Electric vehicle thermal management control method and electric vehicle

Abstract

The invention provides an electric vehicle heat management control method and an electric vehicle, and relates to the technical field of energy. The heat management control method is used for controlling a valve of a refrigerant loop of the electric vehicle to achieve heat supply of the electric vehicle, an inlet of a second valve is used for being connected with an outlet of a compressor and controlling the flow of compressed refrigerant output by the circulating compressor, and an outlet of the second valve is used for being connected with an inlet of the compressor. The heat management control method comprises the steps that an air conditioner starts to supply air under the condition that the air conditioner of the electric vehicle adjusts and increases the hot air volume at the first moment, and the first valve of the refrigerant loop is controlled to reduce the opening degree to a first preset valve opening degree, and controlling a second valve of the refrigerant loop to increase the opening degree to a second preset valve opening degree. In this way, when the external temperature is lower than the critical temperature of heat absorbed by the refrigerant, the heat management system can be controlled to achieve rapid and stable heat supply of the passenger compartment of the electric vehicle without using an electric heater.

Description

Technical Field

[0001] The present application relates to the field of energy technology, and in particular to a thermal management control method for an electric vehicle and an electric vehicle. Background Art

[0002] As an important part of electric vehicles, the thermal management system of electric vehicles is used to adjust the temperature of the power battery, powertrain and passenger compartment of electric vehicles. In the related art, when the outside temperature is low, electric heaters (positive temperature coefficient, PTC) or heat pumps are usually used to provide heat for the power battery, powertrain and passenger compartment in electric vehicles, so that the power battery and powertrain work at a suitable temperature, thereby driving the electric vehicle to run normally and providing users with a comfortable driving environment.

[0003] However, PTC not only takes up a large space and has a high cost, but also when the outside temperature is lower than the critical temperature at which the refrigerant absorbs heat (for example, minus 20 degrees Celsius or lower), the refrigerant in the thermal management system cannot absorb heat from the environment, which will cause heating fluctuations and poor stability.

[0004] Based on this, how to provide a low-cost thermal management control method to control the thermal management system to achieve rapid and stable heating of the passenger compartment of an electric vehicle has become a technical problem that needs to be solved. Summary of the invention

[0005] The present application provides an electric vehicle thermal management control method and an electric vehicle, which are used to achieve rapid and stable heating of the electric vehicle passenger compartment. For example, when the outside temperature is lower than the critical temperature at which the refrigerant absorbs heat, the thermal management system is controlled to achieve rapid and stable heating of the electric vehicle passenger compartment.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, a thermal management control method for an electric vehicle is provided, the thermal management control method being used to control the valve of a refrigerant circuit of the electric vehicle to achieve heating of the electric vehicle, the refrigerant circuit comprising a first valve, a second valve, a condenser, and a compressor, the compressor being used to compress and heat the refrigerant in the refrigerant circuit, the inlet of the second valve being used to be connected to the outlet of the compressor and to control the flow rate of the compressed refrigerant output by the compressor, the outlet of the second valve being used to be connected to the inlet of the compressor, the inlet of the condenser being used to be connected to the outlet of the compressor through the first valve, the outlet of the condenser being used to be connected to the inlet of the compressor, the first valve being used to control the flow rate of the compressed refrigerant output by the compressor, the condenser being used to heat the interior of the electric vehicle, the electric vehicle being in a low temperature environment, the thermal management control method comprising: at a first moment, when the air conditioner of the electric vehicle is adjusted to increase the hot air volume, the air conditioner starts to discharge air, the first valve of the refrigerant circuit is controlled to reduce the opening to a first preset valve opening, and the second valve of the refrigerant circuit is controlled to increase the opening to a second preset valve opening.

[0008] In the above technical solution, the air conditioning of the electric vehicle increases the hot air volume, which means that the electric vehicle currently has more heat demand inside and needs to increase the hot air volume to heat the passenger compartment, or when the electric vehicle is just started in a low temperature environment, the internal temperature is equal to the external ambient temperature, and the air conditioner is urgently needed to provide hot air to heat the passenger compartment. The air conditioning of the electric vehicle increases the hot air volume, which means that the current heating supply is increased, and the actual heat production of the compressor cannot immediately match the increased heating supply. In the case of the air conditioning of the electric vehicle increasing the hot air volume at the first moment, the first valve is controlled to reduce the opening, and the second valve is controlled to increase the opening, so that the refrigerant output from the compressor returns to the compressor inlet faster, avoiding the rapid decrease of the refrigerant pressure at the compressor inlet when the electric vehicle increases the hot air volume, ensuring that the compressor can stably supply heat, maintaining the stability of the triangle cycle to a certain extent, and improving the robustness of the triangle cycle.

[0009] Based on this, the electric vehicle thermal management control method provided in the embodiment of the present application can control the normal operation of the thermal management system of the electric vehicle without additionally setting up a PTC when the refrigerant in the refrigerant circuit cannot absorb heat from the outside (for example, the outside temperature is -20°C or lower), thereby achieving stable heating of the electric vehicle.

[0010] In any possible implementation of the first aspect, the refrigerant circuit includes a first heat exchanger, a first inlet of the first heat exchanger is used to be connected to the outlet of the compressor through a second valve, the first outlet of the first heat exchanger is used to be connected to the inlet of the compressor, the second inlet of the first heat exchanger is used to be connected to the outlet of the first water pump of the electric vehicle cooling circuit, the second outlet of the first heat exchanger is used to be connected to an interface of the multi-way valve of the electric vehicle cooling circuit, the first heat exchanger is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other, and the thermal management control method also includes: at a first moment, controlling the opening of the first water pump to be less than the first water pump opening threshold.

[0011] The above possible implementation method is that when the air conditioning adjustment of the electric vehicle increases the hot air volume at the first moment, the opening of the first water pump is controlled to be less than the first water pump opening threshold, that is, the opening of the first water pump is controlled to decrease. The coolant entering the first heat exchanger is small, and the heat that can be exchanged with the refrigerant in the first heat exchanger is limited. When the temperature of the coolant is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also limited, and the heat can still be retained more in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, it will also increase the refrigerant pressure and temperature at the inlet of the compressor, so that the heat generation of the compressor can be adapted to the increased heating demand as soon as possible, which is conducive to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby achieving stable heating of the electric vehicle.

[0012] In any possible implementation of the first aspect, the refrigerant circuit also includes an evaporator, a third valve, a fourth valve and a first pressure sensor, the outlet of the compressor is used to be connected to the inlet of the first valve and the inlet of the second valve respectively through the first pressure sensor, the first pressure sensor is used to measure the pressure of the compressed refrigerant output by the compressor, the inlet of the evaporator is used to be connected to the outlet of the condenser and the first outlet of the first heat exchanger respectively through the third valve and the compressed refrigerant circulates, the outlet of the evaporator is used to be connected to the inlet of the compressor, the evaporator is used to heat the interior of the electric vehicle, the inlet of the fourth valve is respectively connected to the outlet of the condenser and the first outlet of the first heat exchanger and the compressed refrigerant circulates, the outlet of the fourth valve is used to be connected to the inlet of the compressor, the third valve and the fourth valve are used to control the flow rate of the compressed refrigerant, and the thermal management control method also includes: at a second moment after the first moment, the air flow rate change of the air conditioner is greater than or equal to the first air flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the first pressure threshold, the third valve opening is controlled to be reduced to a third preset valve opening, and the fourth valve opening is controlled to be increased to a fourth preset valve opening.

[0013] In the above possible implementation method, at the second moment, the opening of the third valve is controlled to decrease, which can reduce the compressed refrigerant flow through the evaporator, and the opening of the fourth valve is controlled to increase, which can increase the compressed refrigerant flow returning to the compressor inlet, thereby increasing the refrigerant pressure and temperature at the compressor inlet, so that the heat production of the compressor can be adapted to the increased heating demand as soon as possible, which is beneficial to maintaining the stability of the compressor's triangular cycle, improving the robustness of the compressor's triangular cycle, and enabling the electric vehicle to be heated stably.

[0014] In any possible implementation of the first aspect, the refrigerant circuit also includes a second heat exchanger, a first inlet of the second heat exchanger is used to connect to the outlet of the fourth valve, a first outlet of the second heat exchanger is used to connect to the inlet of the compressor, a second inlet of the second heat exchanger is used to connect to the outlet of the second water pump of the electric vehicle cooling circuit, a second outlet of the second heat exchanger is used to connect to another interface of the multi-way valve, the second heat exchanger is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other, and the thermal management control method also includes: at the second moment, controlling the opening of the second water pump to be less than the second water pump opening threshold.

