Vehicle battery heating system

Abstract

To provide a battery temperature raising system for a vehicle which system can shorten charge time of a battery.SOLUTION: A battery temperature raising system 10 raises temperature of a battery 6 installed on a vehicle 5, and comprises: a first circuit 20 which heats up air blowing into a cabin 8 at heating operation of an air conditioner 7 circulating water heated up by an electric heater 21; and a second circuit 30 which can perform heat exchange with the first circuit 20 and can heat up the battery 6 by circulating the water heated up by the first circuit 20. In the case that a battery temperature Tb is lower than a prescribed temperature Tb1 and the air conditioner 7 is executing heating operation when a battery residual amount SOC is less than a first prescribed amount SOC1, the battery temperature raising system raises the battery temperature Tb by heating up the battery 6 by the second circuit 30.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle battery temperature increase system for increasing the temperature of a battery mounted on a vehicle.

Background Art

[0002] When charging (especially rapid charging) a battery mounted on a vehicle at a low temperature, the charging amount of the battery may be limited because the battery temperature is low. Conventionally, in such a case, the battery temperature has been increased by a battery temperature increase system so that the charging amount of the battery is not limited. For example, Patent Document 1 discloses a battery temperature increase system that circulates water heated by an internal combustion engine, a heat accumulator, or an electric heater to heat the battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when starting to increase the temperature of the battery by the above battery temperature increase system after the start of charging, since the heat capacity of the battery is large, the charging amount of the battery is limited until the battery reaches the target temperature (the temperature at which the limitation of the charging amount of the battery is released), so the charging time may become long.

[0005] Therefore, an object of the present invention is to provide a vehicle battery temperature increase system that can shorten the charging time of the battery.

Means for Solving the Problems

[0006] The vehicle battery temperature increasing system according to the present invention is a vehicle battery temperature increasing system for increasing the temperature of a battery mounted on a vehicle, comprising: a first circuit that circulates water heated by a heating unit to heat air blown into a vehicle interior during a heating operation of an air conditioner; and a second circuit that is heat-exchangeable with the first circuit and circulates water heated by the first circuit to heat the battery. When the remaining battery level is less than a first predetermined amount, if the battery temperature is lower than a predetermined temperature and the air conditioner is in a heating operation, the battery is heated by the second circuit to increase the temperature of the battery.

[0007] With the above configuration, when the remaining battery level is less than a first predetermined amount, it is predicted that the battery will be charged soon. Therefore, when the battery temperature is lower than a predetermined temperature and the air conditioner is in a heating operation, the battery can be preheated, and then the charging time when charging the battery can be shortened.

[0008] In the vehicle battery temperature increasing system according to the present invention, when the remaining battery level is less than a second predetermined amount (less than the first predetermined amount), if the battery temperature is lower than a predetermined temperature and the air conditioner is in a heating operation, it is preferable to increase the output of the heating unit and heat the battery by the second circuit to increase the temperature of the battery.

[0009] With the above configuration, when the remaining battery level is less than a second predetermined amount (less than the first predetermined amount), it is predicted that the battery will be charged soon. Therefore, when the battery temperature is lower than a predetermined temperature and the air conditioner is in a heating operation, the output of the heating unit is increased to quickly preheat the battery in advance, and then the charging time when charging the battery can be shortened.

Advantages of the Invention

[0010] According to the vehicle battery temperature increasing system of the present invention, the battery can be preheated in advance, and the subsequent battery charging time can be shortened.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0012] Hereinafter, an example of an embodiment of the present invention will be described in detail. In the following description, specific shapes, materials, directions, numerical values, etc. are examples for facilitating the understanding of the present invention, and can be appropriately changed according to applications, purposes, specifications, etc.

[0013] The battery temperature increase system 10 is a system for increasing the temperature of the battery 6 mounted on the vehicle 5. According to the battery temperature increase system 10, although details will be described later, when the state of charge SOC of the battery 6 is low, since it is predicted that the battery 6 will be charged soon, the battery temperature Tb is low, and when the air conditioner 7 is in the heating operation, the battery 6 can be preheated to shorten the subsequent charging time of the battery 6.

