JP7276710B2 - battery cooling system - Google Patents

Description

The present invention relates to a battery cooling system for cooling batteries.

In the battery cooling system, as shown in Patent Document 1, a heat insulating sheet is inserted between the battery and the cold storage material when not cooled, and the heat insulating sheet is removed when cooling, and the cold storage material is brought into contact with the battery. It has been proposed to move According to this, the battery can be cooled or not cooled as required.

By the way, it is desirable to maintain the temperature of the lithium-ion battery at about human skin temperature from the viewpoint of battery life. Therefore, it is desirable to adjust the temperature of the battery to prevent it from becoming too hot or too cold. As a means for adjusting the temperature, it is conceivable to use a phase change material made of paraffinic hydrocarbon or the like. Specifically, if the phase change material is enclosed in a bag-like storage container (bag) and placed in contact with the surface of the battery, the phase change material is heated to a higher temperature in the battery than the phase change material. At some point, due to the temperature difference, heat is absorbed from the solid phase, so that the liquid phase and the solid phase gradually mix and the liquid phase ratio increases without temperature change, that is, the state of latent heat, and finally Only the liquid phase is present at If this latent heat state is used to cool the battery, the temperature of the phase-change material in contact with the battery surface is uniform in the plane direction, so the temperature distribution on the battery surface can be made nearly uniform. It is possible to suppress the deterioration of the battery life (suppression of deterioration due to uneven temperature distribution of the battery).

JP 2012-248363 A

However, in the above case, since the storage container that stores the phase change material is placed in contact with the surface of the battery, the phase change material can be used as long as there is a temperature difference between the phase change material and the battery. Heat is absorbed, and heat is absorbed from the battery even when it is desired to keep the battery warm, such as when the vehicle is parked in winter. For this reason, there is a problem that the battery is quickly cooled down to about the outside temperature.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery capable of suppressing heat absorption by a phase change material with respect to the battery without moving a container containing the phase change material when the battery does not need to be cooled. To provide a cooling system.

In order to achieve the above objects, the present invention has the following configurations (1) to (5).

(1) A battery cooling system comprising:
a container that abuts against the surface of the battery;
an airbag disposed within the container;
a phase-change material that is housed in the storage container between the storage container and the airbag and that changes phases between a solid phase and a liquid phase;
a gas supply passage having one end open in the airbag and the other end extending outside the airbag;
a gas supply unit connected to the other end of the gas supply path and supplying gas toward the inside of the airbag;
a liquid-solid equilibrium detection unit that detects the liquid-solid equilibrium state of the phase change material;
an ambient temperature acquisition unit that acquires the ambient temperature of the battery;
It is determined that the phase-change material is in a liquid-solid equilibrium state based on the detection information from the liquid-solid equilibrium state detection unit, and based on the ambient temperature acquired from the ambient temperature acquisition unit, the ambient temperature is higher than a predetermined temperature. a control unit that controls the gas supply unit to increase the amount of gas supplied to the inside of the airbag when the ambient temperature is determined to be lower than that when the ambient temperature is equal to or higher than the predetermined temperature;
is provided.

According to this configuration, when the phase change material is in a liquid-solid equilibrium state and the ambient temperature of the battery is lower than the predetermined temperature, the amount of gas supplied to the airbag increases more than when the ambient temperature is equal to or higher than the predetermined temperature. As a result, the inflation and deployment of the airbag pushes away the solid phase portion in the phase change material between the airbag and the inner plate surface on one side in the thickness direction of the container 8 together with the liquid phase portion. As a result, the heat absorption efficiency of the battery heat by the phase change material can be reduced, and even if the storage container containing the phase change material is in contact with the surface of the battery, the temperature drop of the battery can be suppressed. In addition, the gas in the airbag can form a gas layer between the surrounding atmosphere of the battery and the battery. Therefore, when the battery does not need to be cooled, the phase change material can effectively absorb heat from the battery without moving the container containing the phase change material or extracting the phase change material from the container. A controllable battery cooling system can be provided.

(2) Under the configuration of (1) above,
The airbag is installed in the storage container so as to extend along the surface of the battery with which the storage container abuts.

