JP2024073319A - Vehicle Air Conditioning Systems - Google Patents

Abstract

An object of the present invention is to provide a vehicle air conditioning system that efficiently uses waste heat for air conditioning while suppressing deterioration of power consumption.
[Solution] There is provided an air conditioning system for a vehicle having an air conditioning circuit including a condenser, an expansion valve, an evaporator, and a compressor, and through which a refrigerant circulates. The air conditioning system for a vehicle has an electric powertrain and a battery electrically connected to the electric powertrain, and is provided with a coolant circuit through which coolant for cooling the electric powertrain and the battery circulates. In addition, a condenser is disposed on the coolant circuit so as to exchange heat between the refrigerant circulating through the air conditioning circuit and the coolant circulating through the coolant circuit.
[Selected figure] Figure 2

Description

The present invention relates to a vehicle air conditioning system.

In electric vehicles, when air conditioning (cooling) is in use, it is necessary to dissipate heat from the refrigerant through the condenser to the outside air. However, when dissipating heat from the refrigerant by operating a fan or opening a grill shutter to allow the airflow from the vehicle's travel to hit the condenser, there is a risk that the vehicle's electric fuel economy will worsen due to the power consumption required to operate the fan and the deterioration of aerodynamics.

Patent Document 1 discloses a vehicle thermal management system in which the condenser is water-cooled. In this vehicle thermal management system, the condenser is installed in the cooling water passage for the battery, and heat from the condenser is stored in the battery via the cooling water passage, thereby dissipating heat from the refrigerant. This reduces the power consumption required to operate the fan.

US2019/0070924 A1

However, when the temperature inside the vehicle is high and the load of the air conditioning (cooling) is high, the amount of heat dissipated from the condenser increases. When the amount of heat dissipated from the condenser is large, in the vehicle thermal management system described in Patent Document 1, the temperature of the cooling water in the battery cooling water passage increases. As a result, the battery temperature rises and the heat storage time decreases, which may result in insufficient heat dissipation or may affect the reliability of the battery itself due to the temperature rise.

The present invention has been made in consideration of the above problems, and aims to provide a vehicle air conditioning system that can efficiently waste heat from air conditioning while suppressing deterioration of electricity consumption.

According to one aspect of the present invention, there is provided an air conditioning system for a vehicle having a condenser, an expansion valve, an evaporator, and a compressor, and an air conditioning circuit through which a refrigerant circulates. The air conditioning system for a vehicle has an electric powertrain and a battery electrically connected to the electric powertrain, and is provided with a coolant circuit through which coolant for cooling the electric powertrain and the battery circulates. The condenser is disposed on the coolant circuit so as to exchange heat between the refrigerant circulating in the air conditioning circuit and the coolant circulating in the coolant circuit.

According to the present invention, the condenser is disposed on the cooling water circuit through which the cooling water for cooling the electric powertrain and the battery circulates, and in the condenser, heat is exchanged between the refrigerant circulating in the air conditioning circuit and the cooling water circulating in the cooling water circuit. Therefore, the heat of the refrigerant dissipated from the condenser can be stored in the electric powertrain and the battery via the cooling water circuit. This makes it possible to suppress the need to operate the fan or open the grille shutter to waste heat, and suppresses deterioration of the vehicle's electric fuel efficiency.

FIG. 1 is a schematic diagram of a vehicle air conditioning system according to the present embodiment. FIG. 2 is a circuit diagram of the vehicle air conditioning system in a state where the radiator circuit is separated. FIG. 3 is a circuit diagram of the vehicle air conditioning system with the radiator circuit connected. FIG. 4 is a flowchart illustrating the waste heat control of the refrigerant according to this embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

[Embodiment]
Fig. 1 is a schematic diagram of a vehicle air conditioning system (hereinafter, also referred to as an air conditioning system) 100 according to an embodiment of the present invention. The air conditioning system 100 is mainly installed in an electric vehicle or the like. As shown in Fig. 1, the air conditioning system 100 includes an air conditioning circuit 10 through which a refrigerant circulates, a coolant circuit 20 through which coolant for cooling an electric powertrain (ePT) 21 and a battery 22 circulates, a radiator circuit 30, and a controller 40.

The air conditioning circuit 10 is a circuit through which the refrigerant used for air conditioning (cooling) circulates, and functions as an air conditioning heat pump. A compressor 11, a condenser 12, a first expansion valve 13, and an evaporator 14 are provided in this order on the air conditioning circuit 10 in the direction of refrigerant flow. In addition, a second expansion valve 15 and a heat exchanger (chiller) 16 are provided in series in this order in parallel with the first expansion valve 13 and the evaporator 14.

The compressor 11 is, for example, an electric compressor that compresses the refrigerant (gas) flowing through the air conditioning circuit 10 and outputs it at high temperature and high pressure.

The condenser 12 condenses and liquefies the refrigerant (gas) compressed to high temperature and pressure by the compressor 11. The condenser 12 is provided on the air conditioning circuit 10 and on the cooling water circuit 20 described below, and in the condenser 12, heat is exchanged between the refrigerant circulating in the air conditioning circuit 10 and the cooling water circulating in the cooling water circuit 20. In other words, the condenser 12 dissipates the heat of the refrigerant to the cooling water circuit 20.

The first expansion valve 13 rapidly expands the refrigerant flowing through the air conditioning circuit 10 by passing it through tiny holes, resulting in low temperature and pressure. The opening of the first expansion valve 13 is controlled by the controller 40, which will be described later.

The evaporator 14 evaporates the refrigerant flowing through the air conditioning circuit 10. The evaporated refrigerant is sucked back into the compressor 11.

The second expansion valve 15 is arranged in parallel with the first expansion valve 13 and the evaporator 14, and expands the refrigerant flowing through the air conditioning circuit 10 rapidly by passing it through a small hole, making it low-temperature and low-pressure, and sending it to the heat exchanger 16. The opening degree of the second expansion valve 15 is controlled by the controller 40 described below.

The heat exchanger (chiller) 16 is arranged in parallel with the first expansion valve 13 and the evaporator 14, and in series with the second expansion valve 15 downstream of the second expansion valve 15. The heat exchanger 16 is also provided on the air conditioning circuit 10 and on the cooling water circuit 20 described later, and in the heat exchanger 16, the heat of the cooling water circulating in the cooling water circuit 20 is exchanged with the heat of the low-temperature, low-pressure refrigerant in the air conditioning circuit 10. That is, the heat exchanger 16 cools the cooling water in the cooling water circuit 20. The amount of refrigerant flowing to the evaporator 14 side and the amount of refrigerant flowing to the heat exchanger 16 side are controlled by adjusting the opening degree of the first expansion valve 13 and the second expansion valve 15. When the second expansion valve 15 is completely closed, the refrigerant does not flow to the heat exchanger 16 side, but only to the evaporator 14 side.

The cooling water circuit 20 is a circuit through which the cooling water that cools the electric powertrain 21 and the battery 22 circulates. The electric powertrain 21 and the battery 22 are arranged on the cooling water circuit 20, and the condenser 12 is arranged on the cooling water circuit 20 between the electric powertrain 21 and the battery 22 and downstream of the battery 22 in the flow direction of the cooling water. The cooling water circuit 20 also has a branch path 201 that branches from the upstream side of the battery 22 between the electric powertrain 21 and the battery 22, and a branch path 202 that branches from the downstream side of the battery 22 between the battery 22 and the condenser 12. The branch path 201 connects from the upstream side to the downstream side of the battery 22, and the branch path 202 connects from the downstream side to the upstream side of the battery 22. A heat exchanger 16 is also arranged on the branch path 202.

