JPH11307139A - Battery cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery cooling device that can uniformly cool multiple batteries without irregularity, can exert a battery temperature rise restraining effect even when parking under the blazing sun, and has high degree of freedom of installation place selection. SOLUTION: A silicone oil 16 having an electrical insulation property is filled in the inside of a sealed container 10 to receive multiple batteries 14, and a coolant pipe arrangement 15 to cool the silicone oil 16 is installed in the sealed container 10. Thereby, the batteries 14 can be cooled through the silicone oil 16 cooled by the coolant pipe arrangement 15. Since the silicone oil 16 is liquid, it can uniformly come into direct contact with the entire outside surfaces of the batteries 14, so that the entire outside surfaces of the multiple batteries 14 can uniformly be cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric vehicle (EV)
And a cooling device for a battery mounted on a hybrid vehicle (HV) or the like.

[0002]

2. Description of the Related Art A battery mounted on a vehicle such as an electric vehicle or a hybrid vehicle is used as a power source for an electric motor for driving the vehicle, and therefore needs to have a high voltage and a large capacity. Therefore, an assembled battery in which a plurality of batteries are electrically connected in series is generally used. By the way, in this assembled battery, heat is generated due to chemical reaction and Joule loss in each battery during charging and discharging,
The temperature of the battery rises, adversely affecting the performance and life of the battery. Therefore, various cooling devices for cooling the battery have been conventionally proposed.

For example, Japanese Patent Laying-Open No. 5-169981 proposes a device for cooling a battery by taking in outside air. Further, Japanese Patent Application Laid-Open No. 5-262144 proposes a device for cooling a battery by taking in conditioned air whose temperature has been adjusted by an air conditioner in a vehicle compartment. Further, Japanese Patent Application Laid-Open
According to Japanese Patent No. 6796, the battery is housed in a space defined by a side wall and a partition plate of a bottom plate of a battery case, and a refrigerant pipe through which a low-temperature refrigerant flows is embedded in the bottom plate and the partition plate of the battery case. A battery that cools a battery by the cold heat of the battery has been proposed.

[0004]

However, in the former disclosed in Japanese Patent Application Laid-Open No. H5-169981, since the cooling medium is the outside air, the cooling performance of the battery is significantly reduced at high temperatures such as in summer. In addition, since air cooling is used, it is practically difficult to uniformly blow cooling air to a large number of batteries, and variations in the cooling effect of the batteries and temperature unevenness are likely to occur.

[0005] Further, since the device disclosed in Japanese Patent Application Laid-Open No. 5-262144 is air-cooled, variations in the cooling effect of the battery and temperature unevenness are likely to occur. In addition, since air-conditioned air from the air conditioner in the passenger compartment is taken in, it is necessary to connect the air conditioner and the battery cooling device with an air duct, and the installation location of the battery cooling device is restricted by the relationship with the air conditioner. As a result, there is a problem that the degree of freedom in selecting the installation location is reduced.

Further, in Japanese Unexamined Patent Publication No. 7-6796, heat is absorbed from the battery via the bottom plate, partition plate and the like of the battery case due to the cooling heat of the refrigerant pipe. Is easy to occur. Also, JP-A-5-262144 and JP-A-7-6
In any of the devices disclosed in Japanese Patent Application Publication No. 796, the cooling effect is lost by stopping the operation of the vehicle air conditioner, so that the temperature of the battery rises significantly during parking under the scorching sun in summer.

[0007] The present invention has been made in view of the above points,
While being able to cool multiple batteries evenly and evenly,
Even when parking under the hot weather, it can demonstrate the effect of suppressing the rise in battery temperature,
Moreover, an object of the present invention is to provide a battery cooling device having a high degree of freedom in selecting an installation location.

[0008]

In order to achieve the above-mentioned object, according to the first to sixth aspects of the present invention, an electrically insulating cooling liquid (16) is provided in a sealed container (10) containing a battery (14). ), And a cooling pipe (15) through which a cooling medium for cooling the cooling liquid (16) flows is disposed in the closed container (10).

