JP6791075B2 - Power storage device cooling system - Google Patents

Description

The present disclosure relates to a cooling system for a power storage device, and more specifically to a cooling system for cooling a power storage device mounted in a luggage compartment of a vehicle.

In recent years, vehicles such as hybrid vehicles or electric vehicles equipped with a power storage device have become widespread. Generally, when the temperature of the power storage device rises excessively, the charge / discharge performance of the power storage device deteriorates and the deterioration rate of the power storage device increases. Therefore, a cooling system is provided in the power storage device in the vehicle. In many vehicles, a power storage device is installed in a luggage room (luggage room) at the rear of the vehicle, and various techniques for cooling such the power storage device have been proposed.

For example, in FIG. 1 of Japanese Patent Application Laid-Open No. 2016-117366 (Patent Document 1), in a cooling system of a power storage device applied to a vehicle in which a power storage device is mounted in a luggage room, a cabin (vehicle compartment) and a power storage device are shown. A configuration is disclosed in which a duct for communicating, a blower provided in the duct for sucking air in the cabin and sending it to a power storage device, and a communication port for returning the air after cooling the power storage device to the inside of the cabin are provided. ing. In this configuration, the air in the cabin is taken in by the blower to cool the power storage device. The air after cooling the power storage device is exhausted into the luggage room, and a part of the air returns to the cabin through the communication port.

Japanese Unexamined Patent Publication No. 2016-117366 Japanese Unexamined Patent Publication No. 2016-134322 Japanese Unexamined Patent Publication No. 2013-158128

Under conditions of low outside air temperature, such as in winter, the vehicle (for example, the rear glass) can be cooled by the outside air and become cold. In the cooling system configuration as described above, the air returning from the luggage room to the cabin flows along the rear glass. Therefore, the air (cold air) that has become cold due to contact with the rear glass may reach the user sitting in the rear seat and cause discomfort to the user.

As a measure to prevent the user's comfort from being impaired, when the intake air temperature from the cabin is less than the predetermined temperature, the amount of intake air from the blower should be reduced as compared with the case where the intake air temperature is above the predetermined temperature. Can be considered. The intake air temperature can be detected by providing an intake air temperature sensor in the duct. However, if the intake air temperature sensor is provided, an extra member cost will be incurred. In addition, since an abnormality such as a failure may occur in the intake air temperature sensor, it is necessary to take measures against it. Therefore, there is a demand for a method of controlling the intake amount of the blower without providing an intake air temperature sensor, thereby not causing discomfort to the user.

As such a method, the elapsed time from the start-up of the vehicle's electric system (so-called vehicle Ready ON) is used, and when the elapsed time is shorter than the reference time, the elapsed time is longer than the reference time. Compared with this, it is conceivable to suppress the intake amount of the blower. By executing such control, it is possible to appropriately suppress the intake air amount of the blower without providing the intake air temperature sensor, and it is possible to prevent the user's comfort from being impaired.

However, in the above control, the intake amount of the blower is uniformly suppressed from the time when the electric system of the vehicle is started until the reference time elapses, and the cooling capacity of the power storage device is lowered. Then, for example, when the temperature of the power storage device has risen due to the previous run, the high temperature state of the power storage device may be easily maintained.

The present disclosure has been made to solve the above problems, and an object of the present invention is to provide a user with an intake air temperature sensor in a cooling system of a power storage device for cooling a power storage device mounted on a vehicle without providing an intake air temperature sensor. It is to provide a technique capable of appropriately cooling a power storage device while suppressing the discomfort of the above.

A power storage device cooling system according to an aspect of the present disclosure cools a power storage device mounted in the luggage compartment of a vehicle. The cooling system of the power storage device is a duct that connects the vehicle interior and the power storage device, a blower that is installed in the duct and takes in the air in the vehicle interior and sends it to the power storage device, and air in the luggage compartment after cooling the power storage device. It is equipped with a communication port for returning to the passenger compartment and a control device. The control device controls the blower so that when the elapsed time from the start of the vehicle's electric system is shorter than the reference time, the intake amount of the blower is reduced as compared with the case where the elapsed time is longer than the reference time. To do. The control device sets the reference time shorter as the time between the previous stop of the electric system and the start of the current electric system is shorter.