The cooling water circuit 20 also includes first to third switching valves 23, 24, and 25. The first switching valve 23 is disposed between the condenser 12 and the electric power train 21. The second switching valve 24 is disposed between the battery 22 and the condenser 12, and at a location where the branch passage 201 connects to the cooling water circuit 20 downstream of the battery 22. The third switching valve 25 is disposed between the electric power train 21 and the battery 22, and at a location where the branch passage 202 connects to the cooling water circuit 20 upstream of the battery 22. The operation of the switching valves 23, 24, and 25 is controlled by a controller 40, which will be described later.

The electric powertrain 21 is disposed on the cooling water circuit 20 between the condenser 12 and the battery 22, and includes a drive motor and an inverter (not shown). The drive motor is, for example, a three-phase motor, and is an electric motor that drives the drive wheels of the vehicle. The inverter is electrically connected to the drive motor, and drives the drive motor by converting DC power output by the battery 22 (described later) into AC power and supplying it to the drive motor. When the drive motor rotates in response to the drive wheels, the inverter converts the regenerative AC power generated by the drive motor into DC power and inputs it to the battery 22, thereby charging the battery 22. The electric powertrain 21 is provided with an electric powertrain temperature sensor (ePT temperature sensor) that detects the temperature of the electric powertrain 21. The temperature of the electric powertrain 21 (ePT temperature) detected by the ePT temperature sensor is transmitted to the controller 40 (described later).

The electric powertrain 21 is cooled by the coolant flowing through the coolant circuit 20, or stores the heat of the refrigerant that is wasted into the coolant by the condenser 12. Details of the refrigerant waste heat control will be described later.

The battery 22 is disposed on the cooling water circuit 20 between the electric powertrain 21 and the condenser 12. The battery 22 is a high-power battery that is electrically connected to the electric powertrain 21 and supplies driving power to the drive motor via the inverter of the electric powertrain 21. The drive motor is driven to rotate by the power supplied from the battery 22, and the vehicle runs by the power of the drive motor. The battery 22 is provided with a battery temperature sensor (BT temperature sensor) that detects the temperature of the battery 22. In addition, a battery current sensor (BT current sensor) (not shown) that detects the current value of the battery 22 is provided on the wiring that electrically connects the electric powertrain 21 and the battery 22. The temperature (BT temperature) of the battery 22 detected by the BT temperature sensor and the current value (BT current value) of the battery 22 detected by the BT current sensor are transmitted to the controller 40 described later.

When the BT temperature is high, the battery 22 is cooled by the coolant flowing through the coolant circuit 20, and when the BT temperature is low, the battery 22 stores the heat of the refrigerant that is wasted into the coolant by the condenser 12. Details of the refrigerant waste heat control will be described later.

As described above, the condenser 12 is provided on the air conditioning circuit 10 and on the coolant circuit 20, and is disposed on the coolant circuit 20 between the electric powertrain 21 and the battery 22 and downstream of the battery 22 in the direction of coolant flow. As described above, in the condenser 12, heat is exchanged between the heat of the refrigerant circulating in the air conditioning circuit 10 and the heat of the coolant circulating in the coolant circuit 20.

As described above, the heat exchanger (chiller) 16 is provided on the air conditioning circuit 10 and on the coolant circuit 20, and is disposed on the branch path 202 that branches off from the downstream side of the battery 22 between the battery 22 and the condenser 12 on the coolant circuit 20. The heat of the coolant flowing through the branch path 202 is exchanged in the heat exchanger 16 with the heat of the low-temperature, low-pressure refrigerant in the air conditioning circuit 10. This cools the coolant in the coolant circuit 20.

The first switching valve 23 is a three-way valve that can connect and disconnect the cooling water circuit 20 and the radiator circuit 30 described later. The first switching valve 23 is provided on the cooling water circuit 20 between the condenser 12 and the electric powertrain 21. When the radiator circuit 30 is connected, the first switching valve 23 mixes the cooling water flowing from the cooling water circuit 20 on the condenser 12 side and the electric powertrain 21 side and flows it to the radiator circuit 30. When the radiator circuit 30 is disconnected, the cooling water flowing from the cooling water circuit 20 on the condenser 12 side flows through the first switching valve 23 to the cooling water circuit 20 on the electric powertrain 21 side (see FIG. 3). Note that a cooling water temperature sensor (not shown) that detects the temperature of the cooling water flowing through the cooling water circuit 20 is provided between the condenser 12 and the first switching valve 23. The cooling water temperature detected by the cooling water temperature sensor is transmitted to the controller 40 described later.

The second switching valve 24 is a three-way valve disposed between the battery 22 and the condenser 12, and at a location where the branch path 201 and the cooling water circuit 20 downstream of the battery 22 are connected. The second switching valve 24 is configured to be able to connect or disconnect the branch path 201, and is also configured to be able to adjust the flow rate of the cooling water flowing through the branch path 201. When the branch path 201 is connected, the second switching valve mixes the cooling water flowing in from the branch path 201 and the cooling water flowing in from the cooling water circuit 20 on the battery 22 side, and flows the mixture into the cooling water circuit 20 on the condenser 12 side.

The third switching valve 25 is a three-way valve disposed between the electric powertrain 21 and the battery 22, and at a location where the branch passage 202 in which the heat exchanger 16 is provided is connected to the cooling water circuit 20 upstream of the battery 22. The third switching valve 25 is configured to be able to connect or disconnect the branch passage 202. When the branch passage 202 is connected, the third switching valve 25 mixes the cooling water flowing from the cooling water circuit 20 on the electric powertrain 21 side with the cooling water flowing from the branch passage 202, and flows it to the cooling water circuit 20 on the battery 22 side. When the branch passage 202 is disconnected, the cooling water flowing through the cooling water circuit 20 on the electric powertrain 21 side flows through the third switching valve 25 to the cooling water circuit 20 on the battery 22 side (see Figures 2 and 3). The third switching valve 25 is configured to be able to adjust the flow rate of the cooling water flowing from the cooling water circuit 20 on the electric powertrain 21 side to the cooling water circuit 20 on the battery 22 side. That is, the flow rate of the cooling water flowing through the branch path 201 and the flow rate of the cooling water flowing through the cooling water circuit 20 on the battery 22 side are controlled by the operation of the second switching valve 24 and the third switching valve 25.

An electric heater 26 is disposed on the cooling water circuit 20 between the third switching valve 25 and the battery 22. When the battery 22 is warmed up, the electric heater 26 operates to warm up the battery 22. An electric water pump 27 is disposed on the cooling water circuit 20 between the electric heater 26 and the battery 22 to send the cooling water in the cooling water circuit 20 to the battery 22.

The radiator circuit 30 is a circuit in which the radiator 31 is arranged, and is configured to be connectable between the condenser 12 and the electric powertrain 21, and between the electric powertrain 21 and the branch point of the branch path 201. As described above, whether the radiator circuit 30 is connected to or disconnected from the coolant circuit 20 is controlled by the first switching valve 23.

