COMPARTMENT FOR EQUIPMENT LIKELY TO EMIT HEAT

Abstract

The invention relates to a compartment for equipment likely to emit heat during its operation, in particular for a device for storing electrical energy for a motor vehicle, said compartment having at least one cooling plate arranged to have a cooling fluid flowing through it and arranged to cool said equipment. The compartment further includes an upper housing arranged to accommodate said electrical equipment, and a lower housing, in which at least one fluid connection element is placed in order to supply the cooling plate with fluid, the lower and upper housing being isolated from each other in a fluidly sealed manner.

Claims

1. A compartment for an item of equipment liable to give off heat during its operation, in particular for an electrical energy storage device for a motor vehicle, the compartment having at least one cooling plate which is designed to be passed through by a cooling fluid and which is designed to cool said item of equipment, the compartment comprising a bottom cover with at least one layer of composite material and a primary additional layer of non-reinforced polymer material.

2. The compartment as claimed in claim 1, wherein the bottom cover includes a secondary additional layer of non-reinforced polymer material, the at least one layer of composite material being arranged between the primary additional layer of non-reinforced polymer material and the secondary additional layer of non-reinforced polymer material.

3. The compartment as claimed in claim 1, wherein the compartment furthermore has an upper housing designed to receive said item of equipment, and a lower housing defined by the bottom cover together with the at least one cooling plate, in which at least one fluid connection element for supplying the cooling fluid to the at least one cooling plate is placed, the lower housing and upper housing being insulated from one another in a fluid-tight manner.

4. The compartment as claimed in claim 3, wherein the at least one cooling plate separates the lower housing from the upper housing.

5. The compartment as claimed in claim 4, wherein the bottom cover includes a cooling fluid channel, and the at least one fluid connection element is connected to the cooling fluid channel.

6. The compartment as claimed in claim 5, wherein a seal is disposed on a joining periphery between the lower housing and the upper housing.

7. The compartment as claimed in claim 6, wherein the upper housing has at least one frame, in particular made of aluminum, which defines a periphery of the upper housing, and the seal is in contact with the at least one frame.

8. The compartment as claimed in claim 7, wherein the seal is disposed in a tight manner between a zone of the at least one frame and a zone of the at least one cooling plate, and between a zone of the at least one frame and a zone of the bottom cover.

9. The compartment as claimed in claim 6, wherein an upper cover is provided to bear against the at least one frame for closing of the compartment, in particular with the interposition of the seal, in particular made of electrically conductive material.

10. An electrical energy storage device having a plurality of battery cells that are in particular disposed in a row, and a compartment for an item of equipment liable to give off heat during its operation, in particular for an electrical energy storage device for a motor vehicle, the compartment having at least one cooling plate which is designed to be passed through by a cooling fluid and which is designed to cool said item of equipment, the compartment comprising a bottom cover with at least one layer of composite material and a primary additional layer of non-reinforced polymer material, said battery cells being placed in the compartment in thermal interaction with the cooling plate.

11. The compartment as claimed in claim 7, wherein the seal is disposed in a tight manner between a zone of the frame and a zone of a cooling plate, or between a zone of the frame and a zone of the bottom cover.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Further features, details and advantages of the invention will become more clearly apparent upon reading the detailed description given below, and from several exemplary embodiments that are given by way of nonlimiting indication, with reference to the attached schematic drawings, in which:

[0057] FIG. 1 is a schematic side view of a compartment according to one example of the invention,

[0058] FIG. 2 shows the compartment of FIG. 1 in cross section,

[0059] FIG. 3 is a schematic view of a compartment according to another example of the invention,

[0060] FIG. 4 is a sectional view of FIG. 3,

[0061] FIG. 5 is another schematic view of FIG. 4, and

[0062] FIG. 6 is a sectional view of the compartment.

DETAILED DESCRIPTION OF THE INVENTION

[0063] FIGS. 1 and 2 show an electrical energy storage module 1 having a plurality of battery cells 9, which are visible in FIG. 2, and a compartment 2.

[0064] The compartment 2 has two cooling fluid channels 3 for circulating a cooling fluid, which are visible in FIG. 1 and are parallel. FIG. 1 shows the lower and outer face of the compartment 2. The compartment 2 defines, together with an upper cover that is not shown, a casing 5 which contains the battery cells 9. The bottom of the casing 5 is on the compartment 2.

