Thermal management system

Abstract

The application provides a heat management system, comprising a heat exchanger and M independent load units, a heat dissipation circuit is arranged between the outlet and the inlet of the heat exchanger, and the M load units are connected with the outlet or the inlet of the heat exchanger through a first multi-way valve; wherein, M is greater than or equal to 2, the M load units comprise a target load unit, the target load unit is internally provided with a target heat exchange pipeline, and the target load unit comprises a plurality of sub load units connected in sequence; the target heat exchange pipeline comprises a first flow direction and a second flow direction opposite in direction, so that the first end and the second end of the sub load units connected in sequence are both at the beginning of liquid inlet and at the end of liquid inlet, thereby reducing the temperature difference between the sub load units connected in sequence. The heat management system in the application can independently control the temperature of the plurality of load units and reduce the temperature difference between the sub load units connected in sequence in the target load unit, thereby realizing precise temperature control of the plurality of load devices.

Description

Technical Field

[0001] This application relates to the field of energy storage thermal management technology, and in particular to a thermal management system. Background Technology

[0002] With the development of the energy storage industry, integrated AC / DC energy storage systems have gradually become mainstream. These systems typically involve multiple load devices requiring heat exchange via heat exchangers. However, the optimal operating temperatures for the main heat-generating components of different load devices vary, making precise temperature control of each device impossible and reducing the overall efficiency and lifespan of the integrated AC / DC energy storage system. Furthermore, when a load unit includes multiple sequentially connected sub-load devices, excessive temperature differences between the first and last sub-load devices at the liquid inlet point negatively impact the lifespan of the entire load unit.

[0003] Both the battery pack and the PCS (Power Conversion System) require liquid cooling for heat exchange. Since the battery pack operates optimally at 30-35°C for its lifespan, while the main heat-generating components within the PCS operate at around 50°C, their optimal operating temperatures differ significantly. Currently, liquid coolers are typically single-channel (one inlet, one outlet), connecting the liquid cooling lines of the battery pack and PCS in series. The coolant exchanges heat with the battery pack before exchanging heat with the PCS, and the cooler then controls the supply temperature in real-time based on a shared return temperature. This design fails to ensure that both the battery pack and PCS operate at their optimal temperatures.

[0004] The battery pack usually includes multiple cells connected in sequence by liquid cooling pipes. When the coolant flows through different cells in sequence, due to gravity and flow rate loss in the pipes, the temperature of the cell at the beginning of the liquid inlet is lower than that of the cell at the end of the liquid inlet. The cell at the end of the liquid inlet will degrade earlier than the other cells in the long term, thus creating a bottleneck effect and affecting the operation of the entire battery pack. Utility Model Content

[0005] This application provides a thermal management system to solve the problems in the prior art that it cannot accurately control the temperature of multiple load devices and that there are large temperature differences among multiple sequentially connected sub-load devices.

[0006] This application provides a thermal management system, including a heat exchanger and M load units. A heat dissipation circuit is provided between the liquid outlet and the liquid inlet of the heat exchanger, and the M load units are arranged on the heat dissipation circuit, wherein M≥2.

[0007] The heat dissipation circuit is provided with a first multi-way valve, which includes N ports. One of the N ports is connected to the liquid outlet or liquid inlet of the heat exchanger, and the remaining N-1 ports are respectively connected to M load units one by one, where N = M + 1.

[0008] Among them, the M load units include a target load unit, the target load unit is provided with a target heat exchange pipeline inside, and the target load unit includes a plurality of sub-load units connected in sequence;

[0009] The target heat exchange pipeline includes a first flow direction and a second flow direction. When the target heat exchange pipeline is in the first flow direction, the heat exchange medium of the target heat exchange pipeline flows from the first end to the second end of a plurality of sequentially connected sub-load units. When the target heat exchange pipeline is in the second flow direction, the heat exchange medium of the target heat exchange pipeline flows from the second end to the first end of a plurality of sequentially connected sub-load units.

[0010] The thermal management system disclosed in this application connects one of the N ports of a first multi-way valve to the outlet or inlet of a heat exchanger, and the remaining N-1 ports are connected to M load units one-to-one. This makes each load unit independent, and the opening of the first multi-way valve can be adjusted to allow each load unit to operate at different temperatures, achieving precise temperature control of multiple load units and ensuring that each load unit operates at a suitable temperature. The target load unit includes multiple sub-load units connected in sequence. By setting a first flow direction and a second flow direction with opposite directions, the first end of the multiple sub-load units connected in sequence is both the inlet head of the first flow direction and the inlet tail of the second flow direction, and the second end of the multiple sub-load units connected in sequence is both the inlet tail of the first flow direction and the inlet head of the second flow direction. This avoids the sub-load unit at the first or second end always being located at the inlet head or inlet tail, thereby reducing the temperature difference between the sub-load units and allowing multiple sub-load units to operate simultaneously at a suitable temperature. The thermal management system in this application can achieve independent and precise temperature control of multiple load units, and can be adjusted through a first multi-way valve. It has a simple structure and saves costs. It can also reduce the temperature difference between sub-load units within the target load unit, and further ensure that each sub-load unit is within a suitable temperature range, thereby improving the accuracy of temperature control. Attached Figure Description

