Vehicle thermal management systems

Abstract

This design prevents waste heat from the battery from being absorbed by the drive unit when the drive unit temperature is low, allowing the battery's waste heat to be effectively utilized for heating. [Solution] The thermal management system S comprises the oil coolers FC and RC of the drive unit E, a refrigerant circuit 20, a chiller 30, a first circuit 100 for adjusting the temperature of the battery B, a second circuit 200 for adjusting the oil temperature, a third circuit 300 having a radiator 301, and a fourth circuit 400 connected to the chiller 30. When the oil temperature is low, the first circuit 100 and the fourth circuit 400 are connected, and the second circuit 200 is disconnected. When the oil temperature is high, the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400 are connected.

Description

Technical Field

[0001] The present disclosure relates to a vehicle thermal management system mounted on, for example, an electric vehicle.

Background Art

[0002] Patent Document 1 discloses a thermal management system for an electric vehicle that supplies power from an in-vehicle battery to a drive motor and runs by the power of the drive motor. In the thermal management system of Patent Document 1, by circulating a coolant through a battery temperature control circuit and a drive device temperature control circuit, temperature control of the battery and the drive device is executed, and the coolant whose temperature has risen is cooled by a radiator circuit and can also be cooled by a chiller circuit connected to a refrigeration cycle.

[0003] In the thermal management system of Patent Document 1, when it is desired to raise the temperature of the battery, the battery temperature control circuit, the chiller circuit, the radiator circuit, and the drive device temperature control circuit are connected in series in order from the upstream side of the flow direction of the coolant, and the heat generated from the drive device is used to raise the temperature of the battery.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the vehicle thermal management system includes a chiller connected to the battery temperature control circuit and the refrigeration cycle, not only can the temperature of the battery be adjusted by the coolant whose temperature has been adjusted by exchanging heat with the refrigerant of the refrigeration cycle, but also the waste heat of the battery can be effectively utilized for the heating of the refrigeration cycle, leading to a reduction in power consumption.

[0006] By the way, if the temperature of the drive unit drops, for example, due to prolonged storage in cold conditions, the drive unit is in a low-temperature state. In such situations, if the drive unit temperature control circuit and the battery temperature control circuit are connected in series, as in Patent Document 1, the coolant fluid that has flowed through the battery temperature control circuit will absorb heat in the drive unit as it flows through the drive unit temperature control circuit. As a result, the waste heat from the battery cannot be used for heating in the refrigeration cycle, which leads to an increase in the power required for heating.

[0007] This disclosure is made in view of the above points, and its purpose is to prevent waste heat from the battery from being absorbed by the drive unit when the temperature of the drive unit is low, and to enable the effective use of the battery's waste heat for heating. [Means for solving the problem]

[0008] To achieve the above objective, one aspect of this disclosure may be based on a vehicle thermal management system installed in a vehicle that runs on power supplied from a battery to a drive unit. The vehicle thermal management system includes an oil cooler through which the oil of the drive unit flows, a compressor for compressing a refrigerant, an outdoor condenser into which the refrigerant compressed by the compressor flows, and a chiller expansion valve for expanding the refrigerant that has flowed out of the outdoor condenser, a chiller connected between the chiller expansion valve and the compressor of the refrigerant circuit, a first circuit configured to allow the flow of a heat transfer medium and to adjust the temperature of the battery by the flowing heat transfer medium, and a circuit configured to allow the flow of the heat transfer medium and to adjust the temperature of the oil by exchanging heat between the flowing heat transfer medium and the oil flowing through the oil cooler. The system includes a second circuit, a third circuit having a radiator configured to allow the flow of the heat transfer medium and to exchange heat between the flowing heat transfer medium and the outside air, a fourth circuit configured to allow the flow of the heat transfer medium and connected to the chiller, and a control unit that, when the oil temperature of the oil cooler is lower than a first temperature, connects the first circuit and the fourth circuit to form a first heat transfer medium circuit and disconnects the second circuit from the first heat transfer medium circuit, while when the oil temperature of the oil cooler is equal to or higher than the first temperature, connects the first circuit, the second circuit, the third circuit and the fourth circuit to form a second heat transfer medium circuit.

[0009] With this configuration, if the temperature of the drive unit is low, such as when it is left in cold conditions for a long period of time, the control unit connects the first circuit and the fourth circuit to form a first heat transfer fluid circuit. Since this first heat transfer fluid circuit is disconnected from the second circuit that regulates the temperature of the oil in the drive unit's oil cooler, the heat transfer fluid flowing through the first heat transfer fluid circuit is not heated by the low-temperature oil. As a result, during heating, the waste heat from the battery can be absorbed by the refrigerant in the refrigerant circuit via the chiller and effectively utilized as a heat source for heating.

[0010] On the other hand, when the temperature of the drive unit is high, the first, second, third, and fourth circuits are connected, allowing the heat transfer medium to be cooled by the radiator in the third circuit and by the chiller in the fourth circuit. This ensures sufficient cooling capacity for the drive unit and battery.

[0011] The drive device may include a drive motor and an inverter for controlling the drive motor. The oil cooler may be through which the oil of the drive motor flows, and the heat transfer medium of the second circuit may cool the inverter. In this case, the control unit can form the first heat transfer medium circuit when the temperature of the oil in the oil cooler is higher than the temperature of the heat transfer medium of the second circuit, and can form the second heat transfer medium circuit when the temperature of the oil in the oil cooler is lower than or equal to the temperature of the heat transfer medium of the second circuit.

[0012] The vehicle thermal management system may further include a battery temperature sensor that acquires the temperature of the battery. In this case, the control unit determines whether the battery temperature acquired by the battery temperature sensor is equal to or greater than a second temperature, and if the battery temperature acquired by the battery temperature sensor is equal to or greater than the second temperature, the first heat transfer medium circuit can be formed. That is, if the battery temperature is equal to or greater than the second temperature, waste heat from the battery can be obtained, and in this case, the first heat transfer medium circuit can be formed to effectively utilize the waste heat from the battery for heating.

[0013] The control unit can also connect the second, third, and fourth circuits to form a third heat transfer medium circuit and disconnect the first circuit from the third heat transfer medium circuit if the battery temperature obtained by the battery temperature sensor is below the second temperature. This allows the first circuit to be disconnected when the battery temperature is low and it is unlikely that waste heat from the battery can be obtained. In this case, if the drive unit generates a lot of heat, the second circuit can absorb the waste heat from the drive unit, so that the waste heat from the drive unit can be absorbed by the refrigerant in the refrigerant circuit via the chiller and effectively used as a heat source for heating.

[0014] The control unit forms the third heat transfer medium circuit when the temperature of the oil in the oil cooler is higher than the temperature of the heat transfer medium in the second circuit. Conversely, when the temperature of the oil in the oil cooler is lower than or equal to the temperature of the heat transfer medium in the second circuit, it connects the third and fourth circuits to form a fourth heat transfer medium circuit, and can also disconnect the first and second circuits from the fourth heat transfer medium circuit. In other words, when the oil temperature is relatively low, disconnecting the second circuit from the third and fourth circuits suppresses further decreases in the oil temperature. This suppresses a decrease in the viscosity of the oil, which reduces the flow resistance of the oil within the drive unit and makes it possible to reduce power consumption.

[0015] The vehicle thermal management system may further include a temperature sensor for acquiring the outlet temperature of the heat transfer medium in the chiller, and an outside air temperature sensor for acquiring the outside air temperature. The control unit can activate an electric fan to supply outside air to the radiator if the outside air temperature acquired by the outside air temperature sensor is higher than the temperature of the heat transfer medium acquired by the temperature sensor.

