Thermal management method and thermal management system of battery pack and vehicle

Abstract

The invention provides a thermal management method and system of a battery pack and a vehicle, and relates to the technical field of batteries. The thermal management method of the battery pack is used for a thermal management system of the battery pack, the thermal management system is configured to be switched between a first circulation mode and a second circulation mode, and the thermal management method of the battery pack comprises the following steps: determining that the battery pack has a refrigeration demand; determining whether the thermal management system meets a mode switching condition or not; if not, controlling the thermal management system to operate in a first circulation mode or a second circulation mode; and if yes, the heat management system is controlled to be switched between the first circulation mode and the second circulation mode. According to the thermal management method of the battery pack, the switching frequency of the thermal management system between the first circulation mode and the second circulation mode is reduced, so that the impact frequency of the internal structure of the thermal management system is reduced, and the service life of the thermal management system is prolonged.

Description

Technical Field

[0001] The present 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 Art

[0002] The battery's thermal management system can keep the battery within a suitable operating temperature range and keep the battery in good working condition, thereby delaying the battery's charge, health and capacity decay, which in turn affects the vehicle's reliability and stability.

[0003] The existing battery thermal management system includes a battery pack and a refrigeration module. The battery pack is provided with a heat dissipation channel. The driving pump in the refrigeration module can drive the coolant to flow along the heat dissipation channel to transfer heat between the battery pack and the coolant, thereby adjusting the overall temperature of the battery pack. The driving pump can drive the coolant to flow from the first end of the heat dissipation channel to the second end, or from the second end of the heat dissipation channel to the first end. In order to make the temperature distribution inside the battery pack more uniform, the driving pump switches the flow direction of the coolant every certain period of time.

[0004] However, when switching the coolant flow direction, water hammer may occur, and the heat dissipation flow channel, valves in the refrigeration module and other devices will be impacted. Frequent switching of the coolant flow direction will affect the service life of the thermal management system. Summary of the invention

[0005] The present application provides a thermal management method for a battery pack, a thermal management system and a vehicle, so as to solve the problem that frequent switching of the flow direction of the coolant in the existing battery thermal management system will affect the service life of the thermal management system.

[0006] In a first aspect, the present application provides a thermal management method for a battery pack, which is used for a thermal management system of a battery pack, wherein the thermal management system comprises: a battery pack and a refrigeration module, wherein the refrigeration module comprises a first three-way valve, a second three-way valve, a driving pump and a heat exchanger, wherein the battery pack has an internal heat dissipation channel and a first flow port and a second flow port connected to the internal heat dissipation channel, wherein the first three-way valve is connected to the first flow port through a first liquid inlet channel, the first three-way valve is connected to the second flow port through a second liquid inlet channel, the second three-way valve is connected to the second flow port through a first liquid outlet channel, the second three-way valve is connected to the first flow port 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, and the driving pump is configured to drive the coolant to flow from the second end of the heat exchanger to the first end;

[0007] 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 conducts the first liquid inlet channel and the second three-way valve conducts the first liquid outlet channel, and in the second circulation mode, the first three-way valve conducts the second liquid inlet channel and the second three-way valve conducts the second liquid outlet channel;

[0008] The thermal management method includes the following steps:

[0009] Determine that the battery pack has cooling requirements;

[0010] Determine whether the thermal management system meets the mode switching conditions:

[0011] If not, the thermal management system is controlled to operate in the first cycle mode or the second cycle mode;

[0012] If the conditions are met, the thermal management system is controlled to switch between the first cycle mode and the second cycle mode.

[0013] In one possible implementation, the thermal management method for a battery pack provided in the present application determines that the battery pack has a cooling requirement, including:

[0014] Determine whether the temperature of the battery pack reaches a second preset temperature value:

[0015] If so, it is determined that the battery pack has a cooling requirement;

[0016] If not, it is determined that the battery pack has no cooling requirement.

[0017] In one possible implementation, the thermal management method of the battery pack provided in the present application determines whether the thermal management system meets the mode switching condition, including:

[0018] Determine whether the battery pack is charged and discharged at a high rate:

[0019] If not, it is determined that the thermal management system does not meet the mode switching condition.

[0020] In one possible implementation, the thermal management method of the battery pack provided in the present application determines whether the battery pack is to be charged and discharged at a high rate, and further includes:

[0021] If so, determine whether the temperature difference between the first flow opening and the second flow opening reaches a first preset temperature value:

[0022] If so, determining that the thermal management system meets the mode switching condition;

[0023] If not, it is determined that the thermal management system does not meet the mode switching condition.

[0024] In one possible implementation, the thermal management method of a battery pack provided in the present application determines whether the battery pack is to be charged and discharged at a high rate, including:

[0025] Determine whether the operating current of the battery pack is greater than a preset current value and reaches a first preset time:

[0026] If so, it is determined that the battery pack is charged and discharged at a high rate;

[0027] If not, it is determined that the battery pack is not charged or discharged at a high rate.

