WO2022053487A1

WO2022053487A1 - Cooling device for power battery system and power battery system for vehicle

Info

Publication number: WO2022053487A1
Application number: PCT/EP2021/074665
Authority: WO
Inventors: Tony Zhang; Bogart LIU; Wei Qu
Original assignee: Webasto SE
Priority date: 2020-09-08
Filing date: 2021-09-08
Publication date: 2022-03-17
Also published as: CN212659592U

Abstract

11 ABSTRACT The present disclosure provides a cooling device for a power battery system and a power battery system for a vehicle. The cooling device is arranged at the bottom of the power battery system and comprises: a box frame for supporting and fixing the power battery system; a liquid- cooling plate assembly configured as an integral type and arranged on the box frame; and a middle 5 beam detachably fixed on the box frame to limit the liquid-cooling plate assembly. In the cooling device of this disclosure, the application of the integral liquid-cooling plate assembly inside the battery pack is realized. It can realize the pipeline-free design, avoid the risk of internal leakage of the coolant, and greatly improve the safety performance of the battery system. Moreover, the detachable design of the middle beam can simplify the assembly steps, thereby saving assembly 10 procedures and time, and improving production efficiency. FIG.2a

Description

COOLING DEVICE FOR POWER BATTERY SYSTEM AND POWER BATTERY SYSTEM FOR VEHICLE

FIELD OF THE INVENTION

The present disclosure generally relates to the field of vehicles, especially the field of power battery system for new energy vehicles (electric vehicles, hybrid vehicles). More specifically, it relates to a cooling device for a power battery system, and a power battery system for a vehicle.

BACKGROUND OF THE INVENTION

Hybrid vehicles and pure electric vehicles usually require high-efficiency power battery systems to provide energy. When running at high power, a large amount of heat will be generated during the charging and discharging process of the battery, which will accumulate heat inside the battery and cause the performance of the battery to decrease. Since the power battery is sensitive to temperature, in order to make the power battery work at the optimal temperature, more and more battery systems are currently equipped with cooling systems for cooling such as by air or liquid. Due to low heat transfer coefficient and slow heat transfer speed of the air cooling, the liquid cooling system is the most common.

At present, the cooling structure of battery packs on the market is mostly made by the method of aluminum extrusion or aluminum stamping. The parts for fixing the battery modules and the cooling box are usually welded as a whole, and the liquid-cooling plate or cooling plate is divided into multiple portions. As shown in Fig. 1 , a plurality of cooling plates 1 are installed with pipe joints 2 to realize a liquid cooling cycle.

However, the cooling structure of this kind of battery pack generally has a risk of pipeline leakage, and the failure probability is high, which may cause the battery system to short-circuit, catch fire or even explode, and cause high safety risk. In addition, the pipeline connection system is complicated, the assembly is time-consuming, and the cost and processing efficiency are relatively low.

SUMMARY OF THE INVENTION

The object of the present disclosure is to solve the above-mentioned problems in the prior art and provide a box design for an internal integrated cooling plate, so as to realize the application of the integrated liquid-cooling plate inside the battery pack. It can realize pipeline-free and avoid the risk of internal coolant leakage. Even if the coolant leaks, it will not affect the high-voltage components and modules inside the battery system, which greatly improves safety.

To this end, according to one aspect of the present disclosure, a cooling device for a power battery system is provided. The cooling device is arranged at the bottom of the power battery system and comprises a box frame for supporting and fixing the power battery system; a liquid-cooling plate assembly configured as an integral type and arranged on the box frame; and a middle beam detachably fixed on the box frame to limit the liquid-cooling plate assembly.

According to the above technical concept, the present disclosure may further include any one or more of the following optional forms.

In some optional forms, the liquid-cooling plate assembly comprises a plurality of liquid-cooling plates arranged side by side and a pair of connecting plates connecting the plurality of liquid-cooling plates at both ends of each liquid-cooling plate, so that the one or more adjacent liquid-cooling plates are in fluid communication to form a cooling circuit.