According to this configuration, the effect of suppressing the temperature drop of the battery by the airbag can be obtained for a wide range of the surface of the battery with which the storage container is in contact, and the temperature drop of the battery can be suppressed more effectively.

(3) Under the configuration of (1) or (2) above,
The battery is disposed in a vehicle,
Having a parking detection unit that detects that the vehicle is parked,
The control unit is configured to allow execution of the heat retention control when it is determined that the vehicle is parked based on the detection information from the parking detection unit.

According to this configuration, it is possible to specifically execute the heat retention control assuming the scene where the battery is most desired to be kept in the heat retention state.

(4) Under the configuration of any one of (1) to (3) above,
The battery is disposed in a vehicle equipped with an engine,
The inside of the airbag is connected to an intake manifold of the engine through an exhaust passage having an on-off valve,
The control unit is configured to open the on-off valve only during a predetermined period when an IG-ON signal is received from the ignition switch.

According to this configuration, when the engine is started with the IG-ON, the inside of the intake manifold becomes a negative pressure (below the atmospheric pressure), and the negative pressure inside the intake manifold is eliminated without taking any special measures or treatments. By using this, the air inside the airbag can be extracted at the precise timing of engine start.

(5) Under the configuration of (1) or (2) above,
In claim 1 or 2,
A parking detection unit that detects that the vehicle is parked, and a battery temperature detection unit that detects the temperature of the battery,
The control unit determines that the vehicle is parked based on detection information from the parking detection unit during execution of the heat retention control, and the temperature of the battery rises based on temperature information from the battery temperature detection unit. When it is determined that the condition is present, the amount of gas supplied to the inside of the airbag is set to be less than when the heat retention control is being executed.

According to this configuration, even under the heat retention control execution condition, when the battery is parked and the temperature of the battery has risen due to charging or the like, the temperature of the battery is allowed to rise based on the decrease in the amount of gas supplied to the airbag. It is possible to prevent the temperature from rising above the upper limit temperature.

According to the present invention, when the battery does not need to be cooled, the phase change material absorbs heat from the battery without moving the container containing the phase change material or removing the phase change material from the container. A controllable battery cooling system can be provided.

1 is an overall configuration diagram simply showing a cooling system for a battery according to an embodiment; FIG. FIG. 3 is an exploded explanatory view illustrating a cooling structure around the battery for cooling the battery; FIG. 4 is an explanatory diagram simply explaining cooling of the battery by the cooling unit according to the embodiment; FIG. 4 is an explanatory diagram simply explaining suppression of cooling of the battery by the cooling unit according to the embodiment; The figure which looked at the internal structure of the container which concerns on embodiment from the thickness direction other side of the container. The figure which looked at the internal structure of the container which concerns on embodiment from the thickness direction one side of the container. 3 is a block diagram showing an outline of the functional configuration of a control unit according to the embodiment; FIG. Explanatory drawing explaining the basic control content of the cooling system which concerns on embodiment. 4 is a flowchart showing control details of the cooling system according to the embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a cooling system for cooling the battery 2 according to the first embodiment. This cooling system 1 is mounted on a vehicle in this embodiment.

The battery 2 is constructed by stacking a plurality of battery cells 3, as shown in FIG. Each battery cell 3 is formed in a flat plate shape, and its plate surface is formed in a rectangular shape. A positive electrode cell terminal 3a and a negative electrode cell terminal 3b are provided on one side surface of each battery cell 3 in the direction in which the short side extends, and are spaced apart in the direction in which the long side extends. A constant voltage is output from the terminal 3b. Each of the plurality of battery cells 3 is formed in a rectangular parallelepiped shape by being stacked with the positive electrode cell terminal 3a and the negative electrode cell terminal 3b of each battery cell 3 facing upward. By connecting the cells 3 in series, the plurality of battery cells 3 are supposed to output a predetermined voltage as the battery 2 . In addition, in FIG. 1, the battery 2 is illustrated in a simplified manner.

Specifically, a lithium-ion battery, for example, is used for such a battery 2 . Lithium-ion batteries have an optimum temperature range from the viewpoint of power capacity and deterioration suppression, and the temperature range is, for example, 25°C to 60°C. Therefore, when the battery 2 is mounted in the engine room of a vehicle, a cooling system 1 for the battery 2 that is independent of the cooling system of the engine is required.