According to this, the battery (14) can be cooled via the cooling liquid (16) cooled by the cooling pipe (15). Since the cooling liquid (16) is a liquid, it can uniformly and directly contact the entire outer surface of the battery (14),
Therefore, it is possible to uniformly cool the entire outer surfaces of the plurality of batteries (14). In addition, since the cooling liquid (16) is forcibly cooled to a low temperature by the cooling pipe (15) even at a high temperature such as in summer, the cooling capacity of the battery (14) is not affected by the fluctuation of the outside air temperature. Can be exhibited stably.

Further, since the cooling pipe (15) can be constituted by a small-diameter pipe through which the cooling medium flows, the piping can be easily arranged as compared with the air duct, and therefore, the location for installing the battery cooling device can be selected. The degree of freedom is increased, and this is practically very advantageous in applications such as vehicles where space constraints are large. Further, since the battery (14) is cooled via a liquid (cooling liquid) having a specific heat greater than that of the gas, the cooling liquid (1) is cooled.
Due to the cold storage action (sensible heat) according to 6), the low temperature state of the battery (14) can be maintained even after the cooling action of the cooling pipe (15) is stopped. Therefore, even when the vehicle is parked under the scorching sun, it is possible to suppress a rise in the temperature of the battery (14).

The present invention specifically relates to claim 2
As described in the above, the battery (14) is disposed in the closed container (10) such that the longitudinal direction of the battery is oriented in the horizontal direction, and the cooling pipe (15) is horizontally arranged so as to surround the periphery of the battery (14). It may be configured to be arranged to extend. According to the third aspect of the present invention, if the overall shape of the sealed container (10) is flat, the height of the entire battery cooling device is small, so that the space inside the space having a small height such as under the floor of a vehicle is provided. It is possible to mount a battery cooling device on the vehicle.

According to the fourth aspect of the present invention, the convection means (24, 24) forcibly convection the cooling liquid into the closed vessel (10).
25), the temperature distribution of the cooling liquid becomes uniform,
The battery (14) can be cooled more uniformly. As described in claim 5, the cooling liquid can be constituted specifically by a silicone oil (16).

[0013] Further, as described in claim 6, the cooling pipe is
Specifically, it can be constituted by a refrigerant pipe (15) through which the refrigerant on the low pressure side of the refrigeration cycle flows. In addition, the code | symbol in the parenthesis of each said means shows the correspondence with the concrete means of embodiment mentioned later.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 and 2 show a first embodiment. A closed container 10 has a rectangular parallelepiped shape as shown in FIG. 1, and has a container body 11 and an upper open end of the container body 11. And an upper lid 12 that closes the cover. Here, the container main body 11 and the upper lid 12 are formed of a heat insulating material, for example, a resin material, and are detachably connected by an appropriate fastening means. Note that the container body 11 and the upper lid 12 may be formed of a metal material, and a heat insulating material may be attached to the surfaces thereof.

A plurality of (four in this example) resin or metal support plates 13 are vertically arranged at regular intervals inside the container body 11 and fixed to the bottom of the container body 11. The support plate 13 has a circular through hole 13a for disposing the cylindrical battery 14 in the horizontal direction. Here, as shown in FIG. 1 (b), a total of 21 through holes 13a for the battery are provided, and by providing an interval between the through holes 13a, the through holes 13a between the outer peripheral sides of the cylindrical batteries 14 are provided. Are spaced.

Note that the cylindrical battery 14 is
In the left-right direction, two batteries are arranged in series, and a partition line A shown in FIG. 1B indicates the dividing position. In this example, the total number of the batteries 14 is 21 × 2 = 42, and they are electrically connected in series. Each battery 14 is a rechargeable secondary battery (storage battery), for example, a nickel-metal hydride battery. If the nickel-metal hydride battery is appropriately cooled and the temperature of the battery does not become high, the gas generated inside the battery is Has the basic characteristics of absorbing the gas inside the battery and maintaining the internal pressure at the atmospheric pressure level.

A refrigerant pipe (cooling pipe) 15 is provided inside the sealed container 10 so as to surround the outer peripheral side of each battery 14.
Are arranged to extend in the horizontal direction. This refrigerant pipe 15 is for the flow of a low-temperature refrigerant (cooling medium) of a refrigeration cycle for vehicle air conditioning, and has a meandering one refrigerant flow path between an inlet pipe 15a and an outlet pipe 15b taken out above the upper lid 12. Is formed. U-shaped connection pipes 15c of the refrigerant pipes 15 are arranged on both left and right sides in the closed container 10. The support plate 13 has a circular through hole 13 for horizontally inserting the refrigerant pipe 15 around the battery through hole 13a.
Many b are open.