The radiator 31 is provided on the radiator circuit 30, and cools the coolant flowing through the radiator circuit 30 when the radiator circuit 30 is connected to the coolant circuit 20. A fan 32 for the radiator 31 is provided near the radiator 31, and the coolant flowing through the radiator circuit 30 can be cooled by operating the fan 32. The radiator 31 is also provided near a grill shutter 33 that introduces wind into the vehicle, and when the grill shutter 33 is opened, the wind hits the radiator 31. This cools the coolant in the radiator circuit 30. That is, the coolant flowing through the radiator circuit 30 can also be cooled by opening the grill shutter 33. The operation of the fan 32 and the opening and closing of the grill shutter 33 are controlled by a controller 40 described later. In addition, an electric water pump 34 is disposed on the radiator circuit 30 downstream of the radiator 31, which sends the cooling water in the radiator circuit 30 to the electric powertrain 21 and the battery 22.

The controller 40 is composed of one or more computers equipped with a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input/output interface (I/O interface). In this embodiment, the controller 40 is programmed to execute waste heat control of the air conditioning refrigerant (hereinafter referred to as refrigerant waste heat control) by appropriately controlling the operation of the first to third switching valves 23, 24, 25, the fan 32, and the grill shutter 33.

The controller 40 also includes a temperature acquisition unit 41, which acquires the temperature of the electric powertrain 21 detected by the ePT temperature sensor, the temperature of the battery 22 detected by the BT temperature sensor, and the coolant temperature detected by the coolant temperature sensor. The vehicle in which the air conditioning system 100 is mounted also includes an interior temperature sensor (not shown), and the temperature acquisition unit 41 acquires the interior temperature from the interior temperature sensor.

The controller 40 also acquires the current value of the battery 22 detected by the BT current sensor, and calculates and acquires the charge capacity (SOC) of the battery 22 based on the current value. The vehicle in which the air conditioning system 100 is mounted is equipped with a speed sensor (not shown), and the controller 40 acquires the vehicle speed from the speed sensor. Furthermore, the controller 40 acquires information on whether the air conditioning (cooling) is on or off (hereinafter referred to as air conditioning on/off information), and the set temperature of the air conditioning.

As described above, when the radiator circuit 30 is connected to the coolant circuit 20, the air conditioning system 100 is configured to be able to dissipate heat from the refrigerant by operating the fan 32 for the radiator 31 or by opening the grill shutter 33.

However, in an electric vehicle, when using air conditioning (cooling), if the heat of the refrigerant is removed from the condenser by operating the fan or opening the grill shutter to allow the airflow from the vehicle to hit the condenser, this may result in a decrease in the vehicle's electricity consumption due to the power consumed by operating the fan and the deterioration of aerodynamics caused by opening the grill shutter.

In contrast, in this embodiment, the condenser 12 is disposed on the cooling water circuit 20 through which the cooling water for cooling the electric power train 21 and the battery 22 circulates, and the air conditioning system 100 is configured so that the heat of the refrigerant circulating in the air conditioning circuit 10 and the heat of the cooling water circulating in the cooling water circuit 20 are exchanged in the condenser 12. As a result, the heat of the refrigerant exchanged with the heat of the cooling water in the cooling water circuit 20 in the condenser 12 can be stored in the electric power train 21 and the battery 22. That is, the heat of the refrigerant can be discarded without using the radiator 31 to the extent that it can be stored in the electric power train 21 and the battery 22. Therefore, it is possible to suppress the operation of the fan 32 or the opening of the grille shutter 33 for discarding heat, and to suppress the deterioration of the electric power consumption of the vehicle. In addition, since heat can be stored not only in the battery 22 but also in the electric power train 21, even when the load of the air conditioning (cooling) is high and the amount of heat released from the condenser 12 is relatively large, sufficient heat can be discarded without using the fan 32 or the grille shutter 33.

Details of refrigerant waste heat control are explained below.

Figures 2 and 3 are circuit diagrams of the air conditioning system 100 when air conditioning (cooling) is in use. Figure 2 is a circuit diagram in a state where the radiator circuit 30 is disconnected from the coolant circuit 20, and Figure 3 is a circuit diagram in a state where the radiator circuit 30 is connected to the coolant circuit 20.

When air conditioning (cooling) is used, whether or not to connect the radiator circuit 30 to the coolant circuit 20 is determined based on the temperature of the battery 22 and the temperature of the electric powertrain 21. For example, when the temperature of the battery 22 is equal to or lower than a first predetermined value (hereinafter also referred to as a first threshold value T _th1 ) and the temperature of the electric powertrain 21 is equal to or lower than a second predetermined value (hereinafter also referred to as a second threshold value T _th2 ), the first switching valve 23 separates the radiator circuit 30 from the coolant circuit 20. The first threshold value T _th1 here is set to, for example, a temperature value at which it can be estimated that the battery 22 is in a state capable of storing a certain amount of heat and that there is little need to cool the battery 22. The second threshold value T _th2 is set to, for example, a temperature value at which it can be estimated that the electric powertrain 21 is in a state capable of storing a certain amount of heat. When the radiator circuit 30 is separated from the coolant circuit 20, the temperature of the battery 22 is equal to or lower than the first threshold value T _th1 , and therefore there is little need to cool the battery 22. Therefore, the third switching valve 25 separates the branch passage 202 from the coolant circuit 20, and separates the heat exchanger 16. In addition, the first expansion valve 13 is closed, and the refrigerant does not flow through the air conditioning circuit 10 on the heat exchanger 16 side.

When the radiator circuit 30 and the coolant circuit 20, and the branch passage 202 and the coolant circuit 20 are separated, as shown in FIG. 2, the coolant flowing through the coolant circuit 20 circulates from the condenser 12 to the electric powertrain 21 and the battery 22 in that order. Therefore, the heat of the refrigerant exchanged with the coolant in the coolant circuit 20 in the condenser 12 is first stored in the electric powertrain 21, and then stored in the battery 22 arranged downstream of the electric powertrain 21. In this way, when the waste heat of the refrigerant can be sufficiently stored by the battery 22 and the electric powertrain 21, the radiator 31 is separated and the fan 32 and the grille shutter 33 are not operated, so that power consumption and aerodynamic deterioration can be suppressed and electricity consumption can be improved. In addition, by disposing the condenser 12 between the electric powertrain 21 and the battery 22 and downstream of the battery 22, and first storing the heat of the refrigerant in the electric powertrain 21, it is possible to suppress the temperature rise of the battery 22 and suppress the influence on the reliability of the battery 22. In addition, downstream of the electric powertrain 21, the amount of cooling water to be flowed to the shunt 201 side or the battery 22 side is determined based on the temperature of the electric powertrain 21 and the temperature of the battery 22. For example, when the electric powertrain 21 can store most of the heat of the refrigerant, or when the temperature of the battery 22 is relatively high and the amount of heat that can be stored in the battery 22 is small, the second switching valve 24 causes a large amount of cooling water to flow to the shunt 201 side.