The cooling system 1 includes a plurality of (five in this embodiment) cooling units 4, a housing 5, an air supply device 6 as a gas supply device, and an air discharge device 7 as a gas discharge device. ing.

As shown in FIGS. 2 to 4, each of the plurality of cooling units 4 includes a thick plate-like (having a rectangular plate surface) hollow housing container 8, an airbag 9 housed in the housing container 8, and a storage container 8. A phase change material 10 is contained within the container 8 and between the containing container 8 and the airbag 9 . The storage container 8 in each of the plurality of cooling units 4 is a pouch-shaped storage container that can be deformed in accordance with the volume change of the phase change material described later. ) are in close contact with (contact with) each of the other five constituent surfaces of the battery 2 excluding the upper constituent surface (terminal-existing surface). A material having high thermal conductivity is used as a material for each storage container 8, and each storage container 8 is, for example, a pouch-shaped container formed of rust-resistant metals (aluminum, stainless steel) or the like. used. In this embodiment, as some of the containers 8 (two in this embodiment), those having an outer plate surface area relatively smaller than the surface area of the battery 2 are used. (Refer to FIG. 2), which takes into consideration the arrangement space for the related parts of the battery 2 and the like. Of course, from the viewpoint of improving the cooling performance, it is preferable to adopt a configuration in which the outer plate surface of each storage container 8 is brought into contact with the entire surface of each component of the battery 2 . In FIG. 1, two cooling units 4 (container 8) are simply shown, and in FIGS. 3 and 4, only one cooling unit 4 (container 8) is shown simply. there is

The airbag 9 is held in the storage container 8 via a frame body 11, as shown in FIGS. The frame body 11 has a rectangular (frame-shaped) first frame portion 12 which is slightly smaller than the plate surface of the container 8, and a pair of intersecting wire rods 13a. and a second frame portion 13 passing through 12 facing vertices and extending outside the frame, and the first frame portion 12 and the second frame portion 13 are integrated at the intersection of the both 12 and 13. . The frame body 11 is arranged near the plate surface on the other side in the thickness direction of the container 8 (on the left side in FIGS. 3 and 4), while the unfolded surface of the frame body 11 faces the plate surface of the container 8, and the second The ends of the pair of wire rods 13a in the frame portion 13 are held at the corners inside the container 8, and the plate surface state of the container 8 is maintained by the second frame portion 13. As shown in FIG. The airbag 9 is made of a material having stretchability and flexibility (for example, thermally conductive filler (alumina, boron nitride, etc.) containing plastic (polyurethane, etc.), rubber-based resin (EPDM, etc.)). The airbag 9 is formed as a flat bag corresponding to the rectangular shape of the frame portion 12 . 8 is held on one side in the thickness direction (battery 2 side). Therefore, when air (gas) is supplied into the airbag 9, as shown in FIG. While maintaining this, it expands in the direction of abutting on the inner plate surface on one side in the thickness direction of the container 8 .

The phase change material 10 undergoes a phase change between a solid phase and a liquid phase. As the phase change material 10, one whose phase transition temperature (constant) is within the proper temperature range (upper and lower limit range) of the battery 2 is used (when the battery 2 is a lithium ion battery, it is 25° C. to 60° C.), specifically, paraffin-based hydrocarbons, transition metal-based ceramics, and the like are used.

The housing 5 includes, as shown in FIG. 2, a box body 14 with an upper opening and an upper lid 15 covering the opening of the box body 14 . The box main body 14 accommodates therein the aforementioned battery 2 and the cooling unit 4 (accommodating container 8) to be brought into contact with the constituent surface thereof. is sandwiched between the battery 2 and the box body 14 . The upper lid 15 covers the upper opening of the box body 14 with the battery 2 and the plurality of cooling units 4 housed therein. The housing 5 is provided with a cooling path 16 for flowing cooling liquid. The cooling path 16 is to pass through each component plate of the box body 14 along its configuration surface for cooling the phase change material 10 in each cooling unit 4. In order to form this cooling channel, the box The main body 14 is provided with flow passages, and cooling pipes are attached to the box main body 14 . In order to clarify the existence of the cooling path 16, FIG. 2 shows a state in which the cooling pipes forming the cooling path 16 are attached to the box body 14. As shown in FIG. When it is determined that the solid phase is insufficient in the liquid-solid equilibrium state of the phase change material 10, cooling liquid is flowed through the cooling path 16 in order to increase the relative proportion of the solid phase. , the phase change material 10 of each cooling unit 4 is cooled by the coolant.