[0014] "Vehicle" The vehicle 5 according to the embodiment will be described with reference to FIG. 1.

[0015] The vehicle 5 of the present embodiment is a four-wheel electric vehicle, and travels by an electric motor (not shown) powered by the battery 6. However, the vehicle 5 is not limited to an electric vehicle, and may be, for example, a hybrid vehicle. The vehicle 5 has a battery 6, an air conditioner 7, and a battery temperature increase system 10, the details of which will be described later. Further, the vehicle 5 has an outside air temperature sensor 51 for detecting the outside air temperature To, a battery temperature sensor 52 for detecting the battery temperature Tb, and a vehicle speed sensor 53 for detecting the vehicle speed V of the vehicle 5.

[0016] The battery 6 is rechargeable and supplies power to the electric motor for driving. When charging is performed in a state where the battery temperature Tb is low, the charging efficiency decreases. A decrease in the charging efficiency means that the charging time increases and the amount of charge decreases. The charging or discharging of the battery 6 is controlled by a battery ECU (not shown).

[0017] The air conditioner 7 conditions the interior of the vehicle compartment 8 by performing cooling operation and heating operation. When the air conditioner 7 performs heating operation, the air blown into the vehicle compartment 8 is heated by the water circulating in the first circuit 20 described later. The air conditioner 7 is controlled for cooling or heating operation by an air conditioner ECU (not shown).

[0018] "Battery Temperature Rise System" With reference to FIG. 2, a battery temperature rise system 10 which is an example of an embodiment will be described.

[0019] The battery temperature rise system 10 is a system that raises the temperature of the battery 6 as described above. The battery temperature rise system 10 includes a first circuit 20, a second circuit 30, and a control device (hereinafter, ECU (Electronic Control Unit) 40), the details of which will be described later.

[0020] The first circuit 20 includes an electric heater 21 as a heating unit, a pump 22 that circulates water as a heat medium, a heater core 23 that heats the air blown into the vehicle compartment 8 during heating of the air conditioner 7, and a heat exchanger 24 that exchanges heat with the water circulating in the second circuit 30. Note that the first circuit 20 may have a flow control valve and be configured to be able to control the flow rate of the circulating water. Also, in the first circuit 20, not only a configuration in which the circulating water is heated by the electric heater 21, but also a configuration in which a heat exchanger is provided in the first circuit 20 and the heat exchanger is heated by a heat pump cycle may be employed.

[0021] With the above configuration, the heat of the electric heater 21 is transmitted to the heater core 23 using the circulating water as a medium, heating the air blown into the vehicle compartment 8 during heating of the air conditioner 7, and the heat of the electric heater 21 is transmitted to the second circuit 30 via the heat exchanger 24.

[0022] The second circuit 30 includes the heat exchanger 24 described above, a pump 32 that circulates water as a heat medium, and a battery heater 33 that passes the circulating water around the battery 6 to heat the battery 6. The second circuit 30 may have a flow control valve and be configured to control the flow rate of the circulating water. With the above configuration, the heat of the electric heater 21 in the first circuit 20 is transmitted to the battery heater 33 via the second circuit 30 using the circulating water as a medium, and the battery 6 can be heated to raise the temperature of the battery 6.

[0023] The ECU 40 will be described with reference to FIG. 3.

[0024] The ECU 40 executes battery temperature increase control, the details of which will be described later, in the battery temperature increase system 10. The ECU 40 is a computer having a processor 41 having a CPU that performs information processing therein, and a memory 42 that stores software, programs, or data executed by the processor 41 (see FIG. 2).

[0025] As shown in FIG. 3, the ECU 40 is connected to the outside air temperature sensor 51, the battery temperature sensor 52, the vehicle speed sensor 53, an air conditioning ECU (not shown), and a battery ECU (not shown), which are described above. The ECU 40 can acquire the outside air temperature Tо, the battery temperature Tb, that the vehicle 5 is running, that the air conditioning device 7 is in a heating operation state, and the state of charge SOC of the battery 6 from the sensors and the units.

