Thermal management method and thermal management system for battery pack, and vehicle

Abstract

The present application relates to the technical field of batteries. Provided are a thermal management method and thermal management system for a battery pack, and a vehicle. The thermal management method for a battery pack is used for the thermal management system for a battery pack. The thermal management system is configured to switch between a first circulation mode and a second circulation mode. The thermal management method for a battery pack comprises the following steps: determining that a battery pack has a cooling requirement; determining whether a thermal management system meets a mode switching condition; if the thermal management system does not meet the mode switching condition, controlling the thermal management system to operate in a first circulation mode or a second circulation mode; and if the thermal management system meets the mode switching condition, controlling the thermal management system to switch between the first circulation mode and the second circulation mode. The thermal management method for a battery pack of the present application reduces the number of times the thermal management system switches between a first circulation mode and a second circulation mode, thereby reducing the number of impacts on the internal structure of the thermal management system, which is conducive to prolonging the service life of the thermal management system.

Description

Battery pack thermal management methods, thermal management systems and vehicles

[0001] This application claims priority to Chinese Patent Application No. 202411501724.4, filed on October 25, 2024, entitled “Temperature Management Method, Thermal Management System and Vehicle for Battery Pack”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a thermal management method for a battery pack, a thermal management system, and a vehicle. Background Technology

[0003] A battery thermal management system can keep the battery within a suitable operating temperature range, maintaining its optimal operating condition and thus slowing down the degradation of battery charge, health, and capacity, thereby affecting the reliability and stability of the vehicle.

[0004] Existing battery thermal management systems include a battery pack and a cooling module. The battery pack has heat dissipation channels, and a drive pump within the cooling module drives coolant to flow along these channels, facilitating heat transfer between the battery pack and the coolant, thereby adjusting the overall temperature of the battery pack. The drive pump can either drive the coolant from one end of the heat dissipation channel to the other, or vice versa. To ensure a more uniform temperature distribution within the battery pack, the drive pump switches the coolant flow direction at regular intervals.

[0005] However, when switching the coolant flow direction, water hammer may occur, and devices such as heat dissipation channels and valves in the refrigeration module will be impacted. Frequent switching of coolant flow direction will affect the service life of the thermal management system. Summary of the Invention

[0006] The purpose of this application is to provide a thermal management method for a battery pack, a thermal management system, and a vehicle, in order to solve the problem that frequent switching of coolant flow in existing battery thermal management systems affects the service life of the thermal management system.

[0007] In a first aspect, this application discloses a thermal management method for a battery pack, which is used in a thermal management system for a battery pack. The thermal management system includes: a battery pack and a cooling module. The cooling module includes a first three-way valve, a second three-way valve, a drive pump, and a heat exchanger. The battery pack has an internal heat dissipation channel and a first outlet and a second outlet connected to the internal heat dissipation channel. The first three-way valve is connected to the first outlet through a first liquid inlet channel. The first three-way valve is connected to the second outlet through a second liquid inlet channel. The second three-way valve is connected to the second outlet through a first liquid outlet channel. The second three-way valve is connected to the first outlet through a second liquid outlet channel. The first end of the heat exchanger is connected to the first three-way valve. The second end of the heat exchanger is connected to the second three-way valve. The drive pump is configured to drive coolant to flow from the second end of the heat exchanger to the first end.

[0008] The thermal management system is configured to switch between a first circulation mode and a second circulation mode, wherein in the first circulation mode, the first three-way valve opens the first liquid inlet channel and the second three-way valve opens the first liquid outlet channel; in the second circulation mode, the first three-way valve opens the second liquid inlet channel and the second three-way valve opens the second liquid outlet channel.

[0009] Thermal management methods include the following steps:

[0010] It was determined that the battery pack required cooling.

[0011] Determine if the thermal management system meets the mode switching conditions:

[0012] If the condition is not met, the thermal management system will be controlled to operate in either the first or second cycle mode.

[0013] If the conditions are met, the thermal management system will switch between the first and second cycle modes.

[0014] In one possible implementation, the thermal management method for the battery pack provided in this application determines that the battery pack has cooling requirements, including:

[0015] Determine if the battery pack temperature has reached the second preset temperature value:

[0016] If so, then the battery pack has a cooling requirement;

[0017] If not, then it is determined that the battery pack has no cooling requirement.

[0018] In one possible implementation, the thermal management method for the battery pack provided in this application determines whether the thermal management system meets the mode switching conditions, including:

[0019] Determine if the battery pack is subjected to high-rate charge and discharge:

[0020] If not, then the thermal management system does not meet the mode switching conditions.

[0021] In one possible implementation, the thermal management method for the battery pack provided in this application, which determines whether the battery pack is undergoing high-rate charging and discharging, further includes:

[0022] If so, determine whether the temperature difference between the first flow port and the second flow port reaches the first preset temperature value:

[0023] If so, then the thermal management system meets the mode switching conditions;

[0024] If not, then the thermal management system does not meet the mode switching conditions.

[0025] In one possible implementation, the thermal management method for the battery pack provided in this application, which determines whether the battery pack is undergoing high-rate charging and discharging, includes:

[0026] Determine whether the battery pack's operating current exceeds the preset current value and reaches the first preset duration:

[0027] If so, then the battery pack is confirmed to be undergoing high-rate charging and discharging.

