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 and its thermal management system, control method and storage medium

[0001] Relevant publicly available cross-references

[0002] This disclosure claims priority to Chinese Patent Application No. 202410018920X, filed on January 3, 2024, entitled "Vehicle and its thermal management system, control method and storage medium", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of vehicles, specifically to a vehicle thermal management system, a control method for a vehicle thermal management system, a computer-readable storage medium, and a vehicle. Background Technology

[0004] In order to simplify the system architecture and reduce system costs, current electric vehicle thermal management systems connect the LTR (Low Temperature Heat Exchanger) in series with the motor. By bypassing the LTR, a pure motor waste heat heat pump can be achieved. However, since the motor controller must ensure a certain cooling flow to prevent the controller from overheating, it is difficult to simultaneously achieve a pure LTR heat pump and motor heat storage mode. Even if it can be achieved, the required structure is very complex, which not only increases hardware costs but also makes later maintenance inconvenient.

[0005] Public content

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

[0007] In a first aspect, this disclosure provides a vehicle thermal management system, including: 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 the fluid circuit, transferring heat 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 pump mode, an air source heat pump + motor waste heat pump mode, a combined motor waste heat pump and battery waste heat pump mode, and a battery waste heat pump mode.

[0008] In the technical solution of this disclosure embodiment, a multi-way valve is used in conjunction with two three-way valve assemblies in the coolant circuit to switch the connection relationship, thereby realizing the switching of multiple heat pump modes, 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, thereby enabling switching between multiple heat pump modes. This allows for mode switching of the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly based on the energy consumption differences between different vehicle modes, maximizing the efficiency 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 a multi-way valve is connected to the first end of a first three-way valve assembly via 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 a second three-way valve assembly via 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 the heating core of the passenger compartment; and the eighth end of the multi-way valve is connected to the heating core via the third heat exchanger. The motor controller is placed on the lubricating oil circuit, sharing the same circuit with the oil-cooled motor, and both use the oil cooler for heat exchange with the outside environment.

[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 connect with the third end, control the second end of the multi-way valve to connect with the fifth end, the third end to the sixth end, the seventh end to the eighth end, and control the second end of the second three-way valve assembly to connect with the third end.

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

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

[0015] In some embodiments, when the heat pump mode is a battery waste heat heat pump mode, the controller is configured to control the connection between the second and third ends of the first three-way valve assembly, control the connection between the second and third ends, the fourth and sixth ends, and the seventh and eighth ends of the multi-way valve, and control the connection between the first and third ends of the second three-way valve assembly. This allows the connection relationships of 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, thereby switching to the corresponding heat pump mode.

[0016] 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 to switch to air source heat pump mode when the total system power consumption in air source heat pump mode is less than that in motor waste heat heat pump mode; and to control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to motor waste heat heat pump mode when the total system power consumption in air source heat pump mode is greater than or equal to that in motor waste heat heat pump mode. When the air source heat is sufficient and the electric drive heat is relatively low, the motor oil pump only meets the lubrication requirements. In this case, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to air source heat pump mode allows the heat pump to act as a low-temperature heat source for heat exchange with the refrigerant in the refrigerant circuit.

[0017] In some embodiments, when switching to air source heat pump mode, the controller is further configured to acquire a first heat source from the environment and a second heat source dissipated by the motor to the environment; if the first heat source is greater than or equal to the second heat source, maintain the air source heat pump mode; if the first heat source is less than the second heat source, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to a combined air source heat pump and motor waste heat pump operating mode. When the heat source acquired from the environment is less than the heat dissipated by the motor to the environment, control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to a combined air source heat pump and motor waste heat pump operating mode, serving 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 combined air-source heat pump and motor waste heat pump operating mode, the controller is further configured to acquire 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, maintain the combined air-source heat pump and motor waste heat pump operating mode; 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 pump mode. With ample heat from the motor, the motor acts as a low-temperature heat source, fully utilizing its heat in the vehicle's thermal management system to maximize the utilization of motor waste heat and thus maximize the benefits of the vehicle-level thermal management system.

[0019] In some embodiments, when switching to the motor waste heat pump mode, the controller is further configured to acquire 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 where the motor waste heat pump and the battery waste heat pump operate simultaneously; 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 pump mode. This allows for a comprehensive consideration of the vehicle's energy consumption differences between different modes, enabling more precise switching between modes and maximizing the efficiency of the thermal management system.