[0016] The control unit determines whether the vehicle air conditioning system installed in the vehicle is in a heating state, and if it is determined that the vehicle air conditioning system is in a heating state, it can form the first heat transfer medium circuit or the second heat transfer medium circuit. [Effects of the Invention]

[0017] As described above, when the temperature of the drive device is low, the waste heat of the battery can be prevented from being absorbed by the drive device, so that the waste heat of the battery can be effectively used for heating.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a functional block diagram of a vehicle thermal management system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram schematically showing an electric vehicle equipped with a vehicle thermal management system. [Figure 3] FIG. 3 is a diagram showing the flow of the refrigerant and the coolant in the first coolant liquid circuit. [Figure 4] FIG. 4 is a diagram showing the flow of the refrigerant and the coolant in the second coolant liquid circuit. [Figure 5] FIG. 5 is a diagram showing the flow of the refrigerant and the coolant in the third coolant liquid circuit. [Figure 6] FIG. 6 is a diagram showing the flow of the refrigerant and the coolant in the fourth coolant liquid circuit. [Figure 7] FIG. 7 is a diagram showing the flow of the refrigerant and the coolant in the fifth coolant liquid circuit. [Figure 8] FIG. 8 is a flowchart showing the control flow by the control unit.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses. For example, the relative sizes and positional relationships of the components shown in the figures are for the purpose of explaining one embodiment and do not limit the present invention.

[0020] Figure 1 is a functional block diagram of a vehicle thermal management system (hereinafter referred to as the "thermal management system") S according to an embodiment of the present invention. The thermal management system S is mounted on an electric vehicle 1 schematically shown in Figure 2. That is, the electric vehicle 1 is equipped with a front motor MA and a rear motor MB, and a battery B.

[0021] The front motor MA and rear motor MB are drive motors and traction motors that generate the driving force necessary to propel the electric vehicle 1. The front motor MA drives the front wheels, and the rear motor MB drives the rear wheels. Both the front motor MA and the rear motor MB may be mounted on the electric vehicle 1, or only one of them may be mounted on the electric vehicle 1.

[0022] Battery B is not an auxiliary battery, but a high-capacity secondary battery for driving that supplies power to the front motor MA and rear motor MB. A typical example of Battery B is a lithium-ion battery, but the present invention can be applied to any rechargeable battery other than a lithium-ion battery (e.g., a nickel-metal hydride battery). In the case of a lithium-ion battery, its shape may be, for example, pouch-type or cylindrical. When the electric vehicle 1 is braking, the energy regenerated by the front motor MA and rear motor MB is stored as electricity in Battery B.

[0023] The electric vehicle 1 includes a front inverter IA that controls the front motor MA and a rear inverter IB that controls the rear motor MB. For example, the electric vehicle 1 may include a front e-axle (not shown) which includes the front motor MA, the front inverter IA, and a front transaxle (not shown). Alternatively, the electric vehicle 1 may include a rear e-axle (not shown) which includes the rear motor MB, a rear inverter IB, and a rear transaxle (not shown).

[0024] Electric vehicle 1 is equipped with a DC / DC converter and a charge controller (collectively referred to as C). The DC / DC converter and charge controller C are devices that supply current from an external charger (not shown) and supply it to battery B as a charging current of a suitable magnitude for charging battery B. In other words, battery B is charged via the DC / DC converter and charge controller C. Battery B can be charged using both normal charging with a maximum power of 11 kW and fast charging with a power exceeding 11 kW. Hereinafter, "DC / DC converter and charge controller" will simply be referred to as "charge controller". The charge controller receives the alternating current during normal charging.

[0025] Although not an essential component, electric vehicle 1 is equipped with a power supply unit D. Power supply unit D is a device for supplying power from battery B to an external source and includes, for example, an inverter configured to output 100V power.

[0026] The front motor MA, rear motor MB, front inverter IA, rear inverter IB, and charge controller C are examples of elements that constitute the drive system E for driving the electric vehicle 1. The electric vehicle 1 runs by supplying power from the battery B to the drive system E. In this embodiment, the charge controller C is included as part of the drive system E, but the charge controller C does not have to be a component of the drive system E. The power supply unit D may or may not be included as a component of the drive system E. In addition to the equipment described above, the drive system E may also include equipment related to the driving of the electric vehicle 1. Furthermore, equipment that does not require temperature control may be excluded from the drive system E of the present invention.

[0027] In this embodiment, the case in which the thermal management system S is installed in an electric vehicle 1 is described, but it is not limited to this, and for example, the thermal management system S can also be installed in a plug-in hybrid vehicle. When the thermal management system S is installed in a plug-in hybrid vehicle, similar effects and advantages can be achieved.

[0028] The thermal management system S includes a refrigerant circuit 20 through which a refrigerant circulates, and a chiller 30 for utilizing the cold generated in the refrigerant circuit 20, for example, for cooling a battery B. Separate from the refrigerant circuit 20 through which the refrigerant circulates, the thermal management system S also includes, for example, a first circuit 100, a second circuit 200, a third circuit 300, and a fourth circuit 400, which are configured to allow the flow of a heat transfer medium.

[0029] The first circuit 100 is a circuit for adjusting the temperature of battery B using a circulating heat transfer medium. The second circuit 200 is a circuit for adjusting the temperature of drive unit E using a circulating heat transfer medium. The third circuit 300 is a circuit having a radiator 301 that dissipates heat by exchanging heat between the circulating heat transfer medium and the outside air. The fourth circuit 400 is a circuit connected to chiller 30. The heat transfer medium circulating in the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400 is, for example, coolant. In the following description, the heat transfer medium will be described as coolant.

[0030] The thermal management system S further includes an electrically operated 8-way valve 500 for switching the connection states of the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400, and a control unit 600 for controlling each of the devices included in the thermal management system S. The 8-way valve 500 may be included in the control unit 600. First, the specific configurations of the refrigerant circuit 20, the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400 will be described, but the following description is an example and may include other components that are not described.

[0031] (Refrigerant circuit configuration) First, let's describe the refrigerant circuit 20. The refrigerant circuit 20 includes a compressor 21 for compressing the refrigerant, an indoor condenser 22, an outdoor condenser 23, a chiller expansion valve 24, a cooling expansion valve 25, a cooling evaporator 26, an accumulator 27, and refrigerant piping 28. The refrigerant piping 28 is a component for connecting each of the devices 21, 22, 23, 24, 25, 26, and 27, and is provided between each of the devices 21, 22, 23, 24, 25, 26, and 27, so the refrigerant circuit 20 has multiple refrigerant pipes 28. In Figure 2, to avoid clutter on the drawing, not all of the refrigerant pipes are labeled, but only one of them is labeled.

[0032] The compressor 21, although not shown in the figure, is an electric compressor equipped with an electric motor and a compression mechanism operated by the electric motor. As shown in Figure 1, the compressor 21 is connected to a control unit 600, and the control unit 600 controls the switching between ON and OFF states and the rotational speed when ON. The compressor 21 operates by a combination of control based on the requirements of the air conditioning system, the cooling requirements of the battery B, and the cooling requirements of the drive unit E.

[0033] The indoor condenser 22 is connected to the refrigerant discharge port (not shown) of the compressor 21 via refrigerant piping 28, and is a heat exchanger into which the high-temperature, high-pressure refrigerant compressed by the compressor 21 flows. The indoor condenser 22 is installed inside the vehicle cabin and is a device for heating the vehicle cabin. The vehicle cabin is the space in which the occupants are seated.

[0034] The outdoor condenser 23 is connected to the refrigerant outlet (not shown) of the indoor condenser 22 via refrigerant piping 28 and is a heat exchanger into which the refrigerant that has flowed through the indoor condenser 22, i.e., the refrigerant compressed by the compressor 21, flows. The outdoor condenser 23 is located outside the vehicle. Outside the vehicle is a space outside the space where the occupants are seated, where heat exchange with the outside air is possible. Examples of areas outside the vehicle include the motor room (not shown) where the front motor MA and rear motor MB are housed, and the front of the vehicle (for example, inside the front grille).