[0028] If not, then it is determined that the battery pack has not undergone high-rate charging and discharging.

[0029] In one possible implementation, the thermal management method for the battery pack provided in this application has a preset current value ranging from 150A to 200A; and / or,

[0030] The first preset duration ranges from 5 min to 20 min.

[0031] In one possible implementation, the thermal management method for the battery pack provided in this application, after determining that the battery pack has cooling requirements and before determining whether the thermal management system meets the mode switching conditions, further includes:

[0032] It was confirmed that the thermal management system did not report any faults.

[0033] In one possible implementation, the thermal management method for the battery pack provided in this application controls the thermal management system to switch between a first cycle mode and a second cycle mode, including:

[0034] The thermal management system alternates between the first and second cycle modes according to a preset cycle until the thermal management system meets the exit conditions.

[0035] In one possible implementation, the thermal management method for the battery pack provided in this application controls the thermal management system to alternately switch between a first cycle mode and a second cycle mode according to a preset period, including:

[0036] After one of the first and second loop patterns ends and before the other begins;

[0037] Control the drive pump to stop running for a second preset time.

[0038] In one possible implementation, the thermal management method for the battery pack provided in this application has a second preset duration ranging from 20s to 50s.

[0039] In one possible implementation, the thermal management method for the battery pack provided in this application includes the following exit conditions:

[0040] The temperature of the battery pack is determined to be lower than the third preset temperature value, and the third preset temperature is lower than the second preset temperature.

[0041] Secondly, this application discloses a thermal management system suitable for applying any of the above-mentioned thermal management methods. The thermal management system includes: a battery pack and a refrigeration module. The refrigeration module includes a first three-way valve, a second three-way valve, a drive pump, and a heat exchanger. The battery pack has an internal heat dissipation channel and a first outlet and a second outlet connected to the internal heat dissipation channel. The first three-way valve is connected to the first outlet through a first liquid inlet channel, the first three-way valve is connected to the second outlet through a second liquid inlet channel, the second three-way valve is connected to the second outlet through a first liquid outlet channel, and the second three-way valve is connected to the first outlet through a second liquid outlet channel. The first end of the heat exchanger is connected to the first three-way valve, and the second end of the heat exchanger is connected to the second three-way valve. The drive pump is configured to drive coolant to flow from the second end of the heat exchanger to the first end.

[0042] The thermal management system is configured to switch between a first circulation mode and a second circulation mode. In the first circulation mode, the first three-way valve opens the first liquid inlet channel and the second three-way valve opens the first liquid outlet channel. In the second circulation mode, the first three-way valve opens the second liquid inlet channel and the second three-way valve opens the second liquid outlet channel.

[0043] Thirdly, this application discloses a vehicle, including: the thermal management system of the second aspect.

[0044] Based on the above technical solutions, the thermal management method, thermal management system, and vehicle for the battery pack provided in this application include a battery pack and a cooling module. The cooling module includes a first three-way valve, a second three-way valve, and a drive pump. The battery pack has an internal heat dissipation channel and a first outlet and a second outlet communicating with the internal heat dissipation channel. The first three-way valve and the second three-way valve are both connected to the first outlet and the second outlet. By controlling the first three-way valve, the second three-way valve, and the drive pump, the thermal management system can switch between a first circulation mode and a second circulation mode. In the first circulation mode, coolant flows into the internal heat dissipation channel through the first outlet and flows out through the second outlet. In the second circulation mode, coolant flows into the internal heat dissipation channel through the second outlet and flows out through the first outlet. In existing technologies, once a thermal management system is started, it continuously switches between the first and second circulation modes. The flow direction of the coolant also changes continuously, impacting the first three-way valve, the second three-way valve, and the internal heat dissipation channels, thus affecting the service life of the thermal management system. The battery pack thermal management method provided in this application adds a mode switching condition. The specific steps are as follows: First, determine whether the battery pack has a cooling requirement; if so, determine whether the mode switching condition is met; if not, the thermal management system operates only in the first or second circulation mode; if so, the thermal management system switches between the first and second circulation modes. In this way, the thermal management system will only switch between the first and second circulation modes when the battery pack has a cooling requirement and the mode switching conditions are met, changing the flow direction of the coolant. When the switching conditions are not met, the cooling requirement of the battery pack can be met by continuously operating either the first or second circulation mode. This reduces the number of times the first and second circulation modes are switched while meeting the cooling requirement of the battery pack, thus reducing the switching frequency and minimizing the impact of the coolant on the first three-way valve, the second three-way valve, and the internal heat dissipation channels. This helps to improve the service life of the thermal management system and, in turn, improve the reliability and stability of the vehicle. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 is a schematic flowchart of the thermal management method for a battery pack provided in an embodiment of this application;

[0047] Figure 2 is a schematic flowchart of a thermal management method for a battery pack provided in another embodiment of this application;

[0048] Figure 3 is a schematic diagram of the structure of the thermal management system provided in an embodiment of this application.

[0049] Explanation of reference numerals in the attached drawings: 100-First three-way valve; 200-Second three-way valve; 300-Drive pump; 400-Heat exchanger; 500-Expansion tank; 600-Battery pack; 610-First inlet port; 611-First inlet channel; 612-First outlet channel; 620-Second inlet port; 621-Second inlet channel; 622-Second outlet channel; 700-Controller.

