Vehicle and thermal management system thereof, control method, and storage medium

Abstract

A vehicle and a thermal management system thereof, a control method, and a storage medium. The system comprises a cooling oil loop, a cooling liquid loop, a refrigerant loop, a multi-way valve, and a controller; the cooling liquid loop comprises a first heat exchanger, a first three-way valve assembly, a battery, a second three-way valve assembly, and a second heat exchanger; the multi-way valve is used for selectively constructing a fluid loop, so that heat is transferred from one or more of the first heat exchanger, the cooling oil loop, and the battery to the second heat exchanger; and the controller is used for controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly so as to realize switching of multiple heat pump modes. Therefore, the switching of multiple heat pump modes can be realized by using one multi-way valve, thereby simplifying the system architecture, enriching heat pump modes, reducing the system cost, and improving the system performance.

Description

Vehicle, thermal management system, control method and storage medium thereof

[0001] Cross-references to related publications

[0002] This disclosure claims priority to Chinese patent application number 202410018920X, filed on January 3, 2024, entitled “VEHICLE AND THERMAL MANAGEMENT SYSTEM, CONTROL METHOD AND STORAGE MEDIUM THEREOF,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of vehicles, and in particular to a vehicle thermal management system, a control method for a vehicle thermal management system, a computer-readable storage medium, and a vehicle. Background Art

[0004] In order to simplify the system architecture and reduce system costs, the current electric vehicle thermal management system connects the LTR (Low Temperature heat exchanger) in series with the motor. By bypassing the LTR, a pure motor waste heat heat pump is realized. Since a certain cooling flow must be guaranteed in the motor controller to prevent the controller from overheating, it is difficult to realize the pure LTR heat pump and motor heat storage mode at the same time. Even if it can be realized, the required structure is very complex, which not only increases the hardware cost but also makes it inconvenient for subsequent maintenance.

[0005] Public content

[0006] In view of the above problems, the present disclosure provides a vehicle and its thermal management system, control method and storage medium, which can realize mode switching of multiple heat pumps by using a multi-way valve, simplifying the system architecture, enriching the heat pump mode, reducing system cost and improving system performance.

[0007] In a first aspect, the present disclosure provides a vehicle thermal management system comprising: a cooling oil circuit, a coolant circuit, a refrigerant circuit, a multi-way valve and a controller, wherein the coolant circuit comprises: a first heat exchanger, a first three-way valve assembly, a battery, a second three-way valve assembly and a second heat exchanger, and the multi-way valve is used to selectively construct a fluid circuit so that heat is transferred from one or more of the first heat exchanger, the cooling oil circuit and the battery to the second heat exchanger; the controller is configured to control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to achieve switching of multiple heat pump modes, wherein the heat pump modes include: an air source heat pump mode, a motor waste heat heat pump mode, an air source heat pump + motor waste heat heat pump mode, a motor waste heat heat pump and a battery waste heat heat pump working together mode and a battery waste heat heat pump mode.

[0008] In the technical solution of the embodiment of the present disclosure, a multi-way valve is used in conjunction with two three-way valve assemblies in the coolant circuit to switch the connectivity relationship to achieve mode switching of multiple heat pumps, thereby simplifying the system architecture, enriching the heat pump modes, reducing system costs, and improving system performance.

[0009] In some embodiments, the controller is configured to control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly based on the total system power consumption in air-source heat pump mode, the total system power consumption in motor waste heat heat pump mode, and the battery temperature to achieve switching between various heat pump modes. This allows the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch modes based on the energy consumption differences of the vehicle between different modes, maximizing the benefits of the vehicle-level thermal management system.

[0010] In some embodiments, the cooling oil circuit includes a motor, a motor controller, a motor oil pump, and an oil cooler. The refrigerant circuit includes a compressor and a third heat exchanger. The first end of the multi-way valve is connected to the first end of the first three-way valve assembly through the oil cooler. The second end of the multi-way valve is connected to the second end of the first three-way valve assembly. The third end of the first three-way valve assembly is connected to the first heat exchanger. The third end of the multi-way valve is connected to one end of the first heat exchanger. The fourth end of the multi-way valve is connected to the first end of the second three-way valve assembly through a battery. The fifth end of the multi-way valve is connected to the second end of the second three-way valve assembly. The sixth end of the multi-way valve is connected to one end of the second heat exchanger. The other end of the second heat exchanger is connected to the third end of the second three-way valve assembly. The seventh end of the multi-way valve is connected to a heater core in the passenger compartment. The eighth end of the multi-way valve is connected to the heater core through the third heat exchanger. The motor controller is disposed in the lubricating oil circuit, sharing a circuit with the oil-cooled motor, and both use the oil cooler for heat exchange with the outside world.

[0011] In some embodiments, when the heat pump mode is an air source heat pump mode, the controller is configured to control the second end of the first three-way valve assembly to be connected to the third end, and to control the second end of the multi-way valve to be connected to the fifth end, the third end to the sixth end, the seventh end and the eighth end, and to control the second end and the third end of the second three-way valve assembly to be connected.

[0012] In some embodiments, when the heat pump mode is a joint working mode of an air source heat pump and a motor waste heat heat pump, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end of the multi-way valve to be connected to the fifth end, the third end to the sixth end, the seventh end to the eighth end, and to control the second end of the second three-way valve assembly to be connected to the third end.

[0013] In some embodiments, when the heat pump mode is the motor waste heat heat pump mode, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end and the fifth end of the multi-way valve to be connected, the second end to the sixth end, the seventh end to the eighth end, and to control the second end and the third end of the second three-way valve assembly to be connected.

[0014] In some embodiments, when the heat pump mode is a joint working mode of the motor waste heat heat pump and the battery waste heat heat pump, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end of the multi-way valve to be connected to the fourth end, the second end to the sixth end, the seventh end to the eighth end, and to control the first end of the second three-way valve assembly to be connected to the third end.

[0015] In some embodiments, when the heat pump mode is the battery waste heat heat pump mode, the controller is configured to control the second end of the first three-way valve assembly to communicate with the third end, control the second end of the multi-way valve to communicate with the third end, the fourth end to communicate with the sixth end, and the seventh end to communicate with the eighth end, and control the first end of the second three-way valve assembly to communicate with the third end. This allows the communication relationship between the first three-way valve assembly, the second three-way valve assembly, and the multi-way valve to be changed according to the heat pump mode to switch to the corresponding heat pump mode.

[0016] In some embodiments, the controller is configured to, when the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the air source heat pump mode; when the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the motor waste heat heat pump mode. When the air source heat is sufficient and the electric drive heat is relatively small, the motor oil pump only meets the lubrication requirements. At this time, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the air source heat pump mode, serving as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0017] In some embodiments, when switching to the air source heat pump mode, the controller is further configured to obtain a first amount of heat obtained by the compressor from the environment and a second amount of heat dissipated by the motor to the environment; when the first amount of heat is greater than or equal to the second amount of heat, the air source heat pump mode is maintained unchanged; when the first amount of heat is less than the second amount of heat, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to a mode in which the air source heat pump and the motor waste heat heat pump work together. When the amount of heat obtained from the environment is less than the amount of heat dissipated by the motor to the environment, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to a mode in which the air source heat pump and the motor waste heat heat pump work together, acting as a low-temperature heat source for the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0018] In some embodiments, when switching to a mode in which the air source heat pump and the motor waste heat heat pump operate together, the controller is further configured to obtain the water inlet temperature and ambient temperature of the first heat exchanger; when the water inlet temperature is less than or equal to the ambient temperature, maintain the air source heat pump and the motor waste heat heat pump in the combined operating mode; and when the water inlet temperature is greater than the ambient temperature, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the motor waste heat heat pump mode. When the motor heat is sufficient, the motor acts as a low-temperature heat source, fully mobilizing the motor heat to participate in the vehicle thermal management system, maximizing the utilization of the motor waste heat and maximizing the benefits of the vehicle-level thermal management system.

