Vehicle thermal management system

Abstract

This device raises the battery temperature while suppressing the power consumption of the electric heater. [Solution] The battery heat circuit 120 receives heat from the high-temperature side heat transfer medium flowing through the flow path 110g of the HT heat circuit 110 in the heat exchanger 140, and raises the temperature of the battery 200. The flow path 110a (first heat circuit) of the HT heat circuit 110 contains an electric pump 111 (first electric pump) and an internal combustion engine 300. The flow path 110e of the HT heat circuit 110 contains an electric pump 115 (second electric pump) and an electric heater 116. When there is a request to raise the temperature of the battery 200, if the temperature THW of the high-temperature side heat transfer medium in the flow path 110a is above a predetermined temperature A, the electric pump 111 is activated and ports P2 and P3 of the four-way valve 400 are connected. If the temperature THW is below the predetermined temperature A, the electric pump 115 is activated and the electric heater 116 is energized and ports P1 and P3 of the four-way valve 400 are connected.

Description

Technical Field

[0001] The present disclosure relates to a thermal management device for a vehicle.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2024-133774 (Patent Document 1) discloses a battery temperature adjustment system for a hybrid vehicle equipped with an engine and a vehicle drive motor. In this battery temperature adjustment system, when the hybrid vehicle is running in HV mode and the vehicle interior is in a heating state, in addition to the engine-driven pump, an electric pump provided in the engine cooling water circuit is operated to circulate the engine cooling water through the water-water heat exchanger to warm the battery. When the vehicle interior is not in a heating state, the engine-driven pump circulates the engine cooling water through the water-water heat exchanger to warm the battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery temperature adjustment system of Patent Document 1, when the engine-driven pump is stopped (when the engine is stopped), it is difficult to warm the battery with the engine cooling water. When the engine is stopped, even if the temperature of the engine cooling water is relatively high, an electric heater (water heater) is operated to warm the battery. Therefore, there has been a concern that the power consumption of the electric heater becomes relatively large.

[0005] An object of the present disclosure is to increase the temperature of the battery while suppressing the power consumption of the electric heater.

Means for Solving the Problems

[0006] The thermal management device for a vehicle according to this disclosure is a thermal management device for a vehicle equipped with an internal combustion engine, a motor, and a battery which is the power source for the motor. The thermal management device includes a battery thermal circuit through which a heat transfer medium circulates to regulate the temperature of the battery, a first thermal circuit that cools the internal combustion engine using a heat transfer medium circulated by a first electric pump, a second thermal circuit in which a heat transfer medium circulated by a second electric pump is heated by an electric heater, and a heat exchanger that performs heat exchange between the heat transfer medium flowing through the first thermal circuit, the heat transfer medium flowing through the second thermal circuit, and the heat transfer medium circulating through the battery thermal circuit. When there is a request to raise the temperature of the battery, if the temperature of the heat transfer medium in the first thermal circuit is above a predetermined temperature, the thermal management device drives the first electric pump to perform heat exchange between the heat transfer medium in the first thermal circuit and the heat transfer medium in the battery thermal circuit. When the thermal management device receives a request to raise the temperature of the battery, if the temperature of the heat transfer medium in the first thermal circuit is below a predetermined temperature, it drives the second electric pump and energizes the electric heater to perform heat exchange between the heat transfer medium in the second thermal circuit and the heat transfer medium in the battery thermal circuit.

[0007] After an internal combustion engine has warmed up, even if the engine is stopped, the temperature of the heat transfer medium (coolant temperature) used to cool the engine may be relatively high. With this configuration, when there is a request to raise the battery temperature, if the temperature of the heat transfer medium in the first heat circuit that cools the internal combustion engine is above a predetermined temperature, the first electric pump is driven to perform heat exchange between the heat transfer medium in the first heat circuit and the heat transfer medium in the battery heat circuit. When there is a request to raise the battery temperature, if the temperature of the heat transfer medium in the first heat circuit that cools the internal combustion engine is below a predetermined temperature, the second electric pump is driven and the electric heater is energized to perform heat exchange between the heat transfer medium in the second heat circuit and the heat transfer medium in the battery heat circuit. As a result, even if the internal combustion engine is stopped, the battery can be heated using the waste heat from the internal combustion engine, and if the waste heat from the internal combustion engine cannot be used, the battery can be heated using the electric heater. Therefore, the battery can be heated while suppressing the power consumption of the electric heater.

