Cooling device

Abstract

The invention relates to a cooling device (30) for at least one element to be cooled, for example at least one electric battery element, the cooling device (30) comprising: - at least one flexible wall (36), and - at least one flow channel (52) for heat-transfer fluid delimited at least partially by the at least one wall (36), the at least one wall (36) being configured to be placed in contact with the at least one element to be cooled, between the channel (52) and the at least one element to be cooled, - at least one active temperature-control element (60), configured to supply a controlled thermal power at least to the fluid contained in the at least one channel (52), arranged on an inner surface (64) of the at least one wall (36), on an outer surface (66) of the at least one wall (36), or in the thickness of the at least one wall (36).

Description

[0001] DESCRIPTION

[0002] TITLE: Cooling Device

[0003] Technical field of the invention

[0004] The invention relates to a cooling device for at least one element to be cooled, for example at least one electric battery element.

[0005] The invention also relates to an electric battery comprising such a cooling device.

[0006] Prior art

[0007] In a multi-cell battery, that is, a battery comprising several independent battery cells grouped within a casing, the hottest cells are located in the center. Since the cells are generally arranged side-to-side to reduce overall size, the heat generated by these most enclosed cells is dissipated only through their undersides. The electrical connectors between these different battery cells are usually located on the top surfaces and are also likely to generate significant heat.

[0008] Indirect fluid cooling is the most common method used by manufacturers because it is efficient, relatively simple to implement, and inexpensive. This method involves circulating a heat transfer fluid, or cooling fluid (usually a water-glycol mixture), through a cooling system located beneath the battery cells. The fluid acts as a heat transfer fluid, removing thermal heat from the battery and dissipating it outside the enclosure as it circulates. Consequently, heat dissipation is highly dependent on the thermal resistance between the electrical connectors or the underside of the battery cells (depending on the application) and the cooling system.

[0009] To improve this thermal exchange resistance, it is known to use thermal interface materials, such as thermally conductive resins, between the cold plate of the cooling device and the undersides of the battery cells or the complex structures of the connectors. This bridges the local gaps between these surfaces caused by the asperities and roughness of these solid structures. However, such a solution significantly increases the cost and mass of the battery. Furthermore, the thermal contact achieved through the use of such an interface material remains considerably less efficient than direct mechanical contact between conductive metallic materials.Another possibility for improving thermal contact is the use of a flexible, deformable wall, particularly in a flexible envelope for the circulation of the heat transfer fluid, instead of a rigid structure. The flexible wall deforms freely under the effect of the circulation pressure of the heat transfer fluid and thus conforms to the contours of the underside of the battery elements or electrical connectors, thereby providing good thermal contact.

[0010] For example, a flexible envelope of the aforementioned type is designed using two sheets of multi-material, multi-layered film joined by local welding to form one or more fluid circulation channels. The two sheets can be separate or formed from a single sheet folded over itself.

[0011] Such a flexible casing thus allows for a cooling device that benefits from good thermal contact with the battery elements to be cooled, while being lightweight and simple to manufacture compared to previous rigid coolers.

[0012] The implementation of such a flexible envelope for cooling battery elements is described for example in patent applications FR2311874 and FR2311875 or FR2405865.

[0013] There are other types of cooling devices that include a flexible wall forming the thermal interface between the heat transfer fluid and the elements to be cooled, which are not necessarily limited to battery elements.

[0014] However, such a cooling system, which includes a flexible wall delimiting the heat transfer fluid circulation duct, can still be improved. Indeed, controlling the efficiency of fluid circulation cooling is difficult, primarily due to the lack of options for correcting potential cooling inefficiencies. For example, a fluid temperature that is too low can, counterintuitively, cause cooling problems by significantly increasing the fluid's viscosity, or even causing a freeze-thaw phase change, which prevents proper circulation in certain areas of the duct and reduces the uniformity of the cooling.

