KR20220105841A - Battery cooling apparatus - Google Patents

Abstract

The present invention relates to a battery pack cooling device including: a lower case having an accommodation space for installing a plurality of battery packs; a cooling plate attached to the lower part of the lower case; a passage formed in a U-turn shape structure including an inflow passage that starts from one end in the longitudinal direction and proceeds to an opposite end and an outflow passage that makes a U-turn and returns to one end; and a thermal balance member that is attached to the lower case and thermally connects the inflow passage and the outflow passage, thereby cooling the battery packs more efficiently and improving cooling performance.

Description

Battery cooling apparatus {Battery cooling apparatus}

The present invention relates to a battery pack cooling device, and to a battery pack cooling device for cooling a battery pack more efficiently and improving cooling performance.

In general, an eco-friendly vehicle such as a hybrid vehicle or an electric vehicle is equipped with a battery pack for applying power to a driving motor.

The battery pack includes a plurality of unit battery modules, and one battery module includes a plurality of battery cells.

Since these battery packs generate heat during operation, cooling is required to maintain the appropriate temperature of the battery pack.

A method of cooling the battery pack includes an air cooling type and a water cooling type.

However, in recent years, as the development of a hybrid vehicle into a plug-in hybrid vehicle or an electric vehicle progresses, the capacity of the battery is becoming more high-capacity.

The water cooling type may be further divided into a direct water cooling type and an indirect water cooling type. In the indirect water cooling type, the cooling water does not directly cool the battery cells, but cools the battery cells through a cooling plate.

Such water cooling also requires improvement in cooling performance as the battery increases in capacity.

Accordingly, there is a need for research and development on a method of cooling the battery having a high capacity.

Matters described in the background section are prepared to promote understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

The present invention has been devised in the background described above, and it is an object of the present invention to provide a battery pack cooling device that improves cooling efficiency by forming a coolant flow path in direct contact with a lower portion of a battery module.

In addition, a thermal balance member for thermally connecting the inflow flow path and the outflow flow path is provided to prevent the cooling performance of the outlet flow path from being deteriorated, and to provide a battery pack cooling device capable of uniformly cooling the battery pack as a whole. have.

In addition, an object of the present invention is to provide a battery pack cooling device in which the flow path is provided in a U-turn shape structure so that the inlet and the outlet can be arranged on one side, so that the overall structure can be miniaturized.

In addition, the inflow passage and the outflow passage are provided asymmetrically to cool the battery pack more effectively, and by uniformly cooling the battery pack as a whole, it is possible to reduce the deviation between the average temperature and the maximum temperature of the battery pack, and accordingly, the performance of the battery pack An object of the present invention is to provide a battery pack cooling device that improves the

The object of the present invention is not limited thereto, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

According to the present invention, a lower case in which an accommodation space is formed to install a plurality of battery packs, a cooling plate attached to the lower portion of the lower case, and a cooled fluid provided between the lower case and the cooling plate circulate, starting from one end in the longitudinal direction. A flow path formed in a U-turn shape including an inflow flow path that advances to the opposite end and an outflow flow path that returns to one end by u-turning, a thermal balance member attached to the lower case and thermally connecting the inflow flow path and the outflow flow path. A battery pack cooling device comprising a may be provided.

Here, the lower case may be provided with a space separation unit which is formed to be long in the width direction and is installed to divide the accommodation space.

In addition, the plurality of battery modules may be disposed to be spaced apart in the longitudinal direction, and the thermal balance member may be disposed long in the width direction between the battery modules.

In addition, the lower case may have a seating groove formed by being depressed so that the thermal balance member is inserted from the upper surface.

The thermal balance member may be a heat pipe.

In addition, the flow passages are provided asymmetrically with respect to the longitudinal axis between the inflow passage and the outlet passage, and the area of the lower case cooled by the inflow passage may be formed to be wider than the area of the lower case cooled by the outflow passage. have.

According to the present invention as described above, there is an effect that the cooling efficiency is improved by forming a flow path through which the fluid cooled by being in direct contact with the lower part of the battery pack circulates.

