Battery temperature control method and battery temperature regulation system

Abstract

Provided is a battery temperature control method for controlling a battery temperature regulation system comprising: an air conditioning case that accommodates a heat exchanger, a heating device, and a regulator that regulates the mixing ratio of air that has passed through the heat exchanger and air that has passed through the heating device; a first air passage for supplying outside air introduced into the air conditioning case to a battery case; a second air passage for supplying the air that has passed through the heat exchanger to the battery case; a third air passage for supplying the air that has passed through the heating device to the battery case; a fourth air passage for supplying the air that has passed through the regulator to the battery case; a fifth air passage for supplying air in a vehicle cabin to the battery case; a case inner passage that is provided in the battery case and that is a battery temperature regulation passage; and a sixth air passage for recirculating air that has passed through the case inner passage in the battery case, wherein a controller regulates the amount of air supplied to the battery case from each air passage from the first air passage to the fifth air passage, according to the temperature of the battery.

Description

Battery temperature control method and battery temperature control system

[0001] The present invention relates to a battery temperature control method and a battery temperature adjustment system.

[0002] The performance and lifespan of a battery are affected by the temperature during charging and discharging. Therefore, it is desirable to control the temperature of the battery so that it remains within an appropriate temperature range. Battery temperature control can be achieved using a water-cooled system that uses a refrigerant such as cooling water, or an air-cooled system that uses air such as outside air. Air-cooled systems are advantageous in terms of structural simplicity, weight, cost, and other factors. JP 2021-197221 A discloses an air-cooled cooling mechanism for an in-vehicle all-solid-state battery, which includes a housing that houses the all-solid-state battery, an intake mechanism that sends gas into the housing, and an exhaust mechanism that exhausts the gas from the housing. This cooling mechanism is configured to suppress temperature increases in the all-solid-state battery by operating the exhaust mechanism so that the exhaust speed is greater than the intake speed of the intake mechanism, depending on the temperature of the all-solid-state battery.

[0003] According to the above-mentioned document, the gas sent into the housing by the intake mechanism is air, inert gas, cooled gas, etc., and the intake mechanism is, for example, an intake fan. However, if outside air or air from inside the vehicle cabin is used, the cooling capacity may be insufficient depending on the temperature of the air. Furthermore, if air cooled by an air conditioning system is used, the power consumption of the air conditioning system may increase.

[0004] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a battery temperature control method and a battery temperature regulation system that can keep the battery temperature within an optimum temperature range while suppressing an increase in the power consumption of an air conditioning system.

[0005] According to one aspect of the present invention, there is provided a battery temperature control method for controlling a battery temperature control system including an air conditioning case that houses a heat exchanger, a heating device, and a regulator that adjusts the mixture ratio of air that has passed through the heat exchanger and air that has passed through the heating device, a first air passage that supplies outside air introduced into the air conditioning case from the air conditioning case to a battery case, a second air passage that supplies air that has passed through the heat exchanger from the air conditioning case to the battery case, a third air passage that supplies air that has passed through the heating device from the air conditioning case to the battery case, a fourth air passage that supplies air that has passed through the regulator from the air conditioning case to the battery case, a fifth air passage that supplies air from inside the vehicle cabin to the battery case, and an internal-case passage for controlling the battery temperature, wherein a controller adjusts the amount of air supplied to the battery case from each of the first to fifth air passages in accordance with the temperature of the battery.

[0006] FIG. 1 is a schematic diagram of a battery temperature control system. FIG. 2 is a cross-sectional view showing the schematic configuration of a battery case. FIG. 3 is a diagram showing the air flow in a cooling mode. FIG. 4 is a diagram showing the air flow in a heating mode. FIG. 5 is a diagram showing the air flow in a rapid heating mode. FIG. 6 is a diagram showing the air flow in a rapid cooling mode. FIG. 7 is a flowchart showing a control routine for battery temperature control. FIG. 8 is a diagram showing the relationship between the flow rate of temperature control air and the heat transfer coefficient, temperature, and required energy. FIG. 9 is a schematic diagram of a battery temperature control system according to a modified example. FIG. 10 is a schematic diagram of a rotary valve.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0008] [System Configuration] FIG. 1 is a schematic configuration diagram of a battery temperature adjustment system 1 according to an embodiment of the present invention.

[0009] The battery temperature control system 1 includes an air conditioning system 5, a battery case 9 that houses a battery 53, a battery pump 10 that supplies air to the battery case 9, and a controller 50. The battery temperature control system 1 according to this embodiment is mounted on an electrically powered vehicle such as an electric vehicle (BEV) or a hybrid vehicle (HEV). The battery 53 is, for example, an all-solid-state battery.