[0011] Figure 1 This is a schematic block diagram of a thermal management system provided in an embodiment of this application;

[0012] Figure 2 This is a schematic diagram of the target heat exchange pipeline provided in the embodiments of this application when the flow direction is the first direction;

[0013] Figure 3 This is a schematic diagram of the principle when the target heat exchange pipeline is in the second flow direction, as provided in the embodiments of this application;

[0014] Figure 4 This is a schematic diagram of the target load unit in its first state according to an embodiment of this application;

[0015] Figure 5 This is a schematic diagram of the target load unit in the second state provided in the embodiments of this application;

[0016] Figure 6 This is a schematic diagram illustrating the principle of a first flow path and a second flow path existing simultaneously, as provided in an embodiment of this application.

[0017] Figure 7 This is another principle block diagram of the thermal management system provided in the embodiments of this application;

[0018] Figure 8 This is a flowchart of BMS control of the first multi-way valve provided in an embodiment of this application;

[0019] Figure 9 This is a flowchart of the BMS control switching unit provided in the embodiments of this application.

[0020] Figure label:

[0021] 1. Heat exchanger; 2. First multi-way valve; 3. Load unit; 31. Load device; 32. Heat dissipation channel; 4. Target load unit; 5. Sub-load unit; D1. First end; D2. Second end; 6. Switching unit; 61. First three-way valve; K1. First liquid inlet; K2. First liquid outlet; K3. Second liquid outlet; 62. Second three-way valve; K4. Third liquid outlet; K5. Second liquid inlet; K6. Third liquid inlet; 7. Second multi-way valve. Detailed Implementation

[0022] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0023] Figure 1This application provides a thermal management system including a heat exchanger 1 and M load units 3. A heat dissipation circuit is provided between the outlet and inlet of the heat exchanger 1. The M load units 3 are arranged on the heat dissipation circuit, where M ≥ 2. A first multi-way valve 2 is provided on the heat dissipation circuit. The first multi-way valve 2 includes N ports. One of the N ports is connected to either the outlet or inlet of the heat exchanger 1, and the remaining N-1 ports are respectively connected to the M load units 3 in a one-to-one correspondence, where N = M + 1. The M load units 3... The system includes a target load unit 4, which has a target heat exchange pipeline inside. The target load unit 4 also includes a plurality of sub-load units 5 connected in sequence. The target heat exchange pipeline has a first flow direction and a second flow direction. When the target heat exchange pipeline has the first flow direction, the heat exchange medium of the target heat exchange pipeline flows from the first end D1 to the second end D2 of the plurality of sub-load units 5 connected in sequence. When the target heat exchange pipeline has the second flow direction, the heat exchange medium of the target heat exchange pipeline flows from the second end D2 to the first end D1 of the plurality of sub-load units 5 connected in sequence.

[0024] In the embodiments of this application, reference is made to Figure 1 , Figure 1 A schematic diagram of a thermal management system is shown. In this application, heat exchanger 1 provides heat exchange medium for each load unit 3. Heat exchanger 1 can both cool and heat each load unit 3. The specific type of heat exchanger 1 is not limited; for example, heat exchanger 1 can be a liquid chiller or a heater, etc. Load unit 3 can be a unit that exchanges heat for PCS, or a unit that exchanges heat for battery packs, battery compartments, etc. By connecting one of the N ports of the first multi-way valve 2 to the outlet or inlet of the heat exchanger 1, and connecting the remaining N-1 ports to M load units 3 respectively, each load unit 3 is independent of each other. By adjusting the opening of the first multi-way valve 2, each load unit 3 can be independently adjusted, allowing different load units 3 to operate at different temperatures. This achieves the purpose of precise temperature control of multiple load units 3, ensuring that each load unit 3 operates at a suitable temperature. It is understandable that the opening range of the first multi-way valve 2 is 0%-100%. When the opening of one or more ports connected to the load unit 3 of the first multi-way valve 2 is 0%, the heat exchange passage of the corresponding load unit 3 is completely closed, which is suitable for scenarios where the load device 31 on the load unit 3 does not need to perform heat exchange. When the opening of a port connected to the load unit 3 of the first multi-way valve 2 is 100%, the heat exchange passage of the load unit 3 is completely open, and correspondingly, the heat exchange passages of the other load units 3 are completely closed, which is suitable for scenarios where only the load device 31 on the load unit 3 needs to perform heat exchange.

[0025] The target load unit 4 is one of the M load units 3. The target load unit 4 includes multiple sub-load units 5 connected in sequence. The heat exchange pipes of the multiple sub-load units 5 can be independent of each other or connected in series. The sub-load units 5 can be units that exchange heat for the PCS, for the battery pack, for the battery cluster, or for the battery cell, etc. The target load unit 4 has a target heat exchange pipe inside, which includes a first flow direction and a second flow direction. One end of the multiple sub-load units 5 connected in sequence is the first end D1, and the other end is the second end D2. The heat exchange medium in the thermal management system is a liquid, such as an aqueous solution of ethylene glycol, a synthetic oil-based coolant, a fluorinated liquid, etc.