As shown in FIGS. 1, 3, and 4, the air supply device 6 includes an air supply pipe 17 forming an air supply passage as a gas supply passage, and an air pump 18 as a gas supply section. . One end of the air supply pipe 17 opens into the airbag 9 and the other end extends out of the container 8 . The air pump 18 is connected to the other end of the air supply pipe 17 , and the air as gas is supplied into the airbag 9 by driving the air pump 18 .

As shown in FIGS. 1, 3, and 4, the air discharge device 7 includes a discharge pipe 19 forming a discharge passage and an on-off valve (solenoid valve) 20 interposed in the discharge pipe 19. ing. One end of the discharge pipe 19 is opened inside the airbag 9 and the other end is connected to an intake manifold 22 of the engine 21 . The on-off valve 20 determines whether or not the inside of the airbag 9 and the inside of the intake manifold 22 are to be communicated with each other.

A container for each cooling unit 4 is provided with a vibration propagation measurement unit 23, which is one component of the liquid-solid equilibrium detector. This vibration propagation measurement unit 23 includes an oscillation source that oscillates vibration toward the phase change material 10 in the container 8 having a certain length, and a reflected vibration detection that detects arrival of reflected vibration of the vibration from the oscillation source. and a sensor, both of which determine the vibration return time for a given vibration travel distance.

The cooling system 1, as shown in FIG. 1, includes a control unit U as a control section for controlling the air pump 18 and the on-off valve 20. As shown in FIG. Therefore, control signals are output from the control unit U to the air pump 18 and the on-off valve 20, while the control unit U receives ON/OFF signals from the ignition switch 24 and an outside air temperature sensor 25 as an ambient temperature acquisition unit. Temperature information and battery temperature information from the battery temperature sensor 26 are input.

The control unit U is provided with a storage section 27 and an arithmetic control section 28 as shown in FIG. 7 in order to ensure functions as a computer. The storage unit 27 includes storage elements such as ROM (Read Only Memory) and RAM (Random Access Memory). Also, the vibration propagation speed (set first vibration propagation speed) when there is a solid phase to some extent, and the liquid phase is slightly higher than the state where the phase change material 10 is all in the solid phase Vibration propagation speed (set second vibration propagation speed), set outside air temperature (predetermined value), first injection amount V1 of air into the airbag 9, second injection amount V2 of air into the airbag 9 (V1> V2), the predetermined opening time of the on-off valve 20 is stored. In addition to the basic program, various necessary programs include a program for determining whether or not the ignition switch 24 is ON, a component of the liquid-solid equilibrium state detection unit based on the vibration return time measured by the vibration propagation measurement unit 23. , which calculates the vibration propagation velocity in the phase change material 10 (vibration propagation velocity calculation), and whether or not the calculated vibration propagation velocity is greater than the set first vibration propagation velocity and smaller than the set second vibration propagation velocity Determines whether or not the liquid-solid equilibrium state is established by determining the state of liquid-solid equilibrium (liquid-solid equilibrium state determination), determines whether the outside temperature is less than the set outside temperature (predetermined value) (outside temperature condition determination), battery temperature The storage unit 27 stores data for determining whether or not the temperature is in a rising state (temperature rising state determination).

The arithmetic control unit 28 is configured with a CPU (Central Processing Unit), and based on a program read from the storage unit 27, the arithmetic control unit 28 operates as shown in FIG. It functions as a vibration propagation velocity calculation unit 28b, a liquid-solid equilibrium state (liquid-solid coexistence state) determination unit 28c, an outside air temperature condition determination unit 28d, a temperature rise state determination unit 28e, and the like.