[0065] Each cooling fluid channel 3 is obtained by molding of a polymer-based material that can possibly comprise reinforcing fibers, with fluid-assisted injection molding, in particular gas- or liquid-assisted injection molding, for forming the cooling fluid channel 3 in the polymer-based material. Thus, the polymer-based material forms a first layer 8 of polymer material.

[0066] Each cooling fluid channel 3 has an internal wall 10 without a joint, which is the result of the hollowing of the polymer-based material by the fluid injected during the molding.

[0067] Each cooling fluid channel 3 has a cylindrical shape, at least over part of its length, in particular with a rectangular or oval or round cross section.

[0068] The first layer 8 of polymer material in which the cooling fluid channels 3 are formed is connected to a second layer 11 of composite material.

[0069] Composite material is understood to mean a material comprising at least two different materials such as plastic and metal. According to the invention, the preferred composite materials correspond to materials that are both robust and lightweight. Composite materials such as a mixture of a thermoplastic with reinforcing fibers are particularly well suited to such a use. By way of illustration, the composite material can correspond to polypropylene with glass and/or carbon fibers. Specifically, polypropylene corresponds to a lightweight material and the glass and/or carbon fibers reinforce the structure of the casing. Polyamide 6 with glass fibers is also possible. The composite material can also be said to correspond to reinforcing fibers pre-impregnated with a thermoplastic resin.

[0070] This connection is the result of overmolding or co-molding between the first layer 8 of polymer material and the second layer 11 of composite material, which has the cooling fluid channels 3 for circulating cooling fluid.

[0071] The second layer 11 of composite material has openings 13 and the first layer 8 of polymer material, which forms the cooling fluid channels 3, passes through these openings 13 such that each cooling fluid channel 3 also passes through the opening 13 associated with the second layer 11 of composite material.

[0072] The first layer 8 of polymer material in which the cooling fluid channel 3 is formed is in the form of a layer which extends over a face of the second layer 11 of composite material.

[0073] The second layer 11 of composite material is planar over at least part of its surface area in a planar region 17.

[0074] The first layer 8 of polymer material and the second layer 11 of composite material have an edge 15 that is inclined with respect to the planar region 17, and the cooling fluid channel 3 passes into the first layer 8 of polymer material at the edge 15.

[0075] Each cooling fluid channel 3 in the material is connected to a fluidic connection member 27 at the inclined edge 15.

[0076] Each fluidic connection member 27 is overmolded with the material of the first layer 8 of polymer material.

[0077] The compartment 2 has a cooling plate 20 disposed on a side 21 of the layer 11 of composite material that is opposite to the side 22 of the first layer 8 of polymer material.

[0078] The cooling plate 20 is designed to be passed through by a cooling fluid also circulating in the cooling fluid channels 3 of the first layer 8 of polymer material. These cooling fluid channels 3 are feeder channels which respectively supply and evacuate the cooling liquid circulating in the cooling plate 20. Provision is for example made for a single supply feeder channel and a single evacuation feeder channel.

[0079] The cooling plate 20 is formed of two sub-plates 24 which, once assembled, form a cooling fluid circulation circuit 39.

[0080] The first layer 8 of polymer material has connection portions 29 which are formed in one piece with the rest of the layer and which are designed to be connected to the cooling plate 20. The connection portion 29 protrudes through the layer 11 of composite material and is passed through by the associated cooling fluid channel 3 in order to lead the cooling fluid channel 3 up to the cooling plate 20. The cooling plate 20 faces the second layer 11 of composite material.

[0081] The first layer 8 of polymer material has grooves 33 for forming the cooling fluid channels 3 and reinforcing ribs 34, in particular of honeycomb shape, for mechanically reinforcing the compartment 2.

[0082] The fluid for the assisted injection molding can be water.

[0083] The first layer 8 of polymer material thus occupies only part of the outer face of the second layer 11 of composite material, and not all of this face. The first layer 8 of polymer material occupies for example less than 50% of the outer face of the second layer 11 of composite material, or even less than 25% thereof.

[0084] The cells 9 are placed in the compartment 2 in thermal interaction with the cooling plate 20.

[0085] Each cooling fluid channel 3 has a length of at least 5 cm, in particular of at least 10 cm.

[0086] The composite material of the second layer 11 of composite material comprises glass fibers, and possibly, in a variant, carbon fibers or fibers of another nature, which are pre-impregnated with a thermoplastic resin.

[0087] The compartment 2 has a raised edge 36 on its periphery.

