Multi-channel heat exchanger, heat management system and method and light storage equipment

Abstract

The invention relates to a multi-channel heat exchanger, a heat management system and method and light storage equipment, and relates to the technical field of heat management. The multi-channel heat exchanger is provided with a flow channel structure with refrigerant channels arranged among a plurality of cooling liquid channels. The heat management system takes the heat exchanger as a core and integrates a refrigerant loop, a power loop, a battery loop, an air-liquid heat exchanger and a valve unit; through intelligent switching of the valve unit, the connection relation between each loop and different channels of the heat exchanger can be dynamically reconfigured, and various heat exchange loops are formed. Through the flow channel design of the multi-channel heat exchanger and the reconfigurable topology of the heat management system, the heat mixing problem between the battery and the cooling liquid of the power conversion device is solved, and all-working-condition heat management of high-temperature independent cold supplement, medium and low-temperature natural cooling or waste heat recovery and low-temperature heating and heat preservation is achieved; and the temperature control precision, the energy efficiency and the operation reliability of the system are obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal management, in particular to a multi-channel heat exchanger, a thermal management system and method, and a light storage device. BACKGROUND

[0002] With the development of photovoltaic energy storage systems towards high power density and wide temperature range applications, the thermal management system needs to provide sufficient and non-interfering cooling at high temperatures, while being able to efficiently utilize waste heat or natural cooling sources at medium and low temperatures, and ensure high reliability in long-term operation.

[0003] In the current common solution, the battery and the power conversion device exchange heat through the same heat exchanger, and the two liquid circuits can be connected in series through a valve to realize waste heat recovery or natural cooling. However, this solution has certain defects: first, since the layout of the heat exchanger channels is fixed, the system cannot provide an independent and strengthened cooling path for the power conversion device under high temperature or overload; at the same time, the required cooling liquid temperature of the battery (about 18-25℃) and the required cooling liquid temperature of the power conversion device (about 50-60℃) are significantly different, and heat transfer between the two liquid circuits in the heat exchanger (i.e. heat transfer) is likely to occur, making it difficult for both to achieve precise temperature control. Secondly, in the series mode, the cooling liquids of the two liquid circuits are forced to mix and flow, and fluids of different temperatures and pressures are in direct contact, not only causing temperature and hydraulic shock, but also exacerbating the risk of pipeline sealing aging and leakage in long-term operation, seriously affecting the stability of the system. SUMMARY

[0004] In order to solve the problems of heat transfer, independent cooling, reliability and stability caused by the liquid circuit series connection in the prior art due to the structure of the heat exchanger, the present application provides a multi-channel heat exchanger, a thermal management system and method, and a light storage device. The technical solution adopted is as follows: A multi-channel heat exchanger, comprising a plurality of repeatedly arranged flow channel units, each of the flow channel units comprising a refrigerant channel and a plurality of cooling liquid channels, the refrigerant channel being arranged between the plurality of cooling liquid channels.

[0005] In a specific implementation scheme, each of the flow channel units comprises, in sequence, a first cooling liquid channel, a refrigerant channel, a second cooling liquid channel, and a third cooling liquid channel.

[0006] A thermal management system, comprising the multi-channel heat exchanger, a refrigerant circuit, a power circuit, a battery circuit, a wind-liquid heat exchanger, and a valve unit. The air-liquid heat exchanger has a refrigerant side and a coolant side; the refrigerant circuit comprises the refrigerant side of the air-liquid heat exchanger, and the inlet and outlet of the refrigerant circuit are respectively connected to the refrigerant channel of the multi-channel heat exchanger through pipelines, and exchange heat with the battery circuit and the power circuit, so as to cool the coolant of the battery circuit and the coolant of the power circuit. The power circuit comprises a power device, and the inlet of the power circuit is connected to the valve unit and the coolant side outlet of the air-liquid heat exchanger through a pipeline, and the outlet of the power circuit is connected to the coolant side inlet of the air-liquid heat exchanger through a pipeline; the power circuit can also be connected to the coolant channel of the multi-channel heat exchanger through the valve unit, and exchange heat with the refrigerant circuit, so as to cool the power device. The battery circuit comprises a battery device, and the inlet of the battery circuit is connected to the valve unit and the coolant channel outlet of the multi-channel heat exchanger through a pipeline, and the outlet of the battery circuit is connected to the coolant channel inlet of the multi-channel heat exchanger through a pipeline; the battery circuit can be connected to part or all of the coolant channels, and exchange heat with the refrigerant circuit, so as to cool the battery device.

[0007] In a specific embodiment, the valve unit comprises a valve group and a three-way valve; the inlet of the battery circuit is connected to the valve group through a pipeline, and is connected to the coolant channel of the multi-channel heat exchanger through the valve group; the outlet of the battery circuit is connected to the three-way valve through a pipeline, and is connected to the coolant channel of the multi-channel heat exchanger through the three-way valve, and exchange heat with the refrigerant circuit, so as to cool the battery device; one of the two coolant channels can be connected in parallel to the battery circuit, and one of the two coolant channels can be used as a heat insulation channel between the battery circuit and the power circuit; the inlet of the power circuit is connected to the valve group and the outlet of the air-liquid heat exchanger through a pipeline, and the power circuit can also be connected to the coolant channel of the multi-channel heat exchanger through the valve group, and exchange heat with the refrigerant circuit, so as to cool the power device.

[0008] In one specific embodiment, the thermal management system further comprises battery pack branches, each of which comprises a battery pack and a control valve, the inlet and outlet of each of the battery pack branches being connected in parallel to the inlet and outlet of the battery circuit through pipes, and the control valve being used to adjust the flow of the coolant in each of the battery pack branches to balance the temperature of each of the battery pack branches; and / or a throttling branch, which comprises a throttling valve, the inlet and outlet of the throttling branch being connected to the outlet and inlet of the power device through pipes; the throttling branch can be connected in parallel to the power circuit and exchange heat with the power circuit to increase the temperature of the coolant at the inlet of the power device.

[0009] A thermal management method applied to the thermal management system described above, comprising the following steps: Obtaining the working condition parameters of the thermal management system, the working condition parameters including one or more of the ambient temperature, the temperature of the power device, the temperature of the battery device, and the load of the thermal management system; Based on the working condition parameters, controlling the working state of the valve unit to connect the coolant circuit, the battery circuit, and the power circuit in series or in parallel to form a heat exchange circuit; including: If the ambient temperature is within a preset first ambient temperature range, controlling the coolant circuit to operate, and controlling the valve unit to make the battery circuit communicate with part of the coolant channels of the multi-channel heat exchanger, the battery circuit and the coolant circuit being connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so that heat exchange is performed through the multi-channel heat exchanger to cool the coolant of the battery circuit; at the same time, the power circuit flows through the air-liquid heat exchanger to dissipate heat from the coolant of the power circuit through the air-liquid heat exchanger; Or, if the ambient temperature is within a preset first ambient temperature range and the temperature of the battery device exceeds a safety threshold, controlling the coolant circuit to operate, and controlling the valve unit to make the battery circuit communicate with all the coolant channels of the multi-channel heat exchanger, the battery circuit and the coolant circuit being connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so that heat exchange is performed through the multi-channel heat exchanger to intensively cool the coolant of the battery circuit; at the same time, the power circuit flows through the air-liquid heat exchanger to dissipate heat from the coolant of the power circuit through the air-liquid heat exchanger; or, if the ambient temperature is higher than the upper limit of the preset first ambient temperature range or the power device temperature exceeds its rated temperature upper limit, control the refrigerant circuit to operate, and control the valve unit to make the battery circuit communicate with one of the coolant channels of the multi-channel heat exchanger, the battery circuit and the refrigerant circuit form a heat exchange circuit in parallel through the multi-channel heat exchanger to exchange heat through the multi-channel heat exchanger to cool the coolant of the battery circuit; at the same time, make the power circuit communicate with the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger, the coolant of the power circuit is cooled through the air-liquid heat exchanger, and the power circuit and the refrigerant circuit form a heat exchange circuit in parallel through the multi-channel heat exchanger to exchange heat through the multi-channel heat exchanger to strengthen the cooling of the coolant of the power circuit; in this process, the battery circuit and the power circuit are heat-isolated through the unconnected coolant channels of the multi-channel heat exchanger; or, if the ambient temperature is in the preset second ambient temperature range and the thermal management system load is lower than the load threshold, control the refrigerant circuit to stop operating, and control the valve unit to make the battery circuit communicate with part of the coolant channels of the multi-channel heat exchanger, and at the same time, make the power circuit communicate with the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger, the power circuit and the battery circuit form a heat exchange circuit in parallel through the multi-channel heat exchanger, the coolant of the power circuit is cooled through the air-liquid heat exchanger, and exchanges heat with the battery circuit through the multi-channel heat exchanger to cool the coolant of the battery circuit; or, if the ambient temperature is in the preset third ambient temperature range, control the refrigerant circuit to stop operating, control the air-liquid heat exchanger fan to be turned off, and control the valve unit to make the battery circuit communicate with part of the coolant channels of the multi-channel heat exchanger, and at the same time, make the power circuit communicate with the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger, the power circuit and the battery circuit form a heat exchange circuit in parallel through the multi-channel heat exchanger to exchange heat through the multi-channel heat exchanger to make the coolant of the power circuit and the coolant of the battery circuit transfer heat to each other to cool the power device and heat the battery device; or, if the ambient temperature is lower than a lower limit of a third preset ambient temperature range or the battery device temperature is lower than a minimum starting temperature, controlling the refrigerant circuit and the power circuit to stop running, and controlling the valve unit to make the battery circuit communicate with one of the coolant channels of the multi-channel heat exchanger, the battery circuit and the multi-channel heat exchanger being connected in series to form a heat exchange circuit dedicated to heating, and the battery device being heated and kept warm by heating the coolant of the battery circuit.

