FR2967246A1 - HEAT EXCHANGER FOR ELECTRIC ENERGY STORAGE DEVICE - Google Patents

Abstract

The invention relates to a heat exchanger 1 for the thermal conditioning of an electrical storage device, comprising at least one subassembly consisting of a multiplicity of tubes 4, 5, 19, 20 each delimiting at least one circulation duct a fluid, said tubes 4, 5, 19, 20 extend in the same plane and are connected to each other by a connecting device 24, 25, the conduits of each tube being put in communication by a manifold 26 sealingly attached to the connecting device 24, 25. Application to motor vehicles.

Description

Ref Valeo TFR0839 1 HEAT EXCHANGER FOR ELECTRICAL ENERGY STORAGE DEVICE

The technical sector of the present invention is that of heat exchangers, for example used in the automotive field. The scarcity of oil resources is driving car manufacturers to develop vehicles that operate from new sources of energy. The propulsion of the vehicle by electrical energy is a solution that represents an interesting alternative and it is then necessary to load batteries to store this electrical energy and provide it to an electric motor that propels the vehicle. As a source of electrical energy, as preferably provided by the present invention, efficient batteries with individual NimH or Li-ion elements are used. These prefabricated elements are grouped and connected in series to form a pack of elements or battery pack that results from many individual battery cells with a typical voltage of 3.6 Volts. For these drive battery packs, the individual battery cells are grouped in a common housing to form a high-voltage battery (typical voltages of 130 volts for so-called hybrid vehicles and 360 volts for an animated vehicle exclusively by an electric motor). The battery cells should not exceed their maximum temperature, ranging from 55 to 80 ° C, as this helps to reduce the service life of the elements. Furthermore, the individual elements are electrically connected in series and a defective individual element may be such as to cause a total failure of the battery pack. This is why it is necessary to ensure that the temperature between the individual elements remains homogeneous, that is to say a maximum temperature difference of ± 2 to 5 ° C, preferably ± 2 to 3 ° C. Reflections have already been made to maintain the battery pack at a constant temperature by means of an active fluid cooling system.

Ref Valeo TFR0839 2 However, these considerations do not take into account the dimensional differences that exist between the battery packs used on vehicles of different ranges. These considerations also do not take into account the industrial constraints, in particular the standardization of components called to support the batteries of the pack. The disadvantage of this situation lies in the fact that it is necessary to design, develop and industrialize different technical solutions for each model of vehicle, which increases the costs by absence 1 o mass effect. The invention proposes a new arrangement of a heat exchanger for the thermal conditioning of an electrical energy storage device that provides a solution to these difficulties. The object of the present invention is therefore to solve the disadvantages described above mainly by proposing a new arrangement of a heat exchanger capable of supporting a device for storing electrical energy and whose components can be adapted simply or reused. identically for battery packs of different sizes. The subject of the invention is therefore a heat exchanger for the thermal conditioning of an electrical energy storage device, comprising at least one subassembly consisting of a multiplicity of tubes each delimiting at least one circulation duct. a fluid, said tubes extend in the same plane and are connected to each other by a plurality of connecting devices having identical dimensional characteristics, the conduits of each tube being put in communication by at least one slip box sealingly attached to at least one of the connecting devices. Note that the connecting device connects the tubes only at their ends. It will also be noted that the tubes of the invention are flat tubes, one of the flat faces of these tubes being able to receive or support at least one battery of the electrical energy storage device. A flat tube is a tube that has two opposite and parallel straight walls. This tube is particularly extruded. According to an alternative embodiment, such a tube is obtained by winding or bending an aluminum plate to form a tube whose wall is folded to form the duct or channel. Advantageously, an inner spacer is inserted into the conduit or channel. According to a first characteristic of the invention, the tubes each have a flat outer face which defines said plane. According to a second characteristic of the invention, the connecting device is in the form of a plate, for example a plate, which extends in a plane parallel to said plane of the tubes and gives mechanical support between said tubes, as well as a gap between these. The spacing envisaged here is a space which extends in the plane of the tubes and between them. According to another characteristic of the invention, each tube is connected to the connecting device by a collector, the latter being in particular threaded on the end of a tube. According to another characteristic of the invention, the collector is formed by two hulls joined together to the right of a joint plane, these two shells delimiting a receiving zone secured to the tube and a chamber of fluid distribution. At least one of the shells comprises a hole for placing the distribution chamber in communication with the collecting box. According to yet another characteristic of the invention, the connecting device comprises at least one orifice which puts the distribution chamber in communication with the collecting box. Advantageously, the collectors of the same subset have identical dimensional characteristics. In other words, the collectors 25 of the same subset come from the same tool, and possibly from the same material. Advantageously, the tubes of the same subset have identical dimensional characteristics. In other words, the tubes of the same subassembly come from the same tool or manufacturing process, and possibly from the same material. Advantageously, the connecting devices of the same subset have identical dimensional characteristics. In other words, the connecting devices of the same subset are derived from the same tool or Ref manufacturing process, and possibly the same material. According to another embodiment, the connecting device makes it possible to connect both the tubes of a subset of tubes but also the tubes of at least one other subassembly.