[0010] The air conditioning system 5 includes a heat exchanger 3 that cools the air passing through, a heating device 2 that heats the air passing through, a regulator 4 that adjusts the mixing ratio of the air that has passed through the heat exchanger 3 and the air that has passed through the heating device 2 according to a target temperature, an inside / outside switch 6 that switches between outside air introduction mode and inside air circulation mode, an air conditioning pump 7, and an air conditioning case 5A that houses these.

[0011] The inside / outside switch 6 is connected to the outside air introduction passage 20 and an inside air circulation passage 26 that circulates air in the passenger compartment 8. The inside / outside switch 6 has the function of connecting the outside air introduction passage 20 in the outside air introduction mode and connecting the inside air circulation passage 26 in the inside air circulation mode.

[0012] The air conditioning system 5 also includes a pre-heating passage 21 that connects the internal / external switch 6 and the heating device 2, a pre-cooling passage 22 that connects the internal / external switch 6 and the heat exchanger 3, a post-heating passage 23 that connects the heating device 2 and the regulator 4, and a post-cooling passage 24 that connects the heat exchanger 3 and the regulator 4. The air conditioning system 5 further includes a post-mixing passage 25 that connects the regulator 4 and the passenger compartment 8. A pump 7 is installed in the post-mixing passage 25 to supply air from the air conditioning case 5A to the passenger compartment 8. In this embodiment, the air flowing through the post-mixing passage 25 is also referred to as room temperature air.

[0013] The controller 50 controls the air conditioning system 5 in a general manner, such as switching between outside air introduction mode and inside air circulation mode, and adjusting the temperature and air volume of the room air according to the set temperature, as well as controlling the battery temperature, which will be described later.

[0014] The controller 50 is composed of a microcomputer equipped with a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface).

[0015] The controller 50 may be configured with a plurality of microcomputers. For example, the controller 50 may be configured with a control module that calculates the temperature and air volume of the air supplied to the passenger compartment 8 and the like and the required load capacity in the battery temperature control described later, an air conditioning control module that controls the air conditioning pump 7, the battery pump 10, and various valves described later, and a battery control module that manages the temperature of the battery 53, etc.

[0016] The battery temperature adjustment system 1 also includes first to sixth air passages 31 to 36 and an internal case passage 51, which will be described later.

[0017] The first air passage 31 is a passage that supplies outside air introduced into the air conditioning case 5A to the battery case 9. Specifically, the first air passage 31 is a passage that branches off from the outside air introduction passage 20 upstream of the inside / outside switch 6 and is connected to the battery case 9. A first valve 41 that opens and closes the flow path is disposed in the first air passage 31.

[0018] The second air passage 32 is a passage that supplies air that has been cooled and dehumidified by passing through the heat exchanger 3 (hereinafter also referred to as low-temperature air) from the air conditioning case 5A to the battery case 9. Specifically, it is a passage that branches off from the post-cooling passage 24 and is connected to the battery case 9. A second valve 42 that opens and closes the flow path is provided in the second air passage 32.

[0019] The third air passage 33 is a passage that supplies air heated by passing through the heating device 2 (hereinafter also referred to as high-temperature air) from the air conditioning case 5A to the battery case 9. Specifically, it is a passage that branches off from the post-heating passage 23 and is connected to the battery case 9. A third valve 43 that opens and closes the flow path is interposed in the third air passage 33.

[0020] The fourth air passage 34 is a passage that supplies room temperature air that has passed through the regulator 4 from the air conditioning case 5A to the battery case 9. Specifically, it is a passage that branches off from the post-mixing passage 25 and is connected to the battery case 9. A fourth valve 44 that opens and closes the flow path is provided in the fourth air passage 34.

[0021] The fifth air passage 35 is a passage that supplies air from within the vehicle interior 8 to the battery case 9. Specifically, it is a passage that branches off from the first exhaust passage 27 that exhausts air from within the vehicle interior 8 to the outside of the vehicle and is connected to the battery case 9. A fifth valve 45 that opens and closes the flow path is provided in the fifth air passage 35.

[0022] The sixth air passage 36 is a passage that recirculates the air discharged from the battery case 9 back into the battery case 9. Specifically, the sixth air passage 36 branches off from the second discharge passage 28 and is connected to the battery case 9. A sixth valve 46 that opens and closes the flow path is provided in the sixth air passage 36.