[0028] In a possible implementation, in the thermal management method for a battery pack provided in the present application, the preset current value is in the range of 150A-200A; and / or,

[0029] The first preset duration ranges from 5 minutes to 20 minutes.

[0030] In one possible implementation, the thermal management method of the battery pack provided in the present application, after determining that the battery pack has a cooling requirement and before determining whether the thermal management system meets the mode switching condition, further includes:

[0031] Make sure the thermal management system has not reported a fault.

[0032] In a possible implementation, the thermal management method of a battery pack provided in the present application controls the thermal management system to switch between a first cycle mode and a second cycle mode, including:

[0033] The thermal management system is controlled to switch alternately between the first cycle mode and the second cycle mode according to a preset period until the thermal management system meets an exit condition.

[0034] In one possible implementation, the thermal management method of the battery pack provided in the present application controls the thermal management system to switch alternately between the first cycle mode and the second cycle mode according to a preset period, including:

[0035] After one of the first cycle mode and the second cycle mode ends and before the other begins;

[0036] The driving pump is controlled to stop running for a second preset time period.

[0037] In one possible implementation, in the thermal management method for a battery pack provided in the present application, the second preset time length has a value range of 20s-50s.

[0038] In one possible implementation, the thermal management method for a battery pack provided in the present application, the exit conditions include:

[0039] It is determined that the temperature of the battery pack is lower than a third preset temperature value, and the third preset temperature is lower than the second preset temperature.

[0040] In a second aspect, the present application provides a thermal management system suitable for applying any of the above thermal management methods, the thermal management system comprising: a battery pack and a refrigeration module, the refrigeration module comprising a first three-way valve, a second three-way valve, a drive pump and a heat exchanger, the battery pack having an internal heat dissipation channel and a first flow port and a second flow port connected to the internal heat dissipation channel, the first three-way valve being connected to the first flow port through a first liquid inlet channel, the first three-way valve being connected to the second flow port through a second liquid inlet channel, the second three-way valve being connected to the second flow port through a first liquid outlet channel, the second three-way valve being connected to the first flow port through a second liquid outlet channel, the first end of the heat exchanger being connected to the first three-way valve, the second end of the heat exchanger being connected to the second three-way valve, the drive pump being configured to drive the coolant to flow from the second end of the heat exchanger to the first end;

[0041] 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 connects to the first liquid inlet channel and the second three-way valve connects to the first liquid outlet channel, and in the second circulation mode, the first three-way valve connects to the second liquid inlet channel and the second three-way valve connects to the second liquid outlet channel.

[0042] In a third aspect, the present application provides a vehicle, comprising: the thermal management system of the second aspect.

[0043] The present application provides a thermal management method, a thermal management system and a vehicle for a battery pack, wherein the thermal management system includes a battery pack and a refrigeration module, wherein the refrigeration module includes a first three-way valve, a second three-way valve and a driving pump, wherein the battery pack has an internal heat dissipation channel and a first flow port and a second flow port connected to the internal heat dissipation channel, wherein the first three-way valve and the second three-way valve are both connected to the first flow port and the second flow port. By controlling the first three-way valve, the second three-way valve and the driving pump, the thermal management system can be switched between a first circulation mode and a second circulation mode. In the first circulation mode, the coolant flows into the internal heat dissipation channel through the first flow port and flows out through the second flow port. In the second circulation mode, the coolant flows into the internal heat dissipation channel through the second flow port and flows out through the first flow port. In the prior art, once the thermal management system is started, it will continuously switch between the first circulation mode and the second circulation mode, and the flow direction of the coolant will also continuously change, impacting the first three-way valve, the second three-way valve and the internal heat dissipation channel, affecting the service life of the thermal management system. The battery pack thermal management method provided in the present application adds a mode switching condition, and the specific steps are: first, determine whether the battery pack has a cooling demand; if so, then determine whether the mode switching conditions are met: if not, the thermal management system only operates in the first circulation mode or the second circulation mode; if satisfied, the thermal management system switches between the first circulation mode and the second circulation mode. In this way, the thermal management system will switch between the first circulation mode and the second circulation mode only when the battery pack has a cooling demand and the mode switching conditions are met, changing the flow direction of the coolant. When the switching conditions are not met, the cooling demand of the battery pack can be met by continuously running in one of the first circulation mode and the second circulation mode. While meeting the cooling demand of the battery pack, the number of switching between the first circulation mode and the second circulation mode is reduced, and the switching frequency is reduced, thereby reducing the impact of the coolant on the first three-way valve, the second three-way valve, the internal heat dissipation channel and other structures, which is beneficial to increasing the service life of the thermal management system, and thus improving the reliability and stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a thermal management method for a battery pack provided in an embodiment of the present application;

[0046] Figure 2 A schematic flow chart of a thermal management method for a battery pack provided in another embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of the thermal management system provided in an embodiment of the present application.

