DE102019212864B3 - Cooling device for cooling a vehicle battery, a vehicle battery and a motor vehicle with a vehicle battery - Google Patents

Abstract

The invention relates to a cooling device (16) for cooling a vehicle battery (10) which has at least two battery modules. The cooling device comprises a base plate (18), the base plate (18) having a channel structure (20) in a first area (38) and a second area (40) on a side facing the vehicle battery, the first area (38) for Cooling of a first battery module (13) and the second area (40) for cooling a second battery module (14) is arranged. The channel structure (20) is covered by a channel element (22), so that a part of the channel element (22) together with the channel structure (20) forms a cooling channel through which a coolant can flow, the channel element (22) being designed to close Spread through the flow of the coolant and wherein a return channel (44) of the cooling channel of the second area is formed spatially isolated from the cooling channel of the first area.

Description

The invention relates to a cooling device for cooling a vehicle battery, which has at least two battery modules, a vehicle battery with at least two battery modules and a cooling device, and a motor vehicle with such a vehicle battery.

A vehicle battery, in particular a traction battery in an electric vehicle, is tempered in most cases with a cooling device that has a metallic cooling plate through which liquid coolants, such as water-glycol mixtures, are passed. In order to compensate for tolerances between the vehicle battery and a cooling device, a heat-conducting medium, a so-called gap filler, is usually applied between the vehicle battery and the cooling device, which represents an additional process step and significantly worsens recyclability, since the gap filler also affects the cooling device the vehicle battery is partially glued. In addition, the gap filler represents a high cost factor in the manufacture of the vehicle battery.

From the DE 10 2006 059 989 A1 an arrangement for cooling a battery consisting of a plurality of individual cells is known, the individual cells being thermally contacted to a base plate via cooling elements, the base plate being cooled by means of a flowing cooling medium.

From the DE 10 2014 119 364 A1 For example, an electric vehicle battery pack is known wherein a thermal device is in thermally conductive contact with upper cell surfaces of the assembly.

From the DE 10 2015 216 029 A1 a battery pack with at least one battery cell and a cooling system for cooling the at least one battery cell are known. The cooling system comprises a cooling plate which is arranged outside the housing, wherein the at least one cooling plate lies flat against a cover plate of the housing, and heat is dissipated from the at least one battery cell through the cover plate to the cooling plate.

From the DE 10 2011 075 820 A1 a traction battery consisting of a housing and at least one arrangement of electrochemical cells located in the housing and at least one temperature control device through which a fluid can flow is known.

From the DE 10 2015 115 875 A1 A cooling system for controlling the temperature of a motor vehicle battery is known, with a base plate to form a flat storage shelf for battery modules of the motor vehicle battery, a strike plate connected to the base plate, the strike plate having channel channels and the channel channels together with an underside of the floor plate each have a cooling channel for the passage of a cooling medium form and a separating plate arranged between the bottom plate and the strike plate to separate a flow collecting line from a return collecting line.

From the DE 10 2015 108 611 A1 a vehicle component for an electrically operated vehicle and a method for operating such a vehicle component are known.

The object of the present invention is to increase the efficiency of a cooling device.

The object is achieved by the subjects of the independent claims. Advantageous developments of the invention are disclosed by the dependent claims, the following description and the figures.

The invention provides a cooling device for cooling a vehicle battery, the vehicle battery having at least two battery modules. The cooling device has a base plate, the base plate having a channel structure in a first area and a second area on a side facing the vehicle battery, the first area being arranged for cooling a first battery module and the second area being arranged for cooling a second battery module. The channel structure is covered by a channel element, so that part of the channel element together with the channel structure forms a cooling channel through which a coolant can flow, the channel element being designed to expand when the coolant flows through. The cooling channel of the first area and the cooling channel of the second area are fed by a common coolant inlet, a return channel of the cooling channel of the second area being spatially isolated from the cooling channel of the first area.