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

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

[0022] Secondly, this disclosure provides a control method for a vehicle thermal management system. The method includes: acquiring the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat pump mode, and the battery temperature; controlling a multi-way valve, a first three-way valve assembly, and a 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 pump mode, and the battery temperature to achieve switching between multiple heat pump modes. The heat pump modes include: air source heat pump mode, motor waste heat pump mode, a combined air source heat pump and motor waste heat pump mode, a combined motor waste heat pump and battery waste heat pump mode, and a battery waste heat pump mode.

[0023] In the technical solution of this disclosure embodiment, 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 pump mode, and the battery temperature, so as to realize the switching of multiple heat pump modes. The energy consumption difference of the whole vehicle between different modes is taken into account. For example, the difference in vehicle resistance caused by the front fan being turned on when the air source heat pump is in operation and the front fan being turned off when the waste heat pump (battery waste heat pump or motor waste heat pump) is in operation is more accurate, thereby realizing the switching between various modes more precisely and maximizing the benefits of the whole vehicle-level thermal management system.

[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. This includes: when the total system power consumption in air source heat pump mode is less than the total system power consumption in motor waste heat heat pump mode, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to air source heat pump mode; and when the total system power consumption in air source heat pump mode is greater than or equal to the total system power consumption in motor waste heat heat pump mode, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to motor waste heat heat pump mode. When the air source heat is sufficient and the electric drive heat is relatively low, the motor oil pump only meets lubrication requirements. In this case, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to air source heat pump mode allows the air source to act as a low-temperature heat source for the heat pump, exchanging heat with the refrigerant in the refrigerant circuit.

[0025] In some embodiments, when switching to 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: acquiring a first heat source from the environment and a second heat source dissipated by the motor to the environment; maintaining the air source heat pump mode unchanged when the first heat source is greater than or equal to the second heat source; and controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to a combined air source heat pump and motor waste heat pump operating mode when the first heat source is less than the second heat source. When the heat source acquired 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 combined air source heat pump and motor waste heat pump operating mode, 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 combined air-source heat pump and motor waste heat pump operating mode, 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. This includes: acquiring the inlet water temperature of the first heat exchanger and the ambient temperature; maintaining the combined air-source heat pump and motor waste heat pump operating mode when the inlet water temperature is less than or equal to the ambient temperature; and 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 pump mode when the inlet water temperature is greater than the ambient temperature. The motor has ample heat, and as a low-temperature heat source, it fully utilizes its heat in the vehicle's thermal management system, maximizing the utilization of motor waste heat and thus maximizing the efficiency 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. This includes: acquiring the battery temperature; when the battery temperature is lower than the motor oil 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 + battery waste heat heat pump mode; and when the battery temperature is higher than a preset temperature threshold, controlling 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 a comprehensive consideration of the vehicle's energy consumption differences between different modes, enabling more precise switching between modes and maximizing the efficiency of the thermal management system.

[0028] In some embodiments, 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 includes: obtaining the passenger compartment heating demand and system efficiency; obtaining the drive 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 sum of the ratio of passenger compartment heating demand to system efficiency and the ratio of drive power to motor efficiency; wherein the system efficiency, drive power, and motor efficiency required to maintain the target vehicle speed in air source heat pump mode are different from those in motor waste heat heat pump mode.

[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 outlet air temperature of the heater core when switching to one of the following modes: motor waste heat pump mode, air source heat pump and motor waste heat pump working together mode, or motor waste heat pump and battery waste heat pump working together mode. This allows for proactive control of the motor oil pump speed according to the amount of heat demand, removing more heat from the motor and maximizing the utilization of motor waste heat.

[0030] Thirdly, this disclosure provides a computer-readable storage medium storing a control program for a vehicle thermal management system thereon, which, when executed by a processor, implements the control method for the vehicle thermal management system in the above embodiments.

[0031] Fourthly, this disclosure provides a vehicle including the aforementioned vehicle thermal management system.

[0032] The above description is merely an overview of the technical solution disclosed herein. In order to better understand the technical handpiece of this disclosure and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this disclosure more apparent and understandable, specific embodiments of this disclosure are described below. Attached Figure Description

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0034] Figure 1 is a schematic diagram of the structure of a vehicle thermal management system according to some embodiments of the present disclosure;

[0035] Figure 2 is a schematic diagram of the structure of a vehicle thermal management system according to some embodiments of the present disclosure;

[0036] Figure 3 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0037] Figure 4 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0038] Figure 5 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of this disclosure;

[0039] Figure 6 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0040] Figure 7 is a schematic diagram of mode switching of a vehicle thermal management system according to some embodiments of the present disclosure;

[0041] Figure 8 is a flowchart of a control method for a vehicle thermal management system according to some embodiments of the present disclosure;

[0042] Figure 9 is a flowchart of a control method for a vehicle thermal management system according to some embodiments of the present disclosure;

[0043] Figure 10 is a block diagram of a vehicle according to some embodiments of the present disclosure. Detailed Implementation

[0044] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and foregoing description of the drawings of this disclosure are intended to cover non-exclusive inclusion.

