CN213366658U

CN213366658U - Battery pack

Info

Publication number: CN213366658U
Application number: CN202021132858.0U
Authority: CN
Inventors: 李军林; 李磊; 黄一波; 吴斌; 杨政杰
Original assignee: Evergrande New Energy Technology Shenzhen Co Ltd; Shanghai Cenat New Energy Co Ltd
Current assignee: Evergrande New Energy Technology Shenzhen Co Ltd; Shanghai Cenat New Energy Co Ltd
Priority date: 2020-06-17
Filing date: 2020-06-17
Publication date: 2021-06-04
Anticipated expiration: 2030-06-17

Abstract

The utility model relates to a battery pack cooling technical field, more specifically relates to a battery pack which comprises a box body and a cover plate, wherein the box body comprises a flow channel, the flow channel comprises a main flow channel, a second-stage flow channel connected in parallel and a return water flow channel; the main flow channels are respectively communicated with the second-stage flow channels which are connected in parallel, and the second-stage flow channels which are connected in parallel are respectively communicated with the return water flow channels; the parallel second-stage flow channels are arranged on two sides of the return water flow channel, the main flow channel is provided with a liquid inlet interface, and the return water flow channel is provided with a liquid outlet interface. The utility model integrates the flow channel into the box body of the battery pack, saves the space of the battery pack and improves the energy density of the battery pack; because the closed flow channel is adopted, the traditional pipeline structure is abandoned, the problem of liquid leakage risk caused by the traditional pipeline joint is avoided, and the safety is improved; the runner is simple and reasonable in arrangement, and the consistency of heat dissipation capacity is guaranteed.

Description

Battery pack

Technical Field

The utility model relates to a battery package cooling technology field, more specifically relates to a battery package.

Background

With the wider and more-wider application of power batteries and the trend, the thermal safety problem of the power batteries becomes an industrial technical hotspot and a technical problem. The technical scheme of cooling the battery pack at present mainly is that a battery pack cooling system is arranged outside a battery module in the battery pack. The battery pack cooling system occupies a large internal space of the battery pack, and influences the energy density of the whole battery pack. In addition, the existing battery pack cooling system comprises a pipeline joint part, the structure is complex, and the risk problem of leakage of cooling liquid exists. For example, CN109494427A discloses a liquid cooling system for a power battery pack, which includes a frame body and a heat dissipation assembly, wherein the heat dissipation assembly is embedded in the frame body, the heat dissipation assembly includes a plurality of liquid cooling plates and a plurality of flow channels disposed on the liquid cooling plates, the flow channels are disposed in combination of a serpentine type and a direct current type, and the flow channels are disposed in combination of a serial connection and a parallel connection. The liquid cooling system has a complex structure and has the problem of leakage of cooling liquid; in addition, the energy density of the battery pack is affected because the battery pack occupies a large internal space.

SUMMERY OF THE UTILITY MODEL

The utility model discloses an it is big to overcome among the prior art battery package cooling system and occupy battery package inner space, and problem and battery package cooling system structure that influence battery package energy density are complicated, have the problem that the risk was revealed to the coolant liquid, provide a battery package.

In order to solve the technical problem, the utility model discloses a technical scheme is:

the battery pack comprises a box body and a cover plate, wherein the box body comprises a flow channel, and the flow channel comprises a main flow channel, a second-stage flow channel and a return water flow channel which are connected in parallel; the main flow channels are respectively communicated with the second-stage flow channels which are connected in parallel, and the second-stage flow channels which are connected in parallel are respectively communicated with the return water flow channels; the parallel second-stage flow channels are arranged on two sides of the return water flow channel, the main flow channel is provided with a liquid inlet interface, and the return water flow channel is provided with a liquid outlet interface. In the application, the flow channel is optimally integrated on the box body of the battery pack, so that the space of the battery pack is saved, and the energy density of the battery pack is improved; because the closed flow channel is adopted, the traditional pipeline structure is abandoned, the problem of liquid leakage risk caused by the traditional pipeline joint is avoided, and the safety is improved; the flow channel arrangement design ensures the consistency of the heat dissipation capacity.