[0015] In the above possible implementation, at the second moment, the opening of the second water pump is controlled to be less than the second water pump opening threshold, the coolant entering the second water pump 112 is less, and the heat that can be exchanged with the refrigerant in the second heat exchanger is limited. When the temperature of the coolant is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also limited, and more heat can still be retained in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the refrigerant pressure and temperature at the inlet of the compressor will also be increased, so that the heat production of the compressor can be adapted to the increased heating demand as soon as possible, which is conducive to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby achieving stable heating of the electric vehicle.

[0016] In any possible implementation of the first aspect, the thermal management control method also includes: at a third moment after the second moment, the air outlet flow rate change of the air conditioner is less than a first air outlet flow rate threshold and the pressure change value of the first pressure sensor is less than the first pressure threshold, and the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening change less than the first opening change value.

[0017] In the above possible implementations, the change in the air flow rate of the air conditioner is less than the first air flow rate threshold, indicating that the current air flow rate of the air conditioner has reached a stable state, and the pressure change value of the first pressure sensor is less than the first pressure threshold, indicating that the compressed refrigerant pressure output by the compressor has reached a stable state. After adjusting the valves and water pumps at the first and second moments, the heat production of the engine and the heating demand have reached a balance at the third moment, and the triangular cycle of the compressor can be maintained stable without making significant adjustments to the valves in the refrigerant circuit, thereby achieving stable heating of the electric vehicle.

[0018] In any possible implementation of the first aspect, the refrigerant circuit also includes a fifth valve, which is used to be connected between the inlet and the outlet of the compressor, and the fifth valve is used to control the compressed refrigerant flowing from the outlet to the inlet of the compressor. The thermal management control method also includes: at the fourth moment before the first moment, the air-conditioning switch of the electric vehicle increases the change value of the hot air volume by a value greater than the first air volume change threshold, and controls the compressor to start and operate at the first speed; controls the fifth valve opening to increase to a fifth preset valve opening, controls the first valve opening to increase to a sixth preset valve opening, the fifth preset valve opening is greater than the sixth preset valve opening, and the sixth preset valve opening is greater than the first valve preset opening.

[0019] The above possible implementation method is to start the compressor at the fourth moment, control the compressor to work at the first speed, and open the fifth valve so that the refrigerant output from the compressor re-enters the compressor through the fifth valve. Since the refrigerant output from the compressor is compressed refrigerant after being compressed by the compressor, the pressure and temperature of the compressed refrigerant are higher than the pressure and temperature of the refrigerant at the inlet of the compressor. Therefore, when the compressed refrigerant flows to the inlet of the compressor through the fifth valve, the pressure and temperature of the refrigerant at the inlet of the compressor can be increased, so that the compressor can work normally. Opening the first valve can transfer the compressed refrigerant output from the compressor to the condenser, thereby transferring heat to the passenger compartment through the condenser.

[0020] In any possible implementation of the first aspect, the refrigerant circuit also includes an air-conditioning box damper, which is arranged on the same side of the condenser and the evaporator, and the air-conditioning box damper is used to guide the blowing toward the condenser and the evaporator. The thermal management control method also includes: after the fourth moment and before the first moment, controlling the middle position of the air-conditioning box damper of the air conditioner to face the evaporator.

[0021] The above possible implementation method is to point the middle position of the air-conditioning box damper towards the evaporator, which can avoid blowing a large amount of heat in the condenser into the passenger compartment, thereby avoiding that the heat carried by the compressed refrigerant is reduced too much, which will further lead to a decrease in the actual heating value of the compressor. The actual heating value of the compressor can be increased as soon as possible to balance the heating value of the passenger compartment, which is conducive to maintaining the triangular cycle of the compressor, thereby realizing stable heating of the electric vehicle.

[0022] In any possible implementation of the first aspect, the thermal management control method also includes: at a fifth moment after the third moment, the air-conditioning switch reduces the change value of the hot air volume by a value greater than the second air volume change threshold, controls the third valve opening to increase to a seventh preset valve opening, and controls the fourth valve opening to decrease to an eighth preset valve opening.

[0023] The above possible implementation method is, when the actual heating value of the compressor is greater than the heating value of the passenger compartment, the opening of the third valve is first controlled to increase and the opening of the fourth valve is controlled to decrease, so that more of the compressed refrigerant output from the compressor enters the evaporator rather than the second heat exchanger. Because the outside temperature is extremely low, the amount of heat that the refrigerant can absorb when evaporating in the evaporator is also limited. In this way, the refrigerant transmitted to the inlet of the compressor will not cause large refrigerant pressure and fluctuations at the inlet of the compressor, which maintains the stability of the triangle cycle to a certain extent, can improve the robustness of the triangle cycle, and enable the electric vehicle to still provide stable heating.

[0024] In any possible implementation of the first aspect, the thermal management control method also includes: at a sixth moment after the fifth moment, the air outlet flow rate change of the air conditioner is greater than or equal to a second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, controlling the first valve opening to increase to a ninth preset valve opening, and reducing the second valve opening to a tenth preset valve opening.

[0025] The above possible implementation method is, when the actual heating value of the compressor is greater than the heating value of the passenger compartment, controlling the opening of the first valve to be greater than the opening of the second valve, so that more of the refrigerant output from the compressor enters the condenser rather than the first heat exchanger, and the blower blows the heat in the condenser to the passenger compartment, so that more of the heat carried by the compressed refrigerant is blown into the passenger compartment, reducing the refrigerant pressure and temperature at the compressor inlet, maintaining the stability of the triangle cycle to a certain extent, improving the robustness of the triangle cycle, so that the electric vehicle can still provide stable heating.

[0026] In any possible implementation of the first aspect, the thermal management control method also includes: at a seventh moment after the sixth moment, the air outlet flow rate change of the air conditioner is greater than or equal to a second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, and the opening of the second water pump is controlled to be greater than a third water pump opening threshold.

[0027] In the above possible implementation, at the seventh moment, the opening of the second water pump is controlled to be greater than the third water pump opening threshold, the amount of coolant entering the second heat exchanger increases, and the amount of heat that can be exchanged with the refrigerant in the second heat exchanger increases. When the temperature of the coolant is lower than the temperature of the refrigerant, more heat is exchanged out of the refrigerant, and the amount of heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the refrigerant pressure and temperature at the inlet of the compressor will not increase significantly, so that the actual heating value of the compressor can be matched with the reduced heating value of the passenger compartment as soon as possible, which is conducive to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby achieving stable heating of the electric vehicle.

[0028] In any possible implementation of the first aspect, the thermal management control method further includes: at a seventh moment, controlling the opening degree of the first water pump to be greater than a fourth water pump opening degree threshold.

[0029] In the above possible implementation, at the seventh moment, the opening of the first water pump is greater than the fourth water pump opening threshold, the amount of coolant entering the first heat exchanger increases, and the amount of heat that can be exchanged with the refrigerant in the first heat exchanger increases. When the temperature of the coolant is lower than the temperature of the refrigerant, more heat is exchanged out of the refrigerant, and the amount of heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the refrigerant pressure and temperature at the inlet of the compressor will not increase significantly, so that the actual heating value of the compressor can be matched with the reduced heating value of the passenger compartment as soon as possible, which is conducive to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby achieving stable heating of the electric vehicle.

[0030] In any possible implementation of the first aspect, the thermal management control method further includes: at a seventh moment, controlling the compressor to operate at a second speed, the second speed being lower than the first speed.

[0031] The above possible implementation method, in the embodiment of the present application, when the actual heating value of the compressor is greater than the heating value of the passenger compartment, the rotation speed of the compressor is reduced to further reduce the actual heating value of the compressor, so that the actual heating value of the compressor can be adjusted to balance with the reduced heating value of the passenger compartment as soon as possible, which is beneficial to maintaining the triangular cycle of the compressor, thereby realizing stable heating of the electric vehicle.

[0032] In any possible implementation of the first aspect, the thermal management control method also includes: at an eighth moment after the seventh moment, the air outlet flow change of the air conditioner is less than a second air outlet flow threshold and the pressure change value of the first pressure sensor is less than the second pressure threshold, and the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening less than the second opening change value.

[0033] In the above possible implementation, the change in the air flow rate of the air conditioner is less than the second air flow rate threshold, indicating that the current air flow rate of the air conditioner has reached a stable state, and the pressure change value of the first pressure sensor is less than the second pressure threshold, indicating that the compressed refrigerant pressure output by the compressor has reached a stable state. In other words, after adjusting the valves and water pumps at the fifth, sixth and seventh moments, at the eighth moment, the actual heat generation of the compressor and the heat supply of the passenger compartment have reached a balanced state, and the triangular cycle of the compressor can be maintained stable without further significant adjustments to the valves in the refrigerant circuit.