[0048] Description of reference numerals:

[0049] 100 - first three-way valve;

[0050] 200-second three-way valve;

[0051] 300-driving pump;

[0052] 400-heat exchanger;

[0053] 500-Expansion kettle;

[0054] 600-battery pack;

[0055] 610-first flow opening; 611-first liquid inlet channel; 612-first liquid outlet channel;

[0056] 620-second flow port; 621-second liquid inlet channel; 622-second liquid outlet channel;

[0057] 700-Controller.

[0058] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0059] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0060] As shown in the background technology, in the prior art, the battery thermal management system includes a battery pack and a refrigeration module. The battery pack is provided with a heat dissipation channel. The driving pump in the refrigeration module can drive the coolant to flow along the heat dissipation channel to transfer heat between the battery pack and the coolant, thereby adjusting the overall temperature of the battery pack. The driving pump can drive the coolant to flow from the first end of the heat dissipation channel to the second end, or from the second end of the heat dissipation channel to the first end. In order to make the temperature distribution inside the battery pack more uniform, the driving pump switches the flow direction of the coolant once every certain period of time.

[0061] However, when switching the coolant flow direction, water hammer may occur, and the heat dissipation flow channel, valves in the refrigeration module and other devices will be impacted. Frequent switching of the coolant flow direction will affect the service life of the thermal management system.

[0062] In view of the above technical problems, the embodiments of the present application provide 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 refrigeration module. The refrigeration module includes a first three-way valve, a second three-way valve and a driving pump. The battery pack has an internal heat dissipation channel and a first flow port and a second flow port connected to the internal heat dissipation channel. The first three-way valve and the second three-way valve are both connected to the first flow port and the second flow port. By controlling the first three-way valve, the second three-way valve and the driving pump, the thermal management system can be switched between a first circulation mode and a second circulation mode. In the first circulation mode, the coolant flows into the internal heat dissipation channel through the first flow port and flows out through the second flow port. In the second circulation mode, the coolant flows into the internal heat dissipation channel through the second flow port and flows out through the first flow port.

[0063] In the prior art, once the thermal management system is started, it will continuously switch between the first circulation mode and the second circulation mode, and the flow direction of the coolant will also continuously change, impacting the first three-way valve, the second three-way valve and the internal heat dissipation channel, affecting the service life of the thermal management system. The battery pack thermal management method provided in the present application adds a mode switching condition, and the specific steps are: first, determine whether the battery pack has a cooling demand; if so, then determine whether the mode switching conditions are met: if not, the thermal management system only operates in the first circulation mode or the second circulation mode; if satisfied, the thermal management system switches between the first circulation mode and the second circulation mode.

[0064] In this way, the thermal management system will switch between the first circulation mode and the second circulation mode only when the battery pack has a cooling demand and the mode switching conditions are met, changing the flow direction of the coolant. When the switching conditions are not met, the cooling demand of the battery pack can be met by continuously running in one of the first circulation mode and the second circulation mode. While meeting the cooling demand of the battery pack, the number of switching between the first circulation mode and the second circulation mode is reduced, and the switching frequency is reduced, thereby reducing the impact of the coolant on the first three-way valve, the second three-way valve, the internal heat dissipation channel and other structures, which is beneficial to increasing the service life of the thermal management system, and thus improving the reliability and stability of the vehicle.

[0065] The following specific embodiments are used to describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings:

[0066] See also Figure 1 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application is used for the thermal management system of the battery pack 600, the thermal management system includes: the battery pack 600 and the refrigeration module, the refrigeration module includes the first three-way valve 100, the second three-way valve 200, the drive pump 300 and the heat exchanger 400, the battery pack 600 has an internal heat dissipation flow channel and a first flow port 610 and a second flow port 620 connected to the internal heat dissipation flow channel, the first three-way valve 100 is connected to the first flow port 610 through a first liquid inlet channel 611, The first three-way valve 100 is connected to the second flow port 620 through the second liquid inlet channel 621, the second three-way valve 200 is connected to the second flow port 620 through the first liquid outlet channel 612, the second three-way valve 200 is connected to the first flow port 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 of the heat exchanger 400 to the first end.

[0067] 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 connects to the first liquid inlet channel 611, and the second three-way valve 200 connects to the first liquid outlet channel 612, and in the second circulation mode, the first three-way valve 100 connects to the second liquid inlet channel 621, and the second three-way valve 200 connects to the second liquid outlet channel 622.

[0068] The thermal management method includes the following steps:

[0069] S101, determining that the battery pack 600 has a cooling requirement;

[0070] S102, determining whether the thermal management system meets the mode switching condition:

[0071] S103: If not, control the thermal management system to operate in the first cycle mode or the second cycle mode;

[0072] S104: If the conditions are met, control the thermal management system to switch between the first cycle mode and the second cycle mode.