[0010] In a specific embodiment, the thermal management method further comprises: obtaining a current battery temperature of the battery pack in the battery pack branch; adjusting the opening degree of the control valve on the battery pack branch based on the difference between the current battery temperature and a target temperature and the working condition parameter, so that the heat exchange circuit communicates with the battery pack branch to perform thermal management on the battery pack; including: or, if the ambient temperature is lower than a lower limit of a third preset ambient temperature range or the battery device temperature is lower than a minimum starting temperature, controlling the refrigerant circuit and the power circuit to stop running, and controlling the valve unit to make the battery circuit communicate with one of the coolant channels of the multi-channel heat exchanger, the battery circuit and the multi-channel heat exchanger being connected in series to form a heat exchange circuit dedicated to heating, and the battery circuit and the battery pack branch being connected in parallel, and the battery device and the battery pack being heated and kept warm by heating the coolant of the battery circuit and the coolant of the battery pack branch; at this time, if the current battery temperature of the battery pack branch exceeds a heating target temperature, the opening degree of the control valve on the battery pack branch is reduced; if the current battery temperature of the battery pack branch is lower than the heating target temperature, the opening degree of the control valve corresponding to the battery pack branch is increased. if the ambient temperature is within the first ambient temperature range or the second ambient temperature range, controlling the refrigerant circuit to run, and controlling the valve unit to make the battery circuit communicate with part or all of the coolant channels of the multi-channel heat exchanger, the battery circuit and the battery pack branch being connected in parallel, and the battery circuit and the refrigerant circuit or the power circuit being connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so that the coolant of the battery circuit and the coolant of the battery pack branch are cooled by heat exchange through the multi-channel heat exchanger; at this time, if the current battery temperature of the battery pack branch exceeds a cooling target temperature, the opening degree of the control valve corresponding to the battery pack branch is increased; if the current battery temperature of the battery pack branch is lower than the cooling target temperature, the opening degree of the control valve corresponding to the battery pack branch is reduced.

[0011] In a specific embodiment, the thermal management method further comprises: acquire the internal temperature and humidity parameters of the power device in the power loop; based on the internal temperature and humidity parameters of the power device, control the throttling valve on the throttling branch to form a heat exchange loop in parallel with the throttling branch and the power loop to control the power device from condensation: If the internal temperature and humidity parameters of the power device reach the condensation risk threshold, control the throttling valve to form a heat exchange loop in parallel with the throttling branch and the power loop, part of the high-temperature cooling liquid at the outlet of the power device can flow directly to the throttling branch through the power loop, and the cooling liquid flowing directly to the inlet of the power device through the throttling branch mixes with the low-temperature cooling liquid in the power loop, and then flows to the inlet of the power device to increase the temperature of the cooling liquid flowing into the inlet of the power device.

[0012] A light storage device comprising the thermal management system as described above.

[0013] In summary, the beneficial technical effects of the present application: the multi-channel heat exchanger of the present application creates an integrated heat exchange core that can be dynamically configured through the unique flow channel arrangement of the refrigerant channels between the multiple cooling liquid channels; this structure not only achieves efficient heat exchange between the refrigerant and multiple cooling liquids, but more importantly, by controlling the opening and closing of specific cooling liquid channels through the valve unit, a thermal resistance layer composed of static fluid can be formed between adjacent channels, thereby physically solving the heat conduction problem between the battery loop (which requires low-temperature cooling) and the power loop (which requires relatively high-temperature cooling) caused by sharing the heat exchanger, and laying the foundation for realizing differentiated and precise temperature control. The thermal management system and method based on the above multi-channel heat exchanger integrates and schedules multiple thermal management methods such as refrigerant cooling, air cooling, liquid-liquid heat exchange, and electric heating through the intelligent reconstruction of the system flow path by the integrated valve unit; this system can provide an independent cooling path for the power device without interfering with the battery loop cooling under high-temperature conditions, and can achieve natural cooling or waste heat recovery without starting the refrigerant loop under medium and low-temperature conditions, and can safely heat the battery loop cooling liquid to preheat and maintain the temperature of the battery device under extreme low-temperature conditions, and always ensures the physical isolation of the power and battery double-loop fluids; making the system simultaneously achieve high reliability, high energy efficiency, and fine full-condition thermal management in a wide temperature range. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a structural schematic diagram of the multi-channel heat exchanger of the present application.

[0015] Figure 2 is a structural schematic diagram of the thermal management system of the present application.

[0016] Figure 3 is a structural schematic diagram for showing the parallel connection of the battery pack branch to the battery loop.

[0017] Figure 4 is a flow chart for illustrating temperature management of each battery pack branch.

[0018] Figure 5 is a structural diagram of a multi-channel heat exchanger in one embodiment.

[0019] Figure 6 is a structural diagram of a thermal management system in one embodiment.

[0020] Figure 7 is a structural diagram of a thermal management system when the ambient temperature is in a first ambient temperature range.

[0021] Figure 8 is a structural diagram of a thermal management system when the ambient temperature is in a first ambient temperature range and the battery temperature exceeds a safety threshold.

[0022] Figure 9 is a structural diagram of a thermal management system when the ambient temperature is higher than an upper limit of the first ambient temperature range or the power conversion device temperature exceeds an upper limit of its rated temperature.

[0023] Figure 10 is a structural diagram of a thermal management system when the ambient temperature is in a second ambient temperature range and the thermal management system load is lower than a load threshold.

[0024] Figure 11 is a structural diagram of a thermal management system when the ambient temperature is in a third ambient temperature range.

[0025] Figure 12 is a structural diagram of a thermal management system when the ambient temperature is in a lower limit of the third ambient temperature range and the battery temperature is lower than a minimum start-up temperature.

[0026] BRIEF DESCRIPTION OF REFERENCE NUMERALS: 1, multi-channel heat exchanger; 2, flow passage unit; 21, refrigerant passage; 22, coolant passage; 23, first coolant passage; 24, second coolant passage; 25, third coolant passage; 3, refrigerant circuit; 31, compressor; 32, regulating valve; 4, power circuit; 41, power device; 411, power conversion device; 412, first heat transfer device; 42, first pump; 5, battery circuit; 51, battery device; 511, battery; 512, second heat transfer device; 52, second pump; 53, heater; 6, air-liquid heat exchanger; 61, refrigerant side; 62, coolant side; 63, fan; 7, valve unit; 71, valve group; 72, three-way valve; 73, six-way valve; 8, battery pack branch; 81, battery pack; 82, control valve; 9, throttling branch; 91, throttle valve; C1, first port; C2, second port; C3, third port; C4, fourth port; C5, fifth port; C6, sixth port. Detailed Implementation

[0027] The following is in conjunction with the appendix Figures 1-12 This application will be described in further detail.

[0028] This application discloses a multi-channel heat exchanger that simultaneously, efficiently, and isolatedly handles the heat transfer of multiple fluids through an integrated heat exchange hub. It is particularly suitable for complex applications such as photovoltaic energy storage devices that require differentiated temperature control for batteries (low-temperature requirements) and power conversion devices (relatively high-temperature requirements).

[0029] Reference Figure 1 The multi-channel heat exchanger 1 includes multiple repeating flow channel units 2; each flow channel unit 2 includes a refrigerant channel 21 and multiple coolant channels 22, with the refrigerant channel 21 located between the multiple coolant channels 22; the multi-channel heat exchanger 1 creates a scalable standardized heat exchange unit, in which the refrigerant channel 21 is surrounded by multiple coolant channels 22. This layout allows a cold source (refrigerant channel 21) to exchange heat with multiple independent coolant channels 22 simultaneously, thus providing the physical possibility for building a centralized, efficient and configurable heat exchange core, and is the basis for realizing the topology of subsequent complex thermal management systems.

[0030] Reference Figure 2 This application also discloses a thermal management system that integrates the above-mentioned multi-channel heat exchanger 1; the system integrates various thermal management methods such as refrigerant refrigeration, air cooling, liquid-liquid heat exchange, waste heat recovery and active heating through ingenious topology and dynamic reconfiguration capability.

[0031] The thermal management system includes a multi-channel heat exchanger 1, a refrigerant circuit 3, a power circuit 4, a battery circuit 5, an air-liquid heat exchanger 6, and a valve unit 7.

[0032] The air-liquid heat exchanger 6 has a refrigerant side 61 and a coolant side 62. As a bidirectional environmental heat exchange interface, the air-liquid heat exchanger 6 has its refrigerant side 61 integrated into the refrigerant circuit 3 and its coolant side 62 connected in series with the power circuit 4, so that its role can be flexibly switched between condenser and air cooler.

[0033] The refrigerant circuit 3 includes the refrigerant side 61 of the air-liquid heat exchanger 6. The inlet and outlet of the refrigerant circuit 3 are connected to the refrigerant channel 21 of the multi-channel heat exchanger 1 through pipelines, respectively, to exchange heat with the battery circuit 5 and the power circuit 4, in order to cool the coolant of the battery circuit 5 and the coolant of the power circuit 4. By connecting the refrigerant side 61 of the air-liquid heat exchanger 6 to the refrigerant circuit 3 and connecting it to the refrigerant channel 21 of the multi-channel heat exchanger 1, the system can start the refrigerant circuit 3 for refrigeration cycle when needed, providing the system with the basic refrigeration capacity required to cope with high ambient temperature conditions and high heat loads, and ensuring the temperature safety of the core equipment.

[0034] The power circuit 4 comprises a power device 41, and the inlet end of the power circuit 4 is communicated with the valve unit 7 and the outlet of the cooling liquid side 62 of the air-liquid heat exchanger 6 through a pipeline, and the outlet end of the power circuit 4 is communicated with the inlet of the cooling liquid side 62 of the air-liquid heat exchanger 6 through a pipeline; the power circuit 4 can also be communicated with the cooling liquid channel 22 of the multi-channel heat exchanger 1 through the valve unit 7 to exchange heat with the refrigerant circuit 3 to cool the power device 41; the design provides a double and optional heat dissipation path for the power circuit 4; the basic path is to dissipate heat through the cooling liquid side 62 of the air-liquid heat exchanger 6, and the method has high energy efficiency in most low-temperature and low-load scenes; the enhanced path is to switch through the valve unit 7 to connect one cooling liquid channel 22 in the multi-channel heat exchanger 1 into the power circuit 4 to introduce the strong cooling capacity of the refrigerant circuit 3 for secondary cooling (supplementary cooling); the double-path design enhances the adaptability and reliability of the system to a wide temperature range and sudden overload working conditions.