[0088] The honeycomb structure 34 is toward the outside of the casing 5.

[0089] The cooling liquid used in this case can in particular be a liquid refrigerant based on carbon dioxide, such as R744 for example, 2,3,3,3-tetrafluoropropene (or HFO-1234yf) or 1,1,1,2-tetrafluoroethane (or R-134a). The cooling liquid can also be a nanofluid. The cooling liquid can also be water, possibly including additives.

[0090] The battery cells comprise, for example, a plurality of lithium-ion (Li-ion) batteries for use in a hybrid vehicle. In another embodiment, the plurality of battery cells are Li-ion batteries for use in a battery-powered electric vehicle.

[0091] The cooling plate 20 forms a heat exchanger comprised in a cooling circuit, not shown, of the type comprising a compressor and further heat exchangers.

[0092] The cooling plates 20 are, for example, an assembly of two aluminum walls delimiting ducts for circulating cooling fluid, taking the form of a meandering path, for example.

[0093] The compartment 2 and the battery cells 9 form, together with other components, an electrical energy storage device 40 for a motor vehicle.

[0094] The first layer 8 of polymer material and the second layer 11 of composite material form a bottom cover 88.

[0095] FIGS. 3 to 5 show a compartment 80 for battery cells 9 of a motor vehicle according to another embodiment. The compartment 80 has cooling plates 20 which are designed to be passed through by a cooling fluid and which are designed to cool the battery cells 9.

[0096] The compartment 80 furthermore has an upper housing 81 designed to receive the battery cells 9, and a lower housing 82 in which fluid connection elements 83 for supplying fluid to the cooling plates 20 are placed.

[0097] The lower housing 82 and the upper housing 81 are insulated from one another in a fluid-tight manner.

[0098] The cooling plates 20 separate the lower housing 82 from the upper housing 81, as can be better seen in FIGS. 4 and 5.

[0099] A plurality of cooling plates 20 separates the lower housing 82 from the upper housing 81, and these cooling plates 20 are disposed in parallel rows.

[0100] Each cooling plate 20 has a fluid inlet 84 and a cooling fluid outlet 85 which are each connected to one of the fluid connection elements 83, and these fluid inlets 84 and outlets 85 are all directed toward the lower housing 82.

[0101] Thus, in the event of a leak at these inlets 84 and outlets 85, the cooling fluid flows into the lower housing 82, and not into the upper housing 81, so as to preserve the battery cells 9.

[0102] Ducts are provided within the cooling plates 20 in order to circulate cooling fluid.

[0103] The compartment 80 has a bottom cover 88 comprising cooling fluid channels 3 like those described in the previous example.

[0104] The fluid connection elements 83 are connected to these cooling fluid channels 3, and are for example formed by a material extension that also forms the cooling fluid channels 3. These cooling fluid channels 3 are produced by fluid-assisted injection molding in the first layer 8 of polymer material, as described in the previous example.

[0105] The bottom cover 88 has a substantially planar main face 89.

[0106] The bottom cover 88 together with the cooling plates 20 defines the lower housing 82.

[0107] The lower housing 82 and the upper housing 81 cover substantially the same surface area. These housings 81 and 82 are thus in a vertically stacked arrangement when the assembly is mounted on the vehicle.

[0108] The bottom cover 88 has a layer of composite material based on polymer and more particularly plastic and thermoplastic.

[0109] The lower housing 82 has, in free space, a height h of less than 25%, in particular of less than 15%, of the height H of the upper housing 82.

[0110] Seals 90 are disposed on a joining periphery 91 between the lower housing 82 and the upper housing 81.

[0111] The upper housing 81 has an aluminum frame 93, which defines a periphery 95 of the upper housing, and the seal 90 is in contact with the frame 93.

[0112] The frame 93 has external bars 94 forming the periphery 95 and partitions 96, which form a grid, for forming receptacles 97 that are each intended to receive one battery cell 9. These partitions 96 form, for example, two identical rows of multiple receptacles 97.

[0113] The external bars 94 in particular have a cellular structure. The external bars 94 are for example made of steel or aluminum.

[0114] The cooling plates 20 are for example assembled on the frame 93 by screwing or adhesive bonding.

[0115] The seals 90 are provided between the external bars 94 and partitions 96 of the frame 93 on the one hand and the lower housing 82 on the other hand.