[0034] In any possible implementation of the first aspect, the thermal management control method further includes: after the third moment and before the fifth moment, controlling the middle position of the air conditioner box damper of the air conditioner to face the condenser.

[0035] The above possible implementation method is, before adjusting the valve, the middle position of the air-conditioning box damper is turned toward the condenser, which can blow a large amount of heat in the condenser into the passenger compartment, thereby reducing the heat carried by the compressed refrigerant, so that the actual heating value of the compressor can be adjusted to balance with the heating value of the passenger compartment as soon as possible, which is beneficial to maintain the triangular cycle of the compressor, thereby realizing stable heating of the electric vehicle.

[0036] In a second aspect, an electric vehicle is provided, which uses the thermal management control method described in the first aspect or any possible implementation of the first aspect to adjust the temperature inside the vehicle.

[0037] It can be understood that the beneficial effects that can be achieved by the electric vehicle provided above can correspond to the beneficial effects of the electric vehicle thermal management control method provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the first structure of a thermal management system provided in an embodiment of the present application;

[0040] Figure 3 A second structural schematic diagram of a thermal management system provided in an embodiment of the present application;

[0041] Figure 4 A third structural schematic diagram of the thermal management system provided in an embodiment of the present application;

[0042] Figure 5 A fourth structural schematic diagram of a thermal management system provided in an embodiment of the present application;

[0043] Figure 6A fifth structural schematic diagram of a thermal management system provided in an embodiment of the present application;

[0044] Figure 7 A timing diagram of the valve opening in the refrigerant circuit provided in the embodiment of the present application;

[0045] Figure 8 A timing diagram of the water pump opening in the cooling circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The phrase "in one embodiment" in this application is used to indicate an example, illustration, or description. The solution described as "in one embodiment" in this application should not be interpreted as being more preferred or more advantageous than the solutions of other embodiments. Specifically, the use of "in one embodiment" is intended to present the inventive concept of this application in a specific way.

[0047] Figure 1 A schematic diagram of an electric vehicle provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 01 includes a thermal management system 10, a passenger compartment 20, a powertrain 30 and a power battery 40. The thermal management system 10 is used to perform heat management on the passenger compartment 20, the powertrain 30 and the power battery 40. For example, the thermal management system 10 can absorb heat from the passenger compartment 20, the powertrain 30 and the power battery 40, and the thermal management system 10 can also release heat to the passenger compartment 20, the powertrain 30 and the power battery 40. In addition, the thermal management system 10 can also absorb heat from the external environment or release heat to the external environment. Thus, through the transfer and control of heat, not only the powertrain 30 and the power battery 40 can work at a suitable temperature, but also a suitable temperature can be provided for the passenger compartment 20, thereby providing a comfortable driving environment for users.

[0048] In order to use the thermal management system 10 normally in a low temperature environment, PTC or heat pump is usually used in the related technology to provide heat. For example, when using PTC, the electrical energy is converted into thermal energy by PTC to heat the refrigerant in the thermal management system 10, so that heat is provided to the passenger compartment 20, the powertrain 30 or the power battery 40 through the flow of the refrigerant. For another example, when using a heat pump, the heat in the external environment is absorbed by the refrigerant, and the absorbed heat is transferred to the passenger compartment 20, the powertrain 30 or the power battery 40 by the heat pump, thereby driving the electric vehicle 01 to travel normally.

[0049] When using PTC as a heat source, on the one hand, due to the large size of PTC, it will occupy the limited space in the electric vehicle 01; on the other hand, since PTC needs to use electric energy to work, heating will accelerate the consumption of electric energy. For the electric vehicle 01 that uses electric energy as energy, it will cause the endurance time and mileage of the electric vehicle 01 to be reduced, affecting the user's driving experience. When using a heat pump for heating, it depends on whether the refrigerant can absorb heat from the external environment. When the external temperature is -20℃ or lower, the external environment has no heat to provide to the refrigerant, which will cause the heat pump to fail, thereby causing the thermal management system to fail.

[0050] In order to solve the above problems, the embodiments of the present application provide an electric vehicle thermal management control method and an electric vehicle. The thermal management control method provided in the embodiments of the present application is used to control the valve of the refrigerant circuit of the electric vehicle to realize the heating of the electric vehicle. For example, stable heating is achieved by maintaining the triangular cycle of the compressor. The triangular cycle refers to connecting the outlet and the inlet of the compressor, using the heat generated by the speed of the compressor as a heat source, and outputting compressed refrigerant through the compression processing of the refrigerant by the compressor. When the compressed refrigerant returns to the inlet of the compressor, the refrigerant temperature at the inlet of the compressor will be increased, thereby establishing a cycle of the three steps of suction, compression, and exhaust of the compressor to realize stable heating of the compressor. In this way, when the refrigerant in the refrigerant circuit cannot absorb heat from the outside (for example, the outside temperature is -20°C or lower), the thermal management system can be controlled to work normally without using PTC, thereby realizing stable heating of the electric vehicle 01.

[0051] The electric vehicle provided in the embodiment of the present application may be Figure 1 The electric vehicle 01 shown. The thermal management control method can be implemented by a control device of the thermal management system, which can be an independent integrated controller chip, or can be deployed in an air-conditioning controller or a vehicle controller of the electric vehicle, or can be deployed in a left body controller or a right body controller, which is not specifically limited in the embodiments of the present application.

[0052] For the electric vehicle 01, the heat supply Q1 of the passenger compartment and the actual heat generation Q2 of the compressor 101 satisfy the following formula: Q1 = A × Q2. Where A represents the coefficient of performance (COP). For example, when the outside temperature is -20°C, the range of A is 0.75 to 0.85.

[0053] In a possible implementation, the above Q1 is positively correlated with the air volume of the blower in the passenger compartment, the air outlet temperature of the air conditioning box, or the air inlet temperature of the air conditioning box. That is, when any one of the parameters of the blower air volume in the passenger compartment, the air outlet temperature of the air conditioning box, and the air inlet temperature of the air conditioning box increases, the heating amount Q1 of the passenger compartment also increases; when any one of the above parameters decreases, the heating amount Q1 of the passenger compartment also decreases.

[0054] In a possible implementation, the above Q2 is respectively positively correlated with the suction pressure, exhaust pressure or rotation speed of the compressor 101. That is, when any one of the suction pressure, exhaust pressure or rotation speed of the compressor 101 increases, the actual heating value Q2 of the compressor 101 also increases, and when any one of the above parameters decreases, the actual heating value Q2 of the compressor 101 also decreases.

[0055] When the heating value Q1 of the passenger compartment changes significantly, for example, the user operates the gear button of the hot air volume of the air conditioner to adjust the hot air volume of the passenger compartment to the maximum or minimum, the actual heating value Q2 of the compressor 101 cannot be quickly adjusted to the adapted heating value, which will cause the triangle cycle of the compressor 101 to be destroyed. When the heating value Q1 of the passenger compartment changes significantly, the thermal management control method provided in the embodiment of the present application can maintain the triangle cycle of the compressor 101 to a certain extent, so that the electric vehicle 01 can be stably heated.

[0056] To facilitate understanding of the thermal management control method provided in the embodiment of the present application, the technical solution in the embodiment of the present application is described below in conjunction with the accompanying drawings.

[0057] In one embodiment, the thermal management system 10 includes a refrigerant circuit. Figure 2 As shown, the refrigerant circuit includes a first valve 103, a second valve 104, a condenser 102, and a compressor 101. The compressor 101 is used to compress the refrigerant in the heating refrigerant circuit. The inlet of the second valve 104 is used to be connected to the outlet of the compressor 101 and control the flow rate of the compressed refrigerant output by the circulating compressor 101. The outlet of the second valve 104 is used to be connected to the inlet of the compressor 101. The inlet of the condenser 102 is used to be connected to the outlet of the compressor 101 through the first valve 103. The outlet of the condenser 102 is used to be connected to the inlet of the compressor 101. The first valve 103 is used to control the flow rate of the compressed refrigerant output by the circulating compressor 101. The condenser 102 is used to provide heating to the interior of the electric vehicle 01. The electric vehicle 01 is in a low temperature environment.

[0058] In the embodiment of the present application, the electric vehicle 01 being in a low-temperature environment means that the external environment temperature of the electric vehicle 01 is low, and the refrigerant in the refrigerant circuit cannot absorb heat from the environment to provide thermal energy to the refrigerant circuit.