In some optional forms, the connecting plate is provided with a liquid inlet pipe and a liquid outlet pipe, and the liquid inlet pipe and the liquid outlet pipe are in fluid communication with one or more liquid-cooling plates.

In some optional forms, the plurality of liquid-cooling plates and the connecting plates are extruded hollow metal plates and are hermetically welded to each other.

In some optional forms, the plurality of liquid-cooling plates are arranged to define a notch for accommodating the middle beam.

In some optional forms, the box frame comprises a pallet and an inner reinforcing beam placed in the pallet and/or an outer reinforcing beam located at the bottom of the pallet; the inner reinforcing beam is arranged around the periphery of the pallet to make the middle beam to be detachably fixed on the inner reinforcing beam, and the outer reinforcing beam is provided with a fixing part for connecting vehicle components.

In some optional forms, the middle beam is configured as a frame comprising a pair of crossbeams which span the transverse direction or the longitudinal direction of the box frame and a pair of connecting beams detachably fixed to the box frame, and the pair of crossbeams are fixedly connected to the pair of connecting beams.

In some optional forms, the connecting beams and the crossbeams are hollow sheet metal, wherein the crossbeams and/or the connecting beams are provided with reinforcing ribs, and/or reinforcing beams are arranged between the pair of crossbeams and/or between the pair of connecting beams.

In some optional forms, the connecting beam is configured to comprise a first connecting beam connected to the crossbeam and a second connecting beam connected to the first connecting beam, and the middle beam is connected to the box frame through the second connecting beam.

According to another aspect of the present disclosure, a power battery system for a vehicle is provided. The power battery system comprises at least one cooling device as described above.

In the cooling device of the present disclosure, the application of the integral liquid-cooling plate assembly inside the battery pack is realized. It can realize the pipeline-free design, avoid the risk of internal leakage of the coolant, and greatly improve the safety performance of the battery system. Moreover, the detachable design of the middle beam can simplify the assembly steps, thereby saving assembly procedures and time, and improving production efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The other features and advantages of the present disclosure will be better understood through the following optional embodiments described in detail in conjunction with the accompanying drawings. The same reference signs in the accompanying drawings identify the same or similar components, in which:

FIG. 1 is a schematic view of a cooling structure of a conventional battery pack;

FIG. 2a is a schematic view of a cooling device of a power battery system according to an embodiment of the present disclosure, and FIG. 2b is a schematic top view of the cooling device in FIG. 2a;

FIG. 3 is an exploded schematic view of the cooling device in FIG. 2a;

FIG. 4a is a schematic view of the liquid-cooling plate assembly, and FIG. 4b is a schematic top view of the liquid-cooling plate assembly in FIG. 4a;

FIG. 5a is an exploded schematic view of the box frame, and FIG. 5b is a schematic view of the installation surface of the box frame for installing components, liquid inlet pipe and liquid outlet pipe;

FIG. 6a is a schematic view of the middle beam shown in FIG. 2a, FIG. 6b is a schematic cross- sectional view taken along the line A-A in FIG. 6a, and FIG. 6c is a schematic cross-sectional view taken along the line B-B in FIG. 6a;

FIG. 7a is a schematic view of the middle beam of the cooling device installed on the box frame, in which the liquid-cooling plate assembly is removed, and FIG. 7b is a schematic top view of the cooling device in FIG. 7a.

DETAILED DESCRIPTION OF EMBODIMENTS

The implementation and use of the embodiments are discussed in detail below. However, it should be understood that the specific embodiments discussed only exemplarily illustrate specific ways of implementing and using the present disclosure, rather than limiting the scope of the present disclosure. In the description, the structural position of each component, such as up, down, top, bottom, etc., is not absolute, but relative. When the various parts are arranged as shown in the figures, these direction expressions are appropriate, but when the position of each part in the figures changes, these direction expressions also change accordingly.

Herein, unless expressly specified and limited otherwise, the terms "install", "connect", "fix" and other terms should be interpreted broadly. For example, it can be a fixed connection or a detachable connection, or it can be integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above-mentioned terms in this text can be understood according to the specific situation.

