FR3059475A1 - THERMAL EXCHANGE DEVICE FOR A LOWER CHASSIS OF A BATTERY HOUSING - Google Patents

Abstract

A heat exchange device (DE) equips a battery (BA) comprising a housing (BT) comprising a lower frame (CH) having a general shape defined by at least two plane zones (ZP1, ZP3), on each of which is placed at least one electric energy storage module (MC1, MC3), and transition zones (ZC2) providing the transition between these planar zones (ZP1, ZP3). This device (DE) comprises at least one heat exchanger (ET1) comprising upper (P11) and lower (P21) heat exchange plates conforming to the general shape of at least a portion of this lower chassis (CH) at the planar areas and shaped so as to define together an internal circuit having at least a first inlet supplied with heat transfer fluid and a first outlet discharging the heat transfer fluid after it has circulated by exchanging calories with the modules (MC1, MC3) under the flat areas (ZP1, ZP3).

Description

Holder (s): PEUGEOT CITROEN AUTOMOBILES SA Société anonyme.

Extension request (s)

Agent (s): PEUGEOT CITROEN AUTOMOBILES SA Public limited company.

HEAT EXCHANGE DEVICE FOR A LOWER CHASSIS OF A BATTERY BOX.

FR 3 059 475 - A1 (£ /) A heat exchange device (DE) equips a battery (BA) comprising a housing (BT) comprising a lower chassis (CH) having a general shape defined by at least two flat zones ( ZP1, ZP3), on each of which is placed at least one module (MC1, MC3) for storing electrical energy, and by transition zones (ZC2), ensuring the transition between these plane zones (ZP1, ZP3). This device (DE) comprises at least one heat exchanger (ET1) comprising upper (P11) and lower (P21) heat exchange plates conforming to the general shape of at least part of this lower chassis (CH) at the level of the flat and shaped areas so as to define together an internal circuit comprising at least a first inlet supplied with heat transfer fluid and a first outlet evacuating the heat transfer fluid after it has circulated by exchanging calories with the modules (MC1, MC3) under the flat areas (ZP1, ZP3).

HEAT EXCHANGE DEVICE FOR A LOWER CHASSIS

A BATTERY BOX

The invention relates to batteries which include modules for storing electrical energy.

In certain technical fields, such as for example that of vehicles, possibly of the automobile type, batteries are used comprising a housing containing modules for storing electrical energy. These modules can, for example, each comprise at least one electrochemical cell for storing electrical energy, for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd or even lead type.

These modules need to be checked almost permanently so that their lifespan can be optimized. This control usually relates not only to the voltages at the terminals of these modules, but also to the temperatures of these modules. The invention relates more precisely to the control of temperatures with a view to keeping them within a predefined range.

In order to allow such control, the modules are installed at

0 inside a housing which is thermally regulated by heat exchange. When trying to limit the size, the heat exchange is carried out by conduction, by means of exchange plate (s) each comprising an exchange circuit in which a heat transfer fluid from another circuit circulates on the outside of the housing. It will be understood that this heat transfer fluid is used either to capture the calories produced by the modules when they have to be cooled, or to transfer calories to the modules when they have to be heated.

The current heat exchange plates are either placed under the modules, as described in patent document EP 2016/0087319, or

0 inserted between neighboring modules, as described in patent documents EP 1990849, US 2015/0303537 and EP 2337143, or still installed in the modules (for example between some of their cells). In all cases, each heat exchange plate is housed inside the housing, and not outside of the latter, and more precisely against the lower chassis of the housing on which the modules are placed. This is mainly due to the three-dimensional shape of the lower chassis of the housing in current vehicles. Indeed, this lower chassis of the housing has a general shape which is defined by flat zones, placed at possibly different levels and on each of which is placed at least one module, and by transition zones, ensuring the transition (or the passage) between these flat zones, which makes it particularly difficult and complex to install heat exchange plates under this lower chassis and the fluid interconnections between them. These difficulty and complexity of installation are further increased when the height available under the lower chassis of the housing is very reduced (due to the ground clearance) and in particular is not sufficient to allow the use of conduits (or pipes ) interconnection between heat exchange plates or quick couplings (with an associated minimum clearance space) for the coupling of these interconnection conduits.

