Battery heating system

Abstract

To provide a battery temperature raising system which can enhance ability to raise temperature of a battery.SOLUTION: A battery temperature raising system 10 raises temperature of a battery 12 mounted on a vehicle, and comprises: a battery cooling water circuit 20 configured to cool or heat the battery 12 to an appropriate temperature; and an engine cooling water circuit 30 which cools an engine 11 and includes a battery temperature raising path 32 for heating the battery cooling water circuit 20, a heater core path 33 for heating air blown into a vehicle compartment and a heater path 34 for heating by a heater 45. The battery temperature raising path 32 and the heater core path 33 are connected in parallel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery warming system for warming a battery mounted on a vehicle. [Background technology]

[0002] The charge amount of a battery installed in a vehicle is limited at low temperatures to prevent deterioration of characteristics and shorten its lifespan. Therefore, by raising the temperature of the battery during charging, the battery charging efficiency is improved and the charging time is shortened. For example, Patent Document 1 discloses a technology that uses engine waste heat in an engine coolant circuit to heat the battery to an appropriate temperature. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-222027 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the engine coolant circuit disclosed in Patent Document 1, a battery heat exchanger that heats the battery to an appropriate temperature and a heater core that heats the air to be blown into the vehicle cabin are connected in series. Therefore, in this engine coolant circuit, the heater core acts as a resistance when circulating the coolant through the battery heat exchanger, making it difficult to ensure a sufficient flow rate of the coolant to the battery heat exchanger, and the battery may not be heated sufficiently.

[0005] Therefore, an object of the present invention is to provide a battery warming system that can improve the ability to warm up a battery. [Means for solving the problem]

[0006] The battery heating system of the present invention is a battery heating system that heats a battery mounted on a vehicle, and is characterized in that it has a battery coolant circuit that cools or heats the battery to an appropriate temperature, a first path that heats the battery coolant circuit, a second path that heats the air blown into the vehicle cabin, and a third path that is heated by a heater, and an engine coolant circuit that cools the engine, and the first path and second path are connected in parallel.

[0007] With the above configuration, the resistance of the first path that heats the battery coolant circuit is reduced, and a sufficient flow rate of the first path can be ensured, thereby improving the ability to heat the battery.

[0008] In the battery warming system according to the present invention, the third path is preferably connected in series with the first path and the second path, and a bypass path that bypasses the third path is preferably provided.

[0009] With the above configuration, the resistance of the first path that heats the battery coolant circuit is reduced, and a sufficient flow rate of the first path can be ensured, thereby improving the ability to heat the battery.

[0010] In the battery heating system of the present invention, when the battery temperature is below a predetermined temperature and the water temperature of the engine coolant circuit is higher than the battery temperature, it is preferable to heat the battery coolant circuit using only the exhaust heat from the engine, and when the battery temperature is below the predetermined temperature and the difference between the water temperature of the engine coolant circuit and the battery temperature is below the predetermined temperature, to heat the battery coolant circuit using heat from a heater.

[0011] With the above configuration, the battery can be efficiently heated by heating it with the heater after it has been heated by the exhaust heat of the engine in the engine coolant circuit. [Effects of the Invention]

[0012] According to the battery warming system of the present invention, the ability to warm up the battery can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a circuit diagram illustrating a battery warming system according to an embodiment; [Figure 2] FIG. 10 is a circuit diagram showing a case where the temperature of the battery is increased only by exhaust heat from the engine. [Figure 3] FIG. 10 is a circuit diagram showing a case where the temperature of the battery is increased by exhaust heat from an engine and heating by a heater. [Figure 4] FIG. 10 is a circuit diagram showing a case where the temperature of the battery is increased only by a heater. [Figure 5] FIG. 2 is a block diagram showing the configuration of a control unit. [Figure 6] FIG. 4 is a flowchart showing the flow of battery temperature increase control. DETAILED DESCRIPTION OF THE INVENTION

[0014] An example of an embodiment of the present invention will be described in detail below. In the following description, specific shapes, materials, directions, numerical values, etc. are examples for facilitating understanding of the present invention, and can be appropriately changed according to the application, purpose, specifications, etc.

[0015] The battery warming system 10 is a system that warms up a battery 12 mounted on a vehicle (not shown). The battery warming system 10 can improve the ability to warm up the battery 12, as will be described in detail later.

[0016] The vehicle of this embodiment is a hybrid electric vehicle (HEV) that runs by driving an engine 11 and a motor (not shown). The motor receives power from a battery 12.

