Circuit control method and circuit control device

Abstract

In a circuit control device according to the present embodiment, when (1) a battery temperature is no higher than a charging acceptance temperature, (2) the battery temperature is higher than a battery inlet water temperature of a second cooling water circuit in which second cooling water is circulated for recovering heat used for heating from at least one of a power train and the battery, and (3) a power train outlet water temperature of a first cooling water circuit for cooling the power train is higher than a battery outlet water temperature of the second cooling water circuit, the second cooling water is introduced into the battery and the power train.

Description

Circuit control method and circuit control device

[0001] The present invention relates to a circuit control method and a circuit control device.

[0002] Conventionally, there is known a technology for improving the output (e.g., driving force), durability, etc. of an electric vehicle (electrically driven vehicle) that runs on the driving force of a motor by controlling the temperature of components such as the motor provided in the electric vehicle. For example, Patent Document 1 listed below discloses an electric vehicle that improves driving force and durability by controlling the output torque of each of a plurality of motors using the temperature of each of the motors.

[0003] Japanese Patent Application Laid-Open No. 2018-074655

[0004] However, the above-described conventional techniques do not take into consideration the fuel economy of electric vehicles. In one aspect, the present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a circuit control method and a circuit control device that improve the fuel economy of electric vehicles by appropriately managing the temperatures of components such as the motor.

[0005] In order to solve the above-described problems, a circuit control method according to one aspect of the present invention is a circuit control method that causes a processor to execute a process of recovering heat used for heating a passenger compartment of an electric vehicle from at least one of a powertrain and a battery of the electric vehicle, wherein the processor includes steps of acquiring a powertrain outlet water temperature, which is the temperature of a first coolant in a first coolant circuit through which a first coolant that cools the powertrain circulates, and which is the temperature of the first coolant at a coolant outlet of the powertrain; and acquiring a powertrain outlet water temperature, which is the temperature of a second coolant in a second coolant circuit through which a second coolant that is introduced into at least one of the powertrain and the battery circulates and recovers the heat of at least one of the powertrain and the battery, and which is the temperature of the second coolant at a coolant inlet of the battery. the battery inlet water temperature, which is the temperature of the battery; the battery outlet water temperature, which is the temperature of the second coolant at the coolant outlet of the battery; the battery temperature, which is the temperature of the battery; the battery temperature, which is the temperature of the battery; the battery temperature, which is the temperature of the battery; the battery temperature, which is the temperature of the battery; the battery inlet water temperature, which is the temperature of the battery; the battery temperature, which is the temperature of the battery; the battery inlet water temperature, which is the temperature of the battery; the powertrain outlet water temperature, which is the temperature of the battery;

[0006] According to the present invention, it is possible to provide a circuit control method and a circuit control device that improve the fuel economy of an electric vehicle by appropriately managing the temperature of components such as a motor.

[0007] FIG. 1 is a block diagram showing a schematic configuration of a vehicle equipped with a circuit control device according to an embodiment. FIG. 2 is a diagram explaining that heat from at least one of a powertrain and a battery is recovered by the second coolant circulating through the second coolant circuit of FIG. 1 , and the recovered heat is used to heat the vehicle interior. FIG. 3 is a schematic illustration of an example of a hardware configuration of a circuit control device according to an embodiment. FIG. 4 is a schematic illustration of an example of a software configuration of a circuit control device according to an embodiment. FIG. 5 is a graph for explaining a control signal generated according to the relationship between the battery temperature and the powertrain outlet water temperature of the first coolant. FIG. 6 is an example of a processing procedure of a circuit control device according to an embodiment. FIG. 7 is a block diagram showing a schematic configuration of a modified example in which a radiator is further used to cool the battery.

[0008] An embodiment according to one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described below with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in all respects. Needless to say, various improvements and modifications can be made without departing from the scope of the present invention. In other words, when implementing the present invention, specific configurations according to the embodiment may be appropriately adopted. Note that, although data appearing in the present embodiment are described in natural language, more specifically, they are specified using pseudo-language, commands, parameters, machine language, etc. that can be recognized by a computer.

[0009] §1 Application Example FIG. 1 is a block diagram showing a schematic configuration of a vehicle 1 equipped with a circuit control device (circuit control device 10) according to this embodiment. The vehicle 1 is an electric vehicle, for example, a BEV (Battery Electric Vehicle). As shown in FIG. 1 , the vehicle 1 includes a powertrain 20 and a battery 30. The powertrain 20 includes a drive motor that drives the vehicle 1 and an inverter unit electrically connected to the drive motor. The drive motor not only functions as a motor that drives the drive wheels of the vehicle 1, but may also function as a generator that generates electricity (regenerates power) by rotating the drive wheels when the vehicle 1 decelerates. The inverter unit converts DC power supplied from the battery 30 into AC power suitable for driving the drive motor and supplies it to the drive motor. The inverter unit may further convert regenerative power from the drive motor into DC power suitable for charging the battery 30, thereby charging the battery 30. In addition to the drive motor and inverter unit described above, the powertrain 20 may include other components, such as a speed reducer (gearbox). The speed reducer reduces the rotation of the drive motor and transmits it to a drive shaft to drive the drive wheels.

[0010] The battery 30 is a rechargeable storage battery. The battery 30 is electrically connected to the drive motor included in the powertrain 20 via an inverter unit included in the powertrain 20. The battery 30 discharges drive power to the drive motor included in the powertrain 20, and in this embodiment, supplies power to the powertrain 20, particularly to the inverter unit included in the powertrain 20. The battery 30 is charged by an external power source. The battery 30 may also be charged by regenerative power from the drive motor.

[0011] 1 , the vehicle 1 includes the following components in addition to a powertrain 20 and a battery 30. That is, the vehicle 1 includes a first coolant circuit 40, a second coolant circuit 60, a refrigerant circuit 80, and a heating system 90.

[0012] The first coolant circuit 40 circulates the first coolant FW through the powertrain 20 and the radiator 50. In the first coolant circuit 40, heat exchange occurs between the first coolant FW and the powertrain 20, thereby cooling the powertrain 20. That is, the radiator 50 cools the first coolant FW, and, for example, a radiator fan (not shown) forcibly exchanges heat between the first coolant FW flowing through the radiator 50 and outside air, thereby cooling the first coolant FW. Then, the first coolant FW cooled by the radiator 50 is introduced into the powertrain 20, whereby heat is transferred from the powertrain 20 to the first coolant FW, thereby cooling the powertrain 20.

[0013] A water temperature sensor (not shown) is attached to the first coolant circuit 40 near the coolant outlet of the powertrain 20. The water temperature sensor detects a powertrain outlet water temperature TOP, which is the temperature of the first coolant FW flowing out from the powertrain 20. The powertrain outlet water temperature TOP is the temperature of the first coolant FW in the first coolant circuit 40, and in particular, is the temperature of the first coolant FW at the coolant outlet of the powertrain 20. The powertrain outlet water temperature TOP may be considered to be the temperature of the first coolant FW downstream of the powertrain 20 in the first coolant circuit 40. The powertrain outlet water temperature TOP may also be considered to be the temperature of the first coolant FW in the first coolant circuit 40 after absorbing heat from the powertrain 20 (in other words, warmed by the powertrain 20).

[0014] The second coolant circuit 60 circulates the second coolant SW through the chiller 70 and at least one of the powertrain 20 and the battery 30. In the second coolant circuit 60, heat exchange occurs between the second coolant SW and at least one of the powertrain 20 and the battery 30. Through this heat exchange, the second coolant SW recovers heat from at least one of the powertrain 20 and the battery 30, that is, cools at least one of the powertrain 20 and the battery 30. In other words, by being introduced into at least one of the powertrain 20 and the battery 30, the second coolant SW recovers heat from at least one of the powertrain 20 and the battery 30 and cools at least one of the powertrain 20 and the battery 30. Specifically, the second coolant circuit 60 introduces the second coolant SW cooled by the chiller 70 into at least one of the powertrain 20 and the battery 30. With this introduction, the second coolant circuit 60 recovers heat from at least one of the powertrain 20 and the battery 30 by using the second coolant SW, and cools at least one of the powertrain 20 and the battery 30 .

[0015] 1 , the second coolant circuit 60 includes a second coolant circuit 60(P) passing through the powertrain 20, a second coolant circuit 60(B) passing through the battery 30, and a control valve 62. The control valve 62 circulates the second coolant SW through at least one of the second coolant circuit 60(P) and the second coolant circuit 60(B) in accordance with a control signal CS from the circuit control device 10, which will be described later, i.e., introduces the second coolant SW into at least one of the second coolant circuit 60(P) and the second coolant circuit 60(B). Specifically, by introducing the second coolant SW cooled by the chiller 70 into the second coolant circuit 60(P), heat from the powertrain 20 is recovered by the second coolant SW, and the powertrain 20 is cooled by the second coolant SW. In addition, the second cooling water SW cooled by the chiller 70 is introduced into the second cooling water circuit 60 (B), so that the heat of the battery 30 is recovered by the second cooling water SW, and the battery 30 is cooled by the second cooling water SW.