[0023] The case internal passage 51 is a passage for regulating the battery temperature provided inside the battery case 9. Here, the case internal passage 51 will be described with reference to FIG.

[0024] 2 is a cross-sectional view showing a schematic configuration of the battery case 9. In this figure, the left-right direction on the paper is the x-direction, and the up-down direction on the paper is the y-direction.

[0025] The battery case 9 accommodates a plurality of batteries 53. The batteries 53 are arranged in the x direction with their longitudinal directions parallel to one another and with a predetermined gap between adjacent batteries 53. The spaces between adjacent batteries 53 are referred to as spaces 51C. Although not shown, the batteries 53 are electrically connected in series or parallel. Furthermore, spaces 51A and 51B are provided inside the battery case 9 on both sides of the batteries 53 in the y direction. The space 51A above the batteries 53 in the y direction, the spaces 51C on both sides of each battery 53, and the space 51B below the batteries 53 in the y direction are interconnected, and these form an internal case passage 51.

[0026] An inlet opening 9A that connects the space 51A to the outside of the case and an outlet opening 9B that connects the space 51B to the outside of the case are provided at both ends of the battery case 9 in the x direction. One end of an inlet passage 38, the other end of which is connected to the outlet of the battery pump 10, is connected to the inlet opening 9A. A second exhaust passage 28 that exhausts air inside the battery case 9 to the outside is connected to the outlet opening 9B.

[0027] The air that flows into the battery case 9 from the inlet passage 38 flows in the x direction through the space 51A and branches into each space 51C. The air that passes through each space 51C then joins in the space 51B, flows in the x direction, and is discharged from the second discharge passage 28.

[0028] In addition, a battery temperature sensor 63 is provided in each battery 53, an inlet temperature sensor 60 is provided in the inlet opening 9A, and an outlet temperature sensor 61 is provided in the outlet opening 9B, and the detection signals of each sensor 60, 61, 62 are sent to the controller 50.

[0029] A heat insulating material 52 is provided on the inner wall or outer wall of the battery case 9 .

[0030] Returning to the explanation of Figure 1, the battery temperature regulation system 1 further includes a seventh air passage 37. The seventh air passage 37 is a passage that supplies air discharged from the battery case 9 to the regulator 4. Specifically, the seventh air passage 37 branches off from the sixth air passage 36 and is connected to the regulator 4.

[0031] [Battery Temperature Control] Next, we will explain the battery temperature control performed by the battery temperature control system 1. The controller 50 performs battery temperature control in each of the following situations so that the temperature of the battery 53 (hereinafter also referred to as battery temperature) falls within an appropriate temperature range determined from the viewpoints of performance, durability, etc.

[0032] (1) Heat retention mode When the vehicle is stopped after arriving at a destination or after returning home, or when the battery temperature is within the optimum temperature range while the vehicle is running, the controller 50 stops the battery pump 10 and closes each of the valves 41-46 to maintain the temperature inside the battery case 9. Because the battery case 9 is surrounded by a heat insulating material 52, the above control suppresses temperature changes.

[0033] (2) Cooling Mode If the battery temperature exceeds or is likely to exceed the upper limit of the optimum temperature range while the vehicle is running, the controller 50 operates the battery pump 10 and opens or closes each of the valves 41-46 to lower the temperature of the battery 53. Specifically, by opening valves 41, 42, 44, 45, and 46 and closing valve 43, a mixture of outside air, low-temperature air, room temperature air, and battery exhaust air is used as temperature-regulating air (see the bold arrows in FIG. 3). In the following description, the air supplied to the battery case 9 is also referred to as temperature-regulating air.

[0034] The controller 50 sets a required load capacity for the battery temperature control system according to the battery temperature, and based on this, sets a target temperature of the temperature control air (hereinafter also referred to as the target temperature control air temperature). The relationship between the required load capacity and the target temperature control air temperature will be described later.

[0035] Then, based on the temperatures of the outside air, the low temperature air, and the room temperature air, the controller 50 sets the mixing ratio of the outside air, the low temperature air, the room temperature air, and the battery discharge air so that the temperature of the temperature control air becomes the target temperature control air temperature, and controls the opening degree of each of the valves 41, 42, 44, 45, and 46 accordingly.

