WO2024032036A1

WO2024032036A1 - Thermal management device, power battery assembly and control method therefor

Info

Publication number: WO2024032036A1
Application number: PCT/CN2023/091329
Authority: WO
Inventors: 卢军; 董昊旻; 李黎黎; 曹云飞; 南海; 刘茹; 岳振东; 兰超
Original assignee: 中国第一汽车股份有限公司
Priority date: 2022-08-09
Filing date: 2023-04-27
Publication date: 2024-02-15
Also published as: CN115020868A; CN115020868B

Abstract

Disclosed in the present application are a thermal management device, a power battery assembly and a control method therefor. The power battery assembly comprises a battery module, and further comprises a heat exchanger, wherein the heat exchanger is arranged on at least one side surface of the battery module, the heat exchanger is provided with a closed cavity for accommodating refrigerant, a flow channel structure is arranged in the closed cavity, and a heater is arranged on an outer side wall surface of the closed cavity. In the embodiments of the present application, the heat exchanger is arranged on at least one side surface of the battery module, and the heater is arranged on the outer side wall surface of the closed cavity of the heat exchanger, and the heat exchanger is heated by means of the heater, such that heat exchange between the heat exchanger and the battery module is accelerated, thereby reducing heat unevenness on a surface of the battery module, and thus improving the energy efficiency of the battery assembly.

Description

A thermal management device, power battery assembly and control method thereof

Technical field

The present application relates to the technical field of electric vehicle power battery assemblies, specifically, to a thermal management device, a power battery assembly and a control method thereof. This application requests the priority of the patent application submitted to the China State Intellectual Property Office on August 9, 2022, with the application number 202210947978.3 and the invention title "A thermal management device, a power battery assembly and a control method thereof".

Background technique

At present, due to the continued shortage of energy, serious environmental pollution and other issues, and under the dual influence of national regulations and environmental factors, it has become an inevitable trend to vigorously develop new energy vehicles. The power battery system of new energy vehicles mainly consists of battery modules, battery cases, pipelines, and circuits. The power battery system is a key component of electric vehicles. Its safety, reliability and durability are crucial and determine the performance of the entire vehicle.

At present, the main driving force of electric vehicles is provided by the battery pack composed of single cells, and the temperature and temperature uniformity have a great impact on the capacity, life and other performance of the battery pack. When the power battery is running at high power, the battery generates a large amount of heat. If it cannot be dissipated in time, the temperature of the battery will rise, which can easily cause thermal runaway and cause safety accidents. At the same time, at high temperatures, the temperature unevenness of the power battery increases. Large, further increasing safety risks. In order to extend battery life and avoid thermal safety accidents, a reasonable battery thermal management system must be designed to ensure that the battery operates at an appropriate temperature and at the same time improve the thermal uniformity of the battery module.

In recent years, the development and production of battery thermal management systems has attracted the attention of many electric vehicle manufacturers and battery manufacturers. However, there are still problems with poor thermal management performance and the inability to ensure temperature consistency between and within battery cells.

Application content

In view of this, this application aims to provide a thermal management device, a power battery and a control method for a power battery to solve the problem of poor thermal management performance in the prior art and the inability to ensure that the temperatures between and within the battery cells are consistent. Sexual technical issues.

In a first aspect, embodiments of the present application provide a power battery assembly, which includes a battery module and a heat exchanger. The heat exchanger is disposed on at least one side of the battery module. The heat exchange device There is a closed cavity for accommodating refrigerant, a flow channel structure is provided in the closed cavity, and a heater is provided on the outer wall of the closed cavity.

In an exemplary embodiment, the closed cavity at least includes an upper plate and a lower plate, and the upper plate and the lower plate are connected by at least one support column.

In an exemplary embodiment, a plurality of the support columns are evenly disposed between the upper plate and the lower plate.

In an exemplary embodiment, the refrigerant is a phase change material.

In an exemplary embodiment, the flow channel structure is a labyrinth structure or a symmetrical structure.

In a second aspect, embodiments of the present application also provide a thermal management device for a vehicle, which includes a control device and the power battery assembly described in any of the above technical solutions.

In a third aspect, embodiments of the present application further provide a vehicle, which includes the thermal management device described in any of the above technical solutions.

In a fourth aspect, embodiments of the present application also provide a control method for a power battery assembly. The power battery assembly is the power battery assembly described in any of the above technical solutions. The control method includes:

Obtain the maximum temperature difference of the battery module within the first predetermined time period; control the operation of the heater based on the maximum temperature difference.