[0050] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0051] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0052] As shown in the background section, in existing technologies, a battery thermal management system includes a battery pack and a cooling module. The battery pack has heat dissipation channels, and a drive pump within the cooling module can drive coolant to flow along the heat dissipation channels, facilitating heat transfer between the battery pack and the coolant, thereby adjusting the overall temperature of the battery pack. The drive pump can drive the coolant from one end of the heat dissipation channel to the other, or vice versa. To ensure a more uniform temperature distribution inside the battery pack, the drive pump switches the direction of coolant flow at regular intervals.

[0053] However, when switching the coolant flow direction, water hammer may occur, and devices such as heat dissipation channels and valves in the refrigeration module will be impacted. Frequent switching of coolant flow direction will affect the service life of the thermal management system.

[0054] To address the aforementioned technical problems, this application provides a thermal management method for a battery pack, a thermal management system, and a vehicle. The thermal management system includes a battery pack and a cooling module. The cooling module includes a first three-way valve, a second three-way valve, and a drive pump. The battery pack has an internal heat dissipation channel and a first outlet and a second outlet communicating with the internal heat dissipation channel. The first three-way valve and the second three-way valve are both connected to the first outlet and the second outlet. By controlling the first three-way valve, the second three-way valve, and the drive pump, the thermal management system can switch between a first circulation mode and a second circulation mode. In the first circulation mode, coolant flows into the internal heat dissipation channel through the first outlet and flows out through the second outlet. In the second circulation mode, coolant flows into the internal heat dissipation channel through the second outlet and flows out through the first outlet.

[0055] In existing technologies, once a thermal management system is started, it continuously switches between the first and second circulation modes. The flow direction of the coolant also changes continuously, impacting the first three-way valve, the second three-way valve, and the internal heat dissipation channels, thus affecting the service life of the thermal management system. The battery pack thermal management method provided in this application adds a mode switching condition. The specific steps are as follows: First, determine whether the battery pack has a cooling requirement; if so, determine whether the mode switching condition is met; if not, the thermal management system operates only in the first or second circulation mode; if so, the thermal management system switches between the first and second circulation modes.

[0056] In this way, the thermal management system will only switch between the first and second circulation modes when the battery pack has a cooling requirement and the mode switching conditions are met, changing the flow direction of the coolant. When the switching conditions are not met, the cooling requirement of the battery pack can be met by continuously operating either the first or second circulation mode. This reduces the number of times the first and second circulation modes are switched while meeting the cooling requirement of the battery pack, thus reducing the switching frequency and minimizing the impact of the coolant on the first three-way valve, the second three-way valve, and the internal heat dissipation channels. This helps to improve the service life of the thermal management system and, in turn, improve the reliability and stability of the vehicle.

[0057] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings:

[0058] Referring to Figures 1 and 3, the thermal management method for a battery pack according to an embodiment of this application is used in the thermal management system of a battery pack 600. The thermal management system includes a battery pack 600 and a cooling module. The cooling module includes a first three-way valve 100, a second three-way valve 200, a drive pump 300, and a heat exchanger 400. The battery pack 600 has an internal heat dissipation channel and a first outlet 610 and a second outlet 620 communicating with the internal heat dissipation channel. The first three-way valve 100 and the first outlet 610 are connected by a first liquid inlet channel 611. The first three-way valve 100 is connected to the second inlet 620 through the second liquid inlet channel 621, the second three-way valve 200 is connected to the second inlet 620 through the first liquid outlet channel 612, the second three-way valve 200 is connected to the first inlet 610 through the second liquid outlet channel 622, the first end of the heat exchanger 400 is connected to the first three-way valve 100, the second end of the heat exchanger 400 is connected to the second three-way valve 200, and the drive pump 300 is configured to drive the coolant to flow from the second end to the first end of the heat exchanger 400.

[0059] The thermal management system is configured to switch between a first circulation mode and a second circulation mode. In the first circulation mode, the first three-way valve 100 opens the first liquid inlet channel 611 and the second three-way valve 200 opens the first liquid outlet channel 612. In the second circulation mode, the first three-way valve 100 opens the second liquid inlet channel 621 and the second three-way valve 200 opens the second liquid outlet channel 622.

[0060] Thermal management methods include the following steps:

[0061] S101. It is determined that battery pack 600 has a cooling requirement;

[0062] S102. Determine whether the thermal management system meets the mode switching conditions:

[0063] S103. If not satisfied, control the thermal management system to operate in either the first cycle mode or the second cycle mode.

[0064] S104. If satisfied, control the thermal management system to switch between the first cycle mode and the second cycle mode.

[0065] It should be understood that the step numbers in the various embodiments of this application do not constitute a limitation on the execution order, and the execution order of the steps in each embodiment should be determined according to its internal logic.

[0066] In this embodiment, the thermal management system includes a battery pack 600 and a refrigeration module. The battery pack 600 has an internal heat dissipation channel. The refrigeration module includes a first three-way valve 100, a second three-way valve 200, a heat exchanger 400, and a drive pump 300. The internal heat dissipation channel has a first outlet 610 and a second outlet 620. The first three-way valve 100 is connected to the first outlet 610 through a first liquid inlet channel 611 and to the second outlet 620 through a second liquid inlet channel 621. The second three-way valve 200 is connected to the second outlet 620 through a first liquid outlet channel 612 and to the first outlet 610 through a second liquid outlet channel 622. Therefore, the thermal management system can operate in two modes: a first circulation mode and a second circulation mode.