[0015] Presentation of the invention

[0016] The invention aims to improve control of the homogeneity of the heat transfer fluid circulation within the circulation duct. Thus, the invention proposes a cooling device for an electric battery, employing a flexible interface wall as described above and enabling active temperature control, and therefore, in particular, control of the viscosity of the fluid circulating in the duct. To this end, the invention relates to a cooling device for at least one element to be cooled, for example, at least one electric battery cell, the cooling device comprising:

[0017] - at least one flexible wall, and

[0018] - at least one heat transfer fluid circulation duct delimited at least in part by said at least one wall, said at least one wall being configured to be placed in contact with the at least one element to be cooled, between said duct and the at least one element to be cooled, characterized in that the cooling device further comprises:

[0019] - at least one active thermoregulation element, configured to deliver controlled thermal power at least to the fluid contained in at least one duct, said at least one active thermoregulation element being disposed on an internal surface of at least one wall, an external surface of at least one wall, or in the thickness of at least one wall.

[0020] Such a cooling system allows for local adjustment of the fluid temperature, raising or lowering it, to improve fluid circulation within the casing and ensure more even cooling. Temperature control is thus achieved as close as possible to the fluid cooling the battery cells, thereby improving its efficiency.

[0021] The cooling device may include at least one fluid inlet connector and at least one fluid outlet connector of the casing, opening into at least one fluid circulation duct.

[0022] At least one active thermoregulation element may include at least one electrical resistance or at least one Peltier effect cell.

[0023] Such a characteristic makes it possible to realize the active thermoregulation element in a simple and robust manner, and, in the case of Peltier cells, to provide negative thermal power.

[0024] At least one active thermoregulation element may be disposed on the internal surface, the external surface or in the thickness of at least one wall intended to be placed in contact with the elements to be cooled, preferably so that the active thermoregulation element is placed in the vicinity of or in contact with at least one of the elements to be cooled.

[0025] This feature allows the fluid temperature to be regulated as close as possible to the critical points for battery cooling.

[0026] The cooling device may include at least two flexible walls enclosing at least one duct, with at least one active temperature control element disposed on the inner surface, outer surface, or within the thickness of one of said walls, intended to be positioned on the side opposite the elements to be cooled, preferably on the inner surface of that wall. This feature allows for more effective control of the fluid temperature in the area most at risk of becoming too cold. The cooling device may include a plurality of active temperature control elements configured to operate independently of one another.

[0027] Such a feature allows the temperature regulation to be adapted to local conditions in the duct, providing more heat to areas that are too cold without providing it to areas that do not require it.

[0028] The active thermoregulation elements can be distributed along at least one fluid circulation duct.

[0029] Such a feature allows the fluid flow to be regulated at every point along the path in the conduit.

[0030] The cooling device may further include at least one sensor configured to measure a property of the heat transfer fluid and / or of an environment of the cooling device.

[0031] Such a feature makes it possible to obtain local information on the state of cooling in order to control the thermoregulation elements more precisely.

[0032] At least one sensor can be disposed on the internal surface, the external surface or in the thickness of at least one wall.

[0033] This feature allows for the detection of abnormal conditions within the enclosure, such as overheating, leaks, or excessive condensation. In the case of a temperature sensor, this sensor can be positioned on the casing to be near at least one battery cell in order to measure the cell's temperature.

[0034] Alternatively, a temperature or humidity sensor can be positioned on the casing to be away from the battery elements, so as to reduce the impact of the battery elements on the measurement.

[0035] The at least one sensor may include at least one temperature sensor and / or at least one humidity sensor, preferably located on the external surface of at least one wall.

[0036] Such a feature makes it possible to measure the temperature of the fluid circulating in the casing while minimizing the disturbance of the measurement by the battery elements.

[0037] The cooling device may include at least two flexible walls delimiting at least one duct, at least one sensor including at least one temperature sensor disposed on one of said walls, intended to be placed on the side of the envelope opposite the elements to be cooled, preferably on an internal surface of that wall.

[0038] Such a feature makes it possible to measure the temperature of the fluid in the conduit while reducing the measurement disturbance due to the proximity of the elements to be cooled. At least one sensor may include at least one hydrostatic pressure sensor and / or at least one viscosity measurement sensor, preferably arranged on the internal surface of at least one wall, so as to be in contact with the fluid.

[0039] Such a characteristic makes it possible to detect irregularities in fluid flow that would not be apparent simply by measuring the fluid temperature.

[0040] The cooling device may include at least one conductive track extending over the internal surface, the external surface or within the thickness of at least one wall, said at least one conductive track being configured to connect the at least one active thermoregulation element and, where applicable, the at least one sensor, to a remote control unit.

[0041] This feature allows active thermoregulation elements and sensors to be controlled and powered from a remote control unit.

