JP2016100193A - Cooling device for battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress rise in pipe internal pressure in a cooling passage of a cooling device.SOLUTION: A cooling device for a battery pack comprises: a cooling passage 12 in which cooling water 11 flows; a pump 13 for making the cooling water 11 circulate in the cooling passage 12; an inclined passage 121 that communicates with the cooling passage 12, is in contact with respective surfaces 20a and 20b, which are positioned opposite each other, of neighboring cells between the cells in a battery pack 2 in which a plurality of cells 20 are aligned, and that is inclined upward from a lower part of the cell toward an upper part; and a valve 14 arranged at the cooling passage side communicating with the inclination upper side of the inclination passage 121, and that discharges a pressure in the cooling passage to outside the cooling passage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery pack cooling apparatus.

  A vehicle having an electric motor as an electric drive source or a vehicle having both an electric motor and an internal combustion engine is equipped with a high-voltage and large-capacity battery pack serving as a power source for the electric motor. In the battery pack, a plurality of cells are arranged adjacent to each other, and each cell generates heat due to charging and discharging. The vehicle is equipped with a cooling device that suppresses the temperature rise of the battery pack by cooling each cell. As the cooling device, there are an air cooling type and a water cooling type. As a water-cooling type cooling device, a cooling path through which a cooling liquid flows is arranged between cells, and a cooling liquid in the cooling path is circulated by operating a pump as a driving source (for example, Patent Document 1). ).

JP 2013-62207 A

In the case of a water-cooled cooling device, the heat of the battery pack (cell) is transferred to the cooling water through the cooling path, but when the cooling water becomes a temperature higher than the boiling point and vaporizes, bubbles are generated and the heat in the cooling path is increased. The pressure inside the pipe increases, and excessive pressure resistance is required for the cooling path. Even when the pump becomes unusable, it is desirable to suppress the rise in the pipe pressure in the cooling path for safety.
An object of the present invention is to suppress an increase in the pressure in the pipe in the cooling path of the cooling device.

  In order to achieve the above object, a battery pack cooling apparatus according to the present invention includes a cooling path through which cooling water flows, a pump for circulating cooling water in the cooling path, a cooling path, and a plurality of cells. In the battery packs arranged side by side, the adjacent surfaces of the cells in contact with each other between the adjacent cells, and the slope inclined upward from the lower part of the cell toward the upper part, and the slope upper side of the slope It has the valve | bulb arrange | positioned at the side of the cooling path which connects, and discharges | emits the pressure in a cooling path out of a cooling path.

  According to the present invention, the battery pack in which a plurality of cells are arranged side by side is in contact with the surfaces facing each other between adjacent cells in the battery pack in which the cooling water flows through the inside, and The pump stops because it has a valve that slopes upward from the lower part of the cell to the upper part, and a valve that discharges the pressure in the cooling path to the outside of the cooling path. Even in this case, since the bubbles generated in the cooling path rise by natural convection of the cooling water generated along the inclined path and are discharged from the valve, an increase in the pressure in the pipe in the cooling path can be suppressed.

The schematic block diagram of the vehicle provided with the cooling device of the battery pack which concerns on this invention. The top view explaining schematic structure of the cooling device of the battery pack which concerns on this invention. The side view explaining the principal part structure of the 1st Embodiment of this invention. The enlarged view explaining the structure and arrangement | positioning of a ramp. The enlarged view which planarly viewed the composition and arrangement of the ramp. The enlarged view which looked at the structure and arrangement | positioning of the ramp as seen from the side. The enlarged view explaining the structure and arrangement | positioning of the ramp provided with the fin used as the principal part of the 2nd Embodiment of this invention. The enlarged view which looked at the structure and arrangement | positioning of the ramp provided with the fin used as the principal part of the 2nd Embodiment of this invention by the side view. The schematic block diagram which shows the modification of the cooling device of the battery pack which changed arrangement | positioning of a valve. The schematic block diagram which shows the modification of the cooling device of the battery pack connected with another cooling device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment and modification, etc., the same member and the member having the same function are denoted by the same reference numerals, and redundant description is omitted.
In FIG. 1, the vehicle denoted by reference numeral 1 supplies electric power from a battery pack 2 serving as a power supply unit to an electric motor 4 serving as a driving unit via an inverter 3, and rotates the electric motor 4 to rotate and drive the wheels 5. And run. The vehicle 1 may be either an electric vehicle provided with the electric motor 4 or a hybrid type vehicle provided with both the electric motor 4 and the internal combustion engine. In the present embodiment, the vehicle 1 rotationally drives the rear wheels 5B (wheels 5) that serve as driving wheels by the electric motor 4, but may be a vehicle that rotationally drives the front wheels 5A (wheels 5).