[0008] Preferably, the electric heater may be powered using the battery, which is the power source for the motor. Since the power consumption of the electric heater is suppressed, the deterioration of the vehicle's driving range due to the battery overheating can be suppressed.

[0009] Preferably, the vehicle is equipped with an air conditioning system for heating the interior, and the heat transfer medium flowing through the first and second heat circuits may be used for heating. With this configuration, the electric heater used for heating can be used to raise the temperature of the battery. [Effects of the Invention]

[0010] According to this disclosure, the battery can be heated while suppressing the power consumption of the electric heater. [Brief explanation of the drawing]

[0011] [Figure 1] This figure shows a schematic configuration of a vehicle thermal management device according to an embodiment of the present disclosure. [Figure 2] This flowchart shows an example of the battery temperature rise control process performed by the ECU. [Figure 3] This diagram illustrates how to raise the temperature of a battery using waste heat from an internal combustion engine. [Figure 4] This diagram illustrates how to raise the temperature of a battery using an electric heater. [Modes for carrying out the invention]

[0012] Embodiments of this 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 descriptions will not be repeated.

[0013] Figure 1 shows a schematic configuration of the thermal management device 10 of the vehicle 1 according to this embodiment. The vehicle 1 is a hybrid electric vehicle (HEV) equipped with a battery 200, an internal combustion engine 300, and a drive motor (motor generator: MG) 134. The vehicle 1 in this embodiment is a plug-in hybrid electric vehicle (PHEV) in which the battery 200 can be charged externally, but it may also be an HEV in which the battery 200 is not externally charged.

[0014] The thermal management device 10 comprises a thermal management circuit 100 and an ECU (Electronic Control Unit) 500. The ECU 500 includes a processor 501 and a memory 502. The processor 501 executes a program stored in the memory 502, thereby performing various thermal management controls in the ECU 500. The ECU 500 controls the electric pumps 111, 115, 121, 131, the four-way valve 400, etc., which will be described later.

[0015] The thermal management device 10 is configured to manage the thermal energy of the vehicle 1 using the heat transfer medium of the thermal management circuit 100. The thermal management circuit 100 includes an HT thermal circuit 110, a battery thermal circuit 120, an LT thermal circuit 130, a refrigeration cycle 150, and a control device 500.

[0016] The HT heat circuit 110 includes a flow path through which the high-temperature heat transfer medium flows and circulates. The HT heat circuit 110 includes an electric pump 111, a high-temperature radiator 112, a thermostat 113, a heater core 114, an electric pump 115, and an electric heater 116. The HT heat circuit 110 also includes an internal combustion engine 300 and a four-way valve 400. The high-temperature heat transfer medium may be cooling water such as LLC (Long Life Coolant). The high-temperature heat transfer medium exchanges heat with each piece of equipment as it passes through them. The four-way valve 400 has ports P1 to P4 and corresponds to an example of a "switching valve" in this disclosure.

[0017] An electric pump 111 and an internal combustion engine 300 are provided in the flow path 110a connected to the thermostat 113. When the electric pump 111 operates, the high-temperature heat transfer medium flows through the internal combustion engine 300. The flow path 110a downstream of the internal combustion engine 300 branches into two flow paths, 110b and 110c. A high-temperature radiator 112 is provided in flow path 110b, and the downstream side of the high-temperature radiator 112 merges with the thermostat 113. Flow path 110c is connected to port P2 of the four-way valve 400 and also branches into a bypass flow path 110d. The bypass flow path 110d merges with the thermostat 113 via a merging flow path 110h.

[0018] The electric pump 115 and the electric heater 116 are provided in the flow path 110e. When the electric pump 115 operates, the high-temperature side heat medium flows through the electric heater 116. The flow path 110e on the downstream side of the electric heater 116 is connected to the port P1 of the four-way valve 400.

[0019] The port P4 of the four-way valve 400 is connected to the flow path 110f. A heater core 114 is arranged in the flow path 110f, and the flow path 110f on the downstream side of the heater core 114 is connected to the confluence path 110h. The heater core 114 is used as a heat source for the heating source of the air conditioner 2.