In addition, a thermal balance member for thermally connecting the inflow passage and the outflow passage is provided to prevent the cooling performance of the outflow passage from being deteriorated, and to evenly cool the battery pack as a whole.

In addition, as the flow path provided between the lower case and the cooling plate is provided in a U-turn structure, the inlet and the outlet can be arranged on one side, and the overall structure can be miniaturized.

In addition, the inflow and outflow channels are provided asymmetrically, so that the battery pack is cooled more effectively, and as the battery pack is cooled uniformly as a whole, the deviation between the average temperature and the maximum temperature of the battery pack can be reduced. It has the effect of improving performance.

1 is a perspective view of a lower case to which a battery pack cooling device according to an embodiment of the present invention is attached.
2 is an exploded perspective view of a lower case to which a battery pack cooling device according to an embodiment of the present invention is attached.
FIG. 3 is an enlarged view of part A of FIG. 2 .
4 is a front view of a cooling plate of a battery pack cooling device according to an embodiment of the present invention.
5 is a view showing the internal structure of the thermal balance member of the battery pack cooling device according to the embodiment of the present invention.
6 is a front view of a cooling plate of a battery pack cooling device according to another embodiment of the present invention.
7 is a diagram schematically illustrating a battery pack cooling apparatus according to the present invention and a comparative example in the same battery pack arrangement structure by comparison.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a perspective view of a lower case to which a battery pack cooling device according to an embodiment of the present invention is attached, FIG. 2 is an exploded perspective view of a lower case to which a battery pack cooling device according to an embodiment of the present invention is attached, and FIG. 3 is 2 is an enlarged view of part A, FIG. 4 is a front view of a cooling plate of a battery pack cooling device according to an embodiment of the present invention, and FIG. 5 is a thermal balance member of a battery pack cooling device according to an embodiment of the present invention 6 is a front view of a cooling plate of a battery pack cooling device according to another embodiment of the present invention, and FIG. 7 is a battery pack cooling device according to the present invention and a comparative example in the same battery pack arrangement structure It is a diagram briefly showing a comparison.

As shown in these drawings, the battery pack cooling device according to an embodiment of the present invention includes a lower case having an accommodation space for installing a plurality of battery packs, a cooling plate attached to the lower part of the lower case, and a space between the lower case and the cooling plate. The provided cooled fluid circulates, and the flow path formed in a U-turn shape including an inflow flow path starting from one end in the longitudinal direction and proceeding to the opposite end and an outlet flow path returning to one end by making a U-turn again, attached to the lower case and a thermal balance member for thermally connecting the inflow passage and the outflow passage.

However, for convenience of explanation, the direction in which the cooling plate 200 of the lower case 100 is attached is described as the lower side, and the direction opposite to the direction in which the cooling plate 200 of the lower case 100 is attached is described as the upper side. And, the vertical direction is described as the longitudinal direction with reference to FIG. 4, and the left and right directions are described as the width direction, but the present invention is not limited thereto.

The battery pack cooling device of the present invention may be applied to a battery pack of an eco-friendly vehicle.

In this case, the eco-friendly vehicle may include a hybrid vehicle as well as an electric vehicle.

Such a battery pack consists of a plurality of unit battery modules 10, and one battery module 10 consists of a plurality of battery cells.

Battery cells may be used interchangeably to refer to each battery element of any type used in a battery pack.

The battery cell according to an embodiment of the present invention includes general lithium-based batteries that can be used in electric vehicles, but includes iron phosphate, metal oxide, lithium-ion polymer, and nickel metal. Various chemical compositions including nickel metal hydride, nickel cadmium, nickel batteries (hydrogen, zinc, cadmium, etc.) and other battery types compatible with electric vehicles.

In addition, the battery cell according to the embodiment of the present invention can be applied to both cylindrical or prismatic batteries.

Since the battery pack as described above generates heat according to operation, cooling is required to maintain the battery pack at an appropriate temperature.

In particular, a desired battery performance can be provided only when the temperature of each battery cell of the battery pack is within a temperature range of a certain section, and the smaller the temperature deviation, the better the battery performance.