[0073] It should be understood that the step numbers in the various embodiments of the present 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.

[0074] In an embodiment of the present application, 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 flow port 610 and a second flow port 620. The first three-way valve 100 is connected to the first flow port 610 through a first liquid inlet channel 611, and is connected to the second flow port 620 through a second liquid inlet channel 621. The second three-way valve 200 is connected to the second flow port 620 through a first liquid outlet channel 612, and is connected to the first flow port 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.

[0075] In the first circulation mode, the coolant flows through the first three-way valve 100, the first liquid inlet channel 611, the first flow port 610, the internal heat dissipation channel, the second flow port 620, the first liquid outlet channel 612, the second three-way valve 200, the drive pump 300, the heat exchanger 400 and the first three-way valve 100 in sequence to complete one circulation; in the second circulation mode, the coolant flows through the first three-way valve 100, the second liquid inlet channel 621, the second flow port 620, the internal heat dissipation channel, the first flow port 610, the second liquid outlet channel 622, the second three-way valve 200, the drive pump 300, the heat exchanger 400 and the first three-way valve 100 once to complete one circulation. It can be found that in the first circulation mode and the second circulation mode, the flow direction of the coolant driven by the driving pump 300 does not change. Only by controlling and changing the connection relationship between the first three-way valve 100 and the first liquid inlet channel 611 and the second liquid inlet channel 621 and the second three-way valve 200 and the second liquid inlet channel 621 and the second liquid outlet channel 622, the switching between the first circulation mode and the second circulation mode is achieved, thereby changing the flow direction of the coolant in the internal heat dissipation channel of the battery pack 600.

[0076] When the thermal management system switches between the first circulation mode and the second circulation mode, the speed direction of the coolant flowing in the internal heat dissipation channel suddenly changes, thereby generating a large impulse, and the change time is short, so the impulse generated on the internal heat dissipation channel is large, and the first three-way valve 100 and the second three-way valve 200 suddenly change the connection relationship, which may also cause the coolant near the first three-way valve 100 and the second three-way valve 200 to have a water hammer phenomenon, impacting the first three-way valve 100 and the second three-way valve 200, so that when the thermal management system switches between the first circulation mode and the second circulation mode, the internal heat dissipation channel, the first three-way valve 100 and the second three-way valve 200 will be greatly impacted. However, in the prior art, once the refrigeration module of the thermal management system is started, it switches between the first circulation mode and the second circulation mode at a specific frequency, causing the internal heat dissipation channel, the first three-way valve 100 and the second three-way valve 200 to be continuously impacted, thereby affecting the service life of the thermal management system.

[0077] In the embodiment of the present application, the thermal management method of the battery pack adds a mode switching condition, so that the circulation mode will only be switched in some cases after the refrigeration module is started, reducing the number of times the internal heat dissipation channel, the first three-way valve 100 and the second three-way valve 200 are impacted. The specific steps are: first determine whether the battery pack 600 has a refrigeration demand: if not, do not start the refrigeration module; if so, determine whether the mode switching condition is met: if not, the thermal management system only operates in the first circulation mode or the second circulation mode; if satisfied, the thermal management system switches between the first circulation mode and the second circulation mode.

[0078] Among them, the conditions for mode switching are not limited in the embodiments of the present application. For example, since the main purpose of switching back and forth between the first cycle mode and the second cycle mode is to make the thermal management system have a better temperature equalization effect and reduce the temperature difference between the various parts of the battery pack 600, the mode switching condition can be set to start switching when the temperature difference between the two opposite sides of the battery pack 600 is greater than or equal to the first preset temperature value. When the temperature difference between the two opposite sides of the battery pack 600 is less than the first preset temperature value, the first cycle mode or the second cycle mode can be maintained for circulation, and no large temperature difference will be generated. In this way, it is ensured that the temperature difference on both sides of the battery pack 600 is controlled within a certain range, ensuring the temperature equalization effect of the thermal management system, and the frequency of switching between the first cycle mode and the second cycle mode can be reduced, reducing the number of times the internal heat dissipation channel, the first three-way valve 100 and the second three-way valve 200 are impacted.

[0079] In this way, the thermal management system will switch between the first circulation mode and the second circulation mode only when the battery pack 600 has a cooling demand and the mode switching conditions are met, thereby changing the flow direction of the coolant. When the switching conditions are not met, the cooling demand of the battery pack 600 can be met by continuously running in one of the first circulation mode and the second circulation mode. While meeting the cooling demand of the battery pack 600, the number of switching between the first circulation mode and the second circulation mode is reduced, 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 channel and other structures, which is beneficial to improving the service life of the thermal management system, and thus improving the reliability and stability of the vehicle.