  The battery pack 2 is disposed on a shielding plate 8 disposed below a floor 7 provided in the vehicle interior 6 of the vehicle 1. As shown in FIG. 2, the battery pack 2 includes a plurality of cells 20 arranged in the casing 2A side by side in the vehicle width direction indicated by the arrow Y as one module, and the vehicle width direction Y and the arrow A power supply unit including a plurality of modules arranged in the vehicle longitudinal direction indicated by X is configured. The battery pack 2 can output a high voltage by connecting the + terminal and the − terminal of each module with the same polarity in series. Each cell is a secondary battery such as a lithium ion battery, and generates heat during charging and discharging. When this heat generation reaches the allowable limit of the cell 20, it may generate heat at a high temperature, for example, 300 degrees or more.

(First embodiment)
The vehicle 1 includes a cooling device 10 in order to maintain the temperature of the battery pack 2 (cell 20) in an appropriate range. 2 and 3, the cooling device 10 is provided in the cooling path 12 through which the cooling water 11 flows, the pump 13 that circulates the cooling water 11 in the cooling path 12, and the cooling path 12. A valve 14 that discharges the pressure in the passage 13 to the outside of the cooling passage and a cooling water reservoir 15 that communicates with the cooling passage 12 are provided. The cooling path 12 has an inclined path 121 disposed between adjacent cells in the battery pack 2 in which the plurality of cells 20. Since the configuration of the ramp 121 arranged between the cells is the same, the configuration of the ramp 121 and the cooling channel 12 corresponding to one module will be described below.

  The cooling path 12 is made of a metal and a rectangular hollow tube member. For this reason, the surface of the pipe member is subjected to insulation treatment. The cooling path 12 may be a resin pipe member instead of a metal pipe member. The cooling path 12 includes a supply path 122 serving as a first path for supplying the cooling water 11 to the ramp 121 and a recovery path 123 serving as a second path for collecting the cooling water that has passed through the ramp 121. ing. The supply path 122 is arranged below the lower part 20c of the cell 20 as shown in FIGS. 3, 4 and 6, and the recovery path 123 is below the upper part 20d of the cell 20 and is in the central part 20e of the cell 20. It is arranged above. The supply path 122 is connected to the lower end 121 c that is one end of the ramp 121, and the recovery path 123 is connected to the upper end 121 d that is the other end of the ramp 121. That is, the cooling device 10 includes a supply path 122 serving as a first path communicating with the lower end 121c of the ramp 121 and a recovery path 123 serving as a second path communicating with the upper end 121d of the ramp 121. .

  As shown in FIGS. 2 and 3, the pump 13 is a fluid pump and is disposed in the supply path 122 outside the casing 2 </ b> A (battery pack 2). The cooling device 10 includes a temperature sensor 17 as temperature detection means for detecting the temperature of the cooling water 11 in the cooling path 12. The temperature sensor 17 is connected to the control unit 60 via a signal line. The control unit 60 is a computer and receives temperature information detected by the temperature sensor 17. The controller 60 controls the driving of the pump 17 based on the temperature information from the temperature sensor 17. When the temperature of the cooling water 11 in the cooling path 12 becomes equal to or higher than the predetermined temperature, the control unit 60 drives the pump 13 so that the cooling water 11 circulates in the cooling path 12, and when the temperature is lower than the predetermined temperature, The drive of the pump 13 is stopped.

As shown in FIGS. 4 and 5, the ramp 121 penetrates the case 70 of the module having a plurality of cells 20 inside from the lower side to the upper side, and passes through both ends of the case 70. The lower end 121c and the upper end 121d are projected. As shown in FIG. 5, the facing surfaces 121 a and 121 b of the ramp 121 facing the cells 20 are bonded to the surfaces 20 a and 20 b of the cells 20 facing each other with an adhesive having high thermal conductivity. In contact. As shown in FIG. 4, the ramp 121 is inclined upward from the lower part 20 c of each cell 20 toward the upper part 20 d and passes through a central part 20 e located between the lower part 20 c and the upper part 20 d of the cell 20. Arranged between the cells 20.
The cooling water reservoir 15 is composed of a tank having a capacity larger than at least the total capacity of the cooling water 11 flowing in the cooling path 12, and stores the cooling water 11. The cooling water reservoir 15 is disposed between the supply path 122 and the recovery path 123 upstream of the pump 13 and connected to the supply path 122 and the recovery path 123.