[0046] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

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

[0048] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0049] In the description of the embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0050] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0051] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0052] In order to simplify the system architecture and reduce system costs, current electric vehicle thermal management systems connect the LTR (Low Temperature Heat Exchanger) in series with the motor. By bypassing the LTR, a pure motor waste heat heat pump can be achieved. However, since the motor controller must ensure a certain cooling flow to prevent the controller from overheating, it is difficult to simultaneously achieve a pure LTR heat pump and motor heat storage mode. Even if it can be achieved, the required structure is very complex, which not only increases hardware costs but also makes later maintenance inconvenient.

[0053] Secondly, current thermal management systems generally allow selection between multiple heat sources, with numerous corresponding heat pump modes, such as pure LTR heat pumps, motor waste heat electric pumps, and LTR + motor waste heat heat pumps. How to optimize the control algorithm to more accurately switch between various modes from the perspective of overall vehicle energy gain and maximize the benefits of the thermal management system has become an industry challenge.

[0054] To address this, this disclosure constructs a water-based thermal management system architecture. Controller components such as the motor controller and on-board charger utilize an oil-cooling solution, sharing a common circuit with the oil-cooled motor and exchanging heat with the external environment via the same oil cooler. Multiple heat pump modes are achieved through a single eight-way valve, including a pure LTR heat pump, a motor waste heat pump, LTR and motor waste heat pump working together, motor and battery waste heat pump working together, and a battery waste heat pump. While simplifying the system architecture, this design still achieves a rich variety of heat pump modes, perfectly combining low cost and high performance.

[0055] For ease of explanation, the following embodiments use a vehicle thermal management system according to some embodiments of this disclosure as an example.

[0056] Referring to Figure 1, this disclosure provides a vehicle thermal management system, which may include: a cooling oil circuit (shown by dashed lines in the figure), a coolant circuit (shown by solid lines in the figure), a refrigerant circuit (shown by dotted lines in the figure), a multi-way valve 40, and a controller (not specifically shown in the figure). 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. The first end of the multi-way valve 40 is connected to the first end of the first three-way valve assembly 22 via the oil cooler 14. The second end of the multi-way valve 40 is connected to the second end of the first three-way valve assembly 22. The third end of the first three-way valve assembly 22 is connected to the first heat exchanger 21. The third end of the multi-way valve 40 is connected to the first heat exchanger 25. One end of the multi-way valve 40 is connected to the first end of the second three-way valve assembly 24 via the battery 23, the fifth end of the multi-way valve 40 is connected to the second end of the second three-way valve assembly 24, the sixth end of the multi-way valve 40 is connected to one end of the second heat exchanger 25, the other end of the second heat exchanger 25 is connected to the third end of the second three-way valve assembly 24, the seventh end of the multi-way valve 40 is connected to the heating core of the passenger compartment, and the eighth end of the multi-way valve 40 is connected to the heating core via the third heat exchanger 32. 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 achieve switching between multiple heat pump modes, including: air source heat pump mode, motor waste heat pump mode, air source heat pump and motor waste heat pump working mode, motor waste heat pump and battery waste heat pump working mode, and battery waste heat pump mode.

[0057] In the technical solution of this embodiment, 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 via 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 via 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 via 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 port of the compressor.

[0058] In this system, the lubricating oil in the lubricating oil circuit exchanges heat with the coolant in the coolant circuit through the oil cooler 14. The coolant in the coolant circuit exchanges heat with the refrigerant in the refrigerant circuit through the second heat exchanger 25. The refrigerant in the refrigerant circuit exchanges heat with the heating core of the passenger compartment through the third heat exchanger 32, thus meeting the needs of the passenger compartment through the heating core. The heat pump mode is switched by adjusting the connection state of the multi-way valve 40, the connection direction of the first three-way valve assembly 22, and the connection state of the second three-way valve assembly 24. Therefore, by placing the motor controller on the lubricating oil circuit, sharing the same circuit with the oil-cooled motor, and using the oil cooler together for heat exchange with the outside environment, a single multi-way valve, in conjunction with two three-way valve assemblies in the coolant circuit, can switch between multiple heat pump modes, simplifying the system architecture, enriching the heat pump modes, reducing system costs, and improving 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 air-source heat pump mode, the total system power consumption in motor waste heat heat pump mode, and the battery temperature, thereby enabling switching between multiple heat pump modes. This allows for mode switching of the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly based on the energy consumption differences between different vehicle modes, maximizing the efficiency 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 which is connected to the fourth end of the oil cooler 14, and the other end of which is connected to the first end of the multi-way valve 40. Since the motor 11 has low-efficiency operation and stalled overheating function, the PTC heater can be eliminated, reducing system costs.