[0036] The reason why the valve 46 is opened and the air heated by the battery 53 inside the battery case 9, i.e., the battery exhaust air, is supplied to the regulator 4 is to accommodate the dehumidifying and heating mode of the air conditioning system 5. During dehumidifying and heating, the air dehumidified by cooling using the heat exchanger 3 is reheated using a reheating heater (not shown) or the like before being supplied to the passenger compartment 8. This results in a higher energy consumption than in normal heating without dehumidification (hereinafter also referred to as simple heating). In particular, in vehicles that use electricity for both cooling and heating, such as electric vehicles, the increased energy consumption is a problem.

[0037] However, by opening the valve 46 as described above, it becomes possible to heat the air dehumidified by the heat exchanger 3 using the battery discharge air, thereby reducing the energy required for reheating.

[0038] (3) Heating Mode If the battery temperature falls below or is likely to fall below the lower limit of the optimum temperature range while the vehicle is running, the controller 50 operates the battery pump 10 and opens the valves 41-46 to raise the temperature of the battery 53. As a result, the temperature-regulating air is a mixture of room temperature air, air discharged from the passenger compartment 8, outside air, low-temperature air, high-temperature air, and air discharged from the battery (see the bold arrows in FIG. 4). The controller 50 then sets the openings of the valves 41-46 in the same way as during cooling.

[0039] Furthermore, if the battery temperature is within the optimum temperature range while the vehicle is running, the heat retention mode may be executed to keep the battery warm, or the battery pump 10 may be operated and the valves 41-46 may be opened or closed in the same manner as in the case of increasing the temperature. However, when increasing the temperature, the temperature of the temperature-regulating air is set lower than in the temperature increase mode.

[0040] If the only purpose is to raise the temperature and maintain the temperature, there is no need to include low-temperature air in the temperature-control air. However, for example, when introducing high-temperature, high-humidity outside air, condensation may occur on the surface of the battery 53 due to the mixing of air of different temperatures or the low battery temperature. Therefore, in this embodiment, to prevent condensation, the temperature-control air includes low-temperature air that has been dehumidified by cooling in the heat exchanger 3.

[0041] The term "air discharged from the passenger compartment 8" includes not only air discharged from the passenger compartment 8 to the outside of the vehicle in the outside air introduction mode, but also air discharged from the passenger compartment 8 in the inside air recirculation mode. Because the air in the passenger compartment 8 contains water vapor from the occupants' exhalations, the humidity of the circulating air gradually increases as the inside air recirculation mode continues. Therefore, in a typical vehicle, to prevent window fogging, a certain percentage of the air is discharged to the outside of the vehicle without being recirculated, even in the inside air recirculation mode, and fresh outside air is introduced to compensate for the amount of air discharged. The temperature inside the passenger compartment 8 is often set to around 25°C, which is close to the optimum temperature of the battery 53. Therefore, in this embodiment, the air that would normally be discharged to the outside of the vehicle in a typical vehicle for the above-mentioned reasons is used for battery temperature control. This reduces the energy required for battery temperature control.

[0042] (4) Rapid Heat-Up Mode When charging the battery 53 from a low temperature, it is necessary to quickly heat the battery 53 to an appropriate temperature range. In this case, the controller 50 operates the battery pump 10 and opens the valves 41 and 43, thereby mixing high-temperature air and outside air to create temperature-regulating air (see FIG. 5). Furthermore, the controller 50 causes the battery 53 to undergo ripple discharge. This causes the temperature of the battery 53 to rise through heat exchange with the temperature-regulating air and self-heating due to ripple discharge. Note that the introduction of outside air is not essential, and it may not be necessary to introduce outside air, for example, if the outside air temperature is lower than the appropriate temperature range.

[0043] (5) Rapid Cooling Mode When the temperature of the battery 53 rises rapidly, for example, during rapid charging, the controller 50 opens the valve 42 to use low-temperature air as temperature-regulating air (see the bold arrow in FIG. 6). This allows the battery 53 to be cooled quickly. Note that if the outside air temperature is sufficiently low, outside air may be introduced in addition to the low-temperature air. This reduces the energy required for cooling in the heat exchanger 3.

[0044] Incidentally, when air of different temperatures is mixed to produce temperature-regulating air in each of the above modes, unevenness in the temperature of the temperature-regulating air may cause variations in the cooling or heating effect among the multiple batteries 53. Therefore, in this embodiment, the battery pump 10 is provided in the inlet passage 38 after the first air passage 31 to the fifth air passage 35 all join together and before the battery case 9. As a result, the temperature-regulating air is agitated by the battery pump 10 before flowing into the battery case 9, reducing temperature unevenness and suppressing variations in the cooling or heating effect.

