Thermal conditioning device and charging device comprising thermal conditioning device

Abstract

The invention relates to a thermal conditioning device (1), in particular a cooling device, for an electrical component (2) susceptible to release heat during operation, in particular for an electrical energy storage module, comprising a first plate (2) and a second plate (3) assembled with the first plate, each plate being delimited by an edge, the invention relates to a device (1) for producing a heat transfer fluid, in particular a refrigerant fluid, comprising a plurality of plates (2), in order to together form a plurality of flow-through channels (5) for a heat transfer fluid, in particular a refrigerant fluid, which define channel regions (6), at least one of said plates being stamped in order to form part of the walls of the channels, the assembly of the two plates being effected by laser welding (7) at the walls of the channels, said device being characterized in that the two plates are welded together by means of laser welding (7). A region at least partially defining a perimeter of the channel region includes a different assembly means feature (8) than laser transmission welding (7) selected from the group consisting of laser welding with filler wire, adhesive bonding, friction stir welding, or a combination thereof.

Description

Technical Field

[0001] The invention relates to a heat regulating device, in particular a cooling device, in particular for electrical components which tend to release heat during operation, in particular a device for cooling at least one battery or battery cell of a vehicle, such as a motor vehicle.

[0002] The vehicle may be a land vehicle, a sea vehicle or an air vehicle.

[0003] The components to which the present invention relates may be electrical energy storage elements, in particular battery elements, or power electronic elements, such as, but not limited to, semiconductors, such as diodes or transistors. They may also be components of computer servers. Background Art

[0004] Electrical or electronic systems, such as electrical energy storage devices in motor vehicles or computer servers, can be subject to significant constraints due to the need to supply components that require large amounts of energy or because they need to perform considerable information processing in a very short period of time. Consequently, when these electrical or electronic systems are used intensively, they tend to release large amounts of heat and thus reach high temperatures, which reduces the service life of the electrical or electronic systems.

[0005] To limit the temperature of electrical or electronic systems, it is known practice to provide cooling devices associated with these systems. Such cooling devices are arranged near heat-releasing components of the electrical or electronic system and flow through them a cooling fluid whose temperature allows it to exchange heat with these components and cool them. These cooling devices can, in particular, be plate devices formed by assembling at least two pressed plates that are welded together to form channels between the plates, which allow the cooling fluid to circulate.

[0006] The invention relates in particular to a plate heat exchanger intended for circulation of a refrigerant fluid for cooling batteries of electric or hybrid vehicles.

[0007] In industry, these exchangers are usually made of metal and assembled by brazing.

[0008] Despite being currently very common in the industry, the brazing method has drawbacks, in particular the carbon footprint of this manufacturing method, and therefore alternative solutions for joining the two plates are gradually being proposed, with the aim in particular of reducing the electricity consumption and therefore the emissions indirectly generated by this method, one such solution being the assembly of the two plates by welding, in particular by laser welding.

[0009] Laser welding offers several advantages. Specifically, it consumes less energy and produces less pollution than brazing. This allows for reliable, leak-free joints, particularly along straight lines. However, heat exchangers include other types of paths, such as bends, loops, and other complex paths.

[0010] These paths where the direction of the laser beam changes are more sensitive to weld defects such as cracks, which can lead to leaks.

[0011] Therefore, there is a need to obtain a heat exchanger that is robust and leak-free, and to do so with the aid of a more environmentally friendly, fast and reliable method. Summary of the Invention

[0012] The object of the present invention is to at least partially overcome one or more of the above-mentioned disadvantages by providing a heat exchanger manufactured using a combination of several assembly techniques so as to meet the requirements of sealing and mechanical strength while reducing power consumption and pollutant generation compared to brazing methods.