[0062] To facilitate the demonstration of various mode switching methods, in the following embodiments, the lubricating oil circuit, refrigerant circuit, and coolant circuit are all represented by solid lines, while dashed lines represent unconnected parts. Furthermore, the following explanation uses a PTC heater as an example; it should be noted that the heat pump mode switching described below can also be achieved by omitting the PTC heater from the thermal management system.

[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 connect with the third end, control the second end of the multi-way valve 40 to connect with the fifth end, the third end to the sixth end, the seventh end to the eighth end, and control the second end of the second three-way valve assembly 24 to connect with the third end.

[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 form 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 as follows: first heat exchanger 21 → first three-way valve assembly 22 (third end and second end connected) → multi-way valve (second end and fifth end connected) → second three-way valve assembly 24 (second end and third end connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth end and third end connected) → second water pump 27 → first heat exchanger 21; third heat exchanger 32 → third water pump 28 → heater core 50 → multi-way valve (seventh end and eighth end connected) → third heat exchanger 32; motor 11, motor controller 12, oil cooler 14, and motor oil pump 13 constitute the 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 cabin through the heater core.

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

[0066] In some embodiments, when the heat pump mode is a combined operation mode of air source heat pump and motor waste heat heat pump, the controller is configured to control the first end of the first three-way valve assembly to connect with the second end, control the first end of the multi-way valve to connect with the fifth end, the third end to the sixth end, the seventh end to the eighth end, and control the second end of the second three-way valve assembly to connect with 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 to each other as the low-temperature heat source of the heat pump (the air source heat pump and the motor waste heat heat pump work together). The connection direction of the air source heat pump and the motor waste heat pump working together is as follows: First heat exchanger 21 → First three-way valve assembly 22 (the third end is connected to the first end) → Oil cooler 14 → PTC heater 29 → Multi-way valve 40 (the first end is connected to the fifth end) → Second three-way valve assembly 24 (the second end is connected to the third end) → Second heat exchanger 25 → First water pump 26 → Multi-way valve 40 (the sixth end is connected to the third end) → Second water pump 27 → First heat exchanger 21; 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 is connected to the eighth end) → 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. The refrigerant circuit then exchanges heat with the heater core through the third heat exchanger 32. The heat is then transferred to the passenger cabin 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 connect with the second end, control the first end of the multi-way valve to connect with the fifth end, the second end to connect with the sixth end, the seventh end to connect with the eighth end, and control the second end of the second three-way valve assembly to connect with the third end.

[0069] Specifically, as shown in Figure 5, the first three-way valve assembly 22, oil cooler 14, PTC heater 29, multi-way valve 40, second three-way valve assembly 24, second heat exchanger 25, and first water pump 26 are connected as the low-temperature heat source of the heat pump (motor waste heat heat pump mode). The connection direction of the motor waste heat heat pump mode is as follows: oil cooler 14 → PTC heater 29 → multi-way valve 40 (first end and fifth end connected) → second three-way valve assembly 24 (second end and third end connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth end and second end connected) → first three-way valve assembly 22 (second end and first end 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 end and eighth end 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. The refrigerant circuit then exchanges heat with the heater core through the third heat exchanger 32. The heat is then transferred to the passenger cabin through the heater core.

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

[0071] Specifically, as shown in Figure 6, the oil cooler 14, PTC heater 29, multi-way valve 40, battery 23, second three-way valve assembly 24, second heat exchanger 25, first water pump 26, and first three-way valve assembly 22 are connected to serve as the low-temperature heat source of the heat pump (the motor waste heat heat pump and the battery waste heat heat pump work together). The connection direction of the motor waste heat pump and the battery waste heat pump working together is as follows: oil cooler 14 → PTC heater 29 → multi-way valve 40 (first end and fourth end connected) → battery 23 → second three-way valve assembly 24 (first end and third end connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth end and second end connected) → first three-way valve assembly 22 (second end and first end 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 end and eighth end 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. The refrigerant circuit then exchanges heat with the heater core through the third heat exchanger 32. The heat is then transferred to the passenger cabin through the heater core.