[0016] A water temperature sensor (not shown) is attached to the second coolant circuit 60 near the coolant inlet of the battery 30. This water temperature sensor detects a battery inlet water temperature TIB, which is the temperature of the second coolant SW flowing into (introduced into) the battery 30. The battery inlet water temperature TIB is the temperature of the second coolant SW in the second coolant circuit 60, and in particular, is the temperature of the second coolant SW at the coolant inlet of the battery 30. The battery inlet water temperature TIB may be considered to be the temperature of the second coolant SW upstream of the battery 30 in the second coolant circuit 60. Alternatively, the battery inlet water temperature TIB may be considered to be the temperature of the second coolant SW in the second coolant circuit 60 before recovering heat from the battery 30 (i.e., before cooling the battery 30).

[0017] Furthermore, a water temperature sensor (not shown) is attached to the second coolant circuit 60 near the coolant outlet of the battery 30. The water temperature sensor detects a battery outlet water temperature TOB, which is the temperature of the second coolant SW flowing out from the battery 30. The battery outlet water temperature TOB is the temperature of the second coolant SW in the second coolant circuit 60, and in particular, the temperature of the second coolant SW at the coolant outlet of the battery 30. The battery outlet water temperature TOB may be considered to be the temperature of the second coolant SW downstream of the battery 30 in the second coolant circuit 60. The battery outlet water temperature TOB may also be considered to be the temperature of the second coolant SW after the second coolant circuit 60 has recovered heat from the battery 30 (i.e., after absorbing heat from the battery 30 and being heated by the battery 30).

[0018] The chiller 70 transfers heat from the second coolant SW circulating through the second coolant circuit 60 to the refrigerant RF circulating through the refrigerant circuit 80 by performing heat exchange between the second coolant SW circulating through the second coolant circuit 60 and the refrigerant RF. That is, the second coolant SW is cooled in the chiller 70, and the refrigerant RF is heated in the chiller 70. As described above, in the second coolant circuit 60, the second coolant SW recovers heat from at least one of the powertrain 20 and the battery 30, and cools at least one of the powertrain 20 and the battery 30. Then, the "heat from at least one of the powertrain 20 and the battery 30" recovered by the second coolant SW is transferred to the refrigerant RF in the chiller 70.

[0019] The refrigerant circuit 80 circulates the refrigerant RF between the chiller 70 and the heating system 90, and heat exchange between the chiller 70 (second coolant circuit 60) and the heating system 90 is achieved via the refrigerant RF. That is, in the refrigerant circuit 80, heat is transferred from the refrigerant RF to the heating system 90, and the heating system 90 recovers the heat of the refrigerant RF, while the refrigerant RF is cooled by the heating system 90. The refrigerant RF cooled by the heating system 90 is introduced into the chiller 70, whereby it absorbs heat from the second coolant SW circulating through the second coolant circuit 60, that is, it recovers heat from the second coolant SW (cools the second coolant SW). Furthermore, in the refrigerant circuit 80, the refrigerant RF heated by the chiller 70 (that is, by heat exchange with the second coolant SW) is introduced into the heating system 90, whereby it dissipates heat to the liquid (or gas) circulating within the heating system 90, that is, it heats the liquid. Therefore, the "heat of at least one of the powertrain 20 and the battery 30" recovered by the second coolant SW is transferred from the second coolant SW to the refrigerant RF in the chiller 70. Then, the "heat of at least one of the powertrain 20 and the battery 30" transferred to the refrigerant RF is further transferred from the refrigerant RF to the heating system 90 (the liquid (or gas) circulating within the heating system 90) and is used to heat the passenger compartment of the vehicle 1.

[0020] The heating system 90 is a so-called heat pump type heating device, and heats the passenger compartment of the vehicle 1. Specifically, the heating system 90 recovers heat from at least one of the powertrain 20 and the battery 30 by heat exchange between the refrigerant RF circulating through the refrigerant circuit 80 and a liquid (or gas) circulating within the heating system 90. The heating system 90 then uses the recovered "heat from at least one of the powertrain 20 and the battery 30" to heat the passenger compartment of the vehicle 1.

[0021] 2 is a diagram illustrating how heat from at least one of the powertrain 20 and the battery 30 is recovered by the second coolant SW circulating through the second coolant circuit 60, and the recovered heat is used to heat the passenger compartment of the vehicle 1. The circuit control device 10 transmits a control signal CS to the control valve 62, causing the control valve 62 to control the flow of the second coolant SW in the second coolant circuit 60. Specifically, the circuit control device 10 uses the control signal CS to cause the control valve 62 to introduce the second coolant SW into at least one of the second coolant circuit 60(P) and the second coolant circuit 60(B). In other words, the circuit control device 10 controls the control valve 62 to introduce the second coolant SW into at least one of the powertrain 20 and the battery 30. Through this control, the circuit control device 10 recovers heat from at least one of the powertrain 20 and the battery 30 using the second coolant SW, and cools at least one of the powertrain 20 and the battery 30 .

[0022] In the illustrated example, in the second coolant circuit 60, the powertrain 20 and the battery 30 are provided downstream of the chiller 70, which is provided upstream. Furthermore, in the second coolant circuit 60, the powertrain 20 and the battery 30 are provided in parallel to the chiller 70. In the second coolant circuit 60, a control valve 62 connects a second coolant circuit 60(P) passing through the powertrain 20 with a second coolant circuit 60(B) passing through the battery 30. In the illustrated example, the control valve 62 connects the second coolant circuit 60(P) and the second coolant circuit 60(B), which are provided in parallel to the chiller 70, and connects, for example, the downstream side of the powertrain 20 with the downstream side of the battery 30. In addition, in the illustrated example, a pump 64(P) is provided upstream of the powertrain 20 in the second coolant circuit 60(P), and a pump 64(B) is provided upstream of the battery 30 in the second coolant circuit 60(B).

[0023] The circuit control device 10 controls the control valve 62 using the control signal CS to introduce the second coolant SW only into the second coolant circuit 60(P), that is, to circulate the second coolant SW only between the powertrain 20 and the chiller 70. For example, the circuit control device 10 controls the control valve 62 by outputting a control signal CS(P) to the control valve 62 instructing the control valve 62 to "close the flow of the second coolant SW from the battery 30 to the chiller 70 and open the flow of the second coolant SW from the powertrain 20 to the chiller 70." By this control, the circuit control device 10 can introduce the second coolant SW only into the second coolant circuit 60(P), that is, to introduce the second coolant SW only into the powertrain 20. In conjunction with this control, the circuit control device 10 may operate the pump 64(P) and stop the pump 64(B). The circuit control device 10 controls the control valve 62 to introduce the second cooling water SW only into the powertrain 20, thereby allowing the second cooling water SW to recover only the heat of the powertrain 20 and cool only the powertrain 20.

[0024] Furthermore, the circuit control device 10 controls the control valve 62 using the control signal CS to introduce the second coolant SW only into the second coolant circuit 60(B), i.e., to circulate the second coolant SW only between the battery 30 and the chiller 70. For example, the circuit control device 10 controls the control valve 62 by outputting a control signal CS(B) to the control valve 62 instructing the control valve 62 to "close the flow of the second coolant SW from the powertrain 20 to the chiller 70 and open the flow of the second coolant SW from the battery 30 to the chiller 70." Through this control, the circuit control device 10 can introduce the second coolant SW only into the second coolant circuit 60(B), i.e., to introduce the second coolant SW only into the battery 30. In conjunction with this control, the circuit control device 10 may operate the pump 64(B) and stop the pump 64(P). The circuit control device 10 controls the control valve 62 to introduce the second cooling water SW only to the battery 30, so that the second cooling water SW can recover only the heat of the battery 30 and cool only the battery 30.

[0025] Furthermore, the circuit control device 10 controls the control valve 62 using the control signal CS to introduce the second coolant SW into both the second coolant circuit 60(P) and the second coolant circuit 60(B). That is, the circuit control device 10 can circulate the second coolant SW between the chiller 70 and each of the powertrain 20 and the battery 30. For example, the circuit control device 10 controls the control valve 62 by outputting a control signal CS(P&B) to the control valve 62 that instructs the control valve 62 to "open the flow of the second coolant SW from the powertrain 20 to the chiller 70 and open the flow of the second coolant SW from the battery 30 to the chiller 70." Through this control, the circuit control device 10 can introduce the second coolant SW into both the second coolant circuit 60(P) and the second coolant circuit 60(B), that is, the circuit control device 10 can introduce the second coolant SW into both the powertrain 20 and the battery 30. In the illustrated example, the control signal CS(P&B) causes the second coolant SW to be introduced in parallel to the powertrain 20 and the battery 30. In conjunction with this control, the circuit control device 10 may operate both the pump 64(B) and the pump 64(P). The circuit control device 10 controls the control valve 62 to introduce the second coolant SW to both the powertrain 20 and the battery 30, thereby allowing the second coolant SW to recover heat from both the powertrain 20 and the battery 30 and cool both the powertrain 20 and the battery 30.

[0026] The second coolant SW that has recovered heat from at least one of the powertrain 20 and the battery 30 (in other words, absorbed heat from at least one of them) exchanges heat in the chiller 70 with the refrigerant RF circulating through the refrigerant circuit 80. Furthermore, heat is exchanged between the refrigerant RF circulating through the refrigerant circuit 80 and a liquid (or gas) circulating in the heating system 90 (particularly, the heater 96). Through these heat exchanges, the heating system 90 uses the heat of at least one of the powertrain 20 and the battery 30 to heat the passenger compartment of the vehicle 1.