[0035] The electric vehicle 1 of this embodiment is equipped with a grill shutter GS. The grill shutter GS is a device for opening and closing the opening of the front grill (not shown), and has a grill shutter actuator GS1 as shown in Figure 1. The grill shutter actuator GS1 is connected to a control unit 600, which controls the operation of the grill shutter GS from an open state to a closed state and from a closed state to an open state. When the outdoor condenser 23 is located inside the front grill, closing the grill shutter GS reduces the amount of outside air flowing into the outdoor condenser 23, and opening the grill shutter GS increases the amount of outside air flowing into the outdoor condenser 23.

[0036] The cooling evaporator 26 is installed inside the vehicle cabin and is a device for cooling the cabin or dehumidifying the air supplied to the cabin. The refrigerant outlet (not shown) of the outdoor condenser 23 and the refrigerant inlet (not shown) of the cooling evaporator 26 are connected by refrigerant piping 28. Between the outdoor condenser 23 and the cooling evaporator 26 in the refrigerant piping 28, there is a cooling expansion valve 25 that expands the refrigerant flowing out from the outdoor condenser 23. The refrigerant expanded by the cooling expansion valve 25 flows into the cooling evaporator 26. The cooling expansion valve 25 is connected to a control unit 600, and the opening degree can be changed by the control unit 600.

[0037] The refrigerant piping 28 includes chiller piping 28a extending to the chiller 30. The chiller 30 is a heat exchanger connected between the chiller expansion valve 24 and the compressor 21, and is configured to exchange heat with a heat transfer medium, which will be described later. The chiller 30 is located away from the outdoor condenser 23 and the radiator 301.

[0038] Chiller piping 28a branches off from the refrigerant piping 28 upstream of the cooling expansion valve 25, and refrigerant flowing out from the outdoor condenser 23 flows into chiller piping 28a. Chiller piping 28a is equipped with a chiller expansion valve 24 that expands the refrigerant flowing out from the outdoor condenser 23. The refrigerant inlet (not shown) of chiller 30 is connected downstream of the chiller expansion valve 24 in chiller piping 28a. Therefore, refrigerant expanded by the chiller expansion valve 24 flows into chiller 30.

[0039] The downstream side of the chiller piping 28a is connected to the refrigerant inlet (not shown) of the accumulator 27. The refrigerant outlet of the cooling evaporator 26 is also connected to the refrigerant inlet of the accumulator 27. The accumulator 27 performs gas-liquid separation of the refrigerant that flows in through the chiller 30 and / or the cooling evaporator 26. The liquid refrigerant outlet (not shown) of the accumulator 27 is connected to the refrigerant suction port (not shown) of the compressor 21.

[0040] The refrigerant circuit 20 is provided with a check valve 20a between the outdoor condenser 23 and the chiller expansion valve 24 and the cooling expansion valve 25. This check valve 20a prevents the backflow of refrigerant from the chiller expansion valve 24 and cooling expansion valve 25 to the outdoor condenser 23.

[0041] The refrigerant circuit 20 is provided with a check valve 20b between the cooling evaporator 26 and the chiller 30 and accumulator 27. This check valve 20b prevents the backflow of refrigerant from the chiller 30 and accumulator 27 to the cooling evaporator 26.

[0042] The refrigerant circuit 20 includes an indoor two-way valve 20c and an outdoor two-way valve 20d. The indoor two-way valve 20c and the outdoor two-way valve 20d are composed of, for example, solenoid valves and are connected to a control unit 600, so that their opening and closing operations are controlled by the control unit 600. The indoor two-way valve 20c is installed between the indoor condenser 22 and the cooling evaporator 26. When opened by the control unit 600, the refrigerant flowing out of the indoor condenser 22 flows into the chiller expansion valve 24 and the cooling expansion valve 25. When closed by the control unit 600, the refrigerant flowing out of the indoor condenser 22 does not flow into the chiller expansion valve 24 and the cooling expansion valve 25. In other words, the indoor two-way valve 20c controls the flow of refrigerant to the cooling evaporator 26 and the chiller 30.

[0043] The outdoor two-way valve 20d is installed between the indoor condenser 22 and the outdoor condenser 23. When opened by the control unit 600, refrigerant flowing out of the indoor condenser 22 flows into the outdoor condenser 23. Conversely, when closed by the control unit 600, refrigerant flowing out of the indoor condenser 22 is prevented from flowing into the outdoor condenser 23. In other words, the outdoor two-way valve 20d controls the flow of refrigerant to the outdoor condenser 23.

[0044] The refrigerant circuit 20 includes a high-pressure side refrigerant pressure sensor 20A, a high-pressure side refrigerant temperature sensor 20B, a cooling side refrigerant temperature sensor 20C, and a chiller side refrigerant temperature sensor 20D. The high-pressure side refrigerant pressure sensor 20A is located downstream of the indoor condenser 22 and the outdoor condenser 23, and upstream of the chiller expansion valve 24 and the cooling expansion valve 25, and acquires the pressure of the refrigerant flowing through that location. The refrigerant pressure acquired by the high-pressure side refrigerant pressure sensor 20A is output to the control unit 600.

[0045] The high-pressure refrigerant temperature sensor 20B is located downstream of the indoor condenser 22 and the outdoor condenser 23, and upstream of the chiller expansion valve 24 and the cooling expansion valve 25, and acquires the temperature of the refrigerant flowing through that location. The refrigerant temperature acquired by the high-pressure refrigerant temperature sensor 20B is output to the control unit 600.

[0046] The cooling-side refrigerant temperature sensor 20C is installed between the cooling evaporator 26 and the check valve 20b, and acquires the temperature of the refrigerant flowing through that point. In other words, the cooling-side refrigerant temperature sensor 20C acquires the temperature of the refrigerant after it has flowed out of the cooling evaporator 26. The refrigerant temperature acquired by the cooling-side refrigerant temperature sensor 20C is output to the control unit 600.

[0047] The chiller-side refrigerant temperature sensor 20D is installed between the chiller 30 and the accumulator 27, and acquires the temperature of the refrigerant flowing through that point. In other words, the chiller-side refrigerant temperature sensor 20D acquires the temperature of the refrigerant after it has flowed out of the chiller 30. The refrigerant temperature acquired by the chiller-side refrigerant temperature sensor 20D is output to the control unit 600.

[0048] The indoor condenser 22 and the cooling evaporator 26 constitute part of the vehicle air conditioning system 40. The vehicle air conditioning system 40 also includes an indoor electric heater 41 and a blower motor 42 (shown in Figure 1). The blower motor 42 is a device for blowing outside air and / or inside air to the indoor condenser 22, the cooling evaporator 26, and the indoor electric heater 41. The indoor electric heater 41 and the blower motor 42 are connected to and controlled by a control unit 600.

[0049] The vehicle air conditioning system 40 is equipped with an air mix actuator 43 (shown in Figure 1) that operates an air mix damper (not shown). The air mix actuator 43 is connected to a control unit 600 and controlled by the control unit 600. By operating the air mix damper, the air mix actuator 43 makes it possible to adjust the temperature of the air conditioning supplied to the vehicle cabin.

[0050] In other words, in the vehicle air conditioning system 40, the entire amount of air blown by the blower motor 42 is sent to the cooling evaporator 26. Basically, during cooling operation, the air mix actuator 43 operates the air mix damper so that the entire amount of air that has passed through the cooling evaporator 26 is supplied to the vehicle interior without passing through the interior condenser 22 and the interior electric heater 41.

[0051] On the other hand, during heating operation, the air mix actuator 43 operates the air mix damper so that a portion or all of the air that has passed through the cooling evaporator 26 is supplied to the indoor condenser 22 and indoor electric heater 41, heated, and then supplied to the passenger compartment.