[0045] Furthermore, when switching between the above modes, a sudden change in the temperature of the temperature-control air generates a temperature difference inside the battery case 9, which accelerates the deterioration of the battery 53. Therefore, in this embodiment, the rotation speed of the battery compressor 10 and the opening degrees of the valves 41-45 are controlled so that the difference between the detected values ​​of the inlet temperature sensor 60 and the outlet temperature sensor 61 is within a predetermined temperature difference. The predetermined temperature difference here is a temperature that can suppress the deterioration of the battery 53 and is a value determined depending on the size of the battery 53, etc. For a battery pack of a size that is typical for an electric vehicle, it is, for example, 1 to 2°C. When the temperature difference inside the battery case 9 is large, the controller 50 controls the battery compressor 10 to increase the flow rate of the temperature-control air. Increasing the flow rate of the temperature-control air increases the air flow rate inside the battery case 9, reducing the temperature difference between the spaces 51A and 51B. In addition, the variation in flow rate between the multiple spaces 51C reduces the temperature variation inside the battery case 9. This suppresses the deterioration of the battery 53.

[0046] [Control Routine] Next, a control routine for battery temperature regulation control will be described. Fig. 7 is a flowchart showing an example of the control routine executed by the controller 50. The following will describe the steps of the flowchart.

[0047] In step S100, the controller 50 determines whether or not there is a battery temperature control request. If there is a request, the controller executes the process of step S110. If there is no request, the controller determines in step S180 that battery temperature control will not be performed and ends the current routine. In this step, for example, if the battery temperature is within the optimum temperature range, it is determined that there is a battery temperature control request, and if it is outside the optimum temperature range, it is determined that there is no battery temperature control request. Note that even if the battery temperature is within the optimum temperature range, it may be determined that there is a battery temperature control request if the temperature is close to the upper or lower limit of the optimum temperature range.

[0048] In step S110, the controller 50 acquires various data. The various data include the required load capacity of the battery temperature control system 1, the required output of the air conditioning system 5, the outside air temperature, the outside air humidity, and the temperatures of the low-temperature air, high-temperature air, and room-temperature air in the air conditioning case 5A. The outside air temperature and humidity can be detected by sensors (not shown). The required output of the air conditioning system 5 is determined according to the target temperature of the air conditioning system 5. The temperatures of the low-temperature air, high-temperature air, and room-temperature air may be estimated based on the temperatures of the heating device 2 and the heat exchanger 3 set according to the target temperature and the mixing ratio set by the regulator 4, or may be detected by temperature sensors provided in each section.

[0049] The required load capacity is the amount of heat transfer (i.e., the amount of heat transfer) required to raise the battery temperature to a target temperature within the optimum temperature range, and varies depending on the battery temperature. The required load capacity in the battery temperature control system 1 according to this embodiment is, for example, 0 kW in the keep-warm mode, approximately 0 to 10 kW in the warm-up mode, approximately 0 to -2 kW in the keep-warm mode while driving, and approximately -2 to -10 kW in the cooling mode. The specific value of the required load capacity is determined according to the chemical characteristics of the battery 53 used. Therefore, when a battery 53 with different chemical characteristics is used, the magnitude relationship of the required load capacity between the modes remains the same, but the specific value of the required load capacity in each mode will be different from the above.

[0050] In step S120, the controller 50 calculates the mixture ratio and air volume of the temperature control air. The mixture ratio is determined as follows: First, a target temperature of the temperature control air for achieving the required load capacity is calculated using equation (1).

[0051]

[0052] In equation (1), Tair is the target temperature of the temperature control air, Tbatt is the battery temperature, Qreq is the required load capacity, α is the heat transfer coefficient between the battery and the temperature control air, and Area is the heat transfer area between the battery and the temperature control air.

[0053] Then, based on the operating conditions of the air conditioning system 5, i.e., the temperature of the low temperature air, the temperature of the high temperature air, the temperature of the room temperature air, and the target humidity, the ratio of air to be supplied from each air passage from the first air passage 31 to the fifth air passage 35 is determined so as to achieve the target temperature-control air temperature.

[0054] The air volume is set to a value that makes Qair as small as possible using equation (2), as will be described later.

[0055]

[0056] In equation (2), Q is the energy required to achieve the target temperature control air temperature (hereinafter also referred to as required energy), m is the mass flow rate of the temperature control air, C is the specific heat of the air, and Tam is the outside air temperature. The required energy Q is the energy used mainly to operate the air conditioning system 5 and the battery pump 10.

