Thermal management system and control method for a thermal management system

Abstract

To provide a thermal management system capable of transmitting heat obtained by heat exchange before a refrigerant circulates in a battery to the battery efficiently.SOLUTION: A thermal management system 1 includes: a thermal management circuit 100 having a low-temperature circuit 130 (a first refrigerant circuit) and a high-temperature circuit 110 (a second refrigerant circuit); a five-way valve 180 (a first switching valve); a heat exchanger 176; and an ECU 500 (a control device). The heat exchanger 176 is connected to a portion 170a located between a battery 172 and the five-way valve 180 of the low-temperature circuit 130, and a portion 110a (a predetermined portion) of the high-temperature circuit 110. The ECU 500 is configured to control the five-way valve 180 such that a heat medium circulates through the battery 172, and to control an electric heater 112, so as to control heat exchange in the heat exchanger 176.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a thermal management system and a method for controlling the thermal management system.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2021-156234 discloses a thermal management device in which a battery, a first radiator, and a second radiator are provided in a thermal circuit. In the thermal circuit, heat exchange is performed between a first heat medium flowing through the first radiator and a second heat medium flowing through the second radiator. Further, a three-way valve for controlling the flow of the first heat medium to the battery is provided in the thermal circuit.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in the thermal circuit as described in Patent Document 1 above, it is possible to adjust the temperature of the battery by using the heat obtained by the first heat medium through heat exchange between the first radiator and the second radiator. However, for example, when the position where heat exchange is performed is far from the battery, it is conceivable that much of the heat obtained by the first heat medium is lost (escapes) on the way. In this case, it becomes difficult to transfer the heat obtained by the first heat medium through heat exchange to the battery. Therefore, it is desired that the heat obtained by the heat medium (refrigerant) through heat exchange be efficiently transferred to the battery.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a thermal management system and a method for controlling the thermal management system that can efficiently transfer the heat obtained by the refrigerant through heat exchange to the battery before the refrigerant flows through the battery. [Means for solving the problem]

[0006] The thermal management system according to the first aspect of this disclosure comprises a thermal management circuit having a first refrigerant circuit through which a first refrigerant flows and which includes a battery and a first radiator, and a second refrigerant circuit through which a second refrigerant different from the first refrigerant flows and which includes a heater; a first switching valve for switching whether the first refrigerant flows through the battery or not; a heat exchanger connected to the portion of the first refrigerant circuit between the battery and the first switching valve, and to a predetermined portion of the second refrigerant circuit, and which performs heat exchange between the first refrigerant and the second refrigerant; and a control device for controlling the first switching valve and the heater, respectively. The control device controls the heat exchange between the first refrigerant and the second refrigerant in the heat exchanger by controlling the first switching valve so that the first refrigerant flows through the battery and by controlling the heater.

[0007] In the thermal management system relating to the first aspect of this disclosure, as described above, the portion of the first refrigerant circuit between the battery and the first switching valve is connected to the heat exchanger. This allows the distance between the heat exchanger and the battery to be shortened compared to the case where the portion of the first refrigerant circuit opposite the battery to the first switching valve is connected to the heat exchanger in the flow direction of the first refrigerant. As a result, the amount of heat lost (escaping) from the first refrigerant before it reaches the battery can be reduced. This allows the first refrigerant to efficiently transfer the heat it has gained through heat exchange to the battery before it reaches the battery.

[0008] In the thermal management system relating to the first aspect described above, preferably, the second refrigerant circuit further includes a second radiator different from the first radiator. The heat exchanger is provided separately from each of the first and second radiators. With this configuration, the battery temperature can be adjusted using the heat exchanger in addition to the first and second radiators, making it easy to adjust the battery temperature.

[0009] The heat management system relating to the first aspect described above preferably further includes a second switching valve for switching whether or not the second refrigerant flows through the heat exchanger. When heat exchange between the first refrigerant and the second refrigerant is performed in the heat exchanger, the control device controls the second switching valve so that the second refrigerant flows through the heat exchanger. With this configuration, heat exchange in the heat exchanger can be easily controlled by controlling the second switching valve.

[0010] The thermal management system relating to the first aspect described above preferably further includes a temperature detection unit for detecting the temperature of the battery. The control device controls the heat exchange between the first refrigerant and the second refrigerant in the heat exchanger based on the battery temperature detected by the temperature detection unit. With this configuration, the battery temperature can be controlled with high precision according to the detection result of the temperature detection unit.

[0011] In this case, preferably, the control device performs temperature-raising control to raise the temperature of the battery by driving the heater to raise the temperature of the second refrigerant when the battery temperature detected by the temperature sensing unit is lower than a threshold, thereby raising the temperature of the first refrigerant which exchanges heat with the second refrigerant. With this configuration, temperature-raising control can be easily started based on the threshold.