Accordingly, the present invention attaches the cooling plate 200 forming the flow path 300 to the lower part of the lower case 100 in which the plurality of battery modules 10 are installed, and the cooled fluid circulates in the flow path 300 . A structure for cooling the battery pack is provided.

In the lower case 100 , the receiving space 110 is formed so that a plurality of battery modules 10 are installed, and the receiving space 110 is partitioned by the space separating unit 120 , respectively.

The space separation unit 120 is installed in the lower case 100 to divide the receiving space 110 horizontally or vertically so that a plurality of battery modules 10 are spaced apart from each other and arranged side by side to prevent heat from being concentrated.

At this time, the plurality of battery modules 10 are arranged to be spaced apart from each other in the longitudinal direction or the width direction in the receiving space 110 partitioned by the space separation unit 120 of the lower case 100 in which a plurality of battery cells are formed as a unit. .

The cooling plate 200 is attached to the lower portion of the lower case 100 and forms a flow path 300 between the cooling plate 200 and the lower case 100 so that the cooled fluid circulates.

The cooling plate 200 is preferably coupled to the lower portion of the lower case 100 via a separate fastening member or integrally coupled by a bonding method such as welding so that the flow path 300 is provided as a closed space. It is not limiting.

In addition, the cooling plate 200 may be provided in a plate shape having a size corresponding to the lower surface of the lower case 100 to cover the lower portion of the lower case 100 , and is recessed from the surface facing the lower case 100 . and a flow path forming part 210 formed by being.

The flow path forming part 210 may be formed, for example, by press molding on a single cooling plate 200 in the shape of the flow path 300 , and is formed to open only toward the lower case 100 .

In this way, the flow path 300 formed between the lower case 100 and the cooling plate 200 starts at the inlet 301 and makes a U-turn so that the inlet 301 and the outlet 302 are positioned on one side of the lower case 100 . It is provided in a U-turn shape structure to come.

That is, the flow path 300 includes an inflow flow path 310 that starts at one end in the longitudinal direction and progresses to the opposite end, and an outlet flow path 320 that returns to one end by making a U-turn again. Provided in a U-turn shape structure do.

The flow path 300 is connected to a cooling system including a tank for storing the cooled fluid or a pump for circulating the fluid. As the inlet 301 and the outlet 302 are located on one side, the connection with the cooling system is It is easy, and the overall cooling system can be downsized.

In addition, in the lower case 100 , two communication holes 130 are formed through which the inlet 301 and the outlet 302 of the flow path 300 formed between the cooling plate 200 are connected.

In addition, a block-shaped connecting block 500 having two connecting holes 510 formed therein is coupled to the upper surface of the lower case 100 .

One of the two connection holes 510 has one end connected to the inlet 301 of the flow path 300 by communicating with the communication hole 130, and the other end is open to the outside, so that a pipe for supplying a cooled fluid can be connected, The other end communicates with the communication hole 130 and is connected to the outlet 302 of the flow path 300 , and the other end is opened to the outside, and a pipe for discharging the fluid circulated through the flow path 300 may be connected.

As such, the inlet 301 and the outlet 302 of the flow path 300 receive or discharge fluid through the communication hole 130 of the lower case 100 and the connection hole 510 of the connecting block 500 .

In this case, the lower case 100 may be coupled to a thermal balance member 400 that thermally connects one side and the other side in the width direction.

The flow path 300 has a structurally cooled fluid that absorbs heat from the battery pack while flowing through the inflow flow path 310, so that when it flows through the outlet flow path 320, the temperature rises somewhat. 310) and the temperature deviation of the outflow passage 320 is reduced.

The heat balancing member 400 is made of a material having a high heat transfer rate, is formed in a long bar shape in the longitudinal direction, and is long in the width direction to thermally connect the inflow passage 310 and the outflow passage 320 .

Accordingly, the thermal balance member 400 moves the heat from the other side in the width direction to one side in the width direction when the temperature of the other side in the width direction where the outlet flow path 320 is located is higher than the temperature at the one side in the width direction where the inflow flow path 310 is located. make it

The thermal balance member 400 may be provided as, for example, a heat pipe.