[0026] The ECU 40 has a first battery temperature increase unit 43 and a second battery temperature increase unit 44, the details of which will be described later. The first battery temperature increase unit 43 and the second battery temperature increase unit 44 are realized by the processor 41 executing a program stored in the memory 42.

[0027] When the vehicle 5 is running and the remaining battery level SOC is less than the first predetermined amount SOC1, if the battery temperature Tb is lower than the predetermined temperature Tb1 and the air conditioner 7 is in the heating operation, the pump 32 of the second circuit 30 is driven to circulate the water in the second circuit 30. Since the air conditioner 7 is in the heating operation, the pump 22 of the first circuit 20 is driven and the circulating water in the first circuit 20 is circulating.

[0028] In addition, when the air conditioner 7 is not in the heating operation, it is unlikely that the battery temperature Tb will be lower than the predetermined temperature Tb1, so there is no need to raise the temperature of the battery 6.

[0029] Thereby, the heat of the electric heater 21 is transmitted to the heat exchanger 24 by the water circulating in the first circuit 20, and the heat transmitted to the heat exchanger 24 is transmitted to the battery heater 33 by the water circulating in the second circuit 30, and the battery 6 is heated.

[0030] That is, when the remaining battery level SOC is less than the first predetermined amount SOC1, it is predicted that the battery 6 will be charged in the near future. Therefore, when the battery temperature Tb is lower than the predetermined temperature Tb1 and the air conditioner 7 is in the heating operation, the temperature of the battery 6 can be raised in advance, and the subsequent charging time of the battery 6 can be shortened.

[0031] When the vehicle 5 is running and the remaining battery level SOC is less than the second predetermined amount SOC2 (less than the first predetermined amount SOC1), if the battery temperature Tb is lower than the predetermined temperature Tb1 and the air conditioner 7 is in the heating operation, the output of the electric heater 21 is increased, and the pump 32 of the second circuit 30 is driven to circulate the water in the second circuit 30. As described above, since the air conditioner 7 is in the heating operation, the pump 22 of the first circuit 20 is driven and the circulating water in the first circuit 20 is circulating.

[0032] By increasing the output of the electric heater 21, the heat of the electric heater 21 is transferred to the heat exchanger 24 by the water circulating in the first circuit 20, and the heat transferred to the heat exchanger 24 is transferred to the battery heater 33 by the water circulating in the second circuit 30, and the battery 6 is heated significantly.

[0033] Here, to increase the output of the electric heater 21, it is preferable to increase the target water temperature TWО of the first circuit 20. At this time, a temperature sensor may be provided in the first circuit 20, and the output of the electric heater 21 may be increased by feedback control while detecting the water temperature of the circulating water in the first circuit 20.

[0034] That is, when the state of charge SOC of the battery 6 is extremely low, since it is predicted that the battery 6 will be charged soon, when the battery temperature Tb is low and the air conditioner 7 is in the heating operation, the output of the electric heater 21 can be increased to quickly raise the temperature of the battery 6 in advance, and then the charging time when charging the battery 6 can be shortened.

[0035] The flow of battery temperature increase control by the control device 40 will be described with reference to FIG. 4.

[0036] In step S11, the processor 41 checks whether the vehicle 5 is running by the vehicle speed sensor 53. Specifically, if the vehicle speed V is equal to or higher than a predetermined speed V1, it is considered that the vehicle is running. If the vehicle 5 is running, the process proceeds to step S12.

[0037] In step S12, the processor 41 checks whether the outside air temperature Tо is lower than a predetermined temperature Tо1 by the outside air temperature sensor 51. If the outside air temperature Tо is lower than the predetermined temperature Tо1, the process proceeds to step S13.

[0038] In step S13, the processor 41 checks whether the battery temperature Tb is lower than a predetermined temperature Tb1 by the battery temperature sensor 52. If the battery temperature Tb is lower than the predetermined temperature Tb1, the process proceeds to step S14.