[0017] [Battery heating system] The configuration of a battery warming system 10 as an example of an embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0018] The battery warming system 10 has a battery coolant circuit 20 that cools or heats the battery 12 to an appropriate temperature by circulating coolant, an engine coolant circuit 30 that cools the engine 11 by circulating coolant (and at the same time heats the battery 12 with the exhaust heat of the engine 11), and an ECU (Electronic Control Unit) 50 as a control unit that controls each device in the battery coolant circuit 20 and the engine coolant circuit 30.

[0019] [Battery cooling water circuit] The battery coolant circuit 20 cools or heats the battery 12 to an appropriate temperature by circulating heated or cooled coolant through a battery heat exchanger 21 provided adjacent to the battery 12. The battery coolant circuit 20 has the above-mentioned battery heat exchanger 21, a pump 22, a chiller 23, and a water-water heat exchanger 24, each of which will be described in detail later.

[0020] The pump 22 circulates the coolant in the battery coolant circuit 20. The chiller 23 is connected to a refrigeration cycle circuit (not shown) and cools the water circulating in the battery coolant circuit 20 by the refrigerant circulating in the refrigeration cycle circuit.

[0021] The water-water heat exchanger 24 exchanges heat between the coolant circulating through the engine coolant circuit 30 and the coolant circulating through the battery coolant circuit 20. More specifically, the water-water heat exchanger 24 heats the coolant circulating through the battery coolant circuit 20 with the coolant circulating through the engine coolant circuit 30.

[0022] With the above configuration, in the battery coolant circuit 20, the coolant circulated by the pump 22 is heated by the water-water heat exchanger 24, thereby heating the battery heat exchanger 21 and heating the battery 12 to an appropriate temperature. Also, in the battery coolant circuit 20, the coolant circulated by the pump 22 is cooled by the chiller 23, thereby cooling the battery heat exchanger 21 and cooling the battery 12.

[0023] [Engine cooling water circuit] The engine coolant circuit 30 cools the engine 11 by circulating the coolant, heats the coolant circulating in the battery coolant circuit 20 by circulating the coolant, heats the air blown into the vehicle cabin by circulating the coolant, and the coolant is heated by the heater 45.

[0024] The engine coolant circuit 30 has an engine cooling path 31 that cools the engine 11, a battery heating path 32 as a first path that heats the battery coolant circuit 20, a heater core path 33 as a second path that heats the air to be blown into the vehicle cabin, a heater path 34 as a third path that is heated by a heater 45, a heater bypass path 35 as a bypass path that bypasses the heater path 34, and an engine bypass path 36 that bypasses the engine 11.

[0025] The engine cooling path 31 cools the engine 11 by circulating coolant through cooling passages formed in the cylinder head and cylinder block of the engine 11 using a pump (not shown) driven by the power of the engine 11. A radiator 13 is connected in parallel to the engine cooling path 31, and a three-way valve having a thermostat 41 circulates the coolant through the radiator 13 to cool the coolant when the coolant is at a predetermined temperature or higher. Furthermore, a flow shutting valve 42 that opens and closes the engine cooling path 31 is provided downstream of the engine 11.

[0026] The battery heating path 32, which serves as the first path, heats the coolant circulating through the battery coolant circuit 20. The battery heating path 32 is provided with the above-mentioned water-water heat exchanger 24, which is connected to the battery coolant circuit 20. The battery heating path 32 is connected downstream of the engine cooling path 31 and connected in parallel to the heater core path 33. A three-way adjustment valve 43 is provided at the branch point between the battery heating path 32 and the heater core path 33. The three-way adjustment valve 43 can adjust the flow rate from the engine cooling path 31 to the battery heating path 32 and the flow rate from the engine cooling path 31 to the heater core path 33.

[0027] In the engine coolant circuit 30, the battery heating path 32 and the heater core path 33 are connected in parallel, so that the coolant circulating through the battery heating path 32 does not encounter resistance from the heater core 44 (described later). This ensures a sufficient amount of coolant circulating through the battery heating path 32, improving the ability to heat the battery 12.

[0028] The heater core path 33, which serves as the second path, heats the air to be blown into the vehicle cabin. A heater core 44 is provided in the heater core path 33 to heat the air to be blown into the vehicle cabin in an air conditioning device that conditions the air inside the vehicle cabin. The heater core path 33 is connected downstream of the engine cooling path 31 and in parallel with the battery heating path 32.

[0029] The heater path 34, which serves as a third path, is heated by a heater 45. The heater path 34 is provided with the heater 45 and a pump 46. The heater path 34 is connected in series with the battery temperature rise path 32 and the heater core path 33, and is connected downstream of the battery temperature rise path 32 and the heater core path 33.

