WO2019166241A1

WO2019166241A1 - Watercold plate for battery module

Info

Publication number: WO2019166241A1
Application number: PCT/EP2019/053833
Authority: WO
Inventors: Xu KUNHAO
Original assignee: Gränges Aluminium (Shanghai) Co., Ltd; Gränges Ab
Priority date: 2018-02-27
Filing date: 2019-02-15
Publication date: 2019-09-06
Also published as: CN110197935A; CN110197935B

Abstract

This invention relates to a water cold plate for a battery module, wherein the water cold plate comprises a cover plate (1), a bottom plate (2) and a plurality of heat dissipation fins (3) which are integrally fixed, and a closed heat dissipation flow channel is formed between the cover plate (1) and the bottom plate (2), wherein an inlet end and an outlet end of the heat dissipation flow channel are respectively in fluid communication with a fluid inlet tube (4) and a fluid outlet tube (5) such that a liquid cooling medium flows in the heat dissipation flow channel, and the plurality of heat dissipation fins (3) are spaced apart from each other and perpendicularly inserted into the cover plate (1) to be in communication with the heat dissipation flow channel, wherein a plurality of battery cells (6) of the battery module are capable of being placed in spaces between the plurality of heat dissipation fins (3), so that heat of the battery cells (6) is transmitted to the liquid cooling medium in the heat dissipation flow channel via the heat dissipation fins (3).

Description

WATERCOLD PLATE FOR BATTERY MODULE Field of the Invention

The present invention generally relates to the technical field of cooling system, and more particularly to a finned water cold plate for battery thermal management in electric vehicles.

Background of the Invention

In the field of battery thermal management in the electric vehicles, the so-called cold plate (cooling plate) is capable of absorbing the heat of an object to be cooled by using the temperature difference between an outer surface of the cold plate and a contact surface of the object to be cooled, that is, performing cooling; conversely, if the temperature is higher than the object to be cooled, it can be used for heating. In this field, this kind of member is referred to as a cold plate or a cooling plate, whether it has a heating function or not. The so- called water cold plate (water cooling plate) means that the cooling medium inside is a liquid, such as water. The water has a high specific heat capacity, so it can store a large amount of heat, and the water in the water cold plate can be still and cool or heat the object to be cooled only depending on the initial temperature difference. However, in most cases, in order to ensure continuous operation, the water is flowing, that is, the water heated or cooled by absorbing or releasing heat in the cold plate would flow to another section in the circuit for cooling or heating. This situation can be expressed graphically as water being a carrier.

At present, the mainstream battery water cooling plate usually adopts an extruded profile, and the thinnest wall thickness of about 3 mm can be achieved by the process disclosed in the patent document W02017021018 A1. In practical applications, the height of the flow channel is 3~6mm, and the utilization efficiency of the structural parts is relatively low. The water cooling system does not need to withstand large water-side working pressure, and thus the wall thickness can be absolutely thinned. Therefore, from the perspective of the lightweight vehicle and the improving of the energy density of the power battery pack or module, it is preferable to use a thin-walled aluminum plate (the thickness is less than 1.5 mm) to be welded to form an inner flow channel, for example, as disclosed in the patent document US2009325059 A1. However, in this solution the water cooling flow channel is formed by brazing for only a single battery cell, and the cooling plate assembly which constitutes the battery module still adopts assembly solution, that is, the main water pipe is mechanically sealed to inlet and outlet of the cooling plate between the battery cells. As a result, there are a large number of connection portions in the system that need to be sealed, which causes a certain risk of leakage during use.

Further, the solution disclosed in the patent document US20120107663 A1 proposes an integrally brazed water cold plate solution suitable for a single module or an entire battery pack. However, when the cold plate in this solution is placed at the bottom of the battery module to cool the battery pack, due to the inevitable gap (such as the influence of surface roughness), there is a large contact thermal resistance as the battery conducts heat to the cooling plate through the bottom. Heat conductive pad or heat conductive adhesive has been currently used, but the thermal conductivity of the filled area is only a single digit, which is still the biggest obstacle in the heat exchange path. If there is a unique heat transmission path to transmit the heat to the liquid in the cold plate through the bottom of the battery cell, it is difficult to control the temperature difference between the bottom and the top of the battery cell in a small range.

Summary of the Invention

In order to solve the above-mentioned problems in the prior art, the present invention proposes a water cold plate solution with more effective heat transmission. By increasing the heat transmission path, that is, via a plurality of heat dissipation fins sandwiched between battery cells of a battery module, the heat is transmitted from the side of the battery cells to the bottom of the fins directly contacting with the cooling medium, and then the heat is carried away by the cooling medium, without passing through a heat transmission bottle neck section between the bottom of the battery and the cold plate in the prior art.