In an exemplary embodiment, obtaining the maximum temperature difference of the battery module within the first predetermined time period includes:

Obtain the temperature value of the battery module at each sampling time point within the first predetermined time period; obtain the highest temperature value and the maximum temperature value of the battery module within the first predetermined time period based on the temperature value Minimum temperature value; determine the maximum temperature difference of the battery module based on the maximum temperature value and the minimum temperature value.

In an exemplary embodiment, controlling the operation of the heater based on the maximum temperature difference includes:

When the maximum temperature difference is less than or equal to the first temperature difference threshold, the heater is controlled not to work; when the maximum temperature difference is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, the heater is controlled to not work. The heater intermittently heats according to a predetermined period within a second predetermined time period; when the maximum temperature difference is greater than the second temperature difference threshold, the heater is controlled to continue heating within a third predetermined time period; wherein, The second temperature difference threshold is greater than the first temperature difference threshold.

In the embodiment of the present application, a heat exchanger is provided on at least one side of the battery module, and a heater is provided on the outer wall of the closed cavity of the heat exchanger. The heat exchanger is heated through the heater. The wall surface is heated, thereby improving heat exchange between the heat exchanger and the battery module, thereby reducing thermal unevenness on the surface of the battery module and improving the energy efficiency of the battery assembly.

In order to make the above-mentioned objects, features and advantages of the present application more obvious and understandable, preferred embodiments are given below and described in detail with reference to the attached drawings.

Description of drawings

In the drawings, which are not necessarily to scale, the same reference numbers may describe similar components in the different views. The same reference number with a letter suffix or different letter suffixes may refer to different instances of similar components. The drawings illustrate various embodiments generally by way of example and not limitation, and together with the description and claims serve to explain the disclosed embodiments. Where appropriate, the same reference numbers will be used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the apparatus or method. The drawings described here are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the attached picture:

Figure 1 is a schematic structural diagram of a power battery assembly for an electric vehicle provided by this application;

Figure 2 is a schematic structural diagram of a heat exchanger for a power battery assembly provided by this application;

Figure 3 is a schematic three-dimensional structural diagram of the heat exchanger used in the power battery assembly provided by this application;

Figure 4 is a perspective view of a heat exchanger for a power battery assembly provided by this application;

Figure 5 is a side view of the heat exchanger used in the power battery assembly provided by this application;

Figure 6 is a schematic structural diagram of a battery module used in a power battery assembly provided by this application;

Figure 7 is a control flow chart of the power battery assembly provided by this application;

Figure 8 is a flowchart of the steps provided by this application for obtaining the maximum temperature difference of the battery module within the first predetermined time period;

Figure 9 is a flow chart of steps for controlling the operation of the heater based on the maximum temperature difference provided by this application.

Among them, the above-mentioned drawings include the following reference signs:

1-battery module; 2-lower frame; 3-heat exchanger; 301-heater; 302-upper plate; 303-lower plate; 304-support column; 305-flow channel structure; 4-liquid cooling plate.

Detailed ways

Below, specific embodiments of the present application will be described in detail with reference to the accompanying drawings, but shall not be used as a limitation of the present application.

It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be viewed as limiting, but merely as examples of embodiments. Other modifications within the scope and spirit of this application will occur to those skilled in the art.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the general description of the application given above and the detailed description of the embodiments given below, serve to explain the application. principle.

These and other features of the present application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples with reference to the accompanying drawings.

It is further to be understood that, although the present application has been described with reference to a few specific examples, those skilled in the art will be able to undoubtedly implement many other equivalent forms of the present application, which have the characteristics as claimed and therefore all lie within the scope hereof. within a limited scope of protection.

The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

Specific embodiments of the present application are hereinafter described with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present application, which may be implemented in various ways. Well-known and/or repeated functions and structures have not been described in detail to avoid obscuring the application with unnecessary or redundant detail. Therefore, specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims, teaching one skilled in the art to variously utilize the present invention in substantially any suitable detailed structure. Apply.

It should be noted that the terms used in the description and claims of this application and the above-mentioned drawings "First", "second", etc. are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "include" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus. This specification may use the phrases "in one embodiment,""in another embodiment,""in yet another embodiment," or "in further embodiments," which may refer to the same thing in accordance with the present application. or one or more of the different embodiments.