[0027] 2 , the heating system 90 includes a compressor 92, a condenser 94, and a heater 96. The refrigerant RF that absorbs heat from the second coolant SW in the chiller 70 is compressed by, for example, the compressor 92 to become a high-temperature, high-pressure gas. Then, in the condenser 94, the refrigerant RF that has been heated to a high temperature and high pressure by the compressor 92 exchanges heat with a liquid (or gas) circulating in a heater 96 (heating circuit), thereby warming (heating) the liquid (or gas) and cooling the refrigerant RF. The heater 96 warms air (outside air) using the liquid (or gas) heated by heat exchange with the refrigerant RF, and the warmed air is blown into the vehicle cabin as hot air from, for example, at least one of a front defroster duct, a face register, and a foot register.

[0028] Here, the temperature (battery temperature TB) of the battery 30 rises due to charging (e.g., rapid charging), etc. If the battery temperature TB is higher than a temperature range (appropriate temperature range STR) suitable for charging the battery 30, charging of the battery 30 is restricted until the battery temperature TB falls to a temperature included in the appropriate temperature range STR. For example, the next rapid charge or charging using regenerative power from the drive motor is restricted until the battery temperature TB falls to a temperature included in the appropriate temperature range STR.

[0029] Therefore, the circuit control device 10 cools the battery 30 using the second coolant SW to maintain the battery temperature TB within the appropriate temperature range STR, thereby preventing deterioration of the chargeability of the battery 30. In particular, when the battery temperature TB is high, the circuit control device 10 cools the battery 30 through heat exchange between the second coolant SW and the battery 30, and uses the heat of the battery 30 recovered by the second coolant SW to heat the passenger compartment of the vehicle 1. Through this control, the circuit control device 10 can save power consumed for heating the passenger compartment. Furthermore, by appropriately cooling the battery 30 using the second coolant SW, the circuit control device 10 maintains the battery temperature TB within a temperature range (appropriate temperature range STR) suitable for charging the battery 30, thereby maintaining good chargeability of the battery 30. The circuit control device 10 cools the battery 30 using the second coolant SW, thereby maintaining good charging performance of the battery 30, and by using the heat from the battery 30 to heat the passenger compartment, it is possible to save on the electricity required for heating, thereby improving the power consumption of the vehicle 1.

[0030] Here, the specific heat of the battery 30 is smaller than the specific heat of the powertrain 20, that is, the thermal resistance of the battery 30 is greater than that of the powertrain 20. Therefore, the transfer of heat from the battery 30 to the second coolant SW is slow, and for example, it takes time for the battery outlet water temperature TOB to increase, resulting in a state where the battery outlet water temperature TOB is low. Furthermore, if the amount of heat that can be recovered by the chiller 70 (in other words, the heat that can be recovered by the second coolant SW) is small, it naturally takes time to heat the vehicle cabin using the heat recovered by the chiller 70.

[0031] Therefore, the circuit control device 10 also utilizes the powertrain 20, which has a larger specific heat than the battery 30, i.e., a smaller thermal resistance than the battery 30, as a heat source for heating the passenger compartment. Specifically, the circuit control device 10 recovers heat not only from the battery 30 but also from the powertrain 20 using the second coolant SW, and uses the recovered heat from both the battery 30 and the powertrain 20 to heat the passenger compartment of the vehicle 1.

[0032] Because the powertrain 20 has a smaller thermal resistance than the battery 30, heat transfer from the powertrain 20 to the second coolant SW is faster than heat transfer from the battery 30 to the second coolant SW. Therefore, by introducing the second coolant SW to both the powertrain 20 and the battery 30 in the second coolant circuit 60, the circuit control device 10 can warm (heat) the second coolant SW more quickly than when introducing the second coolant SW only to the battery 30. The circuit control device 10 can quickly heat the passenger compartment of the vehicle 1 by utilizing the heat recovered from both the powertrain 20 and the battery 30 by the second coolant SW. The circuit control device 10 can quickly heat the passenger compartment of the vehicle 1 by recovering heat not only from the battery 30 but also from the powertrain 20 and using the recovered heat to heat the passenger compartment of the vehicle 1, thereby quickly heating the passenger compartment and further saving power consumed during heating.

[0033] However, if the battery 30 cannot be cooled by the second coolant SW, the circuit control device 10 does not introduce the second coolant SW into the battery 30. Furthermore, if introducing the second coolant SW into both the powertrain 20 and the battery 30 would deteriorate the charge acceptance of the battery 30, the circuit control device 10 introduces the second coolant SW only into the battery 30 in the second coolant circuit 60. Specifically, if the battery temperature TB is higher than the upper limit temperature (charge acceptance temperature TA) of the appropriate temperature range STR, the circuit control device 10 introduces the second coolant SW only into the battery 30, thereby cooling only the battery 30 with the second coolant SW. By introducing the second coolant SW only into the battery 30, the circuit control device 10 can cool the battery 30 more quickly than if the second coolant SW were introduced into both the powertrain 20 and the battery 30. The circuit control device 10 can prevent a deterioration in the charge acceptance of the battery 30 by quickly cooling the battery 30 with the second coolant SW. The circuit control device 10, which has been outlined above, will be described in detail below with reference to Figures 3 to 6.

[0034] §2 Configuration Example [Hardware Configuration] Fig. 3 schematically illustrates an example of the hardware configuration of the circuit control device 10 according to this embodiment. As shown in Fig. 3, the circuit control device 10 according to this embodiment is a computer to which a control unit 11, a storage unit 12, a communication interface 13, an external interface 14, an input device 15, an output device 16, and a drive 17 are electrically connected. Note that in Fig. 3, the communication interface and the external interface are referred to as a "communication I / F" and an "external I / F."

[0035] The control unit 11 includes a hardware processor such as a central processing unit (CPU), a random access memory (RAM), and a read-only memory (ROM), and is configured to execute information processing based on programs and various data. The CPU is an example of a processor resource. The storage unit 12 is an example of a memory resource, and is configured, for example, with a hard disk drive or a solid-state drive. In this embodiment, the storage unit 12 stores various information such as a circuit control program 120 and charge acceptance temperature information 122.

[0036] The circuit control program 120 is a program for causing a processor (for example, the CPU of the circuit control device 10) to execute information processing ( FIG. 6 ) described below for recovering heat from at least one of the powertrain 20 and the battery 30 to be used for heating the passenger compartment of the vehicle 1. The circuit control program 120 includes a series of instructions for the information processing.

[0037] The charge acceptance temperature information 122 is information indicating the charge acceptance temperature TA. The charge acceptance temperature TA is an example of the “predetermined charge acceptance temperature” of the present invention, and is, for example, the upper limit temperature of the appropriate temperature range STR, which is a temperature range suitable for charging the battery 30.

[0038] The communication interface 13 is, for example, a wired local area network (LAN) module, a wireless LAN module, or the like, and is an interface for performing wired or wireless communication via a network. The communication interface 13 may also be an interface for performing communication via a controller area network (CAN) or other in-vehicle LAN. The circuit control device 10 may use the communication interface 13 to perform data communication with other information processing devices via a network. For example, the circuit control device 10 communicates (transmits and receives information) with the second coolant circuit 60 (particularly the control valve 62 of the second coolant circuit 60), the powertrain control module 22, the battery control module 32, the heating control module 98, and the like via the communication interface 13. The powertrain control module 22, the battery control module 32, and the heating control module 98 will be described in detail below. The external interface 14 is, for example, a universal serial bus (USB) port, a dedicated port, or the like, and is an interface for connecting to an external device. The type and number of external interfaces 14 may be selected appropriately depending on the type and number of external devices to be connected.

[0039] For example, the circuit control device 10 is connected to another information processing device via at least one of the communication interface 13 and the external interface 14, and performs the following communications with the other information processing device. That is, the circuit control device 10 is connected to the powertrain control module 22 and acquires the powertrain outlet water temperature TOP from the powertrain control module 22. The circuit control device 10 is connected to the battery control module 32 and acquires the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB from the battery control module 32. The circuit control device 10 is connected to the heating control module 98 and acquires a heat recovery request instruction RI from the heating control module 98. The circuit control device 10 is connected to the second coolant circuit 60 (particularly, the control valve 62 of the second coolant circuit 60) and outputs a control signal CS to the control valve 62. The heat recovery request instruction RI will be described in detail below.

[0040] The input device 15 is a device for inputting information, such as a mouse or a keyboard. The output device 16 is a device for outputting information, such as a display or a speaker. An operator such as a user can operate the circuit control device 10 by using the input device 15 and the output device 16.

[0041] The drive 17 is, for example, a CD drive, a DVD drive, or the like, and is a drive device for reading various information, such as programs, stored in a storage medium 91. The storage medium 91 is a medium that stores information, such as programs, electrically, magnetically, optically, mechanically, or chemically, so that a computer or other device, machine, or the like can read the stored information. At least one of the circuit control program 120 and the charge acceptance temperature information 122 may be stored in the storage medium 91. The circuit control device 10 may acquire at least one of the circuit control program 120 and the charge acceptance temperature information 122 from the storage medium 91. Note that FIG. 3 illustrates a disk-type storage medium, such as a CD or DVD, as an example of the storage medium 91. However, the type of the storage medium 91 is not limited to a disk-type medium and may be other types of storage medium. Examples of storage media other than disk-type storage mediums include semiconductor memories, such as flash memories. The type of the drive 17 may be selected arbitrarily depending on the type of the storage medium 91.