[0116] The seals 90, for example based on silicone, are disposed in a tight manner between a zone of the frame 93 and a zone of a cooling plate 20, and/or between a zone of the frame 93 and a zone of the bottom cover 88.

[0117] Each seal 90 is made of electrically conductive material so as to contribute to an electromagnetic protection function for the upper housing 81 which receives the battery cells 9.

[0118] An upper cover 98 is designed to bear against the frame 93 for closing of the compartment, with the interposition of seals 90.

[0119] The upper cover 98 comprises a composite material based on polymer material, and in particular has a substantially flat shape.

[0120] The feeder cooling fluid channels 3 are in particular directed toward the lower housing 82.

[0121] Regardless of the embodiment described above, the invention relates to the sealing of the compartment 2, 80 and in particular to the sealing of the bottom cover 88. As illustrated in FIG. 6, the bottom cover 88 corresponds to a multi-layer structure comprising at least one layer 100 of composite material and an additional layer 102 of non-reinforced polymer material. The additional layer 102 of non-reinforced polymer material corresponds, for example, to plastic or other thermoplastic without any reinforcing fibers. The additional layer 102 of non-reinforced polymer material is preferably impermeable to the cooling fluid in order to guarantee the sealing of the bottom cover 88. In other words, the additional layer 102 of non-reinforced polymer material is made of, or manufactured from, a material that is impermeable to a liquid refrigerant such as R744, HFO-1234yf, R-134a or water.

[0122] Non-reinforced polymer material is understood to mean a preferably thermoplastic material having no reinforcing fibers. In order to facilitate the affinity between the layers, it is preferable for the polymer, in other words the thermoplastic, of the additional layer 102 of non-reinforced polymer material to be the same as that of the layer 100 of composite material. Of course, affinity is possible between different polymers, for example chemically compatible polymers, or else polymers connected by forming a complex or by prior treatment of the first and second layers, or both of the above.

[0123] The bottom cover 88 can furthermore comprise other layers. As illustrated in FIG. 6, the bottom cover 88 can comprise a layer corresponding to a fire barrier 104.

[0124] According to one of the aspects of the invention, the fire barrier 104 is formed by one of the following elements: [0125] a fireproof film, in particular made of plastic, in particular thermoplastic, with suitable adjuvants, [0126] a layer comprising aramid, for example a woven fabric layer, [0127] a metal layer or foil.

[0128] According to one of the aspects of the invention, the fire barrier 104 is a layer that is incorporated in the multi-layer structure of the bottom cover 88.

[0129] The fire barrier 104 is formed at the same time as the other layers 100, 102 of the multi-layer structure, for example.

[0130] As illustrated in FIG. 6, the bottom cover 88 can comprise a plurality of layers. For example, the bottom cover 88 can comprise two layers 100 of composite material and two additional layers 102 of non-reinforced polymer material, possibly with a fire barrier 104 arranged centrally between these four layers.

[0131] According to other embodiments that are not illustrated, the bottom cover 88 can comprise a layer 100 of composite material and two additional layers 102 of non-reinforced polymer material on either side of this layer 100 of composite material, possibly with a fire barrier layer 104.

[0132] However, according to the invention, in order to ensure improved sealing and to prevent any leakage of cooling fluid, it is preferable for the outer layer of the bottom cover 88, that is to say the layer directed toward the bottom of the vehicle, or the layer directed in the direction opposite to the battery cells 9, to be the additional layer 102 of non-reinforced polymer material. In the case where there are two additional layers 102 of non-reinforced polymer material, it is also possible for the outer layer and the inner layer, that is to say the layer directed toward the battery cells 9, to both be additional layers 102 of impermeable non-reinforced polymer material.

[0133] According to one of the aspects of the invention that is not illustrated, a second fire barrier 104 is provided in the form of an inner layer of the compartment 2, 80, in particular a layer directed toward the battery cells 9 to be housed in said compartment 2, 80. Thus, two fire barriers 104 can be provided on the two faces, inner and outer faces, of the compartment 2, 80 so as to reinforce the fire protection of the compartment 2, 80.

[0134] The fire barrier 104 extends over the entire bottom cover 88, in particular over the outside thereof.

[0135] According to the first embodiment, the second layer 11 of composite material corresponds to the first layer 100 of composite material, and the first layer 8 of polymer material corresponds to the additional layer 102 of non-reinforced polymer material.

[0136] One aspect according to the invention provides that the upper cover 98 has the same multi-layer structure as the bottom cover 88.