[0072] In some embodiments, when the heat pump mode is a battery waste heat heat pump mode, the controller is configured to control the connection between the second and third ends of the first three-way valve assembly, control the connection between the second and third ends, the fourth and sixth ends, and the seventh and eighth ends of the multi-way valve, and control the connection between the first and third ends of the second three-way valve assembly. This allows the connection relationships of 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, thereby switching 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 as a low-temperature heat source for the heat pump (battery waste heat heat pump mode). The connection direction of the battery waste heat heat pump mode is as follows: battery 23 → second three-way valve assembly 24 (first end and third end connected) → second heat exchanger 25 → first water pump 26 → multi-way valve 40 (sixth end and fourth end connected) → battery 23; third heat exchanger 32 → third water pump 28 → warm air core 50 → multi-way valve 40 (seventh end and eighth end connected) → third heat exchanger 32; first heat exchanger 21 → first three-way valve assembly 22 (third end and second end connected) → multi-way valve 40 (second end and third end 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 exchanges heat with the heater core 50 through the third heat exchanger 32, and the heat is transferred to the passenger cabin 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 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 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 pump mode.

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

[0076] Specifically, the first step is to obtain the passenger cabin heating demand Q0, where Q0 = air density ρ * air volume of the air conditioning unit * (air conditioning unit outlet enthalpy - inlet enthalpy). The target outlet temperature can be calculated by the air conditioning heat load algorithm. The drive 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 In air source heat pump mode, the drive power P1 required to maintain the target vehicle speed is calculated. The motor oil temperature after the motor's own heat storage stabilizes is T1, at which point the corresponding motor efficiency is η1. The heat pump absorbs heat from the environment, and the system efficiency (heat pump system efficiency) is ε1. Therefore, the total system power consumption in air source heat pump mode can be obtained. The first heat the compressor extracts from the environment The second heat Q emitted by the motor to the environment p1 =A·k·(T1-T0). Where T0 represents the ambient temperature, A represents the heat dissipation surface area of ​​the motor, and k represents the convective heat transfer coefficient with air.

[0078] According to the principle of conservation of energy In the waste heat heat pump mode of the motor, the drive power P2 required to maintain the target vehicle speed is calculated (since the front fan (the front fan is the fan set for the first heat exchanger) is turned off, the resistance is reduced, so P2 < P1). The motor oil temperature after the motor itself has stabilized due to heat storage is T2, and the corresponding motor efficiency 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 waste heat heat pump mode of the motor can be obtained. Alternatively, the system efficiency ε (including ε1 and ε2) can be calculated by determining the steady-state airflow in the passenger cabin based on the target set temperature and ambient temperature, and then looking up the system efficiency in a table based on the steady-state airflow. Another method is to calculate the system efficiency ε (including ε1 and ε2) based on the refrigerant flow rate and the high-low pressure ratio of the compressor, and then looking up the system efficiency in a table.

[0079] The convective heat transfer coefficient k between the motor and the air can be obtained from a table under different ambient temperatures and vehicle speeds. The motor efficiency η can be obtained from 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 low, 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 air source heat pump mode, the controller is further configured to acquire a first heat source obtained by the compressor 31 from the environment and a second heat source dissipated by the motor 11 to the environment; if the first heat source is greater than or equal to the second heat source, maintain the air source heat pump mode unchanged; if the first heat source is less than the second heat source, control 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 air source heat pump and the motor waste heat heat pump work together.

[0082] According to the above embodiments, when the heat obtained from the environment is less than the heat dissipated from 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 pump mode, the controller is further configured to acquire the inlet water temperature and ambient temperature of the first heat exchanger 21; when the inlet water temperature is less than or equal to the ambient temperature, maintain the air source heat pump and motor waste heat pump working mode unchanged; when the inlet water temperature is greater than the ambient temperature, 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 pump mode.

[0084] In other words, the motor has plenty of heat. At this time, the motor acts as a low-temperature heat source, fully utilizing its heat to participate in the vehicle's thermal management system, thereby 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 pump mode, the controller is further configured to: acquire the temperature of the battery 23; control the multi-way valve 40, the first three-way valve assembly 22, and the second three-way valve assembly 24 when the temperature of the battery 23 is lower than the oil temperature of the motor 11, to switch to a mode where the motor waste heat pump and the battery waste heat pump work together; and control the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly when the temperature of the battery 23 is higher than a preset temperature threshold, to switch to the battery waste heat pump mode. The preset temperature threshold can be calibrated according to actual conditions.