Herein, "transverse" and "longitudinal" are relative terms, "transverse" refers to a direction that is relatively small in size, and "longitudinal" refers to a direction that is relatively large in size.

Generally, a power battery system for a vehicle includes a battery pack composed of a plurality of single cells, and a cooling device is arranged at the bottom of the power battery system, which helps to quickly and uniformly dissipate heat from the battery pack. According to the concept of the present disclosure, a liquid-cooling plate assembly is advantageously constructed as an integral type to avoid the risk of leakage of the coolant. The integral liquid-cooling plate assembly can realize the overall assembly and disassembly, which simplifies the assembly process. In addition, a middle beam is provided to be detachably connected to a box frame supporting the liquid-cooling plate assembly, so as to provide a stable limiting effect on the liquid-cooling plate assembly.

Specifically, referring to FIGS. 2a to 3, the cooling device according to the present disclosure may include a box frame 20 for supporting and fixing the power battery system, a liquid-cooling plate assembly 10 arranged on the box frame 20, and a middle beam 30 detachably fixed on the box frame 20 to limit the liquid-cooling plate assembly 10. Preferably, although not shown, a thermally conductive gasket may be provided between the liquid-cooling plate assembly 10 and the battery modules to enhance the heat dissipation effect.

In some embodiments, referring to FIGS. 4a and 4b, the liquid-cooling plate assembly 10 may include a plurality of liquid-cooling plates 12 arranged side by side and a pair of connecting plates 11 connecting the plurality of liquid-cooling plates 12 at both ends of each liquid cooling plate 12 so that one or more adjacent liquid-cooling plates 12 are in fluid communication to form a cooling circuit. The connecting plate 11 is provided with a liquid inlet pipe 13 and a liquid outlet pipe 14, which for example, are exemplarily arranged on the connecting plate 11a of the pair of connecting plates in FIG. 4b. The liquid inlet pipe 13 and the liquid outlet pipe 14 can be used as a liquid inlet joint and a liquid outlet joint to be connected to a liquid supply pipe and a liquid discharge pipe. The liquid inlet pipe 13 and the liquid outlet pipe 14 can also be in fluid communication with one or more liquidcooling plates 12, so as to form different cooling circuits according to actual needs. For example, as shown in FIG. 4b, the coolant that enters the connecting plate 11a through the liquid inlet pipe 13 can enter the several liquid-cooling plates 12a on the left side to be diverged and then enter the several liquid-cooling plates 12b on the right side to be diverged after being converged on the connecting plate 11 b, and then converge on the connecting plate 11a to be discharged through the liquid outlet pipe 14, thereby achieving the purpose of circulating cooling and ensuring that the power battery works in an environment with a basically constant temperature.

In some embodiments, the plurality of liquid-cooling plates 12 and the connecting plates 11 may be extruded hollow metal plates and hermetically welded to each other, so as to be combined to form as a whole. Optionally, the entire liquid-cooling plate assembly can be welded and formed by aluminum or aluminum alloy extruded profiles. In this way, the liquid-cooling plate assembly adopts a pipeline-free design, which avoids the risk of leakage and additional assembly time for pipeline connections. In addition, the use of aluminum can achieve a lightweight design with reduced weight, low cost and efficient heat transfer. In consideration of the layout of the liquid-cooling plates and the connecting plates, a reasonable flow channel design can reduce the flow resistance of the coolant and improve the heat transfer efficiency.

In some embodiments, a plurality of liquid-cooling plates 12 are arranged to define a notch 15 for receiving the middle beam 30, as shown in FIG. 4b. The notch 15 can be configured to be compatible with the size of the middle beam 30. In this way, when the liquid-cooling plate assembly 10 is installed in the box frame 20 and the middle beam 30 is placed in the notch 15, as shown in FIG. 2a, the overall size of the cooling device can be more compact. In the embodiment shown in FIG. 4b, five liquid-cooling plates can be arranged on the left and right sides respectively, and a notch 15 is remained in the middle to ensure the uniform temperature field distribution of the liquidcooling plates and effectively reduce the system pressure drop to improve the heat dissipation effect. It should be understood that in practical applications, more or fewer liquid-cooling plates can be arranged as required. In addition, the middle here does not mean that it is necessarily located in the middle, and the number of the middle beam is not limited to one.