If the elapsed time from the start of the vehicle's electrical system is less than the reference time, the user has not yet operated the air conditioner, or even if the user is operating the air conditioner, the interior of the vehicle is sufficiently warm. It is considered that it is not. Therefore, the intake air temperature of the blower is likely to be low. Therefore, according to the above configuration, the control device reduces the intake amount of the blower as compared with the normal state. On the other hand, when the elapsed time is equal to or longer than the reference time, the intake air temperature of the blower may be raised to some extent by the user operating the air conditioner to warm the passenger compartment. Therefore, the control device relaxes the suppression of the intake amount of the blower. By such control, the power storage device can be appropriately cooled while suppressing discomfort to the user.

Further, the shorter the time (so-called IG-OFF time) from the previous stop of the electric system, the shorter the reference time is calculated. If the time from the stop of the electric system is short, not much time has passed since the IG-OFF operation was performed, and the temperature inside the vehicle that was warmed during the previous run (≈ blower intake temperature) It is likely that it is maintained at a relatively high temperature. Therefore, even if the reference time is set shorter as the above time is shorter and the intake amount of the blower is returned to the normal amount at an early stage, the user is less likely to feel uncomfortable. Further, by increasing the intake amount of the blower at an early stage, it becomes possible to cool the power storage device more appropriately.

According to the present disclosure, in the cooling system of the power storage device for cooling the power storage device mounted on the vehicle, the power storage device is appropriately cooled while suppressing discomfort to the user without providing an intake air temperature sensor. be able to.

It is a figure which shows schematic the structure of the vehicle which mounted the cooling system of the battery pack which concerns on this embodiment. It is a figure which shows an example of the relationship between the IG-OFF time and the intake air temperature. It is a flowchart for demonstrating the cooling control of a battery pack in this embodiment. It is a figure for demonstrating an example of a map MP. It is a figure which shows an example of the relationship between the elapsed time after Ready-ON, the heating temperature, and the intake air temperature.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

[Embodiment]
<Battery pack cooling system configuration>
FIG. 1 is a diagram schematically showing a configuration of a vehicle equipped with a battery pack cooling system according to the present embodiment. The vehicle 1 is an electric vehicle such as a hybrid vehicle (including a plug-in hybrid vehicle), an electric vehicle, or a fuel cell vehicle, and is a cabin 2 and a luggage room (luggage room) provided behind the cabin (cabin) 2. ) 3 and.

A rear seat 4 is arranged in the cabin 2. A package tray 5 for partitioning the cabin 2 and the luggage room 3 is provided above the rear side of the rear seat 4. A rear glass 6 is provided above the package tray 5.

Inside the luggage room 3, a battery pack 7 that supplies electric power to a motor generator (not shown) and a cooling system 10 for cooling the battery pack 7 are arranged.

The battery pack 7 includes a battery module (not shown) configured by electrically connecting a plurality of cells, a battery temperature sensor 71, and a battery case (not shown) for accommodating the battery module. Has been done. On the rear side of the battery pack 7, an exhaust port 8 for exhausting the air that has cooled the battery module in the battery pack 7 to the luggage room 3 is provided.

Each cell included in the battery module is a secondary battery such as a nickel hydrogen battery, but may be another secondary battery such as a lithium ion secondary battery. Further, each cell may be a capacitor such as an electric double layer capacitor. The battery pack 7 corresponds to the "power storage device" according to the present disclosure.

The battery temperature sensor 71 detects the temperature (hereinafter, also referred to as “battery temperature”) TB of the battery module, and outputs the detection result to the ECU 100.

The cooling system 10 includes an intake duct 11, a blower 12, a communication port 13, and an ECU 100.

One end of the intake duct (corresponding to the "duct" according to the present disclosure) 11 is opened in the cabin 2, and the other end of the intake duct 11 is connected to the battery pack 7. That is, the intake duct 11 communicates the cabin 2 with the battery pack 7.

The blower 12 is provided in the intake duct 11, takes in the air in the cabin 2, and sends the air (cooling air) to the battery module (not shown) inside the battery case of the battery pack 7.

The communication port 13 is provided in the package tray 5 and communicates with the cabin 2 and the luggage room 3. The number of communication ports 13 is not particularly limited, and may be one or a plurality.

Although not shown, the ECU 100 includes a CPU (Central Processing Unit), a memory, a buffer, and a timer. The ECU 100 controls the blower 12 based on the detected value (battery temperature TB) of the battery temperature sensor and the program stored in the memory. A part or all of the ECU 100 may be configured to execute arithmetic processing by hardware such as an electronic circuit.