[0042] Note that, with regard to the specific hardware configuration of the circuit control device 10, components may be omitted, replaced, or added as appropriate depending on the embodiment. For example, the processor resource may include multiple hardware processors. The hardware processor may be a microprocessor, a field-programmable gate array (FPGA), a digital signal processor (DSP), or the like. The storage unit 12 may be configured with RAM and ROM included in the control unit 11. At least one of the communication interface 13, the external interface 14, the input device 15, the output device 16, and the drive 17 may be omitted. The circuit control device 10 may be configured with multiple computers. In this case, the hardware configurations of the computers may or may not be identical. Furthermore, the circuit control device 10 may be an information processing device designed specifically for the service provided, as well as a general-purpose server device, a PC (Personal Computer), or the like.

[0043] [Software Configuration] Fig. 4 schematically illustrates an example of the software configuration of the circuit control device 10 according to this embodiment. The control unit 11 of the circuit control device 10 loads the circuit control program 120 stored in the storage unit 12 onto the RAM. The control unit 11 then uses the CPU to interpret and execute instructions included in the circuit control program 120 loaded onto the RAM to control each component. As a result, as shown in Fig. 4, the circuit control device 10 according to this embodiment operates as a computer including an acquisition unit 110, a determination unit 130, and a signal generation unit 140 as software modules. In other words, in this embodiment, each software module of the circuit control device 10 is realized by the control unit 11 (CPU).

[0044] The acquisition unit 110 acquires the powertrain outlet water temperature TOP, the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB, and notifies the determination unit 130 of the acquired powertrain outlet water temperature TOP, the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB.

[0045] For example, the acquisition unit 110 acquires the powertrain outlet water temperature TOP from the powertrain control module 22 that manages the powertrain 20 and the first coolant circuit 40. In the example shown in Fig. 4 , the powertrain control module 22 acquires the powertrain outlet water temperature TOP from the powertrain 20 and outputs the acquired powertrain outlet water temperature TOP to the acquisition unit 110. The powertrain control module 22 may acquire the powertrain outlet water temperature TOP from the first coolant circuit 40 and output the acquired powertrain outlet water temperature TOP to the acquisition unit 110.

[0046] For example, the acquisition unit 110 acquires the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB from the battery control module 32 that manages the battery 30 and the second coolant circuit 60. In the example shown in Fig. 4 , the battery control module 32 acquires the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB from the battery 30, and outputs the acquired battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB to the acquisition unit 110. The battery control module 32 may acquire the battery inlet water temperature TIB and the battery outlet water temperature TOB from the second coolant circuit 60, and output the acquired battery inlet water temperature TIB and the battery outlet water temperature TOB to the acquisition unit 110.

[0047] The acquisition unit 110 may further acquire a heat recovery request instruction RI from a heating control module 98 that manages the heating system 90. For example, the heating control module 98 acquires the temperature of the passenger compartment of the vehicle 1 (compartment temperature TC) from the heating system 90. If the acquired passenger compartment temperature TC is lower than a heating temperature (set temperature) set by an occupant of the vehicle 1, for example, the heating control module 98 outputs a heat recovery request instruction RI to the circuit control device 10 (particularly the acquisition unit 110). The heat recovery request instruction RI is an instruction requesting heating of the passenger compartment of the vehicle 1. As described above, in the vehicle 1, heating of the passenger compartment of the vehicle 1 is performed using heat recovered from at least one of the powertrain 20 and the battery 30. Therefore, the heat recovery request instruction RI requesting heating of the passenger compartment can be considered as an instruction requesting the circuit control device 10 to recover heat from at least one of the powertrain 20 and the battery 30. When the acquisition unit 110 acquires the heat recovery request instruction RI from the heating control module 98, the acquisition unit 110 may notify the determination unit 130 of the acquired heat recovery request instruction RI.

[0048] The determination unit 130 executes a determination process and notifies the signal generation unit 140 of the result of the determination process. For example, the determination unit 130 first determines whether the acquisition unit 110 has acquired a heat recovery request instruction RI from the heating control module 98. If the determination unit 130 determines that the acquisition unit 110 has acquired a heat recovery request instruction RI, the determination unit 130 further executes various determination processes using the powertrain outlet water temperature TOP, battery temperature TB, battery inlet water temperature TIB, and battery outlet water temperature TOB acquired by the acquisition unit 110. In the illustrated example, the determination unit 130 includes a first determination unit 132, a second determination unit 134, a third determination unit 136, and a fourth determination unit 138 as functional blocks (software modules) that execute each of the above-described various determination processes.

[0049] The first determination unit 132 compares the battery temperature TB with the charge acceptance temperature TA, and in particular determines whether the battery temperature TB is equal to or lower than the charge acceptance temperature TA. For example, the first determination unit 132 references the storage unit 12 to acquire the charge acceptance temperature information 122. The first determination unit 132 compares the charge acceptance temperature TA indicated by the acquired charge acceptance temperature information 122 with the battery temperature TB, and notifies the signal generation unit 140 of the result of the comparison. The first determination unit 132 may notify the signal generation unit 140 of the determination result as to whether the battery temperature TB is equal to or lower than the charge acceptance temperature TA.

[0050] The second determination unit 134 compares the battery temperature TB with the battery inlet water temperature TIB, and in particular determines whether the battery temperature TB is higher than the battery inlet water temperature TIB. The second determination unit 134 then notifies the signal generation unit 140 of the result of the comparison. The second determination unit 134 may also notify the signal generation unit 140 of the determination result of whether the battery temperature TB is higher than the battery inlet water temperature TIB.

[0051] The third determination unit 136 compares the powertrain outlet water temperature TOP with the battery outlet water temperature TOB, and in particular determines whether the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB. The third determination unit 136 then notifies the signal generation unit 140 of the result of the comparison. The third determination unit 136 may also notify the signal generation unit 140 of the determination result as to whether the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB.

[0052] The fourth determination unit 138 compares the powertrain outlet water temperature TOP with the battery temperature TB, and in particular determines whether the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB. The fourth determination unit 138 then notifies the signal generation unit 140 of the result of the comparison. The fourth determination unit 138 may also notify the signal generation unit 140 of the determination result as to whether the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB.

[0053] The signal generating unit 140 generates a control signal CS in accordance with the result of the determination process by the determining unit 130, and outputs the generated control signal CS to the second coolant circuit 60 (particularly, the control valve 62 of the second coolant circuit 60). The control signal CS is a signal that causes the control valve 62 to control the flow of the second coolant SW in the second coolant circuit 60, and particularly, is a signal that causes the second coolant SW to be introduced into at least one of the powertrain 20 and the battery 30.

[0054] (When the battery temperature is higher than the charge acceptance temperature) When the first judgment unit 132 judges that the battery temperature TB is higher than the charge acceptance temperature TA, the signal generation unit 140 generates a control signal CS(B) that causes the second coolant SW to be introduced only into the battery 30, and outputs the generated control signal CS(B) to the control valve 62.

[0055] As described above, when the battery temperature TB is higher than the charge acceptance temperature TA, the charge acceptance of the battery 30 deteriorates. Therefore, the signal generating unit 140 generates the control signal CS(B) for introducing the second coolant SW only into the battery 30, and introduces the second coolant SW only into the battery 30. By introducing the second coolant SW only into the battery 30, the signal generating unit 140 can cool the battery 30 more quickly than when the second coolant SW is introduced into both the powertrain 20 and the battery 30, and can prevent the charge acceptance of the battery 30 from deteriorating.

[0056] (When the battery temperature is equal to or lower than the charge acceptance temperature and equal to or lower than the battery inlet water temperature) When the first determination unit 132 determines that the battery temperature TB is equal to or lower than the charge acceptance temperature TA and the second determination unit 134 determines that the battery temperature TB is equal to or lower than the battery inlet water temperature TIB, the signal generation unit 140 generates the following control signal CS. That is, the signal generation unit 140 generates a control signal CS(P) that introduces the second coolant SW only into the powertrain 20 and outputs the generated control signal CS(P) to the control valve 62.

[0057] When the battery temperature TB is equal to or lower than the charge acceptance temperature TA, there is little need to introduce the second coolant SW only into the battery 30 to rapidly cool the battery 30. Furthermore, when the battery temperature TB is equal to or lower than the battery inlet water temperature TIB, the battery 30 cannot be cooled by the second coolant SW. Therefore, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA and the battery temperature TB is equal to or lower than the battery inlet water temperature TIB, the signal generating unit 140 introduces the second coolant SW only into the powertrain 20. Even when the second coolant SW cannot cool the battery 30, the signal generating unit 140 recovers heat from the powertrain 20 using the second coolant SW, and the recovered heat is used to heat the passenger compartment of the vehicle 1, thereby saving the power required for heating. In particular, as described above, the powertrain 20 has a low thermal resistance, and the heat from the powertrain 20 is quickly transferred to the second coolant SW. Therefore, even when the battery 30 cannot be cooled by the second cooling water SW, the signal generating unit 140 can introduce the second cooling water SW into the powertrain 20, quickly recover the heat of the powertrain 20 by the second cooling water SW, and quickly heat the passenger compartment.