[0080] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application determines that the battery pack 600 has a cooling demand, including:

[0081] Determine whether the temperature of the battery pack 600 reaches a second preset temperature value:

[0082] If yes, it is determined that the battery pack 600 has a cooling requirement;

[0083] If not, it is determined that the battery pack 600 has no cooling requirement.

[0084] In the specific implementation, multiple first temperature sensors are arranged at intervals on the battery pack 600 to detect the temperature of the battery pack 600 in real time. The first temperature sensors are connected to the controller 700 of the thermal management system in communication. The first temperature sensors transmit the detected temperature to the controller 700. When the temperature of the battery pack 600 is greater than or equal to the second preset temperature value, it proves that the battery pack 600 has a cooling demand, and the next step of judgment is performed. If the temperature of the battery pack 600 is less than the second preset temperature value, it proves that the battery pack 600 has no cooling demand, and the process ends. In this way, the thermal management system can make a timely judgment and turn on the cooling module when the battery pack 600 needs cooling, ensuring that the battery pack 600 can work within a suitable temperature range and ensuring the stability of the battery pack 600.

[0085] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack in the embodiment of the present application, after determining that the battery pack 600 has a cooling demand and before determining whether the thermal management system meets the mode switching condition, further includes:

[0086] Make sure the thermal management system has not reported a fault.

[0087] It should be noted that the first three-way valve 100, the second three-way valve 200, the drive pump 300 and other parts of the thermal management system are all provided with corresponding fault detection units, and the fault detection unit is connected to the controller 700 of the thermal management system in communication. When a part of the thermal management system fails, the controller 700 will receive a fault signal and issue a fault prompt, wherein the specific method of the fault prompt is not limited in the embodiment of the present application. For example, the controller 700 is electrically connected to a buzzer or a warning light, and an alarm signal is issued by starting the buzzer or the warning light. After determining that the battery pack 600 has a cooling demand, it is also necessary to determine that the thermal management system has no fault before the next step of judgment can be made to ensure that the thermal management system can operate normally after starting cooling.

[0088] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application determines whether the thermal management system meets the mode switching condition, including:

[0089] Determine whether the battery pack 600 is charged or discharged at a high rate:

[0090] If not, it is determined that the thermal management system does not meet the mode switching condition.

[0091] It is understandable that the battery pack 600 generally has a high overall temperature and a large temperature difference between the various parts of the battery only when it is charged and discharged at a high rate. Therefore, determining whether the thermal management system meets the switching conditions is specifically to determine whether the battery pack 600 is charged and discharged at a high rate. If the battery pack 600 is not charged and discharged at a high rate, then continuously running one of the first cycle mode and the second cycle mode can meet the cooling demand. If the battery pack 600 is charged and discharged at a high rate, the next step of judgment can be performed to further confirm whether the switching conditions are met. In this way, when the temperature of the battery pack 600 is high and it is not charged and discharged at a high rate, the mode switching is not performed, ensuring that the coolant flow direction is changed only when necessary, reducing the number of switching times.

[0092] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application determines whether the battery pack 600 is charged and discharged at a high rate, including:

[0093] Determine whether the operating current of the battery pack 600 is greater than a preset current value and reaches a first preset time length:

[0094] If yes, it is determined that the battery pack 600 is charged and discharged at a high rate;

[0095] If not, it is determined that the battery pack 600 is not subjected to high-rate charge and discharge.

[0096] Specifically, it is possible to determine whether the battery pack 600 is being charged or discharged at a high rate by detecting the working current of the battery pack 600. Since the working current of the battery pack 600 is not a constant value, it cannot be determined only by the working current at a certain moment. To ensure the accuracy of the judgment, the working current of the battery pack 600 is detected in real time within the first preset time period. When the average value of the working current within the first preset time period is greater than the preset current value, it proves that the battery pack 600 is being charged or discharged at a high rate and the next step of judgment can be made. When the average value of the working current within 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 being charged or discharged at a high rate. In this way, the accuracy of the judgment of the high-rate charging or discharging of the battery pack 600 can be improved by the working current and time period.

[0097] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, in the thermal management method of the battery pack of the embodiment of the present application, the preset current value ranges from 150A to 200A; and / or,

[0098] The first preset duration ranges from 5 minutes to 20 minutes.

[0099] In some embodiments, the preset current value ranges from 150A to 200A, and the first preset time ranges from 5min to 20min. The specific values ​​of the preset current value and the first preset time can be set according to the battery model and working environment, and the embodiments of the present application do not limit this.

[0100] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application determines whether the battery pack 600 is charged and discharged at a high rate, and also includes:

[0101] If yes, it is determined whether the temperature difference between the first through-flow opening 610 and the second through-flow opening 620 reaches a first preset temperature value:

[0102] If so, determining that the thermal management system meets the mode switching condition;

[0103] If not, it is determined that the thermal management system does not meet the mode switching condition.