<Blower control>
When the blower 12 is driven in the cooling system 10 of the battery pack 7 configured as described above, the air in the cabin 2 is sent to the battery pack 7 via the intake duct 11 (see arrow AIR1). The air sent to the battery pack 7 exchanges heat with the battery module (not shown) to cool the battery module. The air after heat exchange is discharged from the exhaust port 8 to the luggage room 3 behind the battery pack 7 (see arrow AIR2). The air in the luggage room 3 is pushed out from the communication port 13 provided in the package tray 5 by the air discharged from the exhaust port 8 and flows into the cabin 2 (see arrow AIR3).

The air returning from the luggage room 3 to the cabin 2 flows along the rear glass 6 as shown by the arrow AIR3. In a situation where the outside air temperature is low, such as in winter, the rear glass 6 may be cooled by the outside air to a low temperature. In such a case, the air (cold air) that has become cold due to contact with the rear glass 6 reaches the user sitting in the rear seat 4. As a result, it may cause discomfort to the user.

As a measure for suppressing such discomfort, when the intake air temperature T _in of the cabin 2 is lower than the predetermined temperature, and intake air temperature T _in is compared with the case of the above predetermined temperature, the intake air amount of the blower 12 It is possible to reduce it. The intake air temperature can be detected by providing an intake air temperature sensor (not shown) in the intake air passage (any place of the intake duct 11) (for example, the intake air temperature sensor 26 described in FIG. 2 of Patent Document 1). See).

However, if such an intake air temperature sensor is provided, an extra member cost will be incurred. In addition, since an abnormality of the intake air temperature sensor may occur, it is necessary to take measures against it. More specifically, the regulations of each country may require the detection of an abnormality in the intake air temperature sensor. However, the required detection accuracy and detection frequency should be achieved and the above regulations should be satisfied without incurring excessive costs such as providing a sensor different from the intake air temperature sensor or duplicating the intake air temperature sensor. Is difficult. Therefore, it is desirable to control the intake air amount of the blower 12 without providing the intake air temperature sensor so as not to cause discomfort to the user.

Therefore, in the present embodiment, the intake amount of the blower 12 is reduced by using the elapsed time Δt from the start-up of the electric system of the vehicle 1 (so-called Ready ON of the vehicle 1) without providing the intake air temperature sensor. More specifically, when the elapsed time Δt is shorter than the reference time t _REF is the elapsed time Δt is compared with a case longer than the reference time t _REF, reducing the intake air amount of the blower 12.

In such control, if a fixed value is adopted as the reference time t _REF , the intake amount of the blower 12 is uniformly suppressed from the start of the electric system of the vehicle 1 until the reference time t _REF elapses. Then, for example, when the battery temperature TB rises and the temperature inside the cabin 2 also rises due to the previous running, the battery temperature TB may be maintained at a high state.

In the vehicle 1, the charging / discharging of the battery pack 7 is controlled so that the charging power does not exceed the control upper limit value Win and the discharge power does not exceed the control upper limit value Wout. The absolute values of the control upper limit values Win and Wout are set so as to decrease as the battery temperature TB rises. Therefore, as the battery temperature TB rises, the charging / discharging restrictions of the battery pack 7 may become stricter. Then, for example, when the vehicle 1 is a hybrid vehicle, it becomes difficult to utilize the battery pack 7 due to the limitation of charge / discharge, and the engine must be driven by that amount. As a result, fuel economy may deteriorate.

Therefore, in the present embodiment, a configuration is adopted in which the time from when the electric system of the vehicle 1 is stopped (IG-OFF) in the previous trip until the electric system is started is further considered. Hereinafter, this time is also referred to as “IG-OFF time Δt _OFF ”. The IG-OFF time Δt _OFF corresponds to the “time between the previous stop of the electric system and the start of the current electric system” according to the present disclosure.

<Relationship between IG-OFF time and intake air temperature>
FIG. 2 is a diagram showing an example of the relationship between the IG-OFF time Δt _OFF and the intake air temperature Tin. 2, the horizontal axis represents the IG-OFF time Delta] t _OFF, the vertical axis represents the intake air temperature _{T in.} As shown in FIG. 2, intake air temperature _{T in} accordance with IG-OFF time Delta] t _OFF is lengthened decreases. From a different point of view, when the IG-OFF time Δt _OFF is short, that is, when the time has not passed since the electric system of the vehicle 1 was stopped, the inside of the cabin 2 is cooled by heat exchange with the outside air. Orazu, intake air temperature T _in are also maintained at a relatively high state (details will be described later).

