An electric vehicle thermal management control method and electric vehicle

Abstract

The application provides an electric vehicle heat management control method and an electric vehicle, and relates to the technical field of energy sources. The heat management control method is used for controlling a valve of a refrigerant circuit of an electric vehicle to realize heating of the electric vehicle. An inlet of a second valve is used for connecting an outlet of a compressor and controlling a flow of compressed refrigerant output by the compressor. An outlet of the second valve is used for connecting an inlet of the compressor. An inlet of a condenser is used for connecting the outlet of the compressor through a first valve. The electric vehicle is in a low-temperature environment. The heat management control method comprises the following steps: in the case that air conditioning of the electric vehicle is adjusted to increase a hot air volume at a first time, the air conditioning starts to blow air, the first valve of the refrigerant circuit is controlled to reduce an opening degree to a first preset valve opening degree, and the second valve of the refrigerant circuit is controlled to increase the opening degree to a second preset valve opening degree. In this way, when the external temperature is lower than a critical temperature at which the refrigerant absorbs heat, the electric heater does not need to be used, and the heat management system can be controlled to realize rapid and stable heating of a passenger cabin of the electric vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy, and particularly relates to a thermal management control method of an electric vehicle and the electric vehicle. BACKGROUND

[0002] The thermal management system of the electric vehicle is an important component of the electric vehicle, and is used for adjusting the temperature of the power battery, power assembly and passenger cabin of the electric vehicle. In the related art, in the case that the outside temperature is low, an electric heater (positive temperature coefficient, PTC) or a heat pump is usually used to provide heat for the power battery, power assembly and passenger cabin in the electric vehicle, so that the power battery and power assembly work at a suitable temperature, thereby driving the electric vehicle to run normally and providing a comfortable driving environment for the user.

[0003] However, the PTC occupies a large space and has a high cost, and when the outside temperature is lower than the critical temperature at which the refrigerant absorbs heat (for example, minus twenty degrees Celsius or lower), the refrigerant in the thermal management system cannot absorb heat from the environment, which causes heat supply fluctuation and poor stability.

[0004] Therefore, how to provide a low-cost thermal management control method to control the thermal management system to realize rapid and stable heat supply for the passenger cabin of the electric vehicle has become a technical problem to be solved. SUMMARY

[0005] The present application provides a thermal management control method of an electric vehicle and the electric vehicle, which are used for realizing rapid and stable heat supply for the passenger cabin of the electric vehicle, such as controlling the thermal management system to realize rapid and stable heat supply for the passenger cabin of the electric vehicle when the outside temperature is lower than the critical temperature at which the refrigerant absorbs heat.

[0006] To achieve the above object, 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 is used to control a valve of a refrigerant circuit of the electric vehicle to provide heat for the electric vehicle. The refrigerant circuit includes a first valve, a second valve, a condenser, and a compressor. The compressor is used to compress refrigerant in the refrigerant circuit. An inlet of the second valve is connected to an outlet of the compressor and controls the flow of compressed refrigerant from the compressor. An outlet of the second valve is connected to an inlet of the compressor. An inlet of the condenser is connected to the outlet of the compressor through the first valve. An outlet of the condenser is connected to the inlet of the compressor. The first valve controls the flow of compressed refrigerant from the compressor. The condenser provides heat for an interior of the electric vehicle. The electric vehicle is in a low-temperature environment. The thermal management control method includes: in a case where the air conditioner of the electric vehicle starts to provide air in a situation where the air conditioner adjustment increases the amount of hot air, controlling the first valve of the refrigerant circuit to decrease the opening degree to a first preset valve opening degree, and controlling the second valve of the refrigerant circuit to increase the opening degree to a second preset valve opening degree.

[0008] In the above technical solution, the air conditioner adjustment of the electric vehicle increases the amount of hot air, which means that the current internal heat demand of the electric vehicle needs to increase the amount of hot air to provide heating for the passenger cabin, or the internal temperature of the electric vehicle is equal to the external environment temperature when the electric vehicle is started in a low-temperature environment, and the air conditioner needs to provide hot air to provide heating for the passenger cabin. The air conditioner adjustment of the electric vehicle increases the amount of hot air, which means that the current heating capacity is increased, and the actual heat production of the compressor cannot immediately adapt to the increased heating capacity. In the case where the air conditioner adjustment of the electric vehicle increases the amount of hot air at the first time, the opening degree of the first valve is controlled to decrease, and the opening degree of the second valve is controlled to increase, so that the refrigerant output from the compressor returns to the inlet of the compressor faster, avoiding the rapid decrease of the refrigerant pressure at the inlet of the compressor when the electric vehicle increases the amount of hot air, ensuring that the compressor can stably provide heat, and maintaining the stability of the triangular cycle to a certain extent, and improving the robustness of the triangular cycle.

[0009] Based on this, the thermal management control method for the electric vehicle provided by the embodiments of the present application can control the thermal management system of the electric vehicle to work normally without additional PTC in the case where the refrigerant in the refrigerant circuit cannot absorb heat from the outside (for example, the outside temperature is-20℃ or lower), so as to realize stable heating of the electric vehicle.

[0010] In any possible implementation form of the first aspect, the refrigerant circuit comprises a first heat exchanger, a first inlet of the first heat exchanger is configured to be connected to an outlet of the compressor via a second valve, a first outlet of the first heat exchanger is configured to be connected to an inlet of the compressor, a second inlet of the first heat exchanger is configured to be connected to an outlet of a first water pump of the electric vehicle cooling circuit, a second outlet of the first heat exchanger is configured to be connected to an interface of a multi-way valve of the electric vehicle cooling circuit, the first heat exchanger is configured to circulate and exchange heat between the refrigerant in the refrigerant circuit and the coolant in the cooling circuit, and the thermal management control method further comprises: controlling an opening degree of the first water pump to be less than a first water pump opening degree threshold at the first time.

[0011] In the possible implementation form above, in the case that the air conditioning of the electric vehicle increases the hot air flow at the first time, the opening degree of the first water pump is controlled to be less than the first water pump opening degree threshold, that is, the opening degree of the first water pump is reduced. Less coolant enters the first heat exchanger, and the heat exchangeable between the coolant and the refrigerant in the first heat exchanger is limited. In the case that the temperature of the coolant is lower than the temperature of the refrigerant, the heat exchanged from the refrigerant is also limited, and the heat can still be retained in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the pressure and the temperature of the refrigerant at the inlet of the compressor are also increased, so that the heat production of the compressor can be quickly adapted to the increased heat supply demand, which is beneficial to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby realizing stable heat supply of the electric vehicle.

[0012] In any possible implementation form of the first aspect, the refrigerant circuit further comprises an evaporator, a third valve, a fourth valve and a first pressure sensor, an outlet of the compressor is configured to be connected to an inlet of the first valve and an inlet of the second valve via the first pressure sensor respectively, the first pressure sensor is configured to measure a compressed refrigerant pressure output by the compressor, an inlet of the evaporator is configured to be connected to an outlet of the condenser and the first outlet of the first heat exchanger via the third valve respectively and circulate the compressed refrigerant, an outlet of the evaporator is configured to be connected to the inlet of the compressor, the evaporator is configured to supply heat to an interior of the electric vehicle, an inlet of the fourth valve is configured to be connected to the outlet of the condenser and the first outlet of the first heat exchanger and circulate the compressed refrigerant, an outlet of the fourth valve is configured to be connected to the inlet of the compressor, the third valve and the fourth valve are configured to control the flow of the compressed refrigerant, and the thermal management control method further comprises: at a second time after the first time, controlling the third valve opening degree to be reduced to a third preset valve opening degree and controlling the fourth valve opening degree to be increased to a fourth preset valve opening degree, in the case that an air outlet flow of the air conditioning changes by more than or equal to a first air outlet flow threshold and a pressure change value of the first pressure sensor is greater than or equal to a first pressure threshold.