[0019] In some embodiments, when switching to the motor waste heat heat pump mode, the controller is further configured to obtain the battery temperature; if the battery temperature is lower than the motor oil temperature, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to a mode in which the motor waste heat heat pump and the battery waste heat pump operate together; and if the battery temperature is higher than a preset temperature threshold, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the battery waste heat heat pump mode. This allows for comprehensive consideration of the energy consumption differences of the vehicle between different modes, more accurately achieving switching between modes and maximizing the benefits of the thermal management system.

[0020] In some embodiments, the controller is further configured to obtain the passenger compartment heating demand and system efficiency; obtain the driving power and motor efficiency required to maintain the target vehicle speed; determine the total system power consumption in air source heat pump mode and the total system power consumption in motor waste heat heat pump mode based on the ratio of the passenger compartment heating demand to the system efficiency and the sum of the ratios of the driving power and the motor efficiency; wherein the system efficiency in air source heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency are different from the system efficiency in motor waste heat heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency.

[0021] In some embodiments, the controller is further configured to control the motor oil pump to operate at a preset speed when switched to air-source heat pump mode; and to determine the motor oil pump speed based on the target air outlet temperature of the heater core when switched to one of the following modes: motor waste heat heat pump mode, air-source heat pump and motor waste heat heat pump combined mode, or motor waste heat heat pump and battery waste heat heat pump combined mode. This allows the motor oil pump speed to be actively controlled based on heat demand, removing more heat from the motor and maximizing the utilization of the motor's waste heat.

[0022] In a second aspect, the present disclosure provides a control method for a vehicle thermal management system, the method comprising: obtaining the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat heat pump mode, and the temperature of a battery; controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly according to the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat heat pump mode, and the temperature of the battery to achieve switching of multiple heat pump modes, wherein the heat pump modes comprise: air source heat pump mode, motor waste heat heat pump mode, air source heat pump and motor waste heat heat pump working together mode, motor waste heat heat pump and battery waste heat heat pump working together mode, and battery waste heat heat pump mode.

[0023] In the technical solution of the embodiment of the present disclosure, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled according to the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode and the temperature of the battery to realize the switching of multiple heat pump modes, and comprehensively consider the energy consumption differences of the whole vehicle between different modes. For example, the difference in resistance of the whole vehicle caused by the front-end fan being turned on when the air source heat pump is used and the front-end fan being turned off when the waste heat heat pump (battery waste heat heat pump or motor waste heat heat pump) is used, so as to realize the switching between the various modes more accurately and maximize the benefits of the thermal management system at the vehicle level.

[0024] In some embodiments, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch between multiple heat pump modes, including: when the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the air source heat pump mode; when the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the motor waste heat heat pump mode. When the air source heat is sufficient and the electric drive heat is relatively small, the motor oil pump only meets the lubrication requirement. At this time, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the air source heat pump mode, serving as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0025] In some embodiments, when switching to the air source heat pump mode, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to achieve switching between multiple heat pump modes, including: obtaining a first heat obtained by the compressor from the environment and a second heat dissipated by the motor to the environment; when the first heat is greater than or equal to the second heat, the air source heat pump mode is maintained unchanged; when the first heat is less than the second heat, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to a mode in which the air source heat pump and the motor waste heat heat pump work together. When the heat obtained from the environment is less than the heat dissipated by the motor to the environment, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to a mode in which the air source heat pump and the motor waste heat heat pump work together, serving as a low-temperature heat source for the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0026] In some embodiments, when switching to a mode in which the air source heat pump and the motor waste heat heat pump operate together, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch between multiple heat pump modes, including: obtaining the water inlet temperature and the ambient temperature of the first heat exchanger; when the water inlet temperature is less than or equal to the ambient temperature, maintaining the air source heat pump and the motor waste heat heat pump in the mode in which the air source heat pump and the motor waste heat heat pump operate together; when the water inlet temperature is greater than the ambient temperature, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the motor waste heat heat pump mode. The motor heat is sufficient, and at this time, the motor acts as a low-temperature heat source, fully mobilizing the motor heat to participate in the vehicle thermal management system, maximizing the utilization of the motor waste heat, and maximizing the benefits of the vehicle-level thermal management system.

[0027] In some embodiments, when switching to the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to achieve switching between multiple heat pump modes, including: obtaining the battery temperature; if the battery temperature is lower than the motor oil temperature, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the motor waste heat heat pump + battery waste heat heat pump mode; if the battery temperature is higher than a preset temperature threshold, the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to switch to the battery waste heat heat pump mode. This allows for comprehensive consideration of the energy consumption differences of the vehicle between different modes, more accurately achieving switching between modes, and maximizing the benefits of the thermal management system.

[0028] In some embodiments, the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat heat pump mode and the temperature of the battery are obtained, including: obtaining the passenger compartment heating demand and system efficiency; obtaining the driving power and motor efficiency required to maintain the target vehicle speed; determining the total system power consumption in air source heat pump mode and the total system power consumption in motor waste heat heat pump mode based on the ratio of the passenger compartment heating demand to the system efficiency and the sum of the ratios of the driving power and the motor efficiency; wherein, the system efficiency in air source heat pump mode, the driving power and motor efficiency required to maintain the target vehicle speed and the system efficiency in motor waste heat heat pump mode are different from the system efficiency in motor waste heat heat pump mode, the driving power and motor efficiency required to maintain the target vehicle speed.

[0029] In some embodiments, the control method further includes: controlling the motor oil pump to operate at a preset speed when switching to air source heat pump mode; and determining the motor oil pump speed based on the target air outlet temperature of the heater core when switching to one of the following modes: motor waste heat heat pump mode, air source heat pump and motor waste heat heat pump combined mode, or motor waste heat heat pump and battery waste heat heat pump combined mode. This allows the motor oil pump speed to be actively controlled based on heat demand, removing more heat from the motor and maximizing motor waste heat utilization.

[0030] In a third aspect, the present disclosure provides a computer-readable storage medium storing a control program for a vehicle thermal management system. When the control program for the vehicle thermal management system is executed by a processor, the control method for the vehicle thermal management system in the above embodiment is implemented.

[0031] In a fourth aspect, the present disclosure provides a vehicle comprising the above-mentioned vehicle thermal management system.