<Battery pack cooling control flow>
FIG. 3 is a flowchart for explaining the cooling control of the battery pack 7 in the present embodiment. This flowchart is called and executed from the main routine after the Ready ON of the vehicle 1, for example, every predetermined period elapses. Each step (hereinafter abbreviated as "S") in this flowchart is basically realized by software processing by the ECU 100, but may be realized by hardware (electronic circuit) manufactured in the ECU 100. ..

The ECU 100 uses a timer (not shown) in another routine (not shown), for example, to turn off the IG-OFF time Δt _{OFF after} the electric system of the vehicle 1 is stopped (IG-OFF) in the previous trip. It is assumed that the counting is performed.

In S10, the ECU 100 acquires the battery temperature TB from the battery temperature sensor 71 provided in the battery pack 7.

In S20, the ECU 100 determines whether or not the battery temperature TB acquired in S10 is equal to or higher than a predetermined determination temperature. The determination temperature is a temperature determined by an experiment or a simulation so that the charge / discharge performance of the battery pack 7 does not deteriorate and the deterioration rate of the battery pack 7 does not become excessively high. The determination temperature is stored in advance in a memory (not shown) of the ECU 100.

When the battery temperature TB is lower than the determination temperature (NO in S20), the ECU 100 determines that the battery pack 7 does not need to be cooled in particular, proceeds to S30, and stops the blower 12. If the blower 12 is already stopped, the stopped state of the blower 12 is maintained.

On the other hand, when the battery temperature TB is equal to or higher than the determination temperature (YES in S20), the ECU 100 determines that the battery pack 7 needs to be cooled. Then, the ECU 100 acquires the IG-OFF time Δt _OFF counted in the above-mentioned separate routine (S40).

In S50, the ECU 100 calculates a reference time t _REF that is appropriately set based on the time required to heat the inside of the cabin 2 by an air conditioner (not shown) to raise the temperature inside the cabin 2. The reference time t _REF is, for example, a time of about several minutes to a dozen minutes, and is calculated from the IG-OFF time Δt _OFF by referring to the map MP as described below.

FIG. 4 is a diagram for explaining an example of the map MP. In the map MP, the horizontal axis represents the IG-OFF time and the vertical axis represents the reference time t _REF . The map MP is determined, for example, based on the results of prior experiments, and is stored in advance in the memory (not shown) of the ECU 100.

With reference to FIG. 4, in the map MP, the correlation between the IG-OFF time Δt _OFF and the reference time t _REF is defined so that the shorter the IG-OFF time Δt _OFF is, the shorter the reference time t _REF is. There is. By referring to the map MP, the reference time t _REF can be calculated from the IG-OFF time Δt _OFF . Although an example of using the map MP will be described here, a relational expression (function or the like) may be used instead of the map MP.

Returning to FIG. 3, in S60, the ECU 100 uses a timer (not shown) to calculate the elapsed time Δt from the Ready ON of the vehicle 1. Then, the ECU 100 compares the elapsed time Δt with the reference time t _REF calculated in S50 (S70).

When the elapsed time Δt is equal to or greater than the reference time t _REF , that is, when a certain amount of time (for example, a time of several minutes to a dozen minutes) has elapsed from the time of ReadyON (YES in S70), even when ReadyOn It is considered that the user operates the air conditioner (not shown) even if the temperature inside the cabin 2 is low, thereby warming the inside of the cabin 2. As a result, the intake air temperature of the blower 12 may be high to some extent. Therefore, the ECU 100 advances the process to S90, drives the blower 12 (or keeps the blower 12 in the driven state), and sets the intake amount of the blower 12 to the normal amount IN1.

On the other hand, when the elapsed time Δt is less than the reference time t _REF (NO in S60), the user has not yet operated the air conditioner, or even if the user is operating the air conditioner, the inside of the cabin 2 is inside. It is thought that it has not warmed up sufficiently. Therefore, the intake air temperature of the blower 12 is likely to be low. Therefore, the ECU 100 advances the process to S80 to drive the blower 12 (or maintain the driving state of the blower 12), and sets the intake amount of the blower 12 to IN2, which is lower than the normal amount IN1 (IN2 <IN1).

Here, it is also conceivable to set the reference time t _REF as a fixed value. However, in that case, the intake amount of the blower 12 is uniformly suppressed until the elapsed time Δt reaches the reference time t _REF . As a result, for example, when the battery temperature TB has risen due to the previous run, the state where the battery temperature TB is high may be easily maintained.