[0035] The battery circuit 5 comprises a battery device 51, and the inlet end of the battery circuit 5 is communicated with the valve unit 7 and the outlet of the cooling liquid channel 22 of the multi-channel heat exchanger 1 through a pipeline, and the outlet end of the battery circuit 5 is communicated with the inlet of the cooling liquid channel 22 of the multi-channel heat exchanger 1 through a pipeline; the battery circuit 5 can be communicated with part or all of the cooling liquid channels 22 to exchange heat with the refrigerant circuit 3 to cool the battery device 51; the design provides a highly flexible and adjustable scheme for the thermal management of the battery circuit 5, and the battery circuit 5 is connected with the cooling liquid channels 22 of the multi-channel heat exchanger 1 through the valve unit 7, and can select to use part of the channels (basic cooling) or all of the channels (enhanced cooling) according to the heat dissipation requirement, so as to realize the thermal management coverage of the battery in the whole temperature range and the whole life cycle working condition.

[0036] The valve unit 7 comprises a valve group 71 and a three-way valve 72; the inlet end of the battery circuit 5 is communicated with the valve group 71 through a pipeline, and is communicated with the cooling liquid channels 22 of the multi-channel heat exchanger 1 through the valve group 71; the outlet end of the battery circuit 5 is communicated with the three-way valve 72 through a pipeline, and is communicated with the cooling liquid channels 22 of the multi-channel heat exchanger 1 through the three-way valve 72 to exchange heat with the refrigerant circuit 3 to cool the battery device 51; wherein two cooling liquid channels 22 can be connected in parallel into the battery circuit 5, and one of the two cooling liquid channels 22 can be used as a heat insulation channel between the battery circuit 5 and the power circuit 4; In practical applications, the three-way valve 72 is used to control the use strategy of the battery circuit 5 to the two parallel cooling liquid passages 22, and the configuration of parallel (increasing the heat exchange area) or single selection (reserving the heat insulation passage); the valve group 71 is used as the flow path distribution hub of the system, and the multiple ports thereof are connected with the key nodes of the system respectively; by changing the internal communication state thereof, the different cooling liquid passages 22 of the multi-pass heat exchanger 1 can be dynamically distributed to the power circuit 4 or the battery circuit 5, and the flow direction and the circuit topology of the cooling liquid can be changed; the programmable distribution and the dynamic thermal isolation functions of the flow path resource are realized, and the key foundation and the control means for solving the large temperature difference between the battery circuit 5 and the power circuit 4 and the resulting heat conduction problem are provided.

[0037] With reference to Figure 3 Further, the thermal management system further comprises the battery pack branch 8, the battery pack branch 8 comprising the battery pack 81 and the control valve 82, the inlet and outlet of the battery pack branch 8 being connected in parallel with the inlet and outlet of the battery circuit 5 through the pipelines, and the control valve 82 being used to adjust the flow of the cooling liquid on each battery pack branch 8, so as to balance the temperature of each battery pack branch 8; on the basis of the overall temperature control of the system main circuit to the battery system, by arranging the independent control valve 82 on each parallel battery pack branch 8, the system can adjust the cooling liquid flow through each battery pack 81 in real time and independently according to the temperature feedback signal of each battery pack 81; in this way, the cooling or heating is distributed on demand, which can effectively compensate for the uneven heat generation or dissipation caused by the position and internal resistance difference of the battery pack 81, so as to control the temperature difference of the entire battery system within an optimal range, and improve the consistency, safety and cycle life of the battery system. And / or, the thermal management system further comprises the throttling branch 9 (with reference to Figure 2 The throttling branch 9 comprises the throttling valve 91, and the inlet and outlet of the throttling branch 9 are connected with the outlet and inlet of the power device 41 through the pipelines; the throttling branch 9 can be connected in parallel with the power circuit 4, and exchanges heat with the power circuit 4, so as to increase the temperature of the cooling liquid at the inlet of the power device 41; by connecting the throttling branch 9 in parallel, a part of the cooling liquid with a relatively high temperature flowing out from the outlet of the power device 41 is not cooled through the main heat dissipation circuit (such as the air-liquid heat exchanger 6), but is directly returned to the inlet of the power device 41 through the throttling branch 9, and is mixed with the low-temperature cooling liquid of the main circuit; in this way, the temperature of the cooling liquid entering the inlet of the power device 41 can be rapidly and actively increased, so as to correspondingly increase the surface temperature of these components, so that the surface temperature is higher than the dew point temperature of the ambient air, the conditions for condensation are fundamentally eliminated, and the operation reliability and safety of the equipment in a humid and hot environment are enhanced.

[0038] With reference to Figures 2-4 Based on the foregoing thermal management system, the application further discloses an intelligent thermal management method corresponding thereto and used for driving the thermal management system; comprising the following steps: Obtaining the working condition parameters of the thermal management system, the working condition parameters including one or more of the ambient temperature, the power device temperature, the battery device temperature, the thermal management system load; based on the working condition parameters, controlling the working state of the valve unit 7, so that the series or parallel connection between the refrigerant circuit 3, the battery circuit 5 and the power circuit 4 to form a heat exchange circuit; The thermal management method intelligently calls the multiple flow path connection possibilities provided by the foregoing thermal management system architecture based on the working condition parameters, combines the optimal cooling, cold supplement or heating path in real time, realizes the transition from fixed cooling to on-demand cold supply, and thus realizes full-condition self-adaptation.

[0039] Based on different working condition parameter combinations, the valve unit 7 is controlled to form different heat exchange circuits; including: If the ambient temperature is within a preset first ambient temperature range, the refrigerant circuit 3 is controlled to operate, and the valve unit 7 is controlled to make the battery circuit 5 communicate with part of the cooling liquid channels 22 of the multi-channel heat exchanger 1, the battery circuit 5 and the refrigerant circuit 3 are connected in parallel through the multi-channel heat exchanger 1 to form a heat exchange circuit, so that heat exchange is performed through the multi-channel heat exchanger 1 to cool the cooling liquid of the battery circuit 5; at the same time, the power circuit 4 flows through the air-liquid heat exchanger 6 to dissipate heat through the air-liquid heat exchanger 6 to the cooling liquid of the power circuit 4; in this process, the battery circuit 5 and the power circuit 4 are completely physically isolated and operated in parallel, the cooling liquids of the battery circuit 5 and the power circuit 4 do not mix with each other, and the respective circuits are independently operated, avoiding mutual hydraulic and thermal interference caused by circuit series connection, improving the independence and long-term reliability of the operation of each circuit, and providing a guarantee for the basic stable operation of the system.

[0040] Or, if the ambient temperature is within a preset first ambient temperature range and the battery device temperature exceeds a safety threshold, the refrigerant circuit 3 is controlled to operate, and the valve unit 7 is controlled to make the battery circuit 5 communicate with all the cooling liquid channels 22 of the multi-channel heat exchanger 1, the battery circuit 5 and the refrigerant circuit 3 are connected in parallel through the multi-channel heat exchanger 1 to form a heat exchange circuit, so that heat exchange is performed through the multi-channel heat exchanger 1 to intensively cool the cooling liquid of the battery circuit 5; at the same time, the power circuit 4 flows through the air-liquid heat exchanger 6 to dissipate heat through the air-liquid heat exchanger 6 to the cooling liquid of the power circuit 4; in this process, by centrally allocating all the cooling liquid channels 22 in the multi-channel heat exchanger 1 to the battery circuit 5, the heat exchange area and the heat exchange amount of the battery circuit 5 and the refrigerant circuit 3 are maximized, so as to provide the battery circuit 5 with the maximum cooling capacity under the current conditions, and form a highest priority safety intervention mechanism for the potential thermal runaway risk of the battery device 51.

[0041] Or, if the ambient temperature is higher than the upper limit of the preset first ambient temperature range or the power device temperature exceeds its rated temperature upper limit, control the refrigerant circuit 3 to operate, and control the valve unit 7 to make the battery circuit 5 communicate with one of the coolant channels 22 of the multi-channel heat exchanger 1, and the battery circuit 5 and the refrigerant circuit 3 form a heat exchange circuit in parallel through the multi-channel heat exchanger 1 to exchange heat through the multi-channel heat exchanger 1 and cool the coolant of the battery circuit 5; at the same time, make the power circuit 4 communicate with the air-liquid heat exchanger 6 and another coolant channel 22 of the multi-channel heat exchanger 1, and the coolant of the power circuit 4 is cooled through the air-liquid heat exchanger 6, and the power circuit 4 and the refrigerant circuit 3 form a heat exchange circuit in parallel through the multi-channel heat exchanger 1 to exchange heat through the multi-channel heat exchanger 1 and strengthen the cooling of the coolant of the power circuit 4; at this time, the battery circuit 5 and the power circuit 4 are heat-isolated through the unconnected coolant channels 22 in the multi-channel heat exchanger 1; in this process, a dedicated coolant channel 22 is dynamically allocated for the power circuit 4 through the valve group 71 to obtain direct cooling from the refrigerant circuit 3, and the stationary working medium in an adjacent coolant channel 22 controlled to be in a closed state forms a high-efficiency thermal resistance layer; this scheme enables the cooling of the battery circuit 5 (which requires a lower temperature) and the cooling of the power circuit 4 (which requires a relatively higher temperature and needs to be strengthened) to be implemented in parallel in the same heat exchanger without interference, fundamentally solving the heat stringing problem caused by the large temperature difference of the cooling liquid required by the shared heat exchanger, and realizing differentiated and accurate temperature control.

[0042] Or, if the ambient temperature is in the preset second ambient temperature range and the thermal management system load is lower than the load threshold, control the refrigerant circuit 3 to stop operating, and control the valve unit 7 to make the battery circuit 5 communicate with part of the coolant channels 22 of the multi-channel heat exchanger 1, and at the same time make the power circuit 4 communicate with the air-liquid heat exchanger 6 and another coolant channel 22 of the multi-channel heat exchanger 1, and the power circuit 4 and the battery circuit 5 form a heat exchange circuit in parallel through the multi-channel heat exchanger 1, the coolant of the power circuit 4 is cooled through the air-liquid heat exchanger 6, and exchanges heat with the battery circuit 5 through the multi-channel heat exchanger 1 to cool the coolant of the battery circuit 5; in this process, by constructing a liquid-liquid heat exchange path between the power circuit 4 and the battery circuit 5 through the multi-channel heat exchanger 1, the power circuit 4 coolant cooled by the air-liquid heat exchanger 6 becomes an intermediate medium for transferring environmental cold energy, so that the heat dissipation requirements of the two circuits can be met simultaneously by using only the environmental natural cold source without starting the high-energy-consumption compressor 31 refrigeration system, significantly reducing the operating energy consumption of the system under suitable environmental conditions.