It is also envisaged a variant in which the connecting device makes it possible to connect together each of the tubes of the heat exchanger. According to an alternative embodiment, the heat exchanger comprises a plurality of subassemblies. According to a first aspect of the invention, the dimensional characteristics of the collector boxes of each subset are identical. In other words, the collector boxes of at least two constituent subsets of the exchanger are from the same tool, and possibly the same material. According to a second aspect of the invention, the dimensional characteristics of at least one tube of each subassembly are identical.

According to another aspect of the invention, the dimensional characteristics of at least one collector of each subset are identical. In other words, the collectors of at least two constituent subsets of the exchanger are from the same tool, and possibly the same material. According to yet another aspect of the invention, the dimensional characteristics of at least one connecting device of each subset are identical. In other words, the connecting devices of at least two constituent subsets of the exchanger are from the same tool, and possibly the same material. According to a variant of the invention, the same connecting device connects the plurality of subassemblies. It thus forms a single flat integral with all the constituent tubes of the exchanger according to the invention. According to an alternative to this variant, the exchanger comprises a plurality of connecting device and the dimensional characteristics of at least one connecting device of each subassembly are identical.

The dimensional characteristics mentioned above are: the length, the width, possibly the thickness and / or the height of the component considered. Advantageously, the channels of a duct delimited by a tube are placed in communication by a distribution chamber of the collector, in particular formed by a pair of shells assembled to manufacture the collector. Finally, the invention covers an electrical energy storage device comprising at least one battery, one side of which is in contact with said tubes of the exchanger designed according to one of the characteristics mentioned above.

A first advantage of the invention lies in an ease of design and production of an exchanger for thermally conditioning a set of batteries close together to form a pack. Another advantage lies in the possibility of using an identical tube for all models of exchanger, for example an extruded tube, of which only the length is adapted to the size of the battery pack. Another significant advantage lies in the ability to standardize a length of tube and adapt the width of the exchanger by adding tubes or subassemblies. Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below as an indication in relation to drawings in which: FIG. 1 is a schematic view of a storage device of electric energy according to the invention, - Figure 2 is an exploded view of the end of a tube and its associated collector, - Figure 3 is a perspective view of a shell constituting the collector of the figure 2, - Figure 4 is a partial perspective view of a first end of an exchanger according to the invention, - Figure 5 is a partial perspective view of the components using the heat exchanger of Figure 4 FIG. 6 is a partial perspective view of the other end of the exchanger of FIG. 4, and FIG. 7 is a perspective view of the components implementing the variant of the heat exchanger of FIG. figure 6. It should be noted that the figures disclose the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate.

Ref. 1 Valeo TFR0839 FIG. 1 illustrates an electrical energy storage device 2 comprising a plurality of batteries and a heat exchanger 1 intended to ensure the thermal conditioning of the batteries. This thermal conditioning is understood as a cooling of the batteries but it can also be a heating of the latter, the objective being to maintain this set of batteries at a temperature as homogeneous as possible. The plurality of batteries has a face 3 which is in contact or resting on or against the heat exchanger 1. When the set of batteries is mounted on a vehicle, it is understood that the face 3 is the underside of each of the batteries. In other words, the latter are placed on the exchanger 1, the latter being dimensioned to mechanically support the weight of the batteries. The heat exchanger 1 comprises at least one subassembly which consists of two tubes 4 and 5, at least one connecting device and at least one manifold (the latter two components being visible in Figure 5).