[0042] The invention also relates to an electric battery comprising:

[0043] - a plurality of battery cells arranged in an enclosure, each battery cell having cooling elements arranged on an upper, lower, or lateral face of the battery cell, and

[0044] - a cooling device as described above,

[0045] the flexible envelope being arranged to come into contact with the elements to be cooled when a cooling fluid circulates in at least one circulation conduit.

[0046] Brief description of the figures

[0047] Figure 1 is a schematic cross-sectional view of an electric battery comprising a cooling device according to the invention.

[0048] Figure 2 is a perspective view of the cooling device in Figure 1.

[0049] Figure 3 is a cross-sectional view of the cooling device of Figure 2. Figure 4 is a cross-sectional view of an active thermoregulation element placed on an inner face of a sheet of an envelope of the cooling device of Figures 2 and 3.

[0050] Figure 5 is a cross-sectional view of an active thermoregulation element placed within the thickness of a sheet of the casing of the cooling device in Figures 2 and 3.

[0051] Figure 6 is a cross-sectional view of an active thermoregulation element placed on an outer face of a sheet of the housing of the cooling device of Figures 2 and 3.

[0052] Detailed description of the invention Figure 1 represents an electric battery 10 intended for energy storage, intended in particular for applications on board a vehicle, for example an electric or hybrid powered vehicle.

[0053] The said vehicle is, for example, a motor vehicle, a road or rail transport vehicle, a maritime vehicle, or other.

[0054] Alternatively, battery 10 is intended for a fixed or mobile installation requiring an electrical power supply, without connection to the power grid, or as a supplement to it.

[0055] The battery comprises a closed enclosure 12, substantially sealed, and a plurality of battery elements 14, or cells, arranged in the enclosure 12 and suitable for storing electrical energy.

[0056] The enclosure 12 includes a removable top cover 15 to allow access to the battery elements 14. The enclosure 12 also defines openings 16 in one of the walls, through which are placed pipes 17 for circulating heat transfer fluid, or cooling fluid, which allows the supply of cooling fluid through the walls of the enclosure, from an external reservoir equipped with a circulation pump (not shown).

[0057] Each battery element 14 has a general shape that is substantially parallelepiped-shaped and thus defines an upper face 18, a lower face 20 and four lateral faces.

[0058] The terms "upper" and "lower" are understood here in relation to a standard positioning of the battery under operating conditions.

[0059] The battery elements 14 are arranged aligned in at least one row extending along an alignment direction X. An elevation direction Z and a transverse direction Y are further defined, both perpendicular to each other and perpendicular to the alignment direction X, the elevation direction Z being oriented substantially vertically in a standard operating orientation of the battery 10.

[0060] The battery elements 14 can be arranged in contact with each other by their respective lateral faces, along the alignment direction X, or with small gaps between two neighboring battery elements along the alignment direction X.

[0061] Each battery element 14 has connectors arranged on its upper face 18, on either side of said upper face 18 along the transverse direction Y. The connectors of the battery elements 14 thus form two rows extending along the alignment direction X.

[0062] The connectors of the battery cells 14 are connected to parallel bus bars 24 which extend substantially along the X alignment direction, allowing energy to be supplied to the battery cells 14 for storage or energy to be withdrawn from the battery cells to power an electrical device. The battery 10, and more specifically the battery cells 14, generate heat during operation and require cooling for optimal performance, service life, and satisfactory safety.

[0063] For this purpose, the battery 10 includes at least one cooling device 30 for the battery elements to be cooled, also shown in more detail in figures 2 to 4.

[0064] The elements to be cooled may be the battery cells 14, and more specifically the lower faces 20 or lateral faces of the battery cells, or the connectors of the battery cells as well as the bus bars 24, which are arranged above the upper faces of the battery cells.

[0065] In the example shown in the figures, the cooling device 30 is arranged to cool the battery element connectors and the bus bars 24, and is positioned in the enclosure 12, suspended from the cover, above the battery elements 14. The cooling device 30 includes a flexible casing 32 for receiving the heat transfer fluid which circulates to cool the battery elements 14.

[0066] Advantageously, the cooling device 30 also includes a support structure 34 adapted to improve the rigidity and strength of the cooling device 30.