[0012] In a thermal management system that performs temperature-raising control when the battery temperature is below a threshold, preferably, the control device performs temperature-raising control when the battery temperature detected by the temperature detection unit is below the threshold and external charging of the battery is performed. With this configuration, the battery can be easily heated based on its temperature when external charging is performed. In addition, since the battery temperature can be raised during external charging, the efficiency of external charging can be increased and the charging time can be shortened.

[0013] In the thermal management system that performs temperature-raising control when the battery temperature is below a threshold, the battery is preferably mounted on an electric vehicle. When the temperature of the battery detected by the temperature sensing unit is below a threshold, the control device maintains the battery temperature at a predetermined temperature by performing temperature-raising control between the time the battery is charged and the start of operation of the electric vehicle. With this configuration, the electric vehicle can start running with the battery warmed up.

[0014] In a thermal management system equipped with the above-described temperature detection unit, preferably, the control device performs cooling control to cool the battery by stopping the operation of the heater and cooling the second refrigerant when the temperature of the battery detected by the temperature detection unit is higher than a threshold, thereby cooling the first refrigerant that exchanges heat with the second refrigerant. With this configuration, cooling control can be easily started based on the threshold.

[0015] A control method for a thermal management system relating to a second aspect of the present disclosure is a control method for a thermal management system including a thermal management circuit having a first refrigerant circuit through which a first refrigerant flows and which includes a battery and a radiator, and a second refrigerant circuit through which a second refrigerant different from the first refrigerant flows and which includes a heater. The thermal management system further includes a first switching valve for switching whether the first refrigerant flows through the battery, and a heat exchanger connected to the portion of the first refrigerant circuit between the battery and the first switching valve, and to a predetermined portion of the second refrigerant circuit, and which performs heat exchange between the first refrigerant and the second refrigerant. The control method comprises the steps of controlling the first switching valve so that the first refrigerant flows through the battery, controlling the heater, and performing heat exchange between the second refrigerant, whose temperature has been adjusted by the heater control, and the first refrigerant in the heat exchanger.

[0016] In the control method of the thermal management system according to the second aspect of the present disclosure, as described above, heat exchange between the first refrigerant and the second refrigerant is performed using the heat exchanger connected to the portion between the battery and the first switching valve in the first refrigerant circuit. As a result, it is possible to provide a control method of a thermal management system capable of efficiently transferring the heat obtained by the first refrigerant through heat exchange to the battery before the first refrigerant flows through the battery.

Effects of the Invention

[0017] According to the present disclosure, the heat obtained by the refrigerant through heat exchange can be efficiently transferred to the battery before the refrigerant flows through the battery.

Brief Description of the Drawings

[0018] [Figure 1] It is a diagram showing the configuration of a thermal management system according to an embodiment. [Figure 2] It is a diagram showing the detailed configuration of a thermal management system according to an embodiment. [Figure 3] It is a diagram showing an example of the state of a thermal management circuit according to an embodiment. [Figure 4] It is a diagram showing an example of the state of a thermal management circuit when adjusting the battery temperature according to an embodiment. [Figure 5] It is a flowchart showing preheating control before rapid charging of a thermal management system according to an embodiment. [Figure 6] It is a flowchart showing temperature increase control during rapid charging of a thermal management system according to an embodiment. [Figure 7] It is a flowchart showing temperature increase control during normal charging of a thermal management system according to an embodiment. [Figure 8] It is a flowchart showing heat retention control after normal charging of a thermal management system according to an embodiment. [Figure 9] It is a flowchart showing cooling control of a thermal management system according to an embodiment. [Figure 10] It is a diagram showing the configuration of an electric vehicle equipped with a thermal management system according to an embodiment.

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0020] Hereinafter, a configuration in which the heat management system 1 according to the present disclosure is mounted on an electric vehicle 10 (see FIG. 10) will be described as an example. The electric vehicle 10 is a vehicle equipped with a traveling battery, and for example, it is a battery electric vehicle (BEV). The electric vehicle 10 may be a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a fuel cell electric vehicle (FCEV). However, the application of the heat management system according to the present disclosure is not limited to vehicle use.

[0021] <Overall Configuration> FIG. 1 is a diagram showing an example of the overall configuration of a heat management system 1 according to an embodiment of the present disclosure. The heat management system 1 includes a heat management circuit 100, an electronic control unit (ECU) 500, and a human machine interface (HMI) 600. The ECU 500 is an example of the "control device" of the present disclosure.