This heat exchanger 1 is supplied with fluid via an intake tube 6, this fluid being able to exit the heat exchanger by means of an evacuation or discharge tube 7. As a For example, it will be noted that this fluid is a heat-transfer fluid such as water added with glycol. In this case, the exchanger according to the invention is part of a heating circuit and / or cooling that equips the motor vehicle. The fluid may also be for example a refrigerant such as a fluorinated compound, especially R134a, or carbon dioxide known under the name R744. The battery pack forms a rectangular pack. The tubes 4 and 5 extend along an axis parallel to the length of the set of batteries.

Each tube 4 and 5 protrudes from the battery assembly and the ends of these tubes receive a collector 8 whose function is to ensure the distribution or collection of the fluid flowing in or to the tubes 4 or 5. The the assembly constituting the exchanger according to the invention comprises in particular at least two fluid transport tubes, which will be called ci-ao after first tube 4 and second tube 5. These two tubes delimit by their outer walls a circulation duct of fluid. These tubes 4 and 5 are flat and extend in the same plane. In this respect, it is understood that the length and width of each of these tubes is significantly greater than the thickness of this tube. In other words, the fluid passage section inside the tube takes a rectangular shape, the large dimension of this rectangle corresponding to the width of the tube. These two flat tubes 4 and 5 are each delimited by at least one outer wall which has a surface or flat face extending in the same plane of that of the immediately adjacent tube. It is understood here that the second tube 5 is aligned in the extension of the first tube 4 so that the plane passing through the outer face of the first tube 4 coincides with the plane passing through the outer face of the second tube 5. The Figure 2 shows exploded the first tube 4 and the collector 8 aligned on the same plane and ready to be threaded on one another. The tube 4 comprises the wall 9 which delimits vis-à-vis the outside an internal volume or fluid circulation duct 10. This internal volume is partitioned by a multiplicity of internal walls 11 thus delimiting several channels 12 in which circulates the fluid. Tube 4 or 5 is an extruded multichannel tube whose material and dimensions are chosen to support the weight of the battery pack. For example, this extruded tube is made from aluminum or aluminum alloy. The dimensions of these tubes are in particular: length 700mm, width 55.5mm, height measured between the outer faces of the tube: 2mm and 0.3mm wall thickness. Advantageously, the conduit is partitioned to delimit 20 channels and the thickness of the internal partitions is for example 0.25mm. The number of tubes, the thickness of the outer walls, the number of channels and internal partitions and their thickness are sized to support the weight of the battery. The values given above are for illustrative purposes. These dimensions may form ranges of values within +/- 20% of the fixed values specified above. The free end of the first tube 4 receives the collector 8. The latter forms a nozzle which ensures a fluid connection between the fluid circulation duct and the other components of the exchanger according to the invention. This manifold 8 is made from two shells referenced 13 and 14. These two shells 13 and 14 have a curved or concave central wall and are assembled one on the other by a joint plane 15. The latter takes the form Ref Valeo TFR0839 8 a flat edge formed at the periphery of the central wall of each of the shells 13 and 14. Once assembled, these two shells 13 and 14 delimit a receiving zone 16 which has a shape complementary to the shape of the end of the tube 4. A sealed assembly is then provided by inserting and welding the end of the tube 4 in the receiving zone 16, in particular by a soldering operation. These two shells 13 and 14 further define a distribution chamber 17 of the fluid. This chamber is produced by a deformation made in the wall of each shell 13 and 14. It will be noted that the depth of this deformation is greater than that practiced at the receiving zone 16. Thus, the volume of the distribution chamber 17 is more important than the volume allocated to the receiving zone 16, so that the pressure drops at the collector 8 are reduced and that the distribution of the fluid is carried out homogeneously in each of the channels.