On the other hand, when air conditioning (cooling) is in use, for example, when the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 and the temperature of the electric powertrain 21 is higher than the second threshold value _Tth2 , the first switching valve 23 connects the radiator circuit 30 and the coolant circuit 20 as shown in Fig. 3. As a result, the coolant in the radiator circuit 30 is cooled by the operation of the radiator 31 fan 32 and the grill shutter 33 installed near the radiator 31. That is, if the radiator circuit 30 and the coolant circuit 20 are separated when the temperature of the electric powertrain 21 is higher than the second threshold value _Tth2 , the heat of the refrigerant cannot be sufficiently stored by the electric powertrain 21 and the battery 22, or the heat is stored intensively in the battery 22, causing a large temperature rise in the battery 22, which may affect the reliability of the battery 22. Therefore, the heat of the refrigerant is dissipated by using the radiator 31. In this case, since the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 , there is little need to cool the battery 22, and the third switching valve 25 separates the branch passage 202 from the coolant circuit 20 and separates the heat exchanger 16. In addition, the expansion valve 13 is closed, and the refrigerant does not flow through the air conditioning circuit 10 on the heat exchanger 16 side.

When the radiator circuit 30 and the cooling water circuit 20 are connected, as shown in FIG. 3, the cooling water flowing through the cooling water circuit 20 is supplied from the condenser 12 to the radiator circuit 30 via the first switching valve 23, and the cooling water flowing through the radiator circuit 30 is cooled in the radiator 31.

The cooling water in the radiator circuit 30 that has passed through the radiator 31 is again supplied to the cooling water circuit 20, where it is divided into a flow path toward the electric powertrain 21 and a flow path toward the battery 22. The cooling water flowing on the electric powertrain 21 side cools the electric powertrain 21, and is mixed with the cooling water downstream of the condenser 12 in the first changeover valve 23 and is again supplied to the radiator circuit 30. The cooling water in the cooling water circuit 20 that is directed toward the battery 22 is further divided into a branch flow path 201 and a flow path that passes through the battery 22, and the divided cooling water is again mixed in the second changeover valve 24. How much of the cooling water that has passed through the radiator 31 should flow through the flow path that passes through the electric powertrain 21, the branch flow path 201, or the flow path that passes through the battery 22 is determined based on the temperature of the electric powertrain 21 and the temperature of the battery 22, and is controlled by the operation of the first to third switching valves 23, 24, and 25. For example, when the temperature of the electric powertrain 21 is high and cooling is required, more cooling water is supplied to the flow path that passes through the electric powertrain 21.

When air conditioning (cooling) is not used and the temperature of the battery 22 is higher than the first threshold T _th1 , the radiator circuit 30 and the coolant circuit 20 are connected, and the coolant in the coolant circuit 20 is cooled in the radiator 31, and the heat of the refrigerant is discarded. The cooled coolant cools the electric powertrain 21 and the battery 22. When the coolant cooled in the radiator 31 cannot sufficiently cool the battery 22, a branch passage 202 is connected to the coolant circuit 20, and the coolant is further cooled by a heat exchanger (chiller) 16 provided on the branch passage 202. Hereinafter, the above control when air conditioning (cooling) is not used and the temperature of the battery 22 is higher than the first threshold T _th1 is referred to as normal control. In normal control, the heat of the refrigerant is discarded by the radiator 31, the electric powertrain 21 and the battery 22 are cooled, and the battery 22 is further cooled by the heat exchanger (chiller) 16 as necessary.

When using heating, the circuit connections are the same as in normal control, but when warming up the battery 22, the electric heater 26 operates to warm up the battery 22. Note that FIG. 1 is a circuit diagram of the air conditioning system 100 when using normal control or heating.

As described above, when air conditioning (cooling) is in use, whether or not to connect the radiator circuit 30 to the coolant circuit 20 is determined based on the temperature of the battery 22 and the temperature of the electric powertrain 21.

In this embodiment, when the difference between the vehicle interior temperature and the air conditioning set temperature is greater than a third predetermined value (hereinafter, also referred to as a third threshold value ΔT _th3 ), the radiator circuit 30 and the coolant circuit 20 are connected regardless of the temperatures of the electric powertrain 21 and the battery 22. When the difference between the vehicle interior temperature and the air conditioning set temperature is large, the load of the compressor 11 on the air conditioning circuit 10 needs to be increased. In this case, the heat of the refrigerant radiated from the condenser 12 increases. Therefore, when the difference between the vehicle interior temperature and the air conditioning set temperature is large, the amount of waste heat of the refrigerant may exceed the amount of heat that can be stored by the electric powertrain 21 and the battery 22. Therefore, when the difference between the vehicle interior temperature and the air conditioning set temperature is greater than the third threshold value ΔT _th3 , the radiator circuit 30 and the coolant circuit 20 are connected, and the heat of the refrigerant is discharged using the radiator 31 (fan 32, grill shutter 33). The third threshold value ΔT _th3 here is set, for example, to a maximum value of the in-vehicle temperature that can be lowered by the amount of heat that can be stored when the electric powertrain 21 and the battery 22 are stopped. In this manner, in this embodiment, when the difference between the in-vehicle temperature and the air conditioning set temperature is larger than the third threshold value ΔT _th3 , the radiator circuit 30 and the coolant circuit 20 are connected. However, this is not necessarily limited to this, and whether or not to connect the radiator circuit 30 to the coolant circuit 20 may be determined based only on the temperature of the battery 22 and the temperature of the electric powertrain 21.

When air conditioning (cooling) is in use and the radiator circuit 30 and the coolant circuit 20 are connected, whether or not to open the grill shutter 33 is determined based on the vehicle speed of the vehicle in which the air conditioning system 100 is mounted, the vehicle interior temperature, and the temperature of the coolant in the coolant circuit 20. For example, the grill shutter 33 is opened when the difference between the vehicle interior temperature and the air conditioning set temperature is equal to or greater than a third threshold value ΔT _th3 , when the vehicle speed is smaller than a predetermined value (hereinafter also referred to as threshold value V _th ), or when the vehicle speed is equal to or greater than threshold value V _th and the temperature of the coolant flowing through the coolant circuit 20 is greater than predetermined threshold value T _th .

When the difference between the vehicle interior temperature and the air conditioning set temperature is large, as described above, it is predicted that the load on the compressor 11 in the air conditioning circuit 10 will be large. This will increase the heat of the refrigerant radiated from the condenser 12. Therefore, when the difference between the vehicle interior temperature and the air conditioning set temperature is equal to or greater than the third threshold value ΔT _th3 , the grill shutter 33 is opened to dissipate the heat of the refrigerant.

When the vehicle speed is low, opening the grille shutter 33 does not cause much aerodynamic deterioration. Therefore, when the vehicle speed is lower than the threshold value _Vth , the grille shutter 33 is opened to dissipate heat from the refrigerant. The threshold value _Vth here is set, for example, to a value that causes almost no deterioration in power consumption due to the deterioration in aerodynamics caused when the grille shutter 33 is opened.

Furthermore, even if the vehicle speed is equal to or higher than the threshold value _Vth , if the temperature of the coolant flowing through the coolant circuit 20 is high, it is estimated that the amount of heat dissipated from the refrigerant in the condenser 12 is relatively large, and there is a high need to dissipate the heat of the refrigerant. Therefore, if the vehicle speed is equal to or higher than the threshold value _Vth and the temperature of the coolant flowing through the coolant circuit 20 is higher than a predetermined threshold value _Tth , the grill shutter 33 is opened to dissipate the heat of the refrigerant. Here, the predetermined threshold value _Tth is set to a temperature that can sufficiently cool the electric powertrain 21, for example.