[0013] The possible implementation manner described above, at the second time, the third valve opening degree is controlled to decrease, the compressed refrigerant flow passing through the evaporator can be reduced, the fourth valve opening degree is controlled to increase, the compressed refrigerant flow returning to the compressor inlet can be increased, and then the refrigerant pressure and temperature at the compressor inlet are increased, so that the heat production of the compressor can be quickly adapted to the increased heat supply demand, which is beneficial to maintaining the stability of the triangular cycle of the compressor, improves the robustness of the triangular cycle of the compressor, and enables the electric vehicle to stably supply heat.

[0014] In any possible implementation manner of the first aspect, the refrigerant circuit further comprises a second heat exchanger, a first inlet of the second heat exchanger is configured to be connected to an outlet of the fourth valve, a first outlet of the second heat exchanger is configured to be connected to an inlet of the compressor, a second inlet of the second heat exchanger is configured 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 configured to be connected to another interface of the multi-way valve, the second heat exchanger is configured to circulate the refrigerant in the refrigerant circuit and the cooling liquid in the cooling circuit and exchange heat therebetween, and the thermal management control method further comprises: at a second time, controlling an opening degree of the second water pump to be less than a second water pump opening degree threshold.

[0015] The possible implementation manner described above, at the second time, the opening degree of the second water pump is controlled to be less than the second water pump opening degree threshold, less cooling liquid enters the second water pump 112, and the heat exchanged with the refrigerant in the second heat exchanger is limited, in the case that the temperature of the cooling liquid is lower than the temperature of the refrigerant, the heat exchanged from the refrigerant is also limited, and the 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 are also increased, so that the heat production of the compressor can be quickly adapted to the increased heat supply demand, which is beneficial to maintaining the triangular cycle of the compressor and improving the robustness of the triangular cycle of the compressor, thereby realizing stable heat supply of the electric vehicle.

[0016] In any possible implementation manner of the first aspect, the thermal management control method further comprises: at a third time after the second time, the air outlet flow of the air conditioner changes by less than a first air outlet flow threshold, and the pressure change value of the first pressure sensor is less than a first pressure threshold, the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening degree change less than a first opening degree change value.

[0017] The possible implementation manner above, the air conditioner's air flow variation less than the first air flow threshold value indicates that the current air conditioner's air flow has reached a stable state, and the first pressure sensor's pressure variation value less than the first pressure threshold value indicates that the compressor output's compressed refrigerant pressure has reached a stable state. After the adjustment of the valve and the water pump at the first time and the second time, the engine's heat production and the heat supply demand have reached a balanced state at the third time, and the compressor's delta cycle can be maintained stable without further large-scale adjustment of the valve in the refrigerant circuit, so as to realize stable heat supply of the electric vehicle.

[0018] In any possible implementation manner of the first aspect, the refrigerant circuit further comprises a fifth valve connected between the inlet and the outlet of the compressor, the fifth valve being configured to control the flow of the compressed refrigerant from the outlet to the inlet of the compressor, and the heat management control method further comprises: when the variation of the hot air flow of the air conditioner of the electric vehicle is greater than a first air flow variation threshold value at a fourth time before the first time, controlling the compressor to start and work at a first rotating speed; controlling the fifth valve to increase to a fifth preset valve opening degree, and controlling the first valve to increase to a sixth preset valve opening degree, the fifth preset valve opening degree being greater than the sixth preset valve opening degree, and the sixth preset valve opening degree being greater than the first preset valve opening degree.

[0019] The possible implementation manner above, after starting the compressor at the fourth time, the compressor is controlled to work at the first rotating speed, and the fifth valve is opened, so that the refrigerant output from the compressor reenters the compressor through the fifth valve. Since the refrigerant output from the compressor is compressed refrigerant after compression treatment by the compressor, the pressure and temperature of the compressed refrigerant are higher than those of the refrigerant at the inlet of the compressor, so that 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. The opening of the first valve can deliver the compressed refrigerant output from the compressor to the condenser, so as to deliver heat to the passenger cabin through the condenser.

[0020] In any possible implementation manner of the first aspect, the refrigerant circuit further comprises an air conditioner box damper arranged on the same side of the condenser and the evaporator, the air conditioner box damper being configured to guide the air blowing to the condenser and the evaporator, and the heat management control method further comprises: controlling the air conditioner box damper of the air conditioner to be at an intermediate position towards the evaporator before the first time after the fourth time.

[0021] The possible implementation manner above, which directs the middle position of the air conditioning box damper towards the evaporator, can avoid blowing a large amount of heat in the condenser into the passenger cabin, thereby avoiding that the heat carried by the compressed refrigerant is excessively reduced to further cause the actual heat generation of the compressor to be reduced, so that the actual heat generation of the compressor can be increased to balance the heat supply of the passenger cabin as soon as possible, and the three-phase cycle of the compressor is beneficial to be maintained, thereby realizing stable heat supply of the electric vehicle.

[0022] In any of the possible implementation manners of the first aspect, the heat management control method further includes: at a fifth time moment after the third time moment, if the change value of the air conditioning switch is greater than the second air volume change threshold, the third valve opening is controlled to increase to a seventh preset valve opening, and the fourth valve opening is controlled to decrease to an eighth preset valve opening.

[0023] The possible implementation manner above, when the actual heat generation of the compressor is greater than the heat supply of the passenger cabin, the third valve opening is first controlled to increase and the fourth valve opening is controlled to decrease, so that more compressed refrigerant output from the compressor enters the evaporator rather than the second heat exchanger, and because the external temperature is extremely low, the heat that can be absorbed by the refrigerant when evaporating in the evaporator is also limited, so that the refrigerant at the compressor inlet does not cause the refrigerant pressure and fluctuation at the compressor inlet to be too large, to a certain extent, the stability of the three-phase cycle is maintained, the robustness of the three-phase cycle is improved, and the electric vehicle can still stably supply heat.

[0024] In any of the possible implementation manners of the first aspect, the heat management control method further includes: at a sixth time moment after the fifth time moment, if the air outlet flow of the air conditioner changes by greater than or equal to a second air outlet flow threshold and the pressure change value of the first pressure sensor is greater than or equal to a second pressure threshold, the first valve opening is controlled to increase to a ninth preset valve opening, and the second valve opening is controlled to decrease to a tenth preset valve opening.

[0025] The possible implementation manner above, when the actual heat generation of the compressor is greater than the heat supply of the passenger cabin, the first valve opening is controlled to be greater than the second valve opening, so that more compressed refrigerant output from the compressor enters the condenser rather than the first heat exchanger, the heat in the condenser is blown to the passenger cabin by the air blower, so that the heat carried by the compressed refrigerant is blown into the passenger cabin more, the refrigerant pressure and temperature at the compressor inlet are reduced, to a certain extent, the stability of the three-phase cycle is maintained, the robustness of the three-phase cycle is improved, and the electric vehicle can still stably supply heat.