The structure of each shell 13 and 14 mentioned above is identical. In contrast, one of the shells, here the first shell 13, comprises a through hole 18 formed in its wall at the distribution chamber 17. This hole allows the flow of fluid from the distribution chamber 17 or in direction of the latter. This hole 18 thus makes in fluid communication the distribution chamber 17 of the collector 8 is with one of the intake or discharge tubes 6 or 7, or with a manifold that will be discussed in detail in Figure 5. Figure 3 shows the second shell 14 of dimensions and identical structure to the first shell 13, the only difference residing in the absence of hole. These two shells are advantageously formed by stamping, particularly deep, and made using the same tool. It can be seen from this figure that the joint plane 15 borders one half of the reception zone 16 as well as one half of the distribution chamber 17. The other halves of the reception zone 16 and of the distribution chamber 17 are delimited. by the first shell 13. Figure 4 shows a heat exchanger 1 comprising, in this embodiment, two subassemblies as presented above. The first subassembly comprises the first tube 4 and the second tube Ref Valeo TFR0839 9 5. The free end of each of these two tubes is covered by the collector 8. The receiving zone 16 of the collector 8 is of substantially complementary shape at the free end of a tube, that is to say a rectangular section with rounded edges.

The second subassembly comprises a third tube 19 and a fourth tube 20 whose structure is identical to that of the first and second tubes 4 and 5. The free end of the third and fourth tubes 19 and 20 also comprises a collector 8 of identical to the collectors used in the first subset. At this stage, it is understood that all the tubes referenced 4, 5, 19 and 20 are identical, that is to say of identical dimensions and made from the same material. In the case of an extruded tube, it is thus easy to cut corresponding lengths of tubes corresponding to the need of the exchanger from the same bar or roller forming the extruded raw material. The collectors 8 are also of identical dimensions and of identical structure, which facilitates the logistical management of the manufacture of the heat exchanger 1. The circulation of the fluid of the exchanger shown in FIG. 4 is illustrated by arrows 21 to 23 The manifold on the left in Fig. 4 receives the fluid through the inlet tube. The fluid then spreads in the distribution chamber 17 and then flows in the channels constituting the flow conduit in a first direction. The fluid returns via the circulation duct of the second tube 5 in a direction of flow opposite to the direction of flow in the duct of the first tube 4.

The conduit of the second tube 5 is then placed in communication with a circulation duct of the third tube 19 by means of a manifold. The fluid then flows in the duct of the third tube 19 in a direction opposite to the direction of flow in the duct of the second tube 5. The circulation duct of the third tube 19 is placed in communication with the circulation duct of the fourth tube 20 by means of a collection box. The fluid flowing in the fourth tube 20 is then collected by the manifold 8 to be discharged through the discharge tube. Note that the admission and discharge of the fluid is operated on the same Ref Valeo TFR0839 10 side of the exchanger 1. Figure 5 illustrates the technical means for mechanically maintaining the tubes relative to each other and the means techniques for circulating the fluid from one tube to another.

The tubes 4, 5, 19 and 20 are flat and aligned in the same plane. This alignment is achieved by means of at least two connecting devices 24 and 25. In this exemplary embodiment of the exchanger 1 according to the invention, the alignment is achieved by means of four connecting devices distributed two-to-one. two at each end of the exchanger.