[0059] In addition, the valve opening indicates the size of the opening of the valve. The larger the valve opening, the larger the opening of the valve, and accordingly, more medium passes through the valve; the smaller the valve opening, the smaller the opening of the valve, and the less medium passes through the valve. For example, the larger the opening of the first valve 103, the more refrigerant passes through the first valve 103.

[0060] The first valve 103 is used to connect between the inlet of the condenser 102 and the outlet of the compressor. If the opening of the first valve 103 increases, the flow rate of the compressed refrigerant output from the compressor 101 into the condenser 102 will increase. If the opening of the first valve 103 decreases, the flow rate of the compressed refrigerant output from the compressor 101 into the condenser 102 will decrease. When the first valve 103 is opened, the refrigerant flowing out of the outlet of the compressor 101 can flow into the condenser 102 through the first valve 103. The condenser 102 is used to condense the refrigerant passing through. When the refrigerant condenses in the condenser 102, the heat carried by the compressed refrigerant will be released. After the air conditioner starts to blow air, the heat in the condenser 102 will be blown into the passenger compartment, thereby achieving heating of the passenger compartment.

[0061] The inlet of the second valve 104 is used to connect to the outlet of the compressor 101 and control the flow rate of the compressed refrigerant output by the compressor 101, and the outlet of the second valve 104 is used to connect to the inlet of the compressor 101. If the opening of the second valve 104 increases, the flow rate of the compressed refrigerant output from the compressor 101 returning to the inlet of the compressor 101 will increase, and if the opening of the second valve 104 decreases, the flow rate of the compressed refrigerant output from the compressor 101 returning to the inlet of the compressor 101 will decrease.

[0062] In one embodiment, based on Figure 2 According to the structure shown, the thermal management control method provided in the embodiment of the present application includes: at a first moment, when the air conditioner of the electric vehicle 01 is adjusted to increase the hot air volume, the air conditioner starts to discharge air, controls the first valve 103 of the refrigerant circuit to reduce the opening to a first preset valve opening, and controls the second valve 104 of the refrigerant circuit to increase the opening to a second preset valve opening.

[0063] The increase in the hot air volume by the air conditioning of the electric vehicle 01 means that the current internal temperature of the electric vehicle 01 is higher than the external ambient temperature, but the hot air volume still needs to be increased to heat the passenger compartment, or it means that when the electric vehicle 01 is just started, the internal temperature is equal to the external ambient temperature, and the air conditioning is urgently needed to provide hot air to heat the passenger compartment. The increase in the hot air volume by the air conditioning of the electric vehicle 01 means that the current Q1 increases, and the actual heat generation Q2 of the compressor 101 cannot immediately match the increased Q1, that is, Q2 < Q1.

[0064] In addition, the first preset valve opening can be greater than the second preset valve opening, or less than or equal to the second preset valve opening, and the embodiment of the present application does not specifically limit this. The first preset valve opening is used to indicate that at a first moment, the opening of the first valve 103 is less than the opening before the first moment. Similarly, the second preset valve opening is used to indicate that at a first moment, the opening of the second valve 104 is greater than the opening before the first moment.

[0065] In a possible implementation, the magnitude relationship between the first preset valve opening and the second preset valve opening is related to the valve type of the corresponding valve. For example, when the first valve 103 and the second valve 104 are valves of different types, for example, the first valve 103 is an electrical expansion valve (EXV) and the second valve 104 is an electrical release valve (ERV), since the caliber of the EXV is inconsistent with the caliber of the ERV, there is no absolute magnitude relationship between the first preset valve opening and the second preset valve opening.

[0066] If the opening of the first valve 103 increases, more compressed refrigerant flow output by the compressor 101 will enter the condenser 102, while the compressed refrigerant flow flowing into the compressor 101 will decrease, which will cause the temperature of the refrigerant at the inlet of the compressor 101 to fail to increase quickly, ultimately destroying the triangular cycle of the compressor 101.

[0067] Based on this, when the air conditioning of the electric vehicle 01 increases the hot air volume at the first moment, the first valve 103 is controlled to reduce the opening, and the second valve 104 is controlled to increase the opening, so that the refrigerant output from the compressor 101 returns to the inlet of the compressor 101 faster, avoiding the rapid decrease of the refrigerant pressure at the inlet of the compressor 101 when the electric vehicle 01 increases the hot air volume, ensuring that the compressor 101 can stably supply heat, maintaining the stability of the triangle cycle to a certain extent, and improving the robustness of the triangle cycle. In this way, when the refrigerant in the refrigerant circuit cannot absorb heat from the outside (for example, the outside temperature is -20°C or lower), the thermal management system of the electric vehicle 01 can be controlled to work normally without additionally setting the PTC, thereby achieving stable heating of the electric vehicle 01.

[0068] In one embodiment, if Figure 3As shown, the refrigerant circuit also includes a first heat exchanger 105, a first inlet of the first heat exchanger 105 is used to be connected to the outlet of the compressor 101 through the second valve 104, a first outlet of the first heat exchanger 105 is used to be connected to the inlet of the compressor 101, a second inlet of the first heat exchanger 105 is used to be connected to the outlet of the first water pump 106 of the cooling circuit of the electric vehicle 01, a second outlet of the first heat exchanger 105 is used to be connected to an interface of a multi-way valve 107 of the cooling circuit of the electric vehicle 01, and the first heat exchanger 105 is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other.

[0069] Based on Figure 3 The structure shown, the thermal management control method provided in the embodiment of the present application also includes: at a first moment, controlling the opening of the first water pump 106 to be less than a first water pump opening threshold.

[0070] The first water pump opening degree threshold is used to indicate that the opening degree of the first water pump 106 decreases at the first moment.

[0071] In addition, the above-mentioned mutual heat exchange means that the heat carried in the refrigerant can be transferred to the coolant, so that the heat carried in the refrigerant passing through the first heat exchanger 105 will decrease, while the heat carried in the coolant passing through the first heat exchanger 105 will increase.

[0072] When the air conditioning of the electric vehicle 01 increases the hot air volume at the first moment, the opening of the first water pump 106 is controlled to be less than the first water pump opening threshold, and the coolant entering the first heat exchanger 105 is less, and the heat that can be exchanged with the refrigerant in the first heat exchanger 105 is limited. When the temperature of the coolant is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also limited, and the heat can still be retained more in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor 101, the refrigerant pressure and temperature at the inlet of the compressor 101 will also be increased, so that Q2 can adapt to the increased Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0073] It is understandable that the multi-way valve 107 can be a nine-way valve having nine different interfaces. The multi-way valve can also be other types of multi-way valves such as a six-way valve, a seven-way valve, and an eight-way valve. Compared with the nine-way valve, valves such as the six-way valve and the seven-way valve have fewer interfaces and are more cost-effective. If there are many branches in the cooling circuit that need to be connected, a nine-way valve or an eight-way valve with more interfaces can be selected. If there are few branches in the cooling circuit that need to be connected, a six-way valve or a seven-way valve with fewer interfaces can be selected. As an example and not a limitation, Figure 3Only two ports of the multi-way valve 107 are shown in the figure, the inlet of the first water pump 106 is used to be connected to the port 1 of the multi-way valve 107, and the second outlet of the first heat exchanger 105 is used to be connected to the port 2 of the multi-way valve 107.

[0074] In one embodiment, if Figure 4 As shown, the refrigerant circuit also includes an evaporator 108, a third valve 109, a fourth valve 110 and a first pressure sensor PT1. The outlet of the compressor 101 is used to be connected to the inlet of the first valve 103 and the inlet of the second valve 104 respectively through the first pressure sensor. The first pressure sensor PT1 is used to measure the pressure of the compressed refrigerant output by the compressor 101. The inlet of the evaporator 108 is used to be connected to the outlet of the condenser 102 and the first outlet of the first heat exchanger 105 respectively through the third valve 109 and to circulate the compressed refrigerant. The outlet of the evaporator 108 is used to be connected to the inlet of the compressor 101. The evaporator 108 is used to provide heating to the interior of the electric vehicle 01. The inlet of the fourth valve 110 is connected to the outlet of the condenser 102 and the first outlet of the first heat exchanger 105 respectively and to circulate the compressed refrigerant. The outlet of the fourth valve 110 is used to be connected to the inlet of the compressor 101. The third valve 109 and the fourth valve 110 are used to control the flow rate of the compressed refrigerant.