[0039] In step S14, the processor 41 checks whether the air conditioner 7 is in a heating operation state by the air conditioner ECU. If the air conditioner 7 is in a heating operation state, the process proceeds to step S15.

[0040] In step S15, the processor 41 checks whether the battery remaining amount SOC is less than a first predetermined amount SOC1 by the battery ECU. If the battery remaining amount SOC is less than the first predetermined amount SOC1, the process proceeds to step S16.

[0041] In step S16, the processor 41 checks whether the battery remaining amount SOC is less than a second predetermined amount SOC2 by the battery ECU. If the battery remaining amount SOC is greater than or equal to the second predetermined amount SOC2, the process proceeds to step S17. If the battery remaining amount SOC is less than the second predetermined amount SOC2, the process proceeds to step S18.

[0042] In step S17, the processor 41 drives the pump 32 of the second circuit 30 to circulate the water in the second circuit 30. As a result, the heat of the electric heater 21 is transmitted to the heat exchanger 24 by the water circulating in the first circuit 20, and the heat transmitted to the heat exchanger 24 is transmitted to the battery heater 33 by the water circulating in the second circuit 30, and the battery 6 is heated.

[0043] As a result, when the battery remaining amount SOC is low, since it is predicted that the battery 6 will be charged soon, if the battery temperature Tb is lower than a predetermined temperature Tb1 and the air conditioner 7 is in a heating operation state, the battery 6 can be preheated to shorten the subsequent charging time of the battery 6.

[0044] In step S18, the processor 41 increases the output of the electric heater 21 and drives the pump 32 of the second circuit 30 to circulate the water in the second circuit 30. The output of the electric heater 21 is increased, the heat of the electric heater 21 is transmitted to the heat exchanger 24 by the water circulating in the first circuit 20, and the heat transmitted to the heat exchanger 24 is transmitted to the battery heater 33 by the water circulating in the second circuit 30, and the battery 6 is heated.

[0045] As a result, when the remaining battery level SOC of the battery 6 is extremely low, a situation where the battery 6 will be charged soon is predicted. Therefore, when the battery temperature Tb is low and the air conditioner 7 is operating in the heating mode, the output of the electric heater 21 can be increased to rapidly raise the temperature of the battery 6 in advance, and then the charging time when charging the battery 6 can be shortened.

[0046] Note that the present invention is not limited to the above-described embodiments and their modified examples, and it goes without saying that various changes and improvements can be made within the scope of the matters described in the claims of the present application.

Explanation of Reference Numerals

[0047] 5 Vehicle, 6 Battery, 7 Air conditioner, 8 Interior of the vehicle, 10 Battery temperature raising system, 20 First heating circuit, 21 Electric heater (heating unit), 22 Pump, 23 Heater core, 24 Heat exchanger, 30 Second heating circuit, 31 Pump, 32 Battery heater, 40 Control device (ECU), 41 Processor, 42 Memory, 43 First battery temperature raising unit, 44 Second battery temperature raising unit, 51 Outside air temperature sensor, 52 Battery temperature sensor, 53 Vehicle speed sensor

Claims

【Claim 1】 A vehicle battery warming system for warming a battery mounted on a vehicle, comprising: a first circuit that circulates water heated by a heating unit and heats air blown into a vehicle interior during heating operation of an air conditioner; a second circuit that is heat-exchangeable with the first circuit and circulates water heated by the first circuit to heat the battery; wherein when the remaining amount of the battery is less than a first predetermined amount, the battery temperature is lower than a predetermined temperature, and the air conditioner is in a heating operation, the battery is warmed by heating the battery with the second circuit; when the remaining amount of the battery is less than a second predetermined amount that is less than the first predetermined amount, the battery temperature is lower than the predetermined temperature, and the air conditioner is in a heating operation, the output of the heating unit is increased and the battery is warmed by heating the battery with the second circuit; a vehicle battery warming system.

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