[0013] The invention thus relates to a heat regulating device, in particular a cooling device, for an electrical component that is susceptible to releasing heat during operation, in particular for an electrical energy storage module. The device comprises a first plate and a second plate assembled with the first plate, each plate being delimited by an edge so as to together form a plurality of flow channels for a heat transfer fluid, in particular a refrigerant fluid, the plurality of channels defining a channel area, at least one of the plates being pressed so as to form part of a wall of the channel, the two plates being assembled by transmission laser welding at the wall of the channel.

[0014] The device is characterized in that the area at least partially defining the perimeter of the channel area includes an assembly means feature different from transmission laser welding, and the different assembly means feature is selected from filler wire laser welding, adhesive bonding, friction stir welding, or a combination thereof.

[0015] “Assembled by laser welding at the channel region” means that the two plates are attached to each other at the channel in such a way as to allow a heat transfer fluid to circulate between the two components.

[0016] Advantageously, this assembly method, as opposed to transmission laser welding, makes it possible to improve the mechanical strength and reliability of the device while facilitating manufacturing by overcoming the drawbacks of transmission laser welding.

[0017] The charging device may also include one or more of the features described below, alone or in combination.

[0018] According to a particular feature of the invention, the area comprising the assembly means feature (8) defines the entire periphery of the passage area.

[0019] According to a particular feature of the invention, at least one channel wall defines a periphery of the channel area. Thus, "periphery of the channel area" means the channel wall furthest from the center of the device, and in particular the portion of the channel wall of a plate that joins another plate.

[0020] According to a particular feature of the invention, the periphery of the channel area, preferably the at least one channel wall defining at least a portion of the periphery of the channel area, comprises a weld formed by friction stir welding or adhesive bonding.

[0021] According to a particular feature of the invention, the periphery of the channel area, preferably said at least one channel wall defining at least a portion of the periphery of the channel area, comprises a weld formed by friction stir welding.

[0022] According to a particular feature of the invention, the periphery of the channel area, preferably said at least one channel wall defining at least a portion of the periphery of the channel area, comprises an adhesive bond.

[0023] According to a particular feature of the invention, the periphery of the channel area, preferably said at least one pressed channel wall defining at least a portion of the periphery of the channel area, defines the entire periphery of the channel area and forms a sealed channel comprising glue forming a seal.

[0024] According to a particular feature of the invention, the device comprises an additional weld, preferably formed by laser welding, outside the joint that delimits the perimeter of the passage area by different assembly means.

[0025] According to a particular feature of the invention, an additional weld, preferably formed by laser welding, joins at least the edge of at least one panel to another panel.

[0026] The invention also provides a method for assembling two plates in order to obtain a thermal conditioning device, in particular a cooling device, for an electrical component prone to releasing heat during operation, in particular for an electrical energy storage module, said method being characterized in that it comprises the following steps,

[0027] - providing two plates, each delimited by an edge, at least one of said plates being pressed so as to form a portion of a wall of said channel so as to form, together with the other plate, a plurality of circulation channels for a heat transfer fluid, in particular a refrigerant fluid, said plurality of channels defining a channel area,

[0028] - laser welding the two plates at the wall between the channels in contact with the second plate to form the channel area, said laser welding being preferably transmission laser welding,

[0029] - The perimeter of the channel area of ​​one plate is then joined to the other plate by assembly means other than transmission laser welding, preferably by joining at least one channel wall defining said perimeter.

[0030] According to a particular feature of the invention, the method also comprises a third step of joining around the joint at the periphery of the channel area by means of additional welds, preferably formed by laser welding, by different assembly means, in particular by welding the edge of at least one of the two plates to the other, preferably by laser welding.

[0031] According to a particular feature of the invention, the method further comprises a step of introducing glue that forms a seal in a pressed channel wall that defines the entire periphery of the channel area and forms a sealed channel, such that the glue is compressed by the two plates during their assembly, in particular followed by a step of heat treating the glue in the pressed wall once the plates of the device have been assembled and said glue has been compressed.