In other words, the cooling device comprises a base plate on which recesses are provided which form a channel structure. The channel structure can be produced, for example, by embossing or milling out material from the base plate. However, it is also possible for the channel structure to be produced during the production of the base plate, for example in a 3D printing process or an injection molding process. The channel structure can be present at least in a first area and a second area of the base plate, the areas for cooling the respective Battery module are provided. For this purpose, each area can have a meandering channel structure that can cover a base area of the respective battery module. In the direction of the respective battery module, the channel structure can be covered by a channel element, the channel structure together with the channel element forming a cooling channel through which a coolant can flow. A fluid such as water or a water-glycol mixture is particularly suitable as the coolant.

When the coolant flows through the cooling channel, it is preferably provided that the channel element spreads and / or expands in the direction of the battery module. This means that the channel element can be elastically deformed. The channel element can in particular comprise a film made of plastic or a metal which is impermeable to water and has a high coefficient of thermal conductivity. The channel element can, for example, also be a semicircular tube, in particular an elastic rubber tube, which expands under pressure in the direction of the respective battery module. It can thus be achieved that a tolerance-related gap between the cooling device and the respective battery module of the vehicle battery can be bridged without a heat-conducting medium, such as a gap filler, having to be introduced between the cooling device and the vehicle battery. This means that when the coolant flows through the channel element expands to the respective battery module and adapts to an underside of the battery module, so that a flat or form-fitting contact is created between the channel element and the battery module. This can then be used to transfer heat from the battery module to the coolant in the cooling duct. As a result, there is the advantage that tolerance fluctuations can be compensated for and that the expensive gap filler can be dispensed with. In contrast to conventional structures, recyclability can also be fully guaranteed, since the battery modules do not have to be glued to the cooling device.

Furthermore, the cooling channel of the first area and the second area are fed by a common coolant inlet, whereby additional connections for the coolant inlet of the respective area can be saved. Furthermore, a return channel of the cooling channel of the second area is designed to be spatially isolated from the cooling channel of the first area. It can thus be avoided that the return channel of the second area, the coolant of which can have a higher temperature than the coolant in the cooling channel of the first area, heats up the coolant in the first area and thus deteriorates a cooling performance.

The return channel of the second area can preferably be routed past the channel structure of the first area. It can particularly preferably be provided that the return duct of the second area runs on a plane that is remote from the cooling duct of the first area. The invention has the advantage that efficiency can be increased through the insulation of the return duct of the second area, since the cooling ducts do not mutually warm up.

The invention also includes embodiments which result in additional advantages.

One embodiment provides that the base plate has a return structure in the first area on a side facing away from the vehicle battery, which is covered by the channel element and, together with the return structure, forms the return channel of the cooling channel of the second area, the base plate from the cooling channel to the second area the return channel of the second area has a penetration through the base plate. In other words, the spatial isolation of the return channel of the second area is achieved in that the return channel of the second area is arranged on the opposite side of the base plate, the return channel being formed by a return structure in the base plate, which is formed by the channel element that is located at Can expand through the flow of coolant is covered. The return channel structure can be incorporated into the base plate in the same way as the channel structure and form a recess in the base plate. A connection from the cooling channel of the second area, which is located on the side facing the battery module, to the return channel of the second area, which is located on the side facing away from the battery module, can be created by penetrating the base plate. The penetration can, for example, be a bore or recess through the base plate. This embodiment has the advantage that the return channel of the second area can easily be spatially isolated from the cooling channel of the first area without the need to use additional lines and connections. With this embodiment, the efficiency of the cooling device can be increased.

It is preferably provided that the return channel of the second area is arranged below a return channel of the first area. In other words, the first area can have its own return channel which runs on the side facing the vehicle battery, the return channel of the second area being arranged on the side facing away from the vehicle battery below the return channel of the first area. This has the advantage that connections for the respective return duct can be arranged at the same position of the cooling device, whereby a space requirement for the cooling device can be reduced.