Each connecting device provides a mechanical link between two adjacent tubes, ensuring the alignment in the same plane of the latter and a spacing, for example a few millimeters between two tubes connected by the connecting device. The connecting device 24 or 25 is formed by a flat metal element which can advantageously be welded to the collectors 8. This connecting device has at least one face which extends in a plane parallel to the plane of the tubes that it connects. The material, in particular an aluminum or an aluminum alloy, and the dimensions of the connecting device 24 constituting the first subassembly confer the mechanical maintenance between the tubes 4 and 5. The length of this connecting device, measured in one direction perpendicular to the length of the tubes, is between 110mm and 150mm, a value of 135mm particularly suitable for the intended application of the exchanger. The width, measured in a direction parallel to the length of the tubes, is between 15mm to 30mm, a value of 20mm suitable for application. The thickness of the plate forming for example the connecting device, measured in a direction perpendicular to the plane in which the face of the tube extends, is between 0.5 mm to 2 mm, a value of 1 mm which is well suited to the application thermal conditioning of a device for storing electrical energy produced by the exchanger. The connecting device further comprises two identical orifices 27. This is a hole formed through the connecting device which extends along an axis perpendicular to the plane of extension of the tubes 4 or 5, or the face of the device Ref Valeo TFR0839 11 link 24. This orifice 27 allows the fluid to flow between the collector 8 and the manifold connected to the connecting device. These two orifices, when aligned with the holes of the collectors 8, also guarantee the gap or space that remains between the tubes when the connecting device is secured to the collectors. The variant of Figure 5 shows a connecting device 24 of the first subset separate and distinct from a connecting device 25 of the second subset. According to an alternative, this connecting device can also ensure the mechanical link and the gap between each subset. In such a case, the connecting device is a flat or flat bar which connects each manifold 8 present at one end of the exchanger 1. The fluid flows from the first subassembly to the second subassembly by means of the manifold 26. An identical manifold can also provide communication between two adjacent tubes of the same subassembly. The manifold 26 is sealingly mounted on at least one connecting device 24 or 25. In the case of Figure 5, the manifold 26 is mounted astride the two connecting devices 24 and 25 adjacent. The sealed assembly is provided by welding, in particular brazing, gluing or by the installation of a seal (not shown) between the connecting device 24 and the manifold 26. The manifold 26 has a rectangular flat section 28 which extends in a plane parallel to the extension plane of the connecting device 24.

This flat section 28 has in its center a deformation 29 formed for example by stamping. This deformation 29 is made in a length of the manifold to form a recess, which is particularly oblong. The deformation 29 forms the zone in which the fluid flows from one orifice 27 to the other, either of the same connecting device or of two adjacent connecting devices. Figures 4 and 5 show the organization of the components at a first end of a heat exchanger comprising four tubes. Figures 6 and 7 show Ref Valeo TFR0839 12 the organization of identical components installed at a second end of the same exchanger. FIG. 6 illustrates the circulation of the fluid between the tubes of the same subassembly, by means of arrows referenced 30.

The collector on the left in FIG. 6 receives the fluid coming from the duct delimited by the wall of the first tube 4. The fluid then spreads in the distribution chamber 17 and is then sent to the collector 8 of the second tube 5 situated immediately at the side. The fluid returns via the circulation duct of the second tube 5 in a direction of flow opposite to the direction of flow in the duct of the first tube 4. The duct of the second tube 5 is then placed in communication with the circulation duct of the third tube 19 by means of the manifold as shown in Figure 5. The fluid then flows in the conduit of the third tube 19 in a direction opposite to the direction of flow in the conduit of the second tube 5. The circulation conduit of the third tube 19 is then placed in communication with the circulation duct of the fourth tube 20 by means of a manifold. The fluid flowing in the fourth tube 20 is then collected by the manifold 8 to be discharged through the discharge tube.

Figure 7 shows two manifolds 31 and 32 and two connecting devices used for the implementation of the circulation mentioned in Figure 6. The manifolds referenced 31 and 32 are identical structures. In particular, their dimensions are identical and they are made from the same tool. The heat exchanger as illustrated in the figures defines a circulation of the fluid along a path substantially in W, with an inlet and a discharge which take place respectively on each of the lateral sides of the exchanger.

According to an embodiment not shown, one of the manifolds comprises a through hole to ensure a fluid connection with an intake duct. This hole is preferably made on the top of the manifold, in particular through the wall delimiting the deformation 29. It advantageously allows to feed two adjacent tubes and consequently to be able to propose different circulations, for example example a circulation following a double U-shaped path, with a central inlet and two lateral discharges opening on the side edges of the heat exchanger.

As in FIG. 5, each connecting device 24 and 25 provides a mechanical link between two tubes of the same subassembly. The first manifold 31 covers the first connecting device 24 and the deformation 29 ensures the fluidic communication of the collectors 8 of adjacent tubes after passing through the orifices 27 made through the connecting device.