[0020] A flow path 110g is connected to the port P3 of the four-way valve 400. The flow path 110g is connected to the heat exchanger 140, and the flow path 110g on the downstream side of the heat exchanger 140 is connected to the confluence path 110h.

[0021] The battery thermal circuit 120 includes a flow path through which the heat medium flows and circulates. The heat medium of the battery thermal circuit 120 may be insulating oil or an insulating antifreeze. An electric pump 121, a battery 200, a heat exchanger 140, and a chiller 160 are arranged in the flow path of the battery thermal circuit 120. The electric pump 121 circulates the heat medium in the battery thermal circuit 120. The heat medium exchanges heat with each device when passing through. When the heat medium circulates in the battery thermal circuit 120, the heat exchanger 140 can receive the heat of the high-temperature side heat medium and raise the temperature of the battery 200. Also, in the chiller 160, the heat of the heat medium in the battery thermal circuit 120 can be absorbed to cool the battery 200. The temperature of the battery 200 can be adjusted by the heat medium circulating in the battery thermal circuit 120.

[0022] The LT heat circuit 130 includes a flow path through which the low-temperature side heat medium flows and circulates. The LT heat circuit 130 includes an electric pump 131, an ESU (Electricity Supply Unit) 132, a PCU (Power Control Unit) 133, an MG 134, and a low-temperature radiator 135. The electric pump 131 circulates the low-temperature side heat medium in the LT heat circuit 130. The low-temperature side heat medium may be cooling water such as LLC (Long Life Coolant). The low-temperature side heat medium exchanges heat with each device when passing through each device. When there is a cooling requirement for the ESU 132, the PCU 133, and the MG 134, the electric pump 131 operates to cool the ESU 132, the PCU 133, and the MG 134.

[0023] Refrigerant circulates in the refrigeration cycle 150. The refrigeration cycle 150 includes a compressor 151, a condenser 152, an electric expansion valve 153, an evaporator 154, an evaporative pressure regulator (EPR) 155, and an electric expansion valve 156. The compressor 151 compresses and discharges the refrigerant flowing out of the chiller 160. The evaporator 154 is used as a cooling source for the air conditioner 2. The chiller 160 is connected to both the refrigeration cycle 150 and the battery heat circuit 120 and functions as a heat exchanger. Heat exchange occurs between the refrigerant circulating in the refrigeration cycle 150 and the heat medium flowing in the battery heat circuit 120 by the chiller 160. When there is a cooling requirement for the battery 200, the heat medium in the battery heat circuit 120 is cooled by the chiller 160 to cool the battery 200.

[0024] The air conditioner 2 performs heating by heat dissipation from the heater core 114 and performs cooling using the evaporator 154 as a cooling source. The high-temperature radiator 112, the low-temperature radiator 135, and the condenser 152 are provided in front of the vehicle 1, and heat exchange (cooling) is efficiently performed by the running wind of the vehicle 1.

[0025] Electric pumps 111, 115, and 121 are powered by an auxiliary battery (not shown). Electric pump 111 corresponds to an example of the “first electric pump” of this disclosure, and electric pump 115 corresponds to an example of the “second electric pump” of this disclosure. The electric heater 116 is powered by the battery 200. The hybrid system of vehicle 1 may be series, parallel, or series-parallel. The MG134, which is the drive motor of vehicle 1, is powered by the battery 200. Alternatively, the battery 200 and an auxiliary battery may be connected via a DC-DC converter, and the power of the auxiliary battery may be supplied by the power of the battery 200.

[0026] When the internal combustion engine 300 is in operation, if there is no heating request from the air conditioning unit 2 and no temperature increase request from the battery 200, ports P1 and P2 of the four-way valve 400 are closed. Then, the electric pump 111 operates, and the high-temperature heat transfer medium (LLC) flows through the cylinder block (cooling water passage) of the internal combustion engine 300. The thermostat 113 remains closed until the internal combustion engine 300 has finished warming up, and the high-temperature heat transfer medium circulates through passages 110a, 110c, and bypass passage 110d. When the internal combustion engine 300 has finished warming up and the temperature of the high-temperature heat transfer medium reaches a predetermined temperature (for example, 85°C), the thermostat 113 opens. Then, the high-temperature heat transfer medium that has cooled the internal combustion engine 300 flows through passage 110b, where heat exchange (heat dissipation) takes place in the high-temperature radiator 112, preventing the internal combustion engine 300 from overheating. The HT thermal circuit 110, which includes the flow path 110a, corresponds to an example of the "first thermal circuit" in this disclosure.