In an advantageous embodiment it is provided that the base plate has a heat-insulating intermediate floor between the first area and the return duct of the second area. The heat-insulating intermediate floor can, for example, be formed from the same material as the base plate and have a heat-insulating effect. For example, between the return channels of the first and second area, the intermediate floor can be designed as a web of, for example, 1.5 mm high, which spatially separates the return channels and has a heat-insulating effect. In particular, the intermediate floor can be formed from plastic, the height of the intermediate floor being selected such that no or only a small amount of heat is transferred from the return duct of the second area into the duct structure of the first area. It can also be provided that a heat-insulating material with a low coefficient of thermal conductivity is incorporated in the intermediate floor, as a result of which heat transfer can be reduced. For example, a ceramic, a plastic foam and / or a glass fiber composite material can be used as the heat insulating material. This embodiment has the advantage that a heat transfer between the return duct of the second area and the duct structure of the first area can be reduced, which increases the efficiency of the cooling device.

One embodiment provides that the base plate and the intermediate floor are formed from a one-piece plastic element. The one-piece plastic element can be produced, for example, by an injection molding process or a 3D printing process. This embodiment has the advantage that the base plate and the intermediate floor can be produced easily reproducibly, whereby costs in the production of the cooling device can be saved.

One embodiment provides that the channel element is designed as a film that covers the channel structure and the return channel structure, and that is made of an elastically stretchable plastic or an elastically stretchable hybrid film, the film being gas-tightly connected to the base plate. In other words, the channel element can be an elastically stretchable plastic film or an elastically stretchable hybrid film which, for example, has a wall thickness of 0.05 mm to 0.5 mm. The film can spread in particular when the coolant flows through the cooling channel, as a result of which the film can nestle against an outer surface of the battery module. Thus, a tolerance between the cooling device and the vehicle battery can be compensated for. In addition, by spreading the film on the battery module of the vehicle battery, a flat contact can be made, through which an effective heat transport is possible. A hybrid film can in particular be a film with several intermediate layers, preferably a multi-layer composite film which can be impermeable to water and can have high impact strength and a high coefficient of thermal conductivity. For example, the hybrid film can comprise plastics such as polypropylene and polyethylene. The gas-tight connection of the film to the base plate can be carried out, for example, by gluing or welding the film to the base plate. This embodiment has the advantage that a cost-effective material for bridging tolerances and transferring heat can be provided.

Another embodiment provides that a connection for the coolant inlet and a connection for the return ducts of the first and second areas are integrated into the base plate. This means that connections, in particular connections of the coolant, are provided on the base plate. For example, plug connections or screw connections for coolant hoses can be integrated into the base plate. Furthermore, recesses for assembly, in particular screw threads or recesses for bolts, can be integrated into the base plate in order to facilitate assembly with the vehicle battery. This embodiment has the advantage that connecting means for connections to the base plate can be saved, which reduces costs. The probability of failure of the cooling device due to leaks can also be minimized, since fewer components are used that could potentially leak.

Another aspect of the invention relates to a vehicle battery with at least two battery modules and with a cooling device according to one of the preceding embodiments. This results in the same advantages and possible variations as with the cooling device.

One embodiment of the vehicle battery provides that the channel element of the return channel of the second region is in contact with a battery housing bottom when the coolant flows through the return channel and is designed to transfer heat, the battery housing bottom being designed to cool the coolant in the return channel . In other words, the channel element of the return channel can spread out so that it is on a Battery housing bottom rests, whereby heat can be transferred between the coolant of the return channel and the battery housing bottom. The battery housing bottom can in particular have a heat exchanger function in that the coolant of the return duct of the second region is cooled. The battery housing bottom can preferably be a metallic battery housing bottom, through which heat can be transported away and distributed. This embodiment has the advantage that the battery housing bottom draws heat from the warm coolant, which contributes to an increase in the efficiency of cooling the vehicle battery.

According to the invention, a motor vehicle with a vehicle battery according to one of the preceding embodiments is also provided. The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger vehicle or truck, or as a passenger bus or motorcycle.

The invention also includes further developments of the method according to the invention which have features such as have already been described in connection with the further developments of the motor vehicle according to the invention. For this reason, the corresponding developments of the method according to the invention are not described again here.