[0043] Or, if the ambient temperature is within a preset third ambient temperature range, the refrigerant circuit 3 is controlled to stop running, the fan 63 of the air-liquid heat exchanger 6 is controlled to be turned off, and the valve unit 7 is controlled to make the battery circuit 5 communicate with part of the cooling liquid channels 22 of the multi-channel heat exchanger 1, while making the power circuit 4 communicate with the air-liquid heat exchanger 6 and another cooling liquid channel 22 of the multi-channel heat exchanger 1, the power circuit 4 and the battery circuit 5 form a heat exchange circuit in parallel through the multi-channel heat exchanger 1 to exchange heat through the multi-channel heat exchanger 1, so that the cooling liquid of the power circuit 4 and the cooling liquid of the battery circuit 5 exchange heat with each other to cool the power device 41 and heat and keep warm the battery device 51; In this process, through the liquid-liquid heat exchange circuit, the waste heat generated by the power circuit 4 during operation is directed and controllably transferred to the battery circuit 5 to compensate for the heat lost to the outside world by the battery circuit 5 in a low-temperature environment; Thus, the effective recovery and reuse of low-grade heat within the system is realized, while meeting the battery warming demand with zero power consumption, it also assists the heat dissipation of the power circuit 4, achieving closed-loop efficient use of system-level energy.

[0044] Or, if the ambient temperature is lower than the lower limit of the preset third ambient temperature range or the battery device temperature is lower than the minimum starting temperature, the refrigerant circuit 3 and the power circuit 4 are controlled to stop running, and the valve unit 7 is controlled to make the battery circuit 5 communicate with one of the cooling liquid channels 22 of the multi-channel heat exchanger 1, and the battery circuit 5 and the multi-channel heat exchanger 1 form a heating dedicated heat exchange circuit in series to heat and keep warm the battery device 51 by heating the cooling liquid of the battery circuit 5; In this process, the system only operates the independent circulation configured for heating the battery device 51, and actively heats the cooling liquid to provide the battery device 51 with the heat required for starting or maintaining its chemical activity, which is a basic heat guarantee measure to ensure that the battery device 51 can be normally activated and safely operated in an extremely low-temperature environment.

[0045] Referring to Figure 3 and Figure 4 , for a system including a plurality of battery packs 81, the thermal management method further includes fine thermal management of the battery packs 81: obtaining the current battery temperature (denoted as Ti) of the battery pack 81 in the battery pack branch 8; based on the difference between the current battery temperature (Ti) and the target temperature, and the working condition parameters, adjusting the opening of the control valve 82 on the battery pack branch 8, so that the heat exchange circuit communicates with the battery pack branch 8 to perform thermal management on the battery pack 81; Specifically including: If the ambient temperature is lower than the lower limit of the preset third ambient temperature range or the battery device temperature is lower than the minimum starting temperature, the control power circuit 4 and the refrigerant circuit 3 are stopped, the valve unit 7 is controlled to make the battery circuit 5 communicate with one of the coolant channels 22 of the multi-channel heat exchanger 1, the battery circuit 5 and the multi-channel heat exchanger 1 form a heating dedicated heat exchange circuit in series, and the battery circuit 5 and the battery pack branch 8 are connected in parallel, so that the battery device 51 and the battery pack 81 are heated and kept warm by heating the coolant in the battery circuit 5 and the coolant in the battery pack branch 8. At this time, if the current battery temperature (Ti) of the battery pack branch 8 exceeds the heating target temperature, the opening of the control valve 82 on the battery pack branch 8 is reduced; otherwise, the opening of the control valve 82 on the corresponding battery pack branch 8 is increased; in this process, the working fluid flow of each battery pack branch 8 is dynamically adjusted according to the deviation of the real-time temperature of each battery pack 81 from the set target, so as to realize fine on-demand distribution of heating power of each battery pack 81 in the battery system, thereby ensuring uniform temperature rise of the entire battery system during preheating or keeping warm, avoiding local overheating or insufficient heating, optimizing heating efficiency and ensuring battery safety.

[0046] If the ambient temperature is in the first ambient temperature range or the second ambient range, the refrigerant circuit 3 is controlled to operate, and the valve unit 7 is controlled to make the battery circuit 5 communicate with part or all of the coolant channels 22 of the multi-channel heat exchanger 1, the battery circuit 5 and the battery pack branch 8 are connected in parallel, and the battery circuit 5 and the refrigerant circuit 3 or the power circuit 4 are connected in parallel through the multi-channel heat exchanger 1 to form a heat exchange circuit, so as to exchange heat through the multi-channel heat exchanger 1 and cool the coolant in the battery circuit 5 and the coolant in the battery pack branch 8. At this time, if the current battery temperature (Ti) of the battery pack branch 8 exceeds the target temperature, the opening of the control valve 82 on the corresponding battery pack branch 8 is increased; otherwise, the opening of the control valve 82 on the corresponding battery pack branch 8 is reduced; in this process, the coolant flow is accurately distributed according to the actual thermal load of each battery pack 81, so that the battery pack 81 with larger thermal load obtains more cold energy, and the battery pack 81 with smaller thermal load avoids overcooling, thereby realizing fine temperature management among the battery packs 81 on the basis of system-level cooling, and ensuring thermal safety and performance uniformity of the battery system during high-temperature or high-rate operation.

[0047] Referring to Figure 2 The thermal management method further includes anti-condensation control of the power device 41, which includes: obtaining the internal temperature and humidity parameters of the power device 41 in the power circuit 4; based on the internal temperature and humidity parameters of the power device 41, the throttle valve 91 on the throttling branch 9 is controlled to make the power circuit 4 and the throttling branch 9 form a heat exchange circuit in parallel, so as to perform anti-condensation control on the power device 41; If the internal temperature and humidity parameters of the power device 41 reach the condensation risk threshold, the control valve 91 is controlled to make the throttling branch 9 and the power circuit 4 parallel to form a heat exchange circuit. Part of the high-temperature cooling liquid at the outlet of the power device 41 can flow directly to the throttling branch 9 through the power circuit 4, and then directly to the inlet of the power device 41 through the throttling branch 9, so as to increase the temperature of the cooling liquid flowing into the inlet of the power device 41. In this process, the temperature of the cooling liquid flowing into the internal heat exchange component of the power device 41 is rapidly and directly increased by actively short-circuiting part of the high-temperature cooling liquid at the outlet of the power device 41 and mixing it with the low-temperature cooling liquid before the inlet. This causes the surface temperature of the electrical components in contact with the cooling liquid to increase accordingly, thereby ensuring that it is stably higher than the dew point temperature of the current ambient air, actively eliminating the possibility of condensation from a physical condition, and enhancing the operation reliability and electrical safety of the power device 41 in a humid environment.

[0048] To enable those skilled in the art to more clearly understand the specific implementation modes of the present application, the following will be further detailed and expanded in conjunction with the accompanying drawings. Figures 5-12 The internal structure of the multi-channel heat exchanger 1, the connection relationship between the components of the thermal management system, and the detailed execution process of the thermal management method under different working conditions will be further detailed and expanded by a specific embodiment.

[0049] Referring to Figure 5 In a specific embodiment, the structure of the multi-channel heat exchanger 1 is specifically as follows: The specific form of the multi-channel heat exchanger 1 includes but is not limited to a plate heat exchanger or a tube-fin heat exchanger. In this embodiment, the plate heat exchanger is taken as an example. The multi-channel heat exchanger 1 is formed by repeatedly arranging a plurality of identical flow channel units 2 in the stacking direction of the plates, so as to flexibly expand the heat exchange area according to the heat exchange requirement and adapt to the equipment requirements of different power levels. In this embodiment, each flow channel unit 2 includes four channels isolated from each other, specifically including a first cooling liquid channel 23, a refrigerant channel 21, a second cooling liquid channel 24, and a third cooling liquid channel 25 arranged in sequence. In this embodiment, the refrigerant channel 21 is used for flowing refrigerant, and the first cooling liquid channel 23 is used as a switchable intermediate cooling liquid channel 22. The second cooling liquid channel 24 and the third cooling liquid channel 25 are configured to be able to be connected in parallel through an external three-way valve 72. The cooling liquid can be water, glycol solution, or other applicable heat-conducting working medium, and the refrigerant can be common refrigerants such as R410A, R134A, and R32.

[0050] In practical applications, the physical isolation of the four channels ensures that the refrigerant does not mix with at least two cooling liquids; and the unique sequential arrangement of the four channels, combined with the controllable parallel design of the second cooling liquid channel 24 and the third cooling liquid channel 25, creates a dynamic thermal isolation mechanism; for example, when the high-temperature power conversion device (flowing through the first cooling liquid channel 23) and the low-temperature battery (flowing through the second cooling liquid channel 24) need to be cooled simultaneously and heat exchange needs to be avoided, the third cooling liquid channel 25 can be closed; at this time, the fluid in the third cooling liquid channel 25 flows at a low speed or is static, and due to its extremely low convective heat transfer efficiency, it forms a static thermal barrier between the first cooling liquid channel 23 and the second cooling liquid channel 24, thereby solving the problem of heat exchange between the battery and the power conversion device in the traditional solution.

[0051] Reference Figure 6 In a specific embodiment, based on the above-mentioned multi-channel heat exchanger 1, the specific implementation of each component of the thermal management system is as follows: In a specific embodiment of the air-liquid heat exchanger 6, it further includes a fan 63, and the refrigerant side 61 is integrated into the refrigerant circuit 3, and the cooling liquid side 62 is connected in series in the power circuit 4.

[0052] The refrigerant circuit 3 specifically includes a compressor 31, an air-liquid heat exchanger 6 refrigerant side 61, and a regulating valve 32 connected in series by pipelines; the inlet end (compressor 31 suction port) and the outlet end (regulating valve 32 outlet) of the air-liquid heat exchanger 6 are respectively connected to the outlet and inlet of the refrigerant channel 21 of the multi-channel heat exchanger 1 by pipelines, thereby forming a closed loop; when the refrigerant circuit 3 is working, the refrigerant evaporates in the refrigerant channel 21, absorbs the heat of the cooling liquid flowing through the first cooling liquid channel 23, the second cooling liquid channel 24, and the third cooling liquid channel 25, flows out of the refrigerant channel 21, is compressed by the compressor 31, enters the air-liquid heat exchanger 6 refrigerant side 61, condenses, and releases heat to the environment air, thereby constituting the main heat source of the thermal management system to deal with high heat load.