In addition, when the vehicle speed is high, the aerodynamic deterioration caused by opening the grille shutter 33 also becomes large. Therefore, in this embodiment, when the vehicle speed is equal to or higher than the threshold _Vth and the SOC of the battery 22 is higher than a predetermined value (hereinafter referred to as the threshold _SOCth ), the coolant temperature threshold _Tth for determining whether or not to open the grille shutter 33 is set to a fifth predetermined value (hereinafter referred to as the fifth threshold _Tth5 ) which is larger than when the SOC of the battery 22 is equal to or _lower than the threshold SOCth. As a result, when the SOC of the battery 22 is relatively high, the number of situations in which the grille shutter 33 is closed increases, and it is possible to suppress deterioration of the electric power consumption due to deterioration of the aerodynamics. On the other hand, when the SOC of the battery 22 is low (for example, 30% or less), the electric resistance value of the cell becomes large, and heat generation of the battery 22 becomes large. Therefore, when the vehicle speed is equal to or higher than the threshold _Vth and the SOC of the battery 22 is equal to or lower than the threshold _SOCth , the threshold _Tth is set to a sixth predetermined value (hereinafter referred to as the sixth threshold _{Tth6) that is lower than the fifth threshold Tth5 ,} compared to when the SOC of the battery 22 is higher than the threshold _SOCth . This increases the number of situations in which the grill shutter 33 is opened, making it possible to respond to the cooling demand for the battery 22.

When the radiator circuit 30 and the coolant circuit 20 are connected during air conditioning (cooling), whether or not to operate the fan 32 for the radiator 31 is determined based on the temperature of the coolant in the coolant circuit 20. When the radiator circuit 30 and the coolant circuit 20 are connected, the grille shutter 33 is first opened based on the vehicle speed, the vehicle interior temperature, and the temperature of the coolant in the coolant circuit 20, but when the driving wind alone is not sufficient to dissipate heat from the refrigerant, the fan 32 for the radiator 31 is operated. Specifically, when the temperature of the coolant in the coolant circuit 20 is greater than a fourth predetermined value (hereinafter also referred to as a fourth threshold value T _th4 ), the fan 32 is operated. The fourth threshold value T _th4 here is a value greater than the opening/closing threshold value (temperature threshold value) T _th of the grille shutter 33, and is set to a temperature value at which the heat of the refrigerant cannot be sufficiently dissipated even if the grille shutter 33 is opened when the vehicle is traveling at a speed approximately equal to the legal speed limit, for example. When the temperature of the coolant is higher than the fourth threshold value _Tth4 , the heat of the refrigerant dissipated in the condenser 12 is large, so that the coolant in the radiator circuit 30 (and the coolant circuit 20) is further cooled by operating the fan 32. This allows the radiator 31 to sufficiently dissipate the heat of the refrigerant.

Figure 4 is a flowchart explaining the waste heat control of the refrigerant in this embodiment. All of the following controls are repeatedly executed at predetermined time intervals by the controller 40. The controller 40 appropriately acquires the temperature of the electric powertrain 21 (ePT temperature), the temperature of the battery 22 (BT temperature), the coolant temperature, the vehicle interior temperature, the SOC of the battery 22, the vehicle speed, the on/off information of the air conditioning, and the set temperature of the air conditioning.

When the vehicle's vehicle system is turned on, such as by turning on the ignition switch, refrigerant waste heat control begins.

In step S101, the controller 40 determines whether the air conditioning (cooling) is on. If the air conditioning is on, the controller 40 executes the process of step S102. On the other hand, if the air conditioning is off, the controller 40 executes normal control.

In step S102, the controller 40 determines whether or not the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 . If the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 , the controller 40 executes the process of step S103. On the other hand, if the temperature of the battery 22 is higher than the first threshold value _Tth1 , cooling of the battery 22 is necessary, and the controller 40 executes normal control.

In step S103, the controller 40 determines whether the difference between the in-vehicle temperature and the air-conditioning set temperature is greater than a third threshold value ΔT _th3 . If the difference between the in-vehicle temperature and the air-conditioning set temperature is greater than the third threshold value ΔT _th3 (i.e., the load on the compressor 11 is large), the controller 40 executes the process of step S104. On the other hand, if the difference between the in-vehicle temperature and the air-conditioning set temperature is equal to or smaller than the third threshold value ΔT _th3 (i.e., the load on the compressor 11 is small), the controller 40 executes the process of step S110.

In step S104, the controller 40 operates the first switching valve 23 to connect the cooling water circuit 20 and the radiator circuit 30.

In step S105, the controller 40 controls the grill shutter (G/S) 33 to open. This allows the radiator 31 to be exposed to the wind, cooling the coolant in the radiator circuit 30, and dissipating heat from the refrigerant in the radiator 31.

In step S106, the controller 40 determines whether the coolant temperature in the coolant circuit 20 is equal to or lower than a fourth threshold value _Tth4 . If the coolant temperature is equal to or lower than the fourth threshold value _Tth4 , the controller 40 executes the process of step S107. On the other hand, if the coolant temperature is higher than the fourth threshold value _Tth4 , the controller 40 executes the process of step S108.

In step S107, the controller 40 stops and does not operate the fan 32 for the radiator 31. That is, when the coolant temperature is equal to or lower than the fourth threshold value _Tth4 , the heat of the refrigerant radiated from the condenser 12 is not so large, so the fan 32 is not operated and the grill shutter 33 is opened to dissipate the heat of the refrigerant. This reduces the power consumption required to operate the fan 32, improving power efficiency.

When the coolant temperature is higher than the fourth threshold value _Tth4 , the controller 40 operates the fan 32 for the radiator 31 in step S108. As a result, the coolant flowing through the radiator circuit 30 (and the coolant circuit 20) is further cooled in the radiator 31, and the heat of the refrigerant is dissipated. That is, when the coolant temperature is higher than the fourth threshold value _Tth4 , the heat of the refrigerant radiated from the condenser 12 is large, so the grill shutter 33 is opened and the fan 32 is operated to dissipate the heat of the refrigerant.

In step S103, if the difference between the in-vehicle temperature and the air conditioning set temperature is equal to or less than the third threshold value ΔT _th3 (i.e., if the load on the compressor 11 is small), the controller 40 determines in step S109 whether the temperature of the electric powertrain 21 (ePT temperature) is equal to or less than the second threshold value T _th2 . That is, the controller 40 determines whether heat can be stored in the electric powertrain 21. If the temperature of the electric powertrain 21 is equal to or less than the second threshold value T _th2 , the controller 40 executes the process of step S110. On the other hand, if the temperature of the electric powertrain 21 is greater than the second threshold value T _th2 , the controller 40 executes the process of step S111.

When the temperature of the electric powertrain 21 is equal to or lower than the second threshold value T _th2 , heat can be stored in the electric powertrain 21. Therefore, in step S110, the controller 40 controls the first switching valve 23 to disconnect or not connect the coolant circuit 20 and the radiator circuit 30. In addition, the fan 32 is stopped and does not operate, and the grill shutter 33 is closed. As a result, the radiator 31 is disconnected from the coolant circuit 20, and the heat of the refrigerant radiated from the condenser 12 is stored in the electric powertrain 21 and the battery 22 via the coolant in the coolant circuit 20. In this way, when the electric powertrain 21 and the battery 22 are capable of storing heat, the radiator circuit 30 is disconnected, the fan 32 is not operated, and the grill shutter 33 is closed, thereby suppressing power consumption and aerodynamic deterioration.