[0067] In the first circulation mode, the coolant flows sequentially through the first three-way valve 100, the first inlet channel 611, the first outlet 610, the internal heat dissipation channel, the second outlet 620, the first outlet channel 612, the second three-way valve 200, the drive pump 300, the heat exchanger 400, and the first three-way valve 100 to complete one circulation. In the second circulation mode, the coolant flows through the first three-way valve 100, the second inlet channel 621, the second outlet 620, the internal heat dissipation channel, the first outlet 610, the second outlet channel 622, the second three-way valve 200, the drive pump 300, the heat exchanger 400, and the first three-way valve 100 to complete one circulation. It can be observed that in the first circulation mode and the second circulation mode, the flow direction of the coolant driven by the drive pump 300 does not change. The switching between the first circulation mode and the second circulation mode is achieved by controlling the connection relationship between the first three-way valve 100 and the first inlet channel 611 and the second inlet channel 621, as well as the connection relationship between the second three-way valve 200 and the second inlet channel 621 and the second outlet channel 622, thereby changing the flow direction of the coolant in the internal heat dissipation channel of the battery pack 600.

[0068] When the thermal management system switches between the first and second circulation modes, the flow velocity and direction of the coolant in the internal heat dissipation channels suddenly change, generating a large impulse. This change is short-lived, resulting in a significant impact on the internal heat dissipation channels. The sudden change in the connection between the first three-way valve 100 and the second three-way valve 200 may also cause water hammer in the vicinity of these valves, impacting them. Therefore, when the thermal management system switches between the first and second circulation modes, the internal heat dissipation channels and the first and second three-way valves are subjected to significant impact. However, in existing technologies, once the cooling module of the thermal management system is activated, it switches between the first and second circulation modes at a specific frequency, causing continuous impact on the internal heat dissipation channels and the first and second three-way valves, thus affecting the service life of the thermal management system.

[0069] In this embodiment, the thermal management method for the battery pack incorporates a mode-switching condition, ensuring that the cooling module only switches to the cycle mode under certain circumstances after startup, thus reducing the number of impacts on the internal heat dissipation channels, the first three-way valve 100, and the second three-way valve 200. The specific steps are as follows: First, determine whether the battery pack 600 has a cooling requirement: if not, the cooling module is not started; if so, determine whether the mode-switching condition is met: if not, the thermal management system operates only in either the first cycle mode or the second cycle mode; if met, the thermal management system switches between the first cycle mode and the second cycle mode.

[0070] The conditions for mode switching are not limited in this embodiment. For example, since the main purpose of switching between the first and second cycle modes is to improve the temperature uniformity of the thermal management system and reduce the temperature difference between different parts of the battery pack 600, the mode switching condition can be set to start switching when the temperature difference between opposite sides of the battery pack 600 is greater than or equal to a first preset temperature value. When the temperature difference between opposite sides of the battery pack 600 is less than the first preset temperature value, the first or second cycle mode can be maintained, thus avoiding a large temperature difference. In this way, the temperature difference between the two sides of the battery pack 600 is kept within a certain range, ensuring the temperature uniformity of the thermal management system, while also reducing the frequency of switching between the first and second cycle modes and reducing the number of times the internal heat dissipation channels, the first three-way valve 100, and the second three-way valve 200 are subjected to impact.

[0071] Thus, the thermal management system only switches between the first and second circulation modes when the battery pack 600 has a cooling requirement and the mode switching conditions are met, changing the flow direction of the coolant. When the switching conditions are not met, the cooling requirement of the battery pack 600 can be met by continuously operating either the first or second circulation mode. This reduces the number of times the first and second circulation modes are switched while meeting the cooling requirement of the battery pack 600, thereby reducing the impact of the coolant on the first three-way valve 100, the second three-way valve 200, the drive pump 300, the internal heat dissipation channels, and other structures. This helps to improve the service life of the thermal management system, thereby improving the reliability and stability of the vehicle.

[0072] In some feasible implementations, referring to Figures 1, 2, and 3, the thermal management method for a battery pack according to an embodiment of this application determines that the battery pack 600 has a cooling requirement, including:

[0073] Determine if the temperature of battery pack 600 has reached the second preset temperature value:

[0074] If so, then it is confirmed that battery pack 600 has a cooling requirement;

[0075] If not, then it is confirmed that battery pack 600 has no cooling requirement.

[0076] In its implementation, multiple first temperature sensors are spaced apart on the battery pack 600 to monitor its temperature in real time. These first temperature sensors are communicatively connected to the controller 700 of the thermal management system. The sensors transmit the detected temperature data to the controller 700. When the temperature of the battery pack 600 is greater than or equal to a second preset temperature value, it indicates that the battery pack 600 requires cooling, and the next step is determined. If the temperature of the battery pack 600 is less than the second preset temperature value, it indicates that the battery pack 600 does not require cooling, and the process ends. In this way, the thermal management system can promptly determine when the battery pack 600 needs cooling and activate the cooling module, ensuring that the battery pack 600 operates within a suitable temperature range and guaranteeing its operational stability.

[0077] In some feasible implementations, referring to Figures 1, 2, and 3, the thermal management method for a battery pack according to an embodiment of this application, after determining that the battery pack 600 has a cooling requirement and before determining whether the thermal management system meets the mode switching conditions, further includes:

[0078] It was confirmed that the thermal management system did not report any faults.