As for the use of heat exchange plates inside the housing, this poses several problems. Indeed, there is a risk of leakage of

0 heat transfer fluid inside the housing, and therefore a risk of short circuit or fire due to the presence of electrical components. Then, the installation in the battery (or even in the modules) of the heat exchange plates, of the interconnection conduits between the latter and of the fixing means considerably complicates the internal architecture and notably increases the size and the duration of mounting. In addition, there is a wide variety of lower chassis chassis due in particular to the diversity of vehicle body structures, which makes it difficult to design standardized heat exchange devices comprising already interconnected heat exchange plates. between them via conduits. In

In addition, the crossing of the housing by some of the interconnection conduits complicates the positioning of the hollow bodies which are intended to absorb the forces in the event of an impact.

The invention therefore aims in particular to improve the situation.

It proposes in particular for this purpose a heat exchange device intended to equip a battery which comprises a housing comprising a lower chassis having a general shape defined by at least two flat zones, on each of which is placed at least one storage module for electrical energy, and by transition zones, ensuring the transition between these planar zones.

This heat exchange device is characterized in that it comprises at least one heat exchanger comprising upper and lower heat exchange plates conforming to the general shape of at least part of the lower chassis of the battery case at the level at least one of the flat zones and shaped so as to define together an internal circuit comprising at least a first inlet capable of being supplied with heat transfer fluid and a first outlet capable of discharging the heat transfer fluid after it has circulated in exchanging calories with the modules under the flat areas.

Each heat exchanger conforming to the general shape of at least part of the lower chassis of the housing, the heat exchange is optimized at the level of the flat areas located under the modules and the use of quick couplings in areas where the available height is avoided is small. In addition, since the heat exchange device is now placed under the lower chassis of the housing, there is no longer any risk of heat transfer fluid leaking inside the housing.

The heat exchange device according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

- In a first embodiment, the first inlet and first outlet of (each) heat exchanger can be adapted to be coupled to an external circuit in which the heat transfer fluid circulates;

> the (each) first input and the (each) first output can be respectively connected to two connection conduits which are suitable for being coupled to the external circuit;

- In a second embodiment, it can comprise at least two heat exchangers, one, said upstream, comprising an internal circuit comprising a first inlet capable of being supplied with heat transfer fluid from an external circuit, a first clean outlet supplying coolant to the external circuit, a second output connected to a first coupling conduit, and a second input connected to a second coupling conduit, and the other, said downstream, comprising another internal circuit comprising a first connected input to the first coupling conduit and a first outlet connected to the second coupling conduit;

> the first input and first output of the upstream heat exchanger îo can be respectively connected to two connection conduits suitable for being coupled to the external circuit;

- each upper heat exchange plate and each lower heat exchange plate can be shaped by stamping or by molding;

i5 - each upper heat exchange plate can be made of aluminum.

The invention also provides a battery comprising, on the one hand, a housing comprising a lower chassis having a general shape defined by at least two flat zones, on each of which is placed at least

0 an electrical energy storage module, and by transition zones, ensuring the transition between these flat zones, and, on the other hand, a heat exchange device of the type of that presented above and fixedly attached to a lower face of the lower chassis of the housing.

For example, each module can comprise at least one electrochemical cell.

Also, for example, its heat exchange device can be fixedly attached to the underside of the lower chassis of its housing with the interposition of at least one transfer layer suitable for transferring calories.

0 The invention also provides a vehicle, optionally of the automobile type, and comprising an external circuit in which a heat transfer fluid and at least one battery of the type presented above circulates and the heat exchange device of which is coupled to this external circuit.