[0026] refer to Figure 1 When the target heat exchange pipeline is in the first flow direction, the heat exchange medium flows from the first end D1 to the second end D2 of the sequentially connected sub-load units 5; when the target heat exchange pipeline is in the second flow direction, the heat exchange medium flows from the second end D2 to the first end D1 of the sequentially connected sub-load units 5. It can be understood that the first and second flow directions are opposite. By setting the first and second flow directions in the target heat exchange pipeline, the first end D1 of the sequentially connected sub-load units 5 is located both at the beginning and end of the liquid inlet in the first flow direction of the target heat exchange pipeline; similarly, the second end D2 of the sequentially connected sub-load units 5 is located both at the end and beginning of the liquid inlet in the first flow direction of the target heat exchange pipeline. This can prevent the first end D1 and the second end D2 of the sequentially connected sub-load units 5 from always being at the first or last liquid inlet position, thereby avoiding the problem of excessive temperature difference between the first end D1 and the second end D2, thus improving the temperature uniformity of the sequentially connected sub-load units 5, avoiding the formation of a short-board effect, and improving the service life of the sub-load devices on the sub-load unit 5.

[0027] Optionally, refer to Figure 1 The load unit 3 includes a load device 31 and a heat dissipation channel 32, with the load device 31 in contact with the heat dissipation channel 32; the remaining N-1 ports of the N ports are respectively connected to the heat dissipation channels 32 of the M load units 3.

[0028] Specifically, the load device 31 can be a PCS, battery pack, battery compartment, etc., and this application embodiment is not limited to any particular type. The heat dissipation channel 32 is a carrier for the flow of the heat dissipation medium. The load device 31 can be immersed in liquid cooling and submerged in the heat exchange medium. The load unit 3 can also include a cold plate, which has flow channels inside for the flow of the heat exchange medium. The load device 31 contacts the cold plate for heat exchange. For example, the load unit 3 can include a battery pack and the heat dissipation channel 32. The battery pack can be immersed in an insulating heat exchange medium or can indirectly contact the heat exchange medium through the cold plate for heat exchange.

[0029] In some optional embodiments, the target heat exchange pipeline is further provided with a switching unit 6, which includes a first state and a second state; when the switching unit 6 is in the first state, the target heat exchange pipeline is in the first flow direction; when the switching unit 6 is in the second state, the target heat exchange pipeline is in the second flow direction.

[0030] In the embodiments of this application, reference is made to Figure 2 When the switching unit 6 is in the first state, the target heat exchange pipeline is in the first flow direction. The first end D1 of the sequentially connected sub-load unit 5 is located at the liquid inlet in the first flow direction. When in cooling mode, the temperature of the first end D1 is relatively lower than the temperature of the second end D2. (Reference) Figure 3 When the switching unit 6 is in the second state, the target heat exchange pipeline is in the second flow direction. The second end D2 of the sequentially connected sub-load unit 5 is located at the liquid inlet of the first flow direction. When in cooling mode, the temperature of the first end D1 is relatively higher than the temperature of the second end D2. The switching unit 6 includes a first state and a second state. By switching between the first state and the second state, the temperature difference between the first end D1 and the second end D2 of the sequentially connected sub-load unit 5 is reduced. This improves the temperature uniformity of the sequentially connected sub-load units 5 within a single heat exchange pipeline, thereby avoiding the bottleneck effect and extending the service life of the sub-load units 5. Based on the traditional single-inlet, single-outlet, single-flow pipeline, only the switching unit 6 needs to be added; there is no need to add the entire pipeline, resulting in low modification costs.

[0031] Optionally, the switching unit 6 includes a first three-way valve 61 and a second three-way valve 62; the first three-way valve 61 includes a first inlet end K1, a first outlet end K2, and a second outlet end K3, the first inlet end K1 is connected to the inlet of the target heat exchange pipeline, the first outlet end K2 is connected to the first end D1 of the sub-load unit 5 connected in sequence, and the second outlet end K3 is connected to the second end D2 of the sub-load unit 5 connected in sequence; the second three-way valve 62 includes a third outlet end K4, a second inlet end K5, and a third inlet end K6, the third outlet end K4 is connected to the outlet of the target heat exchange pipeline, the second inlet end K5 is connected to the second end D2 of the sub-load unit 5 connected in sequence, and the third inlet end K6 is connected to the first end D1 of the sub-load unit 5 connected in sequence.