Further, the interior of the sealed container 10 is filled with a silicone oil 16 as a cooling liquid having an electrical insulation property. The refrigerant pipe 15 is made of a metal such as aluminum having excellent heat conductivity and corrosion resistance, and has a plate-like heat transfer fin for facilitating transfer of heat with the silicone oil 16 on the outer peripheral surface of the refrigerant pipe 15. May be provided. Further, a gas discharge pipe 17 is provided in the upper lid 12 of the sealed container 10, and this gas discharge pipe 17 is for discharging hydrogen gas generated from the battery 14 to the outside of the container when the temperature of the battery 14 is high. The gas discharge pipe 17 is provided with a relief valve 18 that opens when the pressure in the sealed container 10 rises to a predetermined pressure. Each battery 14 also has a relief valve (not shown) for discharging hydrogen gas to the outside.

FIG. 2 is a refrigeration cycle diagram for vehicle air conditioning. Reference numeral 19 denotes a compressor that compresses and discharges refrigerant, reference numeral 20 denotes a condenser that cools and condenses refrigerant discharged from the compressor 19,
Reference numeral 1 denotes a receiver for separating gas-liquid of the condensed refrigerant from the condenser 20 and stores the liquid refrigerant, and 22 decompresses the liquid refrigerant from the receiver 21 and expands it into a low-temperature low-pressure gas-liquid two-phase state. The pressure reducing means is, for example, a temperature-type expansion valve.

Reference numeral 23 denotes an evaporator for absorbing the heat of the gas-liquid two-phase refrigerant from the decompression means 22 from the conditioned air to evaporate. The refrigerant pipe 15 in the closed container 10 is connected to the evaporator 2.
3, and a gas-liquid two-phase refrigerant from the decompression means 22 passes therethrough. Next, the operation of the first embodiment in the above configuration will be described. By operating the compressor 19 in the refrigeration cycle for vehicle air conditioning, the refrigerant circulates in the refrigeration cycle in FIG. Thus, the evaporator 23 absorbs latent heat of evaporation from the conditioned air to evaporate the refrigerant, thereby cooling the conditioned air and cooling the passenger compartment.

On the other hand, in the battery cooling device, the refrigerant in the refrigerant pipe 15 absorbs latent heat of evaporation from the silicon oil 16 in the closed vessel 10 and evaporates, thereby cooling the silicon oil 16. Here, in a refrigeration cycle for vehicle air conditioning, since the evaporation temperature of the normal refrigerant is around 0 ° C., the silicon oil 16 is charged under normal operating conditions of the vehicle.
Can be cooled to a low temperature of 10 ° C. or less.

Moreover, the silicone oil 16 is supplied to the closed container 1
Since the cells 0 are filled with the liquid in a full state, and there is a space between the batteries 14, the silicon oil 16 can uniformly and directly contact the entire outer surface of each battery 14. As a result, a large number of batteries 14 can be uniformly cooled by the silicon oil 16 maintained at a low temperature without unevenness in temperature. Moreover, since the silicon oil 16 is a liquid having a higher specific heat than a gas, and the liquid is cooled to a low temperature, the cooling capacity for the battery 14 can be increased, and
Natural convection occurs in the vertical direction due to the temperature difference of the silicone oil 16 inside the closed container 10, and the silicone oil 1
6 and the outer surface of each battery 14 can be facilitated.

Further, since the silicon oil 16 has an electrical insulation property, it is possible to prevent problems such as an electric short circuit between the batteries 14 and a current leakage. In addition, when parking the vehicle,
Normally, the drive source (vehicle engine or electric motor) of the compressor 19 is stopped, so that the refrigeration cycle for vehicle air conditioning is also stopped. Therefore, the cooling action by the refrigerant pipe 15 in the closed container 10 is also stopped, but since the silicon oil 16 is liquid and has a large specific heat, the cooling action of the silicone oil 16 (sensible heat) causes the cooling of each battery 14 even after parking. Can maintain a low temperature condition.