[0075] The outlet of the third valve 109 is used to be connected to the inlet of the evaporator 108, and the inlet of the third valve 109 is used to be connected to the outlet of the condenser 102 and the first outlet of the first heat exchanger 105. The third valve 109 is used to control the flow rate of the compressed refrigerant. If the opening of the third valve 109 increases, the flow rate of the compressed refrigerant entering the evaporator 108 will increase, and if the opening of the third valve 109 decreases, the flow rate of the compressed refrigerant entering the evaporator 108 will decrease. When the third valve 109 is opened, the compressed refrigerant can flow into the evaporator 108 through the third valve 109, and the evaporator 108 is used to evaporate the refrigerant passing through.

[0076] The outlet of the fourth valve 110 is used to be connected to the inlet of the compressor 101, and the inlet of the fourth valve 110 is used to be connected to the outlet of the condenser 102 and the first outlet of the first heat exchanger 105. The fourth valve 110 is used to control the flow rate of the compressed refrigerant. If the opening of the fourth valve 110 increases, the flow rate of the compressed refrigerant output from the condenser 102 and the first heat exchanger 105 back to the inlet of the compressor 101 will increase, and if the opening of the fourth valve 110 decreases, the flow rate of the compressed refrigerant output from the condenser 102 and the first heat exchanger 105 back to the inlet of the compressor 101 will decrease.

[0077] Based on Figure 4According to the structure shown, the thermal management control method provided in the embodiment of the present application also includes: at a second moment after the first moment, the air outlet flow rate change of the air conditioner is greater than or equal to the first air outlet flow rate threshold and the pressure change value of the first pressure sensor PT1 is greater than or equal to the first pressure threshold, the opening of the third valve 109 is controlled to be reduced to the third preset valve opening, and the opening of the fourth valve 110 is controlled to be increased to the fourth preset valve opening.

[0078] The change in the air flow rate of the air conditioner is greater than or equal to the first air flow rate threshold, indicating that the air flow rate of the air conditioner is unstable, and the change in the pressure of the first pressure sensor PT1 is greater than or equal to the first pressure threshold, indicating that the pressure of the compressed refrigerant output by the compressor 101 is unstable. That is to say, after adjusting the valves and the water pump at the first moment, the valves in the refrigerant circuit and the water pump in the cooling circuit need to be adjusted at the second moment.

[0079] Furthermore, the third preset valve opening is used to indicate that at the second moment, the opening of the third valve 109 is smaller than that at the first moment. Similarly, the fourth preset valve opening is used to indicate that at the second moment, the opening of the fourth valve 110 is larger than that at the first moment.

[0080] Based on the above technical solution, at the second moment, the opening of the third valve 109 is controlled to decrease, which can reduce the flow of compressed refrigerant passing through the evaporator 108, and the opening of the fourth valve 110 is controlled to increase, which can increase the flow of compressed refrigerant returning to the inlet of the compressor 101, thereby increasing the refrigerant pressure and temperature at the inlet of the compressor 101, so that Q2 can adapt to the increased Q1 as soon as possible, which is beneficial to maintaining the stability of the triangular cycle of the compressor 101, improving the robustness of the triangular cycle of the compressor 101, and enabling the electric vehicle 01 to provide stable heating.

[0081] In one embodiment, if Figure 4 As shown, the refrigerant circuit also includes a second heat exchanger 111, a first inlet of the second heat exchanger 111 is used to connect to the outlet of the fourth valve 110, a first outlet of the second heat exchanger 111 is used to connect to the inlet of the compressor 101, a second inlet of the second heat exchanger 111 is used to connect to the outlet of the second water pump 112 of the cooling circuit of the electric vehicle 01, a second outlet of the second heat exchanger 111 is used to connect to another interface of the multi-way valve 107, and the second heat exchanger 111 is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other.

[0082] The thermal management control method further includes: at the second moment, controlling the opening degree of the second water pump 112 to be less than a second water pump opening degree threshold.

[0083] The second water pump opening degree threshold is used to indicate that the opening degree of the second water pump 112 decreases at the second moment.

[0084] At the second moment, the opening of the second water pump 112 is controlled to be less than the second water pump opening threshold, and the coolant entering the second heat exchanger 111 is less, and the heat that can be exchanged with the refrigerant in the second heat exchanger 111 is limited. When the temperature of the coolant is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also limited, and the heat can still be retained more in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor 101, the refrigerant pressure and temperature at the inlet of the compressor 101 will also be increased, so that Q2 can adapt to the increased Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0085] By way of example and not limitation, Figure 4 Only four ports of the multi-way valve 107 are shown. The inlet of the first water pump 106 is used to connect to port 1 of the multi-way valve 107, the second outlet of the first heat exchanger 105 is used to connect to port 2 of the multi-way valve 107, the second outlet of the second heat exchanger 111 is used to connect to port 3 of the multi-way valve 107, and the inlet of the second water pump 112 is used to connect to port 4 of the multi-way valve 107.

[0086] In one embodiment, the thermal management control method also includes: at a third moment after the second moment, the air outlet flow rate change of the air conditioner is less than the first air outlet flow rate threshold and the pressure change value of the first pressure sensor PT1 is less than the first pressure threshold, and the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 are controlled to keep the valve opening change less than the first opening change value.

[0087] Among them, the change of the air flow rate of the air conditioner is less than the first air flow rate threshold, which means that the current air flow rate of the air conditioner has reached a stable state, and the pressure change value of the first pressure sensor PT1 is less than the first pressure threshold, which means that the pressure of the compressed refrigerant output by the compressor 101 has reached a stable state. In other words, after adjusting the valve and the water pump at the first moment and the second moment, Q2 and Q1 have reached a balanced state at the third moment.

[0088] In addition, the valve opening change less than the first opening change value indicates that the valve opening change is small or no change. That is, after Q2 and Q1 reach a balanced state, the triangular cycle of the compressor 101 can be maintained stable without making significant adjustments to the valves in the refrigerant circuit.

[0089] In one embodiment, if Figure 5 As shown, the refrigerant circuit further includes a fifth valve 113 , which is used to be connected between the inlet and the outlet of the compressor 101 , and the fifth valve 113 is used to control the compressed refrigerant flowing from the outlet to the inlet of the compressor 101 .

[0090] The thermal management control method also includes: at the fourth moment before the first moment, the air-conditioning switch of the electric vehicle 01 increases the change value of the hot air volume by more than the first air volume change threshold, and controls the compressor 101 to start and operate at the first speed; controls the opening of the fifth valve 113 to increase to the fifth preset valve opening, controls the opening of the first valve 103 to increase to the sixth preset valve opening, the fifth preset valve opening is greater than the sixth preset valve opening, and the sixth preset valve opening is greater than the first valve preset opening.

[0091] The fourth moment T4 is the moment when the change value of the air conditioning switch to increase the hot air volume is greater than the first air volume change threshold, that is, the moment when the heating function of the electric vehicle 01 is started and the delta cycle is established. In a possible implementation method, by receiving parameters such as the outside temperature, the actual temperature of the passenger compartment, the set temperature of the passenger compartment, the body temperature of the drive motor, and the temperature of the power battery 40, it is determined whether there is a heating demand at present. If the outside temperature is lower than the critical temperature when the refrigerant absorbs heat (for example, the outside temperature is -20°C), or the actual temperature of the passenger compartment is lower than the set temperature of the passenger compartment, or the body temperature of the drive motor and the temperature of the power battery 40 are both lower than the temperature required for normal operation, it indicates that there is a need to establish a delta cycle of the compressor 101. If the outside temperature is higher than the critical temperature when the refrigerant absorbs heat, or the actual temperature of the passenger compartment is not lower than the set temperature of the passenger compartment, or the body temperature of the drive motor and the temperature of the power battery 40 are not lower than the temperature required for normal operation, it indicates that there is no need to establish a delta cycle of the compressor 101.

[0092] The first speed is a preset speed threshold, or the first speed is the maximum speed value allowed by the compressor 101. For example, when the first speed is the preset speed threshold, after the compressor 101 is started, the speed of the compressor 101 is controlled to be greater than the first speed; when the first speed is the maximum speed value allowed by the compressor 101, after the compressor 101 is started, the speed of the compressor 101 is controlled to be equal to the first speed, that is, the first speed is the maximum speed of the compressor 101. In this way, controlling the compressor 101 to work at the highest speed can improve the heating efficiency of the compressor 101 and shorten the establishment process of the compressor triangle cycle to a certain extent.