The invention also includes the combinations of the features of the described embodiments.

• 1 eine schematische Seitenansicht einer Fahrzeugbatterie mit einer Kühlvorrichtung gemäß einer beispielshaften Ausführungsform;
• 2 eine schematische Draufsicht auf eine Kühlvorrichtung gemäß einer beispielhaften Ausführungsform;
• 3 eine schematische Draufsicht einer Kühlvorrichtung gemäß einer weiteren beispielhaften Ausführungsform;
• 4 eine schematische Perspektivansicht einer Durchdringung durch eine Grundplatte einer Kühlvorrichtung gemäß einer beispielhaften Ausführungsform.

Exemplary embodiments of the invention are described below. This shows:

• 1 a schematic side view of a vehicle battery with a cooling device according to an exemplary embodiment;
• 2 a schematic plan view of a cooling device according to an exemplary embodiment;
• 3 a schematic top view of a cooling device according to a further exemplary embodiment;
• 4th a schematic perspective view of a penetration through a base plate of a cooling device according to an exemplary embodiment.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that also develop the invention independently of one another. Therefore, the disclosure is intended to include combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

In the figures, the same reference symbols denote functionally identical elements.

In 1 is a vehicle battery 10 shown schematically according to an exemplary embodiment. The vehicle battery 10 can be in a motor vehicle 12th located, the motor vehicle 12th is only indicated schematically in this figure. The motor vehicle can preferably 12th be an electrically powered motor vehicle, and the vehicle battery 10 can be a traction battery of the motor vehicle 12th be.

The vehicle battery 10 can in this embodiment two battery modules, a first battery module 13 and a second battery module 14th each of the battery modules 13 , 14th can be constructed from a plurality of battery cells. For cooling the battery modules 13 , 14th can the vehicle battery 10 furthermore a cooling device 16 exhibit.

The cooler 16 can be a base plate 18th include, on one of the battery modules 13 , 14th facing side of the base plate a channel structure 20th in the base plate 18th is incorporated. That means the base plate 18th can have recesses on a side facing the battery modules, through which a channel structure is formed.

It can preferably be provided that the channel structure 20th into a first area for the first battery module 13 and into a second area for the second battery module 14th divides. The channel structure 20th that is located in the first area can be on a surface of the base plate 18th below a first battery module 13 be arranged, and the channel structure 20th the second area can be on a surface of the base plate 18th below the second battery module 14th be arranged. Thus, each of the two battery modules 13 , 14th have their own channel structure or their own cooling circuit.

The channel structure 20th can also be from a duct element 22nd be covered, the channel element 22nd is preferably designed as a film which comprises an elastically stretchable plastic or an elastically stretchable hybrid film. An elastically stretchable hybrid film can be a multilayer composite film made of different plastics, material properties of can constructively complement different layers of the hybrid film. Alternatively, a metal foil which can expand under pressure can also be provided as the foil. A thin sheet of aluminum can be used particularly suitably as a foil.

The film is advantageous 22nd gastight with the base plate 18th connected so that the channel structure 20th with the foil 22nd forms a cooling channel. In other words, the cooling channel becomes unidirectional from the channel structure 20th limited in the base plate and in the other direction by the film 22nd .

The foil 22nd can preferably be designed to be in the direction of the battery modules 13 , 14th to spread and / or to expand when the cooling channel is flowed through by a coolant. This means that a higher pressure can arise within the cooling channel when the coolant flows through it, causing the film to move in the direction of the battery modules 13 , 14th can spread and / or expand elastically. As a result of this expansion in the direction of the battery modules, a tolerance, that is to say a gap, can be created between the cooling device 16 and the battery modules 13 , 14th can be bridged without an additional use of a heat transfer medium as a gap filler is necessary.

The cooling channel of the first area and of the second area can particularly preferably come from a common coolant inlet 24 are fed, whereby additional connections as coolant supply can be saved. For a return of the coolant it can be provided in an advantageous manner that each area of the respective battery modules 13 , 14th has its own return, in particular the return of the second area spatially isolated from the channel structure 20th of the first area runs so that no heat is transferred from the warm coolant in the return into the cooling circuit of the first area.