[0032] According to a particular feature of the invention, the method also comprises a step of heat-treating the glue in the pressed walls once the panels of the device have been assembled and said glue has been compressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Other characteristics and advantages of the invention will become more apparent on reading the following description provided by way of non-limiting illustrative example and in light of the accompanying drawings, in which:

[0034] Figure 1 A cooling device according to the prior art is shown schematically and partially;

[0035] Figure 2 A device according to a first embodiment of the invention is shown schematically and partially in a perspective view;

[0036] Figure 3 Schematically and partially shown in cross-section are details of a device according to a second embodiment of the invention,

[0037] Figure 4 shows schematically and partially in cross-section a detail of a device according to a third embodiment of the invention;

[0038] Figure 5 A detail of a device according to a fourth embodiment of the invention is shown schematically and partially in cross-section. DETAILED DESCRIPTION

[0039] Thermal regulation device

[0040] The invention relates in particular to a heat regulating device 3 described in more detail below. It comprises a heat regulating device, in particular a cooling device, for an electrical component (2) which is liable to release heat during operation, in particular for an electrical energy storage module, the device comprising a first plate (2) and a second plate (3) assembled with the first plate, each plate being delimited by an edge so as to form together a plurality of flow channels (5) for a heat transfer fluid, in particular a refrigerant fluid, the plurality of channels defining a channel area (6), at least one of the plates being pressed so as to form part of a wall of the channel, the two plates being assembled by transmission laser welding (7) at the wall of the channel,

[0041] The device is characterized in that an area at least partially defining the periphery of the channel area includes an assembly means feature (8) different from transmission laser welding (7), and the different assembly means feature (8) is selected from filler wire laser welding, adhesive bonding, friction stir welding, or a combination thereof.

[0042] Small communicating leaks between channels can be tolerated because there is no fluid loss to the outside of the cooler and only a negligible reduction in thermal uniformity at the cell surface. External leaks, regardless of their location, are unacceptable. One of the weaknesses of transmission laser welding is that it requires perfect contact between the surfaces to be welded.

[0043] Battery welding is typically performed from the inside of the cooler toward the outside to compensate for expansion and deformation of the plates caused by previous welding. This means the plate surfaces around the channel may deform, or maintaining contact between the two plates may become difficult, increasing the risk of leakage.

[0044] The mechanical constraints associated with battery coolers are increasing in number, and the mechanical behavior of the coolers has become a major issue.

[0045] One of the internal requirements was to keep cooler manufacturing cycle times as short as possible, so the joining between channels was always performed by transmission laser welding. The present invention is applied to the perimeter of the plate or in specific areas. Therefore, the present invention has the advantage of retaining the advantages of transmission laser welding while overcoming its disadvantages.

[0046] The charging device may also include one or more of the features described below, alone or in combination.

[0047] The size of the weld bead may be between 0.5 mm and 1.5 mm, preferably between 0.75 mm and 1.25 mm.

[0048] The position of the joint connecting the edge of one plate to the other depends on its position relative to the edge and on the position of the edge of the channel relative to the edge of the plate. The distance between the joint and the edge of the nearest plate can vary from 0 to 5 cm, preferably from 0.1 cm to 3 cm, more preferably from 0.1 cm to 1 cm.

[0049] It is to be understood here that the "edge" of the plate may be flat or pressed.

[0050] It should be understood that fillet joint welding is welding between the edge of one plate (preferably a pressed plate) and the flat area of ​​another plate (preferably an upper flat plate) without supplying material. A laser is used to melt the material of the plates in order to create a weld between them.

[0051] In the case of filler wire welding, for example, welding may be performed at the same location on the plates, but the filler wire is melted to provide the material that will form the weld bead.

[0052] In some embodiments, one of the plates has a deformation, such as a raised edge, which forms a fold towards the second plate. This advantageously makes it possible to reduce the risk that dust, debris or moisture can enter between the two plates.