[0030] The heater bypass path 35, which serves as a bypass path, is connected in parallel with the heater path 34 and bypasses the heater path 34. As will be described in detail later, the heater bypass path 35 ensures a sufficient amount of cooling water circulating through the battery heating path 32, thereby improving the ability to heat the battery 12. In addition, an increase in the power consumption of the heater 45 can be suppressed.

[0031] The engine bypass path 36 is a path that bypasses the engine 11, and connects the engine cooling path 31 and the heater path 34. A three-way switching valve 47 is provided at the connection between the engine bypass path 36 and the heater path 34. The three-way switching valve 47 switches between communication between the engine bypass path 36 and the heater path 34 and communication between the heater path 34 and the engine cooling path 31.

[0032] [Mode 1 (engine exhaust heat only)] 2 , in the engine coolant circuit 30, the battery coolant circuit 20 and / or the heater core 44 may be heated only by the exhaust heat of the engine 11 (hereinafter referred to as the first mode). In the first mode, the flow shutting valve 42 is opened, the three-way regulating valve 43 is adjusted based on the heating load of the air conditioner and the battery temperature, the pump 46 is stopped, and the three-way switching valve 47 is switched to communicate between the heater path 34 and the engine cooling path 31. In the first mode, the coolant is heated by the exhaust heat of the engine 11, heats the heater core 44 and / or the water-to-water heat exchanger 24, and returns to the engine 11 via the heater bypass path 35.

[0033] According to the first mode, most of the circulating coolant does not pass through the heater path 34 and is not subjected to the resistance of the heater 45 and the pump 46. Therefore, a sufficient amount of coolant can be ensured to circulate through the battery heating path 32, thereby improving the ability to heat the battery 12.

[0034] Here, since the heater path 34 has a higher resistance than the heater bypass path 35, a smaller amount of cooling water flows through the heater path 34 as compared to the heater bypass path 35.

[0035] For example, in the first mode, when coolant is not circulating through the heater path 34, the coolant remaining in the heater path 34 may be cooled by the outside air temperature. In this state, when the first mode is switched to the second mode (described later), the coolant remaining in the heater path 34 needs to be heated by the heater 45, which increases the power consumption of the heater 45. Furthermore, when the first mode is switched to the second mode, the coolant remaining and cooled in the heater path 34 may flow into the heater core path 33, which may result in the heater core 44 not being heated sufficiently, thereby decreasing the temperature of the air discharged from the air conditioner during heating.

[0036] However, in the engine coolant circuit 30 of this embodiment, in the first mode, even a small amount of coolant heated by the exhaust heat of the engine 11 circulates through the heater path 34, and when the mode is shifted from the first mode to the second mode, the increase in power to the heater 45 described above can be suppressed. Also, when the mode is shifted from the first mode to the second mode, the heater core 44 is sufficiently heated, so that the temperature of the air blown out during heating by the air conditioner does not decrease.

[0037] In the first mode, the three-way regulating valve 43 is adjusted based on the heating load of the air conditioner and the temperature of the battery 12, but if the heating load of the air conditioner is zero, the coolant may be circulated only through the water-water heat exchanger 24, and if there is no need to increase the temperature of the battery 12, the coolant may be circulated only through the heater core 44. The same applies to the second and third modes described below.

[0038] [Second mode (engine exhaust heat and heater heating)] 3 , in the engine coolant circuit 30, the battery coolant circuit 20 and / or the heater core 44 may be heated by the exhaust heat of the engine 11 and the heating of the heater 45 (hereinafter referred to as the second mode). In the second mode, the flow shutting valve 42 is opened, the three-way adjustment valve 43 is adjusted based on the heating load of the air conditioner and the battery temperature, the pump 46 is driven, and the three-way switching valve 47 is switched to communicate between the heater path 34 and the engine bypass path 36. In the second mode, the coolant is heated by the exhaust heat of the engine 11, heated by the heater 45, heats the heater core 44 and the water-water heat exchanger 24, and returns to the engine 11 via the heater bypass path 35 or returns to the heater path 34.

[0039] [Third mode (heater heating only)] 4, in the engine coolant circuit 30, the battery coolant circuit 20 and the heater core 44 may be heated only by heating from the heater 45 (hereinafter referred to as the third mode). In the third mode, the flow shutting valve 42 is closed, the three-way adjustment valve 43 is adjusted based on the heating load of the air conditioner and the battery temperature, the pump 46 is driven, and the three-way switching valve 47 is switched to communicate between the heater path 34 and the engine bypass path 36. In the third mode, the coolant is heated by the heater 45, heats the heater core 44 and / or the water-water heat exchanger 24, and returns to the heater path 34.