[0079] It should be noted that each component of the thermal management system, including the first three-way valve 100, the second three-way valve 200, and the drive pump 300, is equipped with a corresponding fault detection unit. These fault detection units are communicatively connected to the controller 700 of the thermal management system. When a fault occurs in any part of the thermal management system, the controller 700 receives a fault signal and issues a fault indication. The specific method of fault indication is not limited in this embodiment; for example, the controller 700 is electrically connected to a buzzer or warning light, and an alarm signal is issued by activating the buzzer or warning light. After determining that the battery pack 600 has a cooling requirement, it is also necessary to confirm that the thermal management system has not malfunctioned before proceeding to the next step to ensure that the thermal management system can operate normally after starting cooling.

[0080] In some feasible implementations, referring to Figures 1, 2, and 3, the thermal management method for a battery pack according to an embodiment of this application determines whether the thermal management system meets the mode switching conditions, including:

[0081] Determine if the 600 battery pack is subjected to high-rate charge and discharge:

[0082] If not, then the thermal management system does not meet the mode switching conditions.

[0083] Understandably, the battery pack 600 typically only experiences high overall temperatures and significant temperature differences between different parts of the battery during high-rate charge and discharge. Therefore, determining whether the thermal management system meets the switching conditions specifically involves checking whether the battery pack 600 is undergoing high-rate charge and discharge. If the battery pack 600 is not undergoing high-rate charge and discharge, continuously running either the first or second cycle mode is sufficient to meet the cooling requirements. If the battery pack 600 is undergoing high-rate charge and discharge, further judgment can be made to confirm whether the switching conditions are met. In this way, when the battery pack 600 temperature is high and not undergoing high-rate charge and discharge, mode switching is not initiated, ensuring that the coolant flow direction is changed only when necessary, reducing the frequency of switching.

[0084] In some feasible implementations, referring to Figures 1, 2, and 3, the thermal management method for a battery pack according to an embodiment of this application determines whether the battery pack 600 is undergoing high-rate charge / discharge, including:

[0085] Determine whether the operating current of battery pack 600 is greater than the preset current value and whether the first preset duration has been reached:

[0086] If so, then confirm that the 600 battery pack is being charged and discharged at a high rate.

[0087] If not, then it is confirmed that the 600 battery pack has not undergone high-rate charging and discharging.

[0088] Specifically, whether the battery pack 600 is undergoing high-rate charging and discharging can be determined by detecting its operating current. Since the operating current of the battery pack 600 is not a constant value, it cannot be judged solely based on the operating current at a single moment. To ensure accuracy, the operating current of the battery pack 600 is monitored in real-time over a first preset time period. When the average operating current over the first preset time period is greater than a preset current value, it indicates that the battery pack 600 is undergoing high-rate charging and discharging, and the next step of judgment can be proceeded. When the average operating current over the first preset time period is less than or equal to the preset current value, it can be determined that the battery pack 600 is not undergoing high-rate charging and discharging. Thus, by monitoring the operating current and the duration of the monitoring, the accuracy of determining whether the battery pack 600 is undergoing high-rate charging and discharging can be improved.

[0089] In some feasible implementations, as shown in Figures 1, 2, and 3, the thermal management method for the battery pack according to embodiments of this application presets a current value ranging from 150A to 200A; and / or,

[0090] The first preset duration ranges from 5 min to 20 min.

[0091] In some embodiments, the preset current value ranges from 150A to 200A, and the first preset duration ranges from 5min to 20min. The specific values ​​of the preset current value and the first preset duration can be set according to the battery model and the working environment. This application embodiment does not limit these values.

[0092] In some feasible implementations, referring to Figures 1, 2, and 3, the thermal management method for a battery pack according to an embodiment of this application, in determining whether the battery pack 600 is undergoing high-rate charging and discharging, further includes:

[0093] If so, determine whether the temperature difference between the first flow port 610 and the second flow port 620 reaches the first preset temperature value:

[0094] If so, then the thermal management system meets the mode switching conditions;

[0095] If not, then the thermal management system does not meet the mode switching conditions.

[0096] In practical implementation, the battery pack 600 has at least one second temperature sensor installed at the first outlet 610 and the second outlet 620 of the internal heat dissipation channel. These sensors detect the temperature of the coolant flowing through the outlets and transmit the detected temperature to the controller 700. The controller 700 calculates the temperature difference between the coolant at the outlets 610 and 620. When the absolute value of the temperature difference is greater than or equal to a first preset temperature value, it indicates that the thermal management system needs to switch the coolant flow direction to make the temperature distribution of the battery pack 600 more uniform. When the absolute value of the temperature difference is less than the first preset temperature value, it indicates that the temperature distribution of the battery is relatively uniform, and only the first or second circulation mode needs to be activated to cool the battery pack 600. This further restricts the conditions for mode switching, reduces the frequency of switching, and helps to reduce the number of impacts on the first three-way valve 100, the second three-way valve 200, and the internal heat dissipation channel, thereby improving the service life of the thermal management system.

[0097] In some possible implementations, as shown in Figures 1, 2 and 3, the thermal management method for a battery pack according to an embodiment of this application controls the thermal management system to switch between a first cycle mode and a second cycle mode, including: controlling the thermal management system to alternately switch between the first cycle mode and the second cycle mode according to a preset cycle until the thermal management system meets the exit conditions.