To this end, according to the technical concept of the present invention, a water cold plate for a battery module is provided, wherein the water cold plate comprises a cover plate, a bottom plate and a plurality of heat dissipation fins which are integrally fixed, preferably brazed, and a closed heat dissipation flow channel is formed between the cover plate and the bottom plate, wherein an inlet end and an outlet end of the heat dissipation flow channel are respectively in fluid communication with a fluid inlet tube and a fluid outlet tube such that a liquid cooling medium flows in the heat dissipation flow channel, and the plurality of heat dissipation fins are spaced apart from each other and perpendicularly inserted into the cover plate to be in communication with the heat dissipation flow channel, and wherein a plurality of battery cells of the battery module are capable of being placed in spaces between the plurality of heat dissipation fins, so that the heat of the battery cells is transmitted to the liquid cooling medium in the heat dissipation flow channel via the heat dissipation fins.

According to the above technical concept, the present invention can further include one or more following optional forms.

In some preferred forms, the cover plate is provided with a plurality of slits for inserting the plurality of heat dissipation fins, wherein each slit perpendicularly extends a portion from a side edge of the cover plate towards an opposite side edge, and the plurality of slits extending along different side edges are staggered from each other.

In some preferred forms, the bottom plate is provided with a plurality of grooves in the positions corresponding to the plurality of slits, and the heat dissipation fins are restricted by the slits and the grooves. In some preferred forms, an insertion edge of each heat dissipation fin is provided with an insertion section for inserting into the slit and a contact section for contacting a surface of the cover plate, and the depth of the insertion section being inserted into the slit is substantially equal to the height of the heat dissipation flow channel.

In some preferred forms, the contact section has a flanging edge for abutting against the surface of the cover plate.

In some preferred forms, a flanging edge is formed at a periphery of the cover plate and/or the bottom plate for restricting the cover plate and the bottom plate.

In some preferred forms, a heat conductive member, such as a pad and/or a heat conductive adhesive is arranged between the battery cells and also between the battery cells, the heat dissipation fins and the cover plate.

In some preferred forms, the inlet end and the outlet end of the heat dissipation flow channel are arranged on the cover plate or the bottom plate.

The liquid cooling medium may be any suitable liquid used in thermal management, such as water based liquids or other kinds of refrigerants. Water based liquids may include water with optional additives, for example for preventing freezing or inhibiting corrosion. Such liquids include cooling water, chilled water or coolant.

In some preferred forms, the water cold plate is configured for the battery thermal management in an electric vehicle.

When the water cold plate according to the present invention is used to the battery thermal management of an electric vehicle, the problem of uneven heat dissipation of the battery system with high heat density can be effectively solved, and the surface temperature uniformity of the battery cells is good; the water cold plate has simple structure, light weight, easy production and low cost; the water cold plate is preferably integrally brazed to minimize the risk of leakage, thus it can be used reliably and can be widely used for the thermal management of the electric battery in the new energy vehicles.

Brief Description of the Drawings

Other features and advantages of the present invention will be better understood with reference to the following detailed description when taken in conjunction with the accompanying drawings, and the same reference numerals in the drawings indicate the same or similar members, in which:

Fig. 1 is a schematic view of a water cold plate according to a preferred embodiment of the present invention;

Fig. 2 is a schematic view of a cover plate of the water cold plate; Fig. 3 is a schematic view of a bottom plate of the water cold plate;

Fig. 4 is a partial sectional view showing that the cover plate and the bottom plate are restricted by a flanging edge;

Fig. 5 is a schematic view of heat dissipation fins of the water cold plate;

Fig. 6 is a side view showing that the water cold plate of Fig. 1 is used in a battery module;

Fig. 7 is a sectional view taken along line A-A in Fig. 6; and

Fig. 8 is a schematic view showing the flow of a liquid cooling medium inside the water cold plate, wherein only the heat dissipation fins are shown for simplification.

Description of Embodiments

The implementation and use of the embodiments are discussed in detail below. However, it should be understood that the discussed embodiments of the present invention are only illustrative of the specific embodiments of the present invention and are not intended to limit the scope of the invention. In the description, the orientation representations of the structural positions of various components, such as up, down, top, bottom, etc., are not absolute, but rather relative. These orientation representations are appropriate when the various components are arranged as shown in the figures, but change accordingly when the positions of the various components in the drawings change.