[0032] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical aspects of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present disclosure. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0034] FIG1 is a schematic structural diagram of a vehicle thermal management system according to some embodiments of the present disclosure;

[0035] FIG2 is a schematic structural diagram of a vehicle thermal management system according to some embodiments of the present disclosure;

[0036] FIG3 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0037] FIG4 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0038] FIG5 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0039] FIG6 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0040] FIG7 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0041] FIG8 is a flow chart of a control method of a vehicle thermal management system according to some embodiments of the present disclosure;

[0042] FIG9 is a flow chart of a control method of a vehicle thermal management system according to some embodiments of the present disclosure;

[0043] FIG10 is a block diagram of a vehicle according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0044] The following embodiments of the technical solution of the present disclosure are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present disclosure and are therefore only examples and are not intended to limit the scope of protection of the present disclosure.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the terms "including" and "having" and any variations thereof in the specification and claims of the present disclosure and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0046] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0047] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] In the description of the embodiments of the present disclosure, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0049] In the description of the embodiments of the present disclosure, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0050] In the description of the embodiments of the present disclosure, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0051] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and they can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0052] In order to simplify the system architecture and reduce system costs, the current electric vehicle thermal management system connects the LTR (Low Temperature heat exchanger) in series with the motor. By bypassing the LTR, a pure motor waste heat heat pump is realized. Since a certain cooling flow must be guaranteed in the motor controller to prevent the controller from overheating, it is difficult to realize the pure LTR heat pump and motor heat storage mode at the same time. Even if it can be realized, the required structure is very complex, which not only increases the hardware cost but also makes it inconvenient for subsequent maintenance.

[0053] Secondly, current thermal management systems can generally choose between multiple heat sources, and there are many corresponding heat pump modes, including pure LTR heat pump, motor waste heat electric pump, LTR + motor waste heat heat pump. How to optimize the control algorithm and more accurately switch between modes from the perspective of vehicle energy benefits to maximize the benefits of the thermal management system has become an industry problem.

[0054] To this end, the present invention constructs a thermal management system architecture based on water circuits. The motor controller, onboard charger, and other controller components adopt an oil-cooling solution. In terms of architecture, they share a circuit with the oil-cooled motor, and use the oil cooler to exchange heat with the outside world. Using only an eight-way valve, multiple heat pump modes are implemented, including a pure LTR heat pump, a motor waste heat heat pump, a LTR and motor waste heat heat pump working together, a motor waste heat pump and a battery waste heat pump working together, and a battery waste heat heat pump. While simplifying the system architecture, a rich variety of heat pump modes are still implemented, achieving a perfect combination of low cost and high performance.

[0055] For the convenience of description, the following embodiments are described by taking a vehicle thermal management system according to some embodiments of the present disclosure as an example.

[0056] Please refer to Figure 1. The present disclosure provides a vehicle thermal management system, which may include: a cooling oil circuit (shown by a dotted line in the figure), a coolant circuit (shown by a solid line in the figure), a refrigerant circuit (shown by a dotted line in the figure), a multi-way valve 40 and a controller (not specifically shown in the figure), wherein the cooling oil circuit includes a motor 11, a motor controller 12, a motor oil pump 13 and an oil cooler 14, the coolant circuit includes: a first heat exchanger 21, a first three-way valve assembly 22, a battery 23, a second three-way valve assembly 24 and a second heat exchanger 25, the refrigerant circuit includes a compressor 31 and a third heat exchanger 32, a first end of the multi-way valve 40 is connected to a first end of the first three-way valve assembly 22 through the oil cooler 14, a second end of the multi-way valve 40 is connected to a second end of the first three-way valve assembly 22, a third end of the first three-way valve assembly 22 is connected to the first heat exchanger 21, and a third end of the multi-way valve 40 is connected to the first heat exchanger 21. The controller is configured to control the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 to realize switching of multiple heat pump modes, wherein the heat pump modes include: air source heat pump mode, motor waste heat heat pump mode, air source heat pump and motor waste heat heat pump working together mode, motor waste heat heat pump and battery waste heat heat pump working together mode and battery waste heat heat pump mode.

[0057] In the technical solution of the embodiment of the present disclosure, for the cooling oil circuit, one end of the motor 11 is connected to one end of the motor controller 12, the other end of the motor controller 12 is connected to the first end of the oil cooler 14, the second end of the oil cooler 14 is connected to one end of the motor oil pump 13, and the other end of the motor oil pump 13 is connected to the other end of the motor 11. For the coolant circuit, one end of the first heat exchanger 21 is connected to the third end of the first three-way valve assembly 22, the first end of the first three-way valve assembly 22 is connected to the third end of the oil cooler 14, and the fourth end of the oil cooler 14 is connected to the first end of the multi-way valve 40. The second end of the first three-way valve assembly 22 is connected to the second end of the multi-way valve 40, and the other end of the first heat exchanger 21 is connected to the third end of the multi-way valve 40 through a water pump; one end of the battery 23 is connected to the fourth end of the multi-way valve 40, and the other end of the battery 23 is connected to the first end of the second three-way valve assembly 24, the second end of the second three-way valve assembly 24 is connected to the fifth end of the multi-way valve 40, the third end of the second three-way valve assembly 24 is connected to the first end of the second heat exchanger 25, the second end of the second heat exchanger 25 is connected to the sixth end of the multi-way valve 40 through a water pump, the seventh end of the multi-way valve 40 is connected to the heater core, and the eighth end of the multi-way valve 40 is connected to the heater core through the third heat exchanger 32 and the water pump in the refrigerant circuit. For the refrigerant circuit, the output port of the compressor 31 in the refrigerant circuit is connected to the first end of the third heat exchanger 32, the second end of the third heat exchanger 32 is connected to the third end of the second heat exchanger 25 through a throttling element, and the fourth end of the second heat exchanger 25 is connected to the return air port of the compressor.

[0058] The lubricating oil in the lubricating oil circuit exchanges heat with the coolant in the coolant circuit via the oil cooler 14. The coolant in the coolant circuit exchanges heat with the refrigerant in the refrigerant circuit via the second heat exchanger 25. The refrigerant in the refrigerant circuit exchanges heat with the passenger compartment's heater core via the third heat exchanger 32, thereby meeting the passenger compartment's needs through the heater core. The heat pump mode is switched by adjusting the connectivity of the multi-way valve 40, the connectivity direction of the first three-way valve assembly 22, and the connectivity of the second three-way valve assembly 24. Thus, by placing the motor controller in the lubricating oil circuit, sharing the circuit with the oil-cooled motor and using the oil cooler together for heat exchange with the outside world, and using a single multi-way valve in conjunction with the two three-way valve assemblies in the coolant circuit to switch connectivity, multiple heat pump modes can be achieved. This simplifies the system architecture, enriches the heat pump modes, reduces system costs, and improves system performance.

[0059] In some embodiments, the multi-way valve 40 may be an eight-way valve.

[0060] In some embodiments, the controller is configured to control the multi-way valve 40, the first three-way valve assembly 22, and the second three-way valve assembly 24 based on the total system power consumption in the air-source heat pump mode, the total system power consumption in the motor waste heat heat pump mode, and the battery temperature to achieve switching between various heat pump modes. This allows the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch modes based on the energy consumption differences of the vehicle between different modes, maximizing the benefits of the vehicle-level thermal management system.

[0061] In some embodiments, as shown in FIG2 , the coolant circuit may further include a PTC (Positive Temperature Coefficient) heater 29. One end of the PTC heater 29 is connected to the fourth end of the oil cooler 14, and the other end of the PTC heater 29 is connected to the first end of the multi-way valve 40. Because the motor 11 has a low-efficiency operation and stall heating function, the PTC heater can be eliminated, reducing system costs.

[0062] To facilitate the demonstration of various mode switching, in the following embodiments, the lubricating oil circuit, refrigerant circuit, and coolant circuit are represented by solid lines, while dashed lines indicate disconnected portions. Furthermore, while the following description uses a PTC heater as an example, it should be noted that the heat pump mode switching described below can also be achieved without the PTC heater.