[0067] The support structure 34 includes, for example, a rigid frame configured to enclose the lateral edges of the flexible envelope 32 in order to hold it.

[0068] The terms "rigid" and "flexible" are used here in a relative sense. Furthermore, the flexibility of the casing 32 implies that, without external action, the casing deforms under its own weight, whereas the rigidity of the support structure 34 implies that it does not undergo significant deformation under its own weight.

[0069] The frame is, for example, substantially rectangular and encloses the external lateral edges of the envelope 32. Said frame is, for example, made of plastic by molding, stamping, or according to an additive manufacturing process.

[0070] Advantageously, the support structure 34 further includes suitable fastening means for fixing the support structure 34 to the cover or walls of the enclosure 12 of the electric battery.

[0071] The fastening means are, for example, positioned along the outer edge of the frame.

[0072] The fastening means can also or alternatively be adapted to fix the support structure 34 to the battery elements 14, in particular to the lower 20, lateral or upper 18 faces of the battery elements 14.

[0073] The means for fixing the support structure 34 are, for example, snap-fit ​​means, screw-fit means, or articulated means. Alternatively, the support structure 34 can be fixed to the side faces of the enclosure 12 or to the bottom of the enclosure 12, so as to bring the casing 32 into contact with the side or bottom faces, respectively, of the battery elements 14.

[0074] Alternatively, the enclosure 32 can simply be placed on the bottom of the enclosure 12, in contact with the lower faces of the battery elements, and not be further supported by a support structure 34.

[0075] According to an unrepresented variant, the rigid frame is replaced by a semi-rigid plate, for example made of polymer foam, to which the flexible cover 32 is attached by gluing, bolting, and / or snapping.

[0076] The envelope 32 is for example formed of two sheets of flexible material extending opposite each other and partially welded to each other, said sheets thus forming two flexible walls 36 opposed to each other.

[0077] Thus, the envelope 32 has welding regions 38, in which the walls 36 are joined together, and separation regions 40, in which the walls 36 are not welded together and are thus able to extend the gap between them, defining an internal space between them.

[0078] The weld regions 38 follow in particular an external contour of the envelope 32, so as to make an internal space of the envelope 32 watertight.

[0079] According to an unrepresented variant, the support structure 34 includes, in addition to or instead of the rigid frame, a rigid intermediate structure, for example formed of a substantially flat plate with openings, which extends between the walls 36 of the envelope 32, in particular at their lateral edges.

[0080] The weld regions 38 are formed by welding the two walls 36 on opposite sides of the intermediate structure, along the lateral edges and, optionally, on at least one central region of the intermediate structure. The separation regions 40 extend between the weld regions 38, where the walls are not fixed to the intermediate structure.

[0081] The walls 36 are therefore fixed along the lateral edges on either side of the intermediate structure and define two internal spaces on either side of said intermediate structure.

[0082] The openings in the intermediate structure are defined between the said weld regions 38, in the separation regions 40, so as to connect the internal spaces defined between the respective walls 36 and the intermediate structure, to allow the circulation of the fluid.

[0083] Advantageously, said openings cover at least 50% of the surface of the intermediate structure, and preferably at least 70% of said surface. According to an alternative not shown, the casing 32 comprises at least one rigid or semi-rigid part to which is attached at least one flexible wall 36 as described above. Said at least one flexible wall is attached to the rigid or semi-rigid parts by weld regions in order to close the internal space and is adapted to move away from these rigid or semi-rigid parts in a deformable manner in separation regions extending between the weld regions to delimit the conduit 52.

[0084] The 36 flexible walls are formed from sheets made from a multilayer film cut to obtain the desired geometry.

[0085] The term "sheet" is used here in a broad sense, and includes cases where each sheet is an independent piece, cases where each of the two sheets is composed of several pieces initially separate and fixed together to form a sheet. These sheets may also be formed from two parts of a single, larger sheet folded over itself along at least one fold line to form the envelope 32, each sheet then being defined by said fold line and its free edges.

[0086] The film, for example, is a stack of layers such as: a first layer of polyethylene terephthalate (PET), a layer of aluminum (Al), a second layer of polyethylene terephthalate, and a layer of polyethylene (PE). This type of film is commonly used in the food industry for effective product insulation.

