Thermal management system

Abstract

To provide a thermal management system mounted on a hybrid vehicle which warms up a battery with excellent energy efficiency.SOLUTION: A thermal management system 1 comprises: an engine circuit 2; a battery circuit 3 with an electric heater 35; a heat exchanger 4; selector valves 23, 33 which can switch a plurality of modes to perform warming-up a battery 32; and an ECU 5 which selects a mode. An engine waste heat mode is a mode where the electric heater 35 is stopped and the engine 22 is activated to heat a heating medium. An electric heater mode is a mode where the electric heater 35 is activated to heat the heating medium. The ECU 5 selects, when temperature of the heating medium which circulates through the engine 22 is higher than the warming-up temperature of the engine, the engine waste heat mode, and selects, when the temperature of the heating medium which circulates through the engine 22 is lower than the warming-up temperature, the electric heater mode.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to thermal management systems, and more particularly, to thermal management systems installed in hybrid vehicles that include an engine and a battery. [Background technology]

[0002] The plug-in hybrid vehicle disclosed in JP 2013-38998 A (Patent Document 1) is equipped with an engine, a coolant circulation path connected to the engine and exchanging heat with the engine's waste heat to circulate coolant for cooling the engine, a radiator provided in the coolant circulation path, a secondary battery, and a traction motor driven by the electric power charged in the secondary battery. A part of the coolant circulation path is connected to the secondary battery, and the temperature of the secondary battery can be adjusted by heat exchange between the secondary battery and the coolant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-38998 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when a plug-in hybrid vehicle is plugged in for charging, the charging power is limited to protect the battery if the battery temperature is low, so the battery is warmed up. There is a demand for warming up the battery in an energy-efficient manner.

[0005] The present disclosure has been made to solve the above problems, and one of the objects of the present disclosure is to warm up a battery in an energy-efficient manner in a thermal management system mounted on a hybrid vehicle. [Means for solving the problem]

[0006] A thermal management system according to an aspect of the present disclosure is mounted on a hybrid vehicle including an engine and a battery. The thermal management system includes an engine circuit configured to circulate a first heat medium that can flow through the engine, a battery circuit configured to circulate a second heat medium that can flow through the battery and including a heater that heats the second heat medium, a heat exchanger that exchanges heat between the first heat medium and the second heat medium, a switching valve configured to be able to switch between a plurality of modes for warming up the battery, and a processor that selects one of the plurality of modes. The plurality of modes include an engine waste heat mode and a heater mode. The engine waste heat mode is a mode in which the second heat medium is warmed by operating the engine while stopping the heater while circulating both the first heat medium and the second heat medium. The heater mode is a mode in which the second heat medium is warmed by operating the heater while circulating the second heat medium while stopping the circulation of the first heat medium. The processor selects the engine waste heat mode when the temperature of the first heat medium flowing through the engine is higher than the warm-up temperature of the engine, and selects the heater mode when the temperature of the first heat medium flowing through the engine is lower than the warm-up temperature. Effect of the Invention

[0007] According to the present disclosure, in a thermal management system installed in a hybrid vehicle, it is possible to warm up a battery in an energy efficient manner. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a thermal management system according to an embodiment of the present disclosure. [Diagram 2] 4 is a diagram for explaining a plurality of battery warm-up modes in the present embodiment. FIG. [Diagram 3] 5 is a flowchart showing an example of a processing procedure of battery warm-up control in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 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 characters, and the description thereof will not be repeated.

[0010] <System configuration> 1 is a diagram showing an example of an overall configuration of a thermal management system according to an embodiment of the present disclosure. The thermal management system 1 is mounted on a plug-in hybrid vehicle (PHEV) or a hybrid vehicle (HEV), and includes an engine circuit 2, a battery circuit 3, a heat exchanger 4, and an electronic control unit (ECU) 5.