[0063] In some embodiments, when the heat pump mode is an air source heat pump mode, the controller is configured to control the second end of the first three-way valve assembly 22 to be connected to the third end, and to control the second end of the multi-way valve 40 to be connected to the fifth end, the third end to the sixth end, the seventh end and the eighth end, and to control the second end and the third end of the second three-way valve assembly 24 to be connected.

[0064] Specifically, as shown in Figure 3, the first heat exchanger 21, the first three-way valve assembly 22, the multi-way valve 40, the second three-way valve assembly 24, the second heat exchanger 25, the first water pump 26, and the second water pump 27 are connected to serve as the low-temperature heat source of the heat pump (air source heat pump mode). The connection direction of the air source heat pump mode is the first heat exchanger 21 → the first three-way valve assembly 22 (the third end and the second end are connected) → the multi-way valve (the second end and the fifth end are connected) → the second three-way valve assembly 24 (the second end and the third end are connected) → the second heat exchanger 25 → the first water pump 26 → the multi-way valve 40 (the sixth end and the third end are connected) → the second water pump 27 → the first heat exchanger 21; the third heat exchanger 32 → the third water pump 28 → the heater core 50 → the multi-way valve (the seventh end and the eighth end are connected) → the third heat exchanger 32; the motor 11, the motor controller 12, the oil cooler 14, and the motor oil pump 13 form a lubricating oil circuit. The coolant circuit exchanges heat with the refrigerant circuit through the second heat exchanger 25 , and the refrigerant circuit then exchanges heat with the heater core through the third heat exchanger 32 , transferring heat to the passenger compartment through the heater core.

[0065] In some embodiments of the present disclosure, the first heat exchanger 21 may be a low-temperature heat exchanger, the second heat exchanger may be a plate heat exchanger, and the third heat exchanger may be a water-cooled heat exchanger.

[0066] In some embodiments, when the heat pump mode is a joint working mode of an air source heat pump and a motor waste heat heat pump, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end of the multi-way valve to be connected to the fifth end, the third end to the sixth end, the seventh end to the eighth end, and to control the second end of the second three-way valve assembly to be connected to the third end.

[0067] Specifically, as shown in Figure 4, the first heat exchanger 21, the first three-way valve assembly 22, the oil cooler 14, the PTC heater 29, the multi-way valve 40, the second three-way valve assembly 24, the second heat exchanger 25, the first water pump 26 and the second water pump 27 are connected as the low-temperature heat source of the heat pump (the air source heat pump and the motor waste heat heat pump mode work together). The connection direction of the air source heat pump and the motor waste heat heat pump in the joint working mode is the first heat exchanger 21 → the first three-way valve assembly 22 (the third end and the first end are connected) → the oil cooler 14 → the PTC heater 29 → the multi-way valve 40 (the first end and the fifth end are connected) → the second three-way valve assembly 24 (the second end and the third end are connected) → the second heat exchanger 25 → the first water pump 26 → the multi-way valve 40 (the sixth end and the third end are connected) → the second water pump 27 → the first heat exchanger 21; the motor 11 → the motor controller 12 → the oil cooler 14 → the motor oil pump 13 → the motor 11; the third heat exchanger 32 → the third water pump 28 → the warm air core 50 → the multi-way valve 40 (the seventh end and the eighth end are connected) → the third heat exchanger 32. The lubricating oil circuit exchanges heat with the coolant circuit through the oil cooler 14, the coolant circuit exchanges heat with the refrigerant circuit through the second heat exchanger 25, and the refrigerant circuit exchanges heat with the heater core through the third heat exchanger 32, and the heat is transferred to the passenger compartment through the heater core.

[0068] In some embodiments, when the heat pump mode is the motor waste heat heat pump mode, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end and the fifth end of the multi-way valve to be connected, the second end to the sixth end, the seventh end to the eighth end, and to control the second end and the third end of the second three-way valve assembly to be connected.

[0069] Specifically, as shown in FIG5 , the first three-way valve assembly 22, the oil cooler 14, the PTC heater 29, the multi-way valve 40, the second three-way valve assembly 24, the second heat exchanger 25, and the first water pump 26 are connected to serve as the low-temperature heat source of the heat pump (motor waste heat heat pump mode). The connection direction in the motor waste heat heat pump mode is oil cooler 14 → PTC heater 29 → multi-way valve 40 (first and fifth ends connected) → second three-way valve assembly 24 (second and third ends connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth and second ends connected) → first three-way valve assembly 22 (second and first ends connected) → oil cooler 14; motor 11 → motor controller 12 → oil cooler 14 → motor oil pump 13 → motor 11; third heat exchanger 32 → third water pump 28 → heater core 50 → multi-way valve 40 (seventh and eighth ends connected) → third heat exchanger 32. The lubricating oil circuit exchanges heat with the coolant circuit through the oil cooler 14, the coolant circuit exchanges heat with the refrigerant circuit through the second heat exchanger 25, and the refrigerant circuit exchanges heat with the heater core through the third heat exchanger 32, and the heat is transferred to the passenger compartment through the heater core.

[0070] In some embodiments, when the heat pump mode is a joint working mode of the motor waste heat heat pump and the battery waste heat heat pump, the controller is configured to control the first end of the first three-way valve assembly to be connected to the second end, and to control the first end of the multi-way valve to be connected to the fourth end, the second end to the sixth end, the seventh end to the eighth end, and to control the first end of the second three-way valve assembly to be connected to the third end.

[0071] Specifically, as shown in Figure 6, the oil cooler 14, the PTC heater 29, the multi-way valve 40, the battery 23, the second three-way valve assembly 24, the second heat exchanger 25, the first water pump 26, and the first three-way valve assembly 22 are connected as a low-temperature heat source for the heat pump (the motor waste heat heat pump and the battery waste heat heat pump work in a joint mode). The connection direction of the motor waste heat heat pump and the battery waste heat heat pump in the joint working mode is oil cooler 14 → PTC heater 29 → multi-way valve 40 (the first end and the fourth end are connected) → battery 23 → second three-way valve assembly 24 (the first end and the third end are connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (the sixth end and the second end are connected) → first three-way valve assembly 22 (the second end and the first end are connected) → oil cooler 14; motor 11 → motor controller 12 → oil cooler 14 → motor oil pump 13 → motor 11; third heat exchanger 32 → third water pump 28 → warm air core 50 → multi-way valve 40 (the seventh end and the eighth end are connected) → third heat exchanger 32. The lubricating oil circuit exchanges heat with the coolant circuit through the oil cooler 14, the coolant circuit exchanges heat with the refrigerant circuit through the second heat exchanger 25, and the refrigerant circuit exchanges heat with the heater core through the third heat exchanger 32, and the heat is transferred to the passenger compartment through the heater core.

[0072] In some embodiments, when the heat pump mode is the battery waste heat heat pump mode, the controller is configured to control the second end of the first three-way valve assembly to communicate with the third end, control the second end of the multi-way valve to communicate with the third end, the fourth end to communicate with the sixth end, and the seventh end to communicate with the eighth end, and control the first end of the second three-way valve assembly to communicate with the third end. This allows the communication relationship between the first three-way valve assembly, the second three-way valve assembly, and the multi-way valve to be changed according to the heat pump mode to switch to the corresponding heat pump mode.