[0087] In the case of the 32 envelope, the aluminum layer provides very good thermal conductivity and reduces the risks of fluid permeation through the sheets, the polyethylene terephthalate layers provide good resistance to temperature and ambient environment, and the polyethylene layer serves as an adhesive layer, for fixing the two sheets by melting the two polyethylene layers in contact with each other.

[0088] In the example shown, the envelope 32 has a substantially rectangular shape. The rectangular shape of the envelope 32 includes, for example, two long sides 44, which extend along the alignment direction X, and two short sides 46, which extend along the transverse direction Y.

[0089] The envelope 32 defines lateral edges, in particular external lateral edges extending along the long sides 44 and the short sides 46.

[0090] The enclosure 32 defines an inner face 47, which is oriented towards the inside of the enclosure 12 and intended to be in contact with the battery elements 14, and an outer face 48, oriented in the opposite direction to the battery elements 14.

[0091] In general, in different embodiments of the enclosure 32 described above, the inner face 47 is always formed by a flexible wall 36 in order to allow close contact with the battery elements.

[0092] The external face 48 can be rigid or semi-rigid and formed by the rigid or semi-rigid parts of the envelope mentioned above. Preferably, the external face 48 is also flexible and formed of a wall 36 like the internal face 47.

[0093] The cooling device 30 further comprises at least one inlet fluid connector 50 and at least one outlet fluid connector 50, arranged in the casing, and at least one fluid circulation conduit 52, shown in Figure 3, delimited by at least one flexible wall 36 and, preferably, by the two walls 36 of the casing 32, from at least one inlet connector 50 to at least one outlet connector 50. In Figure 3, the circulation flow of the heat transfer fluid is represented by arrow F.

[0094] The separation regions 40 between the walls 36 together delimit said at least one fluid circulation conduit 52 in the internal space.

[0095] In the example shown, the inlet and outlet fluidic connectors 50 are positioned on the same side of the rectangular shape of the envelope 32.

[0096] For example, the two fluidic connectors 50 are positioned on the same short side 46 of the rectangular shape of the envelope 32, that is to say at the level of the same end of the envelope 32 along the alignment direction X, and on either side of said rectangular shape along the transverse direction Y.

[0097] In the example shown, the enclosure 32 includes a single fluid circulation conduit 52 having a U-shape, i.e. the conduit 52 extends from the inlet connector 50 along one of the long sides 44, then along the short side 46 opposite the connectors 50, and along the other of the long sides 44 to the outlet connector.

[0098] More generally, the conduit 52 extends along a path forming at least one round trip on the envelope 32, in order to run alongside the two rows of connectors of the battery elements 14 and to allow the fluidic connection of the inlet and outlet at the same lateral edge of the envelope 32.

[0099] Thus, conduit 52 can have a V-shape, a W-shape, etc...

[0100] The conduit 52 can also extend along a meandering path over the extent of the envelope 32, i.e. forming at least one bend, for example in an S shape, which allows the cooled surface to be increased.

[0101] Alternatively, the envelope 32 may comprise several conduits 52 extending divergently from at least one inlet point and converging at at least one outlet point. Alternatively still, the envelope 32 may comprise a plurality of conduits 52 fluidically separated from one another.

[0102] In particular, the casing 32 may comprise two substantially straight and parallel conduits 52 extending along the two rows of connectors and the bars 24, in the alignment direction X. The fluid connectors 50 are arranged in respective inlet or outlet ports formed in the sheets forming the casing 32, so as to establish fluid communication between the circulation conduits 52 and the heat transfer fluid circulation pipes. According to an alternative embodiment not shown, the fluid connectors 50 may be fixed to the frame, engaged in corresponding ports formed in the frame, or even be defined directly within the frame structure.

[0103] According to the invention, the cooling device 30 further comprises at least one active thermoregulation element 60 disposed on the flexible casing 32.

[0104] The active thermoregulation element 60 is designed to deliver thermal power, in a controlled manner, to supply heat to its immediate surroundings or to remove heat from its immediate surroundings, for example, to raise or lower their temperature. The term "thermal power" is therefore understood algebraically and can represent a negative value (removal of heat, or calories) or a positive value (addition of heat, or calories).

[0105] Thermal power is delivered in particular at least to the heat transfer fluid which circulates in the duct 52.