[0022] The heat management circuit 100 is configured such that a heat medium circulates. The heat management circuit 100 includes, for example, a high-temperature circuit 110, a radiator 120, a low-temperature circuit 130, a capacitor 140, a refrigeration cycle 150, a chiller 160, a battery circuit 170, and a five-way valve 180. The refrigerant circuit including the low-temperature circuit 130 and the battery circuit 170 is an example of the "first refrigerant circuit" of the present disclosure. The high-temperature circuit 110 is an example of the "second refrigerant circuit" of the present disclosure. The five-way valve 180 is an example of the "first switching unit" of the present disclosure.

[0023] The high-temperature circuit 110 includes, for example, a water pump (W / P) 111, an electric heater 112, a four-way valve 113, a heater core 114, a reservoir tank (R / T) 115, and a high-temperature (HT) radiator 121, which will be described later. The electric heater 112 and the high-temperature radiator 121 are examples of the "heater" and "second radiator" as defined herein, respectively.

[0024] Radiator 120 is connected to (i.e., shared by) both the high-temperature circuit 110 and the low-temperature circuit 130. Radiator 120 includes a high-temperature radiator 121 and a low-temperature (LT) radiator 122 (see Figure 2 for both). Note that the low-temperature radiator 122 is an example of the "first radiator" in this disclosure.

[0025] The low-temperature circuit 130 includes, for example, a water pump 131, a smart power unit (SPU) 132, a power control unit (PCU) 133, an oil cooler (O / C) 134, a buck-boost converter 135, and a low-temperature radiator 122.

[0026] The capacitor 140 is connected to both the high-temperature circuit 110 and the refrigeration cycle 150.

[0027] The refrigeration cycle 150 includes, for example, a compressor 151, an expansion valve 152, an evaporator 153, an evaporation pressure regulator (EPR) 154, and an expansion valve 155.

[0028] The chiller 160 is connected to both the refrigeration cycle 150 and the battery circuit 170.

[0029] The battery circuit 170 includes, for example, a water pump 171, a battery 172, a bypass path 173, a reservoir tank 174, a temperature sensor 175, and a heat exchanger 176. The heat exchanger 176 is also connected to the high-temperature circuit 110. The temperature sensor 175 is an example of the "temperature sensing unit" described herein.

[0030] The five-way valve 180 is connected to the low-temperature circuit 130 and the battery circuit 170. The configuration of the thermal management circuit 100 is explained in detail in Figure 2.

[0031] The ECU 500 controls the thermal management circuit 100. The ECU 500 includes a processor 501, memory 502, storage 503, and interface 504.

[0032] The processor 501 is, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The memory 502 is, for example, RAM (Random Access Memory). The storage 503 is a rewritable non-volatile memory such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory. The storage 503 stores a system program including the OS (Operating System) and a control program including computer-readable code necessary for control calculations. The processor 501 performs various processes by reading the system program and the control program, loading them into the memory 502, and executing them. The interface 504 controls communication between the ECU 500 and the components of the thermal management circuit 100.

[0033] The ECU 500 generates control commands based on sensor values ​​obtained from various sensors (for example, the temperature sensor 175) included in the thermal management circuit 100, user operations received by the HMI 600, and outputs the generated control commands to the thermal management circuit 100. For example, the ECU 500 switches the path through which the heat transfer medium flows by controlling the state of the five-way valve 180 and the four-way valve 113. The ECU 500 also controls the on / off state and output (temperature) of the electric heater 112. The ECU 500 may be divided into multiple ECUs for each function. Also, although Figure 1 shows an example in which the ECU 500 includes one processor 501, the ECU 500 may include multiple processors. The same applies to the memory 502 and storage 503.

[0034] In this specification, "processor" is not limited to processors that execute processing using stored-program methods, but may also include hardwired circuits such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field-Programmable Gate Arrays). Therefore, the term "processor" can also be interpreted as processing circuitry in which processing is predefined by computer-readable code and / or hardwired circuits.

[0035] The HMI600 consists of a touchscreen display, control panel, console, etc. The HMI600 receives user input to control the thermal management system 1. The HMI600 outputs signals indicating user input to the ECU500.

[0036] <Configuration of the thermal management circuit> Figure 2 shows an example of the configuration of the thermal management circuit 100 in this embodiment. The heat transfer medium (usually hot water) circulating in the high-temperature circuit 110 flows through at least one of the following paths: a first path from water pump 111 - condenser 140 - electric heater 112 - four-way valve 113 - heater core 114 - reservoir tank 115 - water pump 111; a second path from water pump 111 - condenser 140 - electric heater 112 - four-way valve 113 - high-temperature radiator 121 - reservoir tank 115 - water pump 111; and a third path from water pump 111 - condenser 140 - electric heater 112 - four-way valve 113 - heat exchanger 176 - water pump 111. The heat transfer medium circulating in the high-temperature circuit 110 is an example of the "second refrigerant" in this disclosure.