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

[0027] The possible implementation manner described above, at the seventh moment, the opening degree of the second water pump is greater than the third water pump opening degree threshold value, the cooling liquid entering the second heat exchanger increases, the heat capable of being exchanged with the refrigerant in the second heat exchanger increases, in the case that the temperature of the cooling liquid is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also more, and the heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the refrigerant pressure and the temperature at the inlet of the compressor will not be greatly increased, so that the actual heat generation of the compressor can be quickly matched with the reduced heat supply of the passenger compartment, which is beneficial to maintaining the triangular cycle of the compressor, improves the robustness of the triangular cycle of the compressor, and thus realizes stable heat supply of the electric vehicle.

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

[0029] The possible implementation manner described above, at the seventh moment, the opening degree of the first water pump is greater than the fourth water pump opening degree threshold value, the cooling liquid entering the first heat exchanger increases, the heat capable of being exchanged with the refrigerant in the first heat exchanger increases, in the case that the temperature of the cooling liquid is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also more, and the heat in the refrigerant circuit decreases. When the refrigerant in the refrigerant circuit returns to the inlet of the compressor, the refrigerant pressure and the temperature at the inlet of the compressor will not be greatly increased, so that the actual heat generation of the compressor can be quickly matched with the reduced heat supply of the passenger compartment, which is beneficial to maintaining the triangular cycle of the compressor, improves the robustness of the triangular cycle of the compressor, and thus realizes stable heat supply of the electric vehicle.

[0030] In any possible implementation manner of the first aspect, the heat management control method further includes: at the seventh moment, controlling the compressor to work at a second rotating speed, the second rotating speed being less than the first rotating speed.

[0031] The possible implementation manner described above, in the embodiment of the application, when the actual heat generation of the compressor is greater than the heat supply of the passenger compartment, the rotating speed of the compressor is reduced to further reduce the actual heat generation of the compressor, so that the actual heat generation of the compressor can be quickly adjusted to be balanced with the reduced heat supply of the passenger compartment, which is beneficial to maintaining the triangular cycle of the compressor, and thus realizes stable heat supply of the electric vehicle.

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

[0033] The above possible implementation manner, the air outlet flow of the air conditioner is less than the second air outlet flow threshold, which indicates that the air outlet flow of the current air conditioner has reached a stable state, and the pressure change value of the first pressure sensor is less than the second pressure threshold, which indicates that the compressed refrigerant pressure output by the compressor has reached a stable state. That is, after the adjustment of the valve and the water pump at the fifth time, the sixth time and the seventh time, the actual heat output of the compressor and the heat supply of the passenger compartment have reached a balanced state at the eighth time, and the triangular cycle of the compressor can be maintained stable without further adjusting the valve in the refrigerant circuit.

[0034] In any possible implementation manner of the first aspect, the heat management control method further includes: controlling the air conditioner box damper to be in the middle position towards the condenser before the fifth time after the third time.

[0035] The above possible implementation manner, before adjusting the valve, the air conditioner box damper is controlled to be in the middle position towards the condenser, so that a large amount of heat in the condenser can be blown into the passenger compartment, thereby reducing the heat carried by the compressed refrigerant, and the actual heat output of the compressor can be adjusted to balance the heat supply of the passenger compartment as soon as possible, which is beneficial to maintaining the triangular cycle of the compressor, thereby realizing stable heat supply of the electric vehicle.

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

[0037] It can be understood that the electric vehicle provided above can achieve the beneficial effects corresponding to the beneficial effects of the heat management control method of the electric vehicle provided above, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0040] Figure 3 A second structure schematic diagram of a heat management system provided by an embodiment of the present application;

[0041] Figure 4 A third structure schematic diagram of a heat management system provided by an embodiment of the present application;

[0042] Figure 5 A fourth structure schematic diagram of a heat management system provided by an embodiment of the present application;

[0043] Figure 6A fifth structure schematic diagram of the heat management system provided by the embodiment of the present application is shown in the following figure;

[0044] Figure 7 A timing diagram of the valve opening degree in the refrigerant circuit provided by the embodiment of the present application is shown in the following figure;

[0045] Figure 8 A timing diagram of the water pump opening degree in the cooling circuit provided by the embodiment of the present application is shown in the following figure. DETAILED DESCRIPTION

[0046] In the present application, “in an embodiment” is used to represent an example, illustration or description. The scheme described as “in an embodiment” in the present application should not be interpreted as more preferred or more advantageous than the scheme of other embodiments. In fact, the use of “in an embodiment” aims to present the inventive concept of the present application in a specific way.

[0047] Figure 1 A schematic diagram of the electric vehicle provided by the embodiment of the present application is shown in the following figure. Figure 1 As shown in the figure, the electric vehicle 01 includes a heat management system 10, a passenger cabin 20, a power assembly 30 and a power battery 40. The heat management system 10 is used to manage the heat of the passenger cabin 20, the power assembly 30 and the power battery 40. For example, the heat management system 10 can absorb heat from the passenger cabin 20, the power assembly 30 and the power battery 40, and the heat management system 10 can also release heat to the passenger cabin 20, the power assembly 30 and the power battery 40. In addition, the heat management system 10 can also absorb heat from the external environment or release heat to the external environment. In this way, through the transfer and control of heat, not only can the power assembly 30 and the power battery 40 work at a suitable temperature, but also the passenger cabin 20 can be provided with a suitable temperature, thereby providing a comfortable driving environment for the user.

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

[0049] When the PTC is used as the heat source, on the one hand, the PTC has a large volume, which occupies limited space in the electric vehicle 01. On the other hand, the PTC needs to work by using electric energy, and the heating accelerates the consumption of electric energy, which reduces the endurance time and endurance mileage of the electric vehicle 01, and affects the driving experience of the user. When the heat pump is used for heating, it depends on whether the refrigerant can absorb heat from the external environment. In the case where the external temperature is-20℃ or lower, the external environment has no heat to provide for the refrigerant, which causes the heat pump to fail, and thus the heat management system fails.

[0050] To solve the above problems, the present application provides an electric vehicle heat management control method and an electric vehicle. The heat management control method provided by 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 realized by maintaining the triangular cycle of the compressor. The triangular cycle refers to connecting the outlet and the inlet of the compressor, using the rotation speed of the compressor to generate heat as a heat source, and outputting compressed refrigerant by the compression process of the compressor. When the compressed refrigerant returns to the inlet of the compressor, the temperature of the refrigerant at the inlet of the compressor is increased, thereby establishing a cycle of suction, compression and exhaust of the compressor, and realizing stable heating of the compressor. In this way, in the case where the refrigerant in the refrigerant circuit cannot absorb heat from the external environment (for example, the external temperature is-20℃ or lower), the heat management system can work normally without using the PTC, thereby realizing stable heating of the electric vehicle 01.