For this purpose it can be provided in particular that in the base plate 18th on one of the vehicle's batteries 10 facing away from a return structure 26th is provided, which in turn with the channel element 22nd , that means for example with the foil 22nd , is covered, so that a return channel of the second region through which coolant can flow is formed. The return structure 26th can according to the channel structure 20th a recess in the base plate 18th be, and the slide 22nd can be gastight with the return structure 26th be covered.

In order to achieve spatial isolation of the return duct of the second area, a penetration 28 in the base plate 18th provided that connects the cooling channel of the second area with the associated return channel. The penetration 28 can for example be a recess from a top to a bottom of the base plate, through which the cooling channel of the second area is connected to the return channel of the second area.

The return channel of the second area can preferably be arranged under a return channel of the first area, the return channel of the first area preferably on the side of the base plate facing the battery module 18th runs. This means that a two-storey return system can be provided, the return duct of the first area being on the same level as the duct structure 20th can be located and the return channel of the second area is arranged below this.

An intermediate floor can be installed between the return channels 30th be provided, which is in particular heat-insulating, so that no heat is exchanged between the return channels. The intermediate floor 30th be preferably made of a plastic. The base plate and the intermediate floor are particularly preferably manufactured in one piece from a plastic, for example by means of an injection molding process. It can also be provided here that a connection for the coolant inlet 32 and a connection for the return ducts 34 of the first and second areas of the battery modules 13 , 14th in the base plate 18th are integrated. Recesses for assembly, for example screw threads, can also be provided in the base plate.

For a further increase in the efficiency of the cooling device 16 It can additionally be provided that the return channel of the second region comes into contact with a battery housing base when the coolant flows through 36 stands. This contact can be established, for example, that the film 22nd the return structure expands when the coolant flows through the return channel. The bottom of the battery case 36 can be made of a metallic material so that the heat can be distributed over it and is thus withdrawn from the return channel of the second area.

In 2 Figure 3 is a schematic plan view of a cooling device 16 , especially on a base plate 18th the cooling device shown.

The base plate 18th can be a channel structure 20th have which meander in a first area 38 and a second area 40 runs. The channel structure 20th in the first area 38 can be arranged for this purpose, the first battery module 13 (not shown in this figure) to cool, and the channel structure 20th in the second area 40 can be designed for this purpose, the second battery module 14th (not shown in this figure) to cool. On the channel structure 20th , that is, parallel to the image plane, the film can 22nd (not shown in this figure).

Preferably the first area 38 and the second area 40 through the same coolant supply 24 be supplied with coolant, whereby the channel structure 20th at a turnout area 42 in the two areas 38 , 40 can divide. After going through the channel structure 20th of the respective area, the coolant can flow through a respective return channel 44 via the connection of the return ducts 34 for example, be fed to a heat exchanger.

Preferably, the return channels 44 about the penetration 28 be spatially isolated by directing the return duct of the second area to a lower level and thus the return ducts 44 in two spatially isolated levels to the connection of the return ducts 34 so that no heat between the return ducts 44 is transmitted.

In 3 Figure 3 is a further schematic plan view of a cooling device 16 shown according to a further exemplary embodiment. In this exemplary embodiment, the cooling device 16 be designed to cool three battery modules, the base plate 18th a channel structure 20th for the first area 38 , the second area 40 and a third area 46 having. The channel structure 20th can run according to the course shown for the respective area, with a return channel of the second area 40 and the third area 46 through the penetration 28 on a level below the channel structure 20th of the first area 38 from where the return channel is then below the first area 38 can be directed to a coolant drain.

In 4th is the penetration 28 the base plate 18th out 3 shown in a schematic perspective view according to an exemplary embodiment. For example, this can result in a return 48 of the third area and a return 50 of the second area at the penetration 28 meet through a slit-shaped opening through the base plate 18th can be formed therethrough. Thus, the respective returns in the return channel are passed under the channel structure of the first area.