[0032] In the embodiments of this application, reference is made to Figure 2 and Figure 3 The first three-way valve 61 is located at the liquid inlet of the target heat exchange pipeline, and the second three-way valve 62 is located at the liquid outlet of the target heat exchange pipeline. By simultaneously controlling the switching between the first liquid outlet K2 and the second liquid outlet K3 of the first three-way valve 61, and the switching between the second liquid inlet K5 and the third liquid inlet K6 of the second three-way valve 62, the state switching of the switching unit 6 is realized. Moreover, the switching between the first state and the second state is realized through the first three-way valve 61 and the second three-way valve 62, which has a simple structure and saves costs.

[0033] Furthermore, when the switching unit 6 is in the first state, the first inlet end K1 is connected to the first outlet end K2, the second outlet end K3 is disconnected, the third outlet end K4 is connected to the second inlet end K5, and the third inlet end K6 is disconnected; when the switching unit 6 is in the second state, the first inlet end K1 is connected to the second outlet end K3, the first outlet end K2 is disconnected, the third outlet end K4 is connected to the third inlet end K6, and the second inlet end K5 is disconnected.

[0034] In the embodiments of this application, reference is made to Figure 4 When the switching unit 6 is in the first state, the first liquid inlet K1 is connected to the first liquid outlet K2, the second liquid outlet K3 is disconnected, and the first end D1 of the sequentially connected sub-load unit 5 is located at the first liquid inlet position; the third liquid outlet K4 is connected to the second liquid inlet K5, the third liquid inlet K6 is disconnected, and the second end D2 of the sequentially connected sub-load unit 5 is located at the last liquid inlet position; when in cooling mode, the temperature of the first end D1 is lower than the temperature of the second end D2, and when in heating mode, the temperature of the first end D1 is higher than the temperature of the second end D2. Similarly, refer to... Figure 5When the switching unit 6 is in the second state, the second end D2 of the sequentially connected sub-load unit 5 is at the first liquid inlet position, and the first end D1 is at the last liquid inlet position. In cooling mode, the temperature of the second end D2 is lower than the temperature of the first end D1; in heating mode, the temperature of the second end D2 is higher than the temperature of the first end D1. The switching between the first and second states is achieved by controlling the opening and closing of each port of the first three-way valve 61 and the second three-way valve 62. This back-and-forth switching between the first and second states allows for temperature difference control of each sequentially connected sub-load unit 5.

[0035] In some alternative embodiments, reference is made to Figure 6 The target heat exchange pipeline includes two independent first flow pipelines and second flow pipelines. The heat exchange medium in the first flow pipeline flows from the first end D1 to the second end D2 of a plurality of sequentially connected sub-load units 5, and the heat exchange medium in the second flow pipeline flows from the second end D2 to the first end D1 of a plurality of sequentially connected sub-load units 5.

[0036] In the embodiments of this application, reference is made to Figure 6 In the first flow path, the heat exchange medium flows from the first end D1 of the sequentially connected sub-load units 5 to the second end D2; in the second flow path, the heat exchange medium flows from the second end D2 of the sequentially connected sub-load units 5 to the first end D1. It can be understood that the flow directions of the first and second flow paths are opposite. The first end D1 of the sequentially connected sub-load units 5 is located at the beginning of the liquid inlet of the first flow path and at the end of the liquid inlet of the second flow path. The second end D2 of the sequentially connected sub-load units 5 is located at the end of the liquid inlet of the first flow path and at the beginning of the liquid inlet of the second flow path. By setting two flow paths with opposite directions, the first and second flow paths, to exchange heat for multiple sub-load devices simultaneously, can reduce the temperature difference between the sub-load devices within the same target load unit 4, so that each sub-load device is at a suitable temperature and extend the service life of each sub-load device. Based on the traditional single-loop, single-direction flow system with one inlet and one outlet, no changes to the existing piping are required. Only a new piping system needs to be added, which does not affect the operation of the original system and allows for rapid piping modification. Furthermore, there is no need to switch between the first and second flow directions, which helps reduce the failure rate and improves the stability of the thermal management system.

[0037] Optionally, the sub-load unit 5 includes a sub-load device and a sub-heat dissipation channel. The sub-load device is in contact with the corresponding sub-heat dissipation channel, and multiple sub-heat dissipation channels are connected in sequence. One end of the sub-heat dissipation channel is connected to the liquid outlet or liquid inlet of the heat exchanger 1, and the other end is connected to one of the N-1 ports of the first multi-way valve 2.

[0038] Specifically, the sub-load device can be a PCS, battery cell, etc., without limitation. The sub-heat dissipation channel is the carrier for the flow of the heat dissipation medium. The sub-load device can be immersed in liquid cooling and submerged in the heat exchange medium. The sub-load unit 5 can also include a cold plate with a flow channel inside for the flow of the heat exchange medium. The sub-load device contacts the cold plate for heat exchange. When the target heat exchange pipeline switches between the first and second states through the switching unit 6, the sub-load device can use immersion liquid cooling or contact the cold plate for heat exchange. When the target heat exchange pipeline is connected to two opposite flow channels, the sub-load device can simultaneously contact the cold plates of the first and second flow channels for heat exchange, or it can use immersion liquid cooling. The container holding the heat exchange medium is connected to both the first and second flow channels simultaneously to achieve temperature difference control of each sub-load device in the same sub-load unit 5.