[0057] In equations (1) and (2), the battery 53 is regarded as a simple flat plate, and heat transfer between the battery and the temperature-regulating air is treated as forced convection heat transfer along the flat plate.

[0058] Here, a method for setting the air volume will be described with reference to FIG.

[0059] 8 is a diagram showing the results of calculations based on equations (1) and (2) of the relationship between the flow rate of the temperature control air in the battery case 9 when the battery temperature is 40°C and there is a cooling request, the target temperature control air temperature Tair to satisfy the cooling request, the energy (hereinafter also referred to as required energy) Qair to generate the target temperature control air temperature Tair, and the heat transfer coefficient α. Note that the required energy Qair results for three patterns of outside air temperatures: 35°C, 37.5°C, and 40°C.

[0060] The heat transfer coefficient α is divided into a laminar heat transfer region and a turbulent heat transfer region at the boundary of the flow velocity V1. Because the heat transfer coefficient in the laminar heat transfer region is lower than that in the turbulent heat transfer region, the target temperature control air temperature must be lower than in the turbulent heat transfer region to achieve the same cooling performance. This means that the air conditioning system 5 consumes more energy to generate low-temperature air. For this reason, the laminar heat transfer region requires more energy, Qair, than the turbulent heat transfer region.

[0061] In the turbulent heat transfer region, the higher the flow velocity, the greater the heat transfer coefficient α, but the magnitude of the required energy Qair behaves differently depending on the outside air temperature. Therefore, in this embodiment, the air volume is set so that the flow velocity within the turbulent heat transfer region minimizes the required energy Qair. This reduces the amount of energy consumed for battery temperature control. In Figure 8, the air volumes within the turbulent heat transfer region where the required energy Qair is minimized are V2 m / s when the outside air temperature is 35°C, V4 m / s when the outside air temperature is 37.5°C, and V3 m / s when the outside air temperature is 40°C. Note that the flow velocity differs not only depending on the outside air temperature, but also on the required load capacity and battery temperature.

[0062] Returning to the explanation of the flowchart.

[0063] In step S130, the controller 50 operates the first valve 41 to the fifth valve 46, the battery pump 10, and the air conditioning system 5 based on the mixture ratio and air volume calculated in step S120, and starts temperature control of the battery 53.

[0064] In step S140, the controller 50 notifies the driver that the battery temperature control is being performed, for example, by displaying text information in the meter cluster. Note that the notification method is not limited to this. For example, an icon indicating the battery temperature control may be provided in the meter cluster and may be lit or flashed.

[0065] In step S150, the controller 50 determines whether there is any abnormality in the behavior of the temperature of the temperature control air or the battery temperature after the start of battery temperature control. If there is an abnormality, the process of step S160 is executed, and if there is no abnormality, the process returns to step S100. An abnormality here refers to, for example, when the temperature control air temperature is excessively high or low relative to the target temperature control air temperature, or when the battery temperature does not decrease despite temperature control for cooling.

[0066] In step S160, the controller 50 notifies the driver of the end of the battery temperature regulation control and issues a warning.

[0067] In step S170, the controller 50 transitions to fail state control and ends this routine. The fail state control is a control for enabling safe evacuation actions, such as limiting the output of a drive motor (not shown) or limiting the vehicle speed.

[0068] As described above, the battery temperature control system according to this embodiment controls the battery temperature using not only outside air but also low-temperature air, high-temperature air, or room-temperature air inside the air-conditioning case 5A. For example, by using low-temperature air, cooling performance for battery output during driving can be ensured. Furthermore, by setting the mixture ratio and air volume of the outside air, low-temperature air, high-temperature air, and room-temperature air according to each requirement, such as a temperature increase requirement or a heat retention requirement, the amount of energy consumed for controlling the battery temperature can be reduced.

[0069] (Modification) A modification of the above embodiment will now be described with reference to Figures 9 and 10. This modification, like the above embodiment, also falls within the scope of the present invention.

[0070] Fig. 9 is a schematic diagram of a battery temperature control system 1 according to this modification. The difference from Fig. 1 is that the system of this modification does not have the first valve 41 to the fifth valve 45, but is instead provided with a rotary valve 70. The rotary valve 70 is a so-called multi-flow valve that can selectively switch between multiple flow paths.

[0071] 10 is a schematic diagram of a rotary valve 70 that can be applied to this modification. However, the configuration of the rotary valve 70 is not limited to this.

[0072] The rotary valve 70 includes a valve case 71 and a rotary plate 72 housed in the valve case 71 .

