JP6451604B2 - Battery cooling system - Google Patents

Description

  The present invention relates to a battery cooling system.

  Conventionally, in electric vehicles and hybrid vehicles, rotating electrical machines have been used as vehicle drive sources. A battery pack is mounted on the vehicle as a power source for the rotating electrical machine. The battery pack includes a battery stack (module) in which a plurality of battery modules are stacked and connected in series, and a case that houses the battery stack. The battery stack and the battery pack have a substantially rectangular parallelepiped shape in which the stacking direction of the battery modules is the longitudinal direction.

  The battery stack is cooled by a cooling device. For example, Patent Document 1 discloses a cooling device for a vehicle battery housed in a housing space together with a battery pack housing a battery body housed in a battery case, and a blower, an intake duct, and a branch branched from the intake duct A cooling device that includes a duct and cools a battery and ventilates and cools an accommodation space is described.

  In the battery stack, a gap is provided between adjacent battery modules. One end of this gap communicates with the intake chamber, the other end communicates with the exhaust chamber, and cooling air flows through this gap as the cooling passage 18, thereby lowering the temperature of the battery module.

JP2015-48009A

  By the way, in the air-cooled battery pack, there are roughly two types of methods for flowing cooling air through the battery stack, based on the positional relationship between the intake port of the intake chamber and the exhaust port of the exhaust chamber. In a method called a Z-turn system, the surface of the battery pack provided with the air inlet is opposed to the surface of the battery pack provided with the exhaust port. In a method called a U-turn system, an air inlet and an air outlet are provided on the same side surface of the battery pack.

  In the Z-turn system, since the intake and exhaust ports are provided on the opposite surfaces of the battery pack, compared to the U-turn system, the degree of freedom in arranging parts such as ducts and blowers is high, and the battery pack and cooling There is an advantage that a compact arrangement of an apparatus or the like is possible. On the other hand, in the Z-turn method, the amount of cooling air flowing inside the battery stack is biased in the stacking direction of the battery modules due to the direction of the cooling air, and the temperature distribution inside the battery stack may vary.

The present invention provides a battery stack in which a plurality of battery modules are stacked and a cooling passage through which cooling air passes is provided between the battery modules, a case for housing the battery stack, and an intake air extending in the stacking direction. A chamber and an exhaust chamber extending in the stacking direction , wherein the intake chamber and the exhaust chamber are disposed so as to sandwich the battery stack, and each of the intake chamber and the exhaust chamber is disposed at both ends of the cooling passage. A battery cooling system comprising a battery pack and a blower for supplying cooling air to the intake chamber, wherein an intake port through which the cooling air flows into the intake chamber is a first of the battery pack. The exhaust port through which the cooling air flows out of the exhaust chamber is provided on the second surface facing the first surface of the battery pack. Vignetting, the first surface and the second surface, either be a surface intersecting the axis which is the stacking direction of the battery module, wherein the exhaust chamber, cooling air of the case from the exhaust chamber A plurality of ventilation portions that flow out to the outside are provided, and the ventilation portions are arranged between the battery modules, and form a row along the stacking direction of the battery modules.

  According to the present invention, in the Z-turn type battery pack in which the air inlet and the air outlet are provided on the opposite surfaces of the battery pack, a part of the cooling air in the exhaust chamber is caused to flow out from the ventilation portion to By reducing the pressure, it is possible to alleviate the unevenness in the stacking direction of the battery modules in the amount of cooling air flowing inside the battery stack and to make the temperature distribution inside the battery stack uniform.

It is a figure which shows an example of the battery cooling system which concerns on this embodiment. It is a figure which shows an example of the battery pack which comprises the battery cooling system which concerns on this embodiment. It is a figure which shows an example of the member used for the case which comprises the battery cooling system which concerns on this embodiment. It is a figure which shows an example of the conventional battery cooling system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a battery cooling system 10 (hereinafter also simply referred to as “cooling system 10”) according to the present embodiment. The cooling system 10 according to the present embodiment includes a battery pack 12 to be cooled and a blower 50. The battery pack 12 includes a battery stack 14, a case 20 that houses the battery stack 14, an intake chamber 22, and an exhaust chamber 26. 1 to 4, the x axis is defined in the stacking direction of the battery modules 16 (longitudinal direction of the battery stack 14), the z axis is defined in the gravity direction, and the y axis is defined as the x axis and the z axis, respectively. Specified in the orthogonal direction.