[0051] The electric vehicle provided by the present application can be an electric vehicle 01 as shown in Figure 1 The heat management control method can be realized by a control device of a heat management system. The control device of the heat management system can be an independent integrated controller chip, or can be deployed in an air conditioner controller or a vehicle controller of the electric vehicle, or can be deployed in a left vehicle body controller or a right vehicle body controller. The present application does not make specific limitation thereto.

[0052] For the electric vehicle 01, the heating amount Q1 of the passenger compartment and the actual heat generation amount Q2 of the compressor 101 satisfy the following formula: Q1=A*Q2. Wherein, A represents the safety factor (coefficient of performance, COP). For example, in the case where the external temperature is-20℃, the range of A is 0.75-0.85.

[0053] In one possible implementation, Q1 is positively correlated with the airflow of the blower in the passenger compartment, the outlet air temperature of the air conditioning unit, or the inlet air temperature of the air conditioning unit. That is, when any one of the parameters of the blower airflow, the outlet air temperature, and the inlet air temperature of the air conditioning unit increases, the heat supply Q1 of the passenger compartment also increases; when any one of the aforementioned parameters decreases, the heat supply Q1 of the passenger compartment also decreases.

[0054] In one possible implementation, Q2 is positively correlated with the suction pressure, discharge pressure, or rotational speed of the compressor 101. That is, when any one of the suction pressure, discharge pressure, or rotational speed of the compressor 101 increases, the actual heat output Q2 of the compressor 101 also increases; when any one of the aforementioned parameters decreases, the actual heat output Q2 of the compressor 101 also decreases.

[0055] When the heating capacity Q1 of the passenger compartment changes significantly, for example, when a user adjusts the air conditioning fan speed to maximum or minimum, the actual heat output Q2 of the compressor 101 cannot quickly adjust to provide adequate heating, which disrupts the triangular circulation of the compressor 101. The thermal management control method provided in this application can maintain the triangular circulation of the compressor 101 to a certain extent when the heating capacity Q1 of the passenger compartment changes significantly, allowing the electric vehicle 01 to provide stable heating.

[0056] To facilitate understanding of the thermal management control method provided in the embodiments of this application, the technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings.

[0057] In one embodiment, the thermal management system 10 includes a refrigerant circuit. For example... 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 connect to the outlet of the compressor 101 and control the flow rate of the compressed refrigerant output by the compressor 101. The outlet of the second valve 104 is used to connect to the inlet of the compressor 101. The inlet of the condenser 102 is used to connect to the outlet of the compressor 101 through the first valve 103. The outlet of the condenser 102 is used to connect 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 compressor 101. The condenser 102 is used to supply heat to the interior of the electric vehicle 01, which is in a low-temperature environment.

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

[0059] In addition, valve opening degree indicates the size of the valve's opening diameter. A larger valve opening degree means a larger opening diameter, and consequently, more medium passes through the valve; a smaller valve opening degree means a smaller opening diameter, and less medium passes through the valve. For example, a larger opening degree for the first valve 103 indicates more refrigerant passing through it.

[0060] The aforementioned first valve 103 connects 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 compressed refrigerant from the compressor 101 into the condenser 102 increases; conversely, if the opening of the first valve 103 decreases, the flow rate of compressed refrigerant from the compressor 101 into the condenser 102 decreases. When the first valve 103 is open, the refrigerant flowing from the outlet of the compressor 101 can flow into the condenser 102 through the first valve 103. The condenser 102 condenses the passing refrigerant, releasing the heat carried in the compressed refrigerant during condensation. After the air conditioner starts blowing air, the heat from the condenser 102 is blown into the passenger compartment, thus providing heating to the passenger compartment.

[0061] The inlet of the second valve 104 is connected to the outlet of the compressor 101 and controls the flow rate of the compressed refrigerant output from the compressor 101. The outlet of the second valve 104 is connected 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; 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 such Figure 2 The structure shown in this application embodiment includes the following thermal management control method: when the air conditioning of the electric vehicle 01 increases the hot air volume at a first moment, the air conditioning starts to blow air, the first valve 103 of the refrigerant circuit is controlled to decrease its opening to a first preset valve opening, and the second valve 104 of the refrigerant circuit is controlled to increase its opening to a second preset valve opening.

[0063] Specifically, increasing the hot air volume in the air conditioning system of electric vehicle 01 refers to a situation where the current internal temperature of 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. Alternatively, it refers to a situation where, when electric vehicle 01 is first started, the internal temperature is the same as the external ambient temperature, and the air conditioning system urgently needs to provide hot air to heat the passenger compartment. Increasing the hot air volume in the air conditioning system of electric vehicle 01 means that the current Q1 increases, but the actual heat output Q2 of compressor 101 cannot immediately match the increased Q1, i.e., Q2 < Q1.

[0064] In addition, the first preset valve opening degree can be greater than the second preset valve opening degree, or can be less than or equal to the second preset valve opening degree, which is not limited in the embodiments of the present application. The first preset valve opening degree is used to indicate that the opening degree of the first valve 103 at the first time is less than the opening degree before the first time. Similarly, the second preset valve opening degree is used to indicate that the opening degree of the second valve 104 at the first time is greater than the opening degree before the first time.

[0065] In a possible implementation, the size relationship between the first preset valve opening degree and the second preset valve opening degree 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), because the caliber of the EXV is inconsistent with the caliber of the ERV, there is no absolute size relationship between the first preset valve opening degree and the second preset valve opening degree.

[0066] If the opening degree of the first valve 103 is increased, more compressed refrigerant output by the compressor 101 will flow into the condenser 102, and the flow of compressed refrigerant into the compressor 101 will decrease, which will further cause the temperature of the refrigerant at the inlet of the compressor 101 to be unable to be quickly increased, and finally cause the triangular cycle of the compressor 101 to be destroyed.

[0067] Based on this, in the case that the air conditioning regulation of the electric vehicle 01 is increased to increase the hot air flow, the opening degree of the first valve 103 is controlled to be reduced, and the opening degree of the second valve 104 is controlled to be increased, so that the refrigerant output from the compressor 101 can return to the inlet of the compressor 101 more quickly. This avoids the rapid decrease of the refrigerant pressure at the inlet of the compressor 101 when the electric vehicle 01 increases the hot air flow, ensures that the compressor 101 can stably supply heat, and to some extent, maintains the stability of the triangular cycle, and can improve the robustness of the triangular cycle. In this way, in the case that the refrigerant in the refrigerant circuit cannot absorb heat from the outside (for example, the outside temperature is-20℃ or lower), the PTC does not need to be additionally arranged, and the heat management system of the electric vehicle 01 can be controlled to work normally, so that the stable heat supply of the electric vehicle 01 is realized.

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

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

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

[0071] In addition, the aforementioned mutual heat exchange means that the heat carried in the refrigerant can be transferred to the coolant. In this way, 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 electric vehicle 01 increases the hot air volume, the opening degree of the first water pump 106 is controlled to be less than the first water pump opening threshold. This results in less coolant entering the first heat exchanger 105, limiting the amount of heat that can be exchanged with the refrigerant in the first heat exchanger 105. Since the coolant temperature is lower than the refrigerant temperature, the amount of heat exchanged from the refrigerant is also limited, and more heat remains in the refrigerant circuit. When the refrigerant in the refrigerant circuit returns to the inlet of compressor 101, it also increases the refrigerant pressure and temperature at the compressor 101 inlet, allowing Q2 to quickly adapt to the increased Q1. This helps maintain the triangular cycle of compressor 101, improving the robustness of the triangular cycle and thus achieving stable heating for electric vehicle 01.

