through the cold plate close to one side of the battery cell, and a refrigerant passes through the other cold plate, so that the refrigerant and the coolant can directly exchange heat without using a plate heat exchanger, which greatly reduces the cost of the battery pack liquid cooling system and combines the dual advantages of direct cooling and liquid cooling. However, the problems of uniform temperature difference in the direct cooling solution, complex control of the thermal management system and low two-stage heat exchange efficiency of the liquid cooling solution are avoided; and the refrigerant flows directly in the liquid cooling plate, which reduces pipeline connections and further reduces costs and noise.

[0071] The utility model proposes a cold plate and a cooling system, in which a second cold plate through which a refrigerant circulates is arranged on the outside of a battery pack, which can effectively prevent condensed water from being generated inside the battery pack, thereby avoiding safety hazards and improving its safety. In addition, in a high temperature environment, the heat dissipation of the direct cooling plate to the environment can be weakened, further improving the heat exchange efficiency.

[0072] The utility model proposes a cold plate and a cooling system, which adopts a double-layer cold plate design, wherein the second sub-cold plate in the cold plate is connected to the air-conditioning cooling system, and the first sub-cold plate in the cold plate is connected to the battery cooling system, so that the battery cooling system and the air-conditioning cooling system are still two independent systems, and the two systems can be controlled separately, so the control strategy is relatively simple and has strong compatibility.

[0073] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the concept of the utility model, such as a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

[0074] Except for the technical features in the specification, the other technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present utility model, the other technical features will not be described in detail here.

Claims

1. A battery pack, characterized in that: include: A battery cell stack, the battery cell stack comprising a plurality of battery cells stacked on each other; A cold plate, the cold plate comprising a first cold plate and a second cold plate, the first cold plate and the second cold plate being respectively arranged on the top surface and the bottom surface of the battery cell stack; At least one of the first cold plate and the second cold plate includes a first sub-cold plate and a second sub-cold plate, the first sub-cold plate and the second sub-cold plate are stacked in the thickness direction of the cold plate, a liquid cooling channel is provided in the first sub-cold plate, a direct cooling channel is provided in the second sub-cold plate, a coolant flows in the liquid cooling channel, and a refrigerant flows in the direct cooling channel, wherein the first sub-cold plate is in contact with the battery cell stack.

2. The battery pack according to claim 1, characterized in that: The first cold plate and the second cold plate each include the first sub-cold plate and the second sub-cold plate.

3. The battery pack according to claim 2, characterized in that: The first cold plate and the second cold plate further include a liquid cooling inlet, a liquid cooling outlet, a direct cooling inlet and a direct cooling outlet, the liquid cooling inlet and the liquid cooling outlet are connected to the liquid cooling channel, and the direct cooling inlet and the direct cooling outlet are connected to the direct cooling channel.

4. The battery pack according to claim 3, characterized in that: The liquid cooling channel in the first cold plate and the liquid cooling channel in the second cold plate are connected in parallel, and the direct cooling channel in the first cold plate and the direct cooling channel in the second cold plate are connected in parallel.

5. The battery pack according to claim 4, characterized in that: It also includes a fluid inlet and outlet device, which is installed on one side of the cold plate, and is provided with a first liquid cooling interface, a second liquid cooling interface, a first direct cooling interface, and a second direct cooling interface. The first liquid cooling interface is connected to the liquid cooling inlet in the first cold plate and the liquid cooling inlet in the second cold plate through a first confluence pipeline; The second liquid cooling interface is connected to the liquid cooling outlet in the first cold plate and the liquid cooling outlet in the second cold plate through a second confluence pipeline; The first direct cooling interface is connected to the direct cooling inlet in the first cold plate and the direct cooling inlet in the second cold plate through a third confluence pipeline; The second direct cooling interface is connected to the direct cooling outlet in the first cold plate and the direct cooling outlet in the second cold plate through a fourth confluence pipeline.

6. The battery pack according to claim 1, characterized in that: The liquid cooling channel includes a plurality of first sub-channels, and the plurality of first sub-channels are connected in series and / or in parallel with each other.

7. The battery pack according to claim 1, characterized in that: The direct cooling channel includes a plurality of second sub-channels, and the plurality of second sub-channels are connected in series and / or in parallel with each other.

8. The battery pack according to claim 1, characterized in that: The first sub-channel in the liquid-cooling channel and the second sub-channel in the direct-cooling channel extend in the same direction.

9. The battery pack according to claim 1, characterized in that: At least one of the first cold plate and the second cold plate includes two first sub-cold plates and one second sub-cold plate, and the second sub-cold plate is located between the two first sub-cold plates.

10. The battery pack according to claim 1, characterized in that: It also includes a box frame, the first cold plate and the second cold plate are arranged on the top and bottom of the box frame, and are fixedly connected to the box frame to form an accommodating space, and the battery cell stack is located in the accommodating space.

11. A cooling system, characterized in that: It comprises a battery cooling system and an air conditioning cooling system, the battery cooling system comprises a battery pack as described in any one of claims 1 to 10, the second sub-cold plates in the battery pack are all connected to the air conditioning cooling system, and the first sub-cold plates in the battery pack are all connected to the battery cooling system.

Images