[0093] In addition, the opening of the fifth valve 113 is greater than the fifth preset valve opening, indicating that the fifth valve 113 is open and allows at least part of the refrigerant at the outlet of the compressor 101 to return to the inlet of the compressor 101. The opening of the first valve 103 increases to the sixth preset valve opening, indicating that the first valve 103 is open and allows at least part of the refrigerant at the outlet of the compressor 101 to flow into the condenser 102. The fifth preset valve opening is greater than the sixth preset valve opening, indicating that both the fifth valve 113 and the first valve 103 are open, and most of the compressed refrigerant at the outlet of the compressor 101 returns to the inlet of the compressor 101. The sixth preset valve opening is greater than the first valve preset opening, indicating that at the fourth moment before the first moment, the opening of the first valve 103 is larger, and at the first moment after the fourth moment, the opening of the first valve 103 is smaller.

[0094] After starting the compressor 101, the compressor 101 is controlled to operate at the first speed, and the fifth valve 113 is opened so that the refrigerant output from the compressor 101 re-enters the compressor 101 through the fifth valve 113. Since the refrigerant output from the compressor 101 is a compressed refrigerant after being compressed by the compressor 101, the pressure and temperature of the compressed refrigerant are higher than the pressure and temperature of the refrigerant at the inlet of the compressor 101. Therefore, when the compressed refrigerant flows to the inlet of the compressor 101 through the fifth valve 113, the pressure and temperature of the refrigerant at the inlet of the compressor 101 can be increased, so that the compressor 101 can work normally. Opening the first valve 103 can transfer the compressed refrigerant output from the compressor 101 to the condenser 102, thereby transferring heat to the passenger compartment through the condenser 102.

[0095] In one embodiment, if Figure 6 As shown, the refrigerant circuit also includes an air conditioning box damper 114 , which is disposed on the same side of the condenser 102 and the evaporator 108 , and is used to guide the air blowing toward the condenser 102 and the evaporator 108 .

[0096] The thermal management control method further includes: between the first moment after the fourth moment, controlling the air conditioner box damper 114 of the air conditioner to face the evaporator 108 at a middle position.

[0097] If the air conditioner damper 114 is facing the condenser 102, the heat in the condenser 102 will be blown into the passenger compartment, thereby reducing the heat carried in the compressed refrigerant, and then reducing the pressure and temperature of the compressed refrigerant returning to the inlet of the compressor 101. The low refrigerant pressure and temperature at the inlet of the compressor 101 will further cause Q2 to decrease. In the case of Q2<Q1, the balance between Q2 and Q1 will be further disrupted. Therefore, turning the middle position of the air conditioner damper 114 toward the evaporator 108 can avoid blowing a large amount of heat in the condenser 102 into the passenger compartment, thereby avoiding excessive reduction of the heat carried in the compressed refrigerant, and avoiding further reduction of Q2, so that Q2 can be adjusted to balance with Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0098] In one embodiment, if Figure 6 As shown, the refrigerant circuit further includes a gas-liquid separator 115, which is connected between the inlet of the compressor 101 and the fifth valve 113. The gas-liquid separator 115 can separate the gas-liquid mixture into gas and liquid, so as to leave the liquid in the gas-liquid mixture and output the gas to the compressor 101, thereby improving the compression effect of the compressor 101.

[0099] In one embodiment, if Figure 6 As shown, the refrigerant circuit also includes a sixth valve 116 , which is connected between the outlet of the condenser 102 and the inlet of the compressor 101 . The sixth valve 116 can be used to control the flow rate of compressed refrigerant input into the compressor 101 .

[0100] In one embodiment, if Figure 6 As shown, the refrigerant circuit further includes a plurality of check valves, such as a first check valve CV1, a second check valve CV2, and a third check valve CV3, and the check valves are used to prevent the medium from flowing back. The first check valve CV1 is arranged between the first outlet of the first heat exchanger 105 and the outlet of the condenser 102, and is used to prevent the refrigerant flowing out of the condenser 102 from flowing back into the first outlet of the first heat exchanger 105. The second check valve CV2 is arranged between the outlet of the evaporator 108 and the inlet of the compressor 101, and is used to prevent the refrigerant flowing to the inlet of the compressor 101 from flowing back into the evaporator 108. The third check valve CV3 is arranged between the first outlet of the second heat exchanger 111 and the inlet of the compressor 101, and is used to prevent the refrigerant flowing to the inlet of the compressor 101 from flowing back into the second heat exchanger 111.

[0101] In one embodiment, if Figure 6As shown, a plurality of pressure and temperature sensors are also provided in the refrigerant circuit. For example, a second pressure and temperature sensor PT2 and a third pressure and temperature sensor PT3 are also provided in the refrigerant circuit. The second pressure and temperature sensor PT2 is provided at the inlet of the compressor 101 or the inlet of the gas-liquid separator 115, and the third pressure and temperature sensor PT3 is provided at the outlet of the condenser 102. The second pressure and temperature sensor PT2 and the third pressure and temperature sensor PT3 can assist in measuring the pressure change of the compressor 101 when the first pressure and temperature sensor PT1 fails, and can also be used to provide parameters such as the suction pressure and temperature of the compressor, the exhaust pressure and temperature of the condenser, so as to accurately calculate the heating capacity Q1 of the passenger compartment and the actual heating capacity Q2 of the compressor 101.

[0102] In one embodiment, if Figure 6 As shown, the cooling circuit also includes multiple temperature sensors. For example, a first temperature sensor NTC1 and a second temperature sensor NTC2. The first temperature sensor NTC1 is arranged between the coolant inlet of the power assembly 30 and the outlet of the first water pump 106, and is used to measure the water inlet temperature of the drive motor; the second temperature sensor NTC2 is arranged between the coolant inlet of the power battery 40 and the port 6 of the multi-way valve 107, and is used to measure the water inlet temperature of the power battery 40.

[0103] In one embodiment, if Figure 6 As shown, the third valve 109, the fourth valve 110 and the fifth valve 113 may all be EXVs, and the first valve 103, the second valve 104 and the sixth valve 116 may all be ERVs. The types of the above valves are only used for examples. In practical applications, the above valves may all be EXVs or ERVs or other types of valves, which are not specifically limited in the embodiments of the present application.

[0104] Reference Figure 6 It can be known that the refrigerant flowing out of the outlet of the compressor 101 can directly flow back to the inlet of the compressor 101 through the fifth valve 113, and can also flow to the inlet of the condenser 102 or the refrigerant inlet of the first heat exchanger 105 respectively; the refrigerant flowing out of the outlet of the condenser 102 can flow back to the inlet of the compressor 101 through the evaporator 108, the refrigerant flow channel of the second heat exchanger 111, or the sixth valve 116 respectively; the refrigerant flowing out of the refrigerant outlet of the first heat exchanger 105 can flow back to the inlet of the compressor 101 through the evaporator 108, the refrigerant flow channel of the second heat exchanger 111, or the sixth valve 116 respectively. In other words, the refrigerant flowing out of the outlet of the compressor 101 can flow back to the inlet of the compressor 101 through the above-mentioned multiple paths, thereby realizing the refrigerant circulation in the refrigerant circuit.

[0105] In addition, 1 to 7 in the multi-way valve 107 represent seven ports of the multi-way valve 107. By controlling the gear position of the multi-way valve 107, the connection conditions of the seven ports in the multi-way valve 107 can be controlled. The seven ports are respectively connected to the first water pump 106, the second water pump 112, the first heat exchanger 105, the second heat exchanger 111, the coolant flow channel of the power assembly 30, and the coolant flow channel of the power battery 40, so that by controlling the connection conditions of the seven ports of the multi-way valve 107, heat exchange with the refrigerant in the first heat exchanger 105 or the refrigerant in the second heat exchanger 111, and thermal management of the power assembly 30 or the power battery 40 are achieved. For example, when the temperature of the coolant flowing through the power assembly 30 is higher than the body temperature of the drive motor in the power assembly 30, the coolant heats the power assembly 30, and if the temperature of the coolant is lower than the body temperature of the drive motor in the power assembly 30, the coolant cools the power assembly 30.

[0106] The following Figure 6 Taking the structure shown as an example, the thermal management control method provided by the embodiment of the present application when Q1<Q2 is described in detail.

[0107] At the fifth moment after the third moment, the change value of the air conditioning switch reducing the hot air volume is greater than the second air volume change threshold. The thermal management control method provided in the embodiment of the present application also includes: controlling the opening of the third valve 109 to increase to the seventh preset valve opening, and controlling the opening of the fourth valve 110 to decrease to the eighth preset valve opening.

[0108] The change value of the air conditioning switch reducing the hot air volume is greater than the second air volume change threshold, indicating that the air conditioning switch is operated to reduce the hot air volume to a great extent at this time.

