DE102011016738A1 - Cooling device for cooling cylindrical battery cells for e.g. vehicle with electrical drive, has separate coolant line fastened at monolithic cooling body and thermally conductively contacted with cooling body - Google Patents

Abstract

The device (10) has a monolithic cooling body (14) including a cooling bottom (16), which extends in a plane (18). Holding and cooling bars (20) extend from the plane of the cooling bottom and laterally position cylindrical battery cells (12). A separate coolant line (26) is fastened at the cooling body. The coolant line is thermally conductively contacted with the cooling body. The cooling body is manufactured from aluminum by a die casting method. The cooling bottom includes a coolant line groove (24) on a side, which faces away from the bars. The coolant line is fastened in the coolant line groove by a thermally conductive adhesive i.e. cast resin.

Description

The invention relates to a battery cooling device for battery cells and a battery assembly comprising such a battery cooling device and a plurality of battery cells.

From the DE 10 2006 045 564 A1 For example, a battery cooling device for cylindrical battery cells is known with a flat cooling bottom, to which separate heat conducting body are attached by solder joints. The heat conduction takes place from the side walls of the battery cells via the heat-conducting body to the cooling bottom and a coolant line formed in the cooling bottom. The preparation of such a cooling device is complicated, since a large number of solder joints are necessary, which are arranged directly in the heat flow, whereby the quality of the solder joint on the one hand significantly affects the function of the battery cooling device and on the other hand can lead to high rejection rate by incorrect soldering.

The object of the invention is to provide a battery cooling device, which allows improved heat conduction and can be produced by a simple manufacturing process, and a battery assembly with such a cooling device.

This object is achieved by a battery cooling device for battery cells, in particular for cylindrical battery cells, which comprises at least one monolithic heat sink with a cooling bottom which extends in one plane and holding and cooling webs extending from the plane of the cooling base for laterally positioning the battery cells separate coolant line is provided which is attached to the heat sink and with the heat sink in heat-conducting contact.

The heat conduction within the heat sink is improved because the heat sink is monolithic and no solder joints or interfaces of adjacent components of the heat sink are in the heat flow.

By providing a separate coolant line problems that may occur in the sealing of, for example, formed directly in the heat sink coolant lines can be avoided.

The coolant line can be received in a form-fitting manner in the monolithic heat sink. This allows a maximum contact surface for heat transfer between the coolant line and the heat sink.

Preferably, the coolant line is inserted in the production of the heat sink in a die-casting tool and molded around a positive fit.

Alternatively, it is possible that the cooling base on the side remote from the holding and cooling webs side has a Kühlmittelleitungsnut, which is designed to receive the coolant line. The Kühlmittelleitungsnut allows a recording of the separate coolant line at a subsequent time in the manufacturing process of the battery cooling device and allows, for example, an adaptation to the outer surface of the coolant line.

The coolant line may be secured in the coolant conduit groove by potting a thermally conductive adhesive, preferably a cast resin with heat conductive additives. On the one hand, this makes it possible to fasten the coolant line in the cooling bottom and, on the other hand, improves the heat transfer between the coolant line and the cooling bottom.

It is also possible that a pressure plate is provided, which acts on the coolant line against the cooling bottom. This allows an alternative attachment of the coolant line to the cooling floor and improves the heat transfer between the coolant line and the cooling floor by the coolant line is pressed against the cooling floor and thus a direct contact between the coolant line and the cooling floor is ensured.

A weight reduction of the battery cooling device can be achieved by the hollow bottom and / or the holding and cooling webs of the monolithic heat sink are hollow.

For example, the wall thickness of the heat sink is between 1.5 to 3 mm.

The holding and cooling webs and preferably the cooling bottom can essentially have a constant wall thickness. This is particularly advantageous when producing the monolithic heat sink by die casting, since in this way the die cast part can be injection molded with a short cycle time and the distortion of the diecast part can be reduced.

A particularly compact design of the battery cooling device on a small area can be achieved by arranging the holding and cooling webs so that the battery cells can form a tight package. In such an arrangement, the battery cells adjoin one another directly with their side surfaces, while the holding and cooling webs are arranged in spaces resulting from the geometry of the battery cells. For circular cylindrical battery cells results for example, a hexagonal packing of the battery cells.