[0053] The power device 41 in the power loop 4 specifically includes a power conversion device 411 and its first heat transfer device 412 (such as a liquid cooling plate). The power loop 4 also adds a first pump 42. The specific pipeline connection relationship is as follows: the outlet of the power conversion device 411 and its first heat transfer device 412, the coolant side 62 of the air-liquid heat exchanger 6, one side flow channel of the six-way valve 73, the first pump 42, and finally the return to the inlet of the power conversion device 411 and its first heat transfer device 412, forming a closed loop. The power loop 4 can also be connected to the first coolant channel 23 of the multi-channel heat exchanger 1 through the six-way valve 73. Specifically, by switching the six-way valve 73, the power loop 4 can connect the first coolant channel 23 of the multi-channel heat exchanger 1 in series into its own circulation loop. After the coolant flows through the six-way valve 73, it can be guided to the first coolant channel 23, where it undergoes secondary heat exchange (make-up cooling) with the refrigerant loop 3 to enhance the cooling of the power conversion device 411.

[0054] The battery device 51 in the battery circuit 5 specifically includes a battery 511 and its second heat transfer device 512 (including but not limited to a liquid cooling plate or an immersion cooling plate). The battery circuit 5 also adds a second pump 52 and a heater 53. The specific pipeline connection relationship is as follows: the outlet of the battery 511 and its second heat transfer device 512, the heater 53, the three-way valve 72, the second coolant channel 24 and / or the third coolant channel 25 of the multi-channel heat exchanger 1, the second pump 52, the valve group 71, and finally the return to the inlet of the heat transfer device of the battery 511, forming a closed loop to realize basic heat exchange. The battery circuit 5 can also be connected to the first coolant channel 23 of the multi-channel heat exchanger 1 through the valve group 71. Specifically, by switching the valve group 71, the battery circuit 5 can connect the first coolant channel 23 of the multi-channel heat exchanger 1 in series into its own circulation loop. After the coolant flows through the valve group 71, it can be guided to the first coolant channel 23, where it undergoes secondary heat exchange with the refrigerant circuit 3 to enhance the cooling of the battery 511.

[0055] In the battery circuit 5, one port of the three-way valve 72 is connected to the battery circuit 5, and the other two ports are connected to the second coolant passage 24 and the third coolant passage 25, respectively. By controlling the three-way valve 72, the second coolant passage 24 and the third coolant passage 25 can be connected in parallel. This allows the battery circuit 5 to selectively flow through both the second coolant passage 24 and the third coolant passage 25 simultaneously to increase the heat exchange area, or to flow through only the second coolant passage 24. When only the second coolant passage 24 is used, the fluid in the stationary third coolant passage 25 will form an effective thermal resistance layer.

[0056] In a specific embodiment of the valve unit 7, the valve group 71 is a six-way valve 73, and the connection relationship of the six ports (first port C1, second port C2, third port C3, fourth port C4, fifth port C5, and sixth port C6) of the six-way valve 73 is as follows: the first port C1 is connected to the outlet of the cooling liquid side 62 of the heat exchanger 6; the second port C2 is connected to the inlet of the first pump 42; the third port C3 is connected to the outlet of the battery 511 and the second heat transfer device 512 (i.e., the main loop return point of the battery circuit 5); the fourth port C4 is connected to the outlet of the second pump 52 (i.e., the main loop output point of the battery circuit 5); the fifth port C5 and the sixth port C6 are respectively connected to the inlet end and the outlet end of the first cooling liquid passage 23; by controlling the rotation of the valve core inside the six-way valve 73 to different working positions, the communication relationship between the above six ports can be changed, so as to dynamically reconstruct the connection topology of the power circuit 4, the battery circuit 5, and the passages of the multi-passage heat exchanger 1 at the hardware level, which is the basis for realizing the following multiple intelligent thermal management modes.

[0057] In a specific embodiment, the operation control mode of the thermal management system includes but is not limited to manual control and controller-based automatic control (intelligent control), and the embodiment takes the controller automatic control as an example; the system is provided with a monitoring module including various sensors for monitoring the ambient temperature, device temperature, humidity, and system load; the controller is electrically connected with all the sensors and each execution component to form a closed-loop control system; the controller can automatically judge and drive the system to switch to the corresponding heat exchange circuit according to the real-time working condition parameters; further, for a system including multiple battery packs 81, the controller can run the battery pack 81 uniform temperature control in parallel, and realize the fine and balanced control of the temperature of each battery pack 81 by adjusting the opening degree of the control valve 82 on each battery pack branch 8; correspondingly, the controller can run the anti-condensation control of the power conversion device 411 in parallel, and realize the anti-condensation by controlling the opening and closing of the throttle valve 91 on the throttle branch 9 to improve the cooling liquid temperature at the inlet of the power conversion device 411.

[0058] The following will be described in detail Figures 6-12 With the foregoing specific thermal management system structure as an embodiment, how the thermal management method is specifically executed to build and run multiple heat exchange circuits under different typical working condition parameters will be described in detail. It should be noted that, Figures 7-12 the dashed line represents the unconnected, stopped running, or closed state, and the solid line represents the connected, normally running, or open state, Figures 7-12 the arrow direction on each circuit represents the circulating direction of the circuit.

[0059] Referring to Figure 7If the ambient temperature is in a preset first ambient temperature range, in this embodiment, the first temperature range is 5℃ to 45℃; at this time, the ambient temperature is moderate and high, and the battery 511 and the power conversion device 411 are in the rated power charging and discharging state.

[0060] The controller starts the operation of the refrigerant circuit 3, and controls the system to enter the refrigeration state; the controller starts the operation of the fan 63 of the air-liquid heat exchanger 6, controls the heater 53 to be closed, and controls the first pump 42 and the second pump 52 to be started; and the controller controls the six-way valve 73 to be in the first position, in which the first port C1 and the second port C2 of the six-way valve 73 are communicated, the third port C3 and the fourth port C4 are communicated, and the fifth port C5 and the sixth port C6 are not working, so that the first cooling liquid passage 23 is in the bypass state; at the same time, the controller controls the three-way valve 72 of the battery circuit 5, so that the cooling liquid flows through the second cooling liquid passage 24 and the third cooling liquid passage 25 in parallel.

[0061] At this time, the power circuit 4 and the cooling liquid side 62 of the air-liquid heat exchanger 6 are connected in series to form an independent heat dissipation circuit, which dissipates heat of the cooling liquid of the power circuit 4; in operation, the cooling liquid of the power circuit 4 is circulated under the drive of the first pump 42, and the circulation starts from the outlet of the power conversion device 411 and the first heat transfer device 412 thereof, flows through the cooling liquid side 62 of the air-liquid heat exchanger 6, and is cooled by the ambient air; after being cooled, the cooling liquid flows into the six-way valve 73 from the first port C1, and directly flows out from the second port C2 due to the communication between the first port C1 and the second port C2; then, the cooling liquid is pressurized by the first pump 42, and returns to the inlet of the power conversion device 411 and the first heat transfer device 412 thereof, to complete the circulation and cool the power conversion device 411.

[0062] The battery circuit 5 is connected with the second cooling liquid passage 24 and the third cooling liquid passage 25 of the multi-channel heat exchanger 1, and the battery circuit 5 and the refrigerant circuit 3 form a heat exchange circuit in parallel through the multi-channel heat exchanger 1, which cools the cooling liquid of the battery circuit 5; in operation, the cooling liquid of the battery circuit 5 is circulated under the drive of the second pump 52, and the circulation starts from the outlet of the battery 511 and the second heat transfer device 512 thereof; the cooling liquid flows through the heater 53 (which is not working at this time) and the three-way valve 72; then, the cooling liquid is divided into two streams, and enters the second cooling liquid passage 24 and the third cooling liquid passage 25 of the multi-channel heat exchanger 1; in the two passages, the cooling liquid exchanges heat with the refrigerant circuit 3 and is cooled; the two streams of the cooled cooling liquid are combined, pressurized by the second pump 52, and flow into the six-way valve 73 from the fourth port C4; due to the communication between the third port C3 and the fourth port C4, the cooling liquid directly flows out from the third port C3; then, the cooling liquid returns to the inlet of the battery 511 and the second heat transfer device 512 thereof, to complete the circulation and cool the battery 511.

[0063] The refrigerant in the refrigerant circuit 3 performs a refrigeration cycle according to the refrigerant passage 21 of the multi-pass heat exchanger 1, the compressor 31, the refrigerant side 61 of the air-liquid heat exchanger 6, the regulating valve 32, and the refrigerant passage 21 of the multi-pass heat exchanger 1; the refrigerant evaporates in the refrigerant passage 21 and mainly absorbs the heat of the coolant of the battery circuit 5 from the adjacent second coolant passage 24 and third coolant passage 25.

[0064] With reference to Figure 8 If the ambient temperature is within a preset first ambient temperature range (5-45℃) and the battery temperature exceeds a safety threshold (for example, >45℃).

[0065] The controller starts the refrigerant circuit 3 to operate, so that the system enters a refrigeration state; controls the start of the fan 63 of the air-liquid heat exchanger 6, controls the closing of the heater 53, and controls the start of the first pump 42 and the second pump 52 to operate; and switches the six-way valve 73 to the second station, in which the fourth port C4 and the fifth port C5 of the six-way valve 73 are communicated, and the sixth port C6 and the third port C3 are communicated; thereby forming a series circuit including the second coolant passage 24 and the third coolant passage 25, the fourth port C4, the fifth port C5, the first coolant passage 23, the sixth port C6, and the third port C3; the first port C1 and the second port C2 remain communicated; at the same time, the three-way valve 72 of the battery circuit 5 is controlled to make the coolant flow in parallel through the second coolant passage 24 and the third coolant passage 25.

[0066] At this time, the power circuit 4 and the coolant side 62 of the air-liquid heat exchanger 6 are in series to form an independent heat dissipation circuit for dissipating heat from the coolant of the power circuit 4; in operation, the coolant of the power circuit 4 circulates under the drive of the first pump 42, and the circulation starts from the outlet of the power conversion device 411 and the first heat transfer device 412 thereof, flows through the coolant side 62 of the air-liquid heat exchanger 6 and is cooled by the ambient air; after cooling, the coolant enters the six-way valve 73 from the first port C1 and directly flows out from the second port C2 due to the communication between the first port C1 and the second port C2; then, the coolant is pressurized by the first pump 42 and returns to the inlet of the power conversion device 411 and the first heat transfer device 412 thereof to complete the circulation and achieve the cooling of the power conversion device 411.