[0106] For example, each active thermoregulation element 60 may include at least one electrical resistor, capable of delivering heat by Joule heating when an electrical voltage is applied across its terminals, or at least one Peltier cell, capable of delivering or removing heat by Peltier heating when a voltage is applied between its electrodes. The addition of thermal energy to the heat transfer fluid allows for the correction, preferably locally, of excessively low fluid temperatures that would excessively increase its viscosity and impede proper fluid flow.

[0107] The removal of calories allows the fluid and / or the internal environment of enclosure 12 to be cooled locally, to prevent the formation of hot spots.

[0108] Each active thermoregulation element 60 is disposed on an internal surface 64, an external surface 66 or in the thickness of one of the walls 36 of the flexible envelope 32.

[0109] Each active thermoregulation element 60 is connected to a remote control unit (not shown), by means of at least one conductive track 62, which extends over the internal surface 64, the external surface 66, or in the thickness of the wall 36.

[0110] An active thermoregulation element 60 placed on the internal surface 64 is intended to be in direct contact with the fluid, improving the efficiency of heat transfer between the active thermoregulation element and the fluid.

[0111] Furthermore, each active thermoregulation element 60 can be placed on the wall 36 forming the inner face 47 and intended to be in contact with the battery elements 14, as shown in Figures 4 to 6, or on the wall 36 forming the outer face 48 of the casing 32, in embodiments where it is present. A first arrangement is shown in Figure 4, which displays the active thermoregulation element 60 and the conductive track 62 arranged on the inner surface 64 of the wall 36, the various layers of which are shown. The thermoregulation element 60 is in contact with the heat transfer fluid flow F in the duct 52, and allows its temperature to be modified locally.

[0112] The active thermoregulation element 60 is disposed on the inner face 47, at a region of the wall 36 in contact with a battery element 14, for example a battery element connector 14, in order to control the temperature of the fluid at this critical point.

[0113] Alternatively, when the active thermoregulation element 60 is disposed on the outer face 48 of the casing 32, on the side opposite the battery elements 14, the thermoregulation implemented is better concentrated on the fluid and receives less thermal disturbance from the battery elements 14.

[0114] Alternatively, the active thermoregulation element 60 can extend from the internal surface 64 of the wall 36 into the internal space of the casing 32 and, advantageously, along the duct 52, in the manner of a heating wire, for example. Such a thermoregulation element makes it possible to supply thermal power directly to the core of the heat transfer fluid.

[0115] An active thermoregulation element 60 placed on the external surface 66 of the wall 36 is directly exposed to the internal environment of the enclosure 12, and depending on its position, in the vicinity or in contact with the battery elements 14, which improves the heat transfer from the active thermoregulation element 60 to said environment and, where applicable, the battery elements 14.

[0116] Such an arrangement is shown in Figure 5, which shows the active thermoregulation element 60 and the conductive track 62 arranged on the external surface 66 of the wall 36, on the side opposite the flow F of heat transfer fluid in the duct 52.

[0117] In this figure, the active thermoregulation element is positioned upstream of the wall region 36, resting on the battery element 14.

[0118] Finally, an active thermoregulation element 60 placed in the thickness of the wall 36, that is to say, in the case where said wall 36 is made from a multilayer film sheet, placed between two of the constituent layers of the sheet, is isolated from the heat transfer fluid and the internal environment of the enclosure 12, which improves its protection and durability.

[0119] Such an arrangement is shown in Figure 6, which shows the active thermoregulation element 60 and the conductive track 62 arranged between the PE layer and the first PET layer of the sheet forming the wall 36. Advantageously, several active thermoregulation elements 60 are arranged on the inner face 47 and / or the outer face 48 of the envelope 32, said active thermoregulation elements 60 being configured to operate independently of each other.

[0120] For this purpose, each active thermoregulation element 60 is connected to the control unit by at least one conductive track 62 which is its own and is controlled independently by said control unit, for example by means of a specific control voltage transmitted by said track.

[0121] Advantageously, several such active thermoregulation elements 60 are distributed along at least one fluid circulation conduit 52. This makes it possible to localize the thermoregulation effect at different points along the heat transfer fluid path, in order to locally correct thermal imbalances in the fluid.

[0122] In the example shown in Figure 2, four such active thermoregulation elements 60 are arranged distributed along the fluid circulation conduit 52, in a substantially regular manner over the length of the conduit 52. These active thermoregulation elements 60 are controlled and activated independently of each other, in order to homogenize the temperature profile of the fluid along the conduit 52.