[0039] Optionally, refer to Figure 5 The target load unit 4 includes multiple battery cluster units, and each battery cluster unit includes multiple cell units connected in sequence.

[0040] For example, refer to Figure 6 The target load unit 4 includes a battery pack, and the sub-load devices are battery cells. The battery pack includes 6 battery clusters, and each battery cluster includes 8 battery cells. The heat exchange pipelines corresponding to the 6 battery clusters are independent of each other. The sub-load units 5 corresponding to the 8 battery cells are independent of each other and connected sequentially. Cell #1 is located at the first end D1 of the sequentially connected sub-load units 5, and cell #8 is located at the second end D2 of the sequentially connected sub-load units 5. In cooling mode, when the target heat exchange pipeline is in the first flow direction, cell #1 is closer to the liquid inlet of the target heat exchange pipeline than cell #8, and the heat exchange medium flows from the direction of cell #1 to the direction of cell #8. The temperature of cell #1 is lower than that of cell #8. When the target heat exchange pipeline is in the second flow direction, cell #8 is closer to the liquid inlet of the target heat exchange pipeline than cell #1, and the heat exchange medium flows from the direction of cell #8 to the direction of cell #1. The temperature of cell #8 is lower than that of cell #1. By setting the first flow direction and the second flow direction, the temperature difference between cell #1 and cell #8 can be reduced, making the temperature within each battery cluster more uniform, thereby controlling the temperature difference within the battery pack, avoiding the weakest link effect, and extending the service life of each cell.

[0041] For example, there are three load units 3. The target load unit 3 includes two PCSs with the same power and heat output. The target heat exchange pipeline is connected to two sub-load units 5 connected in sequence, and each sub-load unit 5 has one PCS. The other two load units 3 each have a battery pack with different capacities and heat outputs. The corresponding first multi-way valve 2 is a four-way valve. By controlling the three load units 3 separately through the four-way valve, the heat exchange and temperature control of the PCS and the two battery packs can be achieved independently. By setting the first flow direction and the second flow direction, the temperature difference between the two PCSs can be reduced, so that the two PCSs and the two battery packs are all at a suitable operating temperature.

[0042] Optionally, refer to Figure 7 The thermal management system further includes a second multi-way valve 7, which has N ports. When the first multi-way valve 2 is located at the outlet of the heat exchanger 1, one of the N ports of the second multi-way valve 7 is connected to the inlet of the heat exchanger 1, and the remaining N-1 ports of the second multi-way valve 7 are respectively connected to M load units 3 in a one-to-one correspondence. When the first multi-way valve 2 is located at the inlet of the heat exchanger 1, one of the N ports of the second multi-way valve 7 is connected to the outlet of the heat exchanger 1, and the remaining N-1 ports of the second multi-way valve 7 are respectively connected to M load units 3 in a one-to-one correspondence.

[0043] For example, refer to Figure 7 A first multi-way valve 2 and a second multi-way valve 7 are provided on the heat dissipation circuit between the liquid outlet and the liquid inlet of heat exchanger 1. The first multi-way valve 2 is located at the liquid outlet of heat exchanger 1, and the second multi-way valve 7 is located at the liquid inlet of heat exchanger 1. The N-1 ports of the first multi-way valve 2 correspond one-to-one with the N-1 ports of the second multi-way valve 7. The corresponding ports of the first multi-way valve 2 and the second multi-way valve 7 have the same opening degree and are adjusted simultaneously. The setting of two multi-way valves provides a certain degree of redundancy to the thermal management system. When one of the first multi-way valve 2 and the second multi-way valve 7 fails, the independent temperature control of multiple load units 3 can still be achieved by adjusting the opening degree of the other.

[0044] Optionally, the thermal management system further includes a BMS (battery system), the BMS including an information acquisition unit and a control unit; the information acquisition unit includes M first temperature sensors, each of the first temperature sensors being located on the corresponding load unit 3; the control unit is used to adjust the opening degree of the first multi-way valve 2 and the second multi-way valve 7 according to the first temperature sensors.

[0045] Specifically, BMS (Battery Management System), also known as battery nanny or battery manager, is used for intelligent management and maintenance of each battery cell, monitoring the battery status, preventing overcharging and over-discharging, and thus extending the battery's lifespan.

[0046] In this embodiment, the first temperature sensor is located on the load unit 3, specifically on the main heat-generating component of the load device 31 in each load unit 3. By controlling the opening of the first multi-way valve 2 through the BMS, precise temperature control of multiple load units 3 is achieved. Utilizing the first temperature sensor in the existing BMS information acquisition unit eliminates the need for additional temperature measurement equipment, thus improving the efficiency of the thermal management system and reducing costs.