[0073] It is understood that the aforementioned multi-way valve 107 can be a nine-way valve with nine different ports. The aforementioned multi-way valve can also be a six-way valve, seven-way valve, eight-way valve, or other types of multi-way valves. Compared to a nine-way valve, six-way and seven-way valves have fewer ports, making them more cost-effective. If there are many branches in the cooling circuit that need to be connected, a nine-way or eight-way valve with more ports can be selected; if there are fewer branches in the cooling circuit that need to be connected, a six-way or seven-way valve with fewer ports can be selected. This is provided as an example and not as a limitation. Figure 3Only two 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, and the second outlet of the first heat exchanger 105 is used to connect to port 2 of the multi-way valve 107.

[0074] In one embodiment, such as 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 connected to the inlet of the first valve 103 and the inlet of the second valve 104 via 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 connected to the outlet of the condenser 102 and the first outlet of the first heat exchanger 105 via the third valve 109, allowing the compressed refrigerant to flow through. The outlet of the evaporator 108 is connected to the inlet of the compressor 101, and the evaporator 108 is used to supply heat 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, allowing the compressed refrigerant to flow through. The outlet of the fourth valve 110 is 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 connected to the inlet of the evaporator 108, and the inlet of the third valve 109 is 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 degree of the third valve 109 increases, the flow rate of the compressed refrigerant entering the evaporator 108 will increase; if the opening degree 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 open, the compressed refrigerant can flow into the evaporator 108 through the third valve 109, and the evaporator 108 is used to evaporate the passing refrigerant.

[0076] The outlet of the aforementioned fourth valve 110 is connected to the inlet of the compressor 101, and 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. The fourth valve 110 is used to control the flow rate of the compressed refrigerant. If the opening degree 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; if the opening degree 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 such Figure 4The structure shown in this application embodiment further includes the following thermal management control method: at a second time after the first time, if the change in the airflow of the air conditioner is greater than or equal to the first airflow threshold and the pressure change value of the first pressure sensor PT1 is greater than or equal to the first pressure threshold, the opening degree of the third valve 109 is controlled to decrease to the third preset valve opening degree, and the opening degree of the fourth valve 110 is controlled to increase to the fourth preset valve opening degree.

[0078] Specifically, a change in the airflow rate of the air conditioner greater than or equal to the first airflow rate threshold indicates that the airflow rate of the air conditioner is unstable, and a change in the pressure value of the first pressure sensor PT1 greater than or equal to the first pressure threshold indicates that the pressure of the compressed refrigerant output by the compressor 101 is unstable. In other words, after adjusting the valves and water pump in the first moment, it is necessary to continue adjusting the valves in the refrigerant circuit and the water pump in the cooling circuit in the second moment.

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

[0080] Based on the above technical solution, at the second moment, controlling the opening of the third valve 109 to decrease can reduce the flow of compressed refrigerant through the evaporator 108, and controlling the opening of the fourth valve 110 to increase 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. This allows Q2 to quickly adapt to the increased Q1, which is beneficial to maintaining the stability of the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, enabling the electric vehicle 01 to provide stable heating.

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

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

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

[0084] At the second time, the opening degree of the second water pump 112 is controlled to be less than the second water pump opening degree threshold value, less cooling liquid enters the second heat exchanger 111, and the heat exchangeable with the refrigerant in the second heat exchanger 111 is limited. In the case where the temperature of the cooling liquid 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 pressure and temperature of the refrigerant at the inlet of the compressor 101 are also increased, so that Q2 can be quickly adapted to the increased Q1, which is beneficial to maintaining the triangular cycle of the compressor 101 and improving the robustness of the triangular cycle of the compressor 101, thereby realizing 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 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, the second outlet of the first heat exchanger 105 is used to be connected to the port 2 of the multi-way valve 107, the second outlet of the second heat exchanger 111 is used to be connected to the port 3 of the multi-way valve 107, and the inlet of the second water pump 112 is used to be connected to the port 4 of the multi-way valve 107.

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

[0087] Wherein, the air conditioner outlet flow rate change less than the first outlet flow rate threshold value indicates that the current air conditioner outlet flow rate has reached a stable state, and the pressure change value of the first pressure sensor PT1 less than the first pressure threshold value indicates that the compressed refrigerant pressure output by the compressor 101 has reached a stable state. That is, after the adjustment of the valves and water pumps at the first time and the second time, Q2 and Q1 have reached a balanced state at the third time.

[0088] In addition, the valve opening degree change less than the first opening degree change value is used to indicate that the valve opening degree change is small or no change. That is, after Q2 and Q1 reach a balanced state, the valves in the refrigerant circuit do not need to be adjusted greatly to maintain the stable triangular cycle of the compressor 101.

[0089] In an embodiment, as Figure 5 shown, the refrigerant circuit further comprises a fifth valve 113, the fifth valve 113 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 flow of the compressed refrigerant from the outlet to the inlet of the compressor 101.

[0090] The heat management control method further comprises: at a fourth time point before the first time point, if a change value of the hot air volume of the air conditioning switch of the electric vehicle 01 is greater than a first air volume change threshold, controlling the compressor 101 to start and work at a first rotating speed; controlling the opening degree of the fifth valve 113 to increase to a fifth preset valve opening degree, and controlling the opening degree of the first valve 103 to increase to a sixth preset valve opening degree, the fifth preset valve opening degree being greater than the sixth preset valve opening degree, and the sixth preset valve opening degree being greater than the first preset valve opening degree.

[0091] The fourth time point T4 is a time point at which the change value of the hot air volume of the air conditioning switch is greater than the first air volume change threshold, that is, a time point at which the heating function of the electric vehicle 01 is started and the triangular cycle is established. In a possible implementation, whether there is a heating demand at present is determined by receiving parameters such as an external temperature, an actual temperature of a passenger compartment, a set temperature of the passenger compartment, a body temperature of a driving motor, and a temperature of a power battery 40. If the external temperature is lower than a critical temperature at which the refrigerant absorbs heat (for example, the external temperature is -20℃), or the actual temperature of the passenger compartment is lower than the set temperature of the passenger compartment, or the body temperature of the driving motor and the temperature of the power battery 40 are both lower than the temperature required during normal work, it is indicated that there is a demand to establish the triangular cycle of the compressor 101. If the external temperature is higher than the critical temperature at which 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 driving motor and the temperature of the power battery 40 are not lower than the temperature required during normal work, it is indicated that the triangular cycle of the compressor 101 is not needed to be established.

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

[0093] Furthermore, the opening degree of the fifth valve 113 is greater than the fifth preset valve opening degree, indicating that the fifth valve 113 is open and allows at least a partial return of the refrigerant at the outlet of the compressor 101 to the inlet of the compressor 101. The opening degree of the first valve 103 increases to the sixth preset valve opening degree, indicating that the first valve 103 is open and allows at least a partial flow of the refrigerant at the outlet of the compressor 101 into the condenser 102. The opening degree of the fifth preset valve is greater than the opening degree of the sixth preset valve, 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 opening degree of the sixth preset valve is greater than the preset opening degree of the first valve, indicating that the first valve 103 had a larger opening degree in the fourth moment before the first moment, and a smaller opening degree in the first moment after the fourth moment.