[0073] The valve case 71 has a hollow cylindrical shape, and its inlet end surface 71A is provided with openings 81-86 to which the first air passage 31 to the fifth air passage 35 are connected. The openings 81-86 are arranged circumferentially at a predetermined interval so that air passages with similar temperature ranges flow adjacent to each other. Specifically, the first opening 81 is connected to the second air passage 32 through which low-temperature air flows. The second opening 82 and the fifth opening 85 are connected to branches of the first air passage 31 through which outside air flows. The third opening 83 is connected to the fourth air passage 35 through which room-temperature air flows. The fourth opening 84 is connected to the fifth air passage 35 through which air exhausted from the vehicle interior 8 flows. The sixth opening 86 is connected to the third air passage 34 through which high-temperature air flows. The valve case 71 also has one opening on its downstream end surface (not shown), which is connected to an air passage leading to the intake port of the battery pump 10.

[0074] Furthermore, a gap is provided between the first opening 81 and the sixth opening 86 that is large enough to block a through-hole 71A, which will be described later.

[0075] The rotating plate 72 is a disc-shaped member and has a through-hole 72A at a position offset from its center. The opening area of ​​the through-hole 72A is equal to or greater than the opening areas of the first to sixth openings 81-86. The rotating plate 72 is rotatably housed in the valve case 71 while in contact with the upstream end surface 71A. The mechanism for rotating the rotating plate 72 is not particularly limited. For example, a mechanism can be used in which the rotor shaft of an electric motor is connected to the center of the rotating plate 72 and the rotating plate is rotated by an electric motor fixed inside or outside the battery case 71.

[0076] Using the rotary valve 70 configured as described above, it is possible to select the air drawn into the battery pump 10 and adjust the mixture ratio by rotating the rotary plate 72. For example, when only low-temperature air is used for temperature control in the cooling mode, the through-hole 72A is connected to the first opening 81. When only high-temperature air is used for temperature control in the heating mode, the through-hole 72A is connected to the sixth opening 86. In the parking mode, the rotary plate 72 is rotated so that the through-hole 72A is positioned between the first opening 81 and the sixth opening 86, and the through-hole 72A is not connected to any opening.

[0077] Furthermore, when a mixture of cooled / warm air and outside air is used as temperature-regulating air in the cooling mode, the rotating plate 72 is rotated so that the center of the through-hole 72A is positioned between the center of the first opening 81 and the center of the second opening 82, and the through-hole 72A is communicated with a part of the first opening 81 and a part of the second opening 82. In this case, the mixing ratio can be adjusted by changing the rotation angle of the rotating plate 72, that is, by changing the ratio between the communication area between the through-hole 72A and the first opening 81 and the communication area between the through-hole 72A and the second opening 82.

[0078] 1, a configuration using first valve 41 to fifth valve 45 not only increases the number of valves, but also increases the number of connections between the inlet and outlet sides of the valves. This results in issues such as increased costs and limited layout flexibility. In contrast, the configuration of this modified example can reduce the number of valves, thereby solving these issues.

[0079] In this modified example, the rotary valve 70 is configured independent of the battery pump 10, but this is not limited to this, and for example, the rotary valve 70 may be integrated into the suction side of the battery pump 10.

[0080] As described above, in this embodiment, a battery temperature control method is provided for controlling a battery temperature adjustment system 1 including: an air conditioning case 5A that houses a heat exchanger 3, a heating device 2, and a regulator 4 that adjusts the mixing ratio of the air that has passed through the heat exchanger 3 and the air that has passed through the heating device 2; a first air passage 31 that supplies outside air introduced into the air conditioning case 5A from the air conditioning case 5A to the battery case 9; a second air passage 32 that supplies air that has passed through the heat exchanger 3 from the air conditioning case 5A to the battery case 9; a third air passage 33 that supplies air that has passed through the heating device 2 from the air conditioning case 5A to the battery case 9; a fourth air passage 34 that supplies air that has passed through the regulator 4 from the air conditioning case 5A to the battery case 9; a fifth air passage 35 that supplies air within the vehicle compartment 8 to the battery case 9; and an internal case passage 51 that is a passage for adjusting the battery temperature and is provided within the battery case 9. In this method, the controller 50 adjusts the amount of air supplied to the battery case 9 from each of the first air passage 31 to the fifth air passage 35 in accordance with the temperature of the battery 53. In other words, the controller 50 adjusts the mixture ratio of outside air, low-temperature air, high-temperature air, room temperature air, and air discharged from the passenger compartment 8 in the temperature-control air. This allows for higher cooling performance than a configuration in which the battery 53 is cooled only by outside air. Furthermore, the amount of energy consumed to control the battery temperature can be reduced compared to a configuration in which the battery 53 is cooled only by low-temperature air or a configuration in which the battery 53 is heated only by high-temperature air.