[0037] The four-way valve 113 is configured to switch whether the heat transfer medium flowing through the high-temperature circuit 110 flows through the heat exchanger 176. The four-way valve 113 is also provided with four ports P11 to P14. Port P11 is an outlet port through which the heat transfer medium flows out toward the heater core. Port P12 is an outlet port through which the heat transfer medium flows out toward the high-temperature radiator 121. Port P13 is an inlet port through which the heat transfer medium flows in from the electric heater 112. Port P14 is an outlet port through which the heat transfer medium flows out toward the heat exchanger 176.

[0038] The heat transfer medium (coolant) circulating in the low-temperature circuit 130 flows through the following path: water pump 131 - SPU 132 - PCU 133 - oil cooler 134 - step-up / step-down converter 135 - five-way valve 180 - low-temperature radiator 122 - water pump 131. The heat transfer medium circulating in the low-temperature circuit 130 is an example of the "first refrigerant" in this disclosure.

[0039] The water pump 131 circulates the heat transfer medium in the low-temperature circuit 130 according to control commands from the ECU 500. The SPU 132 controls the charging and discharging of the battery 172 according to control commands from the ECU 500. The PCU 133 converts the DC power supplied from the battery 172 into AC power according to control commands from the ECU 500 and supplies that AC power to a motor (not shown) built into the transaxle. The oil cooler 134 circulates the motor's lubricating oil using an electric oil pump (EOP) (not shown). The SPU 132, PCU 133, oil cooler 134, and buck-boost converter 135 are cooled by the heat transfer medium circulating in the low-temperature circuit 130. The five-way valve 180 switches the paths of the heat transfer medium in the low-temperature circuit 130 and the battery circuit 170 according to control commands from the ECU 500. The low-temperature radiator 122 is positioned near the high-temperature radiator 121 and exchanges heat with the high-temperature radiator 121.

[0040] The heat transfer medium (gas-phase or liquid-phase refrigerant) circulating in the refrigeration cycle 150 flows through one or both of the following paths: the first path from compressor 151 to condenser 140 to expansion valve 152 to evaporator 153 to EPR 154 to compressor 151, and the second path from compressor 151 to condenser 140 to expansion valve 155 to chiller 160 to compressor 151.

[0041] The heat transfer medium (coolant) circulating in the battery circuit 170 flows through one or both of the following paths: a first path from water pump 171 - chiller 160 - five-way valve 180 - heat exchanger 176 - battery 172 - reservoir tank 174 - water pump 171, and a second path from water pump 171 - chiller 160 - five-way valve 180 - bypass path 173 - reservoir tank 174 - water pump 171. The heat transfer medium circulating in the battery circuit 170 is an example of the "first refrigerant" in this disclosure.

[0042] The water pump 171 circulates the heat transfer medium within the battery circuit 170 according to control commands from the ECU 500. The chiller 160 cools the heat transfer medium circulating in the battery circuit 170 by heat exchange between the heat transfer medium circulating in the refrigeration cycle 150 and the heat transfer medium circulating in the battery circuit 170. The battery 172 supplies power for driving to the motor built into the transaxle. The battery 172 may be heated using the heat exchanger 176 or cooled using the chiller 160. A bypass path 173 is provided so that the heat transfer medium bypasses the heat exchanger 176 and the battery 172. When the heat transfer medium flows through the bypass path 173, temperature changes in the heat transfer medium due to heat absorption / dissipation between the heat transfer medium and the battery 172 can be suppressed. The reservoir tank 174 maintains the pressure and amount of heat transfer medium in the battery circuit 170 by storing a portion of the heat transfer medium in the battery circuit 170. The temperature sensor 175 (see Figure 1) detects the temperature of the battery 172. The results detected by the temperature sensor 175 are transmitted to the ECU 500. The heat exchanger 176 is connected to section 170a between the battery 172 and the five-way valve 180, and is also connected to section 110a of the high-temperature circuit 110.

[0043] The five-way valve 180 is configured to switch whether the heat transfer medium flowing through the low-temperature circuit 130 flows through the battery 172. The five-way valve 180 is also provided with five ports P1 to P5. Port P1 is an inlet port into which the heat transfer medium flows from the chiller 160. Port P2 is an outlet port into which the heat transfer medium flows out toward the heat exchanger 176 and battery 172 of the battery circuit 170. Port P3 is an inlet port into which the heat transfer medium flows from the SPU 132, PCU 133, oil cooler 134, and buck-boost converter 135 of the low-temperature circuit 130. Port P4 is an outlet port into which the heat transfer medium flows out toward the bypass path 173 of the battery circuit 170. Port P5 is an outlet port into which the heat transfer medium flows out toward the low-temperature radiator 122.