Other characteristics and advantages of the invention will appear on examining the detailed description below, and the attached drawings (obtained in CAD / CAD ("Computer Aided Design / Computer Aided Drawing"), whence the apparently discontinuous nature of certain lines), on which:

- Figure 1 schematically illustrates, in a bottom view, part of an example of a vehicle body structure to which a battery is secured and an exemplary embodiment of a heat exchange device according to the invention, îo - Figure 2 schematically illustrates, in a bottom view, the upper heat exchange plates of the two heat exchangers of the heat exchange device of FIG. 1,

FIG. 3 diagrammatically illustrates, in a view from below, the lower heat exchange plates of the two heat exchangers of the heat exchange device of FIG. 1, and

FIG. 4 schematically illustrates, in a longitudinal section view, part of the body structure of FIG. 1.

The purpose of the invention is in particular to propose a DE heat exchange device intended to equip a BA battery with MCj storage modules.

0 of electrical energy, which is itself intended to equip a vehicle.

In what follows, it is considered by way of nonlimiting example, that the battery BA is intended to equip a vehicle of the automobile type, such as for example a car. However, the invention is not limited to this type of vehicle. It relates in fact to any vehicle comprising at least one battery with electrical energy storage modules, and in particular land, sea (or river), and air vehicles.

Furthermore, it is considered in what follows, by way of nonlimiting example, that the vehicle comprises a powertrain (or GMP) of the all-electric type, that is to say comprising an electric drive machine.

0 coupled to BA battery. But the GMP could be of the hybrid type, that is to say comprising a heat engine and an electric motor coupled to the BA battery.

Finally, it is considered in what follows, by way of nonlimiting example, that each module MCj comprises at least one electrochemical cell. However, the invention is not limited to this type of electrical energy storage module. It relates to any type of electrical energy storage module before being subject to thermal regulation.

For example, the electrochemical cells of the BA battery are of the lithium-ion (or Li-ion) type. But these cells could also be of the Ni-Mh or Ni-Cd type or even lead, for example.

There is diagrammatically illustrated in FIG. 1, part of an example of a body structure SC of a vehicle (here motor vehicle) to which a battery BA (very partially visible) is secured and an example embodiment of a device DE heat exchange according to the invention.

As appears better in FIG. 4, the battery BA comprises a box BT comprising in particular a lower chassis CH having a general shape i5 defined by at least two flat zones ZPj, which are placed at possibly different levels (relative to the direction vertical) and on each of which is placed at least one module MCj (here comprising at least one electrochemical cell), and by transition zones ZCk, which ensure the transition between these plane zones ZPj.

0 Here, the term “transition zone” means a zone ensuring the transition (or passage) from a plane zone ZPj situated at a first level to another plane zone ZPj 'situated at a second level, possibly different from the first level . It can therefore make it possible to pass from one level to another or else to pass from a plane zone ZPj to another plane zone ZPj ’. Such a transition zone ZCk can, for example result from a local conformation of the lower chassis CH (for example resulting from a stamping) or from the presence of a hollow body or a tunnel or at least part of equipment in or under the lower chassis CH, such as for example an electrical harness or a member prepared on the battery BA.

0 Note that at least one of the planar zones ZPj can support several (at least two) modules MCj (possibly of different shapes and / or orientations).

Also as illustrated in FIG. 4, the box BT comprises an upper wall PS which defines, for example, a cover and which is fixed (in a sealed manner) to the lower chassis CH, the latter (CH) being fixed to a lower face of the SC body structure.

A heat exchange device DE, according to the invention, comprises at least one heat exchanger ET] comprising an upper heat exchange plate P1 j and a lower heat exchange plate P2j which conform to the general shape of at least part of the lower chassis CH of the housing BT at at least one of the flat zones ZPj. The term "marrying" is understood here to mean following this general shape as closely as possible, and therefore to have a shape substantially homologous to this general shape of at least part of the lower chassis CH at at least 1 'one of its flat zones ZPj. The upper heat exchange plates P1 j and lower P2j of each heat exchanger ETj are therefore shaped in order to conform to this general shape.

In addition, and as appears better in FIGS. 2 to 4, these upper heat exchange plates P1j and lower P2j are shaped so as to define together an internal circuit Cl which comprises at least one first input E1j suitable for being supplied with heat transfer fluid and a first outlet S1 j suitable for discharging this heat transfer fluid

0 after it has circulated by exchanging calories with the MCj modules under the flat zones ZPj of the lower chassis CH of the BT box.