[0053] It also advantageously makes it possible to reduce the influence of deformations due to the laser weld joint produced in the channel region.

[0054] Deforming the first pressed sheet to form the channel is typically done by pressing a deformed portion. The length of the deformed portion in the direction of the second sheet to which the first sheet is intended to join should not exceed the thickness of the second sheet. Laser welding generates stress when the sheets are joined, so a strong external weld is advantageous.

[0055] In some embodiments, laser welding is performed from the interior (eg, center) toward the exterior of the plate in order to be able to best manage the stresses generated by deformation and subsequent welding of the plate.

[0056] The glue may be selected from glue types such as PU (polyurethane), epoxy or methacrylate.

[0057] In some embodiments, the glue is cross-linked after it is applied in the device, for example by heat treatment, and the glue is made of EPDM, NBR or FKM.

[0058] In some embodiments, transmission laser welding is first performed between the channels, and then an additional secondary assembly means is performed, such as friction stir welding on the perimeter of the plate.

[0059] Friction stir welding is a solid-state welding method that involves assembling two parts while simultaneously reducing them to a mushy state using a rotating pin. An example of this method involves a cylindrical tool with a shoulder and a coaxial pin rotating at a constant speed across the contact line between the parts to be welded, causing the material to "soften," becoming mushy. The tool then penetrates into the plane of the joint and intimately mixes the materials. As the tool advances and gradually covers the entire area to be welded, a complete assembly is achieved. The maximum temperature reached during this method is below the melting temperature of the materials: friction stir welding is therefore a solid-state welding method.

[0060] In some embodiments, the apparatus includes a welding track that at least partially defines a fluid circulation area, and at least one weld bead (e.g., corresponding to an end of the welding track) is produced to contact the welding track at least at one contact point, the welding track and the weld bead having different curvatures relative to each other at the contact point.

[0061] By using a weld bead, the sealing of the cooling device is reliably ensured, and the stopping of the laser beam performing the welding does not affect the sealing of the cooling device. As will be described below, the weld bead can thus involve an additional welding operation that surrounds one end of the weld track and thus ensures a seal around the area with a potential leak, which is formed by the end of the weld track, or it can involve extending the weld track in order to offset the risk of leakage, which could potentially occur due to the stopping of the laser beam, into an area that is not a problem due to being far away from the fluid circulation area.

[0062] In some embodiments, the weld bead is constructed to at least partially contact the weld track and constitutes an additional weld that strengthens the cooling device's seal. In other words, the weld bead doubles the cooling device's seal by sealing the weld track. Consequently, the cooling fluid cannot flow through the potential weld track because the weld bead either closes the weld track, surrounding a potential weak point within the weld track, or extends the weld track to offset the weak point. In both cases, the seal is ensured and guaranteed by the different curvatures of the weld bead relative to the weld track at the point of contact between the weld bead and the weld track.

[0063] In some embodiments, the weld bead forms an extension of the weld track. In other words, the weld bead is continuous with the weld track, and the point of contact between the weld bead and the weld track corresponds to the junction between the end of the weld track and the beginning of the weld bead. This extension of the weld bead ensures sealing of the cooling device.

[0064] As mentioned above, the curvature varies from weld track to weld bead. Thus, starting from the contact point, the weld bead deviates from the path established by the weld track.

[0065] In some embodiments, the welding trajectory has a closed contour, and the weld bead has a free end at a distance from the closed contour of the welding trajectory.

[0066] For example, the closed contour defined by the weld track can correspond to the contour of the plate in order to prevent the cooling fluid from escaping the cooling device. Generally, for various reasons, the closed contour can define an area within which the cooling fluid should be contained, or conversely, an area into which the cooling fluid should not penetrate. The weld bead, for its part, extends until a free end, which deviates from the closed contour due to a curvature that differs from that of the weld track. This extension of the free end allows the laser beam to be interrupted at a certain distance from the end of the weld track, thereby avoiding the aforementioned sealing defects.