The thermal balancing member 400 will be described in detail with reference to FIG. 5 , the thermal balancing member 400 has an empty space in a vacuum state in which a working fluid is accommodated therein, and a gas that evaporates from the working fluid can move in the center. this is provided

And, when the heat of the battery module 10 is applied to the other side of the thermal balance member 400 in the width direction located on the outlet flow path 320, the working fluid contained therein evaporates and evaporates into an empty space. The gas moves to one side in the width direction due to the pressure difference.

The gas moving to one side in the width direction has a relatively low temperature and is changed into a working fluid while dissipating the heat it has to the outside, and the working fluid is again moved to the other side in the width direction.

As such, the thermal balance member 400 transfers heat to the opposite side when relatively heat is applied to either side of the one side and the other side, and transfers the heat from the side where the outlet flow path 320 of the lower case 100 is provided to the inflow flow path 310 . ) is rapidly moved to the side where the inlet flow path 310 and the outlet flow path 320 are thermally connected, and acts to achieve equilibrium.

As described above, as the thermal balance member 400, which is a heat pipe, is separately attached to the lower case 100, the flow direction of the fluid flowing through the flow path 300 can be simplified and the inflow path 310 and the outlet flow path 320 are separated. The temperature difference will be reduced.

The thermal balance member 400 is disposed between the plurality of battery modules 10 spaced apart from the upper surface of the lower case 100 . In particular, the thermal balance member 400 is preferably coupled to the other side opposite to the one side provided with the inlet 301 and the outlet 302 of the flow path 300 of the lower case 100 , and to the lower case 100 . It is provided in plurality and may be respectively disposed between the battery modules 10 .

The lower case 100 is provided with a seating groove 140 formed by being depressed so that the thermal balance member 400 is inserted from the upper surface on which the space separation unit 120 is installed, so that the thermal balance member 400 is connected to the flow path 300 and to be placed close together.

The seating groove 140 is formed in a rectangular groove shape corresponding to the thermal balance member 400 , and round groove-shaped machining allowances may be formed at each corner so that the thermal balance member 400 is easily assembled.

In addition, in the space separation unit 120 , a through hole 121 having a shape corresponding to that of the thermal balance member 400 is formed in order to facilitate the installation of the thermal balance member 400 .

Accordingly, even when the space separation unit 120 is installed in the lower case 100 , the operator can install or easily replace the thermal balance member 400 through the through hole 121 .

These flow paths 300 are provided asymmetrically with each other based on the longitudinal axis between the inflow flow path 310 and the outflow flow path 320 in order to evenly cool the battery pack as a whole, and the area where the inflow flow path 310 cools is The outlet flow path 320 is provided to be wider than the cooling area.

Accordingly, the inflow passage 310 cools a portion of the battery module 10 disposed on the other side in the width direction together with the entire battery module 10 disposed on one side in the width direction, so that the battery pack is uniformly cooled.

Therefore, since the temperature of the outlet channel 320 is lower than the temperature of the inlet channel 310, the channel 300 is provided with an asymmetric structure in which the inlet channel 310 is expanded and the outlet channel 320 is reduced, so that the battery pack can be stored. cooling more efficiently.

That is, the flow path 300 is asymmetrically formed so that the area of the lower case 100 cooled by the inflow flow path 310 is larger than the area of the lower case 100 cooled by the outlet flow path 320 .

In addition, the inflow flow path 310 and the outflow flow path 320 are formed to have a repeatedly curved shape in a meandering shape so that the fluid sufficiently cools the battery pack.

In addition, the inflow passage 310 and the outflow passage 320 are provided with a plurality of retention spaces 311 and 321 formed to have a larger cross-sectional area at positions corresponding to the plurality of battery modules 10 to communicate with the battery module 10 . Heat exchange proceeds.

The staying spaces 311 and 321 may be formed such that a length in the longitudinal direction approximately corresponds to the length in the longitudinal direction of the battery module 10 , and the fluid is provided to heat exchange with the battery module 10 .