As used herein,“electric vehicles” means generalized new energy vehicles, including battery electric vehicle (BEV), plug-in hybrid electric vehicle (PHEV), and fuel cell electric vehicle (FCEV). The water cold plate of the present invention can be widely used for battery thermal management of a vehicle power source of such new energy vehicles.

With reference to the preferable embodiment as shown in Figs.1-5, the water cold plate of the present invention comprises a cover plate 1 , a bottom plate 2 and a plurality of heat dissipation fins 3 which are brazed integrally, wherein a closed heat dissipation flow channel is formed between the cover plate 1 and the bottom plate 2. An inlet end and an outlet end of the heat dissipation flow channel are respectively in fluid communication with a fluid inlet tube 4 and a fluid outlet tube 5 such that a liquid cooling medium flows in the heat dissipation flow channel. In this embodiment, the inlet end and the outlet end of the heat dissipation flow channel are configured as a fluid inlet tube mounting hole 1 c and a fluid outlet tube mounting hole 1 d formed in the cover plate 1 , as shown in Fig. 2. In some embodiments, the inlet end and the outlet end of the heat dissipation flow channel may also be formed in the bottom plate 2.

The plurality of heat dissipation fins 3 are spaced apart and parallel to each other, and inserted perpendicularly into the cover plate 1 to be in communication with the heat dissipation flow channel. In this embodiment, the cover plate 1 is provided with a plurality of slits 1 a for inserting the plurality of heat dissipation fins 3, and the slits 1 a may be formed by stamping. Preferably, each slit 1 a perpendicularly extends a portion from a side edge of the cover plate 1 towards an opposite side edge, and the plurality of slits extending along different side edges are staggered from each other. In this way, when the plurality of heat dissipation fins 3 are inserted into corresponding slits 1 a, a S-shaped heat dissipation flow channel is formed between the cover plate 1 and the bottom plate 2, thereby promoting the sufficient absorption and dissipation of the heat. Accordingly, as shown in Fig. 5, an insertion edge of each heat dissipation fins 3 is provided with an insertion section 3b for inserting into the slit 1 a and a contact section 3a for contacting a surface of the cover plate 1. Advantageously, the depth of the insertion section 3b being inserted into the slit 1 a is substantially equal to a height of the heat dissipation flow channel.

In order to better restrict each heat dissipation fin 3, the bottom plate 2 is provided with a plurality of grooves 2a in the positions corresponding to the plurality of slits 1 a, as shown in Fig. 3. The grooves 2a may be formed by stamping to be shaped as a projecting rib projecting from the surface of the bottom plate 2 accordingly, thus the heat dissipation fins 3 are restricted by the slits 1 a together with the grooves 2a.

In a preferred embodiment, the periphery of the cover plate 1 may be stamped with a flanging edge 1 b. Alternatively, the periphery of the bottom plate 2 may also be stamped with a flanging edge 2b. As best shown in Fig. 4, the cover plate 1 and the bottom plate 2 can be assembled fixedly by restricting and fixing the flanging edge 1 b of the cover plate 1 and the flanging edge 2b of the bottom plate 2 relative to each other. Thereafter, the plurality of heat dissipation fins 3 are inserted into the slits 1 a of the cover plate 1 while the fluid inlet tube 4 is inserted into the fluid inlet tube mounting hole 1 c of the cover plate 1 , and the fluid outlet tube 5 is inserted into the fluid outlet tube mounting hole 1 d of the cover plate 1. In a preferred embodiment, the contact portion 3a of the heat dissipation fin 3 in contact with the surface of the cover plate 1 may be formed with a flanging edge by stamping or sheet metal processing to facilitate abutment with the surface of the cover plate. The fluid inlet tube 4 and the fluid outlet tube 5 can control the depth thereof in the axial direction by restricting features. Finally, the assembled water cold plate is fixed by integral brazing.

It should be understood that the various components constituting the water cold plate may be made of copper, aluminum or alloy material, preferably aluminum, to achieve good heat dissipation. The heat dissipation fins 3 are preferably made of aluminum of series AA1XXX or 6XXX, and the cover plate 1 and the bottom plate 2 are preferably made of aluminum of series AA3XXX. The material for the cover 1 plate is preferably clad, most preferably on both sides, with a brazing filler metal, such as aluminum of series AA4XXX. The materials for the bottom plate 2 and for the fins 3 are preferably unclad. The thickness of the cover plate 1 and the bottom plate 2 may be 0.5-2 mm, and the wall thickness of the heat dissipation fins 3 may be 0.5-1 .5 mm. Under the premise of ensuring the overall rigidity requirement, the thickness of the cover plate 1 can be appropriately reduced so as to reduce the thermal resistance thereof to assist in heat dissipation.