The present application will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example 1

The first aspect of this application provides a power battery assembly. The power battery assembly here is one of the core components of new energy vehicles. The performance and service life of the power battery directly affect the performance and cost of the vehicle. When the power battery is running at high power, the battery generates a large amount of heat. If it cannot be dissipated in time, the temperature of the battery will rise, which can easily cause thermal runaway and cause safety accidents. At high temperatures, the temperature unevenness of the power battery increases. This further increases security risks. The purpose of the embodiments of the present application is to reduce the temperature unevenness of the power battery by thermally managing the temperature of the power battery assembly.

To this end, the power battery assembly involved in the embodiment of the present application can realize natural heat dissipation of the battery thermal management system through natural convection. As shown in Figure 1, Figure 1 shows a schematic structural diagram of a power battery assembly for an electric vehicle in an embodiment of the present application. The power battery assembly includes a battery module 1 and a lower frame 2. The lower frame 2 is The bottom of the frame 2 is provided with a liquid cooling plate 4 for cooling the battery module. The battery module 1 is disposed on the liquid cooling plate 4 to achieve heat exchange with the liquid cooling plate 4 . The power battery assembly also includes a heat exchanger 3. The heat exchanger 3 is provided on at least one side of the battery module 1. The heat exchanger 3 has a closed cavity for containing refrigerant. A flow channel structure 305 is provided in the closed cavity, and a heater 301 is provided on the outer wall of the closed cavity. The heater is used to heat the refrigerant in the closed cavity. heating.

Figures 2, 3, 4, and 5 respectively show a schematic structural diagram of a heat exchanger for a power battery assembly in an embodiment of the present application. As shown in the figure, the heat exchanger 3 includes a A closed cavity that accommodates refrigerant. The closed cavity at least includes an upper plate 302 and a lower plate 303. The upper plate 302 and the lower plate 303 are connected by at least one support column 304, so that the upper plate 302 and the lower plate 303 can be connected. The support between the plate 302 and the lower plate 303.

Furthermore, there may be a plurality of support columns 304 . When there are a plurality of support columns 304 , the plurality of support columns 304 may be evenly disposed between the upper plate 302 and the lower plate 303 . The material of the support includes but is not limited to aluminum alloy, titanium alloy, copper alloy, etc., so that the heat exchange between the upper plate 302 and the lower plate 303 can be accelerated through the support column 304.

In one embodiment, reinforcing ribs may also be provided between the upper plate 302 and the lower plate 303, and the flow channel structure 305 for the circulation of the refrigerant is formed between the reinforcing ribs, so that The reinforcing ribs can not only enhance the strength of the cavity, but also serve as a separation structure for the flow channel, making the overall structure of the heat exchanger 3 simpler and easier to process and install.

Specifically, the flow channel structure 305 can be a labyrinth structure or a symmetrical structure, wherein the flow channel cross section can be any one of circular, oval, rectangular, square, D-shaped, and flat. The flow channel structure enables the refrigerant to be evenly distributed in the cavity of the heat exchanger, so that the heat transferred from the heater can be evenly transferred to the contact surface between the heat exchanger 3 and the battery module 1 .

As shown in Figure 6, when there are multiple battery modules 1, the heat exchanger 3 is provided on the side of each battery module 1, so that the heat exchanger 3 is heated to balance the The temperature of the battery module.

In order to further improve the cooling effect of the power battery pack, the liquid cooling plate 4 and the heat exchanger 3 can be made of alloy materials with good heat conduction effects. The alloy materials include but are not limited to aluminum alloy, titanium Alloys, copper alloys, etc.

In one embodiment, the refrigerant uses phase change materials. Specifically, the phase change material can be an organic phase change material (such as alcohol) or an inorganic phase change material, and can be materials with high thermal conductivity such as expanded graphite, carbon nanotubes, graphene, and ordinary organic phase change materials (such as paraffin wax). ,fat Fatty acid) composite phase change material or microcapsule phase change material.

The power battery assembly provided by this application is provided with a heat exchanger on at least one side of the battery module, and is provided with a heater on the outer wall of the closed cavity of the heat exchanger. The wall surface of the heat exchanger is heated, thereby improving heat exchange between the heat exchanger and the battery module, thereby reducing thermal unevenness on the surface of the battery module and improving the energy efficiency of the battery assembly.