In addition, the inflow-side retention space 311 formed in the inflow passage 310 is formed to have a wider width than the width of the outflow-side retention space 321 formed in the outflow passage 320, and is disposed on one side and the other side in the width direction. (10) is provided to cool.

At this time, the cooling plate 200 is formed to protrude from the flow path forming part 210 and is in close contact with the lower part of the lower case 100 to guide the flow of the fluid while spreading the fluid as a whole in the retention spaces 311 and 321 . It has a flow path separation unit 220 that forms the multi-channel (300).

In particular, a plurality of flow path separators 220 are formed in the retention spaces 311 and 321 , and the fluid flowing from one side to the other in the width direction flows between the plurality of flow path separators 220 , thereby simplifying the flow direction of the fluid.

The plurality of flow path separators 220 have a space therebetween to be narrower than the cross-sectional area of the inflow flow path 310 to slow the speed of the fluid and to sufficiently cool the battery module 10 .

In addition, FIG. 6 shows a cooling plate 200 according to another embodiment of the present invention, and the residence space 322 of the outlet flow path 320 is meandering in order to increase the speed of the fluid flowing through the outlet flow path 320 . It is formed into an 'S' shape that is repeatedly bent into one shape.

At this time, the cross-sectional area of the outlet-side retention space 322 is formed to be wider than the cross-sectional area of the portion divided by the plurality of flow path separation units 220 of the inlet-side retention space 311 , so that the outflow velocity of the fluid becomes faster than the inflow velocity.

Also, the inflow passage 310 may have a cross-sectional area equal to or smaller than the cross-sectional area of the outlet passage 320 so that the velocity of the fluid is slowed.

7 shows a comparative example in which a cooling plate 200 ′ forming a flow path 300 ′ having a symmetric structure is attached to the lower case 100 , and a flow path 300 having an asymmetric structure is formed in the lower case 100 . The present invention is shown in a state in which the cooling plate 200 is attached.

Here, in the battery module 10, for example, two battery cells are arranged individually on the inlet 301 side and the outlet 302 side of the flow path 300 to save space, and the length is on one side and the other side in the width direction. It may be spaced apart in the direction and arranged three by one as a unit.

And the flow path 300' shown in FIG. 7 (a) directly cools only the battery module 10 having the inflow flow path disposed on one side in the width direction, and the battery module 10 having the outlet flow path disposed on the other side in the width direction. ) is directly cooled, a temperature difference is generated between the one side and the other side of the battery module 10 in the width direction spaced apart from each other.

That is, since the temperature of the fluid flowing through the inlet flow path is lower than the temperature of the fluid flowing through the outlet flow path, the battery module 10 disposed on one side in the width direction is cooled more than the battery module 10 disposed on the other side in the width direction, so that the battery module ( 10) The temperature difference between the two becomes large and the performance of the battery deteriorates.

In addition, the battery module 10 disposed on the outlet flow path is not sufficiently cooled and thus has heat, and thus heat is also transferred to the battery module 10 disposed on the inflow channel, thereby increasing the overall battery pack temperature. will be.

In particular, since the battery module 10 disposed on one side of the width direction and the battery module 10 disposed on the other side of the width direction are spaced apart by a predetermined interval, heat exchange between the battery modules 10 is better than between the battery cells. Therefore, when the inflow passage cools only the battery module 10 disposed on one side in the width direction, the temperature difference with the battery module 10 disposed on the other side in the width direction increases.

On the other hand, in the flow path 300 shown in (b) of FIG. 7 , the width direction of the inflow flow path 310 is longer than the width direction of the outlet flow path 320 , so that the inflow flow path 310 is formed in the width direction. Some battery cells of the battery module 10 disposed on one side and the battery module 10 disposed on the other side in the width direction are cooled together.

Accordingly, the battery module 10 disposed on the other side of the width direction can also be cooled by the inflow flow path 310, and as it is cooled once more by the outflow flow path 320, the conventionally reduced local cooling performance. can be prevented.