[0011] The engine circuit 2 includes a water pump (W / P) 21, an engine 22, a three-way valve 23, a radiator 24, and an engine water temperature sensor 25. The water pump 21 circulates a first heat medium (coolant) in the engine circuit 2 in accordance with a control command from the ECU 5. The engine 22 is started / stopped in accordance with a control command from the ECU 5. The three-way valve 23 is configured to selectively circulate the first heat medium to one of the radiator 24 and the heat exchanger 4 in accordance with a control command from the ECU 5. The radiator 24 releases waste heat from the engine 22 to the outside air. The engine water temperature sensor 25 detects an engine water temperature Teng, which is the temperature of the first heat medium after flowing through the engine 22, and outputs the detected value to the ECU 5.

[0012] The battery circuit 3 includes a water pump 31, a battery 32, a three-way valve 33, a radiator 34, an electric heater 35, a battery temperature sensor 36, and a battery water temperature sensor 37. The water pump 31 circulates a second heat medium (coolant) in the battery circuit 2 in accordance with a control command from the ECU 5. The battery 32 includes a battery pack (not shown) and is charged during plug-in charging of the vehicle and discharged during running of the vehicle. The three-way valve 33 is configured to selectively circulate the second heat medium to the radiator 34 and one of the electric heater 35 and the heat exchanger 4 in accordance with a control command from the ECU 5. The radiator 34 releases heat from the battery 32 that has become hot to the outside air. The electric heater 35 heats the second heat medium in accordance with a control command from the ECU 5. The battery temperature sensor 36 detects a battery temperature TB, which is the internal temperature of the battery 32 (temperature of the battery pack), and outputs the detected value to the ECU 5. The battery water temperature sensor 37 detects a battery water temperature Tbat, which is the temperature of the second heat medium after it has flowed through the battery 32, and outputs the detected value to the ECU 5.

[0013] The heat exchanger 4 exchanges heat between a first heat medium circulating through the engine circuit 2 and a second heat medium circulating through the battery circuit 3 .

[0014] The ECU 5 includes a processor and a memory. The ECU 5 generates control commands based on the detection values ​​of the above-mentioned sensors, and controls the thermal management system 1 by outputting the generated control commands to corresponding devices in the thermal management system 1. The ECU 5 has a plurality of "battery warm-up modes" for warming up the battery 32 during plug-in charging of the vehicle, etc.

[0015] <Battery warm-up mode> 2 is a diagram for explaining a plurality of battery warm-up modes in this embodiment. The plurality of battery warm-up modes include an electric heater mode, an engine waste heat mode, and a combined mode.

[0016] The electric heater mode is a mode in which the second heat medium is heated by operating the electric heater 35 while circulating the second heat medium in the battery circuit 3 while stopping the circulation of the first heat medium in the engine circuit 2. The engine 22 may be running or stopped. In the electric heater mode, a path is formed through which the second heat medium flows in the following order: water pump 31 - heat exchanger 4 - electric heater 35 (operating) - three-way valve 33 - battery 32 - water pump 31.

[0017] The engine waste heat mode is a mode in which the second heat medium is heated by circulating both the first heat medium in the engine circuit 2 and the second heat medium in the battery circuit 3, stopping the electric heater 35 and driving the engine 22. In the engine waste heat mode, a path is formed through which the first heat medium flows in the order of the water pump 21-engine 22 (driven)-three-way valve 23-heat exchanger 4-water pump 21, and a path is formed through which the second heat medium flows in the order of the water pump 31-heat exchanger 4-electric heater 35 (stopped)-three-way valve 33-battery 32-water pump 31.

[0018] The combined mode is a mode in which the second heat medium is heated by operating the electric heater 35 and driving the engine 22 while circulating both the first heat medium in the engine circuit 2 and the second heat medium in the battery circuit 3. In the combined mode, a path is formed in which the first heat medium flows in the order of the water pump 21-engine 22 (driven)-three-way valve 23-heat exchanger 4-water pump 21, and a path is formed in which the second heat medium flows in the order of the water pump 31-heat exchanger 4-electric heater 35 (operated)-three-way valve 33-battery 32-water pump 31.

[0019] <Processing flow> 3 is a flowchart showing an example of a procedure for battery warm-up control in this embodiment. The process shown in this flowchart is executed by the ECU 5 when a predetermined condition is met (for example, at predetermined intervals). Hereinafter, step is abbreviated as S.