[0052] The control unit 600 determines how much air from the air that has passed through the cooling evaporator 26 should be supplied to the interior condenser 22 and interior electric heater 41, according to the target temperature inside the vehicle cabin, and controls the air mix actuator 43 so that that amount of air is supplied to the interior condenser 22 and interior electric heater 41. The interior electric heater 41 has a heating element that generates heat when power is supplied, such as a PTC element. The interior electric heater 41 may be provided as needed.

[0053] (Configuration of the first circuit) The first circuit 100 is a circuit for regulating the temperature of battery B, and can also be called a temperature regulation circuit for battery B. The first circuit 100 includes a coolant heater 101 and a first coolant pipe 102.

[0054] The coolant heater 101 is an electric heater controlled by the control unit 600, and has a heating element that generates heat when power is supplied, such as a PTC element. When the temperature of battery B is too low to be suitable for charging and discharging, the control unit 600 activates the coolant heater 101 to heat the coolant. When the temperature of battery B is within the temperature range suitable for charging and discharging, or when the temperature of battery B exceeds the temperature range suitable for charging and discharging, the control unit 600 stops the coolant heater 101.

[0055] The first coolant pipe 102 is a pipe for circulating coolant fluid within the first circuit 100 via an eight-way valve 500. The upstream and downstream ends of the first coolant pipe 102 are connected to the connection ports of the eight-way valve 500. A coolant heater 101 is provided upstream of the first coolant pipe 102. A battery B is provided downstream of the coolant heater 101 in the first coolant pipe 102.

[0056] A heat exchanger (not shown) is provided in a portion of the first coolant piping 102, and this heat exchanger is positioned to be in contact with the outer surface of the battery B. Heat exchange takes place between the coolant liquid circulating inside the heat exchanger and the battery B. When the temperature of the battery B is higher than the temperature of the coolant liquid, the battery B is cooled, and conversely, when the temperature of the battery B is lower than the temperature of the coolant liquid, the battery B is heated.

[0057] The first circuit 100 is equipped with a heater temperature sensor 101a and a battery temperature sensor 100a. The heater temperature sensor 101a is a sensor for acquiring the temperature of the coolant heater 101. The heater temperature acquired by the heater temperature sensor 101a is output to the control unit 600.

[0058] The battery temperature sensor 100a is a sensor for obtaining the temperature of battery B. The battery temperature sensor 100a may obtain the temperature of battery B by, for example, obtaining the temperature of the cell surface or the vicinity of the cells of battery B, or by obtaining the temperature of the coolant fluid in the vicinity of battery B. The position and location of the battery temperature sensor 100a are not particularly limited. The information regarding the temperature of battery B obtained by the battery temperature sensor 100a is output to the control unit 600.

[0059] (2nd circuit) The second circuit 200 is a circuit for controlling the temperature of the drive unit E, and can also be called, for example, a temperature control circuit for the drive unit E. The second circuit 200 includes a first coolant pump 201, a separation tank 202, and a second coolant pipe 203.

[0060] The second coolant pipe 203 is a pipe for circulating coolant liquid within the second circuit 200 via an eight-way valve 500. The upstream and downstream ends of the second coolant pipe 203 are connected to the connection ports of the eight-way valve 500. The first coolant pump 201 is located upstream of the second coolant pipe 203 and sends the coolant liquid in the second coolant pipe 203 downstream, creating a circulating flow. A drive unit E is located downstream of the first coolant pump 201 in the second coolant pipe 203. The drive unit E is a cooling target device that is cooled by the coolant liquid flowing through the second circuit 200.

[0061] The order in which coolant is supplied to the front motor MA, rear motor MB, front inverter IA, rear inverter IB, charge controller C, and power supply D included in the drive unit E is not particularly limited, but in this embodiment, the second coolant piping 203 is configured so that the coolant is supplied in the following order. That is, the front inverter IA, charge controller C, power supply D, rear inverter IB, rear motor MB, and front motor MA are connected in series in the second coolant piping 203 in the order from the upstream side to the downstream side in the direction of coolant flow.

[0062] The front motor MA and rear motor MB are oil-cooled, using a circulating oil system for cooling. Specifically, the thermal management system S includes a front oil cooler FC through which the oil for the front motor MA flows and cools it, and a rear oil cooler RC through which the oil for the rear motor MB flows and cools it. If only the front motor MA is present, the rear oil cooler RC is omitted; if only the rear motor MB is present, the front oil cooler FC is omitted. A single oil cooler common to both the front motor MA and rear motor MB may also be provided. The following description will focus on the case where both the front oil cooler FC and the rear oil cooler RC are provided.

[0063] In the second circuit 200, the coolant fluid circulating in the second circuit 200 is heat-exchanged with the oil in the front oil cooler FC and the rear oil cooler RC to adjust the oil temperature. In this embodiment, since the rear oil cooler RC is located upstream of the front oil cooler FC, the coolant fluid that has heat-exchanged with the oil in the rear oil cooler RC then heat-exchanges with the oil in the front oil cooler FC.

[0064] As shown in Figure 1, the thermal management system S is equipped with an oil temperature sensor 602. Although only one oil temperature sensor 602 is shown in Figure 1, the oil temperature sensor 602 acquires the oil temperature of the front motor MA and the oil temperature of the rear motor MB. The oil temperature sensor 602 is connected to the control unit 600 and outputs the acquired oil temperature information to the control unit 600.

[0065] The front inverter IA, charge controller C, power supply D, rear inverter IB, etc., may also be oil-cooled or water-cooled. In the case of water cooling, the front inverter IA, charge controller C, power supply D, rear inverter IB, etc., can be cooled using a heat exchange structure (not shown) provided in a part of the second coolant piping 203. That is, although the structure is not particularly limited, the front inverter IA, charge controller C, power supply D, and rear inverter IB can be cooled by heat exchange between the coolant liquid flowing through the heat exchange structure of the second coolant piping 203 and the front inverter IA, charge controller C, power supply D, and rear inverter IB.

[0066] In this embodiment, the front inverter IA, charge controller C, power supply D, and rear inverter IB are arranged upstream of the front oil cooler FC and rear oil cooler RC, making it possible to supply relatively low-temperature coolant to the front inverter IA, charge controller C, power supply D, and rear inverter IB with priority.

[0067] The separation tank 202 is located downstream of the drive unit E in the second coolant piping 203. After passing through the drive unit E, the coolant flows into the separation tank 202 and then to the 8-way valve 500. Although not shown in the figure, the separation tank 202 is connected to a reserve tank where the coolant is stored.

[0068] The second circuit 200 is equipped with a coolant temperature sensor 200a. The coolant temperature sensor 200a is a sensor for obtaining the temperature of the coolant liquid in the second coolant piping 203. The coolant temperature sensor 200a is located between the first coolant pump 201 and the drive unit E.

[0069] A drive unit temperature sensor may be configured using the coolant temperature sensor 200a to acquire the temperature of the drive unit E. For example, by having the coolant temperature sensor 200a acquire the temperature of the coolant fluid flowing through the second circuit 200, the inlet temperature of the drive unit E, i.e., the temperature of the drive unit E, can be acquired. In addition, the thermal management system S may have a drive unit temperature sensor that acquires the temperature of the drive unit E separately from the coolant temperature sensor 200a. For example, a temperature sensor that acquires the temperature of relatively heat-sensitive equipment such as the front inverter IA and the rear inverter IB can be provided and used as the drive unit temperature sensor. Thus, the location and position of the drive unit temperature sensor are not particularly limited. The following describes the case where the coolant temperature sensor 200a is used as the drive unit temperature sensor. The information regarding the temperature of the drive unit E acquired by the coolant temperature sensor 200a is output to the control unit 600.