[0058] (When the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, and the powertrain outlet water temperature is equal to or lower than the battery outlet water temperature) When the first determination unit 132 determines that the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the second determination unit 134 determines that the battery temperature TB is higher than the battery inlet water temperature TIB, and the third determination unit 136 determines that the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the signal generation unit 140 generates the following control signal CS. That is, the signal generation unit 140 generates a control signal CS(B) that introduces the second coolant SW only into the battery 30, and outputs the generated control signal CS(B) to the control valve 62.

[0059] When the battery temperature TB is higher than the battery inlet water temperature TIB, it is possible to cool the battery 30 with the second coolant SW. However, when the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the temperature of the powertrain 20 is considered to be sufficiently low. In particular, as described above, the powertrain 20 has a large specific heat, i.e., a small thermal resistance. Therefore, in the first coolant circuit 40, heat from the powertrain 20 is considered to be rapidly transferred to the first coolant FW. Therefore, when the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the temperature of the powertrain 20 is likely to be equal to or lower than the battery outlet water temperature TOB. In such a situation, even if the second coolant SW is introduced into both the powertrain 20 and the battery 30, it is difficult for the second coolant SW to recover the heat from the powertrain 20. In fact, if the second coolant SW is introduced into both the powertrain 20 and the battery 30 when the temperature of the powertrain 20 is sufficiently low, the second coolant SW may even be cooled by the powertrain 20. Furthermore, if the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the temperature of the battery 30 is considered to be sufficiently high. In particular, as described above, the battery 30 has a low specific heat, i.e., a high thermal resistance. Nevertheless, if the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, it is considered that the temperature of the battery 30 is sufficiently high, and the second coolant SW is able to recover heat from the high-temperature battery 30. In such a situation, if the second coolant SW is introduced into both the low-temperature powertrain 20 with low thermal resistance and the high-temperature battery 30 with high thermal resistance, there is even a possibility that heat will be transferred from the high-temperature battery 30 (and the second coolant SW) to the powertrain 20. Therefore, in such a situation, introducing the second cooling water SW only into the battery 30 allows the second cooling water SW to recover the heat from the high-temperature battery 30 more efficiently than introducing the second cooling water SW into both the powertrain 20 and the battery 30.

[0060] Therefore, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the battery temperature TB is higher than the battery inlet water temperature TIB, and the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the signal generating unit 140 introduces the second coolant SW only into the battery 30. As described above, when the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, it is considered difficult for the second coolant SW to recover heat used to heat the passenger compartment of the vehicle 1 from the powertrain 20. When the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, introducing the second coolant SW into the powertrain 20 may even hinder heat recovery by the second coolant SW. Therefore, when the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, the signal generating unit 140 introduces the second coolant SW only into the battery 30. By introducing the second coolant SW into the battery 30, the signal generating unit 140 can recover heat from the battery 30 that is used to heat the passenger compartment of the vehicle 1. Furthermore, by introducing the second coolant SW into the battery 30, the signal generating unit 140 can cool the battery 30 and prevent the charge acceptance of the battery 30 from deteriorating.

[0061] (When the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, and the powertrain outlet water temperature is higher than the battery outlet water temperature) When the first determination unit 132 determines that the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the second determination unit 134 determines that the battery temperature TB is higher than the battery inlet water temperature TIB, and the third determination unit 136 determines that the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the signal generation unit 140 generates the following control signal CS. That is, the signal generation unit 140 generates a control signal CS (P&B) that introduces second coolant SW to both the powertrain 20 and the battery 30, and outputs the generated control signal CS (P&B) to the control valve 62.

[0062] When the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the temperature of the powertrain 20 is also higher than the battery outlet water temperature TOB. Therefore, the signal generating unit 140 can recover heat from the powertrain 20 using the second coolant SW, and the recovered heat can be used to heat the passenger compartment of the vehicle 1, thereby saving on the electricity required for heating. In particular, as described above, the powertrain 20 has low thermal resistance, and the heat from the powertrain 20 is quickly transferred to the second coolant SW. Therefore, by introducing the second coolant SW into the powertrain 20, the signal generating unit 140 can quickly recover the heat from the powertrain 20 using the second coolant SW, thereby quickly heating the passenger compartment of the vehicle 1.

[0063] Furthermore, when "the battery temperature TB is higher than the battery inlet water temperature TIB," the battery 30 can be cooled by the second coolant SW. Therefore, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the battery temperature TB is higher than the battery inlet water temperature TIB, and the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the signal generating unit 140 introduces the second coolant SW into both the powertrain 20 and the battery 30. Through this control, the signal generating unit 140 recovers heat used to heat the passenger compartment of the vehicle 1 from both the powertrain 20 and the battery 30 by the second coolant SW, thereby efficiently heating the passenger compartment and saving the power required for heating. Furthermore, by cooling the battery 30 with the second coolant SW, the signal generating unit 140 can prevent the charge acceptance of the battery 30 from deteriorating. By controlling the flow of the second coolant SW in the second coolant circuit 60, the signal generating unit 140 can achieve both efficient heating of the passenger compartment of the vehicle 1 and improved charging acceptance of the battery 30 by cooling the battery 30, thereby improving the electric power consumption of the vehicle 1.

[0064] (Control Using Comparison Result Between Powertrain Outlet Water Temperature and Battery Temperature) The signal generating unit 140 may further generate the control signal CS using the determination result (comparison result) of the fourth determining unit 138. That is, when generating the control signal CS, the signal generating unit 140 may further take into consideration whether the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB.

[0065] (When the powertrain outlet water temperature is higher than the battery temperature) When the fourth determination unit 138 determines that the powertrain outlet water temperature TOP is higher than the battery temperature TB, the signal generation unit 140 may generate the following control signal CS. That is, the signal generation unit 140 may generate a control signal CS(B) that causes the second coolant SW to be introduced only into the battery 30. The signal generation unit 140 outputs the generated control signal CS(B) to the control valve 62.

[0066] When the powertrain outlet water temperature TOP is higher than the battery temperature TB, the temperature of the powertrain 20 from which heat is recovered by the first coolant FW (i.e., cooled by the first coolant FW) is naturally higher than the battery temperature TB. In such a situation, if the second coolant SW is introduced into both the powertrain 20 and the battery 30, it may be difficult for the second coolant SW to efficiently cool the battery 30. For example, if the second coolant SW is introduced into both the high-temperature powertrain 20 and the low-temperature battery 30, the second coolant SW in the second coolant circuit 60 may be heated by heat exchange with the high-temperature powertrain 20, and may not be able to cool the battery 30. Furthermore, if the second coolant SW is introduced into both the high-temperature powertrain 20 and the low-temperature battery 30 in the second coolant circuit 60, heat may be transferred from the high-temperature powertrain 20 to the low-temperature battery 30 via the second coolant SW. If such a heat transfer occurs, the battery 30 will not be cooled by the second coolant SW, but will instead be warmed (heated) by the second coolant SW. In particular, as described above, the powertrain 20 has a smaller thermal resistance than the battery 30, and heat transfer from the powertrain 20 to the second coolant SW is faster than heat transfer from the battery 30 to the second coolant SW. Therefore, the second coolant SW introduced into both the high-temperature powertrain 20 and the low-temperature battery 30 will be quickly heated by heat exchange with the high-temperature powertrain 20, making it difficult to efficiently cool the battery 30.

[0067] As described above, when the powertrain outlet water temperature TOP is higher than the battery temperature TB, if the second coolant SW is introduced into both the powertrain 20 and the battery 30, it may be difficult to cool the battery 30 with the second coolant SW. Therefore, when the powertrain outlet water temperature TOP is higher than the battery temperature TB, the signal generating unit 140 introduces the second coolant SW only into the battery 30. For example, in FIG. 5 , in the first case (a situation in which the powertrain outlet water temperature TOP is higher than the battery temperature TB), the signal generating unit 140 introduces the second coolant SW only into the battery 30. By introducing the second coolant SW only into the battery 30, the signal generating unit 140 recovers only the heat of the battery 30 with the second coolant SW and cools only the battery 30. By performing such control, the signal generating unit 140 can cool the battery 30 using the second cooling water SW, avoiding the situation where the second cooling water SW is heated by heat exchange with the high-temperature powertrain 20, making it impossible to cool the battery 30 using the second cooling water SW.

[0068] (When the powertrain outlet water temperature is equal to or lower than the battery temperature) When the fourth determination unit 138 determines that the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB, the signal generation unit 140 may generate the following control signal CS. That is, the signal generation unit 140 may generate a control signal CS(P&B) that introduces the second coolant SW into both the powertrain 20 and the battery 30. The signal generation unit 140 outputs the generated control signal CS(P&B) to the control valve 62.