Example 2

A second aspect of the application also provides a thermal management device for a vehicle, which includes a control device and the power battery assembly described in any of the above embodiments.

Wherein, the power battery assembly includes a battery module, and also includes a heat exchanger. The heat exchanger is arranged on at least one side of the battery module. The heat exchanger has a closed cavity for containing refrigerant. body, a flow channel structure is provided in the closed cavity, and a heater is provided on the outer wall of the closed cavity.

Example 3

A third aspect of the present application also provides a vehicle, which includes the thermal management device described in any of the above embodiments. The vehicle here includes but is not limited to pure electric vehicles and hybrid vehicles.

Example 4

The fourth aspect of this application also provides a control method for a power battery assembly. The power battery assembly is the power battery assembly described in any of the above technical solutions. Figure 7 shows the power battery assembly described in this application. The step flow chart of the control method is as shown in the figure. The control method specifically includes:

S101. Obtain the maximum temperature difference of the battery module within the first predetermined time period.

Since batteries have different heat dissipation effects during use, the temperatures at various locations of the battery module 1 are also different. In this step, the maximum temperature of the battery module 1 within the first predetermined time period is obtained. Temperature difference, as shown in Figure 8, obtaining the maximum temperature difference of the battery module 1 within the first predetermined time period includes the following steps:

S201: Obtain the temperature value of the battery module at each sampling time point within the first predetermined time period.

In this step, the temperature value of the battery module 1 at each sampling time point is obtained within the first predetermined time period, where the sampling points include the upper surface, bottom surface, and side surface of the battery module 1 The temperature at different points and the temperature inside the battery module 1. Specifically, by arranging temperature sensors on the upper surface, bottom surface, and side surfaces of the battery module 1 and inside the battery module, the temperatures at different points on the upper surface, bottom surface, and side surfaces of the battery module 1 and the corresponding temperature are obtained. Describe the temperature inside the battery module 1.

S202: Obtain the highest temperature value and the lowest temperature value of the battery module within the first predetermined time period based on the temperature value.

After completing the above step S201, in this step, the highest temperature and the lowest temperature of the battery module within the first predetermined time period are obtained based on the temperature value. Specifically, after completing the temperature sampling of the battery module 1, the highest temperature and the lowest temperature are selected from the temperature values, thereby obtaining the highest temperature value and the lowest temperature value.

S203. Determine the maximum temperature difference of the battery module based on the maximum temperature value and the minimum temperature value.

After completing the above step S202, in the step, the maximum temperature difference of the battery module is determined based on the maximum temperature value and the minimum temperature value.

S102, control the operation of the heater based on the maximum temperature difference.

After completing the above step S101, in this step, the operation of the heater is controlled based on the maximum temperature difference. Specifically, the battery management system BMS determines whether the power battery assembly needs to be controlled based on the collected temperature. Figure 9 shows a schematic diagram of the steps for controlling the operation of the heater based on the maximum temperature difference. As shown in the figure, control The heater work specifically includes:

S301: When the maximum temperature difference is less than or equal to the first temperature difference threshold, control the heater not to work.

In this step, when the maximum temperature difference is less than or equal to the first temperature difference threshold, the regulating valve is controlled to close, wherein the first temperature difference threshold can be selected as 5. When the maximum temperature difference is less than or equal to 5, it means that at this time The thermal uniformity of the battery module 1 in the power battery assembly is good. At this time, the heater does not work and the battery module 1 is not heated.

S302: When the maximum temperature difference is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, control the heater to intermittently heat according to a predetermined period within a second predetermined time period.

In this step, when the maximum temperature difference is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, the heater is controlled to intermittently heat according to a predetermined period within a second predetermined time period. Wherein, the second temperature difference threshold can be selected as 8, and the second predetermined time period can be selected as 3 minutes, that is, when the maximum temperature difference is greater than 5 and less than 8, it means that the battery module in the power battery assembly at this time 1 has poor thermal uniformity. At this time, the battery management system sends a signal instruction to control the heater to perform intermittent heating. For example, the heating cycle is to heat for 10 seconds and pause for 10 seconds. The heater 301 exchanges heat with the heater 301. The heat exchanger 3 is heated, so that the battery module 1 and the heat exchanger 3 exchange heat, thereby achieving the effect of balancing the surface temperature of the battery module 1 . After controlling the heater 301 to perform intermittent heating for 3 minutes, the maximum temperature difference is collected again to check the thermal uniformity of the battery module.