[0094] After starting compressor 101, it is controlled to operate at a first speed, and the fifth valve 113 is opened to allow the refrigerant output from compressor 101 to re-enter compressor 101 through the fifth valve 113. Since the refrigerant output from compressor 101 is compressed refrigerant after being processed by compressor 101, its pressure and temperature are higher than those of the refrigerant at the compressor 101 inlet. Therefore, when the compressed refrigerant flows through the fifth valve 113 to the compressor 101 inlet, it increases the pressure and temperature of the refrigerant at the compressor 101 inlet, thus enabling compressor 101 to operate normally. Opening the first valve 103 allows the compressed refrigerant output from compressor 101 to be transferred to condenser 102, thereby transferring heat to the passenger compartment through condenser 102.

[0095] In one embodiment, such as Figure 6 As shown, the refrigerant circuit also includes an air conditioning unit damper 114, which is located on the same side of the condenser 102 and the evaporator 108. The air conditioning unit damper 114 is used to guide the air blowing towards the condenser 102 and the evaporator 108.

[0096] The thermal management control method also includes: after the fourth moment and before the first moment, controlling the air conditioning unit damper 114 of the air conditioner to be oriented towards the evaporator 108 at its middle position.

[0097] If the air conditioning box damper 114 is towards the condenser 102, the heat in the condenser 102 will be blown into the passenger cabin, thereby reducing the heat carried by the compressed refrigerant, and further reducing the pressure and temperature of the compressed refrigerant returning to the inlet of the compressor 101. The low pressure and temperature of the refrigerant at the inlet of the compressor 101 will further reduce Q2, which will further disrupt the balance between Q2 and Q1. Therefore, the middle position of the air conditioning box damper 114 towards the evaporator 108 can avoid blowing a large amount of heat in the condenser 102 into the passenger cabin, thereby avoiding too much reduction of the heat carried by the compressed refrigerant, avoiding further reduction of Q2, and enabling Q2 to be adjusted to balance with Q1 as soon as possible, which is conducive to maintaining the triangular cycle of the compressor 101, thereby realizing stable heating of the electric vehicle 01.

[0098] In an embodiment, as shown in Figure 6 The refrigerant circuit further includes a gas-liquid separator 115 connected between the inlet of the compressor 101 and the fifth valve 113. The gas-liquid separator 115 can separate the gas-liquid mixture 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 an embodiment, as shown in Figure 6 The refrigerant circuit further includes a sixth valve 116 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 of compressed refrigerant entering the compressor 101.

[0100] In an embodiment, as shown in Figure 6 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, which are used to prevent backflow of the medium. The first check valve CV1 is arranged between the first outlet of the first heat exchanger 105 and the outlet of the condenser 102, which 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, which 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, which 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 an embodiment, as shown in Figure 6As shown, the refrigerant circuit also includes multiple pressure and temperature sensors. For example, the refrigerant circuit also includes a second pressure and temperature sensor PT2 and a third pressure and temperature sensor PT3. The second pressure and temperature sensor PT2 is located 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 located 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 changes of the compressor 101 when the first pressure and temperature sensor PT1 fails. They can also be used to provide parameters such as the compressor's suction pressure and temperature, and the condenser's discharge pressure and temperature, in order to accurately calculate the heat supply Q1 of the passenger compartment and the actual heat output Q2 of the compressor 101.

[0102] In one embodiment, such as 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 located between the coolant inlet of the powertrain 30 and the outlet of the first water pump 106, and is used to measure the inlet water temperature of the drive motor; the second temperature sensor NTC2 is located between the coolant inlet of the power battery 40 and port 6 of the multi-way valve 107, and is used to measure the inlet water temperature of the power battery 40.

[0103] In one embodiment, such as Figure 6 As shown, the third valve 109, the fourth valve 110, and the fifth valve 113 can all be EXV, and the first valve 103, the second valve 104, and the sixth valve 116 can all be ERV. The types of valves described above are for illustrative purposes only. In practical applications, the valves can all be EXV, ERV, or other types of valves. This application does not specifically limit the types of valves described above.

[0104] Reference Figure 6 It can be seen that the refrigerant flowing out of the compressor 101 outlet can directly return to the compressor 101 inlet through the fifth valve 113, or it can 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 condenser 102 outlet can return to the compressor 101 inlet through the refrigerant flow channel of the evaporator 108, 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 return to the compressor 101 inlet through the refrigerant flow channel of the evaporator 108, the second heat exchanger 111, or the sixth valve 116 respectively. That is to say, the refrigerant flowing out of the compressor 101 outlet can return to the compressor 101 inlet through the above multiple paths, thereby realizing the refrigerant circulation in the refrigerant circuit.

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

[0106] The following describes the structure shown in FIG. 1 as an example to introduce in detail the thermal management control method provided by the embodiment of the present application when Q1 < Q2. Figure 7

[0107] At the fifth time after the third time, the change value of the hot air volume of the air conditioner switch is greater than the second air volume change threshold, and the thermal management control method provided by the embodiment of the present application further includes: controlling the third valve 109 to increase the opening degree to a seventh preset valve opening degree, and controlling the fourth valve 110 to decrease the opening degree to an eighth preset valve opening degree.

[0108] The change value of the hot air volume of the air conditioner switch being greater than the second air volume change threshold indicates that the degree of reducing the hot air volume by operating the air conditioner switch is large.

[0109] In the embodiment of the present application, when Q1 > Q2, the opening degree of the third valve 109 is first controlled to increase and the opening degree of the fourth valve 110 is controlled to decrease, so that more refrigerant output from the compressor 101 enters the evaporator 108 rather than the second heat exchanger 111, and because the outside temperature is extremely low, the heat that can be absorbed by the refrigerant when evaporating in the evaporator 108 is also limited, so that the refrigerant transferred to the inlet of the compressor 101 does not cause the refrigerant pressure and fluctuation of the inlet of the compressor 101 to be large, 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 heat supply demand decreases, the suction pressure of the compressor 101 can be adjusted by controlling the opening degrees of the third valve 109 and the fourth valve 110, so that the stability of the triangular cycle of the compressor 101 can be maintained, and the triangular cycle is avoided from being destroyed, so that the electric vehicle 01 can still stably supply heat.

[0111] ​At the sixth time after the fifth time, 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 a second pressure threshold, and the thermal management control method further comprises: controlling the first valve 103 opening degree to increase to a ninth preset valve opening degree, and the second valve 104 opening degree to decrease to a tenth preset valve opening degree.

[0112] Wherein, 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, indicating that at the sixth time, after the third valve 109 opening degree and the fourth valve 110 opening degree control, Q1 and Q2 still do not satisfy the balance state, and the valve opening degree in the refrigerant circuit needs to be adjusted continuously.

[0113] If the second valve 104 opening degree is controlled to be larger, more refrigerant output from the compressor 101 will pass 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. In the case that the rotating speed of the compressor 101 is unchanged, the over-temperature and over-pressure of the compressor 101 will occur, thereby causing danger.

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

[0115] At the seventh time after the sixth time, 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 thermal management control method further comprises: controlling the opening degree of the second water pump 112 to be greater than a third water pump opening degree threshold.