[0067] The battery circuit 5 is in communication with the first cooling liquid passage 23, the second cooling liquid passage 24 and the third cooling liquid passage 25 of the multi-pass heat exchanger 1, and the battery circuit 5 and the refrigerant circuit 3 form a heat exchange circuit in parallel through the multi-pass heat exchanger 1 to intensively cool the cooling liquid of the battery circuit 5; in operation, the cooling liquid of the battery circuit 5 flows out of the battery 511 and the second heat transfer device 512 thereof, passes through the heater 53 (not in operation at this time) and the three-way valve 72, and then flows in parallel through the second cooling liquid passage 24 and the third cooling liquid passage 25 of the multi-pass heat exchanger 1 to be cooled for the first time, and the cooling liquid is cooled by heat exchange with the refrigerant circuit 3; the two streams of fluid after being cooled are combined, pressurized by the second pump 52, and then flow into the six-way valve 73 from the fourth port C4, flow out of the fifth port C5 due to the communication between the fourth port C4 and the fifth port C5, and then flow into the first cooling liquid passage 23 of the multi-pass heat exchanger 1, where the cooling liquid is cooled for the second time by heat exchange with the refrigerant circuit 3; after flowing out of the first cooling liquid passage 23, the cooling liquid flows into the six-way valve 73 from the sixth port C6, and finally flows back to the battery 511 and the second heat transfer device 512 thereof from the third port C3 due to the internal circuit formed by the sixth port C6 and the third port C3, to complete the circulation and achieve the intensive cooling of the battery 511.

[0068] The refrigerant circuit 3 performs a refrigeration cycle as described above to absorb the heat from the cooling liquid of the battery circuit 5 in the first cooling liquid passage 23, the second cooling liquid passage 24 and the third cooling liquid passage 25 adjacent to the refrigerant circuit 3, thereby intensively cooling the cooling liquid of the battery circuit 5.

[0069] With reference to Figure 9 , if the ambient temperature is higher than the upper limit of the first ambient temperature range (> 45℃) or the power conversion device temperature exceeds the upper limit of its rated temperature (e.g. > 45℃).

[0070] The controller starts the operation of the refrigerant circuit 3 to put the system into a refrigeration state, starts the operation of the fan 63 of the air-liquid heat exchanger 6, controls the heater 53 to be turned off, and starts the operation of the first pump 42 and the second pump 52; and controls the six-way valve 73 to be switched to the third position, in which the first port C1 and the fifth port C5 of the six-way valve 73 are in communication, the sixth port C6 and the second port C2 are in communication, and the third port C3 and the fourth port C4 are in communication; at the same time, the controller controls the three-way valve 72 on the battery circuit 5 to close the path to the third cooling liquid passage 25, so that the cooling liquid of the battery 511 only flows through the second cooling liquid passage 24.

[0071] Power circuit 4 is connected in series with the coolant side 62 of air-liquid heat exchanger 6. Simultaneously, power circuit 4 is connected to the first coolant channel 23 of multi-channel heat exchanger 1, and forms a heat exchange circuit with refrigerant circuit 3 via multi-channel heat exchanger 1, allowing heat exchange through multi-channel heat exchanger 1 to enhance cooling of the coolant in power circuit 4. During operation, the coolant in power circuit 4 flows out from the outlet of power conversion device 411 and its first heat transfer device 412, undergoes initial cooling via the coolant side 62 of air-liquid heat exchanger 6, and then enters the six-way valve 73 from the first port C1. Port C1 is connected to the fifth port C5. The liquid flows out from the fifth port C5 and enters the first coolant channel 23 of the multi-channel heat exchanger 1. It undergoes secondary deep heat exchange (make-up cooling) with the refrigerant circuit 3 in the first coolant channel 23. After flowing out of the first coolant channel 23, it enters the six-way valve 73 from the sixth port C6. Since the sixth port C6 is connected to the second port C2, it flows out from the second port C2. Then, it is pressurized by the first pump 42 and returns to the inlet of the power conversion device 411 and its first heat transfer device 412 to complete the cycle and achieve enhanced cooling of the power conversion device 411.

[0072] Battery circuit 5 is only connected to the second coolant channel 24 of multi-channel heat exchanger 1, and forms a heat exchange circuit with refrigerant circuit 3 through multi-channel heat exchanger 1 to exchange heat and cool the coolant of battery circuit 5. During operation, the coolant of battery circuit 5 flows out from the outlet of battery 511 and its second heat transfer device 512, passes through heater 53 (which is not working at this time) and three-way valve 72, and then flows only through the second coolant channel 24 of multi-channel heat exchanger 1, where it exchanges heat with refrigerant circuit 3. After flowing out of the second coolant channel 24, it is pressurized by the second pump 52 and enters six-way valve 73 from the fourth port C4. Since the third port C3 and the fourth port C4 are connected, it flows out from the third port C3 and returns to the inlet of battery 511 and its second heat transfer device 512 to complete the cycle and achieve cooling of battery 511.

[0073] During this process, the third coolant passage 25 is closed ( Figure 4 (Middle dashed line) The internal fluid is stationary, forming a thermal resistance between the first coolant channel 23 and the second coolant channel 24, effectively preventing heat transfer between the coolant in the battery circuit 5 and the coolant in the power circuit 4.

[0074] Reference Figure 10 If the ambient temperature is within a preset second ambient temperature range and the load of the thermal management system is lower than a preset load threshold (e.g., <70% of the rated load), in this embodiment, the second ambient temperature range is -5℃ to 5℃.

[0075] The controller controls the compressor 31 to stop, controls the fan 63 of the air-liquid heat exchanger 6 to start, controls the heater 53 to stop, and controls the first pump 42 and the second pump 52 to start; the six-way valve 73 is switched to the fourth position, in which the first port C1 and the sixth port C6 of the six-way valve 73 are communicated, the fifth port C5 and the second port C2 are communicated, and the third port C3 and the fourth port C4 are communicated; at the same time, the three-way valve 72 is controlled to make the cooling liquid of the battery circuit 5 flow through the second cooling liquid passage 24 and the third cooling liquid passage 22 at the same time.

[0076] The battery circuit 5 is communicated with the second cooling liquid passage 24 and the third cooling liquid passage 25 of the multi-pass heat exchanger 1, the power circuit 4 is communicated with the first cooling liquid passage 23 of the multi-pass heat exchanger 1 and the cooling liquid side 62 of the air-liquid heat exchanger 6, and the battery circuit 5 and the power circuit 4 form parallel heat exchange circuits through the multi-pass heat exchanger 1; the cooling liquid of the power circuit 4 is cooled through the air-liquid heat exchanger 6 and exchanges heat with the cooling liquid of the battery circuit 5 through the multi-pass heat exchanger 1 to cool the cooling liquid of the battery circuit 5.

[0077] In operation, the cooling liquid of the power circuit 4 is circulated under the drive of the first pump 42, and the circulation starts from the outlet of the power conversion device 411 and the first heat transfer device 412, flows through the cooling liquid side 62 of the air-liquid heat exchanger 6 and is cooled by the ambient air; after being cooled, the cooling liquid flows into the first port C1 of the six-way valve 73 and flows out from the sixth port C6 due to the communication between the first port C1 and the sixth port C6; then, the cooling liquid enters the first cooling liquid passage 23 of the multi-pass heat exchanger 1; in the passage, the cooling liquid absorbs heat from the second cooling liquid passage 24 and the third cooling liquid passage 25 (the heat comes from the battery circuit 5) and flows out from the fifth port C5 into the six-way valve 73 and flows out from the second port C2 due to the communication between the fifth port C5 and the second port C2; finally, the cooling liquid is pressurized by the first pump 42 and returns to the inlet of the power conversion device 411 and the first heat transfer device 412 to complete the circulation and cool the power conversion device 411; The cooling liquid of the battery circuit 5 is circulated under the drive of the second pump 52, and the circulation starts from the battery 511 and the outlet of the second heat transfer device 512 thereof, flows through the heater 53 (not working at this time) and the three-way valve 72, is then branched, and enters the second cooling liquid channel 24 and the third cooling liquid channel 25 of the multi-channel heat exchanger 1 in parallel; in the channels, the cooling liquid releases the heat generated by the battery 511 to the cooling liquid of the power circuit 4 flowing through the first cooling liquid channel 23 through the partition wall, is cooled, is pressurized by the second pump 52 after cooling, enters the six-way valve 73 from the fourth port C4, directly flows out from the third port C3 due to the communication between the third port C3 and the fourth port C4, and then returns to the inlet of the battery 511 and the second heat transfer device 512 thereof, to complete the circulation and realize the cooling of the battery 511; in the heat exchange circuit, the heat of the battery 511 and the power conversion device 411 is finally collected by the power circuit 4 and dissipated to the external low-temperature environment by the air-liquid heat exchanger 6.

[0078] With reference to Figure 11 If the ambient temperature is in a preset third ambient temperature range, in this embodiment, the third ambient temperature range is -10℃ to -5℃.

[0079] The controller completely closes the refrigerant circuit 3 (the compressor 31 is stopped), controls the air fan 63 of the air-liquid heat exchanger 6 to be closed, controls the heater 53 to be closed, and controls the first pump 42 and the second pump 52 to be started; the six-way valve 73 is switched to the fourth position, in which the first port C1 and the sixth port C6 of the six-way valve 73 are communicated, the fifth port C5 and the second port C2 are communicated, and the third port C3 and the fourth port C4 are communicated; at the same time, the three-way valve 72 is controlled to make the cooling liquid of the battery circuit 5 flow through the second cooling liquid channel 24 and the third cooling liquid channel 22 at the same time.

[0080] The battery circuit 5 is communicated with the second cooling liquid channel 24 and the third cooling liquid channel 25 of the multi-channel heat exchanger 1, the power circuit 4 is communicated with the first cooling liquid channel 23 of the multi-channel heat exchanger 1 and the cooling liquid side 62 of the air-liquid heat exchanger 6, and the battery circuit 5 and the power circuit 4 form a parallel heat exchange circuit through the multi-channel heat exchanger 1; the cooling liquid of the battery circuit 5 and the cooling liquid of the power circuit 4 exchange heat with each other through the partition wall in the multi-channel heat exchanger 1, to cool the power conversion device 411 and heat and keep warm the battery 511.