[0044] <Communication Pattern> Figures 3 and 4 are conceptual diagrams showing the first and second communication patterns, respectively, by the five-way valve 180. As shown in Figure 3, in the first communication pattern, the five-way valve 180 forms a path connecting port P1 and port P5, and a path connecting port P3 and port P2. In this case, the low-temperature circuit 130 and the battery circuit 170 are connected in series.

[0045] Furthermore, in the first communication pattern (see Figure 3), port P14 of the four-way valve 113 is closed by the ECU 500. As a result, the heat transfer medium flowing through the high-temperature circuit 110 does not flow through the heat exchanger 176.

[0046] The second communication pattern (see Figure 4) differs from the first communication pattern (see Figure 3) in that port P14 of the four-way valve 113 is opened by the ECU 500. As a result, in the second communication pattern, the heat transfer medium that flows from the electric heater 112 to port P13 flows out from port P14 and also circulates to the heat exchanger 176. As mentioned above, the heat exchanger 176 is connected to part 110a of the high-temperature circuit 110 (see Figure 2). As a result, in the second communication pattern, the heat transfer medium circulating in the battery circuit 170 (low-temperature circuit 130) and the heat transfer medium circulating in the high-temperature circuit 110 each flow into the heat exchanger 176. Consequently, heat exchange takes place in the heat exchanger 176 between the heat transfer medium circulating in the battery circuit 170 (low-temperature circuit 130) and the heat transfer medium circulating in the high-temperature circuit 110.

[0047] In conventional thermal management circuits, the battery temperature is sometimes regulated by using the heat gained by the heat transfer medium in the low-temperature circuit through heat exchange between a high-temperature radiator and a low-temperature radiator. However, depending on the location of the radiators, much of the heat gained by the heat transfer medium through heat exchange may be lost (escape) before reaching the battery. In this case, it becomes difficult to transfer the heat gained by the heat transfer medium through heat exchange to the battery. It is desirable to efficiently transfer the heat gained by the heat transfer medium through heat exchange to the battery.

[0048] Therefore, in this embodiment, the heat exchanger 176 is connected to the portion 170a of the battery circuit 170 between the five-way valve 180 and the battery 172. On the other hand, the low-temperature radiator 122 is located on the opposite side of the battery 172 from the five-way valve 180 in the direction of heat transfer fluid flow in the low-temperature circuit 130. Consequently, in the direction of heat transfer fluid flow in the low-temperature circuit 130, the heat exchanger 176 is located closer to the battery 172 than the low-temperature radiator 122. This makes it possible to suppress the decrease in the temperature of the heat transfer fluid as it travels from the heat exchanger 176 to the battery 172.

[0049] <Control method for thermal management system> The control method of the thermal management system 1 (ECU500) will be explained with reference to the flow charts in Figures 5 to 9. Note that the temperature threshold values ​​for the battery 172 in each flow chart are examples only and are not limited to the values ​​listed below. Also, each flow chart is merely an example and is not limited to the examples shown below.

[0050] (Preheating control before rapid charging) Figure 5 is a flowchart of the preheating control of the battery 172 before rapid charging (while driving). In step S1, the ECU 500 detects that a rapid charger has been found in the navigation system (not shown) of the electric vehicle 10. The navigation system may display a message asking whether or not to perform temperature rise control of the battery 172 using an electric heater. In this case, if the user chooses to perform temperature rise control, the control from step S2 onward may be executed. In addition, the navigation system may display a message regarding whether or not there is enough power remaining to reach the rapid charger if temperature rise control is performed.

[0051] In step S2, the ECU 500 determines whether the temperature of the battery 172 detected by the temperature sensor 175 is, for example, below 0°C. Below 0°C is an example of a temperature range that indicates the temperature of the battery 172 is too low to be used for charging. If the temperature of the battery 172 is below 0°C (Yes in S2), the process proceeds to step S3. If the temperature of the battery 172 is 0°C or higher (No in S2), the process ends. Note that the above 0°C is an example of a "threshold" in this disclosure. The threshold may be a value other than 0°C.

[0052] In step S3, the ECU 500 raises the temperature of the heat transfer medium flowing through the high-temperature circuit 110 by controlling the electric heater 112. Controlling the electric heater 112 includes processes such as activating the electric heater 112 and increasing the output (set temperature) of the electric heater 112.

[0053] In step S4, the ECU 500 controls the five-way valve 180 so that the heat transfer medium flowing through the low-temperature circuit 130 flows through the heat exchanger 176 (battery 172). In step S5, the ECU 500 controls the four-way valve 113 so that the heat transfer medium from the electric heater 112 flows through the heat exchanger 176. As a result, the thermal management circuit 100 enters the state of the second flow pattern (see Figure 4). Note that the processing in step S3 and the processing in steps S4 and S5 may be executed in any order, or they may be executed simultaneously. Also, the processing in step S4 and the processing in step S5 may be executed in any order, or they may be executed simultaneously.