In the technical scheme, the cooling liquid enters the main flow channel through the liquid inlet interface, the main flow channel is divided into at least two groups of second-stage flow channels which are connected in parallel, and then the second-stage flow channels converge into a group of water return flow channels. In addition, two groups of second-stage runners connected in parallel are arranged on two sides of the water return runner, and the water is fed from the second-stage runners connected in parallel on two sides and discharged from the water return runner in the middle, so that the uniform flow distribution is ensured.

Preferably, the structure of the flow channel adopts a series-parallel structure which is connected in parallel in a grading way and then converged into one path in series. Preferably, the structure of the flow channel adopts a series-parallel structure that two paths are firstly connected in parallel, then four paths are connected in parallel and then converged into one path to be connected in series. The flow channels connected in parallel in a grading way are basically designed symmetrically, so that the flow distribution is further ensured to be uniform.

Preferably, the second-stage flow channels connected in parallel are four-way parallel, each second-stage flow channel comprises a plurality of second-stage main flow channels communicated with the main flow channel and at least two groups of second-stage branch flow channels, one ends of the second-stage branch flow channels are communicated with the second-stage main flow channels, and the other ends of the second-stage branch flow channels are communicated with the water return flow channels. In the technical scheme, the second-stage flow channels connected in parallel comprise at least two groups of second-stage branch flow channels, and the cooling liquid in the main flow channel can be further dispersed into the second-stage branch flow channels, so that the bottom of each module can be further ensured to be fully distributed with the flow channels, and the consistency of the heat dissipation capacity of each module is ensured.

Preferably, the second-stage branch flow passages are provided with three groups, and the three groups of second-stage branch flow passages are arranged back and forth; the other end of the second-stage branch flow passage positioned in the middle is respectively communicated with the second-stage branch flow passages on the two sides and then communicated with the water return flow passage. In the technical scheme, three groups of second-stage branch flow passages are arranged, then the three groups of second-stage branch flow passages are combined into two groups and communicated with the backwater flow passage, and the second-stage branch flow passages adopt a three-in two-out backflow structure, so that the problems of reduced Reynolds coefficient and heat exchange capacity due to reduced flow are solved, and the temperature uniformity is improved.

Preferably, the flow passage further comprises a first stage flow passage for communicating the main flow passage with a second stage flow passage connected in parallel. In this technical scheme, parallelly connected second grade runner is linked together through first grade runner and sprue, and the purpose that sets up like this is in order to shunt the coolant liquid from the sprue, guarantees that the coolant liquid dispersion is even, ensures that module contact surface heat-sinking capability is unanimous.

Preferably, the first-stage flow channel comprises a first-stage main flow channel communicated with the main flow channel, a plurality of first-stage branch flow channels communicated with the first-stage main flow channel, and a first-stage return flow channel for communicating the plurality of first-stage branch flow channels, and the first-stage return flow channel is communicated with the second-stage flow channels connected in parallel. In this technical scheme, the first order runner includes a plurality of first grade branch runners, and first grade branch runner can be shunted the coolant liquid from the sprue, guarantees that the coolant liquid dispersion is even, ensures that the module contact surface heat-sinking capability is unanimous.

Preferably, the first-stage main flow channel, the first-stage branch flow channel and the first-stage return water flow channel are arranged in a parallelogram shape. Because first-level branch runner is less, first-level sprue and first-level return water runner parallel arrangement can guarantee the uniformity of coolant liquid velocity of flow among all first-level branch runners like this, because the flow is even, just can guarantee that the heat transfer capacity of single module is unanimous, if the heat transfer capacity is inconsistent, can lead to the heat dissipation inequality of single module, cause the very big problem of the each partial difference in temperature of module.