[0040] [Control unit (ECU)] The configuration of the ECU 50 as a control unit will be described with reference to FIGS.

[0041] During rapid charging of the battery 12, the ECU 50 executes battery temperature increase control to increase the temperature of the battery 12 by using exhaust heat from the engine 11 and / or heating by the heater 45. As will be described in detail later, the ECU 50 can efficiently increase the temperature of the battery 12 by heating by the heater 45 after heating by the exhaust heat from the engine 11.

[0042] As shown in Figures 1 and 5, the ECU 50 is connected to the above-mentioned pump 22, flow shutting valve 42, three-way adjustment valve 43, heater 45, pump 46, three-way switching valve 47, battery temperature sensor 61, engine coolant temperature sensor 62, battery voltage sensor 63, and battery current sensor 64, each of which will be described in detail later.

[0043] The battery temperature sensor 61 detects the temperature of the battery 12. The battery temperature sensor 61 is provided near the battery 12. The engine coolant temperature sensor 62 detects the temperature of the engine coolant in the engine coolant circuit 30. The engine coolant temperature sensor 62 is provided, for example, downstream of the engine 11 in the engine cooling path 31. The battery voltage sensor 63 detects the voltage of the battery 12. The battery current sensor 64 detects the current related to charging and discharging of the battery 12.

[0044] The ECU 50 has a CPU (Central Processing Unit) which is an arithmetic processing unit, and memory units such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and performs signal processing according to a program pre-stored in the ROM while utilizing the temporary storage function of the RAM.

[0045] 5, the ECU 50 has a quick charge determination unit 51, a battery temperature determination unit 52, a first engine coolant temperature determination unit 53, an engine waste heat utilization unit 54, a second engine coolant temperature determination unit 55, and a heater utilization unit 56, each of which will be described in detail below. The quick charge determination unit 51, the battery temperature determination unit 52, the first engine coolant temperature determination unit 53, the engine waste heat utilization unit 54, the second engine coolant temperature determination unit 55, and the heater utilization unit 56 are realized by the CPU executing programs stored in the ROM or RAM.

[0046] The quick charge determination unit 51 determines whether or not the charge is quick charge based on the current and voltage during charging of the battery 12 detected by the above-mentioned battery voltage sensor 63 and battery current sensor 64. If separate connectors are used for quick charge and normal charge, it may be determined whether or not the charge is quick charge based on the connector (charging circuit) used.

[0047] The battery temperature determination unit 52 determines whether the temperature of the battery 12 detected by the above-described battery temperature sensor 61 is equal to or higher than a predetermined temperature. The predetermined temperature is preferably determined based on the temperature at which the battery characteristics, such as the discharge characteristics, deteriorate.

[0048] The first engine coolant temperature determination unit 53 determines whether the temperature of the engine coolant detected by the engine coolant temperature sensor 62 described above is higher than the temperature of the battery 12 or not.

[0049] The engine waste heat utilization unit 54 sets the engine coolant circuit 30 to the first mode described above, and heats the battery 12 to an appropriate temperature using only the waste heat from the engine 11. Specifically, the engine waste heat utilization unit 54 opens the flow shutting valve 42, adjusts the three-way adjustment valve 43 based on the heating load of the air conditioner and the battery temperature, stops the pump 46, and switches the three-way switching valve 47 to connect the heater path 34 and the engine cooling path 31.

[0050] According to the engine waste heat utilization unit 54, when the temperature of the engine coolant is higher than the temperature of the battery 12, the heater 45 is not operated, and the battery 12 is first heated to an appropriate temperature using only the waste heat from the engine 11, thereby suppressing an increase in power consumption due to operation of the heater 45. This allows the temperature of the battery 12 to be raised efficiently.

[0051] The second engine coolant temperature determination unit 55 determines whether the difference between the temperature of the engine coolant and the temperature of the battery 12 is equal to or less than a predetermined value. In other words, the second engine coolant temperature determination unit 55 determines whether the state in which the engine coolant is not heated and the battery 12 is heated to an appropriate temperature by the residual heat of the engine coolant has ended because the engine 11 is stopped.