In addition, a thermal balance member 400 for thermally connecting one side and the other side in the width direction is provided so that the heat of the battery module 10 disposed on the outlet flow passage 320 is partially disposed on the inflow passage 310 . It is moved to the battery module 10 side, and the battery pack is evenly cooled as a whole.

In fact, comparing the cooling performance with the structures of (a) and (b) of Figure 7, in the case of (a) of Figure 7, the lowest temperature is 26.13 ℃, the highest temperature is 31.38 ℃, the average temperature is 28.19 ℃, the highest temperature and The average temperature deviation is 3.19℃, so the overall temperature is high and the temperature is not uniformly cooled, so the temperature of the battery cell arranged at the other end of the width direction is slightly higher and the operating performance is deteriorated.

On the other hand, in the case of (b) of FIG. 7, the lowest temperature is 25.95°C, the highest temperature is 29.97°C, and the average temperature is 28.09°C, and the difference between the highest temperature and the average temperature is 1.88°C. The overall operating performance is improved, and the operating performance of the battery cell disposed at the other end in the width direction is also improved compared to the prior art.

At this time, the battery cell disposed on the portion connected to the inlet 301 of the inlet flow path 310 of the battery pack has the highest temperature, and the battery cell disposed at the other end of the width direction of the outlet flow path 320 has the lowest temperature. .

According to the embodiments of the present invention having such a shape and structure, the cooling efficiency is improved by forming a flow path through which the cooled fluid circulates in direct contact with the lower part of the battery pack.

In addition, a thermal balance member for thermally connecting the inflow passage and the outflow passage is provided to prevent the cooling performance of the outflow passage from being deteriorated, and to evenly cool the battery pack as a whole.

In addition, as the flow path provided between the lower case and the cooling plate is provided in a U-turn structure, the inlet and the outlet can be arranged on one side, and the overall structure can be miniaturized.

In addition, the inflow and outflow channels are provided asymmetrically, so that the battery pack is cooled more effectively, and as the battery pack is cooled uniformly as a whole, the deviation between the average temperature and the maximum temperature of the battery pack can be reduced. It has the effect of improving performance.

In the above, even though all the components constituting the embodiment of the present invention are described as being combined or operating in combination, the present invention is not necessarily limited to this embodiment. That is, within the scope of the object of the present invention, all the components may operate by selectively combining one or more.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

10: battery pack 100: lower case
110: accommodation space 120: space separation unit
121: through hole 130: through hole
140: seating groove 200: cooling plate
210: flow path forming unit 220: flow path separation unit
300: Euro 301: Entrance
302: exit 310: inflow path
320: outflow passage 400: thermal balance member

Claims (6)

a lower case having an accommodating space in which a plurality of battery packs are installed; and
a cooling plate attached to a lower portion of the lower case;
A U-turn-shaped structure comprising an inflow passage that is provided between the lower case and the cooling plate and circulates a cooled fluid, and proceeds from one end of the longitudinal direction to the opposite end, and an outlet passage that returns to one end by making a U-turn again. a flow path formed by; and
and a thermal balance member attached to the lower case and thermally connecting the inflow passage and the outflow passage.
The method of claim 1,
The battery pack cooling device, characterized in that the plurality of battery modules are arranged to be spaced apart in the longitudinal direction, and the thermal balance member is arranged long in the width direction between the battery modules.
The method of claim 1,
The battery pack cooling device, characterized in that the lower case is provided with a seating groove formed by being depressed so that the thermal balance member is inserted from the upper surface.
The method of claim 1,
The heat balancing member is a battery pack cooling device, characterized in that the heat pipe.
The method of claim 1,
The lower case is formed to be long in the width direction, and the battery pack cooling device, characterized in that it has a space separation unit installed to divide the receiving space.
The method of claim 1,
The flow passages are provided asymmetrically with respect to a longitudinal axis between the inflow passage and the outlet passage, and the area of the lower case cooled by the inflow passage is greater than the area of the lower case cooled by the outflow passage. A battery pack cooling device, characterized in that it is formed widely.

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