[0069] As described above, if the powertrain outlet water temperature TOP is higher than the battery temperature TB, introducing the second coolant SW into both the powertrain 20 and the battery 30 may make it difficult to efficiently cool the battery 30 with the second coolant SW. On the other hand, if the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB, the second coolant SW can cool the battery 30 even if it is introduced into both the powertrain 20 and the battery 30. Therefore, when the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB, the signal generating unit 140 introduces the second coolant SW into both the powertrain 20 and the battery 30. For example, in FIG. 5 , in the second case (where the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB), the signal generating unit 140 introduces the second coolant SW into both the powertrain 20 and the battery 30. The signal generating unit 140 introduces the second coolant SW into both the powertrain 20 and the battery 30, thereby recovering heat from both the powertrain 20 and the battery 30 with the second coolant SW and cooling the battery 30. Through this control, the signal generating unit 140 recovers heat used to heat the passenger compartment of the vehicle 1 from both the powertrain 20 and the battery 30 with the second coolant SW, thereby efficiently heating the passenger compartment and saving the power required for heating. Furthermore, by cooling the battery 30 with the second coolant SW, the signal generating unit 140 can prevent a deterioration in the charge acceptance of the battery 30. By controlling the flow of the second coolant SW in the second coolant circuit 60, the signal generating unit 140 can achieve both efficient heating of the passenger compartment and improved charge acceptance of the battery 30 by cooling the battery 30, thereby improving the power consumption of the vehicle 1.

[0070] As described above, when the battery temperature TB is equal to or lower than the battery inlet water temperature TIB, the battery 30 cannot be cooled by the second coolant SW. Furthermore, when the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB, it is difficult to recover heat from the powertrain 20 by the second coolant SW. Furthermore, when the battery temperature TB is higher than the charge acceptance temperature TA, it is necessary to cool the battery 30 by the second coolant SW as quickly as possible. Therefore, it is desirable for the signal generating unit 140 to generate the control signal CS(P&B) when the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the battery temperature TB is higher than the battery inlet water temperature TIB, the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, and the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB.

[0071] In the vehicle 1, the powertrain outlet water temperature TOP may be controlled by, for example, the radiator 50 so that it is equal to or lower than a predetermined threshold temperature (the "powertrain outlet water temperature threshold" illustrated in FIG. 5 ). The "reference temperature" in FIG. 5 is a temperature that is lower than the charge acceptance temperature TA by a predetermined temperature (e.g., 10°C). When the battery temperature TB is lower than the reference temperature, the signal generating unit 140 may introduce the second coolant SW into both the powertrain 20 and the battery 30. When the battery temperature TB is lower than the reference temperature, for example, when the battery temperature TB is a sufficiently low temperature that is included in the "temperature range suitable for charging the battery 30 (appropriate temperature range STR)," there is little need to rapidly cool the battery 30. In such a case, the signal generating unit 140 may recover heat from both the powertrain 20 and the battery 30 to be used for heating the passenger compartment of the vehicle 1. That is, the signal generating unit 140 may introduce the second coolant SW into both the powertrain 20 and the battery 30, and recover heat from both the powertrain 20 and the battery 30 using the second coolant SW.

[0072] So far, an example has been described in which the signal generating unit 140 generates the control signal CS when the determination unit 130 determines that the acquisition unit 110 has acquired the heat recovery request instruction RI from the heating control module 98. That is, when the determination unit 130 determines that the acquisition unit 110 has acquired the heat recovery request instruction RI, the signal generating unit 140 generates the control signal CS in accordance with at least one of the determination results (comparison results) of the first determination unit 132, the second determination unit 134, the third determination unit 136, and the fourth determination unit 138. Here, for example, when the determination unit 130 determines that the acquisition unit 110 has not acquired the heat recovery request instruction RI, the signal generating unit 140 does not need to generate the control signal CS. That is, when heating of the passenger compartment of the vehicle 1 is not necessary, the circuit control device 10 does not need to perform the above-described process of recovering heat to be used for heating from at least one of the powertrain 20 and the battery 30. However, even when heating of the passenger compartment of the vehicle 1 is not required, the circuit control device 10 can cool the battery 30, for example, by introducing the second cooling water SW into the battery 30 to cool the battery 30.

[0073] §3 Operation Example Figure 6 is a flowchart showing an example of the processing procedure of the circuit control device 10 according to this embodiment. The processing procedure described below is an example of the processing procedure of the circuit control method PM that causes a processor (e.g., the CPU of the circuit control device 10) to execute a process of "recovering heat used to heat the passenger compartment of the vehicle 1 from at least one of the powertrain 20 and the battery 30." However, the processing procedure described below is merely an example, and each step may be modified as much as possible. Furthermore, steps may be omitted, replaced, or added to the processing procedure described below as appropriate depending on the embodiment.

[0074] (Step S110) In step S110, the control unit 11 operates as the determination unit 130 and determines whether waste heat recovery is necessary. That is, the control unit 11 determines whether heat needs to be recovered from at least one of the powertrain 20 and the battery 30 so that the passenger compartment of the vehicle 1 can be heated. For example, the control unit 11 determines whether the acquisition unit 110 has acquired a heat recovery request instruction RI from the heating control module 98. When the control unit 11 confirms that the acquisition unit 110 has acquired a heat recovery request instruction RI, the control unit 11 determines that waste heat recovery is necessary (Yes in step S110) and proceeds to step S120. When the control unit 11 confirms that the acquisition unit 110 has not acquired a heat recovery request instruction RI, the control unit 11 determines that waste heat recovery is not necessary (No in step S110) and ends the process.

[0075] (Step S120) In step S120, the control unit 11 operates as the acquisition unit 110 and acquires the powertrain outlet water temperature TOP, the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB. For example, the control unit 11 acquires the powertrain outlet water temperature TOP from the powertrain control module 22. The control unit 11 also acquires the battery temperature TB, the battery inlet water temperature TIB, and the battery outlet water temperature TOB from the battery control module 32.

[0076] (Step S130) In step S130, the control unit 11 operates as the determination unit 130 (particularly, the first determination unit 132) and determines whether the battery temperature TB acquired in step S120 is higher than the charge acceptance temperature TA. For example, the control unit 11 refers to the storage unit 12 to acquire the charge acceptance temperature information 122. The control unit 11 compares the charge acceptance temperature TA indicated by the acquired charge acceptance temperature information 122 with the battery temperature TB, and determines whether the battery temperature TB is higher than the charge acceptance temperature TA. If the control unit 11 determines that the battery temperature TB is higher than the charge acceptance temperature TA (Yes in step S130), the control unit 11 proceeds to step S140. If the control unit 11 determines that the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130), the control unit 11 proceeds to step S150.

[0077] (Step S140) In step S140, the control unit 11 operates as the signal generating unit 140, and in the second coolant circuit 60, introduces the second coolant SW only into the battery 30. That is, when the battery temperature TB is higher than the charge acceptance temperature TA, the control unit 11 generates a control signal CS(B) for introducing the second coolant SW only into the battery 30, and outputs the generated control signal CS(B) to the control valve 62.

[0078] When the battery temperature TB is higher than the charge acceptance temperature TA, the control unit 11 introduces the second coolant SW only into the battery 30, thereby enabling the battery 30 to be cooled more quickly than when the second coolant SW is introduced into both the powertrain 20 and the battery 30. Therefore, the control unit 11 can prevent the charge acceptance of the battery 30 from deteriorating.

[0079] (Step S150) In step S150, the control unit 11 operates as the determination unit 130 (particularly the second determination unit 134) and determines whether the battery temperature TB acquired in step S120 is higher than the battery inlet water temperature TIB acquired in step S120. If the control unit 11 determines that the battery temperature TB is higher than the battery inlet water temperature TIB (Yes in step S150), the control unit 11 proceeds to step S160. If the control unit 11 determines that the battery temperature TB is equal to or lower than the battery inlet water temperature TIB (No in step S150), the control unit 11 proceeds to step S190.

[0080] (Step S160) In step S160, the control unit 11 operates as the determination unit 130 (particularly, the third determination unit 136) and determines whether the powertrain outlet water temperature TOP obtained in step S120 is higher than the battery outlet water temperature TOB obtained in step S120. If it is determined that the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB (Yes in step S160), the control unit 11 proceeds to step S170.

[0081] When it is determined that the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB (No in step S160), the control unit 11 proceeds to step S140. As described above, in step S140, the control unit 11 introduces the second coolant SW only to the battery 30, specifically, generates a control signal CS(B) and outputs the generated control signal CS(B) to the control valve 62. That is, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130), the battery temperature TB is higher than the battery inlet water temperature TIB (Yes in step S150), and the powertrain outlet water temperature TOP is equal to or lower than the battery outlet water temperature TOB (No in step S160), the control unit 11 introduces the second coolant SW only to the battery 30.

[0082] Through the above-described control, the control unit 11 achieves the following effects. That is, even when it is considered difficult to recover heat used for heating the passenger compartment of the vehicle 1 from the powertrain 20, the control unit 11 can introduce the second coolant SW into the battery 30 and recover the heat used for heating from the battery 30. Furthermore, by introducing the second coolant SW only into the battery 30, the control unit 11 can cool the battery 30 more quickly than when the second coolant SW is introduced into both the powertrain 20 and the battery 30, and can prevent a deterioration in the charge acceptance of the battery 30.

[0083] (Step S170) In step S170, control unit 11 operates as determination unit 130 (particularly, fourth determination unit 138) and determines whether powertrain outlet water temperature TOP obtained in step S120 is equal to or lower than battery temperature TB obtained in step S120. If control unit 11 determines that powertrain outlet water temperature TOP is equal to or lower than battery temperature TB (Yes in step S170), control unit 11 proceeds to step S180.