[0073] Specifically, as shown in Figure 7, the multi-way valve 40, battery 23, second three-way valve assembly 24, second heat exchanger 25, and first water pump 26 are connected to serve as the low-temperature heat source of the heat pump (battery waste heat heat pump mode). The connection direction in the battery waste heat heat pump mode is battery 23 → second three-way valve assembly 24 (first and third ends connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth and fourth ends connected) → battery 23; third heat exchanger 32 → third water pump 28 → heater core 50 → multi-way valve 40 (seventh and eighth ends connected) → third heat exchanger 32; first heat exchanger 21 → first three-way valve assembly 22 (third and second ends connected) → multi-way valve 40 (second and third ends connected) → second water pump 27 → first heat exchanger 21; motor 11 → motor controller 12 → oil cooler 14 → motor oil pump 13 → motor 11. The coolant circuit exchanges heat with the refrigerant circuit through the second heat exchanger 25 , and the refrigerant circuit then exchanges heat with the heater core 50 through the third heat exchanger 32 , and transfers heat to the passenger compartment through the heater core 50 .

[0074] In some embodiments, the controller is configured to control the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 to switch to the air source heat pump mode when the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode; and to control the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 to switch to the motor waste heat heat pump mode when the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode.

[0075] In some embodiments, the controller is further configured to obtain the passenger compartment heating demand and system efficiency; obtain the driving power and motor efficiency required to maintain the target vehicle speed; determine the total system power consumption in air source heat pump mode and the total system power consumption in motor waste heat heat pump mode based on the ratio of the passenger compartment heating demand to the system efficiency and the sum of the ratios of the driving power and the motor efficiency; wherein the system efficiency in air source heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency are different from the system efficiency in motor waste heat heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency.

[0076] Specifically, the passenger compartment heating demand Q0 is first obtained, where Q0 = air density ρ * air volume of the air conditioner * (air conditioner outlet enthalpy value - air inlet enthalpy value). The target outlet temperature can be calculated by the air conditioner heat load algorithm; the driving power can be calculated based on the vehicle speed and the drag coefficient of the vehicle body, as well as the slope and AGS (Active Grille System) opening correction.

[0077] According to the principle of conservation of energy, Calculate the driving power P1 required to maintain the target vehicle speed in the air source heat pump mode. The motor oil temperature after the motor's own heat storage stabilizes is T1. The corresponding motor efficiency at this time is η1. The heat pump absorbs heat from the environment, and the system efficiency (heat pump system efficiency) is ε1. From this, the total system power consumption in the air source heat pump mode can be obtained. The first heat that the compressor takes from the environment The second heat Q dissipated by the motor to the environment p1 =A·k·(T1-T0). Where T0 is the ambient temperature, A is the motor's heat dissipation surface area, and k is the convection heat transfer coefficient with the air.

[0078] According to the principle of conservation of energy, Calculate the driving power P2 required to maintain the target vehicle speed in the motor waste heat heat pump mode (because the front fan (the front fan is the fan corresponding to the first heat exchanger) is turned off, the resistance is reduced, so P2 < P1). The motor oil temperature after the motor's own heat storage is stable is T2. The corresponding motor efficiency at this time is η2. The heat pump absorbs heat from the motor, and the system efficiency is ε2. From this, the total system power consumption in the motor waste heat heat pump mode can be obtained. Alternatively, the system efficiency, ε (including ε1 and ε2), can be calculated by determining the steady-state air volume in the passenger compartment based on the target set temperature and ambient temperature, and then looking up the system efficiency at that steady-state air volume from a table. Alternatively, the system efficiency, ε (including ε1 and ε2), can be calculated by looking up the system efficiency from a table based on the refrigerant flow rate and the high and low pressure ratio of the compressor.

[0079] The convective heat transfer coefficient k between the motor and the air can be obtained by looking up a table at different ambient temperatures and vehicle speeds. The motor efficiency η can be obtained by looking up a table based on the motor oil temperature and motor power.

[0080] Therefore, when the air source heat is sufficient and the electric drive heat is relatively small, the motor oil pump only meets the lubrication requirements. At this time, the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 are controlled to switch to the air source heat pump mode, which serves as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0081] In some embodiments, when switching to the air source heat pump mode, the controller is also configured to obtain the first heat obtained by the compressor 31 from the environment and the second heat dissipated by the motor 11 to the environment; when the first heat is greater than or equal to the second heat, the air source heat pump mode is maintained unchanged; when the first heat is less than the second heat, the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 are controlled to switch to the joint working mode of the air source heat pump and the motor waste heat heat pump.

[0082] According to the above embodiment, when the heat obtained from the environment is less than the heat dissipated by the motor to the environment, the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 are controlled to switch to the air source heat pump + motor waste heat heat pump mode, which serves as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0083] In some embodiments, when switching to the air source heat pump + motor waste heat heat pump mode, the controller is also configured to obtain the water inlet temperature and ambient temperature of the first heat exchanger 21; when the water inlet temperature is less than or equal to the ambient temperature, the air source heat pump and the motor waste heat heat pump work in a common mode unchanged; when the water inlet temperature is greater than the ambient temperature, the multi-way valve 40, the first three-way valve assembly 22 and the second three-way valve assembly 24 are controlled to switch to the motor waste heat heat pump mode.

[0084] In other words, the motor has sufficient heat. At this time, the motor acts as a low-temperature heat source, fully mobilizing the motor heat to participate in the vehicle's thermal management system, maximizing the utilization of the motor's waste heat, and maximizing the benefits of the vehicle-level thermal management system.

[0085] In some embodiments, when switching to the motor waste heat heat pump mode, the controller is further configured to obtain the temperature of the battery 23; if the temperature of the battery 23 is lower than the oil temperature of the motor 11, the controller controls the multi-way valve 40, the first three-way valve assembly 22, and the second three-way valve assembly 24 to switch to a mode in which the motor waste heat heat pump and the battery waste heat pump operate together; and if the temperature of the battery 23 is higher than a preset temperature threshold, the controller controls the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the battery waste heat pump mode. The preset temperature threshold can be calibrated based on actual conditions.

[0086] That is, when the battery temperature is lower than the oil temperature of motor 11, the excess heat is used to heat the battery, with the battery and motor waste heat acting as low-temperature heat sources, switching to a combined motor and battery waste heat heat pump mode. When the battery temperature rises above a preset threshold, indicating sufficient battery heat, the waste heat from battery 23 serves as the low-temperature heat source, switching to battery waste heat heat pump mode. This allows for comprehensive consideration of vehicle energy consumption differences between different modes, enabling more precise switching between modes and maximizing the effectiveness of the thermal management system.

[0087] In some embodiments, the controller is further configured to, when switched to air-source heat pump mode, control the motor oil pump to operate at a preset speed; and, when switched to one of the motor waste heat heat pump mode, the air-source heat pump and motor waste heat heat pump combined mode, or the motor waste heat heat pump and battery waste heat heat pump combined mode, determine the motor oil pump speed based on the target outlet air temperature of the heater core. The preset speed can be calibrated based on actual conditions; for example, the preset speed can be set to meet the minimum speed for the motor lubricating oil.