FIG. 5a shows an embodiment of the box frame 20. In this embodiment, the box frame 20 may include a pallet 21 and an inner reinforcing beam 22 placed in the pallet 21 and/or an outer reinforcing beam 23 located at the bottom of the pallet 21 . Advantageously, the box frame 20 is configured to provide structural features such as installation and fixing points for battery modules, installation and fixing points for internal electrical components, and connection and fixing points for the entire vehicle. For example, in some embodiments, the inner reinforcing beam 22 may be arranged around the periphery of the pallet 21 , as shown in FIGS. 2a and 5a, and provide installation and fixing points (for example, the threaded holes 221 shown in FIG. 7a) for the battery modules, and the installation and fixing points for the middle beam, so that the middle beam 30 can be detachably fixed to the inner reinforcing beam 22. For the outer reinforcing beam 23, a fixing part 24 for connecting vehicle components is optionally provided. Moreover, the pallet 21 is configured to provide a space for accommodating the liquid-cooling plate assembly 10 and the middle beam 30, that is, a vertical wall may be provided on the periphery of the pallet 21 , and an installation surface 25 having a component interface and an installation interface for the liquid inlet pipe and the liquid outlet pipe may be provided on the vertical wall. For details, referring to FIG. 5b, the installation surface 25 is provided with, for example, a component interface 251 for connecting high and low voltage connectors, an installation interface 252 of the liquid inlet pipe 13 and an installation interface 253 of the liquid outlet pipe 14. In some embodiments, the liquid inlet pipe 13 and the liquid outlet pipe 14 can be provided with a mounting block 16 to further ensure the connection stability. In combination with FIGS. 3, 4b and 5b, the mounting block 16 can be installed in the corresponding hole on the installation surface 25 by, for example, a fastener 42 such as a bolt.

FIGS. 6a to 6c illustrate an embodiment of the middle beam 30. In this embodiment, the middle beam 30 can be configured as a frame, so that the electronic control elements can be accommodated in the frame. In some embodiments, the middle beam 30 includes, for example, a pair of crossbeams 31 spanning the transverse direction or the longitudinal direction of the box frame 20, and a pair of connecting beams 32 detachably fixed to the box frame 20, and the pair of crossbeams 31 and the pair of connecting beams 32 are fixedly connected, for example, by welding.

The middle beam 30 is not only provided to limit and fix the liquid-cooling plate assembly 10 to the box frame 20, the middle beam 30 can also play a role in bearing the weight of the battery modules. For example, threaded holes 312 may be provided on the pair of crossbeams 31 , as shown in FIG. 6a. As a result, the battery modules can be installed in place with stable support through the threaded holes 221 on the inner reinforcing beam 22 of the box frame 20 and the threaded holes 312 on the middle beam 30, as shown in FIG. 7a. Preferably, the connecting beam 32 and the crossbeam 31 may be hollow sheet metal, as shown in FIGS. 6b and 6c, the section of the profile is used to increase the rigidity and strength. In some embodiments, the crossbeam 31 and/or the connecting beam 32 may be provided with reinforcing ribs. For example, one or more reinforcing ribs 311 are extended on the crossbeam 31 as shown in FIG. 6b to increase the strength. In some embodiments, reinforcing beams may also be provided between the pair of crossbeams 31 and/or between the pair of connecting beams 32.

As mentioned above, the liquid-cooling plate assembly 10 is provided with the notch for accommodating the middle beam 30. In this case, the connecting beam 32 of the middle beam 30 can be used as the first connecting beam connected to the crossbeam 31 , and it may also include a second connecting beam 33 connected to the first connecting beam, as shown in FIG. 6a. The middle beam 30 is connected to the box frame 20 through the second connecting beam 33, as shown in FIGS. 7a and 7b.