When the temperature of the electric powertrain 21 is higher than the second threshold value _Tth2 , almost no heat of the refrigerant can be stored in the electric powertrain 21. Therefore, in step S111, the controller 40 activates the first switching valve 23 to connect the coolant circuit 20 and the radiator circuit 30.

In step S112, the controller 40 judges whether the vehicle speed is equal to or higher than the threshold value _Vth . If the vehicle speed is equal to or higher than the threshold value _Vth (if the vehicle is driving at high speed), the controller 40 executes the process of step S113. On the other hand, if the vehicle speed is lower than the threshold value _Vth (if the vehicle is driving at low speed or is stopped), the controller 40 executes the process of step S105.

In step S113, the controller 40 determines whether the SOC of the battery 22 is equal to or lower than the threshold SOC _th . If the SOC of the battery 22 is equal to or lower than the threshold SOC _th , the controller 40 executes the processes of steps S114 and S115. If the SOC of the battery 22 is greater than the threshold SOC _th , the controller 40 executes the processes of steps S118 and S119.

In step S114, the controller 40 sets the coolant temperature threshold _Tth for determining whether or not to open the grill shutter 33 to a sixth threshold _Tth6 , and in step S115, determines whether or not the temperature of the coolant flowing through the coolant circuit 20 is equal to or lower than the sixth threshold _Tth6 . If the coolant temperature is equal to or lower than the sixth threshold _Tth6 , the controller 40 executes the process of step S116. On the other hand, if the coolant temperature is higher than the sixth threshold _Tth6 , the controller 40 executes the process of step S117.

When the coolant temperature is equal to or lower than the sixth threshold value _Tth6 , the amount of heat dissipated from the refrigerant in the condenser 12 is small, so in step S116, the controller 40 controls the grill shutter 33 to close.

When the coolant temperature is higher than the sixth threshold value _Tth6 , the amount of heat dissipated from the refrigerant in the condenser 12 is relatively large, so in step S117, the controller 40 controls the grill shutter 33 to open. This allows the radiator 31 to be exposed to the wind generated by running, cooling the coolant in the radiator circuit 30, and dissipating heat from the refrigerant in the radiator 31. Note that in this case as well, the fan 32 is not operated.

In this way, when the SOC of the battery 22 is equal to or lower than the threshold _SOCth , even if the coolant temperature is higher than the sixth threshold _Tth6 , the fan 32 is not operated and the grill shutter 33 is controlled to be open, thereby dissipating heat from the refrigerant. In other words, when the SOC of the battery 22 is low, the fan 32 is not operated and the grill shutter 33 is controlled to dissipate heat, thereby suppressing power consumption of the battery 22.

If the SOC of the battery 22 is greater than the threshold _SOCth in step S113, the controller 40 sets the coolant temperature threshold _Tth for determining whether or not to open the grill shutter 33 to a fifth threshold _Tth5 greater than the sixth threshold _Tth6 in step S118. Also, in step S119, it is determined whether or not the temperature of the coolant flowing through the coolant circuit 20 is equal to or lower than the fifth threshold _Tth5 . If the coolant temperature is equal to or lower than the fifth threshold _Tth5 , the controller 40 executes the process of step S120. On the other hand, if the coolant temperature is greater than the fifth threshold _Tth5 , the controller 40 executes the process of step S121.

When the coolant temperature is equal to or lower than the fifth threshold value _Tth5 , the amount of heat dissipated from the refrigerant in the condenser 12 is small, so in step S120, the controller 40 controls the grill shutter 33 to close.

When the coolant temperature is higher than the fifth threshold value _Tth5 , the amount of heat dissipated from the refrigerant in the condenser 12 is relatively large. Therefore, in step S121, the controller 40 controls the grill shutter 33 to open, and the heat of the refrigerant is dissipated in the radiator 31 by the wind generated by running.

In this way, when the vehicle speed is equal to or higher than the threshold value _Vth , and the SOC of the battery 22 is higher than the threshold value _SOCth , the opening/closing threshold (temperature threshold) _Tth of the grill shutter 33 is set to the fifth threshold value _Tth5 , which is higher than the sixth threshold value _Tth6 , to increase the number of situations where the grill shutter 33 is closed when the SOC of the battery 22 is relatively high. This prevents aerodynamic deterioration caused by opening the grill shutter 33 in situations where the vehicle speed is high. On the other hand, when the SOC of the battery 22, in which the cell's electrical resistance value is high, is equal to or lower than the threshold _value SOCth, the opening/closing threshold (temperature threshold) _Tth of the grill shutter 33 is set to the sixth threshold value _Tth6 , which is lower than the fifth threshold value _Tth5 , to increase the number of situations where the grill shutter 33 is opened. This makes it possible to respond to the cooling request for the battery 22.

The processes of steps S121 to S124 are the same as those of steps S105 to S108. That is, when the grill shutter 33 is controlled to be open in step S121, the controller 40 judges in step S122 whether or not the coolant temperature in the coolant circuit 20 is equal to or lower than the fourth threshold value _Tth4 . If the coolant temperature is equal to or lower than the fourth threshold value _Tth4 , the controller 40 stops the fan 32 in step S123 and does not operate it. On the other hand, if the coolant temperature is higher than the fourth threshold value _Tth4 , the controller 40 operates the fan 32 in step S124 to dissipate heat from the refrigerant. That is, if the coolant temperature is higher than the fourth threshold value _Tth4 , the grill shutter 33 is opened and the fan 32 is operated to dissipate heat from the refrigerant.

In step S112, when the vehicle speed is lower than the threshold value _Vth (when the vehicle is driving at a low speed or is stopped), the controller 40 controls the grill shutter 33 to open, similarly to the case in which the difference between the inside temperature and the set temperature is greater than the third threshold value _Tth3 in step S105. As a result, the radiator 31 is exposed to the wind caused by the vehicle running, the coolant in the radiator circuit 30 is cooled, and the heat of the refrigerant is dissipated in the radiator 31.

In this way, when the vehicle is traveling at low speed or is stopped, opening the grille shutter 33 hardly causes any deterioration in aerodynamics. Therefore, when the vehicle speed is lower than the threshold value _Vth , the grille shutter 33 is opened to dissipate heat from the refrigerant, regardless of the SOC of the battery 22 or the coolant temperature.

When the grill shutter 33 is controlled to be open in step S105, the controller 40 determines in step S106 whether or not the coolant temperature in the coolant circuit 20 is equal to or lower than a fourth threshold value _Tth4 . If the coolant temperature is equal to or lower than the fourth threshold value _Tth4 , the controller 40 stops the fan 32 in step S107 and does not operate it. On the other hand, if the coolant temperature is higher than the fourth threshold value _Tth4 , the controller 40 operates the fan 32 in step S108 to dissipate heat from the refrigerant. That is, if the coolant temperature is higher than the fourth threshold value _Tth4 , the grill shutter 33 is opened and the fan 32 is operated to dissipate heat from the refrigerant.

In this embodiment, the radiator circuit 30 and the coolant circuit 20 are separated when the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 , the temperature of the electric powertrain 21 is equal to or lower than the second threshold value _Tth2 , and the difference between the vehicle interior temperature and the air conditioning set temperature is equal to or lower than the third threshold value _ΔTth3 , but this is not limited to this. That is, regardless of the difference between the vehicle interior temperature and the air conditioning set temperature, the radiator circuit 30 may be controlled to be separated from the coolant circuit 20 when the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 and the temperature of the electric powertrain 21 is equal to or lower than the second threshold value _Tth2 .