The cooler 16 can be expanded to further battery modules according to this scheme and is not limited to the exemplary embodiments shown here with two battery modules or three battery modules.

In another exemplary embodiment, one aspect is to provide an active inflatable cooling system that clings to battery cells of a battery module by means of fluid pressure. This cooler 16 is equipped with the help of a two-tier return system, which is through a metallic battery housing base 36 also works like a heat exchanger, since the colder battery housing base can extract heat from the warm fluid of the coolant. This cooling contributes to a further increase in the efficiency of the vehicle battery 10 at.

There is also an intermediate floor 30th , which between the return ducts 44 Has an insulating effect, since plastic is used and through which the fluid of the coolant in the first area 38 not from the fluid of the coolant of the second region 40 is heated. This also means that this insulation is provided by the intermediate floor 30th the efficiency further increased.

Through the design of the cooling device 16 cheap, space-saving and thus efficient battery temperature control is guaranteed. Further advantages are that a very expensive gap filler can be dispensed with, that tolerance fluctuations can be compensated for, that the efficiency of the cooling device is achieved through a heat exchanger function with the battery housing base 36 can be increased and that efficiency can be increased through the isolation of the separate return flows, since the return flows of the coolant do not warm up each other. Furthermore, with this structure, recyclability can be ensured as the cooling device 16 not with the battery modules 13 , 14th is glued. Thus, the battery modules 13 , 14th continue to be used.

Overall, the examples show how the invention can provide an active cooling system for a battery-operated electric vehicle with an integrated return line and a heat exchanger.

Claims (10)

Cooling device (16) for cooling a vehicle battery (10), which has at least two battery modules, with - a base plate (18), the base plate (18) having a channel structure (20) in a first area (38) on a side facing the vehicle battery and a second area (40), wherein the first area (38) is arranged for cooling a first battery module (13) and the second area (40) is arranged for cooling a second battery module (14); - wherein the channel structure (20) is covered by a channel element (22), so that part of the channel element (22) together with the channel structure (20) forms a cooling channel through which a coolant can flow, the channel element (22) being designed to expand when the coolant flows through; - wherein the cooling channel of the first area and the second area are fed by a common coolant inlet (24) and wherein a return channel (44) of the cooling channel of the second area is formed spatially isolated from the cooling channel of the first area. Cooling device (16) after Claim 1 , wherein the base plate (18) in the first area (38) on a side facing away from the vehicle battery has a return structure (26) which is covered by the channel element (22), and together with the return structure (26) the return channel (44) of the Forms the cooling channel of the second area, the base plate (18) having a penetration (28) through the base plate (18) from the cooling channel of the second area to the return channel of the second area. Cooling device (16) after Claim 2 wherein the return channel of the second area is arranged below a return channel of the first area. Cooling device (16) after Claim 2 or 3 wherein the base plate (18) has a heat-insulating intermediate floor (30) between the first area and the return duct of the second area. Cooling device (16) after Claim 4 , wherein the base plate (18) and the intermediate floor (30) are formed from a one-piece plastic element. Cooling device (16) according to one of the preceding claims, wherein the channel element (22) is designed as a film which covers the channel structure (22) and the return structure (26), and which is formed from an elastically stretchable plastic or an elastically stretchable hybrid film , wherein the film is gas-tightly connected to the base plate. Cooling device (16) according to one of the preceding claims, wherein a connection of the coolant inlet (32) and a connection of the return channels (34) of the first and second area are integrated in the base plate (18). Vehicle battery (10) with at least two battery modules (13, 14) and with a cooling device (16) according to one of the preceding claims. Vehicle battery (10) Claim 8 , wherein the channel element (22) of the return channel of the second area is in contact with a battery housing base (36) when the coolant flows through the return channel and is designed to transfer heat, the battery housing bottom (36) being designed to convey the coolant in the To cool the return duct. Motor vehicle (12) with a vehicle battery (10) according to one of the Claims 8 or 9 .

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