[0104] In a specific implementation, the battery pack 600 is provided with at least one second temperature sensor at the first flow opening 610 and the second flow opening 620 of the internal heat dissipation flow channel, respectively, for detecting the temperature of the coolant flowing through the first flow opening 610 and the second flow opening 620, and transmitting the detected temperature to the controller 700, and the controller 700 calculates the temperature difference of the coolant at the first flow opening 610 and the second flow opening 620. When the absolute value of the temperature difference is greater than or equal to the first preset temperature value, it proves that the thermal management system needs to switch the flow direction of the coolant to make the temperature distribution of each part of the battery pack 600 more uniform. When the absolute value of the temperature difference is less than the first preset temperature value, it proves that the temperature distribution of each part of the current battery is relatively uniform, and it is only necessary to turn on the first circulation mode or the second circulation mode to cool the battery pack 600. This further limits the conditions for mode switching, reduces the frequency of switching, and is conducive to reducing the number of times the first three-way valve 100, the second three-way valve 200 and the internal heat dissipation flow channel are impacted, thereby improving the service life of the thermal management system.

[0105] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack in an embodiment of the present 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 switch alternately between the first cycle mode and the second cycle mode according to a preset period until the thermal management system meets an exit condition.

[0106] 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 period, wherein the preset period can be a fixed value or can be set according to the absolute value of the temperature difference between the coolant in the first flow port 610 and the second flow port 620. The larger the temperature difference, the faster the frequency of switching between the first circulation mode and the second circulation mode, that is, the smaller the preset period. The specific value of the preset period is not limited in the embodiments of the present application.

[0107] Exemplarily, the thermal management system can be configured to detect the temperature difference between the coolant in the first flow port 610 and the second flow port 620 after each cycle switching, and when the detected temperature difference is greater than or equal to the first temperature difference, the preset period is set to the first duration; when the detected temperature difference is less than the first temperature difference and greater than or equal to the second temperature difference, the preset period is set to the second duration; when the detected temperature difference is less than the second temperature difference, the preset period is set to the 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 between the coolant in the first flow port 610 and the second flow port 620, so that the cooling effect of the battery pack 600 is more uniform.

[0108] In addition, the exit condition in the embodiment of the present application can be set to that the temperature of the battery pack 600 is lower than the third preset temperature value, that is, the battery pack 600 no longer needs to be refrigerated and the thermal management system stops working. It can also be set to again determine whether the thermal management system meets the conditions for mode switching, that is, the battery pack 600 still needs to be refrigerated, but the temperature difference is small. Therefore, it is sufficient to maintain the first cycle mode or the second cycle mode without switching again, thereby further reducing the switching frequency. The specific setting of the exit condition is not limited in the embodiment of the present application.

[0109] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack in an embodiment of the present application controls the thermal management system to switch alternately between the first cycle mode and the 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 starts; controlling the drive pump 300 to stop running for a second preset time.

[0110] It can be understood that when the thermal management system switches between the first circulation mode and the second circulation mode, after one of the first circulation mode and the second circulation mode ends, the drive pump 300 is first controlled to stop running for the second preset time period, and then the other one is started. In this way, the flow rate of the coolant in the internal heat dissipation channel can be reduced to zero first and then flow in the opposite direction. When the speed change, that is, the momentum change, remains unchanged, the change time is extended, thereby reducing the impact of the coolant on the first three-way valve 100, the second three-way valve 200, the internal heat dissipation channel and other structures, which is beneficial to protect the internal structure of the thermal management system from damage and increase the service life of the thermal management system.

[0111] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, in the thermal management method of the battery pack in the embodiment of the present application, the value range of the second preset time length is 20s-50s.

[0112] Furthermore, the second preset time length ranges from 20s to 50s, which can ensure that the flow rate of the coolant in the internal heat dissipation channel drops to zero before switching, thereby reducing the impact of the coolant on the various structures of the thermal management system. At the same time, the time should not be too long to avoid affecting the cooling efficiency.

[0113] In some possible implementations, see Figure 1 , Figure 2 and Figure 3 As shown, the thermal management method of the battery pack of the embodiment of the present application, the exit condition includes: determining that the temperature of the battery pack 600 is lower than the third preset temperature value, and the third preset temperature is lower than the second preset temperature.

[0114] It can be understood that when the temperature of the battery pack 600 reaches the third preset temperature value, it proves that the battery pack 600 no longer needs to be refrigerated and can be exited. In this way, the battery pack 600 always operates within the range of the third preset temperature value to the second preset temperature value, which is beneficial to ensuring the working stability of the battery pack 600 and improving the working performance of the battery pack 600.