[0098] It should be noted that when the thermal management system meets the conditions for mode switching, the thermal management system is controlled to alternately switch between the first circulation mode and the second circulation mode at a preset cycle. The preset cycle can be a fixed value or it can be set according to the absolute value of the temperature difference between the coolant at the first outlet 610 and the second outlet 620. The larger the temperature difference, the faster the switching frequency between the first circulation mode and the second circulation mode needs to be, i.e., the smaller the preset cycle. The specific value of the preset cycle is not limited in this embodiment.

[0099] For example, the thermal management system can be configured to detect the temperature difference between the coolant in the first outlet 610 and the second outlet 620 after each cycle switching. When the detected temperature difference is greater than or equal to the first temperature difference, the preset cycle is set to a first duration; when the detected temperature difference is less than the first temperature difference but greater than or equal to the second temperature difference, the preset cycle is set to a second duration; when the detected temperature difference is less than the second temperature difference, the preset cycle is set to a third duration, wherein the first temperature difference is greater than the second temperature difference, and the first duration is less than the second duration and less than the third duration. In this way, the switching frequency can be adjusted in real time according to the temperature difference of the coolant in the first outlet 610 and the second outlet 620, so that the cooling effect of the battery pack 600 is more uniform.

[0100] Furthermore, the exit condition in this application embodiment can be set to the temperature of the battery pack 600 being lower than the third preset temperature value, that is, the battery pack 600 no longer needs cooling and the thermal management system stops working. Alternatively, it can be set to determine again whether the thermal management system meets the mode switching condition, that is, the battery pack 600 still needs cooling, but the temperature difference is small, so the first cycle mode or the second cycle mode can be maintained without switching, further reducing the switching frequency. The specific setting of the exit condition is not limited in this application embodiment.

[0101] In some possible implementations, as shown in Figures 1, 2 and 3, the thermal management method for the battery pack of this application embodiment controls the thermal management system to alternately switch between a first cycle mode and a second cycle mode according to a preset period, including: after one of the first cycle mode and the second cycle mode ends and before the other begins; controlling the drive pump 300 to stop running for a second preset duration.

[0102] Understandably, when the thermal management system switches between the first and second circulation modes, after one of the two circulation modes ends, the drive pump 300 is first stopped for a second preset time before the other mode begins. This allows the coolant flow rate in the internal heat dissipation channels to first decrease to zero and then flow in the opposite direction. By extending the change time while keeping the velocity change (i.e., momentum change) constant, the impact force of the coolant on the first three-way valve 100, the second three-way valve 200, the internal heat dissipation channels, and other structures is reduced. This helps protect the internal structure of the thermal management system from damage and improves the service life of the thermal management system.

[0103] In some feasible implementations, as shown in Figures 1, 2 and 3, the thermal management method for the battery pack in this application embodiment has a second preset duration ranging from 20s to 50s.

[0104] Furthermore, the second preset duration is set between 20s and 50s. This ensures that the flow rate of the coolant in the internal heat dissipation channel is reduced to zero before switching begins, thereby reducing the impact of the coolant on the structure of the thermal management system. At the same time, the duration should not be too long to avoid affecting the cooling efficiency.

[0105] In some feasible implementations, as shown in Figures 1, 2 and 3, the thermal management method for the battery pack in this application includes an exit condition that includes: determining that the temperature of the battery pack 600 is lower than a third preset temperature value, and the third preset temperature is lower than a second preset temperature.

[0106] It is understandable that when the temperature of the battery pack 600 reaches the third preset temperature value, it means that the battery pack 600 no longer needs cooling and can be shut down. This ensures that the battery pack 600 always operates within the range of the third preset temperature value to the second preset temperature value, which helps to ensure the stability of the battery pack 600 and improve its performance.

[0107] Referring to Figure 3, this application embodiment also provides a thermal management system suitable for applying any of the above-described thermal management methods. The thermal management system includes a battery pack 600 and a refrigeration module. The refrigeration module includes a first three-way valve 100, a second three-way valve 200, a drive pump 300, and a heat exchanger 400. The battery pack 600 has an internal heat dissipation channel and a first outlet 610 and a second outlet 620 communicating with the internal heat dissipation channel. The first three-way valve 100 and the first outlet 610 are connected through a first liquid inlet channel 611. The first three-way valve 100 is connected to the second inlet 620 through the second liquid inlet channel 621, the second three-way valve 200 is connected to the second inlet 620 through the first liquid outlet channel 612, the second three-way valve 200 is connected to the first inlet 610 through the second liquid outlet channel 622, the first end of the heat exchanger 400 is connected to the first three-way valve 100, the second end of the heat exchanger 400 is connected to the second three-way valve 200, and the drive pump 300 is configured to drive the coolant to flow from the second end to the first end of the heat exchanger 400.

[0108] The thermal management system is configured to switch between a first circulation mode and a second circulation mode. In the first circulation mode, the first three-way valve 100 opens the first liquid inlet channel 611 and the second three-way valve 200 opens the first liquid outlet channel 612. In the second circulation mode, the first three-way valve 100 opens the second liquid inlet channel 621 and the second three-way valve 200 opens the second liquid outlet channel 622.