[0116] Wherein, the opening degree of the second water pump 112 being greater than the third water pump opening degree threshold indicates that the opening degree of the second water pump 112 is increased.

[0117] At the seventh moment, the opening degree of the second water pump 112 is greater than the third water pump opening degree threshold, the cooling liquid entering the second heat exchanger 111 increases, the heat that can be exchanged with the refrigerant in the second heat exchanger 111 increases, and in the case that the temperature of the cooling liquid is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also more, and the 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 be greatly increased, so that Q2 can be quickly adapted to the reduced Q1, which is conducive to maintaining the triangular cycle of the compressor 101, improves the robustness of the triangular cycle of the compressor 101, and thus realizes stable heating of the electric vehicle 01.

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

[0119] Wherein, the opening degree of the first water pump 106 being greater than the fourth water pump opening degree threshold means that the opening degree of the first water pump 106 is increased.

[0120] At the seventh moment, the opening degree of the first water pump 106 is greater than the fourth water pump opening degree threshold, the cooling liquid entering the first heat exchanger 105 increases, the heat that can be exchanged with the refrigerant in the first heat exchanger 105 increases, and in the case that the temperature of the cooling liquid is lower than the temperature of the refrigerant, the heat exchanged out of the refrigerant is also more, and the 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 be greatly increased, so that Q2 can be quickly adapted to the reduced Q1, which is conducive to maintaining the triangular cycle of the compressor 101, improves the robustness of the triangular cycle of the compressor 101, and thus realizes stable heating of the electric vehicle 01.

[0121] At the seventh moment, the heat management control method further includes: controlling the compressor 101 to work at a second rotating speed, the second rotating speed being less than the first rotating speed.

[0122] From the foregoing, it can be known that the actual heat generation Q2 of the compressor 101 is related to the rotating speed of the compressor, the greater the rotating speed of the compressor, the greater Q2, and vice versa, the smaller the rotating speed, the smaller Q2.

[0123] In the embodiment of the application, when Q1 < Q2, the rotating speed of the compressor 101 is reduced to further reduce the actual heat generation Q2 of the compressor 101, so that Q2 can be quickly adjusted to balance the reduced Q1, which is conducive to maintaining the triangular cycle of the compressor 101, thereby realizing stable heating of the electric vehicle 01.

[0124] At an eighth time instant after the seventh time instant, the air conditioner's outlet flow rate change is less than the second outlet flow rate threshold and the first pressure sensor's pressure change value is less than the second pressure threshold, the thermal management control method further comprises: controlling the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 to keep the valve opening degree less than the second opening degree change value.

[0125] Wherein, the air conditioner's outlet flow rate change less than the second outlet flow rate threshold means that the current air conditioner's outlet flow rate has reached a stable state, and the first pressure sensor PT1's pressure change value less than the second pressure threshold means that the compressor 101 output's compressed refrigerant pressure has reached a stable state. That is to say, after the adjustment of the valves and the water pump at the fifth time instant, the sixth time instant and the seventh time instant, Q2 and Q1 have reached a balanced state at the eighth time instant.

[0126] In addition, the valve opening degree change less than the second opening degree change value is used to indicate that the valve opening degree change is small or no change. That is to say, after Q2 and Q1 reach a balanced state, the valves in the refrigerant circuit do not need to be adjusted greatly to maintain the compressor 101's triangular cycle stable.

[0127] The thermal management control method further comprises: controlling the air conditioner's air conditioner box damper 114 to be in the middle position towards the condenser 102 before the fifth time instant after the third time instant.

[0128] If the air conditioner box damper 114 is in the middle position towards the evaporator 108, the refrigerant will absorb heat when evaporating in the evaporator 108, which will further increase the suction pressure and discharge 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 rise, and Q2 and Q1 cannot be balanced. Therefore, by controlling the air conditioner box damper 114 to be in the middle position towards the condenser 102, a large amount of heat in the condenser 102 can be blown into the passenger cabin, 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 compressor 101's triangular cycle, thereby realizing stable heating of the electric vehicle 01.

[0129] The following combination Figure 8 and Figure 7 detailed description in the air conditioner switch increases or decreases the hot air volume, the change process of the valve opening degree in the refrigerant circuit and the water pump opening degree in the cooling circuit. Wherein, Figure 8 and ​ The broken line shown in and only represents the change trend of the valve opening degree and the water pump opening degree, and does not represent the specific numerical value correspondence.

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

[0131] At the first time T1, the air conditioner of the electric vehicle 01 starts to blow air under the condition that the air conditioner adjusts to increase the hot air volume, the control first valve 103 reduces the opening degree to the first preset valve opening degree, and the control second valve 104 increases the opening degree to the second preset valve opening degree.

[0132] At the second time T2, the air conditioner outflow changes greater than or equal to the first outflow threshold and the first pressure sensor PT1 pressure change value greater than or equal to the first pressure threshold, the control third valve 109 opening degree reduces to the third preset valve opening degree, and the control fourth valve 110 opening degree increases to the fourth preset valve opening degree.

[0133] At the third time T3, the air conditioner outflow changes less than the first outflow threshold and the first pressure sensor PT1 pressure change value less than the first pressure threshold, indicating that Q2 and Q1 have reached a balanced state, at this time there is no need to make a large adjustment to the valve in the refrigerant circuit, that is, the control first valve 103, second valve 104, third valve 109 and fourth valve 110 control valve opening degree change less than the first opening degree change value.

[0134] After Q1 and Q2 reach the balanced state, when the air conditioner switch reduces the hot air volume change value greater than the second air volume change threshold, it indicates that the current Q1>Q2.

[0135] Then at the fifth time T5, the air conditioner switch reduces the hot air volume change value greater than the second air volume change threshold, the control third valve 109 opening degree increases to the seventh preset valve opening degree, and the control fourth valve 110 opening degree reduces to the eighth preset valve opening degree.

[0136] At the sixth time T6, the air conditioner outflow changes greater than or equal to the second outflow threshold and the first pressure sensor pressure change value greater than or equal to the second pressure threshold, the control first valve 103 opening degree increases to the ninth preset valve opening degree, and the control second valve 104 opening degree reduces to the tenth preset valve opening degree.

[0137] At the seventh time T7, the air conditioner outflow changes greater than or equal to the second outflow threshold and the first pressure sensor pressure change value greater than or equal to the second pressure threshold, the control second water pump 112 opening degree greater than the third water pump opening degree threshold, and the control first water pump 106 opening degree greater than the fourth water pump opening degree threshold.

[0138] At the eighth time T8, the air outlet flow of the air conditioner changes less than the second air outlet flow threshold value and the pressure change value of the first pressure sensor is less than the second pressure threshold value, indicating that Q2 and Q1 have reached a balanced state, at which time it is not necessary to make a large adjustment to the valve in the refrigerant circuit, that is, the control of the first valve 103, the second valve 104, the third valve 109 and the fourth valve 110 control valve opening change is less than the second opening change value.