Preferably, the monolithic heat sink recesses in the cooling bottom, which are formed as burst openings for the battery cells. In this way, the battery cooling device provides a volume in which defective battery cells can burst due to intended breaking points.

The coolant line may have a tube with preferably circular cross section, in particular with an inner diameter of 2 to 5 mm, preferably from 2.5 to 3.5 mm. This allows a simple design for the separate coolant line.

For example, the coolant line is curved, preferably sinusoidal. In this way, on the one hand, the length of the coolant line is extended in the cooling floor, whereby the heat-transferring contact area between the coolant line and the cooling base is increased, and on the other hand, the course of the coolant line can be adapted to the geometric conditions of the cooling floor.

Preferably, the coolant line is hairpin-shaped. In this way, the return of the coolant in the coolant line takes place in approximately the same area as the forward line of the coolant, whereby an inhomogeneous temperature distribution can be compensated due to the coolant flowing through the coolant line.

It can be provided a plurality of coolant lines. In this way, the length of a single coolant line can be shortened without changing the overall length of the coolant lines. Preferably, a coolant distributor is provided and the coolant lines are connected in parallel.

For example, the coolant distributor and the coolant lines can form a coolant system, which can form a prefabricated structural unit, whereby a simple mounting on the heat sink is made possible.

Preferably, the coolant distributor is arranged in a common component, for example a fastening flange, together with a refrigerant outlet header.

In particular, the coolant distributor is designed as Venturi or dynamic pressure distributor.

A compact design is made possible by providing a mounting flange for the coolant distributor on the heat sink.

The object of the invention is further achieved by a battery assembly with a cooling device described above and a plurality of battery cells, in particular cylindrical battery cells.

Preferably, the holding and cooling webs extend up to half the height, preferably up to one third of the height of the battery cells. In this way, the weight of the cooling device can be reduced, and the cooling device can be arranged at a distance from the electrical terminals of the battery cells.

Preferably, a gap between the holding and cooling webs and the battery cells is filled by a thermally conductive potting compound. In this way, the battery cells can be mounted on the one hand in the battery cooling device, and on the other hand, the heat transfer between the battery cells and the heat sink is improved.

Further features and advantages of the invention will become apparent from the following description and the drawings, to which reference is made. In the drawings show:

1 a schematic sectional view of a battery assembly according to the invention according to a first embodiment;

2 a plan view of a battery assembly according to the first embodiment of the invention;

3 a view of the bottom of the battery assembly 2 ;

4 a side view of the battery assembly according to 3 with an inserted battery cell;

5 a perspective view of the top of a heat sink of the battery cooling device 2 ;

6 a perspective view of the underside of the heat sink 5 ;

7 a coolant line system of a battery cooling device according to the invention;

8th a schematic view of a coolant distributor of the coolant line system 7 ;

9 an exploded view of the battery cooling device according to the first embodiment of the invention;

10 a first process step of manufacturing the battery cooling device according to the first embodiment of the invention;

11 a second process step of manufacturing the battery cooling device according to the first embodiment of the invention;

12 the completed battery cooling device according to the first embodiment of the invention;

13 a schematic sectional view of a battery assembly according to a second embodiment of the invention;

14 a schematic sectional view of a battery assembly according to a third embodiment of the invention;

15 a schematic sectional view of a battery assembly according to a fourth embodiment of the invention;

16 a detail view of a battery cooling device according to the fourth embodiment of the invention;

17 a detail view of the heat sink according to the fourth embodiment of the invention;

18 a perspective view of a cooling body with inserted coolant line of a battery cooling device according to the fourth embodiment of the invention; and

19 a detailed perspective view of the battery cooling device according to the fourth embodiment of the invention.

The following is a battery assembly 100 on the basis of embodiments for vehicle batteries, in particular for vehicles with electric or hybrid drive described.

A schematic view of a battery assembly 100 with a battery cooling device 10 and a plurality of cylindrical, here circular cylindrical battery cells 12 is in 1 shown. For clarity, only a section of the battery assembly 100 with a battery cell 12 shown.