[0081] In this embodiment, the battery temperature control system 1 includes a battery pump (air pump) 10, and the air flowing through the first air passage 31 to the fifth air passage 35 joins together and passes through the battery pump 10 before being supplied to the case interior passage 41. As a result, the temperature control air, which is a mixture of air of different temperatures, is agitated by the battery pump 10, reducing temperature variations in the temperature control air flowing through the case interior passage 51.

[0082] In this embodiment, when air is supplied from a plurality of passages among the first air passage 31 to the fifth air passage 35, the controller 50 adjusts the humidity of the air supplied to the battery case 9 by mixing the air with air that has been dehumidified by passing through the heat exchanger 3. This makes it possible to suppress the occurrence of condensation inside the battery case 9.

[0083] In this embodiment, when switching the path of the air supplied to the battery case 9, the controller 50 adjusts the amount of air supplied from each air passage 31-35 to suppress the temperature difference that occurs inside the battery case 9. This makes it possible to suppress the uneven distribution of battery temperature.

[0084] In this embodiment, the controller 50 sets the flow rate and temperature of the air supplied to the battery case 9, thereby reducing the energy required to adjust the temperature of the temperature-controlling air (air supplied to the battery case 9) required in accordance with the required load capacity of the battery temperature control system 1. This increases the efficiency of battery temperature control.

[0085] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

Claims

1. A battery temperature control method for controlling a battery temperature control system including an air conditioning case accommodating a heat exchanger, a heating device, and a regulator that adjusts the mixing ratio of air that has passed through the heat exchanger and air that has passed through the heating device; a first air passage that supplies outside air introduced into the air conditioning case from the air conditioning case to a battery case; a second air passage that supplies air that has passed through the heat exchanger from the air conditioning case to the battery case; a third air passage that supplies air that has passed through the heating device from the air conditioning case to the battery case; a fourth air passage that supplies air that has passed through the regulator from the air conditioning case to the battery case; a fifth air passage that supplies air from inside the vehicle cabin to the battery case; an internal case passage that is provided within the battery case and is used to regulate battery temperature; and a sixth air passage that recirculates air that has passed through the internal case passage to the battery case, the method comprising: a controller adjusting the amount of air supplied to the battery case from each of the first air passage to the sixth air passage according to the temperature of the battery; Battery temperature control method.

2. A battery temperature control method according to claim 1, wherein the battery temperature regulation system is provided with an air blower pump, and the air flowing from the first air passage to the sixth air passage joins together and passes through the air blower pump before being supplied to the passage inside the case.

3. A battery temperature control method as described in claim 1, wherein when air is supplied from a plurality of passages among the first air passage to the sixth air passage, the controller adjusts the humidity of the air supplied to the battery case by mixing air that has been dehumidified by passing through the heat exchanger.

4. A battery temperature control method as described in claim 1, wherein the controller, when switching the path of the air supplied to the battery case, adjusts the amount of air supplied from each air passage to suppress the temperature difference occurring inside the battery case.

5. A battery temperature control method as described in claim 1, wherein the controller sets the flow rate and temperature of the air supplied to the battery case, thereby reducing the energy required to adjust the temperature of the air supplied to the battery case according to the required load capacity of the battery temperature control system.

6. A battery temperature control system comprising: an air conditioning case accommodating a heat exchanger, a heating device, and a regulator that adjusts the mixing ratio of air that has passed through the heat exchanger and air that has passed through the heating device; a first air passage that supplies outside air introduced into the air conditioning case from the air conditioning case to a battery case; a second air passage that supplies air that has passed through the heat exchanger from the air conditioning case to the battery case; a third air passage that supplies air that has passed through the heating device from the air conditioning case to the battery case; a fourth air passage that supplies air that has passed through the regulator from the air conditioning case to the battery case; a fifth air passage that supplies air from inside the vehicle cabin to the battery case; an internal case passage that is provided within the battery case and is a passage for battery temperature control; and a sixth air passage that recirculates air that has passed through the internal case passage to the battery case, the battery temperature control system further comprising a controller that adjusts the amount of air supplied to the battery case from each of the first air passage to the sixth air passage in accordance with the temperature of the battery.

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