[0139] In an embodiment, an electric vehicle 01 is provided, which uses the above-mentioned heat management control method to adjust the temperature in 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 change or replacement within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electric vehicle thermal management control method, characterized by, The heat management control method is used for controlling the valves of the electric vehicle refrigerant circuit to realize the heating of the electric vehicle, the refrigerant circuit comprising a first valve, a second valve, a condenser, and a compressor for compressing the refrigerant in the refrigerant circuit for heating, an inlet of the second valve being connected to an outlet of the compressor and controlling the flow of compressed refrigerant output by the compressor, an outlet of the second valve being connected to an inlet of the compressor, an inlet of the condenser being connected to an outlet of the compressor through the first valve, an outlet of the condenser being connected to an inlet of the compressor, the first valve being used for controlling the flow of compressed refrigerant output by the compressor, the condenser being used for heating the interior of the electric vehicle, the electric vehicle being in a low-temperature environment, the heat management control method comprising: In the case that the air conditioning of the electric vehicle increases the hot air volume at the first time, the air conditioning starts to blow air, the first valve of the refrigerant circuit is controlled to reduce the opening degree to a first preset valve opening degree, and the second valve of the refrigerant circuit is controlled to increase the opening degree to a second preset valve opening degree.

2. The thermal management control method of claim 1, wherein, The refrigerant circuit comprises a first heat exchanger, a first inlet of the first heat exchanger being connected to an outlet of the compressor through the second valve, a first outlet of the first heat exchanger being connected to an inlet of the compressor, a second inlet of the first heat exchanger being connected to an outlet of a first water pump of the electric vehicle cooling circuit, and a second outlet of the first heat exchanger being connected to an interface of a multi-way valve of the electric vehicle cooling circuit, the first heat exchanger being used for circulating the refrigerant in the refrigerant circuit and the cooling liquid of the cooling circuit and exchanging heat with each other, and the heat management control method further comprising: At the first time, the opening degree of the first water pump is controlled to be less than a first water pump opening degree threshold.

3. The thermal management control method of claim 2, wherein, The refrigerant circuit further comprises an evaporator, a third valve, a fourth valve, and a first pressure sensor, an outlet of the compressor being connected to an inlet of the first valve and an inlet of the second valve through the first pressure sensor respectively, the first pressure sensor being used for measuring the compressed refrigerant pressure output by the compressor, an inlet of the evaporator being connected to an outlet of the condenser and the first outlet of the first heat exchanger through the third valve and circulating the compressed refrigerant, an outlet of the evaporator being connected to an inlet of the compressor, the evaporator being used for heating the interior of the electric vehicle, an inlet of the fourth valve being connected to the outlet of the condenser and the first outlet of the first heat exchanger and circulating the compressed refrigerant, an outlet of the fourth valve being connected to an inlet of the compressor, the third valve and the fourth valve being used for controlling the flow of the compressed refrigerant, and the heat management control method further comprising: At a second time after the first time, if the air outlet flow rate of the air conditioner changes by more than or equal to a first air outlet flow rate threshold and the pressure change value of the first pressure sensor is greater than or equal to a first pressure threshold, the third valve opening degree is controlled to decrease to a third preset valve opening degree, and the fourth valve opening degree is controlled to increase to a fourth preset valve opening degree.

4. The thermal management control method of claim 3, wherein, The refrigerant circuit further comprises a second heat exchanger, a first inlet of the second heat exchanger is connected to an outlet of the fourth valve, a first outlet of the second heat exchanger is connected to an inlet of the compressor, a second inlet of the second heat exchanger is 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 connected to another interface of the multi-way valve, the second heat exchanger is used for circulating the refrigerant in the refrigerant circuit and the coolant of the cooling circuit and exchanging heat with each other, and the thermal management control method further comprises: At the second time, the opening degree of the second water pump is controlled to be less than a second water pump opening degree threshold.

5. The thermal management control method of claim 3, wherein, The thermal management control method further comprises: At a third time after the second time, if the air outlet flow rate of the air conditioner changes by less than the first air outlet flow rate threshold and the pressure change value of the first pressure sensor is less than the first pressure threshold, the first valve, the second valve, the third valve and the fourth valve are controlled to keep the valve opening degree change less than a first opening degree change value.

6. The thermal management control method of any one of claims 1-5, wherein, The refrigerant circuit further comprises a fifth valve, the fifth valve is connected between the inlet and the outlet of the compressor, and the fifth valve is used for controlling the circulation of the compressed refrigerant from the outlet to the inlet of the compressor, and the thermal management control method further comprises: At a fourth time before the first time, if the change value of the hot air volume of the air conditioner switch of the electric vehicle is greater than a first air volume change threshold, the compressor is controlled to start and work at a first rotating speed; The fifth valve opening degree is controlled to increase to a fifth preset valve opening degree, and the first valve opening degree is controlled to increase to a sixth preset valve opening degree, the fifth preset valve opening degree is greater than the sixth preset valve opening degree, and the sixth preset valve opening degree is greater than the first valve preset opening degree.

7. The thermal management control method of claim 6, wherein, The refrigerant circuit further comprises an air conditioner box damper, the air conditioner box damper is arranged on the same side of the condenser and the evaporator, the air conditioner box damper is used for guiding the air blowing to the condenser and the evaporator, and the thermal management control method further comprises: Before the first time after the fourth time, the air conditioner box damper of the air conditioner is controlled to be in an intermediate position towards the evaporator.

8. The thermal management control method of claim 5, wherein, The thermal management control method further comprises: At a fifth time after the third time, if the change value of the hot air volume of the air conditioner switch is greater than a second air volume change threshold, the third valve opening degree is controlled to increase to a seventh preset valve opening degree, and the fourth valve opening degree is controlled to decrease to an eighth preset valve opening degree.

9. The thermal management control method of claim 8, wherein, The thermal management control method further comprises: at a sixth time after the fifth time, if the air conditioner's air flow rate changes greater than or equal to a second air flow rate threshold and the first pressure sensor's pressure change value is greater than or equal to a second pressure threshold, control the first valve opening to increase to a ninth preset valve opening and the second valve opening to decrease to a tenth preset valve opening.

10. The thermal management control method of claim 9, wherein, The thermal management control method further comprises: at a seventh time after the sixth time, if the air conditioner's air flow rate changes greater than or equal to the second air flow rate threshold and the first pressure sensor's pressure change value is greater than or equal to the second pressure threshold, control the second water pump's opening to be greater than a third water pump opening threshold.

11. The thermal management control method of claim 10, wherein, The thermal management control method further comprises: at the seventh time, control the first water pump's opening to be greater than a fourth water pump opening threshold.

12. The thermal management control method according to claim 10 or 11, characterized by, The thermal management control method further comprises: at the seventh time, control the compressor to operate at a second rotation speed, the second rotation speed being less than the first rotation speed.

13. The thermal management control method according to claim 10 or 11, characterized by, The thermal management control method further comprises: at an eighth time after the seventh time, if the air conditioner's air flow rate changes less than the second air flow rate threshold and the first pressure sensor's pressure change value is less than the second pressure threshold, control the first valve, the second valve, the third valve and the fourth valve to maintain valve openings less than a second opening change value.

14. The thermal management control method according to claim 10 or 11, characterized by, The thermal management control method further comprises: before the fifth time after the third time, control the air conditioner's air conditioner box damper to be at a middle position towards the condenser.

15. An electric vehicle characterized by comprising: The electric vehicle employs the thermal management control method of any one of claims 1-14 for in-vehicle temperature regulation.

Images