[0123] Advantageously, the cooling device further includes at least one sensor 70 disposed on at least one of the walls 36.

[0124] The sensors 70 can be arranged on the wall 36 forming the outer face 48 of the casing 32 or on the wall 36 forming the inner face 47 of the casing 32, in contact with the battery elements 14. The sensors 70 can be arranged on the inner surface 64 of the wall 36, on the outer surface 66 of the wall 36, or within the thickness of the wall 36, depending on the type of sensor and the quantity being measured. The arrangement of the sensors 70 relative to the wall 36 is substantially identical to that of the active thermoregulation elements 60 described above.

[0125] Each 70 sensor is designed to measure at least one quantity of its environment, for example temperature, pressure, humidity, or other.

[0126] Each sensor 70 is connected to the remote control unit (not shown), by means of at least one conductive track 72, which extends over the internal surface 64, the external surface 66, or in the thickness of the wall 36.

[0127] For example, each sensor 70 can be arranged to measure the quantity inside the casing 32, in particular in the heat transfer fluid, outside the casing 32, in particular at the battery elements 14, or both inside and outside the casing 32.

[0128] The sensor 70 can, for example, be a temperature sensor, allowing the detection of a temperature that is too high, or too low in the case of the heat transfer fluid, and thus correcting this abnormal temperature by activating one or more of the active thermoregulation elements 60.

[0129] For example, a temperature sensor 70 can be placed on the internal surface 64, in contact with the heat transfer fluid, to measure the temperature of the fluid, on the internal face 47 of the casing 32, close to the elements to be cooled, or on the external face 48 of the casing, which receives less heat in operation.

[0130] In particular, such a sensor 70 placed on the outer face 48 of the casing 32 is further away from the battery elements and can therefore measure the properties of the heat transfer fluid and its ability to circulate efficiently, with less disturbance due to the nearby presence of the battery elements 14.

[0131] The sensor 70 can also extend from said internal surface 64 of the wall 36, through the internal space and, advantageously, along the circulation conduit 52, in the manner of a wired sensor.

[0132] Such a temperature sensor 70 can also be placed on the external surface 66 of the wall 36, in contact with the internal space of the enclosure 12 or in direct contact with the battery elements 14, to measure their temperature.

[0133] Such a temperature sensor 70 can also be positioned within the thickness of the wall 36 to improve the durability of the sensor 70, without significantly affecting the temperature measurements due to the thinness of the wall 36 and its good thermal conductivity. Alternatively, at least one of the sensors 70 can be a hydrostatic pressure sensor. Such a pressure sensor 70 can preferably be positioned on the inner face of the wall 36 so as to measure the hydrostatic pressure of the fluid flowing in the conduit 52 and thus detect, for example, overpressure or excessive fluid viscosity. Alternatively, one of the sensors 70 can be a humidity sensor.

[0134] Such a hygrometry sensor can be preferentially placed on the external surface 66 of the wall 36, in order to measure a humidity level in the enclosure 12, in order to detect a leak or excessive condensation.

[0135] The sensors 70 allow for fine-tuning, preferably locally, the control of the active thermoregulation elements 60 in order to better correct temperature and viscosity variations of the heat transfer fluid.

[0136] Preferably, the sensors 70 are distributed along the fluid circulation conduit 52, for example alternately with the active thermoregulation elements 60, as shown in Figure 2.

[0137] Alternatively, in addition to or instead of such sensors 70, it is possible to measure the temperature of the fluid at the outlet of the enclosure 12, in the pipes 17, the pressure drop following passage through the conduit 52, the variation of the inlet and outlet fluid flow rates, etc., in order to control the activation of the active thermoregulation elements 60. The sensors 70 and the thermoregulation elements 60 can be fixed to the walls 36 or in the thickness of the walls 36, for example by gluing or welding.

[0138] Alternatively, the sensors 70 and the thermoregulation elements 60 can be directly deposited by in-situ manufacturing using additive manufacturing, inkjet printing or vapor phase deposition processes.

[0139] These different techniques can be used alone or in combination, depending on the type of sensor 70 or thermoregulation element 60.

[0140] Other embodiments of the cooling device 30 may include flexible walls 36 of different types than the film sheets described above, as long as these walls have good thermal conductivity and are deformable to allow good thermal contact with the elements to be cooled.