Preferably, the first-stage runners and the parallel second-stage runners are arranged in a direction perpendicular to the arrangement direction of the battery cells, and the plurality of first-stage runners and the parallel second-stage runners are symmetrically arranged on two sides of the water return runner respectively. The first-stage flow channel and the parallel second-stage flow channel are perpendicular to the arrangement direction of the battery cells, so that the temperature uniformity of the first-stage flow channel and the parallel second-stage flow channel is better.

Preferably, the backwater flow channel comprises a first main backwater flow channel communicated with the second-stage flow channels connected in parallel, at least two groups of first-stage branch backwater flow channels communicated with the first main backwater flow channel and a plurality of second-stage branch backwater flow channels communicated with the first-stage branch backwater flow channels; the second-stage branch backwater flow passage is communicated with the liquid outlet interface.

Further, based on the utility model discloses a runner groove structural feature can form through milling, sculpture, casting mode, need not set up the pipeline and connects the part. The technical scheme has simple closed flow channel, and solves the problem that the traditional battery pack cooling system comprises a pipeline joint part and a complex structure, and the existing cooling liquid leaks.

Preferably, the liquid outlet port crosses the flow passage without contacting with the inside of the flow passage, and the cross section of the flow passage is rectangular or semicircular. In the technical scheme, the design of a flow channel crossing scheme that the outlet section of the flow channel is vertically upwards firstly and then horizontally flows out to cross the flow channel of the inlet section is adopted, the flow channel is prevented from adopting an external shunt pipeline at the liquid inlet interface section, and the design is simplified.

Preferably, the flow channel is formed by closing the flow channel groove at the bottom of the box body and the bottom plate. The box body comprises a runner groove, the runner groove is formed in the bottom of the box body, the box body further comprises a bottom plate, and the bottom plate and the runner groove are sealed to form a runner. The flow channel is integrated at the bottom of the box body by adopting the existing mode in the field or the flow channel groove can be directly processed at the bottom of the box body, thus being very simple and easy to implement. Specifically, the box body and the cover plate cover to form an accommodating space for accommodating the battery module; the whole flow channel is T-shaped, and adopts a two-path parallel connection structure and a four-path parallel connection structure and is distributed in parallel according to the position of the battery module in a matching way; the first-stage flow channel and the parallel second-stage flow channel of the flow channel are arranged in a direction perpendicular to the arrangement direction of the battery cores in the battery module. The structure ensures that the bottom of each module is fully distributed with the flow channel, and ensures the consistency of the heat dissipation capacity of each module. The flow channel is basically designed symmetrically, and the flow distribution is ensured to be uniform by combining the structural design of water inlet at two sides and water outlet at the middle. Based on the utility model discloses, the runner of box body bottom is located to the battery package, and its preceding tip subchannel has adopted the reposition of redundant personnel floor structure, guarantees that the coolant liquid dispersion is even, ensures that module contact surface heat-sinking capability is unanimous. The partial flow channel adopts a three-in two-out backflow structure, so that the conditions that the Reynolds number is reduced and the heat exchange capacity is reduced due to the reduction of flow are avoided, and the temperature uniformity is improved. In addition, the liquid inlet interface and the liquid outlet interface are arranged on the same side, and the liquid inlet interface and the liquid outlet interface need to be communicated with an external pipeline, so that the purposes of saving the length of the external pipeline and reducing the space occupied by the external pipeline can be achieved. The liquid outlet interface crosses the flow channel and is not contacted with the inside of the flow channel, specifically, the liquid outlet interface adopts a flow channel cross scheme design that the liquid outlet interface firstly vertically faces upwards and then horizontally crosses the liquid inlet interface section, thereby avoiding the inlet interface section from adopting an external shunt pipeline and simplifying the design.

Preferably, can set up boss structure on the box body, boss structure is used for the installation of bottom plate, and mutually adaptation ground sets up the groove structure with boss structure looks adaptation on the bottom plate, for the convenience of mounting plate provides the location to make the leakproofness that can guarantee the runner better. Of course, a groove can be arranged on the box body, and a boss structure matched with the groove is arranged on the bottom plate.