The flat section 28 is pressed against the face of the connecting device 24 in order to guarantee a liquid seal circulating in the deformation 29. The second manifold 32 has an identical structure and its implantation relative to the other components is identical to that of the first manifold 31.

A heat exchanger 1 as shown in FIGS. 4 to 7 thus comprises: four tubes 4, 5, 19 and 20 which have identical dimensional characteristics, eight collectors 8 which have identical dimensional characteristics, four connecting devices , Which have identical dimensional characteristics, and - three manifolds which have identical dimensional characteristics.

The invention thus makes it possible to constitute a heat exchanger adapted to the thermal conditioning of at least one battery supplying an electric motor which drives the movement of a vehicle by means of only four different types of components, which makes it possible to optimize the manufacturing and logistic management of these components, while ensuring the structural maintenance of the batteries supported by the heat exchanger 1.

Claims (17)

REVENDICATIONS1. Heat exchanger (1) for the thermal conditioning of an electrical energy storage device, comprising at least one subassembly consisting of a multiplicity of tubes (4, 5, 19, 20) each delimiting at least one duct fluid flow, said tubes (4, 5, 19, 20) extend in the same plane and are connected to each other by a plurality of connecting devices (24, 25) having characteristics identical dimensions, the ducts of each tube being placed in communication by at least one manifold (26, 31, 32) sealingly attached to a connecting device (24, 25). 2. Exchanger according to claim 1, wherein the tubes (4, 5, 19, 20) each have a flat outer face which defines said plane. 3. Exchanger according to one of claims 1 or 2, wherein the connecting device (24, 25) is in the form of a plate which extends in a plane parallel to said plane of the tubes (4, 5, 19). , 20) and provides mechanical support between said tubes. 4. Exchanger according to one of claims 1 to 3, wherein each tube (4, 5, 19, 20) is connected to the connecting device (24, 25) by a collector (8). 5. Exchanger according to claim 4, wherein the collector (8) is formed by two shells (13, 14) assembled to each other in line with a joint plane (15), these two shells (13). , 14) delimiting a reception zone (16) secured to the tube (4, 5, 19, 20) and a distribution chamber (17) of the fluid. 6. Exchanger according to claim 5, wherein at least one of the shells (13, 14) comprises a hole (18) for placing the distribution chamber (17) in communication with the header (26, 31, 32). 7. Exchanger according to claim 5 to 6, wherein the connecting device (24, 25) comprises at least one orifice (27) which puts the distribution chamber (17) in communication with the collecting box (26, 31, 32). ). 8. Exchanger according to any one of claims 4 to 7, wherein the collectors (8) of the same subset have identical dimensional characteristics. 9. Exchanger according to any one of the preceding claims, wherein the tubes (4, 5, 19, 20) of the same subassembly have equal dimensional characteristics Raef Valeo TFR0839. 10. Exchanger according to any one of the preceding claims, comprising a plurality of subassemblies. 11. Exchanger according to claim 10, wherein the dimensional characteristics of the manifolds (26, 31, 32) of each subassembly are identical. 12. Exchanger according to any one of claims 10 or 11, wherein the dimensional characteristics of at least one tube (4, 5, 19, 20) of each subassembly are identical. An exchanger according to any one of claims 10 or 12 in combination with any one of claims 4 to 8, wherein the dimensional characteristics of at least one manifold (8) of each subassembly are identical. 14. Exchanger according to any one of claims 10 to 13, wherein a same connecting device (24, 25) connects the plurality of subassemblies. 15. Exchanger according to any one of claims 10 to 13, wherein the dimensional characteristics of at least one connecting device (24, 26) of each subset are identical. 16. Exchanger according to any one of the preceding claims, wherein the channels (11) of a conduit (10) of a tube (4, 5, 19, 20) are placed in communication by a distribution chamber (17). ) of the collector (8). 17. Device (2) for storing electrical energy comprising at least one battery, one side of which is in contact with said tubes (4, 5, 19, 20) of the heat exchanger (1) according to any one of Claims 1 to 16.25