[0020] In S1, the ECU 5 determines whether the battery temperature TB detected by the battery temperature sensor 36 is lower than a predetermined threshold temperature TH (for example, 0° C.). If the battery temperature TB is equal to or higher than the threshold temperature TH (NO in S1), the electric heater 35 is stopped and warming up of the battery 32 is not executed (S9). If the battery temperature TB is lower than the threshold temperature TH (YES in S1), the ECU 5 advances the process to S2.

[0021] In S2, the ECU 5 determines whether the vehicle (in this example, a plug-in hybrid vehicle) is being charged. If the vehicle is being charged (YES in S2), the ECU 5 proceeds to S3 and determines whether the battery water temperature Tbat detected by the battery water temperature sensor 37 is higher than the engine water temperature Teng detected by the engine water temperature sensor 25.

[0022] If the battery water temperature Tbat is higher than the engine water temperature Teng (YES in S3), the ECU 5 selects the electric heater mode (S6). On the other hand, if the battery water temperature Tbat is equal to or lower than the engine water temperature Teng (NO in S3), the ECU 5 selects the combined mode (S7).

[0023] If the vehicle is not being charged in S2 (NO in S2), for example, if the vehicle is running, the ECU 5 proceeds to S4 and determines whether the engine 22 is being driven. If the engine 22 is being driven (YES in S4), the ECU 5 determines whether the warm-up of the engine 22 is complete (S5). Whether the warm-up of the engine 22 is complete can be determined based on, for example, the engine water temperature Teng. If the warm-up of the engine 22 is complete (YES in S5), the ECU 5 selects the engine waste heat mode (S8).

[0024] If the engine 22 is stopped (NO in S4), or if the engine 22 is started but is in the middle of warming up and has not yet been completed (NO in S5), the ECU 5 advances the process to S6 and selects the electric heater mode.

[0025] As described above, in the engine waste heat mode and combined use mode in this embodiment, the waste heat of the engine 22 generated in the engine circuit 2 is transferred to the battery circuit 3 via the heat exchanger 4, so that the waste heat of the engine 22 can be used to warm up the battery 32. This makes it possible to reduce the amount of power consumed by the electric heater 35 compared to a case in which the waste heat of the engine 22 is not used. Therefore, according to this embodiment, the battery 32 can be warmed up with energy efficiency.

[0026] 1 and 2 are merely examples. Although not shown, for example, the three-way valve 33 and the radiator 34 may not be provided in the battery circuit 3 (another embodiment 1). In the battery circuit 3, a chiller may be provided instead of the radiator 34, and a compressor and an air-cooled condenser, which are other components of the refrigeration cycle, may be provided (another embodiment 2). Also, a chiller may be provided instead of the radiator 34 of the battery circuit 3, and a water-cooled condenser that exchanges heat with the engine circuit 2 and a compressor may be provided (another embodiment 3).

[0027] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0028] 1 thermal management system, 2 engine circuit, 21 water pump, 22 engine, 23 three-way valve, 24 radiator, 25 engine water temperature sensor, 3 battery circuit, 31 water pump, 32 battery, 33 three-way valve, 34 radiator, 35 electric heater, 36 battery temperature sensor, 37 battery water temperature sensor, 4 heat exchanger, 5 ECU.

Claims

[Claim 1] A thermal management system for a vehicle including an engine and a battery, comprising: an engine circuit configured to circulate a first heat transfer medium capable of flowing through the engine; a battery circuit configured to circulate a second heat medium capable of flowing through the battery, the battery circuit including a heater that heats the second heat medium; a heat exchanger that exchanges heat between the first heat medium and the second heat medium; A switching valve configured to be able to switch between a plurality of modes for warming up the battery; a processor for selecting one of the plurality of modes; The plurality of modes include: an engine waste heat mode in which the second heat medium is heated by circulating both the first heat medium and the second heat medium and stopping the heater while driving the engine; a heater mode in which the second heat medium is heated by operating the heater while stopping circulation of the first heat medium and circulating the second heat medium, The processor, When the temperature of the first heat medium flowing through the engine is higher than a warm-up temperature of the engine, the engine waste heat mode is selected; A thermal management system that selects the heater mode when a temperature of the first heat medium flowing through the engine is lower than the warm-up temperature.

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