After the water cold plate is installed in a battery module, a plurality of battery cells 6 of the battery module can be placed in the spaces between the plurality of heat dissipation fins 3, as shown in Fig. 7, so that the heat of the battery cells 6 may be transmitted to the liquid cooling medium in the heat dissipation flow channel via the heat dissipation fins 3. The liquid cooling medium herein includes cooling water, chilled water or coolant, and the like. In addition, some heat conductive members, such as pads and/or heat conductive adhesive indicated by numeral 7 in Fig. 7 may be provided in advance. Particularly, a heat conductive pad may be pasted on the bottom or side of the battery cells 6 or a heat conductive adhesive may be coated on the surface of the cover plate 1. In practical applications, the battery module combined with the water cold plate can also be provided with a fastening device on the sides to prevent from expanding toward the side normal direction during the battery assembly process. The flow direction of the cooling medium in the heat dissipation flow channel is shown by a broken line arrow in Fig. 8. Due to the structural design of the cover plate, the bottom plate and the heat dissipation fins, the heat dissipation flow channel is S-shaped, which increases the flow heat transfer coefficient, and the heat transferred through the heat dissipation fins can be fully exchanged in the heat dissipation flow channel to greatly improve the cooling efficiency.

The basic principle, main features and technical points of the present invention have been disclosed and described above, but it should be understood that without departing from the spirit and scope of the present invention, those skilled in the art can make various changes and improvements to the above disclosed technical features and embodiments, which all belong to the scope of the present invention. The description of the above embodiments is illustrative but not restrictive, and the scope of the present invention is defined by the claims.

Claims

1. A water cold plate for a battery module, wherein the water cold plate comprises a cover plate (1 ), a bottom plate (2) and a plurality of heat dissipation fins (3) which are integrally fixed, and a closed heat dissipation flow channel is formed between the cover plate (1 ) and the bottom plate (2), wherein an inlet end and an outlet end of the heat dissipation flow channel are respectively in fluid communication with a fluid inlet tube (4) and a fluid outlet tube (5) such that a liquid cooling medium flows in the heat dissipation flow channel, and the plurality of heat dissipation fins (3) are spaced apart from each other and perpendicularly inserted into the cover plate (1 ) to be in communication with the heat dissipation flow channel, and wherein a plurality of battery cells (6) of a battery module are capable of being placed in spaces between the plurality of heat dissipation fins (3), so that heat of the battery cells (6) is transmitted to the liquid cooling medium in the heat dissipation flow channel via the heat dissipation fins (3).

2. The water cold plate according to claim 1 , wherein the cover plate (1 ) is provided with a plurality of slits (1a) for inserting the plurality of heat dissipation fins (3), and each slit (1a) perpendicularly extends a portion from a side edge of the cover plate towards an opposite side edge, and the plurality of slits (1 a) extending along different side edges are staggered from each other.

3. The water cold plate according to any one of the claims 1-2, wherein the bottom plate is provided with a plurality of grooves (2a) in the position corresponding to the plurality of slits (1 a), and the heat dissipation fins (3) are restricted by the slits (1 a) and the grooves (2a).

4. The water cold plate according to any one of the claims 1-3, wherein an insertion edge of each heat dissipation fin is provided with an insertion section (3b) for inserting into the slit (1 a) and a contact section (3a) for contacting a surface of the cover plate (1 ), and the depth of the insertion section (3b) being inserted into the slit (1 a) is substantially equal to the height of the heat dissipation flow channel.

5. The water cold plate according to any one of the claims 1-4, wherein the contact section (3a) has a flanging edge for abutting against the surface of the cover plate.

6. The water cold plate according to any one of claims 1-5, wherein a flanging edge (1 b, 2b) is formed at a periphery of the cover plate and/or the bottom plate for restricting the cover plate and the bottom plate.

7. The water cold plate according to any one of claims 1-6, wherein a heat conductive member (7) is arranged between the battery cells (6) and also between the battery cells (6), the heat dissipation fins (3) and the cover plate (1 ).

8. The water cold plate according to any one of claims 1-7, wherein the inlet end and the outlet end of the heat dissipation flow channel are arranged on the cover plate (1 ) or the bottom plate (2).

9. The water cold plate according to any one of claims 1-8, wherein the liquid cooling medium includes cooling water, chilled water or coolant.

10. The water cold plate according to any one of claims 1-9, wherein the water cold plate is configured for the battery thermal management in an electric vehicle.