[0067] Figure 1 A prior art thermal conditioning device 1 is shown, which has a group of battery cells 12 to be cooled, for example aligned in two or more rows, which are in thermal contact with an upper plate 3 of the thermal conditioning device 1. The device 1 comprises a press plate 2 and a flat plate 3, between which a heat transfer fluid passes through channels. Most devices of this type are assembled by brazing in large furnaces, which presents several disadvantages, notably the cost of such furnaces and their carbon footprint during operation.

[0068] Figure 2 An example of an embodiment of a heat regulating device 1 is presented, comprising a first plate 2, which is preferably pressed, and a second plate 3, which is preferably flat. The channels 40 of the channel region 4 can be seen; they are configured to accommodate a heat transfer fluid flowing through said channels 40. One plate is attached to the other plate at the channel region 4 by transmission laser welding, while an assembly means (8), different from transmission laser welding (7), joins one plate (2, 3) to the other plate (2, 3) at the periphery of the channel region.

[0069] In some embodiments, such as by Figure 3 As shown by way of non-limiting example in FIG, the pressed plate 2 and the flat plate 3 are joined at the edges of the plates (in this case the pressed plate 2 ) by fillet joint laser welding or by filler wire laser welding.

[0070] Therefore, in some embodiments, the pressure plate 2 and the flat plate 3 are joined at the edge of one plate (in this case the pressure plate 2) on the other plate (in this case the flat plate 3) on a line at a certain distance from the edge of the flat plate 3 by an assembly means (8) different from laser welding (7).

[0071] Thus, the flat plate 3 extends beyond the edge of the other plate (the pressed plate 2 ).

[0072] This advantageously makes it possible to reduce the weight of the device, since the plate to which its edge is attached is smaller than the other plate. It also makes it possible to use a larger plate as a barrier to protect the joint from some impurities in the environment, so as to improve corrosion resistance.

[0073] In some embodiments, the second plate extends beyond the edge of the first plate (2) by a length of at least 1 mm, preferably at least 1.5 mm.

[0074] This advantageously makes it possible, in particular, to reduce the weight of the device while benefiting from corrosion protection, and to do so optimally.

[0075] In some embodiments, as Figure 4 As shown in the non-limiting example in FIG, one of the two plates comprises a pressed section 8 surrounding the channel area, such as the pressed plate 2.

[0076] Thus, said pressing section 8 may comprise an adhesive element 10, such as glue, in order to ensure the bond between the two panels and the sealing of the assembly.

[0077] In some embodiments (not shown), the device comprises an adhesive element 10 , for example glue, without an additional pressing section 8 .

[0078] In some embodiments, such as by Figure 4 and Figure 5 As shown in the non-limiting example of , one of the two plates (for example the pressed plate 2) comprises a pressed section 11 around the channel area, the pressed section 11 forming the periphery of the channel area, the device comprises a seal 9 or an adhesive 10 forming the seal 9, which is compressed between the two plates (2, 3), the seal 9 being placed in the space formed by the pressed section 11 between the two plates (2, 3).

[0079] The pressed section 11 is preferably delimited on at least one side by an additional laser weld joining the two plates. The joint may be between the seal 9 and an edge of at least one plate and may be produced, for example, by transmission laser welding.

[0080] In some embodiments, the length e of the joining device 8 formed by the pressed section 11 comprising the adhesive 10 or the seal 9 and the length e of the additional laser weld between the seal 9 and the edge of at least one panel is greater than 3 mm.

[0081] In some embodiments, the height of seal 9 is at least 1.5 mm.

[0082] It will be understood that the lengths e1 , e2 , e3 , e4 , e5 and e6 are measured at a given point in a direction perpendicular to the main direction and extending at that point.

[0083] In some embodiments, the height of the pressed section 11 is at least 3 mm.