  The cooling system 10 is disposed in an accommodation space formed under a vehicle cabin or a cargo compartment. The accommodation space is formed under an interior member of the vehicle, such as a seat, console, floor case, floor carpet, or deck case provided on the floor of the luggage compartment, for example.

  The battery stack 14 is formed in a substantially rectangular parallelepiped shape in which a plurality of battery modules 16 are stacked, and the stacking direction of the battery modules 16 coincides with the longitudinal direction of the battery stack 14. The plurality of battery modules 16 are electrically connected in series by, for example, a bus bar or the like. The battery module 16 has a plate-like substantially rectangular parallelepiped shape. A spacer (not shown) or the like is disposed between adjacent battery modules 16, and a gap between the battery modules 16 provided thereby becomes a cooling passage 18 through which cooling air passes. The cooling passage 18 may be tubular, for example. The battery module 16 may be a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

  The case 20 accommodates the battery stack 14 so as to cover the entire battery stack 14. The intake chamber 22 and the exhaust chamber 26 are formed as a space adjacent to the battery stack 14 and surrounded by the battery stack 14 and the case 20.

  The intake chamber 22 and the exhaust chamber 26 are arranged so that the battery stack 14 is sandwiched between them. Further, the intake chamber 22 and the exhaust chamber 26 are adjacent to a surface including the stacking direction (x axis) of the battery modules 16, so that each communicates with both ends of the cooling passage 18 formed between the battery modules 16. Yes.

  In the cooling system 10 shown in FIG. 1, the intake chamber 22 is provided adjacent to the lower surface of the battery stack 14, and the case 20 is surrounded except for the lower surface of the battery stack 14. The exhaust chamber 26 is provided adjacent to the upper surface of the battery stack 14, and a portion other than the upper surface of the battery stack 14 is surrounded by the case 20.

  The arrows in FIG. 1 indicate the flow of cooling air that flows inside the battery pack 12. The cooling air flows through a flow path from the intake chamber 22 through the cooling passage 18 to the exhaust chamber 26, and the battery module 16 is cooled while the cooling air passes through the cooling passage 18. The cooling air after passing through the cooling passage 18 is also referred to as “exhaust”.

  The arrangement of the intake chamber 22 and the exhaust chamber 26 is not limited as long as the above requirements are satisfied. As shown in FIG. 1, the intake chamber 22 is adjacent to the lower surface of the battery stack 14, and the exhaust chamber 26 is the upper surface of the battery stack 14. It is preferable that it adjoins. A liquid such as water or a foreign matter such as sand mud taken into the intake chamber 22 together with the cooling air is prevented from fouling the battery stack 14, and the interference of the rising air flow generated when the cooling air is warmed in the cooling passage 18. Is to prevent.

The intake chamber 22 is provided with an intake port 24, and the cooling air flows into the intake chamber 22 through the intake port 24. In the present embodiment, a Z-turn system is adopted, and the intake port 24 is provided on the side surface of the case 20 surrounding the intake chamber 22. In Figure 1, air inlet 24, that is formed on one (first surface 32) of the surface crossing the x-axis is a lamination direction of the battery module 16.

  The blower 50 communicates with the intake chamber 22 through the intake port 24. The blower 50 is configured by a discharge type fan or blower, takes in outside air from the outside of the battery pack 12, and supplies this to the intake chamber 22 as cooling air. An intake duct (not shown) that guides outside air to the blower 50 is connected to the blower 50. In some cases, an air intake duct connecting the air inlet 24 and the blower 50 may be provided.

  The exhaust chamber 26 is provided with an exhaust port 28, and the cooling air flows out of the exhaust chamber 26 through the exhaust port 28. The exhaust port 28 is provided on a side surface of the case 20 surrounding the exhaust chamber 26 that faces the side surface where the intake port 24 is provided. In FIG. 1, the exhaust port 28 is formed in a surface (second surface 34) that intersects the x axis that is the stacking direction of the battery modules 16 and faces the first surface 32 in the battery pack 12. ing.

  The exhaust duct 60 is connected to the exhaust port 28 and communicates with the exhaust chamber 26 via the exhaust port 28. Exhaust gas is guided from the exhaust chamber 26 to the outside of the case 20 by the exhaust duct 60.