[0086] In other words, when the battery temperature is lower than the oil temperature of motor 11, the excess heat is used to heat the battery. The waste heat from the battery and motor serves as a low-temperature heat source, switching to a combined operation mode of motor waste heat pump and battery waste heat pump. When the battery temperature is heated above a preset temperature threshold, indicating that the battery heat source is sufficient, the waste heat from battery 23 serves as a low-temperature heat source, switching to battery waste heat pump mode. This allows for a comprehensive consideration of the vehicle's energy consumption differences between different modes, enabling more precise switching between modes and maximizing the efficiency of the thermal management system.

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

[0088] Specifically, in air source heat pump mode, the motor oil pump 13 only meets lubrication requirements, hence its relatively low speed. In motor waste heat pump mode, combined air source and motor waste heat pump mode, and combined motor and battery waste heat pump mode, the motor, as a low-temperature heat source, needs to coordinately control the motor oil pump speed according to the heating capacity to control the heat that the motor can provide to the heat pump system. For example, the motor oil pump speed can be obtained by consulting a relevant table based on the target outlet temperature of the heater core, as shown in Table 1.

[0089] Table 1

[0090] As shown in Table 1, when the target outlet air temperature is 30℃, the corresponding motor oil pump speed is 2000 rad / s; when the target outlet air temperature is 50℃, the corresponding motor oil pump speed is 4000 rad / s. Therefore, the motor oil pump speed can be actively controlled according to the amount of heat demand, removing more heat from the motor and maximizing the utilization of the motor's waste heat.

[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 taken as the final speed of the motor oil pump.

[0092] As a specific example, as shown in Figure 8, the control method of a vehicle thermal management system may include the following steps:

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

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

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

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

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

[0098] S106, determine whether W1 < W2 is true. If yes, proceed to step S107; otherwise, proceed to step S113.

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

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

[0101] S109, determine whether Qc1 < Qp1 is true. If yes, proceed to step S110; otherwise, return to step S107.

[0102] S110, switch to the working mode of air source heat pump and motor waste heat heat pump working together.

[0103] S111, obtain the inlet water 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 no, return to step S110.

[0105] S113, switch to 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 yes, proceed to step S116; if no, proceed to step S117.

[0108] S116, switch to the working mode of motor waste heat pump and battery waste heat pump working together.

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

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

[0111] In summary, the technical solution of this disclosure uses a multi-way valve in conjunction with two three-way valve assemblies in the coolant circuit to switch the connection relationship, thereby realizing the switching of multiple heat pump modes, simplifying the system architecture, enriching the heat pump modes, reducing system costs, and improving system performance.

[0112] Secondly, this disclosure provides a control method for a vehicle thermal management system.

[0113] As shown in Figure 9, the control method of the vehicle thermal management system according to this embodiment includes the following steps:

[0114] S1 obtains 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 based on the total system power consumption in air source heat pump mode, the total system power consumption in motor waste heat pump mode, and the battery temperature to achieve switching between multiple heat pump modes. The heat pump modes include: air source heat pump mode, motor waste heat pump mode, air source heat pump and motor waste heat pump working mode, motor waste heat pump and battery waste heat pump working mode, and battery waste heat pump mode.

[0116] In the technical solution of this disclosure embodiment, 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 pump mode, and the battery temperature, so as to realize the switching of multiple heat pump modes. The energy consumption difference of the whole vehicle between different modes is taken into account. For example, the difference in vehicle resistance caused by the front fan being turned on when the air source heat pump is in operation and the front fan being turned off when the waste heat pump (motor waste heat pump or battery waste heat pump) is in operation is more accurate, thereby realizing the switching between various modes more precisely and maximizing the benefits of the whole vehicle-level thermal management system.

[0117] 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, controlling 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; and 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, 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.

[0118] In some embodiments, 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 includes: obtaining the passenger compartment heating demand and system efficiency; obtaining the drive 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 sum of the ratio of passenger compartment heating demand to system efficiency and the ratio of drive power to motor efficiency; wherein the system efficiency, drive power, and motor efficiency required to maintain the target vehicle speed in air source heat pump mode are different from those in motor waste heat heat pump mode.

[0119] Specifically, the first step is to obtain the passenger cabin heating demand Q0, where Q0 = air density ρ * air volume of the air conditioning unit * (air conditioning unit outlet enthalpy - inlet enthalpy). The target outlet temperature can be calculated by the air conditioning heat load algorithm. The drive 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 In air source heat pump mode, the drive power P1 required to maintain the target vehicle speed is calculated. The motor oil temperature after the motor's own heat storage stabilizes is T1, at which point the corresponding motor efficiency is η1. The heat pump absorbs heat from the environment, and the system efficiency is ε1. Therefore, the total system power consumption in air source heat pump mode can be obtained. The first heat the compressor extracts from the environment The second heat Q emitted by the motor to the environment p1 =A·k·(T1-T0). Where T0 represents the ambient temperature, A represents the heat dissipation surface area of ​​the motor, and k represents the convective heat transfer coefficient with air.