[0081] When working, the coolant of the power circuit 4 is circulated under the drive of the first pump 42, and the circulation starts from the outlet of the power conversion device 411 and the first heat transfer device 412 thereof, and the coolant flows through the air-liquid heat exchanger 6, and then enters the sixth port C6 of the six-way valve 73 from the first port C1, and flows out from the sixth port C6 into the first coolant channel 23 of the multi-channel heat exchanger 1; in the channel, the coolant releases the heat generated by the power conversion device 411 to the coolant of the battery circuit 5 flowing through the second coolant channel 24 and the third coolant channel 25, and is cooled itself, and after being cooled, enters the second port C2 of the six-way valve 73 from the fifth port C5, and flows out from the second port C2; finally, the coolant is pressurized by the first pump 42, and returns to the inlet of the power conversion device 411 and the first heat transfer device 412 thereof, to complete the circulation, so as to cool the power conversion device 411; The coolant of the battery circuit 5 is circulated under the drive of the second pump 52, and the circulation starts from the outlet of the battery 511 and the second heat transfer device 512 thereof, and the coolant flows through the heater 53 (which is not working at this time) and the three-way valve 72; then, the coolant is divided into two streams, and enters the second coolant channel 24 and the third coolant channel 25 of the multi-channel heat exchanger 1 in parallel; in the channels, the coolant absorbs the heat from the coolant of the power circuit 4 flowing through the first coolant channel 23, and flows out, is pressurized by the second pump 52, and enters the third port C3 of the six-way valve 73 from the fourth port C4, and flows out directly from the third port C3, and then returns to the inlet of the battery 511 and the second heat transfer device 512 thereof, to complete the circulation, so as to heat and keep warm the battery 511. In the circuit, the waste heat generated by the working power conversion device 411 increases the temperature of the coolant of the power circuit 4, and when the coolant of the power circuit 4 flows through the first coolant channel 23, the coolant transfers the heat to the coolant of the battery circuit 5 flowing through the second coolant channel 24 and the third coolant channel 25 through the partition wall; thus, the waste heat of the power conversion device 411 is transferred to the battery circuit 5, to keep warm the battery 511, and to cool the power conversion device 411 itself; the air-liquid heat exchanger 6 only plays a role of fluid communication in the process.

[0082] With reference to Figure 12 , if the ambient temperature is lower than the lower limit of the third ambient temperature range (<-10℃) or the battery temperature is lower than the minimum starting temperature (for example, <0℃); In the sixth mode, the controller stops the refrigerant circuit 3, the power circuit 4 and the first pump 42 completely; controls to close the fan 63 of the air-liquid heat exchanger 6; switches the six-way valve 73 to the fifth position, in which the fourth port C4 and the third port C3 of the six-way valve 73 are communicated, and the connection between the remaining ports is closed, only enabling the battery circuit 5 to circulate independently; at the same time, the heater 53 of the battery circuit 5 is started and the second pump 52 is turned on, and the three-way valve 72 is controlled to make the coolant flow through one of the second coolant passage 24 or the third coolant passage 25 (reducing the heat dissipation surface).

[0083] The battery circuit 5 is connected in series with the heater 53 to form a dedicated heat exchange circuit for heating, and the heater 53 is controlled to heat the coolant of the battery circuit 5 to heat and keep warm the battery 511; the power circuit 4, the air-liquid heat exchanger 6 and the first coolant passage 23 of the multi-channel heat exchanger 1 are all not involved in work.

[0084] In operation, the coolant of the battery circuit 5 forms an independent heating cycle under the drive of the second pump 52, The cycle starts at the outlet of the battery 511 and the second heat transfer device 512, and the coolant is directly heated by flowing through the heater 53; then it is guided by the three-way valve 72 to flow through only one of the second coolant passage 24 or the third coolant passage 25 of the multi-channel heat exchanger 1, and after flowing out, it is pressurized by the second pump 52 and enters the six-way valve 73 from the fourth port C4, because the fourth port C4 and the third port C3 are communicated, it flows out from the third port C3, and finally returns to the inlet of the battery 511 and the second heat transfer device 512, continuously providing preheating heat for the battery 511 module.

[0085] Referring to Figure 3 , 4 , 6, in a specific embodiment, when the thermal management system is constructed and operated in any of the above-mentioned heat exchange circuits, if the thermal management system includes a parallel battery pack branch 8, the thermal management method of the present application further comprises: The controller obtains the current battery temperature (denoted as Ti) of the battery pack 81 in each battery pack branch 8 in real time; based on the comparison result of the current battery temperature (Ti) of each battery pack branch 8 and the target temperature, and the working condition parameters, adjusts the opening degree of the control valve 82 on the battery pack branch 8, so that the heat exchange circuit communicates with the battery pack branch 8 to perform thermal management on the battery pack 81; including: If the ambient temperature is lower than the lower limit of the third preset ambient temperature range (-10℃) or the battery temperature is lower than the minimum starting temperature, the controller controls the power circuit 4 and the refrigerant circuit 3 to stop running, controls the heater 53 in the starting battery circuit 5, and controls the valve unit 7 (the six-way valve 73 and the three-way valve 72) to make the battery circuit 5 communicate with one of the second cooling liquid passage 24 or the third cooling liquid passage 25 of the multi-pass heat exchanger 1, the battery circuit 5 and the multi-pass heat exchanger 1 form a heat exchange circuit dedicated to heating in series, and the battery circuit 5 and the battery pack branch 8 are connected in parallel, the controller controls the heater 53 to heat the cooling liquid in the battery circuit 5 and the cooling liquid in the battery pack branch 8, and heats and keeps warm the battery 511 and the battery pack 81. At this time, if the current battery temperature (Ti) of a certain battery pack branch 8 exceeds the set heating target temperature, it indicates that the battery pack 81 of the branch is hot enough or overheated, the controller outputs an instruction to reduce or turn off the opening of the control valve 82 on the battery pack branch 8, thereby reducing the hot liquid flow through the battery pack branch 8 and inhibiting the further increase of the temperature thereof; if the current battery temperature (Ti) of a certain battery pack branch 8 is lower than the set heating target temperature, it indicates that the battery pack 81 of the branch is not heated enough, the controller outputs an instruction to increase the opening of the control valve 82 on the battery pack branch 8, thereby increasing the hot liquid flow through the battery pack branch 8 and accelerating the temperature rising speed thereof. If the ambient temperature is in the first ambient temperature range (5℃ to 45℃) or the second ambient temperature range (-5℃ to 5℃), the controller controls the refrigerant circuit 3 to run, and controls the valve unit 7 (the six-way valve 73 and the three-way valve 72) to make the battery circuit 5 communicate with part or all of the cooling liquid passages 22 (the first cooling liquid passage 23, the second cooling liquid passage 24, and the third cooling liquid passage 25) of the multi-pass heat exchanger 1, the battery circuit 5 and the battery pack branch 8 are connected in parallel, and the battery circuit 5 and the refrigerant circuit 3 or the power circuit 4 form a heat exchange circuit for cooling in parallel through the multi-pass heat exchanger 1 to exchange heat through the multi-pass heat exchanger 1 and cool the cooling liquid in the battery circuit 5 and the cooling liquid in the battery pack branch 8. At this time, if the current battery temperature (Ti) of a certain battery pack branch 8 exceeds the set cooling target temperature, it indicates that the battery pack 81 of the branch is not cooled enough, the controller outputs an instruction to increase the opening of the control valve 82 on the battery pack branch 8, thereby increasing the cooling liquid flow through the battery pack branch 8 and enhancing the cooling effect; if the current battery temperature (Ti) of a certain battery pack branch 8 is lower than the set cooling target temperature, it indicates that the battery pack 81 of the branch is over-cooled, the controller outputs an instruction to reduce the opening of the control valve 82 on the battery pack branch 8, thereby reducing the cooling liquid flow through the battery pack branch 8 and avoiding the temperature thereof being too low. Referring to Figure 6 In a specific embodiment, the heat management method of the present application further includes anti-condensation control of the power conversion device 411, specifically including: The controller acquires the temperature and humidity inside the chamber of the power conversion device 411 and its first heat transfer device 412. When the controller determines through an algorithm that there is a risk of condensation in the current chamber environment, it immediately sends an opening command to the throttling valve 91 on the anti-condensation throttling branch 9, controlling the throttling valve 91 to open, so that the throttling branch 9 and the power circuit 4 are connected in parallel to form a heat exchange circuit. At this time, a portion of the coolant with a higher temperature (usually above 50°C) flowing out of the outlet of the power conversion device 411 and its first heat transfer device 412 flows directly back to the inlet of the first pump 42 through the throttling branch 9, and mixes rapidly with the coolant with a lower temperature (possibly close to the ambient temperature) coming from the air-liquid heat exchanger 6, and then flows to the inlet of the power conversion device 411 and its first heat transfer device 412 to increase the temperature of the coolant flowing into the inlet of the power device 41.

[0086] This operation directly and actively increases the inlet temperature of the coolant entering the power conversion device 411 and its first heat transfer device 412 (liquid cooling plate), thereby raising the wall temperature of the first heat transfer device 412 (liquid cooling plate) itself to safely exceed the current dew point temperature of the air, thus eliminating the conditions for condensation.

[0087] This application designs a multi-channel heat exchanger 1 as a thermal hub, employing a specific configuration of alternating refrigerant channels 21 and multiple coolant channels 22 (in the order of first coolant channel 23, refrigerant channel 21, second coolant channel 24, and third coolant channel 25). Combined with controllable valve units 7 (six-way valve 73 and three-way valve 72), a dynamically reconfigurable connection topology is constructed between the refrigerant circuit 3, the liquid circuit of the power conversion device 411, and the liquid circuit of the battery 511. This enables the thermal management system to flexibly switch between multiple heat exchange circuits within a single compact platform based on real-time operating parameters through intelligent control, including forced cooling, natural cooling, internal waste heat recovery, and active heating. This achieves differentiated and precise temperature control and full-condition energy optimization for the battery 511 (low-temperature requirements) and the power conversion device 411 (relatively high-temperature requirements).

[0088] Furthermore, through the specific configuration design and controllability of the multi-channel heat exchanger 1, it fundamentally avoids harmful heat transfer between the battery circuit 5 and the power circuit 4, ensuring precise temperature control of each circuit. At the same time, the topology reconfigurability gives the system excellent environmental adaptability (wide ambient temperature) and energy efficiency, allowing it to utilize natural cold sources or recover waste heat without turning on the compressor 31. In addition, the anti-condensation function of the power conversion device 411 and the refined temperature balance control of the battery pack branch 8 together significantly improve the long-term operational reliability and safety of the system.