[0027] When the internal combustion engine 300 is in operation and there is a heating request from the air conditioning unit 2, ports P2 and P4 of the four-way valve 400 are connected, and the high-temperature heat transfer medium circulated by the electric pump 111 flows through the flow path 110f. As a result, the heat from the high-temperature heat transfer medium heated by the internal combustion engine 300 is released from the heater core 114 to provide heating.

[0028] When there is a heating request from the air conditioning unit 2, ports P1 and P4 of the four-way valve 400 are connected when the internal combustion engine 300 is stopped or when the temperature of the high-temperature heat transfer medium flowing through the flow path 110a is low. Then, the electric pump 115 is activated and the electric heater 116 is energized. As a result, the high-temperature heat transfer medium flowing through the flow path 110e is heated by the electric heater 116, flows through the flow path 110f, and provides heating through heat dissipation from the heater core 114. The HT heat circuit 110 including the flow path 110e corresponds to an example of the "second heat circuit" of this disclosure.

[0029] Figure 2 is a flowchart showing an example of the battery temperature rise control process performed by the ECU 500. This process is repeated at predetermined intervals whenever there is a request for the battery 200 to rise in temperature. A request for the battery 200 to rise in temperature occurs when the battery temperature TB detected by the monitoring unit 13 (see Figure 1) is below the set temperature. The set temperature may be, for example, 5°C, or it may be 0°C or 10°C.

[0030] In step 10 (hereinafter, step will be abbreviated as "S"), the electric pump 121 is activated. When the electric pump 121 is activated, the heat transfer medium in the battery heat circuit 120 circulates, and the heat exchanger 140 receives heat from the high-temperature side heat transfer medium, making it possible to raise the temperature of the battery 200.

[0031] In the subsequent S20, it is determined whether the temperature THW of the high-temperature heat transfer medium flowing through the flow path 110a is equal to or greater than a predetermined temperature A. The temperature THW may be detected by a temperature sensor 12 installed at the outlet of the flow path 110a of the internal combustion engine 300. The temperature THW corresponds to the coolant temperature of the internal combustion engine 300. The predetermined temperature A may be, for example, 50°C. The predetermined temperature A may also be set according to the battery temperature TB, and may be set to a value higher than the battery temperature TB. If the temperature THW is equal to or greater than the predetermined temperature A, it is determined to be positive and the process proceeds to S30. If the temperature THW is less than the predetermined temperature A, it is determined to be negative and the process proceeds to S40.

[0032] In S30, the electric pump 111 is activated and P2 and P3 of the four-way valve 400 are connected. While the electric pump 111 is operating, its operation is continued. Figure 3 illustrates the raising of the battery 200 using the waste heat of the internal combustion engine 300. When the electric pump 111 is activated and P2 and P3 of the four-way valve 400 are connected, the high-temperature side heat transfer medium circulates through the HT heat circuit, which includes the flow path 110a and the flow path 110g, as shown by the dashed line in Figure 3. The heat transfer medium in the battery heat circuit 120 receives heat from the high-temperature side heat transfer medium heated by the internal combustion engine 300 in the heat exchanger 140, raising the temperature of the battery 200. In this way, the battery 200 can be raised using the waste heat of the internal combustion engine 300.

[0033] In S40, the electric pump 115 is activated and the electric heater 116 is energized. Then, P1 and P3 of the four-way valve 400 are connected. Figure 4 is a diagram illustrating the heating of the battery 200 using the electric heater 116. When the electric pump 115 is activated, the electric heater 116 is energized, and P1 and P3 of the four-way valve 400 are connected, the high-temperature side heat transfer medium circulates through the HT heat circuit, which includes the flow path 110e and the flow path 110g, as shown by the dashed line in Figure 4. The heat transfer medium in the battery heat circuit 120 receives heat from the high-temperature side heat transfer medium heated by the electric heater 116 in the heat exchanger 140, and heats up the battery 200. In this way, the battery 200 can be heated using the electric heater 116.