[0054] In step S6, the ECU 500 determines whether the temperature of the battery 172 detected by the temperature sensor 175 is, for example, between 0°C and 15°C. If the temperature of the battery 172 is between 0°C and 15°C (Yes in S6), the process proceeds to step S8. If the temperature of the battery 172 is not between 0°C and 15°C (No in S6), the process proceeds to step S7. Note that if the temperature is higher than the temperature before the start of heating by the electric heater 112 and is within a temperature range suitable for charging the battery 172, a range other than 0°C to 15°C may be used as the determination criterion.

[0055] In step S7, the ECU 500 adjusts the output of the electric heater 112. For example, if in step S6 it is determined that the temperature of the battery 172 is below 0°C, the ECU 500 may increase the output of the electric heater 112 or maintain the current output. Also, if in step S6 it is determined that the temperature of the battery 172 is above 15°C, the ECU 500 may reduce the output of the electric heater 112 or turn off the electric heater 112.

[0056] In step S8, the ECU 500 determines whether the electric vehicle 10 has been plugged into the fast charger. If the electric vehicle 10 has been plugged into the fast charger (Yes in S8), the process ends. If the electric vehicle 10 has not been plugged into the fast charger (No in S8), the process returns to step S6.

[0057] (Temperature control during rapid charging) Figure 6 is a flowchart of the temperature rise control of the battery 172 during external charging by rapid charging. In step S11, the ECU 500 detects that external charging by rapid charging has started.

[0058] Furthermore, the processes in steps S12 to S17 are the same as those in steps S2 to S7 in Figure 5. In step S12, the ECU 500 determines whether the temperature of the battery 172 is, for example, less than 10°C. In step S16, the ECU 500 determines whether the temperature of the battery 172 is between 10°C and 35°C. The threshold of 10°C in step S12 is just one example of a "threshold" in this disclosure. The threshold may be a value other than 10°C. Also, in step S16, a range other than 10°C to 35°C may be used as the criterion for determination.

[0059] In step S18, the ECU500 determines whether external charging has finished. If external charging has finished (Yes in S18), the process ends. If external charging has not finished (No in S18), the process returns to step S16.

[0060] (Temperature control during normal charging) Figure 7 is a flowchart of the temperature rise control of battery 172 during external charging using normal charging. In step S21, the ECU 500 detects that external charging using normal charging has started. Normal charging refers to slow charging, which has a lower charging speed than fast charging.

[0061] Furthermore, the processing in steps S22 to S28 is the same as the processing in steps S12 to S18 in Figure 6. In step S22, the ECU 500 determines whether the temperature of the battery 172 is less than 5°C. In step S26, the ECU 500 determines whether the temperature of the battery 172 is between 5°C and 40°C. The threshold of 5°C in step S22 is just one example of a "threshold" in this disclosure. The threshold may be a value other than 5°C. Also, in step S26, a range other than 5°C to 40°C may be used as the determination criterion.

[0062] (Temperature control after normal charging) Figure 8 is a flowchart of the control for keeping the battery 172 warm after normal charging. In step S31, the ECU 500 detects that external charging by normal charging has been completed.

[0063] Furthermore, the processes in steps S32 to S37 are the same as those in steps S12 to S17 in Figure 6. In step S32, the ECU 500 determines whether the temperature of the battery 172 is less than 5°C. In step S36, the ECU 500 determines whether the temperature of the battery 172 is maintained within the range of 18°C ​​to 22°C (a temperature range suitable for charging and discharging the battery 172 when the electric vehicle 10 is running). The threshold of 5°C in step S32 is merely an example of a "threshold" in this disclosure. The threshold may be a value other than 5°C. Also, in step S36, a range other than 18°C ​​to 22°C may be used as the criterion for determination.

[0064] In step S38, the ECU 500 determines whether or not the scheduled departure time set by the user of the electric vehicle 10 has arrived. If the scheduled departure time has arrived (Yes in S38), the process ends. If the scheduled departure time has not arrived (No in S38), the process returns to step S36.

[0065] (Cooling control during driving) Figure 9 is a flowchart of the cooling control of the battery 172 while the electric vehicle 10 is running. In step S41, the ECU 500 detects that the electric vehicle 10 is running. Step S41 may also be a step in which, for example, the electric vehicle 10 starts charging.

[0066] In step S42, the ECU 500 determines whether the temperature of the battery 172 detected by the temperature sensor 175 is higher than, for example, 45°C. If the temperature of the battery 172 is higher than 45°C (Yes in S42), the process proceeds to step S43. If the temperature of the battery 172 is 45°C or lower (No in S42), the process ends because the temperature of the battery 172 is suitable for charging and discharging the battery 172. Note that the above 45°C is an example of a "threshold" in this disclosure. The threshold may be a value other than 45°C.