[0121] According to the principle of conservation of energy In the waste heat heat pump mode of the motor, the drive power P2 required to maintain the target vehicle speed is calculated (since the front fan (the front fan is the fan set for the first heat exchanger) is turned off, the resistance is reduced, so P2 < P1). The motor oil temperature after the motor itself has stabilized due to heat storage is T2, and the corresponding motor efficiency 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 waste heat heat pump mode of the motor can be obtained. Alternatively, the system efficiency ε (including ε1 and ε2) can be calculated by determining the steady-state airflow in the passenger cabin based on the target set temperature and ambient temperature, and then looking up the system efficiency in a table based on the steady-state airflow. Another method is to calculate the system efficiency ε (including ε1 and ε2) based on the refrigerant flow rate and the high-low pressure ratio of the compressor, and then looking up the system efficiency in a table.

[0122] The convective heat transfer coefficient k between the motor and the air can be obtained from a table under different ambient temperatures and vehicle speeds. The motor efficiency η can be obtained from 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 low, the motor oil pump only meets the lubrication requirements. At this time, the control multi-way valve, the first three-way valve assembly and the second three-way valve assembly are switched 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 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: acquiring a first heat source obtained by the compressor from the environment and a second heat source dissipated by the motor to the environment; maintaining the air source heat pump mode unchanged when the first heat source is greater than or equal to the second heat source; and controlling 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 air source heat pump and the motor waste heat heat pump work together when the first heat source is less than the second heat source.

[0125] As described in the above embodiments, when the heat obtained from the environment is less than the heat dissipated from 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 working mode of the air source heat pump and the motor waste heat heat pump working together, so as to 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 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: acquiring 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, maintaining the air source heat pump and motor waste heat pump working mode unchanged; when the inlet water 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 pump mode.

[0127] In other words, the motor has plenty of heat. At this time, the motor acts as a low-temperature heat source, fully utilizing its heat to participate in the vehicle's thermal management system, thereby 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 between multiple heat pump modes, including: acquiring the battery temperature; when the battery temperature is lower than the motor oil temperature, controlling the multi-way valve, the first three-way valve assembly, and the second three-way valve assembly to switch to a mode where the motor waste heat heat pump and the battery waste heat pump work together; and when the battery temperature is higher than a preset temperature threshold, controlling 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.

[0129] In other words, when the battery temperature is lower than the oil temperature of the motor 11, the excess heat is used to heat the battery. The waste heat from the battery and the motor serves as a low-temperature heat source, switching to a mode where the motor waste heat pump and the battery waste heat pump work together. This allows for a comprehensive consideration of the vehicle's energy consumption differences between different modes, enabling more precise switching between modes and maximizing the efficiency of the thermal management system.

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

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

[0132] Thirdly, this disclosure provides a computer-readable storage medium storing a control program for a vehicle thermal management system thereon, which, when executed by a processor, implements the control method for the vehicle thermal management system in the above embodiments.

[0133] Fourthly, this disclosure provides a vehicle.

[0134] As shown in FIG10, the vehicle 100 of this embodiment 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 this disclosure, and not to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure, and they should all be covered within the scope of the claims and specification of this 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. This disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A vehicle thermal management system, comprising: The system includes a cooling oil circuit, a coolant circuit, a refrigerant circuit, a multi-way valve, and a controller. 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. The multi-way valve is used to selectively construct a fluid circuit such 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, wherein the heat pump modes include: air source heat pump mode, motor waste heat pump mode, air source heat pump and motor waste heat pump working mode, motor waste heat pump and battery waste heat pump working mode, and battery waste 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 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, so as 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 via 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 via 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 heating core of the passenger compartment. The eighth end of the multi-way valve is connected to the heating core via 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, The second end of the first three-way valve assembly is connected to the third end, and the second end of the multi-way valve is connected to the fifth end, the third end to the sixth end, the seventh end to the eighth end, and the second end of the second three-way valve assembly is connected.

5. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is a combined operation mode of the air source heat pump and the motor waste heat heat pump, the controller is configured to, The system controls the first end of the first three-way valve assembly to be connected to the second end, and controls 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 controls the second end of the second three-way valve assembly to be connected to the third end.