The flowchart in FIG. 4 is an example, and the order of judgment for judging whether the difference between various temperatures, vehicle speed, and interior temperature and the air conditioning set temperature is greater than each threshold value is not limited to that described above, and the order of each judgment may be changed as appropriate.

The vehicle air conditioning system 100 of the above embodiment can provide the following advantages:

The air conditioning system 100 includes a coolant circuit 20 through which coolant for cooling the electric power train 21 and the battery 22 circulates, and a condenser 12 is disposed on the coolant circuit 20 so as to exchange heat between the refrigerant circulating in the air conditioning circuit 10 and the coolant circulating in the coolant circuit 20. This allows the heat of the refrigerant exchanged with the heat of the coolant in the coolant circuit 20 in the condenser 12 to be stored in the electric power train 21 and the battery 22. This makes it possible to suppress the operation of the fan 32 for the radiator 31 and the opening of the grille shutter 33 for waste heat, thereby suppressing deterioration of power consumption and aerodynamics. In other words, deterioration of the vehicle's electric power consumption can be suppressed.

In addition, since heat can be stored not only in the battery 22 but also in the electric powertrain 21, even when the air conditioning (cooling) load is high and the amount of heat dissipated from the condenser 12 is relatively large, the heat of the refrigerant can be sufficiently removed without using the fan 32 or grill shutter 33. This makes it possible to suppress deterioration of power consumption and aerodynamics, and to suppress deterioration of the vehicle's electric power consumption. In addition, since the stored heat is not concentrated in the battery 22, the temperature rise of the battery 22 can be suppressed, and the impact on the reliability of the battery 22 can be suppressed.

In the air conditioning system 100, the condenser 12 is disposed on the cooling water circuit 20 between the electric powertrain 21 and the battery 22, and downstream of the battery 22 in the direction of the flow of the cooling water. This allows the heat of the refrigerant dissipated to the cooling water in the cooling water circuit 20 in the condenser 12 to be stored first in the electric powertrain 21, and then in the battery 22. This makes it possible to suppress a rise in the temperature of the battery 22, and to suppress any effects on the reliability of the battery 22.

The air conditioning system 100 includes a radiator circuit 30 in which a radiator 31 is disposed, a first switching valve (switching valve) 23 configured to be able to connect and disconnect the radiator circuit 30 to and from the coolant circuit 20, and a controller 40 that controls the operation of the first switching valve (switching valve) 23. As a result, when the heat of the refrigerant can be stored in the electric power train 21 and the battery 22, the radiator circuit 30 can be disconnected and the heat of the refrigerant can be dissipated without using the radiator 31. On the other hand, when the heat of the refrigerant is greater than the amount of heat that can be stored in the electric power train 21 and the battery 22, the radiator circuit 30 can be connected and the heat of the refrigerant can be dissipated by the radiator 31 as well. Therefore, the number of times the radiator 31 is used can be reduced as much as possible, power consumption and aerodynamic deterioration can be suppressed, and the heat of the refrigerant can be reliably dissipated.

In the air conditioning system 100, when the temperature of the battery 22 is equal to or lower than a first predetermined value (first threshold value T _th1 ) and the temperature of the electric powertrain 21 is equal to or lower than a second predetermined value (second threshold value T _th2 ), the controller 40 controls the first changeover valve (changeover valve) 23 to separate the radiator circuit 30 from the coolant circuit 20, and stores the heat of the refrigerant in the electric powertrain 21 and the battery 22. As a result, when the temperatures of the electric powertrain 21 and the battery 22 are low and the amount of heat that can be stored is large, the heat of the refrigerant is stored in the electric powertrain 21 and the battery 22, and the heat of the refrigerant can be discarded without using the radiator 31. In other words, it is possible to suppress the operation of the fan 32 for the radiator 31 and the opening of the grille shutter 33 for discarding heat, and it is possible to suppress deterioration of power consumption and aerodynamics.

In the air conditioning system 100, when the temperature of the battery 22 is equal to or lower than a first predetermined value (first threshold value T _th1 ) and the temperature of the electric powertrain 21 is higher than a second predetermined value (second threshold value T _th2 ), the controller 40 controls the first switching valve (switching valve) 23 to connect the radiator circuit 30 to the coolant circuit 20, and dissipates heat from the refrigerant using the radiator 31. As a result, when the temperatures of the electric powertrain 21 and the battery 22 are high and the amount of heat that can be stored is small, the heat from the refrigerant is dissipated using the radiator 31. Therefore, the heat from the refrigerant can be reliably dissipated.

The air conditioning system 100 is equipped with a grill shutter 33 that introduces airflow into the vehicle, and the controller 40 controls the opening and closing of the grill shutter 33 based on the vehicle speed, the temperature inside the vehicle, and the temperature of the coolant. In this way, the grill shutter 33 is opened and closed based on the vehicle speed, the temperature inside the vehicle, and the temperature of the coolant, so that the number of times the grill shutter 33 is opened can be reduced as much as possible, and deterioration of aerodynamics can be suppressed.

In the air conditioning system 100, when the temperature of the battery 22 is equal to or lower than a first predetermined value (first threshold T _th1 ), the difference between the vehicle interior temperature and the air conditioning set temperature is equal to or higher than a third predetermined value (third threshold ΔT _th3 ), and the vehicle speed is equal to or higher than a predetermined value (threshold V _th ), the controller 40 controls the first switching valve (switching valve) 23 to connect the radiator circuit 30 to the coolant circuit 20, and controls the grille shutter 33 to open, so that the heat of the refrigerant is dissipated by the radiator 31. In this way, when the difference between the vehicle interior temperature and the air conditioning set temperature is large and it is predicted that the amount of heat of the refrigerant dissipated from the condenser 12 to the coolant will be large, the controller 40 controls the grille shutter 33 to open when the vehicle speed is high. As a result, a strong running wind is introduced into the vehicle, and the cooling capacity for cooling the coolant is increased, so that the frequency of operation of the fan 32 for the radiator 31 can be reduced. Therefore, the power consumption for driving the fan 32 can be reduced, and the deterioration of the power consumption can be suppressed.

In the air conditioning system 100, when the temperature of the battery 22 is equal to or lower than a first predetermined value (first threshold T _th1 ), the difference between the vehicle interior temperature and the air conditioning set temperature is smaller than a third predetermined value (third threshold ΔT _th3 ), and the vehicle speed is smaller than a predetermined value (threshold V _th ), if the temperature of the electric powertrain 21 is equal to or lower than a second predetermined value (second threshold T _th2 ), the controller 40 controls the first changeover valve (changeover valve) 23 to disconnect the radiator circuit 30 from the coolant circuit 20. Also, when the temperature of the electric powertrain 21 is greater than the second predetermined value (second threshold T _th2 ), the controller 40 controls the first changeover valve (changeover valve) 23 to connect the radiator circuit 30 to the coolant circuit 20 and controls the grill shutter 33 to open. That is, when the difference between the vehicle interior temperature and the air conditioning set temperature is large and it is predicted that the amount of heat of the refrigerant dissipated to the coolant from the condenser 12 will be small, if the vehicle speed and the temperature of the electric powertrain 21 are low, the radiator circuit 30 is separated from the coolant circuit 20 and the grill shutter 33 does not open (the grill shutter 33 is controlled to be closed). Therefore, the grill shutter 33 closes more frequently, and the deterioration of aerodynamics can be suppressed.