[0084] If it is determined that the powertrain outlet water temperature TOP is higher than the battery temperature TB (No in step S170), the control unit 11 proceeds to step S140. In step S140, the control unit 11 introduces the second coolant SW only into the battery 30, and more specifically, generates a control signal CS(B) and outputs the generated control signal CS(B) to the control valve 62.

[0085] By this control, the control unit 11 can cool the battery 30 effectively and quickly with the second coolant SW compared to the case where "the second coolant SW is introduced into both the high-temperature powertrain 20 and the low-temperature battery 30." For example, the control unit 11 can quickly cool the battery 30 with the second coolant SW by avoiding a situation where "the second coolant SW is heated by heat exchange with the high-temperature powertrain 20, and the second coolant SW is unable to cool the battery 30."

[0086] (Step S180) In step S180, the control unit 11 operates as the signal generating unit 140, and introduces the second coolant SW into both the powertrain 20 and the battery 30 in the second coolant circuit 60. That is, the control unit 11 generates a control signal CS (P&B) for introducing the second coolant SW into both the powertrain 20 and the battery 30, and outputs the generated control signal CS (P&B) to the control valve 62.

[0087] As described above, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130), the battery temperature TB is higher than the battery inlet water temperature TIB (Yes in step S150), and the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB (Yes in step S160), the control unit 11 introduces the second cooling water SW into both the powertrain 20 and the battery 30.

[0088] When the battery temperature TB is higher than the battery inlet water temperature TIB, the control unit 11 introduces the second coolant SW into the battery 30, thereby enabling the battery 30 to be cooled by the second coolant SW. Furthermore, when the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the control unit 11 introduces the second coolant SW into the powertrain 20, thereby enabling the second coolant SW to recover heat from the powertrain 20. In particular, by introducing the second coolant SW into the powertrain 20, the control unit 11 can quickly recover heat from the powertrain 20, which has a low thermal resistance, by using the second coolant SW. Therefore, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the battery temperature TB is higher than the battery inlet water temperature TIB, and the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the control unit 11 realizes the following effects by introducing the second coolant SW into both the powertrain 20 and the battery 30. That is, the control unit 11 recovers heat used to heat the passenger compartment of the vehicle 1 from both the powertrain 20 and the battery 30 using the second coolant SW, thereby efficiently heating the passenger compartment and saving the power required for heating. In particular, the control unit 11 quickly recovers heat used to heat the passenger compartment of the vehicle 1 from the powertrain 20 using the second coolant SW, thereby quickly heating the passenger compartment of the vehicle 1. Furthermore, by cooling the battery 30 with the second coolant SW, the control unit 11 can prevent a deterioration in the charge acceptance of the battery 30. By controlling the flow of the second coolant SW in the second coolant circuit 60, the control unit 11 can achieve both efficient heating of the passenger compartment of the vehicle 1 and improved charge acceptance of the battery 30 by cooling the battery 30, thereby improving the power consumption of the vehicle 1.

[0089] In particular, in the example shown in FIG. 6 , when the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130), the battery temperature TB is higher than the battery inlet water temperature TIB (Yes in step S150), the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB (Yes in step S160), and the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB (Yes in step S170), the control unit 11 introduces the second coolant SW into both the powertrain 20 and the battery 30.

[0090] When the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB, the second coolant SW can cool the battery 30 even if it is introduced into both the powertrain 20 and the battery 30. Therefore, when the powertrain outlet water temperature TOP is equal to or lower than the battery temperature TB, the control unit 11 can introduce the second coolant SW into both the powertrain 20 and the battery 30, thereby cooling both batteries 30 with the second coolant SW.

[0091] (Step S190) In step S190, the control unit 11 operates as the signal generating unit 140 and introduces the second coolant SW only into the powertrain 20 in the second coolant circuit 60. That is, the control unit 11 generates a control signal CS(P) for introducing the second coolant SW only into the powertrain 20, and outputs the generated control signal CS(P) to the control valve 62. That is, when the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130) and when the battery temperature TB is equal to or lower than the battery inlet water temperature TIB (No in step S150), the control unit 11 introduces the second coolant SW only into the powertrain 20.

[0092] By this control, even when the second coolant SW cannot cool the battery 30, the control unit 11 can use the second coolant SW to recover heat from the powertrain 20 to be used for heating the passenger compartment of the vehicle 1. In particular, by introducing the second coolant SW into the powertrain 20, which has a small thermal resistance, the control unit 11 can use the second coolant SW to quickly recover heat from the powertrain 20, thereby quickly heating the passenger compartment of the vehicle 1.

[0093] [Features] As described above, the circuit control device 10 according to this embodiment is a circuit control device that recovers heat to be used for heating the passenger compartment of the vehicle 1 from at least one of the powertrain 20 and the battery 30 of the vehicle 1, and includes an acquisition unit 110, a determination unit 130, and a signal generation unit 140.

[0094] The acquisition unit 110 acquires various temperatures, including the powertrain outlet water temperature TOP, the battery inlet water temperature TIB, the battery outlet water temperature TOB, and the battery temperature TB. That is, the acquisition unit 110 acquires the powertrain outlet water temperature TOP, the battery inlet water temperature TIB, the battery outlet water temperature TOB, and the battery temperature TB.

[0095] The powertrain outlet water temperature TOP is the temperature of the first coolant FW in the first coolant circuit 40 through which the first coolant FW that cools the powertrain 20 circulates, and is the temperature of the first coolant FW at the coolant outlet of the powertrain 20. The battery inlet water temperature TIB is the temperature of the second coolant SW in the second coolant circuit 60, and is the temperature of the second coolant SW at the coolant inlet of the battery 30, in other words, the temperature of the second coolant SW at the coolant inlet of the battery 30. The battery outlet water temperature TOB is the temperature of the second coolant SW in the second coolant circuit 60, and is the temperature of the second coolant SW at the coolant outlet of the battery 30, and is in other words, the temperature of the second coolant SW at the coolant outlet of the battery 30. The second coolant SW circulates through the second coolant circuit 60, and is introduced into at least one of the powertrain 20 and the battery 30 to recover heat from at least one of the powertrain 20 and the battery 30. The battery temperature TB is the temperature of the battery 30 .

[0096] The determination unit 130 performs a determination process using the various temperatures acquired by the acquisition unit 110 (i.e., the powertrain outlet water temperature TOP, the battery inlet water temperature TIB, the battery outlet water temperature TOB, and the battery temperature TB). The determination unit 130 includes a first determination unit 132, a second determination unit 134, and a third determination unit 136. The first determination unit 132 compares the battery temperature TB with a charge acceptance temperature TA (a predetermined charge acceptance temperature). The second determination unit 134 compares the battery temperature TB with the battery inlet water temperature TIB. The third determination unit 136 compares the powertrain outlet water temperature TOP with the battery outlet water temperature TOB.

[0097] The signal generating unit 140 generates a control signal CS that controls the flow of the second coolant SW in the second coolant circuit 60, depending on the result of the determination process by the determining unit 130. When the battery temperature TB is equal to or lower than the charge acceptance temperature TA, the battery temperature TB is higher than the battery inlet water temperature TIB, and the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB, the signal generating unit 140 generates a control signal CS (P&B) that introduces the second coolant SW into both the battery 30 and the powertrain 20.

[0098] The circuit control method PM according to the present embodiment is a circuit control method that causes a processor (e.g., the CPU of the circuit control device 10) to execute a process of recovering heat to be used for heating the passenger compartment of the vehicle 1 from at least one of the powertrain 20 and the battery of the vehicle 1. The circuit control method PM causes the processor to execute, for example, steps S120, S130, S150, S160, and S180 of FIG.

[0099] In step S120, the processor acquires the powertrain outlet water temperature TOP, the battery inlet water temperature TIB, the battery outlet water temperature TOB, and the battery temperature TB. In step S130, the processor compares the battery temperature TB with the charge acceptance temperature TA. In step S150, the processor compares the battery temperature TB with the battery inlet water temperature TIB. In step S160, the processor compares the powertrain outlet water temperature TOP with the battery outlet water temperature TOB. In step S180, the processor controls the flow of the second coolant SW in the second coolant circuit 60. In step S180, if the battery temperature TB is equal to or lower than the charge acceptance temperature TA (No in step S130), the battery temperature TB is higher than the battery inlet water temperature TIB (Yes in step S150), and the powertrain outlet water temperature TOP is higher than the battery outlet water temperature TOB (Yes in step S160), the processor introduces the second coolant SW into both the powertrain 20 and the battery 30. In other words, in step S180, the processor generates a control signal CS(P&B) to introduce the second coolant SW into both the battery 30 and the powertrain 20.

[0100] According to this configuration, the circuit control device 10 (circuit control method PM) can recover heat from the battery 30 using the second coolant SW, i.e., can cool the battery 30 using the second coolant SW. Furthermore, the circuit control device 10 (circuit control method PM) can recover heat used to heat the passenger compartment of the vehicle 1 from both the powertrain 20 and the battery 30 using the second coolant SW, thereby saving on the power required for heating. In particular, the circuit control device 10 (circuit control method PM) introduces the second coolant SW into the powertrain 20, which has a low thermal resistance, thereby enabling the second coolant SW to quickly recover heat from the powertrain 20 and quickly heat the passenger compartment of the vehicle 1. By controlling the flow of the second coolant SW in the second coolant circuit 60, the circuit control device 10 (circuit control method PM) can achieve both efficient heating of the passenger compartment of the vehicle 1 and cooling of the battery 30, thereby improving the electric power consumption of the vehicle 1.