[0070] (3rd circuit) The third circuit 300 includes a radiator 301 for dissipating the heat of the coolant to the outside air, as well as a third coolant pipe 302 and an electric fan 303. The radiator 301, like the outdoor condenser 23, is located outside the vehicle. In this embodiment, the outdoor condenser 23 is located inside the front grille to ensure sufficient ventilation, and the radiator 301 is positioned behind the outdoor condenser 23 (downstream in the direction of outside airflow) located inside the front grille. The outdoor condenser 23 and the radiator 301 may be modularized in a stacked state in the direction of outside airflow, or the outdoor condenser 23 and the radiator 301 may be mounted separately on the vehicle body. In any case, the positional relationship between the outdoor condenser 23 and the radiator 301 is set so that outside air that has passed through the outdoor condenser 23 is introduced into the radiator 301.

[0071] The third coolant pipe 302 is a pipe for circulating coolant fluid within the third circuit 300 via the eight-way valve 500. The upstream and downstream ends of the third coolant pipe 302 are connected to the connection ports of the eight-way valve 500.

[0072] The electric fan 303 is a device for supplying outside air to the radiator 301 and is installed, for example, inside the front grille. When the electric fan 303 is activated, the control unit 600 controls the grille shutter actuator GS1 to open the grille shutter GS.

[0073] The direction of the outside airflow formed by the electric fan 303 is from the front to the rear of the vehicle. This direction of outside airflow is the same as the direction of outside airflow when the electric vehicle 1 is in motion. Since the outdoor condenser 23 is located in front of the radiator 301, the outside air flows through the outdoor condenser 23 via the flow formed by the electric fan 303 before flowing into the radiator 301. The same outside airflow occurs when the electric vehicle 1 is in motion. The electric fan 303 is connected to the control unit 600, and the control unit 600 switches it ON and OFF and controls its rotation speed when ON according to the heat dissipation requirement. The electric fan 303 operates not only to send outside air to the radiator 301, but also when the refrigerant circuit 20 is operating, sending outside air to the outdoor condenser 23. Therefore, it can be said that the electric fan 303 also constitutes a part of the refrigerant circuit 20.

[0074] (4th circuit) The fourth circuit 400 is a circuit for cooling the coolant liquid with the chiller 30, and can also be called a coolant liquid cooling circuit. The fourth circuit 400 comprises a second coolant pump 401 and a fourth coolant pipe 402. The fourth coolant pipe 402 is a pipe for circulating the coolant liquid within the fourth circuit 400 via an eight-way valve 500. The upstream and downstream ends of the fourth coolant pipe 402 are connected to the connection ports of the eight-way valve 500.

[0075] The second coolant pump 401 is located in the fourth coolant piping 402 and sends the coolant liquid in the fourth coolant piping 402 downstream, creating a circulating flow. A chiller 30 is located upstream of the second coolant pump 401 in the fourth coolant piping 402.

[0076] The chiller 30 is provided with a refrigerant flow path through which the refrigerant supplied by the chiller piping 28a of the refrigerant circuit 20 flows, and a coolant flow path through which the coolant supplied by the fourth coolant piping 402 flows. The refrigerant flowing through the refrigerant flow path and the coolant flowing through the coolant flow path are capable of heat exchange, and when the temperature of the coolant is higher than the temperature of the refrigerant, the coolant can be cooled.

[0077] The fourth circuit 400 is equipped with a chiller temperature sensor 400a. The chiller temperature sensor 400a is a sensor for obtaining the temperature of the coolant liquid after it has been cooled by the chiller 30. The temperature of the coolant liquid obtained by the chiller temperature sensor 400a is output to the control unit 600. The fourth coolant pipe 402 of the fourth circuit 400 is connected to a reserve tank (not shown).

[0078] (Control unit) The control unit 600 includes, for example, a microcomputer containing a central processing unit, ROM (Read Only Memory), RAM (Random Access Memory), various signal processing units, input / output interfaces, etc. A program is stored in the memory unit (not shown) of the control unit 600, and the central processing unit performs various processes and controls as described below in accordance with the program.

[0079] The control unit 600 includes a part for controlling the vehicle air conditioning system 40, a part for controlling the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400, and a part for controlling the 8-way valve 500. These can be configured as a combination of hardware and software, or as hardware only.

[0080] The part for controlling the vehicle air conditioning system 40, the part for controlling the first circuit 100, the second circuit 200, the third circuit 300, the fourth circuit 400, and the part for controlling the 8-way valve 500 may be physically separate. Alternatively, the part for controlling the vehicle air conditioning system 40, the part for controlling the first circuit 100, the second circuit 200, the third circuit 300, the fourth circuit 400, and the part for controlling the 8-way valve 500 may be integrated. Furthermore, the control unit 600 may include a part for controlling the vehicle's drive system E. Thus, the configuration of the control unit 600 is not particularly limited, and it may be configured to integrate and control in-vehicle equipment and devices. For example, it can be configured to acquire vehicle speed information, thereby enabling control based on vehicle speed.

[0081] The control unit 600 is connected to an outside air temperature sensor 601 that acquires the outside air temperature, and the outside air temperature acquired by the outside air temperature sensor 601 (acquired outside air temperature) is input to the control unit 600. The outside air temperature sensor 601 is a component of the thermal management system S. The location of the outside air temperature sensor 601 is not particularly limited, but for example, it can be located on the upstream side in the direction of outside air flow in the front grille. In addition, although not shown in the figures, an interior air temperature sensor that acquires the temperature inside the vehicle, an operation panel for adjusting the set temperature of the air conditioning, etc., are also connected to the control unit 600.

[0082] Furthermore, the 8-way valve 500 is a device for connecting or disconnecting two or more of the first circuit 100, second circuit 200, third circuit 300, and fourth circuit 400, and is controlled by the control unit 600 as described below. Note that the connection and disconnection of the first circuit 100, second circuit 200, third circuit 300, and fourth circuit 400 shown below is just one example, and other connections and disconnections can also be performed.

[0083] (Specific control by the control unit) The control unit 600 controls the refrigerant circuit 20 and the vehicle air conditioning system 40 when air conditioning the vehicle interior. As shown in Figure 3, in heating operation to heat the vehicle interior, the control unit 600 operates the compressor 21 of the refrigerant circuit 20 to supply high-temperature, high-pressure refrigerant to the interior condenser 22 and condense it, thereby turning the interior condenser 22 into an air heater. The control unit 600 operates the interior electric heater 41 as needed, as well as the blower motor 42 of the vehicle air conditioning system 40, and further controls the air mix actuator 43 to operate the air mix damper so that air-conditioned air at the target temperature is obtained. The obtained air-conditioned air is supplied to various parts of the vehicle interior.

[0084] Although not shown in the diagram, during cooling operation to cool the vehicle interior, the control unit 600 operates the compressor 21 of the refrigerant circuit 20 to supply high-temperature, high-pressure refrigerant to the indoor condenser 22 and outdoor condenser 23 for condensation. Then, the two-layer gas-liquid refrigerant, expanded by the cooling expansion valve 25, is supplied to the cooling evaporator 26 for evaporation, thereby turning the cooling evaporator 26 into an air cooler. The control unit 600 operates the blower motor 42 of the vehicle air conditioning system 40 and further controls the air mix actuator 43 to operate the air mix damper so that conditioned air at the target temperature is obtained. If cooling of the vehicle interior is not required, the blower motor 42 can be stopped. This virtually eliminates heat absorption by the cooling evaporator 26.

[0085] In Figure 3, the areas where the refrigerant flows are shown with a solid black fill, and the areas where the coolant liquid flows are shown with hatched lines. The operation of the first coolant liquid circuit shown in Figure 3 is referred to as the first heating operation. In the first heating operation, the control unit 600 controls the 8-way valve 500 to connect the first coolant pipe 102 of the first circuit 100 and the fourth coolant pipe 402 of the fourth circuit 400 to form the first coolant liquid circuit, and also connects the second coolant pipe 203 of the second circuit 200 and the third coolant pipe 302 of the third circuit 300, and further disconnects the first circuit 100 and the fourth circuit 400 from the second circuit 200 and the third circuit 300. The circuit formed by the first circuit 100 and the fourth circuit 400 is referred to as the first coolant liquid circuit (first heat transfer medium circuit).