[0109] In the embodiment of the present application, when Q1>Q2, the opening of the third valve 109 is first controlled to increase and the opening of the fourth valve 110 is controlled to decrease, so that more of the refrigerant output from the compressor 101 enters the evaporator 108 rather than the second heat exchanger 111. Because the outside temperature is extremely low, the amount of heat that the refrigerant can absorb when evaporating in the evaporator 108 is also limited. In this way, the refrigerant transferred to the inlet of the compressor 101 will not cause large refrigerant pressure and fluctuations at the inlet of the compressor 101, thereby maintaining the stability of the triangular cycle to a certain extent and improving the robustness of the triangular cycle.

[0110] Based on the above technical solution, when the heating demand decreases, the suction pressure of the compressor 101 can be adjusted by controlling the opening of the third valve 109 and the fourth valve 110, thereby maintaining the stability of the triangular cycle of the compressor 101 and avoiding the destruction of the triangular cycle, so that the electric vehicle 01 can still provide stably heated.

[0111] At a sixth moment after the fifth moment, the air outlet flow rate change of the air conditioner is greater than or equal to the second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold. The thermal management control method also includes: controlling the opening of the first valve 103 to increase to a ninth preset valve opening, and controlling the opening of the second valve 104 to decrease to a tenth preset valve opening.

[0112] Among them, the air outlet flow change of the above-mentioned air conditioner is greater than or equal to the second air outlet flow threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, indicating that at the sixth moment, after the opening of the third valve 109 and the opening of the fourth valve 110 are controlled, Q1 and Q2 still do not meet the equilibrium state, and the valve opening in the refrigerant circuit needs to continue to be adjusted.

[0113] If the second valve 104 is controlled to open wider, the refrigerant output from the compressor 101 will pass more through the first heat exchanger 105 rather than the condenser 102, and more heat will remain in the refrigerant flow channel of the compressor 101. If the speed of the compressor 101 remains unchanged, the compressor 101 will overheat and overpressure, thereby causing danger.

[0114] In the embodiment of the present application, when Q1>Q2, the opening of the first valve 103 is controlled to be greater than the opening of the second valve 104, so that more of the refrigerant output from the compressor 101 enters the condenser 102 rather than the first heat exchanger 105, and the blower blows the heat in the condenser 102 to the passenger compartment, so that more of the heat carried in the compressed refrigerant is blown into the passenger compartment, thereby reducing the refrigerant pressure and temperature at the inlet of the compressor 101, maintaining the stability of the triangular cycle to a certain extent, and improving the robustness of the triangular cycle.

[0115] At the seventh moment after the sixth moment, the air outlet flow change of the air conditioner is greater than or equal to the second air outlet flow threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold. The thermal management control method also includes: controlling the opening of the second water pump 112 to be greater than the third water pump opening threshold.

[0116] The fact that the opening degree of the second water pump 112 is greater than the third water pump opening degree threshold value indicates that the opening degree of the second water pump 112 is increased.

[0117] At the seventh moment, the opening of the second water pump 112 is controlled to be greater than the third water pump opening threshold, the amount of coolant entering the second heat exchanger 111 increases, and the amount of heat that can be exchanged with the refrigerant in the second heat exchanger 111 increases. When the temperature of the coolant is lower than the temperature of the refrigerant, more heat is exchanged out of the refrigerant, and the amount of heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor 101, the refrigerant pressure and temperature at the inlet of the compressor 101 will not increase significantly, so that Q2 can adapt to the reduced Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0118] At the seventh moment, the thermal management control method further includes: controlling the opening degree of the first water pump 106 to be greater than a fourth water pump opening degree threshold.

[0119] The fact that the opening degree of the first water pump 106 is greater than the fourth water pump opening degree threshold indicates that the opening degree of the first water pump 106 is increased.

[0120] At the seventh moment, the opening of the first water pump 106 is greater than the fourth water pump opening threshold, the amount of coolant entering the first heat exchanger 105 increases, and the amount of heat that can be exchanged with the refrigerant in the first heat exchanger 105 increases. When the temperature of the coolant is lower than the temperature of the refrigerant, more heat is exchanged out of the refrigerant, and the amount of heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor 101, the refrigerant pressure and temperature at the inlet of the compressor 101 will not increase significantly, so that Q2 can adapt to the reduced Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0121] At the seventh moment, the thermal management control method further includes: controlling the compressor 101 to operate at a second speed, where the second speed is lower than the first speed.

[0122] It can be seen from the above content that the actual heat generation Q2 of the compressor 101 is related to the rotation speed of the compressor. The greater the rotation speed of the compressor, the greater Q2. Conversely, the smaller the rotation speed, the smaller Q2.

[0123] In the embodiment of the present application, when Q1<Q2, the rotation speed of the compressor 101 is reduced to further reduce the actual heat generation Q2 of the compressor 101, so that Q2 can be adjusted to balance with the reduced Q1 as soon as possible, which is beneficial to maintaining the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0124] At the eighth moment after the seventh moment, the air outlet flow change of the air conditioner is less than the second air outlet flow threshold and the pressure change value of the first pressure sensor is less than the second pressure threshold, and the thermal management control method also includes: controlling the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 to keep the valve opening less than the second opening change value.

[0125] Among them, the change of the air flow rate of the air conditioner is less than the second air flow rate threshold value, which indicates that the current air flow rate of the air conditioner has reached a stable state, and the pressure change value of the first pressure sensor PT1 is less than the second pressure threshold value, which indicates that the pressure of the compressed refrigerant output by the compressor 101 has reached a stable state. In other words, after adjusting the valve and the water pump at the fifth moment, the sixth moment and the seventh moment, Q2 and Q1 have reached a balanced state at the eighth moment.

[0126] In addition, the valve opening change less than the second opening change value indicates that the valve opening change is small or no change. That is, after Q2 and Q1 reach a balanced state, the triangular cycle of the compressor 101 can be maintained stable without making significant adjustments to the valves in the refrigerant circuit.

[0127] The thermal management control method further includes: after the third moment and before the fifth moment, controlling the middle position of the air conditioner box damper 114 of the air conditioner to face the condenser 102.

[0128] If the middle position of the air conditioner damper 114 is facing the evaporator 108, the refrigerant will absorb heat when evaporating in the evaporator 108, which will further increase the suction pressure and exhaust pressure of the compressor 101, and the heat in the condenser 102 cannot be discharged, resulting in the outlet pressure of the condenser 102 cannot be reduced, which will further cause Q2 to increase, and Q2 and Q1 cannot maintain balance. Therefore, by turning the middle position of the air conditioner damper 114 toward the condenser 102, a large amount of heat in the condenser 102 can be blown into the passenger compartment, thereby reducing the heat carried by the compressed refrigerant, so that Q2 can be adjusted to balance with Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101, thereby achieving stable heating of the electric vehicle 01.

[0129] The following combination Figure 7 and Figure 8 , describes in detail the change process of the valve opening in the refrigerant circuit and the water pump opening in the cooling circuit after the air conditioner switch increases or decreases the hot air volume. Figure 7 and Figure 8 The broken lines shown in the figure only indicate the changing trends of the valve opening and the water pump opening, and do not indicate the specific numerical correspondence.

[0130] At the fourth moment T4, the change value of the air conditioning switch increasing the hot air volume is greater than the first air volume change threshold. At this time, the user starts the heating function of the electric vehicle 01, and the compressor 101 starts to establish a triangular cycle. The opening of the fifth valve 113 increases to the fifth preset valve opening, and the opening of the first valve 103 increases to the sixth preset valve opening.

[0131] At the first moment T1, the air conditioner of the electric vehicle 01 starts to blow air when the air volume of hot air is increased, the first valve 103 is controlled to reduce the opening to the first preset valve opening, and the second valve 104 is controlled to increase the opening to the second preset valve opening.

[0132] At the second moment T2, the air outlet flow rate change of the air conditioner is greater than or equal to the first air outlet flow rate threshold and the pressure change value of the first pressure sensor PT1 is greater than or equal to the first pressure threshold, the opening of the third valve 109 is controlled to be reduced to the third preset valve opening, and the opening of the fourth valve 110 is controlled to be increased to the fourth preset valve opening.

[0133] At the third moment T3, the air flow rate change of the air conditioner is less than the first air flow rate threshold and the pressure change value of the first pressure sensor PT1 is less than the first pressure threshold, indicating that Q2 and Q1 have reached a balance state. At this time, there is no need to make major adjustments to the valves in the refrigerant circuit, that is, to control the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 to control the valve opening change to be less than the first opening change value.

[0134] After Q1 and Q2 reach a balanced state, when the change value of the air volume reduced by the air conditioner switch is greater than the second air volume change threshold, it means that Q1>Q2 at present.