As shown in FIG. 1, the battery pack 12, the two surfaces intersecting with the x-axis is a lamination direction of the battery module 16 that Do a first surface 32 and second surface 34. This is because the cooling system 10 including the battery pack 12, the blower 50, the exhaust duct 60, and the like can be reduced in height and compactly arranged.

  In the cooling system 10 of the present embodiment, the exhaust chamber 26 is provided with a ventilation portion 30, and a part of the exhaust gas in the exhaust chamber 26 flows out of the case 20 through the ventilation portion 30. To do. Since the cooling system 10 of the present embodiment includes the discharge type blower 50 that supplies the cooling air to the intake chamber 22, the internal pressure of the exhaust chamber 26 becomes higher than the pressure outside the case 20. As a result, the exhaust in the exhaust chamber 26 flows out of the case 20 through the ventilation portion 30.

  The ventilation portion 30 is provided in the exhaust chamber 26 on the upstream side (the negative direction of the x axis in FIG. 1) from the downstream end of the exhaust where the exhaust port 28 is provided. The number, size, and shape of the ventilation portion 30 can be appropriately changed according to the configuration of the battery stack 14, the blowing capacity of the blower 50, and the like. The ventilation portion 30 may have any shape as long as the exhaust chamber 26 and the case 20 are communicated with each other. For example, the ventilation portion 30 may be an opening formed in the case 20, and both ends of the exhaust chamber 26 and the case 20. It may be a tubular body communicating with each outside. A plurality of ventilation portions 30 may be provided in the exhaust chamber 26, the ventilation portions 30 may be long along the stacking direction of the battery modules 16, or a composite of these.

  FIG. 4 shows a conventional Z-turn cooling system 70. In FIG. 4, the flow of the cooling air is indicated by an arrow, and members that are the same as those in FIG. In the conventional cooling system 70 shown in FIG. 4, the ventilation portion 30 is not provided, and the exhaust from the exhaust chamber 26 is exhausted only through the exhaust port 28.

  In FIG. 4, in the battery pack 12, the 1st surface 32 in which the inlet port 24 is provided, and the 2nd surface 34 in which the exhaust port 28 is provided are facing. As a result, as shown in FIG. 4, the cooling air and the exhaust gas are directed from the first surface 32 side to the second surface 34 side in both the intake chamber 22 and the exhaust chamber 26 (the positive direction of the x axis). Flowing into. Thus, in the Z-turn system, the upstream side and the downstream side of the cooling air coincide with each other in the intake chamber 22 and the exhaust chamber 26.

  Here, in the intake chamber 22, since the cooling air is supplied from the blower 50 through the intake port 24, the pressure increases toward the downstream side (the positive direction of the x axis). On the other hand, in the exhaust chamber 26, the internal pressure decreases toward the exhaust port 28 near the outside of the case 20, that is, toward the downstream side (the positive direction of the x axis). In the Z-turn system, as shown in FIGS. 1 and 4, the airflow direction of the cooling air is the same in the intake chamber 22 and the exhaust chamber 26. Therefore, the pressure difference between the intake chamber 22 and the exhaust chamber 26 is the smallest at the upstream end (the intake port 24 side), and becomes larger toward the downstream side (the positive direction of the x axis), and the downstream end (the exhaust port 28). Side)).

  As shown in FIG. 4, both ends of the cooling passage 18 communicate with the intake chamber 22 and the exhaust chamber 26, respectively, and the amount of cooling air flowing through the cooling passage 18 is proportional to the pressure difference between the two chambers. Therefore, the amount of cooling air flowing through the cooling passage 18 is biased in the stacking direction of the battery modules 16 and tends to increase as it goes in the positive direction of the x axis. If the amount of cooling air flowing through the cooling passage 18 is biased depending on the position inside the battery stack 14 as described above, the temperature distribution inside the battery stack 14 may vary.

  In the cooling system 10 of the present embodiment, the exhaust gas in the exhaust chamber 26 is not only exhausted from the exhaust port 28 but also through the ventilation portion 30 provided in the exhaust chamber 26 compared to the conventional Z-turn cooling system 70. It is discharged to the outside of the case 20. Thereby, the internal pressure of the exhaust chamber 26 is lowered, and the deviation of the pressure difference between the two chambers in the x-axis direction is alleviated. As a result, the deviation in the x-axis direction of the cooling airflow flowing through the cooling passage 18 can be suppressed, and the temperature distribution in the battery stack 14 can be made more uniform.