The battery cooler 10 includes a monolithic heat sink 14 with one in a plane 18 extending cooling floor 16 , being the plane 18 in 1 extending horizontally and perpendicular to the plane of the drawing. Out of the plane 18 of the cooling floor 16 extend holding and cooling webs 20 for lateral positioning of the cylindrical battery cells. The holding and cooling bars 20 comprise perpendicular to the plane of the cooling floor 16 extending wall portions that are formed to on the side surfaces of the battery cells 12 to be able to lie.

The holding and cooling bars 20 are arranged so that they have a battery cell receptacle 22 for a battery cell 12 form. The battery cells 12 and the holding and cooling bars 20 are each formed so that a good heat transfer between the side surfaces of the battery cells and the wall portions of the holding and cooling webs 20 is possible.

The cooling floor 16 points to the of the holding and cooling bars 20 opposite side a Kühlmittelleitungsnut 24 on which for receiving a coolant line 26 is trained. The coolant line 26 is one of the monolithic heat sink 14 separate component. In the in 1 shown portion of the battery cooling device 10 are two coolant line grooves 24 and coolant lines inserted therein 26 intended.

For fixing the coolant lines 26 on the monolithic heat sink 14 is a pressure plate 28 intended. The pressure plate 28 is on the of the holding and cooling bars 20 opposite side of the cooling floor 16 arranged and acts on the coolant lines 26 against the cooling floor 16 , By the coolant pipes 26 against the cooling floor 16 be applied, a direct contact between the coolant lines 26 and the cooling floor 16 ensures heat transfer.

The pressure plate 28 is by fasteners 30 on the cooling floor 16 attached. In the embodiment shown, the fastening elements 30 Rivet extensions of the monolithic heat sink 14 extending through corresponding recesses in the pressure plate 28 extend and plastically deformed at its free end to form a lock.

The coolant line grooves 24 are in their geometry of the outer surface of the coolant lines 26 adapted to provide a large common surface for heat transfer. The coolant lines 26 are tubes of circular cross-section having an inner diameter of 2 to 5 mm and preferably of 2.5 to 3.5 mm. However, other cross-sectional shapes and sizes may be provided.

2 shows a plan view of the battery assembly 100 , The battery assembly 100 includes 35 circular cylindrical trained battery cells 12 , Which are arranged in five rows, each with seven battery cells, the battery cell rows are each offset by half a battery cell, whereby the battery cells 12 arranged in a hexagonal pattern and each battery cell 12 , except at the edge of the battery assembly 100 arranged battery cells 12 , each of six adjacent battery cells 12 is surrounded. The result is a dense packing in which cells extend into the V-shaped spaces between batteries of the adjacent row.

Electrical connections 32 the battery cells 12 are at the of the heat sink 14 remote end faces of the battery cells 12 arranged.

At the side edge of the battery assembly 100 indicates the monolithic heat sink 14 the battery cooling device 10 a holding and cooling wall 21 on, which in their function the holding and cooling bars 20 equivalent. The holding and cooling wall 21 is designed as a closed wall that extends around the entire perimeter of the battery assembly 100 extends.

The battery cells 12 are densely packed, so that the side walls of adjacent battery cells 12 essentially abut each other. Due to the hexagonal arrangement of the battery cells is between each three adjacent battery cells 12 a gap formed. In these spaces are the holding and cooling bars 20 arranged, each having three contact surfaces for each battery cell 12 exhibit. In this way, an arrangement of the battery cells 12 on a minimum area allows.

The contact surfaces of the holding and cooling webs 20 and the holding and cooling wall 21 are to the geometries of the side walls of the battery cells 12 adapted and thus allow a large contact surface for heat transfer.

The battery cell shots 22 be through the holding and cooling bars 20 as well as at the edge of the battery cells 12 through the holding and cooling webs 20 as well as the holding and cooling wall 21 educated.

3 shows a view of the bottom of the battery assembly 100 , wherein the pressure plate 28 and the coolant lines 26 are removed. In the cooling floor 16 is a plurality of recesses 34 provided, which are circular and extending through the entire cooling floor 16 extend through. It is each a recess 34 a battery cell receptacle 22 assigned. The recesses 34 are as burst openings for the battery cells 12 formed, whereby the battery cooling device 10 provides a volume into which defective battery cells 12 can burst open on their front pages by envisaged predetermined breaking points.