Compared with the prior art, the beneficial effects are:

the utility model discloses compare with current battery package cooling system, because the direct integration of runner is at the box body of battery package, realized no pipeline structure, reduced the space demand, saved the space of battery package, improved battery package energy density. Furthermore, because a closed flow channel is adopted instead of a pipeline structure, the flow channel is simple, the problem of liquid leakage risk caused by the traditional pipeline joint is avoided, and the safety is improved. The utility model discloses a problem of heat transfer ability uniformity has been solved in the design of arranging of runner.

Drawings

Fig. 1 is an exploded view of the battery pack of the present invention;

FIG. 2 is a schematic structural view of a flow channel groove in a battery pack according to the present invention;

fig. 3 is a schematic structural diagram I of a flow channel in a battery pack according to the present invention;

fig. 4 is a schematic structural diagram II of a flow channel in a battery pack according to the present invention;

fig. 5 is a schematic structural diagram III of a flow channel in a battery pack according to the present invention;

FIG. 6 is an enlarged view of detail A of FIG. 5;

in the attached drawing, 1-a box body, 2-a runner groove, 3-a bottom plate, 4-runners, 5-a liquid inlet interface, 6-a liquid outlet interface, 7-a boss structure, 8-a flow dividing rib plate, 41-a main runner, 42-a parallel second-stage runner, 421-a second-stage main runner, 422-a second-stage branch runner, 43-a water return runner, 431-a first main water return runner, 432-a first-stage branch water return runner, 433-a second-stage branch water return runner, 44-a first-stage runner, 441-a first-stage main runner, 442-a first-stage branch water return runner and 443-a first-stage water return runner.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. The positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the present patent.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are the terms "upper", "lower", "left", "right", "long", "short", etc. indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore the terms describing the positional relationship in the drawings are only for illustrative purposes and are not to be construed as limiting the present patent, and those skilled in the art will understand the specific meaning of the terms according to their specific circumstances. The term "plurality" as used herein means an integer equal to or greater than 2 in number.

The technical solution of the present invention is further described in detail by the following specific embodiments in combination with the accompanying drawings:

the battery pack in the art includes a case body and a cover plate (not shown here), and the space formed by covering the case body and the cover plate is used for accommodating a battery module, and the battery module contains a plurality of battery cells. The application has

Example 1

As shown in fig. 1 to 4, the battery pack includes a case body 1, the case body 1 includes a flow passage 4,

as shown in fig. 3 and 4, the flow channel 4 includes a main flow channel 41, a second-stage flow channel 42 and a water return flow channel 43, the main flow channel 41 is respectively communicated with the second-stage flow channels 42, the second-stage flow channels 42 are respectively communicated with the water return flow channel 43, the main flow channel 41 is connected with the liquid inlet interface 5, and the water return flow channel 43 is communicated with the liquid outlet interface 6. In this embodiment, there are at least two sets of the second-stage runners 42 connected in parallel, and the two sets of the second-stage runners are respectively located on two sides of the water return runner 43. The cooling liquid enters the main flow channel 41 through the liquid inlet interface 5, the main flow channel 41 is divided into at least two groups of second-stage flow channels 42 which are connected in parallel, and then the second-stage flow channels converge into a group of water return flow channels 43, the structure of the flow channel 4 in the scheme ensures that the bottom of each module is fully distributed with the flow channels, and the consistency of the heat dissipation capacity of each module is ensured. In addition, the two groups of second-stage flow channels 42 which are connected in parallel are arranged on two sides of the water return flow channel 43, and the water is fed from the second-stage flow channels 42 which are connected in parallel on two sides and discharged from the water return flow channel 43 in the middle, so that the uniform flow distribution is ensured. It should be noted that the parallel second-stage runners 42 are preferably arranged in even number groups, for example, two, four, and six groups, and the parallel second-stage runners 42 are equally arranged on both sides of the return water runner 43 according to the number of groups.