[0141] Other geometries can also be considered to replace the flexible envelope 32, including for example rigid or semi-rigid parts on which the flexible wall 36 forming the thermal interface is fixed.

[0142] Finally, the example described falls within the preferred framework of cooling electric battery elements, but the cooling element 30 can find application in many technical fields requiring local cooling, particularly within a closed enclosure, for example in computer systems.

Claims

DEMANDS 1. Cooling device (30) for at least one element to be cooled, for example at least one electric battery cell, the cooling device (30) comprising: - at least one flexible wall (36), and - at least one heat transfer fluid circulation duct (52) delimited at least in part by said at least one wall (36), said at least one wall (36) being configured to be placed in contact with the at least one element to be cooled, between said duct (52) and the at least one element to be cooled, characterized in that the cooling device (30) further comprises: - at least one active thermoregulation element (60), configured to deliver controlled thermal power at least to the fluid contained in at least one conduit (52), said at least one active thermoregulation element (60) being disposed on an internal surface (64) of at least one wall (36), an external surface (66) of at least one wall (36), or in the thickness of at least one wall (36).

2. Cooling device (30) according to claim 1, wherein at least one active thermoregulation element (60) comprises at least one electrical resistance or at least one Peltier effect cell.

3. Cooling device (30) according to claim 1 or 2, wherein at least one active thermoregulation element (60) is disposed on the internal surface (64), the external surface (66) or in the thickness of at least one wall (36) intended to be placed in contact with the elements to be cooled, preferably so that the active thermoregulation element (60) is placed in the vicinity of or in contact with at least one of the elements to be cooled.

4. Cooling device (30) according to claim 1 or 2, wherein the cooling device (30) comprises at least two flexible walls (36) delimiting at least one conduit (52), at least one active thermoregulation element (60) being disposed on the inner surface (64), the outer surface (66) or in the thickness of one of said walls (36), intended to be placed on the side opposite the element to be cooled, preferably on the inner surface of this wall (36).

5. Cooling device (30) according to any one of claims 1 to 4, wherein the cooling device (30) comprises a plurality of active thermoregulation elements (60) configured to operate independently of each other.

6. Cooling device (30) according to claim 5, wherein the active thermoregulation elements (60) are distributed along at least one fluid circulation conduit (52).

7. Cooling device (30) according to any one of claims 1 to 6, wherein the cooling device (30) further comprises at least one sensor (70) configured to measure a property of the heat transfer fluid and / or of an environment of the cooling device (30).

8. Device according to claim 7, wherein at least one sensor (70) is disposed on the internal surface (64), the external surface (66) or in the thickness of at least one wall (36).

9. Cooling device (30) according to claim 7 or 8, wherein at least one sensor (70) comprises at least one temperature sensor and / or at least one humidity sensor, preferably disposed on the external surface (66) of at least one wall (36).

10. Cooling device (30) according to any one of claims 7 to 9, wherein the cooling device (30) comprises at least two flexible walls (36) delimiting at least one conduit (52), at least one sensor (70) comprising at least one temperature sensor disposed on one of said walls (36), intended to be placed on the side of the envelope (32) opposite the elements to be cooled, preferably on an internal surface of this wall (36).

11. Cooling device (30) according to any one of claims 7 to 10, wherein at least one sensor (70) comprises at least one hydrostatic pressure sensor and / or at least one viscosity measurement sensor, preferably disposed on the internal surface (64) of at least one wall (36), so as to be in contact with the fluid.

12. Cooling device (30) according to any one of the preceding claims, wherein the cooling device (30) comprises at least one conductive track (62, 72) extending over the inner surface (64), the outer surface (66) or in the thickness of at least one wall (36), said at least one conductive track (62, 72) being configured to connect the at least one active thermoregulation element (60) and, where applicable, the at least one sensor (70), to a remote control unit.

13. Electric battery (10) comprising: - a plurality of battery cells (14) arranged in an enclosure (12), each battery cell (14) having cooling elements arranged on an upper (18), lower (20), or lateral face of the battery cell (14), and - a cooling device (30) according to one of the preceding claims, at least one wall (36) being arranged to come into contact with the elements to be cooled when the heat transfer fluid circulates in at least one conduit (52).

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