[0052] The heater utilization unit 56 sets the engine coolant circuit 30 to the second mode described above, and heats the battery 12 to an appropriate temperature using the exhaust heat of the engine 11 and the heater 45. Specifically, the heater utilization unit 56 opens the flow shutting valve 42, adjusts the three-way adjustment valve 43 based on the heating load of the air conditioner and the battery temperature, drives the pump 46, and switches the three-way switching valve 47 to connect the heater path 34 to the engine bypass path 36.

[0053] The heater utilization unit 56 operates the heater 45 after the battery 12 has been heated to an appropriate temperature by the residual heat of the engine coolant, thereby suppressing an increase in power consumption due to the operation of the heater 45. This allows the temperature of the battery 12 to be raised efficiently.

[0054] [Battery temperature rise control] The flow of the battery temperature increase control will be described with reference to FIG.

[0055] The battery warming control heats the battery 12 to an appropriate temperature by the battery warming system 10 according to the following procedure and based on the functions of the ECU 50 described above. In step S11, the quick charge determination unit 51 determines whether the charge is a quick charge based on the current and voltage of the battery 12 during charging detected by the battery voltage sensor 63 and the battery current sensor 64. If quick charging is in progress, the process proceeds to step S12.

[0056] In step S12, the battery temperature determination unit 52 determines whether or not the battery temperature detected by the battery temperature sensor 61 is equal to or higher than a predetermined temperature. If the battery temperature is equal to or higher than the predetermined temperature, the process proceeds to step S13.

[0057] In step S13, the first engine coolant temperature determination unit 53 determines whether the temperature of the engine coolant detected by the engine coolant temperature sensor 62 is higher than the temperature of the battery 12. If the temperature of the engine coolant is higher than the temperature of the battery 12, the process proceeds to step S14. On the other hand, if the temperature of the engine coolant is equal to or lower than the temperature of the battery 12, the process proceeds to step S16.

[0058] In step S14, the engine waste heat utilization unit 54 sets the engine coolant circuit 30 to the first mode described above, and the battery 12 is heated to an appropriate temperature using only the waste heat from the engine 11.

[0059] In step S15, the second engine coolant temperature determination unit 55 determines whether or not the difference between the temperature of the engine coolant and the temperature of the battery 12 is equal to or less than a predetermined value. If the difference between the temperature of the engine coolant and the temperature of the battery 12 is equal to or less than the predetermined temperature, the process proceeds to step S16.

[0060] In step S16, the heater utilization unit 56 sets the engine coolant circuit 30 to the second mode described above, and the battery 12 is heated to an appropriate temperature by the exhaust heat of the engine 11 and the heater 45.

[0061] It should be noted that the present invention is not limited to the above-described embodiment and its modifications, and various changes and modifications are possible within the scope of the claims of this application. [Explanation of symbols]

[0062] 10 Battery heating system, 11 Engine, 12 Battery, 13 Radiator, 20 Battery coolant circuit, 21 Battery heat exchanger, 22 Pump, 23 Chiller, 24 Water-water heat exchanger, 30 Engine coolant circuit, 31 Engine cooling path, 32 Battery heating path (first path), 33 Heater core path (second path), 34 Heater path (third path), 35 Heater bypass path (bypass path), 36 Engine bypass path, 41 Thermostat, 42 Flow shutting valve, 43 Three-way adjustment valve, 44 Heater core, 45 Heater, 46 Pump, 47 Three-way switching valve, 50 ECU (control unit), 51 Rapid charging determination unit, 52 Battery temperature determination unit, 53 First engine coolant temperature determination unit, 54 Engine waste heat utilization unit, 55 Second engine coolant temperature determination unit, 56 Heater utilization section, 61 battery temperature sensor, 62 engine coolant temperature sensor, 63 battery voltage sensor, 64 battery current sensor

Claims

1. A battery warming system for warming a battery mounted on a vehicle, a battery coolant circuit for cooling or heating the battery to an appropriate temperature; an engine coolant circuit for cooling an engine, the engine coolant circuit having a first path for heating the battery coolant circuit, a second path for heating air to be blown into the vehicle compartment, and a third path heated by a heater; Equipped with the first path and the second path are connected in parallel, When the engine is stopped and the water temperature of the engine coolant circuit is higher than the temperature of the battery, the battery coolant circuit is heated only by exhaust heat from the engine, and thereafter, when the difference between the water temperature of the engine coolant circuit and the temperature of the battery is equal to or lower than a predetermined temperature, the battery coolant circuit is heated by heating using the heater. Battery heating system.

2. The battery warming system according to claim 1, the third path is connected in series with the first path and the second path; a bypass path that bypasses the third path is provided; Battery heating system.

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