When the temperature of the battery 14 is high, the battery 1
When the amount of hydrogen gas generated from the fuel gas 4 is small, the hydrogen gas is dissolved in the silicon oil 16.
It cannot be dissolved therein, and comes to exist in the closed container 10 as a gas. As a result, when the pressure in the closed vessel 10 rises to a predetermined pressure, the relief valve 18 of the gas discharge pipe 17 opens, and the hydrogen gas in the closed vessel 10 is discharged to the outside through the gas discharge pipe 17. .

Further, compared to a type that requires an air introduction duct, such as a type that introduces cool air from an air conditioner, the degree of freedom of piping management of the refrigerant pipe 15 of the battery cooling device according to the present embodiment is higher. In a vehicle with a large space restriction, the degree of freedom in selecting the installation location of the battery cooling device can be increased, which is extremely advantageous in practice. (Second Embodiment) FIG. 3 shows a second embodiment, in which an impeller 25 driven by a motor 24 is added to the inside of the sealed container 10 as compared with the first embodiment. The difference is that the silicone oil 16 is forcedly convected.

According to this, the amount of heat transfer between the silicon oil 16 and the outer surface of each battery 14 can be increased by the forced convection of the silicon oil 16, and the battery cooling effect can be improved.
In addition, since the silicon oil 16 has an electrical insulation property, the motor 24 can be arranged in the sealed container 10 together with the impeller 25. Therefore, the motor 24 can also be cooled by the silicon oil 16.

Further, when the motor 24 is arranged outside the sealed container 10, it is necessary to arrange the rotating shaft through the wall surface of the sealed container 10, so that the silicon oil 16 leaks from around the rotating shaft. Although it is easy, according to the second embodiment, there is no fear of such a problem. (Third Embodiment) FIG. 4 shows a third embodiment in which the overall shape of the sealed container 10 is flattened compared to the first and second embodiments. That is, the overall shape of the closed container 10 is smaller than the vertical and horizontal dimensions of the planar shape shown in FIG.
The flat shape in which the height dimension (vertical dimension) shown in FIGS. 4B and 4C is sufficiently reduced is adopted.

According to the third embodiment, since the entire shape of the closed container 10 is flat, the closed container 10 can be mounted in a space having a small height such as under the floor of a vehicle. Further, since the height of the closed container 10 is very small, the temperature distribution in the height direction inside the closed container 10 can be extremely reduced.

[Brief description of the drawings]

FIG. 1A is a plan sectional view of a first embodiment of the present invention,
(B) is a left side sectional view of the first embodiment, and (c) is a front sectional view of the first embodiment.

FIG. 2 is a refrigeration cycle diagram of the first embodiment.

FIG. 3A is a plan sectional view of a second embodiment of the present invention,
(B) is a left side sectional view of the second embodiment, and (c) is a front sectional view of the second embodiment.

FIG. 4A is a plan sectional view of a third embodiment of the present invention,
(B) is a sectional view taken along line DD of (c), and (c) is a sectional view taken along line C- of (a).
It is C sectional drawing.

[Explanation of symbols]

10 ... closed container, 14 ... battery, 15 ... refrigerant piping, 16 ...
Silicon oil (coolant).

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yuichi Sakagami 14 Iwatani, Shimowakaku-cho, Nishio-shi, Aichi Japan Inside Automobile Research Institute, Inc. (72) Inventor Jun Okuda, Toyota Town, Toyota City, Aichi Prefecture 1 Toyota Motor Corporation (72) Inventor Kan Fukuda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (6)

[Claims] An airtight container (1) containing a battery (14).
0) The inside is filled with a cooling liquid (16) having electrical insulation properties, and a cooling pipe (15) through which a cooling medium for cooling the cooling liquid (16) flows is arranged in the closed container (10). A battery cooling device, comprising: 2. The battery (14) is connected to the closed container (1).
The cooling pipe (15) is disposed so as to extend in the horizontal direction so as to surround the periphery of the battery (14). The battery cooling device according to claim 1. 3. The battery cooling device according to claim 1, wherein the entire shape of the closed container (10) is flat. 4. The battery cooling device according to claim 1, wherein a convection means (24, 25) for forcibly convection the cooling liquid is arranged in the closed container (10). apparatus. 5. The battery cooling device according to claim 1, wherein the cooling liquid is a silicone oil (16). 6. The battery cooling device according to claim 1, wherein the cooling pipe is a refrigerant pipe through which a refrigerant on a low pressure side of a refrigeration cycle flows.