[0109] The working principle of the thermal management method has been explained in detail in the above embodiments, and will not be repeated here.

[0110] In this embodiment, the thermal management system includes a battery pack 600 and a refrigeration module. The battery pack 600 has an internal heat dissipation channel. The refrigeration module includes a first three-way valve 100, a second three-way valve 200, a heat exchanger 400, an expansion tank 500, and a drive pump 300. The internal heat dissipation channel has a first outlet 610 and a second outlet 620. The first three-way valve 100 is connected to the first outlet 610 through a first liquid inlet channel 611 and to the second outlet 620 through a second liquid inlet channel 621. The second three-way valve 200 is connected to the second outlet 620 through a first liquid outlet channel 612 and to the first outlet 610 through a second liquid outlet channel 622. Therefore, the thermal management system can operate in two modes: a first circulation mode and a second circulation mode.

[0111] In the first circulation mode, the coolant flows sequentially through the first three-way valve 100, the first inlet channel 611, the first outlet 610, the internal heat dissipation channel, the second outlet 620, the first outlet channel 612, the second three-way valve 200, the expansion tank 500, the drive pump 300, the heat exchanger 400, and the first three-way valve 100 to complete one circulation. In the second circulation mode, the coolant flows through the first three-way valve 100, the second inlet channel 621, the second outlet 620, the internal heat dissipation channel, the first outlet 610, the second outlet channel 622, the second three-way valve 200, the expansion tank 500, the drive pump 300, the heat exchanger 400, and the first three-way valve 100 to complete one circulation.

[0112] It can be observed that in both the first and second circulation modes, the flow direction of the coolant driven by the pump 300 remains unchanged. The switching between the first and second circulation modes is achieved by controlling the connection between the first three-way valve 100 and the first inlet channel 611 and the second inlet channel 621, as well as the connection between the second three-way valve 200 and the second inlet channel 621 and the second outlet channel 622. This changes the flow direction of the coolant within the internal heat dissipation channels of the battery pack 600. This ensures that in both modes, the coolant first passes through the heat exchanger 400 before entering the internal heat dissipation channels, and then passes through the expansion tank 500 before exiting the internal heat dissipation channels. This prevents the thermal management system from bursting due to excessive pressure, while also ensuring its cooling effect and facilitating the safe and stable operation of the thermal management system.

[0113] This application also provides a vehicle, including the aforementioned thermal management system.

[0114] The structure and working principle of the thermal management system have been described in detail in the above embodiments, and will not be repeated here.

[0115] In this embodiment of the application, by setting the above-mentioned thermal management system on the vehicle, the battery pack 600 can be cooled in a timely manner and the temperature uniformity of the battery pack 600 can be improved. This ensures that the battery pack 600 operates within a suitable temperature range, while also extending the service life of the thermal management system, which is conducive to ensuring the safe and stable use of the vehicle.

[0116] In summary, the battery pack thermal management method, thermal management system, and vehicle provided in this application embodiment include a battery pack 600 and a cooling module. The battery pack 600 has an internal heat dissipation channel. The cooling module includes a first three-way valve 100, a second three-way valve 200, and a drive pump 300. By controlling the connection between the first three-way valve 100 and the second three-way valve 200 and the first outlet 610 and the second outlet 620 of the internal heat dissipation channel, the flow direction of the coolant in the internal heat dissipation channel can be changed to achieve a uniform temperature effect. As shown in Figures 2 and 3, the specific steps of the thermal management method are as follows: First, determine if the temperature of the battery pack 600 reaches the second preset temperature value; second, determine if the thermal management system has not reported a fault; third, determine if the battery pack 600 is undergoing high-rate charging / discharging and if the temperature difference between the first flow port 610 and the second flow port 620 reaches the first preset temperature value. If not, the thermal management system operates in either the first or second cycle mode until the temperature of the battery pack 600 is lower than the third preset temperature value. If yes, a preset cycle is determined based on the temperature difference, and the thermal management system alternates between the first and second cycle modes according to the preset cycle until the temperature of the battery pack 600 is lower than the third preset temperature value; finally, exit the thermal management system.

[0117] In this way, the coolant flow direction is switched only when the battery pack 600 temperature is high and the temperature difference is large. While ensuring the cooling and temperature equalization effect of the thermal management system, the number of switching times is effectively reduced, thereby reducing the number of times the coolant impacts the first three-way valve 100 and the second three-way valve 200. This helps to improve the service life of the thermal management system and ensures that the battery pack 600 can operate safely and stably.

[0118] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0119] The devices or elements referred to in the embodiments of this application or implied herein must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of this application. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0120] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0121] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0122] The term "multiple" in this article refers to two or more. The term "and / or" in this article is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0123] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application.