In addition, the structure of the flow passage 4 adopts a series-parallel structure which is connected in parallel in a grading way and then converged into a path of series connection. More specifically, the flow channel 4 is a series-parallel structure in which two paths are connected in parallel, then four paths are connected in parallel, and then one path is converged. The structure of the flow channels 4 which are connected in parallel in a grading way is basically designed symmetrically, so that the flow distribution is further ensured to be uniform. It should be noted that, according to the arrangement of the battery cells, the structure of the flow channel 4 is not limited to the above scheme, and the structure of the flow channel 4 may also adopt a series-parallel structure in which the flow channels are connected in parallel in a graded manner, then connected in parallel in a graded manner and then converged into one path of series connection.

As shown in fig. 4, the parallel second-stage flow passage 42 includes a plurality of second-stage main flow passages 421 communicating with the main flow passage 41, and at least two sets of second-stage branch flow passages 422 having one ends communicating with the second-stage main flow passages 421, and the other ends of the second-stage branch flow passages 422 communicate with the water return flow passage 423. In the embodiment, the second-stage flow channel 42 connected in parallel includes at least two sets of second-stage branch flow channels 422, and the cooling liquid in the main flow channel 41 can be further distributed into the plurality of second-stage branch flow channels 422, so that it can be further ensured that the flow channels 4 are fully distributed at the bottom of each module, and the consistency of the heat dissipation capability of each module is ensured.

In addition, the second-stage branch flow passages 422 are provided with three groups, and the three groups of second-stage branch flow passages 422 are arranged back and forth; the other end of the second-stage branch flow passage 422 located in the middle is communicated with the second-stage branch flow passages 422 on both sides respectively and then communicated with the water return flow passage 43. In this embodiment, three sets of the second-stage branch flow passages 422 are provided, then the three sets of the second-stage branch flow passages 422 are combined into two sets and communicated with the water return flow passage 43, and the second-stage branch flow passages 422 adopt a three-in two-out backflow structure, so that the problems of reduced reynolds coefficient and reduced heat exchange capacity due to reduced flow are solved, and the temperature uniformity is improved.

As shown in fig. 3 and 4, the flow passage 4 further includes a first-stage flow passage 44 for communicating the main flow passage 41 with the second-stage flow passage 42 connected in parallel. In the present embodiment, the second-stage flow channels 42 connected in parallel are communicated with the main flow channel 41 through the first-stage flow channels 44, and the purpose of this arrangement is to divide the cooling liquid from the main flow channel 41, so as to ensure that the cooling liquid is uniformly dispersed and the heat dissipation capability of the module contact surface is consistent. It should be noted that, according to the arrangement of the battery cells, a plurality of branch flow channels may be continuously arranged in parallel between the second-stage flow channel 42 and the water return flow channel 43, and the branch flow channels are further branched from the second-stage flow channel 42 connected in parallel.

As shown in fig. 2 to 4, the first-stage flow passage 44 includes a first-stage main flow passage 441 communicating with the main flow passage 41, a plurality of first-stage branch flow passages 442 communicating with the first-stage main flow passage 441, and a first-stage water return flow passage 443 for communicating with the plurality of first-stage branch flow passages 442, the first-stage water return flow passage 443 communicating with the parallel second-stage flow passage 42. In this embodiment, the first-stage flow channel 44 includes a plurality of first branch flow channels 442, and the first branch flow channels 442 can divide the cooling liquid from the main flow channel 41, so as to ensure uniform distribution of the cooling liquid and uniform heat dissipation capability of the module contact surface. It should be noted that the plurality of first-stage branch flow channels 442 may be formed by disposing the plurality of flow dividing ribs 8 in the flow channel groove 2, and the flow dividing ribs 8, the flow channel groove 2, and the bottom plate 3 form the first-stage branch flow channels 442, and the first-stage branch flow channels 442 ensure that the cooling liquid is uniformly dispersed, thereby ensuring that the heat dissipation capacities of the module contact surfaces are consistent.