[0086] The control unit 600 then activates the second coolant pump 401. When the second coolant pump 401 is activated, the coolant liquid flows from the second coolant pump 401 through the 8-way valve 500, the first coolant pipe 102, the coolant heater 101, the battery B, the 8-way valve 500, the fourth coolant pipe 402, and the chiller 30, and is then drawn into the second coolant pump 401. In this way, the coolant liquid is circulated through the first circuit 100 and the fourth circuit 400.

[0087] The first coolant fluid circuit, formed by the first circuit 100 and the fourth circuit 400, is disconnected from the second circuit 200, which regulates the temperature of the oil in the oil coolers FC and RC. Therefore, the coolant fluid flowing through the first coolant fluid circuit is not heated by the oil at a low temperature. As a result, during heating, the waste heat from the battery B can be absorbed by the refrigerant in the refrigerant circuit 20 via the chiller 30 and effectively utilized as a heat source for heating.

[0088] Furthermore, the control unit 600 activates the first coolant pump 201. When the first coolant pump 201 is activated, the coolant liquid flows from the first coolant pump 201 to the drive unit E, separation tank 202, 8-way valve 500, third coolant pipe 302, radiator 301, 8-way valve 500, second coolant pipe 203, and then is drawn into the first coolant pump 201, due to the connection between the second coolant pipe 203 of the second circuit 200 and the third coolant pipe 302 of the third circuit 300.

[0089] When the temperatures of the front motor MA and rear motor MB rise, the control unit 600 forms a second coolant fluid circuit (second heat transfer medium circuit), as shown in Figure 4. When forming the second coolant fluid circuit, the control unit 600 controls the 8-way valve 500 to connect the first coolant pipe 102 of the first circuit 100, the second coolant pipe 203 of the second circuit 200, the third coolant pipe 302 of the third circuit 300, and the fourth coolant pipe 402 of the fourth circuit 400. The circuit formed by the first circuit 100, the second circuit 200, the third circuit 300, and the fourth circuit 400 is referred to as the second coolant fluid circuit.

[0090] The control unit 600 then operates the first coolant pump 201 and / or the second coolant pump 401. When the first coolant pump 201 and / or the second coolant pump 401 are operated, the coolant flows in the following order from the radiator 301: 8-way valve 500, first coolant pump 201, drive unit E, separation tank 202, 8-way valve 500, coolant heater 101, battery B, 8-way valve 500, chiller 30, second coolant pump 401, 8-way valve 500, and finally back to the radiator 301. In the second coolant fluid circuit, the waste heat from the drive unit E and the waste heat from the battery B are absorbed by the coolant in the coolant circuit 20 via the chiller 30 and can be effectively used as a heat source for heating. In the second coolant fluid circuit, only one of the first coolant pump 201 or the second coolant pump 401 may be operated; however, from the viewpoint of increasing the amount of heat exchange in each component, it may be preferable to operate both the first coolant pump 201 and the second coolant pump 401.

[0091] Furthermore, if it is desired to keep battery B warm and heat dissipation from the drive unit E is required, the control unit 600 forms a third coolant fluid circuit (third heat transfer medium circuit) as shown in Figure 5. When forming the third coolant fluid circuit, the control unit 600 controls the 8-way valve 500 to connect the second coolant pipe 203 of the second circuit 200, the third coolant pipe 302 of the third circuit 300, and the fourth coolant pipe 402 of the fourth circuit 400. The circuit formed by the second circuit 200, the third circuit 300, and the fourth circuit 400 is referred to as the third coolant fluid circuit. The first circuit 100 is kept disconnected from the second circuit 200, the third circuit 300, and the fourth circuit 400.

[0092] The control unit 600 then operates the first coolant pump 201 and / or the second coolant pump 401. When the first coolant pump 201 and / or the second coolant pump 401 are operated, the coolant flows from the radiator 301 in the following order: 8-way valve 500, first coolant pump 201, drive unit E, separation tank 202, 8-way valve 500, chiller 30, second coolant pump 401, 8-way valve 500, and finally back to the radiator 301. In the third coolant fluid circuit, the first circuit 100, which regulates the temperature of the battery B, is disconnected from the second circuit 200, third circuit 300, and fourth circuit 400, so the battery B can be kept warm. Also, since the second circuit 200, third circuit 300, and fourth circuit 400 are connected, the waste heat from the drive unit E can be absorbed by the refrigerant in the refrigerant circuit 20 via the chiller 30 and effectively utilized as a heat source for heating.

[0093] Furthermore, if it is desired to keep battery B warm and heat dissipation from the drive unit E is not required, the control unit 600 forms a fourth coolant fluid circuit (fourth heat transfer medium circuit) as shown in Figure 6. When forming the fourth coolant fluid circuit, the control unit 600 controls the 8-way valve 500 to connect the third coolant pipe 302 of the third circuit 300 to the fourth coolant pipe 402 of the fourth circuit 400. The circuit formed by the third circuit 300 and the fourth circuit 400 is referred to as the fourth coolant fluid circuit. The first circuit 100 and the second circuit 200 are kept separate from the third circuit 300 and the fourth circuit 400. Also, the first circuit 100 and the second circuit 200 are kept separate.

[0094] The control unit 600 then operates the first coolant pump 201 and the second coolant pump 401. When the first coolant pump 201 is operated, coolant flows from the drive unit E, separation tank 202, 8-way valve 500, and the first coolant pump 201. When the second coolant pump 401 is operated, coolant flows from the radiator 301 in the following order: 8-way valve 500, chiller 30, second coolant pump 401, 8-way valve 500, and back to the radiator 301. In the fourth coolant fluid circuit, the first circuit 100, which regulates the temperature of the battery B, is disconnected from the second circuit 200, the third circuit 300, and the fourth circuit 400, so that the battery B can be kept warm. Furthermore, because the second circuit 200 and the third circuit 300 are disconnected, the coolant from the second circuit 200 does not flow through the radiator 301 of the third circuit 300, so it does not dissipate heat to the outside air, and the oil temperature of the front motor MA and rear motor MB does not drop more than necessary.

[0095] Furthermore, when the thermal management system S is in operation, defrosting of the radiator 301 may be necessary. When defrosting the radiator 301, the control unit 600 forms a fifth coolant fluid circuit (fifth heat transfer medium circuit), as shown in Figure 7. When forming the fifth coolant fluid circuit, the control unit 600 controls the 8-way valve 500 to connect the first coolant pipe 102 of the first circuit 100, the second coolant pipe 203 of the second circuit 200, and the third coolant pipe 302 of the third circuit 300. The circuit formed by the first circuit 100, the second circuit 200, and the third circuit 300 is referred to as the fifth coolant fluid circuit. The fourth circuit 4 is kept disconnected from the first circuit 100, the second circuit 200, and the third circuit 300.

[0096] The control unit 600 then determines whether defrosting is necessary if the radiator 301 absorbs heat from the outside air while the thermal management system S is in operation. To determine whether defrosting is necessary, the control unit 600 determines whether the temperature of the coolant at the coolant outlet of the radiator 301 is lower than the outside air temperature by a predetermined temperature or more, and whether this low temperature state has continued for a predetermined time. If the temperature of the coolant at the coolant outlet of the radiator 301 is lower than the outside air temperature obtained by the outside air temperature sensor 601 by a predetermined temperature or more, and this low temperature state has continued for a predetermined time, it can be estimated that defrosting is necessary after the start switch of the electric vehicle 1 is turned OFF. On the other hand, if neither of these temperature conditions or time conditions is met, the control unit 600 determines that defrosting is unnecessary after the start switch of the electric vehicle 1 is turned OFF.