[0034] The battery temperature rise control shown in Figure 2 is continuously processed when the battery temperature TB is below the set temperature and a temperature rise request for battery 200 is received. Processing ends when the battery temperature TB exceeds the set temperature and the temperature rise request is cancelled.

[0035] According to this embodiment, when there is a request to raise the temperature of the battery 200, if the temperature THW of the high-temperature side heat transfer medium in the HT heat circuit 110, which includes a flow path 110a for cooling the internal combustion engine 300, is above a predetermined temperature A, the electric pump 111 is driven to perform heat exchange between the high-temperature side heat transfer medium in the flow path 110a and the heat transfer medium in the battery heat circuit 120. If the temperature THW is below the predetermined temperature A, the electric pump 115 is driven and the electric heater 116 is energized to perform heat exchange between the high-temperature side heat transfer medium in the flow path 110e and the heat transfer medium in the battery heat circuit 120. As a result, even when the internal combustion engine 300 is stopped, the battery 200 can be heated using the waste heat of the internal combustion engine 300, and when the waste heat of the internal combustion engine 300 cannot be used, the battery 200 can be heated using the electric heater 116. Therefore, the battery 200 can be heated while suppressing the power consumption of the electric heater 116. The electric heater 116 is powered using the power from the battery 200, which is the power source for the MG 134. Since the power consumption of the electric heater 116 is suppressed, the deterioration of the vehicle's range due to the temperature rise of the battery 200 can be suppressed.

[0036] According to this embodiment, the high-temperature heat transfer medium flowing through the flow paths 110a and 110e is used for heating the air conditioning unit 2. The electric heater 116 used for heating can also be used to raise the temperature of the battery 200.

[0037] Furthermore, if there is a heating request from the air conditioning unit 2 and a temperature increase request from the battery 200, when the temperature THW is low, ports P1, P3, and P4 of the four-way valve 400 may be connected to activate the electric pump 115 and energize the electric heater 116. When the temperature THW is high, or when the internal combustion engine 300 is in operation, the electric pump 111 may be activated (or kept running) and ports P2, P3, and P4 of the four-way valve 400 may be connected.

[0038] 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]

[0039] 1 Vehicle, 2 Air conditioning system, 100 Thermal control circuit, 110 HT thermal circuit, 111 Electric pump, 115 Electric pump, 116 Electric heater, 120 Battery thermal circuit, 130 LT thermal circuit, 140 Heat exchanger, 150 Refrigeration cycle, 200 Battery, 300 Internal combustion engine, 400 Four-way valve, 500 ECU.

Claims

1. A thermal management device for a vehicle comprising an internal combustion engine, a motor, and a battery which is the power source for the motor, A battery thermal circuit in which a heat transfer medium circulates and regulates the temperature of the battery, A first thermal circuit that cools the internal combustion engine using a heat transfer medium circulated by a first electric pump, A second heat circuit in which a heat transfer medium circulated by a second electric pump is heated by an electric heater, The system includes a heat exchanger that performs heat exchange between the heat transfer medium flowing through the first heat circuit, the heat transfer medium flowing through the second heat circuit, and the heat transfer medium circulating through the battery heat circuit. When there is a request for the aforementioned battery to heat up, When the temperature of the heat transfer medium in the first heat circuit is above a predetermined temperature, the first electric pump is driven to perform heat exchange between the heat transfer medium in the first heat circuit and the heat transfer medium in the battery heat circuit. A vehicle thermal management device that, when the temperature of the heat transfer medium in the first thermal circuit is below the predetermined temperature, drives the second electric pump and energizes the electric heater to perform heat exchange between the heat transfer medium in the second thermal circuit and the heat transfer medium in the battery thermal circuit.

2. The vehicle thermal management device according to claim 1, wherein the electric heater is powered using the power of the battery.

3. It is further equipped with an air conditioning system to heat the interior of the vehicle. The thermal management device for a vehicle according to claim 1 or 2, wherein the heat transfer medium flowing through the first thermal circuit and the second thermal circuit is used for heating.

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