Such a cooling system 1 generally performs the following control.

(1) In this cooling system 1, even when the storage container 8 of each cooling unit 4 is in contact with each component surface of the battery 2, when the battery 2 does not need to be cooled, the phase change material in each cooling unit 4 The heat absorption efficiency of the heat of the battery 2 by 10 is reduced to suppress the temperature drop of the battery 2 .

(2) For this reason, first, in order to determine when the battery 2 does not need to be cooled, the determination condition is whether the vehicle is parked and the outside air temperature is less than a predetermined value (set outside air temperature). be discriminated. A container 8 containing a phase change material 10 is arranged in contact with the surface constituting the battery, and the phase change material 10 absorbs heat if there is a temperature difference between the phase change material 10 and the battery. However, even when it is desired to maintain the battery 2 in a heat-retaining state, such as during parking in winter, the battery 2 is quickly cooled down to about the outside temperature. In the upper diagram of FIG. 8, the dashed battery temperature characteristic line (without airbag) indicates the above situation. In this case, the OFF state of the ignition switch 24 is used to determine that the vehicle is parked. , are determined by the IG-ON determination unit 28A and the outside air temperature condition determination unit 28d, respectively.

(3) It is also determined whether the phase change material 10 is in a liquid-solid equilibrium state (liquid-solid coexistence state). If at least the liquid phase does not exist in the phase change material 10, when the battery 2 does not need to be cooled, the expansion and deployment of the airbag 9 causes the airbag 9 and the storage container 8 to move in one direction in the thickness direction, as will be described later. This is because the solid phase portion in the phase change material 10 between the side inner plate surface and the liquid phase portion cannot be pushed aside. Therefore, in the present embodiment, the vibration propagation velocity V in the current phase change material 10 calculated by the vibration propagation velocity calculator 28b is the set first vibration propagation velocity (the phase change material 10 is all close to the liquid phase). state) and smaller than the set second vibration propagation speed (vibration propagation speed when all the phase-change material 10 is in a state close to the solid phase). (Liquid-solid coexistence state) Judgment is made by the judging section 28c. Of course, on the other hand, based on the information from the vibration propagation velocity calculation unit 28b or the information from the liquid-solid equilibrium state (liquid-solid coexistence state) determination unit 28c, the cooling liquid flowing through the cooling path 16 in the housing 5 (box body) is It is adjusted so that the phase change material 10 is maintained in a liquid-solid equilibrium state (liquid-solid coexistence state).

(4) It is determined that the vehicle is parked, the outside air temperature is below a predetermined value (set outside air temperature), and the phase change material 10 in each cooling unit 4 is in a liquid-solid equilibrium state (liquid-solid coexistence state). When it is determined that there is, as shown in FIG. 8, the air pump 18 is driven for a predetermined period of time to inject air into the airbag 9 by the first injection amount V1. As a result, air as gas is supplied into the airbag 9, and the airbag 9 receives the reaction force of the frame body 11 as shown in FIG. , expands in the direction of contact with the inner plate surface on one side in the thickness direction of the container 8 . As a result, the solid phase portion in the phase change material 10 between the airbag 9 and the inner plate surface on one side in the thickness direction of the container 8 is pushed away by the airbag 9 together with the liquid phase portion. The heat absorption efficiency of the battery heat by the change material 10 can be reduced, and the temperature drop of the battery 2 can be suppressed even if the container 8 containing the phase change material 10 is in contact with the surface constituting the battery. In addition, the air in the airbag 9 forms an air layer between the surrounding atmosphere of the battery 2 and the battery 2, and the temperature drop of the battery 2 can be effectively suppressed by the heat insulating effect. Become. As a result, as shown by the solid line in FIG. 8, the temperature of the battery 2 can be kept higher than when the airbag 9 is not used (see the broken line in FIG. 8) even during parking in winter. can be done. In this case, as the first injection amount V1 of air, an amount of air is set in consideration of the contact of the airbag 9 with the inner plate surface on one side in the thickness direction of the container 8 .