[0097] If the control unit 600 determines that defrosting is necessary in the above defrosting operation determination, it forms a fifth coolant fluid circuit and operates the first coolant pump 201. When the first coolant pump 201 is operated, the coolant flows to the drive unit E, separation tank 202, 8-way valve 500, coolant heater 101, battery B, 8-way valve 500, radiator 301, 8-way valve 500, and the first coolant pump 201. In the fifth coolant fluid circuit, the coolant absorbs heat in the drive unit E and / or battery B before flowing into the radiator 301 of the third circuit 300. As a result, the surface temperature of the radiator 301 rises and the frost on the surface of the radiator 301 melts. The defrosting operation may be performed for several tens of seconds to several minutes, or it may be stopped when the temperature of the coolant at the coolant fluid outlet of the radiator 301 exceeds a certain temperature.

[0098] A specific example of control by the control unit 600 will be explained based on the flowchart shown in Figure 8. The flowchart shown in Figure 8 starts, for example, when the power to the electric vehicle 1 is turned ON. In step SA1 after the start, the control unit 600 determines whether or not the heating in the vehicle interior is ON. For example, if the control unit 600 acquires the operating status of the vehicle air conditioning system 40 and the vehicle air conditioning system 40 is performing heating operation, the process proceeds from step SA1 to step SA2. If the vehicle air conditioning system 40 is not performing heating operation, that is, if the air conditioning is OFF or in cooling operation, the process does not proceed to the following steps.

[0099] In step SA2, it is determined whether the temperature of battery B (hereinafter simply referred to as the temperature of battery B) obtained by the battery temperature sensor 100a is equal to or greater than the target temperature. In this embodiment, the target temperature of battery B is set to 35°C, but it is not limited to this. The target temperature of battery B can be determined based on the target functional state (SOF) of battery B. For example, a map of the requested output and SOF determined from the driving conditions of the electric vehicle 1 is obtained in advance. The requested output is determined from the current driving conditions of the electric vehicle 1, and the target temperature of battery B that can achieve the determined requested output is obtained from the above map. The target temperature of battery B obtained in this way can be used as the judgment threshold in step SA2. In other words, in step SA2, the target temperature of battery B that can achieve the SOF target is compared with the current temperature of battery B. If the current temperature of battery B is equal to or greater than the target temperature, the process proceeds to step SA3. If the current temperature of battery B is less than the target temperature, the process proceeds to step SA10.

[0100] In step SA3, the control unit 600 determines whether the temperature obtained by the oil temperature sensor 602 (hereinafter referred to as the motor oil temperature) is higher than the inverter inlet water temperature. The temperature obtained by the oil temperature sensor 602 is the oil temperature of the oil coolers FC and RC. The inverter inlet water temperature can be, for example, the temperature obtained by the coolant temperature sensor 200a. The inverter inlet water temperature may be the inlet water temperature of the front inverter IA or the inlet water temperature of the rear inverter IB.

[0101] If step SA3 is determined to be YES and the motor oil temperature is higher than the inverter inlet water temperature, the process proceeds to step SA4, where the control unit 600 switches the circuit of the thermal management system S to the first coolant fluid circuit. When switching to this first coolant fluid circuit, the control unit 600 also determines whether the motor oil temperature is lower than the first temperature. If the motor oil temperature is lower than the first temperature and the heat from the battery B in the first circuit 100 is absorbed by the oil coolers FC and RC in the second circuit 200, the control unit 600 switches to the first coolant fluid circuit. In this way, the control unit 600 forms the first coolant fluid circuit when the oil temperature of the oil coolers FC and RC is higher than the coolant fluid temperature of the second circuit 200. As a result, the coolant fluid in the first circuit 100 is not absorbed by the low-temperature oil, and the waste heat from the battery B can be absorbed by the refrigerant in the refrigerant circuit 20 via the chiller 30 during heating, and effectively utilized as a heat source for heating. Furthermore, in step SA2, the control unit 600 determines whether the temperature of battery B, as obtained by the battery temperature sensor 100a, is equal to or greater than the target temperature (second temperature). If the temperature of battery B, as obtained by the battery temperature sensor 100a, is equal to or greater than the target temperature, the control unit 600 forms the first coolant fluid circuit.

[0102] In step SA5, the control unit 600 determines whether the outside air temperature obtained by the outside air temperature sensor 601 is higher than the outlet water temperature (outlet temperature) of the chiller 30. The outlet water temperature of the chiller 30 is the temperature of the coolant liquid obtained by the chiller temperature sensor 400a. If the outside air temperature is higher than the outlet water temperature of the chiller 30, it means that heat can be absorbed from the outside air. In this case, the process proceeds to step SA6, where the control unit 600 controls the grill shutter actuator GS1 to open the grill shutter GS and activate the electric fan 303. This allows heat to be absorbed from the outside air, improving heating efficiency. If the outside air temperature is lower than or equal to the outlet water temperature of the chiller 30, the process proceeds to step SA17, where the control unit 600 determines whether the heating is OFF based on the operating status of the vehicle air conditioning system 40. If the heating is OFF, this control process ends, while if the heating continues, the process returns to step SA2.

[0103] If step SA3 is determined to be NO and the motor oil temperature is below the inverter inlet water temperature, the process proceeds to step SA7, where the control unit 600 switches the circuit of the thermal management system S to the second coolant fluid circuit. When switching to this second coolant fluid circuit, the control unit 600 also determines whether the motor oil temperature is lower than the first temperature. If the motor oil temperature is above the first temperature and there is no risk of heat from the battery B in the first circuit 100 being absorbed by the oil coolers FC and RC in the second circuit 200, the control unit 600 switches to the second coolant fluid circuit. In this way, the control unit 600 forms the second coolant fluid circuit when the oil temperature of the oil coolers FC and RC is below the coolant fluid temperature of the second circuit 200.

[0104] In step SA8, similar to step SA5, the control unit 600 determines whether the outside air temperature obtained by the outside air temperature sensor 601 is higher than the outlet water temperature of the chiller 30. If the outside air temperature is higher than the outlet water temperature of the chiller 30, it means that heat can be absorbed from the outside air. In this case, the process proceeds to step SA9, where the control unit 600 controls the grill shutter actuator GS1 to open the grill shutter GS and activate the electric fan 303. This allows heat to be absorbed from the outside air, improving heating efficiency. If the outside air temperature is lower than or equal to the outlet water temperature of the chiller 30, the process proceeds to step SA17, where the control unit 600 determines whether the heating is OFF based on the operating status of the vehicle air conditioning system 40. If the heating is OFF, this control process ends; however, if the heating continues, the process returns to step SA2.

[0105] In this second coolant fluid circuit, the waste heat from the drive unit E and the waste heat from the battery B can be absorbed by the refrigerant in the refrigerant circuit 20 via the chiller 30 and effectively utilized as a heat source for heating. For example, when the amount of heat absorbed by the chiller 30 is less than the amount of waste heat, and the outlet water temperature of the chiller 30 is, for example, 25°C or higher, the high pressure of the refrigerant in the refrigerant circuit 20 can be suppressed by adjusting the temperature by dissipating heat with the radiator 301. This control can also be performed by the control unit 600.

[0106] If step SA2 is determined to be NO and the current temperature of battery B is below the target temperature, the process proceeds to step SA10. In step SA10, similar to step SA3, the control unit 600 determines whether the motor oil temperature is higher than the inverter inlet water temperature. If step SA10 is determined to be YES and the motor oil temperature is higher than the inverter inlet water temperature, the process proceeds to step SA11, where the control unit 600 switches the circuit of the thermal management system S to the third coolant fluid circuit. In this way, when the temperature of battery B obtained by the battery temperature sensor 100a is below the target temperature, the control unit 600 connects the second circuit 200, the third circuit 300, and the fourth circuit 400 to form the third coolant fluid circuit and disconnects the first circuit 100 from the third coolant fluid circuit. The control unit 600 also forms the third coolant fluid circuit when the oil temperature of the oil coolers FC and RC is higher than the coolant fluid temperature of the second circuit 200.