S303: When the maximum temperature difference is greater than the second temperature difference threshold, control the heater to continue heating within a third predetermined time period.

In this step, when the maximum temperature difference is greater than the second temperature difference threshold, the regulating valve is controlled to remain open. Specifically, when the maximum temperature difference is greater than 8, it means that the thermal uniformity of the battery module 1 in the power battery assembly is very poor at this time and is in a runaway mode. At this time, the battery management system sends a signal instruction to control the heater to continue heating, and the heat exchanger 3 is heated by the heater 301, so that the battery module 1 and the heat exchanger 3 Heat exchange is performed to achieve the effect of balancing the surface temperature of the battery module 1 . After controlling the heater 301 to continue heating for 5 minutes, collect the temperature of the battery module 1 again to obtain the maximum temperature difference and check the thermal uniformity of the battery module 1 .

In the control method of the power battery assembly provided by the present application, a heat exchanger can be provided on at least one side of the battery module, and a heater can be provided on the outer wall of the closed cavity of the heat exchanger. The heater is controlled to heat the wall surface of the heat exchanger, thereby improving the heat exchange between the heat exchanger and the battery module, thereby reducing the thermal unevenness on the surface of the battery module and improving the overall battery performance. energy efficiency.

The above serial numbers of the embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

In the above-mentioned embodiments of the present application, each embodiment is described with its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

For the convenience of description, spatially relative terms can be used here, such as "on...", "on...", "on the upper surface of...", "above", etc., to describe what is shown in the figure. The spatial relationship between one device or feature and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a feature in the figure is turned upside down, then one feature described as "above" or "on top of" other features or features would then be oriented "below" or "below" the other features or features. under other devices or structures". Thus, the exemplary term "over" may include both orientations "above" and "below." The device may be otherwise oriented, rotated 90 degrees or at other orientations and the spatially relative descriptors used herein interpreted accordingly.

In addition to the above, it should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or structures described in conjunction with this embodiment. Features are included in at least one embodiment generally described herein. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure or characteristic is described in connection with any embodiment, it is intended that implementation of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present application.

In the above embodiments, each embodiment is described with its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

The above descriptions are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims

A power battery assembly, which includes a battery module, is characterized in that it also includes a heat exchanger, the heat exchanger is arranged on at least one side of the battery module, and the heat exchanger has a structure for accommodating refrigerant A closed cavity is provided with a flow channel structure in the closed cavity, and a heater is provided on the outer wall of the closed cavity.
The power battery assembly according to claim 1, wherein the closed cavity includes at least an upper plate and a lower plate, and the upper plate and the lower plate are connected by at least one support column.
The power battery assembly according to claim 2, characterized in that a plurality of the support pillars are evenly arranged between the upper plate and the lower plate.
The power battery assembly according to claim 1, wherein the refrigerant is a phase change material.
The power battery assembly according to claim 1, characterized in that the flow channel structure is a labyrinth structure or a symmetrical structure.
A thermal management device for a vehicle, which includes a control device, and is characterized in that it also includes the power battery assembly according to any one of claims 1-5.
A vehicle, characterized in that it includes the thermal management device according to claim 6.
A control method for a power battery assembly, the power battery assembly being the power battery assembly according to any one of claims 1 to 5, characterized in that the control method includes:

Obtain the maximum temperature difference of the battery module within the first predetermined time period;

The heater operation is controlled based on the maximum temperature difference.
The control method according to claim 8, characterized in that said obtaining the maximum temperature difference of the battery module within the first predetermined time period includes:

Obtain the temperature value of the battery module at each sampling time point within the first predetermined time period;

Obtain the highest temperature value and the lowest temperature value of the battery module within the first predetermined time period based on the temperature value;

The maximum temperature difference of the battery module is determined based on the maximum temperature value and the minimum temperature value.
The control method according to claim 8, wherein the controlling the operation of the heater based on the maximum temperature difference includes:

When the maximum temperature difference is less than or equal to the first temperature difference threshold, control the heater not to work;

When the maximum temperature difference is greater than the first temperature difference threshold and less than or equal to the second temperature difference threshold, control the heater to intermittently heat according to a predetermined period within a second predetermined time period;

When the maximum temperature difference is greater than the second temperature difference threshold, control the heater to continue heating within a third predetermined time period;

Wherein, the second temperature difference threshold is greater than the first temperature difference threshold.