In the cooling device 10 having such a configuration, as shown in FIG. 3, the pump 13 is driven when the temperature of the cooling water 11 becomes equal to or higher than a predetermined temperature, and the cooling water 11 is connected to the discharge port side of the pump 13. From 122, it passes through the inclined path 121, flows to the recovery path 123 connected to the suction port of the pump 13 via the cooling water reservoir 15, and circulates in the cooling path 12.
As shown in FIGS. 4 to 6, the heat generated in the cell 20 is transmitted from the surfaces 20 a and 20 b of each cell 20 to the cooling water 11 through the facing surfaces 121 a and 121 b of the ramp 121. Thereby, the cell 20 is cooled, and as a result, the battery pack 2 is cooled, and the temperature rise is suppressed. For this reason, the temperature of the cooling water 11 in the recovery path 123 is higher than the temperature of the cooling water 11 in the supply path 122, and natural convection occurs in the cooling path 12 due to the temperature difference between the two. The cooling water 11 is heated by the heat from the cell 20 and may exceed the boiling point depending on the calorific value. When the cooling water 11 exceeds the boiling point, it is vaporized to become steam, and bubbles 16 are generated in the cooling water 11.
The valve 14 is a relief valve (pressure adjusting valve) that opens when a predetermined pressure is reached, and a recovery path 123 (cooling path 12) that communicates with the upper side of the inclined path 121 outside the casing 2 </ b> A (battery pack 2). ). The valve 14 is set to open when the pressure in the pipe in the cooling passage 12 reaches a predetermined pressure of atmospheric pressure + α. The valve 14 is provided on the upper surface 123 a of the recovery path 123 that is the highest position of the cooling path 12.

  The bubbles 16 generated in the cooling path 12 accumulate on the upper surface 123a side of the recovery path 123 through the inclined path 121 due to the difference in height between the supply path 122 and the recovery path 123 and the temperature difference of the cooling water 11, and thus the cooling path 12 When the pipe internal pressure reaches a predetermined pressure, the valve 14 discharges the cooling path 12 (recovery path 123). At this time, since the valve 14 is disposed outside the casing 2A of the battery pack 2, the bubbles 16 (steam) discharged from the valve 14 do not accumulate in the casing 2A. For this reason, it is possible to prevent the inside of the battery pack 2 from being heated by the bubbles 16 (steam) discharged from the valve 14.

According to such a configuration of the cooling device 10 according to the present embodiment, an increase in the pipe pressure in the cooling passage 12 of the cooling device 10 can be suppressed, and an excessive pressure resistance performance is exerted on the cooling passage 12 and the pump 13. No need to set. The supply path 122 of the cooling water 11 and the recovery path 123 of the cooling water 11 are in a positional relationship such that the recovery path 123 is located above the vehicle with respect to the supply path 122. The inclined path 121 has a lower end 121 a connected to the supply path 122 and an upper end 121 b connected to the recovery path 123. For this reason, even when the pump 13 is not driven due to a failure or the like, excessive pressure is discharged from the recovery passage 123 via the valve 14 when the pipe pressure in the cooling passage 12 reaches a predetermined pressure. When excessive pressure is discharged from the valve 14, a pressure difference further occurs between the supply path 122 and the recovery path 123 in the cooling path 12, and natural convection is more strongly generated in the cooling path 12. For this reason, the bubbles 16 generated in the supply path 12 are conveyed to the recovery path 123 by natural convection of the cooling water 11 and discharged from the valve 14. Therefore, even when the pump 13 does not operate, an increase in the pipe pressure in the cooling path 12 can be suppressed more stably.
Since the ramp 121 is disposed between the cells 20 and 20 facing each other, it also functions as an inter-cell spacer. Therefore, even when one cell 20 generates excessive heat, it is possible to suppress an increase in the temperature of another cell 20 adjacent thereto. Since the ramp 121 is installed so as to pass through the central portion 20e of each adjacent cell 20, the cooling water 11 is guided to the portion where the heat generation temperature of the cell 20 is high, and the amount of heat transmitted to the cooling water 11 is large. Cooling efficiency can be increased.

  In the present embodiment, the cooling water reservoir 15 is disposed on the vehicle upper side of the substantially central portion 20e located between the lower portion 20c and the upper portion 20d of the cell 20. For this reason, when the pressure in the pipe reaches a predetermined pressure while the pump 13 is stopped, the bubbles 16 and the steam are discharged from the valve 14 to the outside of the cooling path 12, and the cooling water 11 in the cooling path 12 decreases in amount. The cooling water 11 in the water reservoir 15 falls into the supply path 122 by its own weight. Therefore, even when the pump 13 is stopped, the cooling water 11 can be supplied to the supply path 122 side, so that it is possible to suppress the cooling failure of each cell 20 due to the lack of cooling water, and as a result, the increase in pipe pressure It leads to suppression.