In the embodiment shown, there are three separate coolant line grooves 24 provided, each hairpin-shaped around a series of battery cells 12 run. Through the hairpin shape of the coolant line grooves 24 and coolant lines 26 the supply and return of the coolant takes place in adjacent areas of the monolithic heat sink 14 so that also along with the coolant line 26 heating coolant a substantially homogeneous temperature distribution in the heat sink 14 results.

The coolant line groove 24 runs sinusoidally curved between the recesses 34 adjacent rows of battery cell receptacles 22 , The curved course of Kühlmittelleitungsnuten 24 is on the one hand by the geometry of the cooling floor 16 , in particular the recesses 34 , predetermined, but on the other hand also allows an enlargement of the contact surfaces between the cooling floor 16 and the coolant lines 26 , as the length of the coolant lines 26 increased in a curved course against a straight line, whereby the contact surface between the coolant lines 26 and the cooling floor 16 is enlarged.

There may be other courses of Kühlmittelleitungsnuten 24 be provided, for example, must the Kühlmittelleitungsnut 24 Do not run along a series of battery seats, or it may be a geometry of the cooling floor 16 can be chosen, the a straight line of the Kühlmittelleitungsnuten 24 allows, for example, the recesses 34 have a smaller radius.

A plurality of fasteners 30 is in particular between adjacent battery cell receptacles 22 a series of battery cell receptacles 22 intended.

4 shows a side view of the battery assembly 100 out 3 , for the sake of clarity, only a single battery cell 12 is shown. The height h of the holding and cooling wall 21 is between one third and one half of the height H of the battery cells 12 ,

The height of the holding and cooling bars 20 and the holding and cooling wall 21 that is the distance that the holding and cooling bars are 20 or the holding and cooling wall 21 from the cooling floor 16 extend is substantially the same in the embodiment shown.

The monolithic heat sink 14 also has a mounting flange 36 for securing a coolant connection or a coolant distributor for the coolant lines 26 is provided.

5 shows a perspective view of the top of the monolithic heat sink 14 , The battery cell shots 22 be in the edge region of the monolithic heat sink 14 through the holding and cooling webs 20 and the holding and cooling wall 21 laterally limited. The inner battery cell receptacles 22 be through the holding and cooling bars 20 laterally limited. The cooling floor 16 limits the lower end of the battery cell receptacles 22 , each battery cell recording 22 a recess 34 is assigned as a burst opening.

An optimized heat transfer between the battery cells 12 and the monolithic heat sink 14 can be achieved by the space between the holding and cooling bars 20 or the holding and cooling wall 21 and the battery cells 12 is filled by a heat-conductive potting compound. In this way, the formation of heat-insulating gaps between the heat sink 14 and the battery cells 12 prevented. The potting can be done easily because the battery cells 12 the recesses 34 in the cooling floor 16 close and the closed retaining and cooling wall 21 prevents lateral leakage of the potting compound in the liquid state. Since the height h of the holding and cooling webs 20 or the holding and cooling wall 21 does not extend over the entire height H of the battery cells, the risk is reduced that the potting compound with the electrical connections of the battery cells 12 comes into contact.

6 shows a perspective view of the underside of the monolithic heat sink 14 , the opposite 5 is shown rotated by 180 °. The cooling floor 16 has the Kühlmittelleitungsnuten 24 , the recesses 34 and the fasteners 30 for the pressure plate 28 on. Furthermore, the cooling floor has 16 in its edge region on a circumferential wall, which is substantially the height of the pressure plate 28 corresponds and which through outlet openings of Kühlmittelleitungsnuten 24 is interrupted. There are attachment points for attaching the battery cooling device 10 provided in a vehicle.

The monolithic heat sink 14 is made by die casting from aluminum. But it can also be other manufacturing processes and / or materials for the monolithic heat sink 14 be used. Preferably, the monolithic heat sink 14 manufactured by die casting, without subsequent process steps, such as milling the Kühlmittelleitungsnuten 24 are necessary.

In the first embodiment, the monolithic heat sink is 14 solidly formed.