[0047] For details, please refer to Figure 8 When in cooling mode, the BMS controls the opening of the first multi-way valve 2 as follows:

[0048] S101: Collect the highest temperature of each load device 31; collect the highest temperature T of the i-th load device 31 through each first temperature sensor. i,max , 1≤i≤M;

[0049] S102: Calculate the cooling capacity required by each load device 31; specifically, the control unit calculates the cooling capacity required by the highest temperature T of the i-th load device 31 collected by each first temperature sensor. i,max And the ideal operating temperature T of the i-th load device 31 i,x Calculate T i,max With T i,x Temperature difference T between i,c =T i,max -T i,x That is, equivalent to the cooling capacity required by each load device 31;

[0050] S103: Calculate the opening degree; the control unit calculates the opening degree ratio of the ports connected to the first multi-way valve 2 and each load unit 3 according to the cooling capacity required by each load device 31, and the port opening degree corresponding to the i-th load unit 3 is K. i,c =T i,c / (T 1,c +T 2,c +...+T i,c );

[0051] S104: Adjust the opening degree; the BMS control unit adjusts the opening degree K according to the calculation. i,c An electrical signal is generated to adjust the opening degree of the first multi-way valve 2 and the corresponding port of each load device 31, thereby adjusting the flow rate of the heat exchange medium in each load unit 3, so that each load device 31 is at a suitable operating temperature.

[0052] Furthermore, when in heating mode, the BMS controls the opening degree of the first multi-way valve 2 as follows:

[0053] S201: Collect the lowest temperature of each load device 31; collect the lowest temperature of the i-th load device 31 as T through the first temperature sensor. i,min , 1≤i≤M;

[0054] S202: Calculate the heating requirement of each load device 31; based on the minimum temperature T of the i-th load device 31 collected by the BMS. i,min and the minimum operating temperature T of the i-th load device 31 i,o Calculate T i,min With T i,o Temperature difference T between i,h T i,h =T i,o -T i,min Temperature difference T i,,h This is equivalent to the heating demand of each load device 31; where the minimum operating temperature T i,o The temperature can be determined by the performance of each load device 31. For example, the battery pack and PCS can be set to 15°C. This application embodiment does not make specific limitations.

[0055] S203: Calculate the opening degree; based on the heating requirements of each load device 31, calculate the opening degree ratio of the ports connected to the first multi-way valve 2 and each load unit 3, where the port opening degree corresponding to the i-th load unit 3 is K. i,h =T i,h / (T 1,h +T 2,h +...+T i,h );

[0056] S204: Control opening degree; the BMS control unit calculates the opening degree K. i,h An electrical signal is generated to adjust the opening degree of the first multi-way valve 2 and the corresponding port of each load device 31, thereby adjusting the flow rate of the heat exchange medium in each load unit 3, so that each load device 31 is at a suitable operating temperature.

[0057] Optionally, the information acquisition unit further includes a plurality of second temperature sensors, the second temperature sensors being located on the sub-load unit 5; the control unit is also used to adjust the state of the switching unit 6 according to the second temperature sensors.

[0058] In this embodiment, the second temperature sensor is located on the sub-load unit 5, specifically on the main heat-generating device of the sub-load equipment in each sub-load unit 5. By controlling the connection or disconnection of the first liquid outlet K2 and the second liquid outlet K3 through the BMS, and simultaneously controlling the connection or disconnection of the second liquid inlet K5 and the third liquid inlet K6, the switching unit 6 is switched between the first and second states, thereby switching the first and second flow directions of the target heat exchange pipeline and controlling the temperature difference of the sub-load equipment in the sequentially connected sub-load units 5. Utilizing the second temperature sensor in the existing BMS information acquisition unit eliminates the need for additional temperature measurement equipment, enabling state switching of the switching unit 6, improving the efficiency of the thermal management system, and reducing costs.

[0059] For details, please refer to Figure 9 The method for controlling the switching unit 6 of the BMS is as follows:

[0060] S301: The second temperature sensor collects the temperature of each sub-load device. The temperature of the j-th sub-load device is collected as T by the second temperature sensor. j,z ;

[0061] S302: Calculate the maximum temperature difference of each sub-load device. The control unit calculates the maximum temperature difference based on the collected temperature T of each sub-load device. j,z The maximum and minimum values ​​are obtained, and then the maximum temperature difference T of each sub-load device is calculated. △ ;

[0062] S303: Determine the status of switching unit 6. Specifically, this is done by determining the maximum temperature difference T. △ The relationship between the temperature difference threshold T′ and the temperature difference threshold T′ determines whether to switch the state of the switching unit 6; wherein, the specific value of the temperature difference threshold T′ can be set according to actual needs, such as 3℃, 4℃ or 5℃, and this application embodiment does not make a specific limitation.

[0063] S3031: When the maximum temperature difference T △ When the temperature difference threshold T′ is reached, the state of the switching unit 6 is switched, that is, the switching unit 6 is switched from the first state to the second state, or from the second state to the first state;

[0064] S3032: When the maximum temperature difference T △ When the temperature difference threshold T′ is less than or equal to the temperature difference threshold, the state remains unchanged during the switching process.