[0084] The inner structure of the seal 9 may be modified after it has been placed in the pressing section 11 , for example by heat treatment.

[0085] Reference Signs List

[0086] 1. Heat regulation device

[0087] 2. First board, pressing

[0088] 3. Second flat plate, flat

[0089] 4. Channel area

[0090] 40. Channel

[0091] 5. Deformation portion forming the folded portion

[0092] 6. Connectors

[0093] 7. Transmission laser welding

[0094] 8. Different assembly methods

[0095] 9. Seals

[0096] 10. Adhesive

[0097] 11. Pressing part

[0098] 12. Components, storage devices, electrical parts

[0099] E. Fluid inlet

[0100] S. Fluid outlet

Claims

1. A heat regulating device (1), in particular a cooling device, for an electrical component (2) which tends to release heat during operation, in particular for an electrical energy storage module, the device comprising a first plate (2) and a second plate (3) assembled with the first plate, each plate being delimited by an edge so as to form together a plurality of flow channels (5) for a heat transfer fluid, in particular a refrigerant fluid, the plurality of channels defining a channel area (6), at least one of the plates being pressed so as to form a part of a wall of the channel, the two plates being assembled by transmission laser welding (7) at the wall of the channel, The device is characterized in that an area at least partially defining the periphery of the channel area includes an assembly means feature (8) different from transmission laser welding (7), and the different assembly means feature (8) is selected from filler wire laser welding, adhesive bonding, friction stir welding, or a combination thereof.

2. Thermal conditioning device (1) according to the preceding claim, wherein At least one channel wall defines a perimeter of the channel region.

3. A heat conditioning device (1) according to any one of the preceding claims, wherein The periphery of the channel region, preferably the at least one channel wall defining at least a portion of the periphery of the channel region, comprises a weld formed by friction stir welding.

4. A heat conditioning device (1) according to any one of the preceding claims, wherein The periphery of the channel area, preferably the at least one channel wall defining at least a portion of the periphery of the channel area, comprises a bonded joint.

5. A heat conditioning device according to any one of the preceding claims, wherein: The periphery of the channel area, preferably the at least one pressed channel wall defining at least a portion of the periphery of the channel area, defines the entire periphery of the channel area and forms a sealed channel comprising glue forming a seal.

6. A heat conditioning device according to any one of the preceding claims, wherein: The device comprises an additional weld, preferably formed by laser welding, which defines the outside of the joint of the periphery of the passage area by means of the different assembly means features.

7. A heat conditioning device according to any one of the preceding claims, wherein: The additional weld joins at least an edge of at least one panel to another panel, preferably by laser welding.

8. A method for assembling two plates in order to obtain a heat conditioning device, in particular a cooling device, for an electrical component prone to releasing heat during operation, in particular an electrical energy storage module, characterized in that it comprises the following steps: - providing two plates, each delimited by an edge, at least one of said plates being pressed so as to form a portion of a wall of said channel so as to form, together with the other plate, a plurality of circulation channels for a heat transfer fluid, in particular a refrigerant fluid, said plurality of channels defining a channel area, - transmission laser welding of the two plates at the wall between the channels in contact with the second plate to form the channel area, - The perimeter of the channel area of ​​one plate is then joined to the other plate by assembly means other than transmission laser welding, preferably by joining at least one channel wall defining said perimeter.

9. Assembly method according to the preceding claim, further comprising a third step of performing a joining around the joint at the periphery of the channel area by means of additional welds, preferably formed by laser welding, by means of the different assembly means, in particular by welding the edge of at least one of the two plates to the other plate, preferably by laser welding.

10. Assembly method according to any one of claims 8 and 9, further comprising a step of introducing glue and forming a sealing channel, said glue forming a seal in a pressed channel wall defining the entire periphery of said channel area, so that said glue is compressed by said two plates during assembly, in particular followed by a step of heat treating said glue in said pressed wall once said plates of said device have been assembled and said glue has been compressed.

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