[0115] See also Figure 3 As shown, the embodiment of the present application further provides a thermal management system suitable for applying any of the above thermal management methods, the thermal management system comprising: a battery pack 600 and a refrigeration module, the refrigeration module comprising 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 flow port 610 and a second flow port 620 communicating with the internal heat dissipation channel, the first three-way valve 100 is communicated with the first flow port 610 through a first liquid inlet channel 611, The first three-way valve 100 is in communication with the second flow port 620 via the second liquid inlet channel 621, the second three-way valve 200 is in communication with the second flow port 620 via the first liquid outlet channel 612, the second three-way valve 200 is in communication with the first flow port 610 via the second liquid outlet channel 622, the first end of the heat exchanger 400 is in communication with the first three-way valve 100, the second end of the heat exchanger 400 is in communication with the second three-way valve 200, and the driving pump 300 is configured to drive the coolant to flow from the second end to the first end of the heat exchanger 400;

[0116] 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 connects to the first liquid inlet channel 611, and the second three-way valve 200 connects to the first liquid outlet channel 612, and in the second circulation mode, the first three-way valve 100 connects to the second liquid inlet channel 621, and the second three-way valve 200 connects to the second liquid outlet channel 622.

[0117] The working principle of the thermal management method has been described in detail in the above embodiments and will not be described in detail here.

[0118] In an embodiment of the present application, 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 kettle 500 and a drive pump 300. The internal heat dissipation channel has a first flow port 610 and a second flow port 620. The first three-way valve 100 is connected to the first flow port 610 through a first liquid inlet channel 611, and is connected to the second flow port 620 through a second liquid inlet channel 621. The second three-way valve 200 is connected to the second flow port 620 through a first liquid outlet channel 612, and is connected to the first flow port 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.

[0119] In the first circulation mode, the coolant flows through the first three-way valve 100, the first liquid inlet channel 611, the first flow port 610, the internal heat dissipation channel, the second flow port 620, the first liquid outlet channel 612, the second three-way valve 200, the expansion kettle 500, the drive pump 300, the heat exchanger 400 and the first three-way valve 100 in sequence to complete one circulation; in the second circulation mode, the coolant flows through the first three-way valve 100, the second liquid inlet channel 621, the second flow port 620, the internal heat dissipation channel, the first flow port 610, the second liquid outlet channel 622, the second three-way valve 200, the expansion kettle 500, the drive pump 300, the heat exchanger 400 and the first three-way valve 100 once to complete one circulation.

[0120] It can be found that in the first circulation mode and the second circulation mode, the flow direction of the coolant driven by the driving pump 300 does not change. Only by controlling and changing the connection relationship between the first three-way valve 100 and the first liquid inlet channel 611 and the second liquid inlet channel 621 and the second three-way valve 200 and the second liquid inlet channel 621 and the second liquid outlet channel 622, the switching between the first circulation mode and the second circulation mode is realized, and the flow direction of the coolant in the internal heat dissipation channel of the battery pack 600 is changed. In both modes, the coolant first passes through the heat exchanger 400 and then enters the internal heat dissipation channel. When flowing out of the internal heat dissipation channel, it first passes through the expansion kettle 500 and then passes through the water pump, ensuring that the thermal management system will not cause a burst pipe due to excessive pressure, and at the same time, its cooling effect can be guaranteed, which is conducive to the safe and stable operation of the thermal management system.

[0121] An embodiment of the present application also provides a vehicle, including: the above-mentioned thermal management system.

[0122] Among them, the structure and working principle of the thermal management system are described in detail in the above embodiments, and will not be repeated here.

[0123] In the embodiment of the present application, by arranging the above-mentioned thermal management system on the vehicle, the battery pack 600 can be cooled in time, and the temperature equalization effect of the battery pack 600 can be improved. While ensuring that the battery pack 600 operates within a suitable temperature range, the service life of the thermal management system is improved, which is beneficial to ensuring the safe and stable use of the vehicle.

[0124] In summary, the thermal management method, thermal management system and vehicle of the battery pack provided by the embodiment of the present application, 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 and a driving pump 300, and the flow direction of the coolant in the internal heat dissipation channel can be changed by controlling the connection relationship between the first three-way valve 100 and the second three-way valve 200 and the first flow port 610 and the second flow port 620 of the internal heat dissipation channel to achieve a uniform temperature effect. Figure 2 and Figure 3 As shown, the specific steps of the thermal management method are as follows: determine that the temperature of the battery pack 600 reaches a second preset temperature value; determine that the thermal management system has not reported a fault; determine whether the battery pack 600 is charged and discharged at a large rate and the temperature difference between the first flow port 610 and the second flow port 620 reaches a first preset temperature value: if not, the thermal management system operates in the first cycle mode or the second cycle mode until the temperature of the battery pack 600 is lower than the third preset temperature value; if so, determine a preset period based on the temperature difference, and the thermal management system alternately switches between the first cycle mode and the second cycle mode according to the preset period until the temperature of the battery pack 600 is lower than the third preset temperature value; exit the thermal management system.