On the other hand, according to the present embodiment, by using the map MP (see FIG. 4), the shorter the IG-OFF time Δt _OFF , the shorter the reference time t _REF is calculated. When the IG-OFF time Δt _OFF is short, it has not been so long since the IG-OFF operation of the vehicle 1 was performed, so that the temperature inside the cabin 2 warmed during the previous run (in other words, the blower). It is highly possible that the intake air temperature (12) is maintained at a relatively high temperature. Therefore, the shorter the IG-OFF time Δt _OFF , the shorter the reference time t _REF is set, and even if the intake amount of the blower 12 is increased from the low amount IN2 to the normal amount IN1 at an early stage, the user is uncomfortable. Hateful. On the other hand, the battery pack 7 can be appropriately cooled by increasing the intake amount of the blower 12 at an early stage.

<Measurement result>
Figure 5 is a diagram showing the elapsed time after Ready-ON Delta] t and the heating temperature _{T h,} an example of a measurement result of the relationship between the intake air temperature _{T in.} In FIG. 5, the horizontal axis represents the elapsed time Δt, and the vertical axis represents the temperature. With reference to FIG. 5, the heating temperature _Th is a value obtained by actually measuring the air temperature from the air conditioner to the cabin 2 by installing a temperature sensor (not shown) in the air passage from the air conditioner (not shown). Further, the intake air temperature T _in is a value obtained by measuring the intake air temperature by installing an intake air temperature sensor (not shown) in the intake duct 11.

At the time of Ready ON (time t0), the intake amount of the blower 12 is set to a low amount IN2. The intake air temperature _{T in} accordance with the heating temperature _{T h} rises also rises. When the elapsed time Δt reaches the reference time t _REF at the time t1, the intake amount of the blower 12 is switched from the low amount IN2 to the normal amount IN1. After that, the intake amount of the blower 12 is maintained at the normal amount IN1. Note that after time t2, the heating temperature T _h although still increases, the intake air temperature T _in it is understood that substantially constant.

As described above, according to the present embodiment, by using the elapsed time Δt from the time of Ready ON of the vehicle 1, the intake air amount of the blower 12 is appropriately suppressed (reduced) even if the intake air temperature sensor is not provided. Can be done. As a result, it is possible to prevent the user from being exposed to cold air and impairing the comfort of the user. Further, since the intake air temperature sensor can be omitted, the member cost can be reduced, and it is possible to eliminate the need for countermeasures against the failure of the intake air temperature sensor.

Further, according to the present embodiment, as shown in the map MP (see FIG. 4), the shorter the IG-OFF time Δt _OFF , the shorter the reference time t _REF . When the IG-OFF time Δt _OFF is short, it is highly possible that the temperature inside the cabin 2 is maintained at a high state to some extent. Therefore, as the IG-OFF time Δt _OFF is shorter, the reference time t _REF is shortened, so that the intake amount of the blower 12 tends to be a relatively large amount IN1. Thereby, for example, even if the temperature of the battery pack 7 has risen due to the previous running, the battery pack 7 can be appropriately cooled to prevent the battery temperature TB from rising excessively.

In the present embodiment, the configuration for not providing the intake air temperature sensor has been described, but since there is a correlation between the intake air temperature from the cabin 2 and the outside air temperature, it is also possible to provide the outside air temperature sensor. , It is possible to estimate the intake air temperature. According to this embodiment, the outside air temperature sensor can also be omitted.

The embodiments disclosed this time should be considered as exemplary in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the description of the embodiment described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Vehicle, 2 Cabin, 3 Luggage Room, 4 Rear Seat, 5 Package Tray, 6 Rear Glass, 7 Battery Pack, 71 Battery Temperature Sensor, 8 Exhaust Port, 10 Cooling System, 11 Intake Duct, 12 Blower, 13 Communication Port, 100 ECU.

Claims (1)

It is a cooling system of the power storage device for cooling the power storage device mounted in the luggage compartment of the vehicle.
A duct that connects the passenger compartment and the power storage device,
A blower provided in the duct, which takes in the air in the vehicle interior and sends it to the power storage device,
A communication port for returning the air in the luggage compartment after cooling the power storage device to the passenger compartment, and
When the elapsed time from the start of the electric system of the vehicle is shorter than the reference time, the blower is operated so as to reduce the intake amount of the blower as compared with the case where the elapsed time is longer than the reference time. Equipped with a control device to control
The control device is a cooling system for a power storage device that sets the reference time shorter as the time between the previous stop of the electric system and the start of the electric system this time is shorter.

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