The heat transfer fluid which feeds the first input E1j of a heat exchanger ETj can come from another exchanger ETj ’(with j’ + j), or from an external circuit. In the case of a vehicle, this external circuit can, for example, be a part of the thermal regulation circuit (heating / cooling) of a heat engine or of a cooling facade.

The heat transfer fluid is, for example, a liquid. Thus, it can be water, possibly mixed with an additive, or an oil or liquid sodium.

0 In the example illustrated without limitation in Figures 1 to 4, the DE heat exchange device comprises two heat exchangers

ETj, one (ET1 (j = 1)), says upstream, and the other (ET2 (j = 2)), says downstream. The concepts of "upstream" and "downstream" are used here with reference to the direction of circulation of the heat transfer fluid. In other words, an upstream heat exchanger (here

ET1) supplies heat transfer fluid to a downstream heat exchanger (here ET2).

The upstream heat exchanger ET1 comprises an internal circuit C1 comprising a first input E11 suitable for being supplied with heat transfer fluid from an external circuit, a first output S11 suitable for supplying heat transfer fluid to the external circuit, a second output S21 connected to a first coupling conduit (or pipe) C21, and a second input E21 connected to a second coupling conduit (or pipe) C22.

The downstream heat exchanger ET2 comprises another internal circuit Cl îo comprising a first input E12 connected to the first coupling conduit (or pipe) C21 and a first output S12 connected to the second coupling conduit (or pipe) C22.

In the example illustrated without limitation in FIGS. 1 to 4, the heat exchange device DE only comprises two heat exchangers ETj. Consequently, the first input E11 and first output S11 of the upstream heat exchanger ET1 are respectively connected to two connection conduits (or pipes) C11 and C12 which are suitable for being coupled to the external circuit. This last coupling can, for example, be done via quick couplings which are placed in an area under the structure

0 of SC body where the height available with respect to the ground clearance is sufficient to accommodate them with an associated minimum clearance.

But in an alternative embodiment in which the heat exchange device DE comprises more than two heat exchangers ETj, there is at least one intermediate heat exchanger between the upstream heat exchanger ET1 and the downstream heat exchanger ET2. In this case, the intermediate heat exchanger ETj 'comprises first inputs E1j' and first output S1j 'which are respectively connected to two coupling conduits (or pipes) which are suitable for being coupled respectively to the second output and second input of E21 from the previous heat exchanger

0 (for example the upstream heat exchanger ET1), and second input and output connected to the internal circuit C1 of the next heat exchanger via respectively two coupling conduits (or pipes).

In FIG. 3 are shown the entire example of an internal circuit Cl of the upstream heat exchanger ET1 and the start of the internal circuit Cl of the downstream heat exchanger ET2.

Each internal circuit Cl can be defined by means of concave or convex zones ZC defining at least passages or channels for the circulation of the heat transfer fluid and of ribs (or partitions) N intended to channel or orient the heat transfer fluid within passages or channels. These concave or convex zones ZC and these ribs N are defined in the upper heat exchange plates P1 j and lower P2j of each heat exchanger ETj. It will be understood that a rib N ïo defined in one of the upper heat exchange plates P1j and lower P2j is intended to closely contact the other heat exchange plate, possibly within a concave or convex zone ZC, in order to ensure good plating with the facing wall and to force the circulation of the liquid. Furthermore, a passage or channel can be defined by a single i5 concave or convex zone ZC defined in one of the upper heat exchange plates P1 j and lower P2j, or else by a concave zone ZC defined in the plate lower heat exchange P2j and by a convex zone ZC defined in the upper heat exchange plate P1 j. It is best to keep the maximum level surface on top in order to have

0 maximum surface area in heat exchange with the module. Note that a rib N can possibly be defined inside a concave or convex zone ZC.