[0067] In step S43, the ECU 500 determines whether the temperature of the battery 172 detected by the temperature sensor 175 is, for example, higher than 60°C. A temperature above 60°C is an example of a temperature range indicating that the temperature of the battery 172 is too high for charging or discharging (a temperature requiring rapid cooling of the battery 172). If the temperature of the battery 172 is higher than 60°C (Yes in S43), the process proceeds to step S43a. If the temperature of the battery 172 is 60°C or lower (No in S43), the process proceeds to step S44. Note that the threshold value may be other than 60°C.

[0068] In step S43a, the ECU 500 controls the cooling of the battery 172 by driving the chiller 160. The process then proceeds to step S44.

[0069] In step S44, the ECU 500 stops (or reduces the output of) the electric heater 112. This cools the heat transfer medium flowing through the high-temperature circuit 110.

[0070] The processes in steps S45 to S47 are the same as those in steps S4 to S6 in Figure 5, so a repeated explanation will not be given. In step S47, the ECU 500 determines whether the temperature of the battery 172 is within the range of 5°C to 45°C (a suitable temperature range for charging and discharging the battery 172 when the electric vehicle 10 is running). In step S47, a range other than 5°C to 45°C may be used as the determination criterion.

[0071] In step S48, the ECU 500 adjusts the output of the electric heater 112. For example, if in step S47 the temperature of the battery 172 is determined to be less than 5°C, the ECU 500 may activate the electric heater 112 that is currently stopped, or increase the output of the electric heater 112 that is currently running. Alternatively, if in step S47 the temperature of the battery 172 is determined to be higher than 45°C, the ECU 500 may deactivate the electric heater 112 that is currently running, or decrease the output of the electric heater 112 that is currently running.

[0072] In step S49, the ECU 500 determines whether the electric vehicle 10 has finished running. If the running is finished (Yes in S49), the process ends. If the running is not finished (No in S49), the process returns to step S47.

[0073] As described above, in this embodiment, the ECU 500 controls the heat exchange in the heat exchanger 176 to which the portion 170a between the battery 172 and the five-way valve 180 is connected. As a result, the temperature of the battery 172 can be controlled by the heat exchanger 176, which is located relatively close to the battery 172, and thus the temperature of the battery 172 can be controlled with high precision.

[0074] In the above embodiment, an example was shown in which a four-way valve 113 is provided in the thermal management circuit 100, but the disclosure is not limited thereto. The thermal management circuit 100 may be provided with a multi-way valve other than a four-way valve, or it may not be provided with a four-way valve 113 at all.

[0075] In the above embodiment, an example was shown in which heat exchange in the heat exchanger 176 is controlled based on the detected value of a temperature sensor 175 that detects the temperature of the battery 172, but the disclosure is not limited thereto. For example, heat exchange in the heat exchanger 176 may be controlled based on the detected value of a temperature sensor that detects the ambient temperature.

[0076] In the above embodiment, an example was shown in which the battery 172 is mounted on an electric vehicle 10, but the disclosure is not limited thereto. The battery 172 may be mounted on electrical equipment other than an electric vehicle (for example, a stationary energy storage system).

[0077] In the above embodiment, an example was shown in which the low-temperature circuit 130 is not provided with a heater, but the disclosure is not limited thereto. An electric heater may be provided in the low-temperature circuit 130 (for example, between the heat exchanger 176 and the battery 172).

[0078] The above embodiment shows an example in which five controls shown in Figures 5 to 9 are performed, but the disclosure is not limited thereto. Only some of the controls shown in Figures 5 to 9 may be performed.

[0079] In the above embodiment, an example in which a five-way valve 180 and a four-way valve 113 are used is shown, but the disclosure is not limited thereto. Multi-way valves other than five-way valves and four-way valves (for example, a six-way valve) may be used.

[0080] In the above embodiment, an example was shown in which the thermal management circuit 100 is configured to the second communication pattern shown in Figure 4 when controlling the temperature of the battery 172 using the heat exchanger 176, but the disclosure is not limited thereto. For example, the state of the thermal management circuit 100 may differ for each control shown in Figures 5 to 9. For example, in any of the cases shown in Figures 5 to 9, the thermal medium may not be flowing through the high-temperature radiator 121 or the heater core 114 in the high-temperature circuit 110.