7 shows a coolant line system 38 with three parallel coolant lines 26 and a coolant distributor 40 , the coolant connections 42 for a coolant system, for example the air conditioning system of a vehicle. It can be provided liquid or phase-changing coolant.

The coolant distributor 40 Allows the distribution of the coolant to three parallel coolant lines 26 , which each run hairpin-shaped. The coolant distributor 40 also has a common return of the three coolant lines 26 on.

The common return is formed by a common outlet chamber, which communicates fluidically with the three parallel-connected coolant lines.

The coolant line system 38 forms a prefabricated unit attached to the monolithic heat sink 14 can be attached. Alternatively, it is possible for the coolant distributor 38 in a mounting flange of the heat sink 14 is trained.

8th shows a detailed view of the coolant distributor 40 with a coolant connection 42 , which has an inlet chamber with a coolant nozzle 44 and a distribution chamber 46 , from which the three coolant lines 26 extend. The coolant lines 26 are arranged so that they each at right angles to the direction of flow of the coolant into the distribution chamber 46 are arranged.

When operating the battery cooling device 10 the coolant flows through the coolant nozzle 44 into the distribution chamber 46 and will be in the distribution chamber 46 mixed, with a good mixing of the phases is made possible especially in mixed-phase coolants.

9 shows an exploded view of the battery cooling device 10 with the monolithic heat sink 14 , the coolant line system 38 with the coolant distributor 40 and the three coolant lines 26 as well as the pressure plate 28 ,

The installation of the battery cooling device 10 will be described below on the basis of 10 to 12 explained. In a first step, the coolant lines 26 in the respective Kühlmittelleitungsnuten 24 inserted. The coolant distributor 40 is on the mounting flange 36 attached.

The pressure plate is placed on the monolithic heat sink 14 with the mounted coolant line system 38 applied, with the fasteners 30 through the recesses provided for this purpose on the pressure plate 28 extend.

In the pressure plate 28 are also recesses 34 provided in the assembled state with the recesses 34 of the cooling floor 16 aligned and common bursting openings for the battery cells 12 form.

Subsequently, the pressure plate 28 through the fasteners 30 on the cooling floor 16 of the monolithic heat sink 14 attached, with the coolant lines 26 against the cooling floor 16 be applied, whereby a good heat-conducting contact between the coolant lines 26 and the cooling floor 16 is guaranteed.

13 shows a second embodiment of the battery cooling device 10 with an alternative attachment of the coolant line 26 on the cooling floor 16 , The coolant line 26 is analogous to the first embodiment in a Kühlmittelleitungsnut 24 inserted. The coolant line groove 24 is with a thermally conductive adhesive 48 poured out, whereby on the one hand the heat transfer between the coolant line 26 and the cooling floor 16 is improved and on the other hand, the attachment of the coolant line 26 by means of the heat-conductive adhesive 48 on the cooling floor 16 is possible.

The second embodiment may in particular also with a pressure plate 28 be combined according to the first embodiment.

Another alternative attachment of the separate coolant line 26 in monolithic heat sink 14 is in 14 shown. The coolant lines 26 are positively in the monolithic heat sink 14 added. In the manufacture of the third embodiment, the coolant lines 26 in the manufacture of the monolithic heat sink 14 inserted into the die-casting tool so that the coolant lines 26 be molded positively during die casting.

15 shows a schematic view of a fourth embodiment of the battery cooling device 10 , The monolithic heat sink 14 includes a cooling floor 16 and holding and cooling bars 20 , which are each hollow. They are cavities 50 in the holding and cooling bars 20 and cavities 52 in the cooling floor 16 provided, which of the Kühlmittelleitungsnut 24 be disconnected or connected to this. Through the cavities 50 . 52 becomes the weight of the monolithic heat sink 14 reduced. Another advantage results from a faster cycle time in a production of the monolithic heat sink 14 by die casting.

The features of the fourth embodiment may also be combined with the specific features of the first three embodiments.

The monolithic heat sink out 15 is designed so that the holding and cooling webs 20 and the cooling floor 16 have a substantially constant wall thickness, which is between 1.5 and 3 mm.