[0065] In this embodiment, the BMS controls the switching unit 6 in real time based on the temperature of the sub-load devices collected by each second temperature sensor. That is, after step S303 ends, step S301 is re-executed, and the cycle continues. For example, the target load unit 4 includes a battery pack, the sub-load devices are battery cells, the battery pack includes 6 battery clusters, each battery cluster includes 8 battery cells, the target sub-heat exchange pipelines corresponding to the 6 battery clusters are independent of each other, and the sub-load units 5 corresponding to the 8 battery cells are connected sequentially to each other. (Reference) Figure 8 In cooling mode, the temperature of each sub-load device is measured and the temperature difference between them is calculated. When the temperature difference exceeds a threshold, the BMS control unit sends an electrical signal to control the first three-way valve 61 to switch the connection or disconnection of the first liquid outlet K2 and the second liquid outlet K3, and simultaneously controls the second three-way valve 62 to switch the connection or disconnection of the second liquid inlet K5 and the third liquid inlet K6. Specifically, the BMS control unit can control the state switching of the switching unit 6 when the temperature difference between any eight cells in one of the six battery clusters exceeds the temperature difference threshold, or when the temperature difference between 48 cells exceeds the temperature difference threshold. This embodiment of the application does not limit the scope of the application.

[0066] refer to Figure 1-9 The following example illustrates the content of this application by controlling two load units 3 in cooling mode using heat exchanger 1. The load device on the target load unit 4 is a battery pack, and the load device on the other load unit 3 is a PCS. The K7 port of the first multi-way valve 2 is connected to the liquid outlet of heat exchanger 1, the K8 port is connected to the liquid inlet of the target load unit 4, and the K9 port is connected to the liquid inlet of the other load unit 3; the K... 10 The port is connected to the liquid inlet of heat exchanger 1, K 11 The port is connected to the liquid outlet of the target load unit 4, K 12 The port is connected to the liquid outlet of another load unit 3; the piping of the target load unit 4 and the other load unit 3 are independent of each other. The first temperature sensor of the BMS detects the temperature of the battery pack and PCS in real time, and the control unit determines the opening degree K according to the formula K in the cooling mode. i,c =T i,c / (T 1,c +T 2,c +...+T i,c ), and the opening degree K in heating mode. i,h =T i,h / (T 1,h +T 2,h +...+T i,h) Calculate the opening degree of each port of the first multi-way valve 2 and the second multi-way valve 7 connected to the battery pack and PCS, and generate electrical signals. Then, simultaneously adjust the K8 and K9 ports of the first multi-way valve 2 and the K port of the second multi-way valve 7. 11 Port, K 12 The opening degree of the ports, wherein the K8 port of the first multi-way valve 2 and the K port of the second multi-way valve 7. 11 The ports have the same opening degree; the K9 port of the first multi-way valve 2 and the K port of the second multi-way valve 7... 12 The ports are opened at the same degree, thereby regulating the flow rate of the heat exchange medium in the two load units 3, so that the battery pack and PCS are both at a suitable operating temperature.

[0067] The battery pack includes 6 battery clusters, each battery cluster includes 8 cells, and the target load unit 4 includes 6 independent battery cluster heat exchange pipes. Each battery cluster pipe includes 8 cell heat exchange pipes connected in sequence. The 8 cell heat exchange pipes can be independent of each other or connected in series. There is no restriction here.

[0068] When the temperature difference control inside the target load unit 4 is achieved by switching between the first and second states through the switching unit 6, such as... Figure 4 In the block diagram shown, within the same battery cluster, the heat exchange medium flows first through cell #1 and last through cell #8. This means cell #1 is located at the beginning of the heat exchange pipeline in the battery cluster, and cell #8 is located at the end. Due to unavoidable heat loss during the heat exchange medium transport process, cell #1 has a lower temperature than cell #8, indicating a temperature difference between the cells within the same battery cluster. The BMS's second sensor monitors the temperature of each cell in real time and calculates the maximum temperature difference T between the cells. △ By determining the maximum temperature difference T △ The relationship between the value of T and the temperature difference threshold T′ determines whether to switch the state of switching unit 6. When T △ When T > T′, the state of switching unit 6 is switched; when T △ When T ≤ T′, the state remains unchanged during the state transition.

[0069] When temperature difference control is performed inside target load unit 4 through first and second flow pipes in opposite directions, such as Figure 6 As shown, since cell #1 is located at both the first liquid inlet of the first flow pipe and the last liquid inlet of the second flow pipe, the temperature difference between cell #1 and cell #8 can be controlled, thereby controlling the temperature difference between each sub-load device, ensuring that each cell is at a suitable operating temperature, avoiding the bottleneck effect, and extending the service life of the battery pack.

[0070] It should be understood that the thermal management system in this application can be used not only for energy storage systems to exchange heat for PCS, battery packs, battery compartments, etc., but also for other fields to exchange heat for other load devices, such as high-performance computers, high-speed operating equipment that requires cooling, etc.

[0071] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application 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.