[0088] Specifically, in air-source heat pump mode, the motor oil pump 13 only meets lubrication requirements, so its speed is relatively low. In motor waste heat heat pump mode, in combined operation of an air-source heat pump and motor waste heat pump, or in combined operation of a motor waste heat pump and battery waste heat pump, the motor acts as a low-temperature heat source, and the motor oil pump speed needs to be coordinated and controlled based on the heating capacity to control the amount of heat the motor can provide to the heat pump system. For example, the motor oil pump speed can be obtained by querying the corresponding table based on the target air outlet temperature of the heater core, as shown in Table 1.

[0089] Table 1

[0090] Table 1 shows that when the target air outlet temperature is 30°C, the corresponding motor oil pump speed is 2000 rad / s; when the target air outlet temperature is 50°C, the corresponding motor oil pump speed is 4000 rad / s. This allows the motor oil pump speed to be actively controlled based on heat demand, removing more heat from the motor and maximizing waste heat utilization.

[0091] It should be noted that, in order to meet the minimum speed of the motor lubricating oil, the larger of the minimum speed of the motor lubricating oil and the speed of the motor oil pump is used as the final speed of the motor oil pump.

[0092] As a specific example, as shown in FIG8 , the control method of the vehicle thermal management system may include the following steps:

[0093] S101, obtain the passenger compartment heating demand and target vehicle speed, and execute steps S102 and S104 respectively.

[0094] S102 , obtaining the system efficiency, motor efficiency, and power required to maintain the target vehicle speed in the air source heat pump mode.

[0095] S103 , calculating the total system power consumption W1 in the air heat pump mode, and executing S106 .

[0096] S104 , obtaining the system efficiency, motor efficiency, and power required to maintain the target vehicle speed in the motor waste heat heat pump mode.

[0097] S105 , calculating the total power consumption W2 of the system in the motor waste heat heat pump mode.

[0098] S106, determine whether W1 < W2. If yes, go to step S107; if not, go to step S113.

[0099] S107, switch to air source heat pump mode.

[0100] S108 , obtaining a first heat Qc1 obtained by the compressor from the environment and a second heat Qp1 dissipated by the motor to the environment in the air source heat pump mode.

[0101] S109, determine whether Qc1 < Qp1 holds. If so, proceed to step S110; if not, return to step S107.

[0102] S110, switching to a joint working mode of the air source heat pump and the motor waste heat heat pump.

[0103] S111, obtaining the water inlet temperature of the first heat exchanger.

[0104] S112: Determine whether the inlet water temperature is greater than the ambient temperature. If yes, proceed to step S113; if not, return to step S110.

[0105] S113, switching to the motor waste heat heat pump mode.

[0106] S114: Obtain the battery temperature.

[0107] S115: Determine whether the battery temperature is lower than the motor oil temperature. If so, proceed to step S116; if not, proceed to step S117.

[0108] S116, switching to a joint working mode of the motor waste heat heat pump and the battery waste heat heat pump.

[0109] S117: Determine whether the battery temperature is greater than a preset temperature. If yes, proceed to step S118; if no, return to step S116.

[0110] S118, switching to battery waste heat heat pump mode.

[0111] In summary, in the technical solution of the embodiment of the present disclosure, a multi-way valve is used in conjunction with two three-way valve assemblies in the coolant circuit to switch the connectivity relationship to achieve mode switching of multiple heat pumps, which simplifies the system architecture, enriches the heat pump modes, reduces system costs, and improves system performance.

[0112] In a second aspect, the present disclosure provides a control method for a vehicle thermal management system.

[0113] As shown in FIG9 , the control method of the vehicle thermal management system according to the embodiment of the present disclosure includes the following steps:

[0114] S1, obtaining the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat heat pump mode, and the battery temperature.

[0115] S2, controls the multi-way valve, the first three-way valve assembly and the second three-way valve assembly according to the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode and the temperature of the battery to realize switching of multiple heat pump modes, wherein the heat pump modes include: air source heat pump mode, motor waste heat heat pump mode, air source heat pump and motor waste heat heat pump working together mode, motor waste heat heat pump and battery waste heat heat pump working together mode and battery waste heat heat pump mode.

[0116] In the technical solution of the embodiment of the present disclosure, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled according to the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode and the temperature of the battery to realize the switching of multiple heat pump modes, and comprehensively consider the energy consumption differences of the whole vehicle between different modes. For example, the difference in resistance of the whole vehicle caused by the front-end fan being turned on when the air source heat pump is used and the front-end fan being turned off when the waste heat heat pump (motor waste heat heat pump or battery waste heat heat pump) is used, so as to realize the switching between the various modes more accurately and maximize the benefits of the thermal management system at the vehicle level.

[0117] In some embodiments, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to achieve switching of multiple heat pump modes, including: when the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the air source heat pump mode; when the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the motor waste heat heat pump mode.

[0118] In some embodiments, the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat heat pump mode and the temperature of the battery are obtained, including: obtaining the passenger compartment heating demand and system efficiency; obtaining the driving power and motor efficiency required to maintain the target vehicle speed; determining the total system power consumption in air source heat pump mode and the total system power consumption in motor waste heat heat pump mode based on the ratio of the passenger compartment heating demand to the system efficiency and the sum of the ratios of the driving power and the motor efficiency; wherein, the system efficiency in air source heat pump mode, the driving power and motor efficiency required to maintain the target vehicle speed and the system efficiency in motor waste heat heat pump mode are different from the system efficiency in motor waste heat heat pump mode, the driving power and motor efficiency required to maintain the target vehicle speed.

[0119] Specifically, the passenger compartment heating demand Q0 is first obtained, where Q0 = air density ρ * air volume of the air conditioner * (air conditioner outlet enthalpy value - air inlet enthalpy value). The target outlet temperature can be calculated by the air conditioner heat load algorithm; the driving power can be calculated based on the vehicle speed and the drag coefficient of the vehicle body, as well as the slope and AGS (Active Grille System) opening correction.

[0120] According to the principle of conservation of energy, Calculate the driving power P1 required to maintain the target vehicle speed in air source heat pump mode. The motor oil temperature after the motor's own heat storage stabilizes is T1. The corresponding motor efficiency is η1. The heat pump absorbs heat from the environment, and the system efficiency is ε1. From this, the total system power consumption in air source heat pump mode can be obtained. The first heat that the compressor takes from the environment The second heat Q dissipated by the motor to the environment p1 =A·k·(T1-T0). Where T0 is the ambient temperature, A is the motor's heat dissipation surface area, and k is the convection heat transfer coefficient with the air.

[0121] According to the principle of conservation of energy, Calculate the driving power P2 required to maintain the target vehicle speed in the motor waste heat heat pump mode (because the front fan (the front fan is the fan corresponding to the first heat exchanger) is turned off, the resistance is reduced, so P2 < P1). The motor oil temperature after the motor's own heat storage is stable is T2. The corresponding motor efficiency at this time is η2. The heat pump absorbs heat from the motor, and the system efficiency is ε2. From this, the total system power consumption in the motor waste heat heat pump mode can be obtained. Alternatively, the system efficiency, ε (including ε1 and ε2), can be calculated by determining the steady-state air volume in the passenger compartment based on the target set temperature and ambient temperature, and then looking up the system efficiency at that steady-state air volume from a table. Alternatively, the system efficiency, ε (including ε1 and ε2), can be calculated by looking up the system efficiency from a table based on the refrigerant flow rate and the high and low pressure ratio of the compressor.