[0124] It is understood that, in the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0125] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0126] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A thermal management method for a battery pack, used in the thermal management system of a battery pack (600), characterized in that, The thermal management system includes a battery pack (600) and a refrigeration module. The refrigeration module includes a first three-way valve (100), a second three-way valve (200), a drive pump (300), and a heat exchanger (400). The battery pack (600) has an internal heat dissipation channel and a first inlet (610) and a second inlet (620) communicating with the internal heat dissipation channel. The first three-way valve (100) is connected to the first inlet (610) through a first liquid inlet channel (611), and the first three-way valve (100) is connected to the second inlet (620) through a first liquid inlet channel (611). The two inlet channels (621) are connected, the second three-way valve (200) and the second outlet (620) are connected through the first outlet channel (612), the second three-way valve (200) and the first outlet (610) are connected through the second outlet channel (622), the first end of the heat exchanger (400) is connected to the first three-way valve (100), the second end of the heat exchanger (400) is connected to the second three-way valve (200), and the drive pump (300) is configured to drive the coolant to flow from the second end of the heat exchanger (400) to the first end; The thermal management system is configured to switch between a first circulation mode and a second circulation mode, wherein in the first circulation mode, the first three-way valve (100) opens the first liquid inlet channel (611) and the second three-way valve (200) opens the first liquid outlet channel (612); in the second circulation mode, the first three-way valve (100) opens the second liquid inlet channel (621) and the second three-way valve (200) opens the second liquid outlet channel (622). The thermal management method includes the following steps: It is determined that the battery pack (600) has a cooling requirement; Determine whether the thermal management system meets the mode switching conditions: If the condition is not met, the thermal management system is controlled to operate in either the first cycle mode or the second cycle mode. If the conditions are met, the thermal management system is controlled to switch between the first cycle mode and the second cycle mode.

2. The thermal management method for a battery pack according to claim 1, characterized in that, The determination that the battery pack (600) has a cooling requirement includes: Determine whether the temperature of the battery pack (600) has reached the second preset temperature value: If so, then it is determined that the battery pack (600) has a cooling requirement; If not, then it is determined that the battery pack (600) has no cooling requirement.

3. The thermal management method for a battery pack according to claim 1, characterized in that, Determining whether the thermal management system meets the mode switching conditions includes: Determine whether the battery pack (600) is subjected to high-rate charge and discharge: If not, then it is determined that the thermal management system does not meet the mode switching conditions.

4. The thermal management method for a battery pack according to claim 3, characterized in that, The step of determining whether the battery pack (600) is undergoing high-rate charging and discharging also includes: If so, determine whether the temperature difference between the first flow port (610) and the second flow port (620) reaches the first preset temperature value: If so, then the thermal management system is determined to meet the mode switching conditions; If not, then it is determined that the thermal management system does not meet the mode switching conditions.

5. The thermal management method for a battery pack according to claim 3, characterized in that, Determining whether the battery pack (600) is undergoing high-rate charge / discharge includes: Determine whether the operating current of the battery pack (600) is greater than a preset current value and reaches a first preset duration: If so, then the battery pack (600) is determined to be subjected to high-rate charge and discharge; If not, it is determined that the battery pack (600) has not undergone high-rate charging and discharging.

6. The thermal management method for a battery pack according to claim 5, characterized in that, The preset current value ranges from 150A to 200A; and / or, The first preset duration ranges from 5 min to 20 min.

7. The thermal management method for a battery pack according to claim 1, characterized in that, After determining that the battery pack (600) has a cooling requirement, and before determining whether the thermal management system meets the mode switching conditions, the method further includes: It was determined that the thermal management system did not report any faults.

8. The thermal management method for a battery pack according to claim 1, characterized in that, The control of the thermal management system to switch between the first circulation mode and the second circulation mode includes: The thermal management system is controlled to alternate between the first cycle mode and the second cycle mode according to a preset cycle until the thermal management system meets the exit condition.

9. The thermal management method for a battery pack according to claim 8, characterized in that, The control of the thermal management system to alternate between the first circulation mode and the second circulation mode according to a preset cycle includes: After one of the first loop pattern and the second loop pattern ends, and before the other begins; Control the drive pump (300) to stop running for a second preset time.

10. The thermal management method for a battery pack according to claim 9, characterized in that, The second preset duration ranges from 20s to 50s.

11. The thermal management method for a battery pack according to claim 8, characterized in that, The exit conditions include: The temperature of the battery pack (600) is determined to be lower than a third preset temperature value, which is lower than a second preset temperature.

12. A thermal management system suitable for applying the thermal management method according to any one of claims 1-11, characterized in that, The thermal management system includes a battery pack (600) and a refrigeration module. The refrigeration module includes a first three-way valve (100), a second three-way valve (200), a drive pump (300), and a heat exchanger (400). The battery pack (600) has an internal heat dissipation channel and a first inlet (610) and a second inlet (620) communicating with the internal heat dissipation channel. The first three-way valve (100) is connected to the first inlet (610) through a first liquid inlet channel (611), and the first three-way valve (100) is connected to the second inlet (620) through a first liquid inlet channel (611). The two inlet channels (621) are connected, the second three-way valve (200) and the second outlet (620) are connected through the first outlet channel (612), the second three-way valve (200) and the first outlet (610) are connected through the second outlet channel (622), the first end of the heat exchanger (400) is connected to the first three-way valve (100), the second end of the heat exchanger (400) is connected to the second three-way valve (200), and the drive pump (300) is configured to drive the coolant to flow from the second end of the heat exchanger (400) to the first end; The thermal management system is configured to switch between a first circulation mode and a second circulation mode, wherein in the first circulation mode, the first three-way valve (100) opens the first liquid inlet channel (611) and the second three-way valve (200) opens the first liquid outlet channel (612); in the second circulation mode, the first three-way valve (100) opens the second liquid inlet channel (621) and the second three-way valve (200) opens the second liquid outlet channel (622).

13. A vehicle, characterized in that, include: The thermal management system according to claim 12.

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