[0089] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A multi-channel heat exchanger, characterized in that: It includes multiple repeating flow channel units, each of which includes a refrigerant channel and multiple coolant channels, the refrigerant channel being disposed between the multiple coolant channels.

2. The multi-channel heat exchanger according to claim 1, characterized in that: Each of the flow channel units includes, in sequence: a first coolant channel, a refrigerant channel, a second coolant channel, and a third coolant channel.

3. A thermal management system, characterized in that: Includes the multi-channel heat exchanger, refrigerant circuit, power circuit, battery circuit, air-liquid heat exchanger, and valve unit as described in any one of claims 1-2; The air-liquid heat exchanger has a refrigerant side and a coolant side; The refrigerant circuit includes the refrigerant side of the air-liquid heat exchanger. The inlet and outlet of the refrigerant circuit are respectively connected to the refrigerant channel of the multi-channel heat exchanger through pipelines, and exchange heat with the battery circuit and the power circuit to cool the coolant of the battery circuit and the coolant of the power circuit. The power circuit includes a power device. The liquid inlet of the power circuit is connected to the valve unit and the coolant side outlet of the air-liquid heat exchanger via a pipeline, and its liquid outlet is connected to the coolant side inlet of the air-liquid heat exchanger via a pipeline. The power circuit can also be connected to the coolant channel of the multi-channel heat exchanger via the valve unit to exchange heat with the refrigerant circuit in order to cool the power device. The battery circuit includes a battery device. The inlet end of the battery circuit is connected to the outlet of the coolant channel of the valve unit and the multi-channel heat exchanger via a pipeline, and the outlet end is connected to the inlet of the coolant channel of the multi-channel heat exchanger via a pipeline. The battery circuit can be connected to some or all of the coolant channels to exchange heat with the refrigerant circuit in order to cool the battery device.

4. The thermal management system according to claim 3, characterized in that: The valve unit includes a valve assembly and a three-way valve; The inlet of the battery circuit is connected to the valve group via a pipeline, and is also connected to the coolant channel of the multi-channel heat exchanger via the valve group. The outlet of the battery circuit is connected to the three-way valve via a pipeline, and is also connected to the coolant channel of the multi-channel heat exchanger via the three-way valve, thus exchanging heat with the refrigerant circuit to cool the battery device. Two of the coolant channels can be connected in parallel to the battery circuit, and one of the two coolant channels can serve as a heat insulation channel between the battery circuit and the power circuit. The liquid inlet of the power circuit is connected to the valve group and the outlet of the air-liquid heat exchanger through a pipeline. The power circuit can also be connected to the coolant channel of the multi-channel heat exchanger through the valve group to exchange heat with the refrigerant circuit in order to cool the power device.

5. The thermal management system according to claim 3, characterized in that: It also includes a battery pack branch, which includes a battery pack and a control valve. The inlet and outlet of the battery pack branch are respectively connected in parallel to the inlet and outlet pipes of the battery circuit. The control valve is used to adjust the flow rate of coolant in each battery pack branch so as to make the temperature of each battery pack branch more uniform. And / or, it also includes a throttling branch, which includes a throttling valve. The inlet and outlet of the throttling branch are respectively connected to the outlet and inlet of the power device through pipelines. The throttling branch can be connected in parallel with the power circuit to exchange heat with the power circuit in order to increase the coolant temperature at the inlet of the power device.

6. A thermal management method, applied to a thermal management system as described in any one of claims 3-5, characterized in that: Includes the following steps: The operating parameters of the thermal management system are obtained, including one or more of the following: ambient temperature, power device temperature, battery device temperature, and thermal management system load. Based on the operating parameters, the working state of the valve unit is controlled so that the refrigerant circuit, the battery circuit, and the power circuit are connected in series or in parallel to form a heat exchange circuit.

7. The thermal management method according to claim 6, characterized in that: Based on the operating parameters, the operating state of the valve unit is controlled to connect the refrigerant circuit, the battery circuit, and the power circuit in series or parallel to form a heat exchange circuit, including: If the ambient temperature is within a preset first ambient temperature range, the refrigerant circuit is controlled to operate, and the valve unit is controlled to connect the battery circuit with a portion of the coolant channels of the multi-channel heat exchanger. The battery circuit and the refrigerant circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so as to exchange heat through the multi-channel heat exchanger and cool the coolant of the battery circuit. At the same time, the power circuit flows through the air-liquid heat exchanger to dissipate heat from the coolant of the power circuit. Alternatively, if the ambient temperature is within a preset first ambient temperature range and the battery device temperature exceeds a safety threshold, the refrigerant circuit is controlled to operate, and the valve unit is controlled to connect the battery circuit with all the coolant channels of the multi-channel heat exchanger. The battery circuit and the refrigerant circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so as to exchange heat through the multi-channel heat exchanger and enhance the cooling of the coolant in the battery circuit; at the same time, the power circuit flows through the air-liquid heat exchanger to dissipate heat from the coolant in the power circuit through the air-liquid heat exchanger. Alternatively, if the ambient temperature exceeds the upper limit of a preset first ambient temperature range or the power device temperature exceeds its rated upper limit, the refrigerant circuit is controlled to operate, and the valve unit is controlled to connect the battery circuit to one of the coolant channels of the multi-channel heat exchanger. The battery circuit and the refrigerant circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit for heat exchange and cooling of the coolant in the battery circuit. Simultaneously, the power circuit is connected to the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger. The coolant in the power circuit dissipates heat through the air-liquid heat exchanger. Furthermore, the power circuit and the refrigerant circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit for heat exchange and enhanced cooling of the coolant in the power circuit. During this process, thermal isolation is achieved between the battery circuit and the power circuit through the unconnected coolant channels in the multi-channel heat exchanger. Alternatively, if the ambient temperature is within a preset second ambient temperature range and the load of the thermal management system is below the load threshold, the refrigerant circuit is controlled to stop operating, and the valve unit is controlled to connect the battery circuit with part of the coolant channel of the multi-channel heat exchanger, while simultaneously connecting the power circuit with the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger. The power circuit and the battery circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit. The coolant of the power circuit dissipates heat through the air-liquid heat exchanger and exchanges heat with the battery circuit through the multi-channel heat exchanger, thereby cooling the coolant of the battery circuit. Alternatively, if the ambient temperature is within a preset third ambient temperature range, the refrigerant circuit is controlled to stop operating, the fan of the air-liquid heat exchanger is controlled to shut down, and the valve unit is controlled to connect the battery circuit with part of the coolant channel of the multi-channel heat exchanger, while simultaneously connecting the power circuit with the air-liquid heat exchanger and another coolant channel of the multi-channel heat exchanger. The power circuit and the battery circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so as to exchange heat through the multi-channel heat exchanger, and the coolant of the power circuit and the coolant of the battery circuit transfer heat to each other to cool the power device and heat and keep the battery device warm. Alternatively, if the ambient temperature is lower than the lower limit of the preset third ambient temperature range or the battery device temperature is lower than the minimum start-up temperature, the refrigerant circuit and the power circuit are controlled to stop operating, and the valve unit is controlled to connect the battery circuit with one of the coolant channels of the multi-channel heat exchanger. The battery circuit and the multi-channel heat exchanger are connected in series to form a dedicated heat exchange circuit for heating. The battery device is heated and kept warm by heating the coolant in the battery circuit.

8. The thermal management method according to claim 7, characterized in that: Also includes: Obtain the current battery temperature of the battery pack in the battery pack branch; Based on the difference between the current battery temperature and the target temperature, and the operating parameters, the opening of the control valve on the battery pack branch is adjusted to connect the heat exchange circuit to the battery pack branch, thereby performing thermal management of the battery pack; including: If the ambient temperature is lower than the lower limit of the preset third ambient temperature range or the battery device temperature is lower than the minimum start-up temperature, the power circuit and the refrigerant circuit are controlled to stop operating, and the valve unit is controlled to connect the battery circuit with one of the coolant channels of the multi-channel heat exchanger. The battery circuit and the multi-channel heat exchanger are connected in series to form a dedicated heat exchange circuit for heating, and the battery circuit and the battery pack branch are connected in parallel. The battery device and the battery pack are heated and kept warm by heating the coolant of the battery circuit and the coolant of the battery pack branch. At this time, if the current battery temperature of the battery pack branch exceeds the heating target temperature, the opening of the control valve on the battery pack branch is reduced; if the current battery temperature of the battery pack branch is lower than the heating target temperature, the opening of the corresponding control valve on the battery pack branch is increased. If the ambient temperature is within the first ambient temperature range or the second ambient temperature range, the refrigerant circuit is controlled to operate, and the valve unit is controlled to connect the battery circuit with part or all of the coolant channels of the multi-channel heat exchanger. The battery circuit and the battery pack branch are connected in parallel, and the battery circuit and the refrigerant circuit or the power circuit are connected in parallel through the multi-channel heat exchanger to form a heat exchange circuit, so as to exchange heat through the multi-channel heat exchanger and cool the coolant of the battery circuit and the coolant of the battery pack branch. At this time, if the current battery temperature of the battery pack branch exceeds the cooling target temperature, the opening of the control valve on the corresponding battery pack branch is increased; if the current battery temperature of the battery pack branch is lower than the cooling target temperature, the opening of the control valve on the corresponding battery pack branch is decreased.

9. The thermal management method according to claim 7, characterized in that: Also includes: Obtain the internal temperature and humidity parameters of the power device in the power circuit; Based on the internal temperature and humidity parameters of the power device, the throttling valve on the throttling branch is controlled to connect the power circuit and the throttling branch in parallel to form a heat exchange circuit, thereby controlling the power device to prevent condensation. If the internal temperature and humidity parameters of the power device reach the condensation risk threshold, the throttling valve is controlled so that the throttling branch and the power circuit are connected in parallel to form a heat exchange circuit. A portion of the high-temperature coolant at the outlet of the power device can flow directly to the throttling branch through the power circuit, and then flow directly to the inlet of the power circuit through the throttling branch to mix with the low-temperature coolant of the power circuit, and then flow to the inlet of the power device to increase the temperature of the coolant flowing into the inlet of the power device.

10. A photovoltaic energy storage device, characterized in that: Includes the thermal management system as described in any one of claims 3-5.

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