(Second Embodiment)
As shown in FIG. 7, the cooling device 10A according to the present embodiment is connected to the ramp 121 and the surfaces 20a and 20b of each cell 20, and is opposed to the opposing surfaces 121a and 121b of the ramp 121 indicated by a broken line and the cell. It has the fin 127 arrange | positioned in the site | part different from the contact area Z with each surface 20a, 20b. As shown in FIG. 8, the fin 127 is made of a metal member having a U-shaped cross section. As shown in FIG. 7, the fins 127 are bonded and bonded to the upper surface 121 e and the surfaces 20 a and 20 b of the ramp 121 and the lower surface 121 f of the ramp 121 and the surfaces 20 a and 20 b, respectively. Has been.
When the fins 127 are provided as described above, the heat receiving area from each cell 20 to the ramp 121 is larger than that in the configuration without the fins 127. For this reason, heat can be efficiently transmitted to the cooling water 11 in the ramp 121, and the temperature increase of the cell 20 can be more stably suppressed.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.
For example, in the first and second embodiments, the valve 14 is provided on the upper surface 123a of the recovery path 123 arranged at the top of the cooling path 12, but as shown in FIG. Alternatively, the space portion 28 that protrudes upward from the upper surface 123 a may be formed, and the valve 14 may be provided on the upper portion 28 a of the space portion 28. In this case, the bubbles 16 in the cooling path 12 are carried into the cooling water reservoir 15 by the flow of the cooling water 11 and accumulated in the space 28, and by discharging the accumulated bubbles 16 from the valve 14, An increase in the pipe pressure can be suppressed.

As shown in FIG. 10, the vehicle 1 includes a water-cooled drive cooling device 100 that cools the drive system 104 such as the inverter 3 and the electric motor 4 separately from the cooling device 10 of the battery pack 2. is there. The drive cooling device 100 includes a supply path 101 that supplies cooling water to the drive system 104, a recovery path 102 that recovers cooling water heat-exchanged by the drive system 104, a supply path 101, a drive system 104, and a recovery path for cooling water. A cooling pump 103 for driving that circulates in the passage 102 is provided. In the case where such a drive cooling device 100 is provided, by connecting the supply passage 101 and the recovery passage 102 to the cooling water reservoir 15, the cooling water on the drive cooling device 100 side is cooled by the cooling device 10 of the battery pack 2. This is preferable because it can be used as water and the shortage of cooling water on the cooling device 10 side can be compensated.
The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. It is not a thing.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Battery pack, 4 ... Drive part 10, 10A ... Cooling device, 11 ... Cooling water, 12 ... Cooling path, 13 ... Pump, 14 ... Valve, 15 ... Cooling water reservoir, 20 ... Multiple cells, 20a, 20b ... Cell surface, 20c ... Lower cell, 20d ... Upper cell, 20e ... The approximate center of the cell, 121... Ramp, 121a... Lower end of the ramp, 121b... The upper slope side (upper end of the ramp), 122. ... Second path, Z ... Contact area

Claims (4)

A cooling path through which cooling water flows,
A pump for circulating cooling water in the cooling path;
In the battery pack that is in communication with the cooling path and in which a plurality of cells are arranged side by side, the adjacent cells are in contact with each other facing each other and are inclined upward from the bottom to the top of the cells. The ramp and
A cooling device for a battery pack, comprising: a valve disposed on the cooling path side that communicates with an upper slope side of the ramp path and that discharges the pressure in the cooling path to the outside of the cooling path. The battery pack cooling device according to claim 1, wherein
A cooling water reservoir that communicates with the cooling path;
The cooling water reservoir is a cooling device for a battery pack, which is disposed on the vehicle upper side with respect to a substantially central portion located between a lower portion and an upper portion of the cell. The battery pack cooling device according to claim 1 or 2,
The cooling path has a first path communicating with the lower end of the ramp and a second path communicating with the upper end of the ramp;
The said valve is a cooling device of the battery pack provided in the said 2nd path | route, and is arrange | positioned on the outer side of the said battery pack. The battery pack cooling device according to claim 1, 2, or 3,
A battery pack cooling device having fins connected to the ramps and the surfaces of the cells, and having fins disposed at different locations from the contact area between the ramps and the surfaces of the cells.

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