[0101] The inventor(s) conducted an experiment in which the vehicle 1 was repeatedly driven and the battery 30 was charged while the passenger compartment of the vehicle 1 was heated. As a result, it was confirmed that the electric fuel economy of the vehicle 1 can be improved by the above-described control using the circuit control device 10 (circuit control method PM).

[0102] §4 Modifications Although the embodiments of the present invention have been described above in detail, the above description is merely an example of the present invention in every respect. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. For example, the following modifications are possible. Note that, in the following, the same reference numerals are used for components similar to those in the above embodiment, and descriptions of similar points to those in the above embodiment are omitted where appropriate. The following modifications can be combined as appropriate.

[0103] In the above embodiment, an example has been described in which the vehicle 1 is a BEV (Battery Electric Vehicle) and is equipped with only a drive motor as a power source (drive source). However, the vehicle 1 may also be equipped with another power source, such as an engine (internal combustion engine), in addition to the drive motor. The vehicle 1 may be, for example, a so-called hybrid vehicle or a plug-in hybrid vehicle. Furthermore, in the above embodiment, an example has been described in which the drive motor also functions as a generator. However, the vehicle 1 may also be equipped with a power generation device, such as a generator rotated by the engine or a fuel cell. The battery 30 may be charged by such a power generation device.

[0104] In the above embodiment, an example has been described in which heat exchange between the battery 30 and the heating system 90 cools the battery 30 and heats the passenger compartment of the vehicle 1 using the heating system 90. That is, in the embodiments described so far, the battery 30 is cooled by the heating system 90 dissipating heat from the battery 30 into the passenger compartment of the vehicle 1. However, it is not essential for the circuit control device 10 (circuit control method PM) to dissipate heat from the battery 30 using only the heating system 90, that is, it is not essential to cool the battery 30 using only the heating system 90. For example, as illustrated in FIG. 7 , the circuit control device 10 (circuit control method PM) may cool the battery 30 using the heating system 190 and a radiator 50, that is, the heat from the battery 30 may be dissipated to the passenger compartment of the vehicle 1 and outside the vehicle.

[0105] 7 , a heating system 190 that heats the passenger compartment of the vehicle 1A by utilizing heat recovered from at least one of the powertrain 20 and the battery 30 includes a water condenser 194 and a heater 196. Similar to the condenser 94 illustrated in FIG. 2 , the water condenser 194 realizes heat exchange between the refrigerant RF circulating through the refrigerant circuit 80 and the heater 196. In the illustrated example, in the water condenser 194, heat is transferred from the refrigerant RF to the fourth coolant CW circulating through the fourth coolant circuit 230, and the heater 196 heats air (outside air) using the fourth coolant CW and blows the heated air into the passenger compartment of the vehicle 1 as hot air.

[0106] The water condenser 194 also realizes heat exchange between the refrigerant RF circulating through the refrigerant circuit 80 and the third coolant TW circulating through a third coolant circuit 210 including the radiator 50. The heat transferred from the refrigerant RF to the third coolant TW in the water condenser 194 is then dissipated by the radiator 50 to the outside of the vehicle 1A.

[0107] That is, in vehicle 1A, the heat of the refrigerant RF circulating through refrigerant circuit 80 is not only used by heating system 190 to heat the passenger compartment of vehicle 1A, but is also radiated to the outside of vehicle 1A by radiator 50. As described above, refrigerant RF recovers heat from second coolant SW in chiller 70. Furthermore, second coolant SW is introduced into at least one of powertrain 20 and battery 30, thereby recovering heat from at least one of powertrain 20 and battery 30. Therefore, in vehicle 1A, heat from at least one of powertrain 20 and battery 30 is used by heating system 190 to heat the passenger compartment of vehicle 1A, and is also radiated to the outside of vehicle 1A by radiator 50. In other words, in vehicle 1A, at least one of powertrain 20 and battery 30 is cooled by heating system 90 and radiator 50. The circuit control device 10 (circuit control method PM) introduces the second coolant SW into the battery 30 and recovers heat from the battery 30 using the second coolant SW. The recovered heat from the battery 30 is not only used to heat the passenger compartment of the vehicle 1A by the heating system 190, but is also radiated to the outside of the vehicle 1A by the radiator 50. Therefore, in the vehicle 1A, the circuit control device 10 (circuit control method PM) can cool the battery 30 more quickly using the heating system 190 and the radiator 50 compared to a case in which the battery 30 is cooled only by the heating system 90. Furthermore, the circuit control device 10 (circuit control method PM) can cool the battery 30 using the radiator 50 even when there is no need to heat the passenger compartment of the vehicle 1A using the heating system 190.

[0108] 1, 1A... Vehicle (electric vehicle), 10... Circuit control device, 20... Powertrain, 30... Battery, 40... First coolant circuit, 60... Second coolant circuit, 110... Acquisition unit, 130... Determination unit, 140... Signal generation unit, CS... Control signal, FW... First coolant, PM... Circuit control method, SW... Second coolant, TA... Charge acceptance temperature, TB... Battery temperature, TIB... Battery inlet water temperature, TOB... Battery outlet water temperature, TOP... Powertrain outlet water temperature

Claims

1. A circuit control method for causing a processor to execute a process of recovering heat to be used for heating the passenger compartment of an electric vehicle from at least one of a powertrain and a battery of the electric vehicle, the processor performing the following steps: acquiring a powertrain outlet water temperature, which is the temperature of first coolant in a first coolant circuit through which first coolant for cooling the powertrain circulates, and which is the temperature of the first coolant at a coolant outlet of the powertrain; acquiring temperatures of second coolant in a second coolant circuit through which second coolant circulates, which is introduced into at least one of the powertrain and the battery to recover the heat of at least one of the powertrain and the battery, and which is the battery inlet water temperature, which is the temperature of the second coolant at a coolant inlet of the battery; acquiring a battery temperature, which is the temperature of the battery; comparing the battery temperature with a predetermined charge acceptance temperature; and comparing the battery temperature with the battery inlet water temperature. a step of comparing the powertrain outlet water temperature with the battery outlet water temperature; and a step of controlling a flow of the second coolant in the second coolant circuit, wherein, when the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, and the powertrain outlet water temperature is higher than the battery outlet water temperature, the second coolant is introduced into both the battery and the powertrain.

2. The circuit control method according to claim 1, wherein in the controlling step, the processor introduces the second coolant only into the battery when the battery temperature is higher than the charge acceptance temperature.

3. A circuit control method according to claim 1 or 2, wherein in the controlling step, the processor introduces the second cooling water only into the power train when the battery temperature is equal to or lower than the charge acceptance temperature and the battery temperature is equal to or lower than the battery inlet water temperature.

4. A circuit control method according to claim 1 or 2, wherein in the controlling step, the processor introduces the second cooling water only into the battery when the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, and the powertrain outlet water temperature is equal to or lower than the battery outlet water temperature.

5. A circuit control method according to claim 1 or 2, wherein the processor further executes a step of comparing the powertrain outlet water temperature with the battery temperature, and in the controlling step, the processor introduces the second cooling water into both the battery and the powertrain when the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, the powertrain outlet water temperature is higher than the battery outlet water temperature, and the powertrain outlet water temperature is equal to or lower than the battery temperature.

6. The circuit control method according to claim 5, wherein in the controlling step, the processor introduces the second coolant only into the battery when the powertrain outlet water temperature is higher than the battery temperature.

7. A circuit control device that recovers heat used to heat the passenger compartment of an electric vehicle from at least one of a powertrain and a battery of the electric vehicle, comprising: an acquisition unit that acquires various temperatures, the various temperatures including: a powertrain outlet water temperature, which is the temperature of a first coolant in a first coolant circuit through which a first coolant that cools the powertrain circulates, the powertrain outlet water temperature being the temperature of the first coolant at a coolant outlet of the powertrain; a second coolant circuit, through which a second coolant that is introduced into at least one of the powertrain and the battery thereby recovering the heat of at least one of the powertrain and the battery circulates, the second coolant temperature being the temperature of the second coolant at a coolant inlet of the battery; a battery outlet water temperature, which is the temperature of the second coolant at a coolant outlet of the battery; and a battery temperature, which is the temperature of the battery; and a determination unit that performs a determination process using the various temperatures acquired by the acquisition unit, the first determination unit that compares the battery temperature with a predetermined charge acceptance temperature. a determination unit including: a second determination unit that compares the battery temperature with the battery inlet water temperature; and a third determination unit that compares the powertrain outlet water temperature with the battery outlet water temperature; and a signal generation unit that generates a control signal to control a flow of the second coolant in the second coolant circuit according to a result of the determination process by the determination unit, wherein the signal generation unit generates the control signal to introduce the second coolant into both the battery and the powertrain when the battery temperature is equal to or lower than the charge acceptance temperature, the battery temperature is higher than the battery inlet water temperature, and the powertrain outlet water temperature is higher than the battery outlet water temperature.

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