In this case, when the temperature of the battery 2 is high, the amount of air injected into the airbag is reduced to the second injection amount V2 by shortening the driving time of the air pump 18 in FIG. (V1>V2). This is because the temperature of the battery 2 is raised due to charging or the like. This is because, even when the vehicle is parked, as long as the temperature of the battery 2 is in an elevated state, it is necessary to prevent the temperature of the battery from rising above the allowable upper temperature limit. In this case, in the present embodiment, the space between the airbag 9 and the inner plate surface on one side in the thickness direction of the container 8 is narrowed by the second injection amount V2. As a result, the narrowed gap between the airbag 9 and the inner plate surface on the one side in the thickness direction of the container 8 is in contact with the inner plate surface on the one side in the thickness direction of the container 8 . , the heat exchange with the phase change material 10 existing at a location distant from the inner plate surface on one side in the thickness direction of the container is delayed, and at that time, the heat absorption effect of the phase change material 10 with respect to the battery 2 exists. However, compared to the case where the airbag 9 and the inner plate surface on one side in the thickness direction of the container 8 are in contact with each other, the heat absorbing effect of the phase change material 10 on the battery 2 is reduced.

(5) When the ignition is turned on and the engine 21 is started, the on-off valve 20 is opened for a predetermined time as shown in FIG. Then, the inside of the intake manifold 22 becomes a negative pressure (less than the atmospheric pressure), and the negative pressure (less than the atmospheric pressure) inside the intake manifold 22 at the start of the engine 21 is used to capture the precise timing of starting the engine 21, and the air is released. This is for extracting the air inside the bag 9 . This eliminates the need for special measures such as reverse rotation of the air pump 18 .

The details of the control of the cooling system 1 will be specifically described according to the flow chart (where Q indicates a step) shown in FIG.

When the process starts, first, in Q1, the ON/OFF signal from the ignition switch 24, the outside air temperature information from the outside air temperature sensor 25, the temperature information of the battery 2 from the battery temperature sensor 26, and the like are acquired. In the next Q2, it is determined whether or not the ignition switch 24 is ON. This is for determining whether or not the vehicle is parked. When Q2 is NO, it is determined whether or not the phase change material 10 in each cooling unit 4 is in a liquid-solid equilibrium state (liquid-solid coexistence state). This is to determine whether or not the airbag 9 can be inflated and deployed (by pushing away the phase change material between the airbag 9 and the inner plate surface on one side in the thickness direction of the container 8). When this Q3 is NO, the process proceeds to Q5, in which the air pump 18 is put into a non-operating state (the airbag 9 is not inflated and deployed). is less than a predetermined temperature (set outside air temperature). This is for determining whether or not it is in an outside air temperature state such as in winter. When Q4 is NO, the process proceeds to Q5. When Q4 is YES, it is determined in the next Q6 whether or not the temperature of the battery 2 is rising. This is to prevent the temperature of the battery 2 from rising above the allowable upper limit temperature due to charging of the battery 2 or the like while the vehicle is parked.

Therefore, when Q6 is NO, it is not necessary to consider the temperature rise of the battery 2. Therefore, in Q7, the amount of air to be injected into the airbag 9 is set as the basic first injection amount V1, and Q8, In Q9, the air pump 18 is operated for a drive time corresponding to the first injection amount V1 of air in Q7. Then, when the first injection amount of air is injected into the airbag 9 (Q9YES), the air pump 18 is stopped (Q10). As a result, the airbag 9 is inflated and deployed in a direction in which it abuts against the inner plate surface on one side in the thickness direction of the container 8 . The solid phase portion in the phase change material 10 between the inner plate surface on one side in the thickness direction is pushed away together with the liquid phase portion. As a result, even if the inner plate surface on one side in the thickness direction of the container 8 is in contact with the structural surface of the battery 2, the heat absorption efficiency of the battery heat by the phase change material 10 can be reduced. Even when the vehicle is parked, it is possible to prevent the battery 2 from being cooled down to about the outside temperature in an early stage.

When Q6 is YES, the amount of air to be injected into the airbag 9 is set to a second injection amount V2 smaller than the first injection amount V1 in Q11 in consideration of the temperature rise of the battery 2 . When the amount of air injected into the airbag 9 is set to the first injection amount V1, the heat absorption effect on the battery 2 is not reduced, but the temperature of the battery 2 is prevented from rising to the allowable upper limit temperature or higher. This is because it is necessary to consider preventing it.