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, The system controls the first end of the first three-way valve assembly to be connected to the second end, and controls the first end of the multi-way valve to be connected to the fifth end, the second end to the sixth end, the seventh end to the eighth end, and the second end of the second three-way valve assembly to be connected to the third end.

7. The vehicle thermal management system according to claim 3, wherein, When the heat pump mode is a combined operation mode of the motor waste heat heat pump and the battery waste heat heat pump, the controller is configured to, The system controls the first end of the first three-way valve assembly to be connected to the second end, and controls 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 the first end of the second three-way valve assembly to be connected to the third end.

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, The system controls the second and third ends of the first three-way valve assembly to be connected, and controls the second and third ends, the fourth and sixth ends, and the seventh and eighth ends of the multi-way valve to be connected, as well as controls the first and third ends of the second three-way valve assembly to be connected.

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, 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.

10. The vehicle thermal management system according to claim 9, wherein, When switching to the air source heat pump mode, the controller is also configured to, The compressor acquires a first heat from the environment and the motor dissipates a second heat to the environment. When the first heat is greater than or equal to the second heat, the air source heat pump mode remains 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 working mode of the air source heat pump and the motor waste heat heat pump working together.

11. The vehicle thermal management system according to claim 10, wherein, When switching to the combined operation mode of the air source heat pump and the motor waste heat heat pump, the controller is also configured to, Obtain the inlet water temperature and 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 remain in the same working mode. When the inlet water temperature is higher 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.

12. The vehicle thermal management system according to claim 11, wherein, When switching to the motor waste heat heat pump mode, the controller is also configured to, Obtain 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 working mode of the motor waste heat pump and the battery waste heat pump working together. When the battery temperature exceeds 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.

13. The vehicle thermal management system according to claim 9, wherein, The controller is also configured to, Obtain the passenger cabin heating requirements and system efficiency; To obtain the drive power and motor efficiency required to maintain the target vehicle speed; Based on the ratio of the passenger cabin heating demand to the system efficiency and the sum of the ratio of the drive power to the motor efficiency, 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 are determined. The system efficiency, drive power required to maintain the target vehicle speed, and motor efficiency in the air source heat pump mode are different from those in the motor waste heat heat pump mode.

14. The vehicle thermal management system according to any one of claims 2-8, wherein, The controller is also configured to, When switching to the air source heat pump mode, the motor oil pump is controlled to run at a preset speed; When switching to one of the following modes: motor waste heat pump mode, air source heat pump and motor waste heat pump working together mode, or motor waste heat pump and battery waste heat pump working together mode, the speed of the motor oil pump is determined according to the target outlet air temperature of the heater core.

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

16. The control method according to claim 15, wherein, The multi-way valve, the first three-way valve assembly, and the second three-way valve assembly are controlled to achieve switching between various 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.

17. The control method according to claim 16, wherein, 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: The compressor acquires a first heat from the environment and the motor dissipates a second heat to the environment. When the first heat is greater than or equal to the second heat, the air source heat pump mode remains 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 working mode of the air source heat pump and the motor waste heat heat pump working together.

18. The control method according to claim 17, wherein, When switching to the combined operation mode of the air source heat pump and the motor waste heat heat pump, 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: Obtain the inlet water temperature and 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 remain in the same working mode. When the inlet water temperature is higher 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.

19. The control method according to claim 18, wherein, 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: Obtain the battery temperature; 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 working mode of the motor waste heat pump and the battery waste heat pump working together. When the battery temperature exceeds 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.

20. The control method according to any one of claims 15-19, wherein, Obtain 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, including: Obtain the passenger cabin heating requirements and system efficiency; To obtain the drive power and motor efficiency required to maintain the target vehicle speed; Based on the ratio of the passenger cabin heating demand to the system efficiency and the sum of the ratio of the drive power to the motor efficiency, 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 are determined. The system efficiency, drive power required to maintain the target vehicle speed, and motor efficiency in the air source heat pump mode are different from those in the motor waste heat heat pump mode.

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, the motor oil pump is controlled to run at a preset speed; When switching to one of the following modes: motor waste heat pump mode, air source heat pump and motor waste heat pump working together mode, or motor waste heat pump and battery waste heat pump working together mode, the speed of the motor oil pump is determined according to the target outlet air temperature of the heater core.

22. A computer-readable storage medium storing thereon a control program for a vehicle thermal management system, which, when executed by a processor, implements the control method for the vehicle thermal management system according to any one of claims 15-21.

23. A vehicle comprising a vehicle thermal management system as claimed in any one of claims 1-14.

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