In the example illustrated without limitation in FIGS. 1 to 4:

- the upper heat exchange plate P11 of the upstream heat exchanger ET 1 only includes convex zones ZC,

- The lower heat exchange plate P21 of the upstream heat exchanger ET1 includes both concave zones ZC, intended to define passages or channels with corresponding convex zones ZC of the upper heat exchange plate P11, and ribs N,

0 - the upper heat exchange plate P12 of the downstream heat exchanger ET2 only comprises convex zones ZC, and

the lower heat exchange plate P22 of the downstream heat exchanger ET2 comprises both concave zones ZC, intended to define ίο passages or channels with corresponding convex zones ZC of the upper heat exchange plate P12, and ribs N.

Furthermore, in the example illustrated without limitation in FIGS. 1 to 4, the upstream heat exchanger ET1 is subdivided into two sub-parts

SP1 and SP2 extending mutually via a shaped portion, placed at two different levels (in the vertical direction) and associated with two different planar zones ZP1 and ZP3 and supporting modules MC1 and MC3 respectively. On the other hand, the downstream heat exchanger ET2 is not subdivided into sub-parts, but it could be. Note that an ETj heat exchanger can be subdivided into more than two sub-parts, for example three or four.

It will also be noted that in the example illustrated without limitation in FIGS. 1 and 4, the second sub-part SP2 of the upstream heat exchanger ET1 is used not only to thermally regulate each module MC3 i5 located in the flat zone ZP3 located just at -above it, but also to thermally regulate a PR charging plate located just below it and intended to ensure the recharging of the battery BA by induction. This PR charging plate is more precisely fixedly fixed to a support SUP which is itself fixedly fixed to the body structure SC

0 and / or to the lower chassis CH of the LV box.

In the illustrative figures, the heat exchange device DE comprises two heat exchangers ETj fluidly coupled to one another by two coupling conduits (or pipes) C21 and C22. However, the DE heat exchange device could comprise only one heat exchanger or at least two heat exchangers independent of each other. In this case, the first input E1j and first output S1j of each heat exchanger ETj are suitable for being coupled to an external circuit in which the heat transfer fluid circulates. For example, the first input E1j and first output S1j of each exchanger

0 thermal ETj can then be respectively connected to two conduits (or pipes) of connection C11 and C12 which are suitable for being coupled to the external circuit. This last coupling can, for example, be done via quick couplings which are placed in an area located under the body structure SC where the height available relative to the ground clearance is sufficient to accommodate them with an associated minimum clearance.

It will be noted that each upper heat exchange plate P1 j and each lower heat exchange plate P2j of each heat exchanger ET] can, for example, be shaped by stamping or by molding.

It will also be noted that to optimize the exchange of calories by conduction it is advantageous that each upper heat exchange plate P1 j has a high thermal conductivity and if possible that each lower heat exchange plate P2j is made of a material which is less or not thermally conductive to avoid losing calories to the outside (except when there is a PR charging plate located below it (as explained below). The material in which each lower heat exchange plate P2j must i5, however, allow welding with the associated upper heat exchange plate P1j Alternatively, a lower heat exchange plate P2j can be made of the same material as the upper heat exchange plate P1 j associated and be coated with a plastic material which is not very conductive (for example one can have a conductive material r

0 thermally with an air barrier placed below and providing thermal insulation).

For example, each upper heat exchange plate P1 j of each heat exchanger ETj can be made of aluminum (material which has the advantage of being light compared to copper, the thermal conductivity of which is certainly slightly higher than its own but which is heavier).

It will also be noted that the heat exchange device DE can be fixedly attached to the underside of the lower chassis CH of the housing BT with the interposition of at least one transfer layer (or "thermal pad")

0 which is suitable for ensuring a transfer of calories between each heat exchanger ETj and each module MCj supported by the flat area ZPj located above it (ETj) as well as a possible recharging plate PR located below it ( ETj).

It will also be noted that it is also possible to place a transfer layer between the modules MCj and the lower chassis CH of the housing BT.

It will also be noted that it is also possible to place under the heat exchange device DE, preferably by leaving a small space (for example between 4 mm and 6 mm), a screen intended to protect it while ensuring an aeraulic function. and an isolation function to limit the exchange of calories with the road.