In the air conditioning system 100, the controller 40 controls the opening and closing of the grill shutter 33 based on the vehicle speed, the vehicle interior temperature, the SOC of the battery 22, and the temperature of the coolant flowing through the coolant circuit 20. This reduces the opening frequency of the grill shutter 33 (increases the closing frequency) when the SOC of the battery 22 is high, thereby suppressing aerodynamic deterioration, and increases the opening frequency of the grill shutter 33 when the SOC is low, which increases the electrical resistance of the cells and the heat generation of the battery 22, to meet the cooling demands of the battery 22.

In the air conditioning system 100, the controller 40 controls the grill shutter 33 to open when the temperature of the battery 22 is equal to or lower than a first predetermined value (first threshold T _th1 ), the difference between the vehicle interior temperature and the air conditioning set temperature is smaller than a third predetermined value (third threshold ΔT _th3 ), and the vehicle speed is equal to or higher than a predetermined value (threshold V _th ), and the temperature of the coolant flowing through the coolant circuit 20 is greater than the predetermined threshold T _th . When the SOC of the battery 22 is greater than the predetermined value (threshold SOC _th ), the predetermined threshold T _th is set to a larger value than when the SOC is equal to or lower than the predetermined value (threshold SOC _th ). In other words, when the vehicle speed is high and the impact on power consumption due to aerodynamic deterioration when the grill shutter 33 is open is large, the opening frequency of the grill shutter 33 is reduced (the closing frequency is increased) when the SOC of the battery 22 is high, and the aerodynamic deterioration is suppressed. On the other hand, when the SOC of the battery 22 is low, causing the electrical resistance of the cells to increase and the heat generated by the battery 22 to increase, the opening frequency of the grille shutter 33 increases, and the cooling requirement for the battery 22 is satisfied.

The waste heat control of the refrigerant described in this embodiment is an example, and is not necessarily limited to this. In other words, any method can be used for waste heat control of the refrigerant, as long as the condenser 12 is configured to be arranged on the coolant circuit 20 so as to exchange heat between the heat of the refrigerant circulating in the air conditioning circuit 10 and the heat of the coolant circulating in the coolant circuit 20.

In addition, in the present embodiment, when the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 and the temperature of the electric powertrain 21 is equal to or lower than the second threshold value _Tth2 , the radiator circuit 30 is disconnected from the coolant circuit 20, but this is not necessarily limited to this. For example, when the temperature of the battery 22 is equal to or lower than the first threshold value _Tth1 and the temperature of the electric powertrain 21 is equal to or lower than the second threshold value _Tth2 , the radiator circuit 30 may be connected to the coolant circuit 20 and the fan 32 may be stopped. In this case as well, the power consumption for operating the fan 32 can be reduced.

Although the embodiments of the present invention have been described above, the above embodiments merely show some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

10, air conditioning circuit, 12, condenser, 20, cooling water circuit, 21, electric power train, 22, battery, 30, radiator circuit, 31, radiator, 32, fan, 33, grill shutter, 40, controller, 100, vehicle air conditioning system

Claims (10)

A vehicle air conditioning system including an air conditioning circuit having a condenser, an expansion valve, an evaporator, and a compressor, and through which a refrigerant circulates,
The vehicle has an electric powertrain and a battery electrically connected to the electric powertrain, and includes a cooling water circuit through which cooling water for cooling the electric powertrain and the battery circulates;
the condenser is disposed on the cooling water circuit so as to exchange heat between the refrigerant circulating through the air conditioning circuit and the cooling water circulating through the cooling water circuit;
Vehicle air conditioning systems. 2. The vehicle air conditioning system according to claim 1,
the condenser is disposed on the cooling water circuit between the electric powertrain and the battery and downstream of the battery in a flow direction of the cooling water.
Vehicle air conditioning systems. 2. The vehicle air conditioning system according to claim 1,
a radiator circuit in which the radiator is disposed;
a switching valve configured to be able to connect and disconnect the radiator circuit to and from the coolant circuit;
A controller for controlling the operation of the switching valve is further provided.
Vehicle air conditioning systems. 4. The vehicle air conditioning system according to claim 3,
the controller has a temperature acquisition unit that acquires temperatures of the battery and the electric powertrain,
when the temperature of the battery is equal to or lower than a first predetermined value and the temperature of the electric powertrain is equal to or lower than a second predetermined value, the controller controls the switching valve to separate the radiator circuit from the coolant circuit, or stops the radiator fan, and stores heat of the refrigerant in the electric powertrain and the battery.
Vehicle air conditioning systems. 4. The vehicle air conditioning system according to claim 3,
the controller has a temperature acquisition unit that acquires temperatures of the battery and the electric powertrain,
When a temperature of the battery is equal to or lower than a first predetermined value and a temperature of the electric powertrain is greater than a second predetermined value, the controller controls the switching valve to connect the radiator circuit to the coolant circuit, and dissipates heat of the refrigerant through the radiator.
Vehicle air conditioning systems. 6. The vehicle air conditioning system according to claim 4,
A grill shutter is further provided to introduce a traveling wind into the vehicle.
The temperature acquisition unit further acquires a temperature inside the vehicle and a temperature of the cooling water,
The controller controls opening and closing of the grill shutter based on a vehicle speed, an interior temperature, and a temperature of the cooling water.
Vehicle air conditioning systems. 7. The vehicle air conditioning system according to claim 6,
the controller controls the switching valve to connect the radiator circuit to the cooling water circuit and controls the grille shutter to open when the temperature of the battery is equal to or lower than a first predetermined value, the difference between the vehicle interior temperature and the air conditioning set temperature is equal to or higher than a third predetermined value, and the vehicle speed is equal to or higher than a predetermined value, thereby dissipating heat of the refrigerant through the radiator.
Vehicle air conditioning systems. 7. The vehicle air conditioning system according to claim 6,
the controller controls the switching valve to disconnect the radiator circuit from the coolant circuit or stops the radiator fan when the temperature of the electric powertrain is equal to or lower than a second predetermined value in the following cases: the temperature of the battery is equal to or lower than a first predetermined value, a difference between an interior temperature and an air conditioning set temperature is smaller than a third predetermined value, and the vehicle speed is smaller than a predetermined value; and controls the switching valve to connect the radiator circuit to the coolant circuit and opens the grill shutter when the temperature of the electric powertrain is greater than the second predetermined value.
Vehicle air conditioning systems. 7. The vehicle air conditioning system according to claim 6,
An SOC acquisition unit that acquires an SOC of the battery,
The controller controls opening and closing of the grill shutter based on a vehicle speed, an in-vehicle temperature, an SOC of the battery, and a temperature of the coolant flowing through the coolant circuit.
Vehicle air conditioning systems. 10. The vehicle air conditioning system according to claim 9,
The controller:
when the temperature of the battery is equal to or lower than a first predetermined value, the difference between the vehicle interior temperature and the air conditioning temperature setting is smaller than a third predetermined value, and the vehicle speed is equal to or higher than a predetermined value, the grill shutter is controlled to open when the temperature of the cooling water flowing through the cooling water circuit is higher than a predetermined threshold value;
When the SOC of the battery is greater than a predetermined value, the predetermined threshold is set to a larger value than when the SOC is equal to or less than the predetermined value.
Vehicle air conditioning systems.