[0081] In the above embodiment, an example was shown in which the temperature control of the battery 172 by the heat exchanger 176 is performed based on the detection of a rapid charger being found, the start of external charging, and the vehicle being driven, but the disclosure is not limited thereto. For example, the temperature control may be performed based on a predetermined operation performed by the user. Alternatively, instead of the detection of a rapid charger, the temperature control may be performed based on the SOC of the electric vehicle 10 falling below a predetermined value (for example, 50%).

[0082] In the above embodiment, an example was shown in which the battery 172 is kept warm until the scheduled departure time after external charging is complete, but the disclosure is not limited thereto. Control to raise the temperature of the battery 172 using the heat exchanger 176 may be started a predetermined time before the scheduled departure time (for example, 30 minutes before).

[0083] Furthermore, the configurations (processes) of the above embodiments and each of the above modified examples may be combined with each other.

[0084] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0085] 1 Thermal management system, 10 Electric vehicle, 100 Thermal management circuit, 110a Part (a predetermined part of the second refrigerant circuit), 112 Electric heater (heater), 113 Four-way valve (second switching valve), 121 High-temperature radiator (second radiator), 122 Low-temperature radiator (first radiator), 130 Low-temperature circuit (first refrigerant circuit), 170a Part (the part between the battery and the first switching valve), 172 Battery, 175 Temperature sensor (temperature detection unit), 176 Heat exchanger, 180 Five-way valve (first switching valve), 500 ECU (control unit).

Claims

1. A thermal management circuit having a first refrigerant circuit through which a first refrigerant flows and which includes a battery and a first radiator, and a second refrigerant circuit through which a second refrigerant different from the first refrigerant flows and which includes an electric heater, A first switching valve for switching whether the first refrigerant flows through the battery, A heat exchanger is connected to the portion of the first refrigerant circuit between the battery and the first switching valve, and to a predetermined portion of the second refrigerant circuit, and performs heat exchange between the first refrigerant and the second refrigerant. The system comprises a control device that controls the first switching valve and the electric heater, A thermal management system that controls the heat exchange between the first refrigerant and the second refrigerant in the heat exchanger by controlling the first switching valve so that the first refrigerant flows through the battery and by controlling the electric heater.

2. The second refrigerant circuit further includes a second radiator different from the first radiator, The thermal management system according to claim 1, wherein the heat exchanger is provided separately from the first radiator and the second radiator, respectively.

3. The system further includes a second switching valve for switching whether the second refrigerant flows through the heat exchanger, The heat management system according to claim 1, wherein the control device controls the second switching valve so that the second refrigerant flows through the heat exchanger when heat exchange is performed between the first refrigerant and the second refrigerant in the heat exchanger.

4. The system further includes a temperature detection unit for detecting the temperature of the aforementioned battery, The thermal management system according to any one of claims 1 to 3, wherein the control device controls the heat exchange between the first refrigerant and the second refrigerant in the heat exchanger based on the temperature of the battery detected by the temperature detection unit.

5. The thermal management system according to claim 4, wherein the control device performs a temperature rise control to raise the temperature of the battery by driving the electric heater to raise the temperature of the second refrigerant, thereby raising the temperature of the first refrigerant which exchanges heat with the second refrigerant, when the temperature of the battery detected by the temperature detection unit is lower than a threshold, thereby raising the temperature of the battery.

6. The thermal management system according to claim 5, wherein the control device performs the temperature rise control when the temperature of the battery detected by the temperature detection unit is lower than a threshold and external charging of the battery is performed.

7. The aforementioned battery is installed in an electric vehicle. The thermal management system according to claim 5, wherein the control device maintains the temperature of the battery at a predetermined temperature by performing the temperature rise control between the time the battery is charged and the time the electric vehicle starts running, when the temperature of the battery detected by the temperature detection unit is lower than a threshold.

8. The thermal management system according to claim 4, wherein the control device performs cooling control to cool the battery by stopping the operation of the electric heater and cooling the second refrigerant when the temperature of the battery detected by the temperature detection unit is higher than a threshold, thereby cooling the first refrigerant which exchanges heat with the second refrigerant.

9. A control method for a thermal management system, which includes a thermal management circuit having a first refrigerant circuit through which a first refrigerant flows and which includes a battery and a radiator, and a second refrigerant circuit through which a second refrigerant different from the first refrigerant flows and which includes an electric heater, The aforementioned thermal management system is A first switching valve for switching whether the first refrigerant flows through the battery, The system further includes a heat exchanger connected to the portion of the first refrigerant circuit between the battery and the first switching valve, and to a predetermined portion of the second refrigerant circuit, which performs heat exchange between the first refrigerant and the second refrigerant, A step of adjusting the temperature of the second refrigerant by controlling the electric heater, A control method for a thermal management system, comprising the step of controlling a first switching valve so that the first refrigerant flows through the battery so that heat exchange between the second refrigerant and the first refrigerant takes place in the heat exchanger.

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