The box frame 20 and the middle beam 30 can be made of high-strength steel sheet metal, and each component is welded to each other by welding. Alternatively, the above-mentioned welding method can be selected as cold metal transfer (CMT) welding, friction stir welding or molt inert gas (MIG) welding. The connection between the middle beam 30 and the box frame 20 may be in the form of fasteners 41 such as bolts, for example, as shown in FIG. 3. In this way, it can be realized that the integral liquid-cooling plate assembly 10 is installed in the box frame 20 in advance, and then the middle beam 30 is installed and fixed on the box frame 20, and then the liquid-cooling plate assembly 10 is fixed to the box frame 20. The advantage of this design is that the liquid-cooling plate assembly 10 can be conveniently replaced or repaired according to actual needs. In general, the cooling device of the present disclosure meets the function and strength requirements, avoids the risk of internal liquid leakage, and improves the safety and reliability of the power battery system. It is simple to assemble and greatly improves the production efficiency.

It should be understood that the embodiments shown in the figures only show the optional shape, size, and arrangement of the cooling device according to the present disclosure, but it is only for illustration and not limitation. Other shapes, sizes and arrangements can be adopted without departing from the idea and scope of the present disclosure.

The technical content and technical features of the present disclosure have been disclosed above.

However, it should be understood that those skilled in the art can make various variations and improvements to the above disclosed concepts under the inventive idea of the present disclosure, and all these variations and improvements belong to the scope of protection of the present disclosure. The description for the above embodiments is illustrative and not restrictive, and the scope of protection of the present disclosure is determined by the claims.

Claims

9 CLAIMS

1 . A cooling device for a power battery system, wherein the cooling device is arranged at the bottom of the power battery system and comprises: a box frame for supporting and fixing the power battery system; a liquid-cooling plate assembly configured as an integral type and arranged on the box frame; and a middle beam detachably fixed on the box frame to limit the liquid-cooling plate assembly.

2. The cooling device of a power battery system according to claim 1 , wherein the liquid-cooling plate assembly comprises a plurality of liquid-cooling plates arranged side by side and a pair of connecting plates connecting the plurality of liquid-cooling plates at both ends of each liquid-cooling plate, so that one or more adjacent liquid-cooling plates are in fluid communication to form a cooling circuit.

3. The cooling device of a power battery system according to claim 2, wherein the connecting plate is provided with a liquid inlet pipe and a liquid outlet pipe, and the liquid inlet pipe and the liquid outlet pipe are in fluid communication with one or more liquid-cooling plates.

4. The cooling device of a power battery system according to claim 2 or 3, wherein the plurality of liquid-cooling plates and the connecting plates are extruded hollow metal plates and are hermetically welded to each other.

5. The cooling device of a power battery system according to claim 2 or 3, wherein the plurality of liquid-cooling plates are arranged to define a notch for accommodating the middle beam.

6. The cooling device of a power battery system according to claim 1 , wherein the box frame comprises a pallet and an inner reinforcing beam placed in the pallet and/or an outer reinforcing beam located at the bottom of the pallet; the inner reinforcing beam being arranged around the periphery of the pallet to make the middle beam to be detachably fixed on the inner reinforcing beam, and the outer reinforcing beam is provided with a fixing part for connecting vehicle components.

7. The cooling device of a power battery system according to claim 1 , wherein the middle beam is configured as a frame comprising a pair of crossbeams which span the transverse direction or the longitudinal direction of the box frame and a pair of connecting beams detachably fixed to the box frame, and the pair of crossbeams are fixedly connected to the pair of connecting beams.

8. The cooling device of a power battery system according to claim 7, wherein the connecting beams and the crossbeams are hollow sheet metal, wherein the crossbeams and/or the connecting beams are provided with reinforcing ribs, and /or reinforcing beams are arranged between the pair of crossbeams and/or between the pair of connecting beams.

9. The cooling device of a power battery system according to claim 7 or 8, wherein the connecting beam is configured to comprise a first connecting beam connected to the crossbeam and a second connecting beam connected to the first connecting beam, and the middle beam is connected to the box frame through the second connecting beam.

10. A power battery system for a vehicle, wherein the power battery system comprises at least one cooling device of a power battery system according to any one of claims 1 to 9.