The extension lines of the first-stage main flow passage 441, the first-stage branch flow passage 442, and the first-stage return water flow passage 443 are disposed in a parallelogram shape. Because the cross-sectional area of the first-stage branch flow channel 441 is relatively small, and the first-stage main flow channel 441 and the first-stage return flow channel 443 are arranged in parallel, the cooling liquid flowing into each first-stage branch flow channel 442 from the first-stage main flow channel 441 finally returns to the first-stage return flow channel 443 in the same flowing path, so that the flow speed consistency of the cooling liquid in all the first-stage branch flow channels 442 can be ensured, because the flow is uniform, the heat exchange capacity of a single module can be ensured to be consistent, if the heat exchange capacity is inconsistent, the heat dissipation of the single module is not uniform, the temperature difference of each part of the module is large, and the normal operation of the module is influenced.

As shown in fig. 1, 3, and 4, the first-stage runners 44 and the parallel second-stage runners 42 are arranged perpendicular to the cell arrangement direction, and the plurality of first-stage runners 44 and the parallel second-stage runners 42 are respectively symmetrically disposed on two sides of the water return runner 43. In this embodiment, the battery cell arrangement direction is the X axis direction and arranges, and the first stage runner 44 and the second stage runner 42 that connects in parallel are the Y axis direction and arrange, and the first stage runner 44 and the second stage runner 42 that connects in parallel are perpendicular to the battery cell arrangement direction and set up for the temperature uniformity of the first stage runner 44 and the second stage runner 42 that connects in parallel is better. The first-stage flow channel 44 and the parallel second-stage flow channel 42 are respectively symmetrically arranged on two sides of the water return flow channel 43, so that the uniform flow distribution can be further ensured.

The backwater flow channel 43 comprises a first main backwater flow channel 431 communicated with the second-stage flow channels 42 connected in parallel, at least two groups of first-stage branch backwater flow channels 432 communicated with the first main backwater flow channel 431, and a plurality of second-stage branch backwater flow channels 433 communicated with the first-stage branch backwater flow channels 432; the second-stage branch backwater flow passage 432 is communicated with the liquid outlet interface 6. In this embodiment, the return water channel 43 includes at least two sets of the first-stage branch return water channel 432 and the second-stage branch return water channel 433, so that the number of times of return is increased, the temperature uniformity is ensured, and the heat exchange capacity is improved. It should be noted that the multiple sets of parallel second-stage runners 42 are located on two sides of the first-stage branch backwater runner 432, and the multiple sets of first-stage runners 44 are located on two sides of the second-stage branch backwater runner 433. The outlet port 6 is preferably provided at the end of the second-stage branch return water flow passage 433.

As shown in fig. 5 and 6, the cross section of the flow channel 4 is rectangular or semicircular, the liquid outlet port 6 crosses the flow channel 4 and does not contact with the inside of the flow channel 4, specifically, the liquid outlet port 6 adopts a flow channel crossing scheme design that the liquid outlet port first vertically faces upwards and then horizontally crosses the liquid inlet port 5 section, thereby avoiding the liquid inlet port 5 section from adopting an external shunt pipeline and simplifying the design. In addition, the liquid inlet port 5 and the liquid outlet port 6 need to be communicated with an external pipeline, so that the liquid inlet port 5 and the liquid outlet port 6 are arranged on the same side in order to save the length of the external pipeline and the space occupied by the external pipeline.