[0122] The convective heat transfer coefficient k between the motor and the air can be obtained by looking up a table at different ambient temperatures and vehicle speeds. The motor efficiency η can be obtained by looking up a table based on the motor oil temperature and motor power.

[0123] Therefore, when the air source heat is sufficient and the electric drive heat is relatively small, the motor oil pump only meets the lubrication requirements. At this time, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the air source heat pump mode, which serves as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0124] In some embodiments, when switching to the air source heat pump mode, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to achieve switching of multiple heat pump modes, including: obtaining the first heat obtained by the compressor from the environment and the second heat dissipated by the motor to the environment; when the first heat is greater than or equal to the second heat, the air source heat pump mode is kept unchanged; when the first heat is less than the second heat, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the joint working mode of the air source heat pump and the motor waste heat heat pump.

[0125] According to the above embodiment, when the heat obtained from the environment is less than the heat dissipated by the motor to the environment, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the joint working mode of the air source heat pump and the motor waste heat heat pump, which serve as the low-temperature heat source of the heat pump to exchange heat with the refrigerant in the refrigerant circuit.

[0126] In some embodiments, when switching to the air source heat pump + motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to achieve switching of multiple heat pump modes, including: obtaining the inlet water temperature and the ambient temperature of the first heat exchanger; when the inlet water temperature is less than or equal to the ambient temperature, the air source heat pump and the motor waste heat heat pump work in the same mode; when the inlet water temperature is greater than the ambient temperature, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the motor waste heat heat pump mode.

[0127] In other words, the motor has sufficient heat. At this time, the motor acts as a low-temperature heat source, fully mobilizing the motor heat to participate in the vehicle's thermal management system, maximizing the utilization of the motor's waste heat, and maximizing the benefits of the vehicle-level thermal management system.

[0128] In some embodiments, when switching to the motor waste heat heat pump mode, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to achieve switching of multiple heat pump modes, including: obtaining the temperature of the battery; when the temperature of the battery is lower than the oil temperature of the motor, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the motor waste heat heat pump and the battery waste heat heat pump working together mode; when the temperature of the battery is greater than the preset temperature threshold, the multi-way valve, the first three-way valve assembly and the second three-way valve assembly are controlled to switch to the battery waste heat heat pump mode.

[0129] That is, when the battery temperature is lower than the oil temperature of motor 11, the excess heat is used to heat the battery, with the battery waste heat and motor waste heat acting as low-temperature heat sources. The system switches to a mode where the motor and battery waste heat heat pumps operate together. This allows for more precise switching between modes, taking into account the energy consumption differences of the vehicle across different modes, and maximizing the benefits of the thermal management system.

[0130] In some embodiments, the above-mentioned control method also includes: when switching to the air source heat pump mode, controlling the motor oil pump to operate at a preset speed; when switching to one of the motor waste heat heat pump mode, the air source heat pump and the motor waste heat heat pump working mode, and the motor waste heat heat pump and the battery waste heat heat pump working mode, determining the speed of the motor oil pump according to the target air outlet temperature of the heater core.

[0131] Specifically, in air-source heat pump mode, the motor oil pump only meets lubrication requirements, so its speed is relatively low. In motor waste heat heat pump mode, air-source heat pump + motor waste heat heat pump mode, or motor waste heat heat pump and battery waste heat heat pump working together, the motor, as a low-temperature heat source, needs to coordinately control the motor oil pump speed based on the heating capacity to control the amount of heat the motor can provide to the heat pump system. For example, based on the target outlet temperature of the heater core, the corresponding table is queried to obtain the motor oil pump speed. As shown in Table 1 above, when the target outlet temperature is 30°C, the corresponding motor oil pump speed is 2000 rad / s; when the target outlet temperature is 50°C, the corresponding motor oil pump speed is 4000 rad / s. This allows the motor oil pump speed to be actively controlled based on the amount of heat demand, removing more heat from the motor and maximizing the utilization of the motor's waste heat.

[0132] In a third aspect, the present disclosure provides a computer-readable storage medium storing a control program for a vehicle thermal management system. When the control program for the vehicle thermal management system is executed by a processor, the control method for the vehicle thermal management system in the above embodiment is implemented.

[0133] In a fourth aspect, the present disclosure provides a vehicle.

[0134] As shown in FIG10 , the vehicle 100 according to the embodiment of the present disclosure includes the vehicle thermal management system 110 described above.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure, and they should all be included in the scope of the claims and specification of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A vehicle thermal management system, comprising: A cooling oil circuit, a coolant circuit, a refrigerant circuit, a multi-way valve, and a controller. The coolant circuit includes: a first heat exchanger, a first three-way valve assembly, a battery, a second three-way valve assembly, and a second heat exchanger. The multi-way valve is used to selectively construct a fluid circuit so that heat is transferred from one or more of the first heat exchanger, the cooling oil circuit, and the battery to the second heat exchanger; The controller is configured to control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to achieve switching between multiple heat pump modes. The heat pump modes include: an air source heat pump mode, a motor waste heat heat pump mode, a mode of the air source heat pump and the motor waste heat heat pump working together, a mode of the motor waste heat heat pump and the battery waste heat heat pump working together, and a battery waste heat heat pump mode.

2. The vehicle thermal management system according to claim 1, wherein, The controller is configured to control the multi-way valve assembly, the first three-way valve assembly, and the second three-way valve assembly according to the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode, and the battery temperature to achieve switching between multiple heat pump modes.

3. The vehicle thermal management system according to claim 2, wherein, The cooling oil circuit includes a motor, a motor controller, a motor oil pump, and an oil cooler. The refrigerant circuit includes a compressor and a third heat exchanger. The first end of the multi-way valve is connected to the first end of the first three-way valve assembly through the oil cooler. The second end of the multi-way valve is connected to the second end of the first three-way valve assembly. The third end of the first three-way valve assembly is connected to the first heat exchanger. The third end of the multi-way valve is connected to one end of the first heat exchanger. The fourth end of the multi-way valve is connected to the first end of the second three-way valve assembly through the battery. The fifth end of the multi-way valve is connected to the second end of the second three-way valve assembly. The sixth end of the multi-way valve is connected to one end of the second heat exchanger. The other end of the second heat exchanger is connected to the third end of the second three-way valve assembly. The seventh end of the multi-way valve is connected to the heater core of the passenger compartment. The eighth end of the multi-way valve is connected to the heater core through the third heat exchanger.

4. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is the air source heat pump mode, the controller is configured to control the second end and the third end of the first three-way valve assembly to be connected, and control the second end and the fifth end of the multi-way valve to be connected, the third end and the sixth end of the multi-way valve to be connected, the seventh end and the eighth end of the multi-way valve to be connected, and control the second end and the third end of the second three-way valve assembly to be connected.

5. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is the mode of the air source heat pump and the motor waste heat heat pump working together, the controller is configured to control the first end and the second end of the first three-way valve assembly to be connected, and control the first end and the fifth end of the multi-way valve to be connected, the third end and the sixth end of the multi-way valve to be connected, the seventh end and the eighth end of the multi-way valve to be connected, and control the second end and the third end of the second three-way valve assembly to be connected.

6. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is the motor waste heat heat pump mode, the controller is configured to Control the first end and the second end of the first three-way valve assembly to communicate, and control the first end and the fifth end of the multi-way valve to communicate, the second end and the sixth end to communicate, the seventh end and the eighth end to communicate, and control the second end and the third end of the second three-way valve assembly to communicate.

7. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is the co - working mode of the motor waste heat heat pump and the battery waste heat heat pump, the controller is configured to, Control the first end and the second end of the first three-way valve assembly to communicate, and control the first end and the fourth end of the multi-way valve to communicate, the second end and the sixth end to communicate, the seventh end and the eighth end to communicate, and control the first end and the third end of the second three-way valve assembly to communicate.

8. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is the battery waste heat heat pump mode, the controller is configured to, Control the second end and the third end of the first three-way valve assembly to communicate, and control the second end and the third end of the multi-way valve to communicate, the fourth end and the sixth end to communicate, the seventh end and the eighth end to communicate, and control the first end and the third end of the second three-way valve assembly to communicate.

9. The vehicle thermal management system according to any one of claims 2-8, wherein, The controller is configured to, When the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the air source heat pump mode; When the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the motor waste heat heat pump mode.

10. The vehicle thermal management system according to claim 9, wherein, When switching to the air source heat pump mode, the controller is further configured to, Obtain the first heat obtained by the compressor from the environment and the second heat dissipated by the motor to the environment; When the first heat is greater than or equal to the second heat, keep the air source heat pump mode unchanged; When the first heat is less than the second heat, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the co - working mode of the air source heat pump and the motor waste heat heat pump.

11. The vehicle thermal management system according to claim 10, wherein, When switching to the co - working mode of the air source heat pump and the motor waste heat heat pump, the controller is further configured to, Obtain the inlet water temperature of the first heat exchanger and the ambient temperature; When the inlet water temperature is less than or equal to the ambient temperature, keep the co - working mode of the air source heat pump and the motor waste heat heat pump unchanged; When the inlet water temperature is greater than the ambient temperature, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the motor waste heat heat pump mode.

12. The vehicle thermal management system according to claim 11, wherein, When switching to the motor waste heat heat pump mode, the controller is further configured to, Obtain the temperature of the battery; When the temperature of the battery is less than the oil temperature of the motor, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the co - working mode of the motor waste heat heat pump and the battery waste heat heat pump; When the temperature of the battery is greater than a preset temperature threshold, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to the battery waste heat heat pump mode.

13. The vehicle thermal management system according to claim 9, wherein, The controller is further configured to acquire the heating demand of the passenger compartment and the system efficiency; acquire the driving power required to maintain the target vehicle speed and the motor efficiency; determine the total system power consumption in the air source heat pump mode and the total system power consumption in the motor waste heat heat pump mode according to the sum of the ratio of the heating demand of the passenger compartment to the system efficiency and the ratio of the driving power to the motor efficiency; wherein, the system efficiency in the air source heat pump mode, the driving power required to maintain the target vehicle speed, and the motor efficiency are different from the system efficiency in the motor waste heat heat pump mode, the driving power required to maintain the target vehicle speed, and the motor efficiency.

14. The vehicle thermal management system according to any one of claims 2-8, wherein, The controller is further configured to when switching to the air source heat pump mode, control the motor oil pump to operate at a preset speed; when switching to one of the motor waste heat heat pump mode, the co - working mode of the air source heat pump and the motor waste heat heat pump, and the co - working mode of the motor waste heat heat pump and the battery waste heat heat pump, determine the speed of the motor oil pump according to the target air outlet temperature of the heater core.

15. A control method for a vehicle thermal management system according to any one of claims 1 - 14, the method comprising: acquire the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode, and the temperature of the battery; control the multi - way valve, the first three - way valve assembly, and the second three - way valve assembly according to the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode, and the temperature of the battery to achieve switching between multiple heat pump modes, wherein the heat pump modes include: air source heat pump mode, motor waste heat heat pump mode, co - working mode of the air source heat pump and the motor waste heat heat pump, co - working mode of the motor waste heat heat pump and the battery waste heat heat pump, and battery waste heat heat pump mode.

16. The control method according to claim 15, wherein, Controlling the multi - way valve, the first three - way valve assembly, and the second three - way valve assembly to achieve switching between multiple heat pump modes includes: when the total system power consumption in the air source heat pump mode is less than the total system power consumption in the motor waste heat heat pump mode, control the multi - way valve, the first three - way valve assembly, and the second three - way valve assembly to switch to the air source heat pump mode; when the total system power consumption in the air source heat pump mode is greater than or equal to the total system power consumption in the motor waste heat heat pump mode, control the multi - way valve, the first three - way valve assembly, and the second three - way valve assembly to switch to the motor waste heat heat pump mode.

17. The control method according to claim 16, wherein, When switching to the air source heat pump mode, controlling the multi - way valve, the first three - way valve assembly, and the second three - way valve assembly to achieve switching between multiple heat pump modes includes: acquire the first heat obtained by the compressor from the environment and the second heat dissipated by the motor to the environment; when the first heat is greater than or equal to the second heat, keep the air source heat pump mode unchanged; When the first heat quantity is less than the second heat quantity, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the co-working mode of the air source heat pump and the motor waste heat heat pump.

18. The control method according to claim 17, wherein, When switching to the co-working mode of the air source heat pump and the motor waste heat heat pump, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to realize the switching of multiple heat pump modes, including: Obtain the inlet water temperature and the ambient temperature of the first heat exchanger; When the inlet water temperature is less than or equal to the ambient temperature, keep the co-working mode of the air source heat pump and the motor waste heat heat pump unchanged; When the inlet water temperature is greater than the ambient temperature, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the motor waste heat heat pump mode.

19. The control method according to claim 18, wherein, When switching to the motor waste heat heat pump mode, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to realize the switching of multiple heat pump modes, including: Obtain the temperature of the battery; When the temperature of the battery is less than the oil temperature of the motor, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the co-working mode of the motor waste heat heat pump and the battery waste heat heat pump; When the temperature of the battery is greater than the preset temperature threshold, control the multi-way valve, the first three-way valve assembly and the second three-way valve assembly to switch to the battery waste heat heat pump mode.

20. The control method according to any one of claims 15-19, wherein, Obtain the total system power consumption in the air source heat pump mode, the total system power consumption in the motor waste heat heat pump mode and the temperature of the battery, including: Obtain the heating demand of the passenger compartment and the system efficiency; Obtain the driving power required to maintain the target vehicle speed and the motor efficiency; Determine the total system power consumption in the air source heat pump mode and the total system power consumption in the motor waste heat heat pump mode according to the sum of the ratio of the heating demand of the passenger compartment to the system efficiency and the ratio of the driving power to the motor efficiency; Wherein, the system efficiency in the air source heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency are different from the system efficiency in the motor waste heat heat pump mode, the driving power required to maintain the target vehicle speed and the motor efficiency.

21. The control method according to any one of claims 15-19, wherein, The method further includes: When switching to the air source heat pump mode, control the motor oil pump to run at a preset speed; When switching to one of the motor waste heat heat pump mode, the co-working mode of the air source heat pump and the motor waste heat heat pump, and the co-working mode of the motor waste heat heat pump and the battery waste heat heat pump, determine the speed of the motor oil pump according to the target outlet air temperature of the heater core.

22. A computer-readable storage medium, on which a control program of a vehicle thermal management system is stored. When the control program of the vehicle thermal management system is executed by a processor, it realizes the control method of the vehicle thermal management system according to any one of claims 15-21.

23. A vehicle, including the vehicle thermal management system according to any one of claims 1-14.

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