It is also possible that the wall thickness of the holding and cooling bars 20 or the cooling floor 16 vary, preferably to obtain an optimization of heat transfer surfaces, wherein the wall thicknesses of the heat sink 14 preferably between 1.5 and 3 mm.

16 shows an alternative embodiment of a fastener 30 , being at the cooling floor 16 a recess is provided with a thread into which a screw 54 for fastening the pressure plate 28 is screwed in. There may also be other suitable fasteners 30 be provided.

16 further shows an alternative embodiment of the coolant line groove 24 , which has a chamfer, whereby the insertion of the coolant line 26 is simplified during assembly.

17 shows a detailed view of a monolithic heat sink 14 according to the fourth embodiment, wherein the Kühlmittelleitungsnut 24 with the cavities 50 . 52 in the cooling floor 16 and in the holding and cooling bars 20 is connected and forms a common cavity, whereby an optimal material and weight saving is made possible.

18 shows a detailed view of the battery cooling device 10 with two sections of a coolant line 26 , which into the Kühlmittelleitungsnut 24 is inserted.

19 shows the battery cooling device 10 according to 17 and 18 with on the heat sink 14 mounted coolant line system 38 and a pressure plate 28 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006045564 A1 [0002]

Claims (15)

Battery cooling device ( 10 ) for battery cells ( 12 ), in particular cylindrical battery cells, comprising a monolithic heat sink ( 14 ) with one in a plane ( 18 ) cooling bottom ( 16 ) and out of the plane ( 18 ) of the cooling floor ( 16 ) extending holding and cooling webs ( 20 ) for lateral positioning of the battery cells ( 12 ), with a separate coolant line ( 26 ) is provided, which on the heat sink ( 14 ) and with the heat sink ( 14 ) is in heat-conducting contact. Battery cooling device according to claim 1, wherein the heat sink ( 14 ) is made by die casting, preferably of aluminum. Battery cooling device according to claim 1 or 2, wherein the coolant line ( 26 ) in the monolithic heat sink ( 14 ) is recorded. Battery cooling device according to claim 1 or 2, wherein the cooling bottom ( 16 ) on the of the holding and cooling bars ( 20 ) facing away from a Kühlleielleitungsnut ( 24 ), which for receiving the coolant line ( 26 ) is trained. Battery cooling device according to claim 4, wherein the coolant line in the Kühlleielleitungsnut ( 24 ) by casting a thermally conductive adhesive ( 48 ), preferably a casting resin with heat-conducting additives, is attached. Battery cooling device according to claim 3 or 4, wherein a pressure plate is provided which the coolant line ( 26 ) against the cooling floor ( 16 ). Battery cooling device according to one of the preceding claims, wherein the cooling bottom ( 16 ) and / or the holding and cooling webs ( 20 ) of the monolithic heat sink ( 14 ) are hollow. Battery cooling device according to one of the preceding claims, wherein the holding and cooling webs ( 20 ) and preferably the cooling floor ( 16 ) have a substantially constant wall thickness. Battery cooling device according to one of the preceding claims, wherein the holding and cooling webs ( 20 ) are arranged so that the battery cells ( 12 ) can form a tight package. Battery cooling device according to one of the preceding claims, wherein the monolithic heat sink ( 14 ) Recesses in the cooling bottom ( 16 ), which serve as burst openings for the battery cells ( 12 ) are formed. Battery cooling device according to one of the preceding claims, wherein a plurality of parallel coolant lines ( 26 ) are provided, each communicating fluidly with an inlet and outlet chamber, preferably in a common component. Battery cooling device according to claim 11, wherein the inlet chamber is designed as a refrigerant distributor, preferably as a dynamic pressure distributor or Venturiverteiler. Battery assembly ( 100 ) with a battery cooling device ( 10 ) according to one of the preceding claims and a plurality of battery cells ( 12 ), in particular cylindrical battery cells. Battery assembly according to claim 11, wherein the holding and cooling webs ( 20 ) up to half the height, preferably up to one third of the height of the battery cells ( 12 ). Battery assembly according to claim 11 or 12, wherein a gap between the holding and cooling webs ( 20 ) and the battery cells ( 12 ) is filled by a heat conductive potting compound.

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