  Further, in the cooling system 10 of the present embodiment, the pressure on the upstream side of the exhaust chamber 26 is reduced by providing the vent portion 30 in the exhaust chamber 26 as compared with the case where the vent portion 30 is not provided. Thus, the pressure loss of the exhaust gas flowing through the exhaust chamber 26 can be reduced. As a result, even with the blower 50 having the same blowing capacity, the amount of exhaust air flowing through the exhaust chamber 26 and, consequently, the total amount of cooling air passing through the inside of the battery stack 14 increases. Therefore, the cooling system 10 of this embodiment also has an advantage that the overall cooling efficiency of the battery stack 14 can be improved.

From the viewpoint of alleviating the uneven pressure difference between the two chambers and reducing the pressure loss, the ventilation portion 30 is upstream of the intermediate portion between the upstream end and the downstream end in the exhaust chamber 26, and further, the first portion. It is preferable to be provided in the vicinity of the surface 32. Further, a plurality of ventilation portions 30, along the stacking direction of the battery module 16 and form one or more columns, passing the gas portion 30 is provided between the cooling passage 18 is the battery module 16 provided Tei Ru.

  FIG. 2 shows an example of a specific configuration of the battery pack 12 according to the present embodiment. FIG. 2 is a cross-sectional view of a plane perpendicular to the stacking direction (x axis) of the battery modules 16. In FIG. 2, arrows and symbols indicate the flow of cooling air inside the battery pack 12.

  In the battery pack 12 shown in FIG. 2, a portion surrounding the exhaust chamber 26 as the case 20 has a structure in which a plate-like lower member 36 and an upper member 38 are stacked. The lower member 36 surrounds the side surface of the exhaust chamber 26 and has a structure in which a wide opening is provided in the upper portion of the exhaust chamber 26. The upper member 38 surrounds the upper surface of the exhaust chamber 26 so as to cover the entire opening of the lower member 36, and forms a space that communicates the exhaust chamber 26 and the outside of the case 20 between the lower member 36. It has such a structure. In FIG. 2, the space formed by the lower member 36 and the upper member 38 becomes the ventilation portion 30, and a part of the exhaust is discharged from the exhaust chamber 26 to the outside of the case 20.

  FIG. 3 shows an example of a more specific structure of the lower member 36 and the upper member 38 shown in FIG. The arrows in FIG. 3 indicate the flow of cooling air. 2 and FIG. 3, the exhaust chamber 26 is provided adjacent to the upper surface of the battery stack 14, so that even if the battery pack 12 is splashed with water, the exhaust chamber 26 is provided. Can prevent water inside.

  DESCRIPTION OF SYMBOLS 10 Cooling system, 12 Battery pack, 14 Battery stack, 16 Battery module, 18 Cooling passage, 20 Case, 22 Intake chamber, 24 Intake port, 26 Exhaust chamber, 28 Exhaust port, 30 Ventilation part, 32 1st surface, 34 Second side, 50 blower, 60 exhaust duct.

Claims (1)

A plurality of battery modules are stacked, a battery stack provided with a cooling passage through which cooling air passes between the battery modules, a case for housing the battery stack, an intake chamber extending in the stacking direction, and a stack An exhaust chamber extending in a direction, and the intake chamber and the exhaust chamber are disposed so as to sandwich the battery stack, and each of the intake chamber and the exhaust chamber communicates with both ends of the cooling passage. A battery pack,
A blower for supplying cooling air to the intake chamber;
A battery cooling system comprising:
An inlet port through which cooling air flows into the intake chamber is provided on the first surface of the battery pack;
An exhaust port through which cooling air flows out from the exhaust chamber is provided on a second surface facing the first surface of the battery pack,
The first surface and the second surface are surfaces that intersect with an axis that is the stacking direction of the battery modules,
The exhaust chamber is provided with a plurality of ventilation portions through which cooling air flows from the exhaust chamber to the outside of the case. The ventilation portions are disposed between the battery modules and are arranged in the stacking direction of the battery modules. In line with the
Battery cooling system.