When Q2 is NO, the on-off valve 20 is opened for a predetermined time in Q12. This is because the negative pressure in the intake manifold 22 is utilized and the air in the airbag 9 is extracted at the exact timing of starting the engine 21 without any special measures or treatments. After this, it is returned.

Although the embodiments have been described above, the present invention includes the following aspects.
(1) Using the cooling system 1 to cool a battery other than the battery mounted on the vehicle.
(2) Arrange the battery 2 in a place other than the engine room, such as a trunk room.
(3) Use the phase transition temperature (constant temperature) of the phase change material 10 to detect the liquid-solid equilibrium state (liquid-solid coexistence state).
(4) An on-off valve is provided in the air supply pipe 17 between the cooling unit 4 and the air pump 18, and the amount of air supplied to the airbag 9 is adjusted by adjusting the opening time of the on-off valve.

The present invention can be used to suppress heat absorption by the phase change material 10 to the battery 2 without moving the storage container 8 of the phase change material 10 when the battery does not need to be cooled.

REFERENCE SIGNS LIST 1 cooling system 2 battery 4 cooling unit 8 container 9 airbag 10 phase change material 17 air supply pipe (gas supply path)
18 Air pump (gas supply unit)
19 discharge pipe (discharge channel)
20 on-off valve 21 engine 22 intake manifold 23 vibration propagation measurement unit (liquid-solid equilibrium state (liquid-solid coexistence) detector)
24 ignition switch (parking detector)
25 outside air temperature sensor (surrounding temperature acquisition unit)
26 Battery temperature sensor (battery temperature detector)
28b Vibration propagation velocity calculation unit (liquid-solid equilibrium state (liquid-solid coexistence) detection unit, control unit)
U control unit (control part)

Claims (5)

A battery cooling system,
a container that abuts against the surface of the battery;
an airbag disposed within the container;
a phase-change material that is housed in the storage container between the storage container and the airbag and that changes phases between a solid phase and a liquid phase;
a gas supply passage having one end open in the airbag and the other end extending outside the airbag;
a gas supply unit connected to the other end of the gas supply path and supplying gas toward the inside of the airbag;
a liquid-solid equilibrium detection unit that detects the liquid-solid equilibrium state of the phase change material;
an ambient temperature acquisition unit that acquires the ambient temperature of the battery;
It is determined that the phase-change material is in a liquid-solid equilibrium state based on the detection information from the liquid-solid equilibrium state detection unit, and based on the ambient temperature acquired from the ambient temperature acquisition unit, the ambient temperature is higher than a predetermined temperature. a control unit that controls the gas supply unit to increase the amount of gas supplied to the inside of the airbag when it is determined that the ambient temperature is lower than that when the ambient temperature is equal to or higher than the predetermined temperature;
is equipped with
A battery cooling system characterized by: In claim 1,
The airbag is installed in the storage container so as to extend along the surface of the battery with which the storage container abuts.
A battery cooling system characterized by: In claim 1 or 2,
The battery is disposed in a vehicle,
Having a parking detection unit that detects that the vehicle is parked,
The control unit is set to allow execution of the heat retention control when it is determined that the vehicle is parked based on detection information from the parking detection unit.
A battery cooling system characterized by: In any one of claims 1 to 3,
The battery is disposed in a vehicle equipped with an engine,
The inside of the airbag is connected to an intake manifold of the engine through an exhaust passage having an on-off valve,
The control unit is set to open the on-off valve only during a predetermined period when an IG-ON signal is received from the ignition switch.
A battery cooling system characterized by: In claim 1 or 2,
The battery is disposed in a vehicle,
A parking detection unit that detects that the vehicle is parked, and a battery temperature detection unit that detects the temperature of the battery,
The control unit determines that the vehicle is parked based on detection information from the parking detection unit during execution of the heat retention control, and the temperature of the battery rises based on temperature information from the battery temperature detection unit. is set to reduce the amount of gas supplied to the inside of the airbag when it is determined that the state is present, compared to when the heat retention control is being performed
A battery cooling system characterized by:

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