[0135] At the fifth moment T5, the change value of the air conditioning switch to reduce the hot air volume is greater than the second air volume change threshold, the third valve 109 is controlled to increase its opening to the seventh preset valve opening, and the fourth valve 110 is controlled to decrease its opening to the eighth preset valve opening.

[0136] At the sixth moment T6, the air outlet flow rate change of the air conditioner is greater than or equal to the second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, the opening of the first valve 103 is controlled to increase to the ninth preset valve opening, and the opening of the second valve 104 is controlled to decrease to the tenth preset valve opening.

[0137] At the seventh moment T7, the air outlet flow rate change of the air conditioner is greater than or equal to the second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, the opening of the second water pump 112 is controlled to be greater than the third water pump opening threshold, and the opening of the first water pump 106 is controlled to be greater than the fourth water pump opening threshold.

[0138] At the eighth moment T8, the air flow rate change of the air conditioner is less than the second air flow rate threshold and the pressure change value of the first pressure sensor is less than the second pressure threshold, indicating that Q2 and Q1 have reached a balance state. At this time, there is no need to make major adjustments to the valves in the refrigerant circuit, that is, to control the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 to control the valve opening change to be less than the second opening change value.

[0139] In one embodiment, an electric vehicle 01 is provided, and the electric vehicle 01 uses the thermal management control method provided in the above embodiment to adjust the temperature inside the vehicle.

[0140] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A thermal management control method for an electric vehicle, characterized in that: The thermal management control method is used to control the valve of the refrigerant circuit of the electric vehicle to realize heating of the electric vehicle. The refrigerant circuit includes a first valve, a second valve, a condenser, and a compressor. The compressor is used to compress and heat the refrigerant in the refrigerant circuit. The inlet of the second valve is used to connect to the outlet of the compressor and control the flow of compressed refrigerant output by the compressor. The outlet of the second valve is used to connect to the inlet of the compressor. The inlet of the condenser is used to connect to the outlet of the compressor through the first valve. The outlet of the condenser is used to connect to the inlet of the compressor. The first valve is used to control the flow of compressed refrigerant output by the compressor. The condenser is used to heat the interior of the electric vehicle. The electric vehicle is in a low temperature environment. The thermal management control method includes: At the first moment, when the air conditioner of the electric vehicle is adjusted to increase the hot air volume, the air conditioner starts to blow air, controls the first valve of the refrigerant circuit to reduce the opening to the first preset valve opening, and controls the second valve of the refrigerant circuit to increase the opening to the second preset valve opening.

2. The thermal management control method according to claim 1, characterized in that: The refrigerant circuit includes a first heat exchanger, a first inlet of the first heat exchanger is used to be connected to the outlet of the compressor through the second valve, a first outlet of the first heat exchanger is used to be connected to the inlet of the compressor, a second inlet of the first heat exchanger is used to be connected to the outlet of the first water pump of the electric vehicle cooling circuit, and a second outlet of the first heat exchanger is used to be connected to an interface of the multi-way valve of the electric vehicle cooling circuit. The first heat exchanger is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other. The thermal management control method also includes: At the first moment, the opening degree of the first water pump is controlled to be smaller than a first water pump opening degree threshold.

3. The thermal management control method according to claim 1 or 2, characterized in that: The refrigerant circuit also includes an evaporator, a third valve, a fourth valve and a first pressure sensor. The outlet of the compressor is used to be connected to the inlet of the first valve and the inlet of the second valve respectively through the first pressure sensor. The first pressure sensor is used to measure the pressure of the compressed refrigerant output by the compressor. The inlet of the evaporator is used to be connected to the outlet of the condenser and the first outlet of the first heat exchanger respectively through the third valve and the compressed refrigerant flows. The outlet of the evaporator is used to be connected to the inlet of the compressor. The evaporator is used to heat the interior of the electric vehicle. The inlet of the fourth valve is connected to the outlet of the condenser and the first outlet of the first heat exchanger respectively and the compressed refrigerant flows. The outlet of the fourth valve is used to be connected to the inlet of the compressor. The third valve and the fourth valve are used to control the flow rate of the compressed refrigerant. The thermal management control method also includes: At a second moment after the first moment, the air outlet flow rate change of the air conditioner is greater than or equal to the first air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the first pressure threshold, the third valve opening is controlled to be reduced to the third preset valve opening, and the fourth valve opening is controlled to be increased to the fourth preset valve opening.

4. The thermal management control method according to claim 3, characterized in that: The refrigerant circuit further includes a second heat exchanger, wherein a first inlet of the second heat exchanger is used to be connected to an outlet of the fourth valve, a first outlet of the second heat exchanger is used to be connected to an inlet of the compressor, a second inlet of the second heat exchanger is used to be connected to an outlet of a second water pump of the electric vehicle cooling circuit, and a second outlet of the second heat exchanger is used to be connected to another interface of the multi-way valve, and the second heat exchanger is used to circulate the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchange heat with each other, and the thermal management control method further includes: At the second moment, the opening degree of the second water pump is controlled to be smaller than a second water pump opening degree threshold.

5. The thermal management control method according to claim 3 or 4, characterized in that: The thermal management control method further comprises: At a third moment after the second moment, the air outlet flow change of the air conditioner is less than the first air outlet flow threshold and the pressure change value of the first pressure sensor is less than the first pressure threshold, and the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening change less than the first opening change value.

6. The thermal management control method according to any one of claims 1 to 5, characterized in that: The refrigerant circuit further includes a fifth valve, the fifth valve being used to be connected between the inlet and the outlet of the compressor, the fifth valve being used to control the compressed refrigerant flowing from the outlet to the inlet of the compressor, and the thermal management control method further includes: At a fourth moment before the first moment, the change value of the hot air volume increased by the air conditioner switch of the electric vehicle is greater than the first air volume change threshold, and the compressor is controlled to start and operate at a first speed; The fifth valve opening is controlled to increase to a fifth preset valve opening, and the first valve opening is controlled to increase to a sixth preset valve opening, wherein the fifth preset valve opening is greater than the sixth preset valve opening, and the sixth preset valve opening is greater than the first preset valve opening.

7. The thermal management control method according to claim 6, characterized in that: The refrigerant circuit further includes an air conditioner damper, the air conditioner damper is disposed on the same side of the condenser and the evaporator, the air conditioner damper is used to guide the air blowing toward the condenser and the evaporator, and the thermal management control method further includes: After the fourth moment and before the first moment, the middle position of the air conditioner box damper of the air conditioner is controlled to face the evaporator.

8. The thermal management control method according to claim 5, characterized in that: The thermal management control method further comprises: At the fifth moment after the third moment, the change value of the air conditioning switch reducing the hot air volume is greater than the second air volume change threshold, and the third valve opening is controlled to increase to the seventh preset valve opening, and the fourth valve opening is controlled to decrease to the eighth preset valve opening.

9. The thermal management control method according to claim 8, characterized in that: The thermal management control method further comprises: At the sixth moment after the fifth moment, the air outlet flow rate change of the air conditioner is greater than or equal to the second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, and the first valve opening is controlled to increase to the ninth preset valve opening, and the second valve opening is controlled to decrease to the tenth preset valve opening.

10. The thermal management control method according to claim 9, characterized in that: The thermal management control method further comprises: At the seventh moment after the sixth moment, the air outlet flow rate change of the air conditioner is greater than or equal to the second air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to the second pressure threshold, and the opening of the second water pump is controlled to be greater than the third water pump opening threshold.

11. The thermal management control method according to claim 10, characterized in that: The thermal management control method further comprises: At the seventh moment, the opening degree of the first water pump is controlled to be greater than a fourth water pump opening degree threshold.

12. The thermal management control method according to claim 10 or 11, characterized in that: The thermal management control method further comprises: At the seventh moment, the compressor is controlled to operate at a second speed, which is lower than the first speed.

13. The thermal management control method according to any one of claims 10 to 12, characterized in that: The thermal management control method further comprises: At an eighth moment after the seventh moment, the air outlet flow change of the air conditioner is less than the second air outlet flow threshold and the pressure change value of the first pressure sensor is less than the second pressure threshold, and the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening less than the second opening change value.

14. The thermal management control method according to any one of claims 10 to 13, characterized in that: The thermal management control method further comprises: After the third moment and before the fifth moment, the middle position of the air conditioner box damper of the air conditioner is controlled to face the condenser.

15. An electric vehicle, characterized in that: The electric vehicle uses the thermal management control method as described in any one of claims 1-14 to adjust the temperature inside the vehicle.

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