The invention offers several advantages, including:

- a compactness leaving a maximum of space for the modules, and îo avoiding having to reassemble the positions of the seat seats,

- compatibility with the forces undergone in the event of an impact (front, side, rear) and with the mechanical strength of the battery, since it does not require any modification to the number and positions of the hollow bodies of the charged battery to absorb efforts, i5 - a significant reduction in battery manufacturing time,

- a significant reduction in the number of parts to be assembled and installed,

- the assurance that the heat transfer fluid will not leak inside the battery,

- the possibility of also ensuring the cooling of an induction charging plate,

0 - disassembly of the heat exchangers independent of the removal of the battery, which saves time in the event of intervention in an after-sales service,

- an assembly with the battery either before the manufacture of the vehicle, or during the manufacture of the vehicle, or as part of an intervention in an after-sales service (aftermarket)

- modularity of the battery since it can be installed with or without a heat exchange device, as required.

Claims (10)

1. Heat exchange device (DE) for a battery (BA) 5 comprising a housing (BT) comprising a lower chassis (CH) having a general shape defined by at least two flat zones (ZPj), on each of which is placed at least one module (MCj) for storing electrical energy, and by transition zones (ZCk), ensuring the transition between said flat zones (ZPj), characterized in that it comprises at least one heat exchanger (ET]) comprising upper (P1 j) and lower heat exchange plates (P2j) matching said general shape of at least part of said lower chassis (CH) at at least one of said flat zones (ZPj) and shaped so as to define together an internal circuit (Cl) comprising at least a first entry (E1 j) suitable for being 15 supplied with heat transfer fluid and a first outlet (S1 j) suitable for discharging said heat transfer fluid after it has circulated by exchanging calories with said modules (MCj) under said flat areas (ZPj). 2. Device according to claim 1, characterized in that said first input (E1 j) and first output (S1 j) are adapted to be coupled to 2 0 an external circuit in which circulates said heat transfer fluid. 3. Device according to claim 2, characterized in that said first input (E1 j) and first output (S1 j) are respectively connected to two connection conduits (C11, C12) suitable for being coupled to said external circuit. 25 4. Device according to claim 1, characterized in that it comprises at least two heat exchangers (ETj), i) one (ET1), said upstream, comprising an internal circuit (Cl) comprising a first input (E11) adapted to be supplied with heat transfer fluid from an external circuit, a first outlet (S11) suitable for supplying heat transfer fluid to said circuit External, a second output (S21) connected to a first coupling conduit (C21), and a second input (E21) connected to a second coupling conduit (C22), and ii) the other (ET2), said downstream, comprising another internal circuit (Cl) comprising a first input (E12) connected to said first coupling conduit (C21) and a first output (S12) connected to said second coupling conduit (C22). 5. Device according to claim 4, characterized in that said first inlet (E11) and first outlet (S11) of said heat exchanger 5 upstream (ET1) are respectively connected to two connection conduits (C11, C12) suitable for being coupled to said external circuit. 6. Device according to one of claims 1 to 5, characterized in that each upper heat exchange plate (P1j) and each lower heat exchange plate (P2j) are shaped by stamping or by molding. 7. Device according to one of claims 1 to 6, characterized in that each upper heat exchange plate (P1j) is made of aluminum. 8. Battery (BA) comprising a housing (BT) comprising a lower chassis (CH) having a general shape defined by at least two flat zones (ZPj), on each of which is placed at least one storage module (MCj) d electrical energy, and by transition zones (ZCk), ensuring the transition between said planar zones (ZPj), characterized in that it further comprises a heat exchange device (DE) according to one of 2 0 previous claims, fixedly secured to a lower face of said lower chassis (CH) of the housing (BT). 9. Battery according to claim 8, characterized in that each module (MCj) comprises at least one electrochemical cell. 10. Vehicle comprising an external circuit in which a heat transfer fluid circulates, characterized in that it further comprises at least one battery (BA) according to one of claims 8 and 9, including the heat exchange device (DE ) is coupled to said external circuit. 1/2