The box body 1 comprises a runner groove 2, the runner groove 2 is arranged at the bottom of the box body 1, the box body further comprises a bottom plate 3, the bottom plate 3 and the runner groove 2 are sealed to form a runner 4, and a liquid inlet interface 5 and a liquid outlet interface 6 are arranged on the runner 4. In this embodiment, through set up runner groove 2 at box body 1, runner groove 2 and cover and form inclosed runner 4 between runner groove 2's the bottom plate 3, can save battery package inner space in the box body 1 bottom of battery package with battery package runner structure integration like this, improved battery package energy density. In addition, the closed flow channel 4 is simple in structure, and the problem that the cooling liquid leaks due to the fact that a pipeline joint part is arranged in a traditional battery pack cooling system and the structure is complex is solved. The runner duct 2 may be formed by milling, engraving, casting, or the like in the bottom of the box body 1. The bottom plate 3 can be connected to the bottom of the box body 1 of the battery pack in a bonding, welding, riveting or other forms, the cross sections of the bottom plate 3 and the runner groove 2 are closed, and therefore a closed runner 4 can be formed between the bottom plate 3 and the runner groove 2. In addition, also can set up boss structure 7 on box body 1, boss structure 7 is used for the installation of bottom plate 3, and mutually adaptation ground sets up the groove structure with boss structure 7 looks adaptation on the bottom plate 3, for the convenience of installing bottom plate 3 provides the location to make the leakproofness that can guarantee runner 4 better. Of course, a groove may be provided on the box body 1, and a boss structure adapted to the groove may be provided on the bottom plate 3.

Example 2

A battery pack comprises a battery module, a battery core and the box body with a flow channel, wherein the flow channel is integrally T-shaped, adopts a two-path parallel connection structure and a four-path parallel connection structure and is distributed and connected in parallel according to the position of the battery module; the first-stage flow channel 44 and the parallel second-stage flow channel 42 of the flow channel are arranged perpendicular to the arrangement direction of the battery cells; the liquid inlet interface 5 and the liquid outlet interface 6 are arranged on the same side, and the liquid outlet interface 6 crosses the flow passage 4 and is not contacted with the inside of the flow passage 4. The liquid outlet interface 6 adopts a flow channel cross scheme design that the liquid outlet interface firstly vertically faces upwards and then horizontally crosses the section 5 of the liquid inlet interface, thereby avoiding the section 5 of the liquid inlet interface adopting an external shunt pipeline and simplifying the design. In addition, the liquid inlet port 5 and the liquid outlet port 6 need to be communicated with an external pipeline, so that the liquid inlet port 5 and the liquid outlet port 6 are arranged on the same side in order to save the length of the external pipeline and the space occupied by the external pipeline.

The working principle is as follows: through set up runner groove 2 on the box body 1 at the battery package, runner groove 2 and cover and form inclosed runner 4 between runner groove 2's the bottom plate 3, with the runner integration in the box body 1 bottom of battery package, saved battery package inner space, improved battery package energy density. The cooling liquid enters from the liquid inlet interface 5, is divided into two paths from the main flow channel 41 to enter into two groups of first-stage flow channels 44, each group of first-stage flow channels 44 is further branched into two groups of second-stage flow channels 42 which are connected in parallel, then the four groups of second-stage flow channels 42 which are connected in parallel are combined into a group of water return flow channels 43, and finally flows out through the water outlet interface 6 which is communicated with the water return flow channels 43. When the coolant flows in the main flow channel 41, the first-stage flow channel 44, the second-stage flow channel 42 connected in parallel and the return water flow channel 43, the coolant can cool the box body 1, because the bottom of the box body 1 is contacted with the battery module and the battery core, the heat of the battery module and the battery core is mainly gathered at the bottom of the box body 1, and according to the heat exchange principle, the coolant cools the box body 1 and simultaneously achieves the purpose of cooling the battery module and the battery core. Because this battery package runner adopts the series-parallel connection structure, two earlier the way is parallelly connected, and the branch divide the four ways to be parallelly connected, converges into the structure of establishing ties all the way again, and this structure has guaranteed that every module bottom all is covered with runner 4, has guaranteed every module heat-sinking capability uniformity.