[0125] In this way, the flow direction of the coolant is switched only when the temperature of the battery pack 600 is high and the temperature difference is large. While ensuring the cooling and temperature equalization effects of the thermal management system, the number of switches is effectively reduced, thereby reducing the number of impacts of the coolant on the first three-way valve 100 and the second three-way valve 200, which is beneficial to improving the service life of the thermal management system and ensuring that the battery pack 600 can operate safely and stably.

[0126] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0127] In the embodiments of the present application, the devices or elements referred to or implied must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0128] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0129] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or apparatus.

[0130] The term "plurality" in this article refers to two or more than two. The term "and / or" in this article is just a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0131] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0132] It can be understood that in the embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean 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 the present application.

[0133] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0134] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A thermal management method for a battery pack, used in a thermal management system of a battery pack (600), characterized in that: The thermal management system comprises: a battery pack (600) and a refrigeration module, the refrigeration module comprising 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) having an internal heat dissipation channel and a first flow port (610) and a second flow port (620) communicating with the internal heat dissipation channel, the first three-way valve (100) communicating with the first flow port (610) via a first liquid inlet channel (611), the first three-way valve (100) communicating with the second flow port (620) via a second liquid inlet channel (612). 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), the second three-way valve (200) is connected to the second flow port (620) through the first liquid outlet channel (612), the second three-way valve (200) is connected to the first flow port (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 driving 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) connects the first liquid inlet channel (611), and the second three-way valve (200) connects the first liquid outlet channel (612); in the second circulation mode, the first three-way valve (100) connects the second liquid inlet channel (621), and the second three-way valve (200) connects the second liquid outlet channel (622); The thermal management method comprises the following steps: Determining that the battery pack (600) has a cooling requirement; Determining whether the thermal management system meets a mode switching condition: If not, controlling the thermal management system to operate in the first cycle mode or the second cycle mode; If so, the thermal management system is controlled to switch between the first cycle mode and the second cycle mode.

2. The thermal management method of the battery pack according to claim 1, characterized in that: The determining that the battery pack (600) has a cooling requirement comprises: Determining whether the temperature of the battery pack (600) reaches a second preset temperature value: If yes, it is determined that the battery pack (600) has a cooling requirement; If not, it is determined that the battery pack (600) has no cooling requirement.

3. The thermal management method of the battery pack according to claim 1, characterized in that: The determining whether the thermal management system meets the mode switching condition includes: Determine whether the battery pack (600) is charged and discharged at a high rate: If not, it is determined that the thermal management system does not meet the mode switching condition.

4. The thermal management method of the battery pack according to claim 3, characterized in that: The determining whether the battery pack (600) is to be charged and discharged at a high rate further includes: If so, determine whether the temperature difference between the first flow opening (610) and the second flow opening (620) reaches a first preset temperature value: If so, determining that the thermal management system satisfies the mode switching condition; If not, it is determined that the thermal management system does not meet the mode switching condition.

5. The thermal management method of the battery pack according to claim 3, characterized in that: The step of determining whether the battery pack (600) is to be charged and discharged at a high rate comprises: Determine whether the operating current of the battery pack (600) is greater than a preset current value and reaches a first preset time length: If yes, determining that the battery pack (600) is to be charged and discharged at a high rate; If not, it is determined that the battery pack (600) is not subjected to high-rate charge and discharge.

6. The thermal management method of the 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 minutes to 20 minutes.

7. The thermal management method of a battery pack according to claim 1, characterized in that: After determining that the battery pack (600) has a cooling demand and before determining whether the thermal management system meets a mode switching condition, the method further includes: It is determined that the thermal management system has not reported a fault.

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

9. The thermal management method of the battery pack according to claim 8, characterized in that: The controlling the thermal management system to alternately switch between the first cycle mode and the second cycle mode according to a preset period includes: after one of the first cycle mode and the second cycle mode ends and before the other starts; The driving pump (300) is controlled to stop running for a second preset time period.

10. The thermal management method of the battery pack according to claim 9, characterized in that: The second preset time length ranges from 20s to 50s.

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

12. A thermal management system, suitable for applying the thermal management method according to any one of claims 1 to 11, characterized in that: The thermal management system comprises: a battery pack (600) and a refrigeration module, the refrigeration module comprising 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) having an internal heat dissipation channel and a first flow port (610) and a second flow port (620) communicating with the internal heat dissipation channel, the first three-way valve (100) communicating with the first flow port (610) via a first liquid inlet channel (611), the first three-way valve (100) communicating with the second flow port (620) via a second liquid inlet channel (612). 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), the second three-way valve (200) is connected to the second flow port (620) through the first liquid outlet channel (612), the second three-way valve (200) is connected to the first flow port (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 driving 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) connects the first liquid inlet channel (611), and the second three-way valve (200) connects the first liquid outlet channel (612); in the second circulation mode, the first three-way valve (100) connects the second liquid inlet channel (621), and the second three-way valve (200) connects the second liquid outlet channel (622).

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

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