[0107] In step SA12, similar to step SA5, the control unit 600 determines whether the outside air temperature obtained by the outside air temperature sensor 601 is higher than the outlet water temperature of the chiller 30. If the outside air temperature is higher than the outlet water temperature of the chiller 30, it means that heat can be absorbed from the outside air. In this case, the process proceeds to step SA13, where the control unit 600 controls the grill shutter actuator GS1 to open the grill shutter GS and activate the electric fan 303. This allows heat to be absorbed from the outside air, improving heating efficiency. If the outside air temperature is lower than or equal to the outlet water temperature of the chiller 30, the process proceeds to step SA17, where the control unit 600 determines whether the heating is OFF based on the operating status of the vehicle air conditioning system 40. If the heating is OFF, this control process ends, while if the heating continues, the process returns to step SA2.

[0108] This third coolant fluid circuit is formed when step SA2 is determined to be NO, meaning that the temperature of battery B does not have sufficient margin to reach the target temperature. In such cases, forming the third coolant fluid circuit and disconnecting the first circuit 100 from the second circuit 200, the third circuit 300, and the fourth circuit 400 allows the battery B to be kept warm. Furthermore, since the third coolant fluid circuit connects the second circuit 200, the third circuit 300, and the fourth circuit 400, the heat from the drive unit E can be effectively utilized as heating heat.

[0109] If step SA10 is determined to be NO and the motor oil temperature is below the inverter inlet water temperature, the process proceeds to step SA14, where the control unit 600 switches the circuit of the thermal management system S to the fourth coolant fluid circuit. In this way, when the oil temperature of the oil coolers FC and RC is below the coolant fluid temperature of the second circuit 200, the control unit 600 connects the third circuit 300 and the fourth circuit 400 to form the fourth coolant fluid circuit, and disconnects the first circuit 100 and the second circuit 200 from the fourth coolant fluid circuit.

[0110] In step SA15, similar to step SA5, the control unit 600 determines whether the outside air temperature obtained by the outside air temperature sensor 601 is higher than the outlet water temperature of the chiller 30. If the outside air temperature is higher than the outlet water temperature of the chiller 30, it means that heat can be absorbed from the outside air. In this case, the process proceeds to step SA16, where the control unit 600 controls the grill shutter actuator GS1 to open the grill shutter GS and activate the electric fan 303. This allows heat to be absorbed from the outside air, improving heating efficiency. If the outside air temperature is lower than or equal to the outlet water temperature of the chiller 30, the process proceeds to step SA17, where the control unit 600 determines whether the heating is OFF based on the operating status of the vehicle air conditioning system 40. If the heating is OFF, this control process ends; however, if the heating continues, the process returns to step SA2.

[0111] The embodiments described above are merely illustrative in all respects and should not be interpreted restrictively. Furthermore, any modifications or changes that fall within the equivalent scope of the claims are all within the scope of the present invention.

[0112] In the above-described embodiment, the control unit 600 controlled the grill shutter actuator GS1 and activated the electric fan 303 when opening the grill shutter GS. However, it is also possible to absorb heat from the outside air without activating the electric fan 303. This improves heating efficiency when the amount of heat obtained from absorbing heat from the outside air is less than the power required to operate the electric fan 303. [Industrial applicability]

[0113] As explained above, the vehicle thermal management system described herein can be used, for example, in electric vehicles. [Explanation of Symbols]

[0114] 1 Electric vehicle 20 Refrigerant Circuit 21 Compressor 22 Indoor capacitors 23 Outdoor condenser 24 Chiller expansion valve 25 Cooling Expansion Valve 26. Evaporator for air conditioning 30 Chiller 100 1st circuit 100A Battery Temperature Sensor 200 2nd circuit 300 3rd circuit 301 Radiator 400 4th circuit 600 control unit 601 Outdoor temperature sensor 602 Oil temperature sensor B Battery E Drive Unit S Thermal Management System FC, RC oil cooler IA Front Inverter

Claims

1. A vehicle thermal management system installed in a vehicle that runs by supplying power from a battery to a drive unit, An oil cooler through which the oil of the aforementioned drive unit flows, A refrigerant circuit having a compressor for compressing the refrigerant, an outdoor condenser into which the refrigerant compressed by the compressor flows, and a chiller expansion valve for expanding the refrigerant that has flowed out of the outdoor condenser, A chiller connected between the chiller expansion valve and the compressor of the refrigerant circuit, A first circuit is configured to allow the flow of a heat transfer medium, and the temperature of the battery is adjusted by the flowing heat transfer medium. A second circuit is configured to allow the flow of the heat transfer medium and to adjust the temperature of the oil by exchanging heat between the flowing heat transfer medium and the oil flowing through the oil cooler. A third circuit having a radiator configured to allow the circulation of the heat transfer medium and to exchange heat between the circulating heat transfer medium and the outside air, A fourth circuit is configured to allow the flow of the heat transfer medium and is connected to the chiller, A vehicle thermal management system comprising a control unit that, when the oil temperature of the oil cooler is lower than a first temperature, connects the first circuit and the fourth circuit to form a first heat transfer medium circuit and disconnects the second circuit from the first heat transfer medium circuit, while when the oil temperature of the oil cooler is equal to or higher than the first temperature, connects the first circuit, the second circuit, the third circuit and the fourth circuit to form a second heat transfer medium circuit.

2. In the vehicle thermal management system according to claim 1, The drive device includes a drive motor and an inverter that controls the drive motor. The oil cooler through which the oil of the drive motor flows, The heat transfer medium in the second circuit cools the inverter, A vehicle thermal management system comprising a control unit which forms the first heat transfer medium circuit when the temperature of the oil in the oil cooler is higher than the temperature of the heat transfer medium in the second circuit, and forms the second heat transfer medium circuit when the temperature of the oil in the oil cooler is less than or equal to the temperature of the heat transfer medium in the second circuit.

3. In the vehicle thermal management system according to claim 1, The system further includes a battery temperature sensor that acquires the temperature of the aforementioned battery, The control unit determines whether the battery temperature obtained by the battery temperature sensor is equal to or greater than a second temperature, and if the battery temperature obtained by the battery temperature sensor is equal to or greater than the second temperature, it forms the first heat transfer medium circuit, thereby providing a thermal management system for vehicles.

4. In the vehicle thermal management system according to claim 3, The control unit, when the battery temperature obtained by the battery temperature sensor is below a second temperature, connects the second circuit, the third circuit and the fourth circuit to form a third heat transfer medium circuit and disconnects the first circuit from the third heat transfer medium circuit, is a vehicle thermal management system.

5. In the vehicle thermal management system according to claim 4, The drive device includes a drive motor and an inverter that controls the drive motor. The oil cooler through which the oil of the drive motor flows, The heat transfer medium in the second circuit cools the inverter, A vehicle thermal management system comprising: a control unit which forms the third heat transfer medium circuit when the temperature of the oil in the oil cooler is higher than the temperature of the heat transfer medium in the second circuit, and which connects the third circuit and the fourth circuit to form a fourth heat transfer medium circuit when the temperature of the oil in the oil cooler is less than or equal to the temperature of the heat transfer medium in the second circuit, and disconnects the first circuit and the second circuit from the fourth heat transfer medium circuit.

6. In the vehicle thermal management system according to claim 1, A temperature sensor that acquires the outlet temperature of the heat transfer medium in the chiller, It is further equipped with an outside air temperature sensor that acquires the outside air temperature, The control unit operates an electric fan that sends outside air to the radiator when the outside air temperature obtained by the outside air temperature sensor is higher than the temperature of the heat transfer medium obtained by the temperature sensor, in a vehicle thermal management system.

7. In the vehicle thermal management system according to claim 1, A vehicle thermal management system comprising a control unit that determines whether a vehicle air conditioning system mounted on a vehicle is in a heating state, and if it is determined that the vehicle air conditioning system is in a heating state, forms the first heat transfer medium circuit or the second heat transfer medium circuit.

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