[0072] 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 system, characterized in that, include: A heat exchanger (1) and M load units (3) are provided. A heat dissipation circuit is provided between the liquid outlet and the liquid inlet of the heat exchanger (1). M load units (3) are arranged on the heat dissipation circuit, where M≥2. The heat dissipation circuit is provided with a first multi-way valve (2), which includes N ports. One of the N ports is connected to the liquid outlet or liquid inlet of the heat exchanger (1), and the remaining N-1 ports are respectively connected to M load units (3) one by one, where N = M + 1. Among them, the M load units (3) include a target load unit (4), the target load unit (4) is provided with a target heat exchange pipeline inside, and the target load unit (4) includes a plurality of sub-load units (5) connected in sequence; The target heat exchange pipeline includes a first flow direction and a second flow direction. When the target heat exchange pipeline is in the first flow direction, the heat exchange medium of the target heat exchange pipeline flows from the first end (D1) to the second end (D2) of the multiple sub-load units (5) connected in sequence. When the target heat exchange pipeline is in the second flow direction, the heat exchange medium of the target heat exchange pipeline flows from the second end (D2) to the first end (D1) of the multiple sub-load units (5) connected in sequence.

2. The thermal management system according to claim 1, characterized in that, The load unit (3) includes a load device (31) and a heat dissipation channel (32), wherein the load device (31) is in contact with the heat dissipation channel (32); The remaining N-1 ports of the N ports are respectively connected to the heat dissipation channels (32) of the M load units (3).

3. The thermal management system according to claim 1, characterized in that, The target heat exchange pipeline is also provided with a switching unit (6), which includes a first state and a second state; When the switching unit (6) is in the first state, the target heat exchange pipeline is in the first flow direction; When the switching unit (6) is in the second state, the target heat exchange pipeline is in the second flow direction.

4. The thermal management system according to claim 3, characterized in that, The switching unit (6) includes a first three-way valve (61) and a second three-way valve (62); The first three-way valve (61) includes a first liquid inlet (K1), a first liquid outlet (K2), and a second liquid outlet (K3). The first liquid inlet (K1) is connected to the liquid inlet of the target heat exchange pipeline, the first liquid outlet (K2) is connected to the first end (D1) of the sub-load unit (5) connected in sequence, and the second liquid outlet (K3) is connected to the second end (D2) of the sub-load unit (5) connected in sequence. The second three-way valve (62) includes a third liquid outlet (K4), a second liquid inlet (K5), and a third liquid inlet (K6). The third liquid outlet (K4) is connected to the liquid outlet of the target heat exchange pipeline. The second liquid inlet (K5) is connected to the second end (D2) of the sub-load unit (5) connected in sequence. The third liquid inlet (K6) is connected to the first end (D1) of the sub-load unit (5) connected in sequence.

5. The thermal management system according to claim 4, characterized in that, When the switching unit (6) is in the first state, the first liquid inlet (K1) is connected to the first liquid outlet (K2), the second liquid outlet (K3) is disconnected, the third liquid outlet (K4) is connected to the second liquid inlet (K5), and the third liquid inlet (K6) is disconnected. When the switching unit (6) is in the second state, the first liquid inlet (K1) is connected to the second liquid outlet (K3), the first liquid outlet (K2) is disconnected, the third liquid outlet (K4) is connected to the third liquid inlet (K6), and the second liquid inlet (K5) is disconnected.

6. The thermal management system according to claim 1, characterized in that, The target heat exchange pipeline includes two independent first flow pipelines and second flow pipelines. The first flow pipeline flows from the first end (D1) of a plurality of sub-load units (5) connected in sequence to the second end (D2), and the second flow pipeline flows from the second end (D2) of a plurality of sub-load units (5) connected in sequence to the first end (D1).

7. The thermal management system according to claim 1, characterized in that, The target load unit (4) includes multiple battery cluster units, and each battery cluster unit includes multiple cell units connected in sequence.

8. The thermal management system according to claim 1, characterized in that, It also includes a second multi-way valve (7), which has N ports; When the first multi-way valve (2) is located at the outlet of the heat exchanger (1), one of the N ports of the second multi-way valve (7) is connected to the inlet of the heat exchanger (1), and the remaining N-1 ports of the second multi-way valve (7) are respectively connected to the M load units (3) one by one. When the first multi-way valve (2) is located at the inlet of the heat exchanger (1), one of the N ports of the second multi-way valve (7) is connected to the outlet of the heat exchanger (1), and the remaining N-1 ports of the second multi-way valve (7) are respectively connected to the M load units (3) one by one.

9. The thermal management system according to claim 3, characterized in that, It also includes a BMS, which comprises an information acquisition unit and a control unit; The information acquisition unit includes M first temperature sensors, each of which is located on the corresponding load unit (3); The control unit is used to adjust the opening degree of the first multi-way valve (2) according to the first temperature sensor.

10. The thermal management system according to claim 9, characterized in that, The information acquisition unit also includes a plurality of second temperature sensors, each of which is located on the corresponding sub-load unit (5); The control unit is also used to switch the state of the switching unit (6) according to the second temperature sensor.

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