It should be noted that, the main flow passage 41, the first stage flow passage 44, the parallel second stage flow passage 42, the first stage main flow passage 441, the first stage branch flow passage 442, the first stage return water flow passage 443, the second stage main flow passage 421, and the second stage branch flow passage 442 are named for convenience of distinction, and do not represent the functions of the main flow passage in the technical solutions, and do not limit the protection scope thereof.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations to the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The utility model provides a battery pack, battery pack includes box body (1) and apron, its characterized in that: the box body (1) comprises a flow channel (4), and the flow channel (4) comprises a main flow channel (41), a second-stage flow channel (42) and a water return flow channel (43) which are connected in parallel; the main flow channel (41) is respectively communicated with second-stage flow channels (42) which are connected in parallel, and the second-stage flow channels (42) which are connected in parallel are respectively communicated with a water return flow channel (43); the parallel second-stage flow channel (42) is arranged on two sides of the water return flow channel (43), a liquid inlet interface (5) is arranged on the main flow channel (41), and a liquid outlet interface (6) is arranged on the water return flow channel (43).

2. The battery pack according to claim 1, wherein: the structure of the flow channel (4) adopts a series-parallel structure which is connected in parallel in a grading way and then converged into one way in series.

3. The battery pack according to claim 2, wherein: the structure of the flow channel (4) adopts a series-parallel structure that two paths are firstly connected in parallel, then four paths are connected in parallel and then converged into one path to be connected in series.

4. The battery pack according to claim 2 or 3, wherein: the parallel second-stage flow channels (42) are four-way parallel, each second-stage flow channel (42) comprises a plurality of second-stage main flow channels (421) communicated with the main flow channel (41), at least two groups of second-stage branch flow channels (422) with one ends communicated with the second-stage main flow channels (421), and the other ends of the second-stage branch flow channels (422) are communicated with the water return flow channel (43).

5. The battery pack according to claim 4, wherein: three groups of second branch flow channels (422) are arranged, and the three groups of second branch flow channels (422) are arranged back and forth; the other end of the second-stage branch flow passage (422) in the middle is communicated with the second-stage branch flow passages (422) on the two sides respectively and then communicated with the water return flow passage (43).

6. The battery pack according to claim 2 or 3, wherein: the flow channel (4) further comprises a first-stage flow channel (44) for communicating the main flow channel (41) with the parallel second-stage flow channel (42).

7. The battery pack according to claim 6, wherein: the first-stage flow channel (44) comprises a first-stage main flow channel (441) communicated with the main flow channel (41), a plurality of first-stage branch flow channels (442) communicated with the first-stage main flow channel (441), and a first-stage water return flow channel (443) for communicating the plurality of first-stage branch flow channels (442), wherein the first-stage water return flow channel (443) is communicated with the parallel second-stage flow channel (42).

8. The battery pack according to any one of claims 1, 2, 3, 5, and 7, wherein: the water return flow channel (43) comprises a first main water return flow channel (431) communicated with the second-stage flow channels (42) connected in parallel, at least two groups of first-stage branch water return flow channels (432) communicated with the first main water return flow channel (431), and a plurality of second-stage branch water return flow channels (433) communicated with the first-stage branch water return flow channels (432); the second-stage branch backwater flow passage (433) is communicated with the liquid outlet interface (6).

9. The battery pack according to claim 2 or 3, wherein: the box body (1) comprises a runner groove (2), the runner groove (2) is formed in the bottom of the box body (1), the box body (1) further comprises a bottom plate (3), and the bottom plate (3) and the runner groove (2) are sealed to form a runner (4).

10. The battery pack according to claim 1, wherein: the box body (1) and the cover plate cover to form an accommodating space for accommodating the battery module; the whole flow channel is T-shaped, adopts a two-path parallel connection structure and a four-path parallel connection structure and is distributed in parallel according to the position of the battery module in an adaptive manner; the first-stage flow channel (44) and the parallel second-stage flow channel (42) of the flow channel are arranged in a direction perpendicular to the arrangement direction of the battery cores in the battery module; the liquid inlet interface (5) and the liquid outlet interface (6) are arranged on the same side, and the liquid outlet interface (6) spans the flow channel (4) and is not contacted with the inside of the flow channel (4).