FR3074281A1 - THERMAL DEVICE WITH STORAGE CAPACITY FOR VEHICLE - Google Patents

Abstract

The invention relates to a thermal device with storage capacity (1) for a vehicle intended for the circulation of at least one fluid, comprising an enclosure (5) at least partly delimited by a peripheral wall (6), the enclosure ( 5) housing at least one tube (3) containing a phase change material (21) and delimited by an outer wall (15), a first longitudinal end (13) and a second longitudinal end (18), the enclosure ( 5) comprising a space (17) delimited by the outer wall (15) of the tube (3) and the peripheral wall (6) which delimits the enclosure (5), characterized in that the tube (3) comprises an inner wall (14) delimiting with the outer wall (15) a receiving space (20) containing the phase change material (21), the inner wall (14) defining an inner space (16) to the tube (3), the internal space (16) being open at the first longitudinal end (13) of the tube (3) on the chamber receiver (10) and open at the second longitudinal end (18) of the tube (3) on the collecting chamber (12). Application to motor vehicles.

Description

The field of the present invention is that of thermal batteries and more precisely thermal batteries comprising a phase change material. Thermal batteries allow heat to be stored and returned. They are used for electric, thermal and hybrid vehicles.

When using a thermal storage battery with an electric vehicle, the thermal battery is, in principle, charged when the electric battery of the vehicle is charged. This electric battery is an on-board resource which powers the electric motor (s) during the movement of the vehicle. When using the electric vehicle, the thermal energy stored in the thermal battery can be used when the heating system is started to distribute heat in the passenger compartment of the motor vehicle.

The thermal battery heats the heat transfer fluid before it passes inside an air heater heating the air intended to be diffused in the passenger compartment. The energy supplied by the thermal battery therefore makes it possible to avoid the activation of an electric radiator, thus making it possible to save the corresponding electric energy stored by the electric battery which would have been used in the absence of a thermal battery. storage. Thus, the operation of the heating of the air intended for the passenger compartment via the thermal storage battery does not impact the autonomy of the electric vehicle.

When using a thermal battery with a thermal vehicle, i.e. fitted with an internal combustion engine, the thermal energy stored inside the thermal battery comes from the energy produced during a previous rolling of said vehicle. The fluids used to cool the engine or automatic gearbox, for example, can be used to charge the thermal battery. Indeed, the oil of the automatic gearbox rejects, in conventional use, a determined amount of heat. This determined quantity of heat can be stored in a thermal battery and then used during a subsequent start-up of the motor vehicle, to allow the temperature of the passenger compartment air and / or the oil of the vehicle to increase rapidly. engine and / or automatic transmission oil, reducing friction due to the viscosity of the oil. This reduces overconsumption of fuel at start-up, thereby limiting the emission of pollutants during the first minutes of vehicle use.

In the design of thermal batteries, otherwise known as thermal storage capacity devices, it is already known to use tubes to encapsulate a phase change material capable of storing and releasing a determined quantity of heat. One of the known arrangements of these tubes within the thermal battery is that they are arranged parallel one next to the other to form a bundle, a heat transfer fluid circulating in contact with the wall of the tubes, on their surface, through this beam. These thermal storage capacity devices have several drawbacks.

First, the heat transfer capacities of the phase change material depend on the diameter of the tube that contains it, the phase change material at the heart of the tube being less accessible than that near the surface of the tube, located more directly. at the tube / liquid interface. As a result, the phase change material at the heart of the tube sees its heat transfer capacities reduced compared to the phase change material located closer to the wall of the tube. The heat transfer involving this core, whether for charging or discharging, is made difficult by the greater distance: the phase change material cannot therefore be mobilized in the same way depending on its position in the tube .

Second, the circulation space defined in the thermal batteries of the prior art is a single space, which can only accommodate a single fluid. The charging and discharging of the thermal battery are therefore sequential: the fluid is intended firstly to transfer its calories to the material with phase change, and secondly to retransmit to this same fluid the energy necessary to heat it .

Increasing the heat capacity of thermal batteries and increasing the charge and discharge speed of the phase change material, reflections of its efficiency, are therefore challenges in themselves. Overcoming the sequential aspects of thermal batteries would also be beneficial. The resolution of these problems is all the more appreciated as the solutions provided guarantee the compactness of the thermal battery.

The aim of the present invention is therefore to solve the drawbacks described above by designing a thermal device with storage capacity, where the circulating heat transfer fluid is distributed in a homogeneous manner, and where the heat storage, and therefore the heat transfer power, is increased.

The subject of the invention is therefore a thermal device with storage capacity for a vehicle intended for the circulation of at least one fluid, comprising an enclosure at least partially delimited by a peripheral wall, the enclosure comprising at least one opening for fluid inlet formed in the enclosure and leading to a receiving chamber delimited by the enclosure and a fluid outlet opening formed in the enclosure and opening out to a collecting chamber delimited by the enclosure, the enclosure housing at least one tube containing a phase change material and delimited by an external wall, a first longitudinal end and a second longitudinal end, the enclosure comprising a space delimited by the external wall of the tube and the peripheral wall which delimits the enclosure, characterized in that the tube includes an internal wall defining with the external wall a receiving space containing the phase change material, the internal wall further delimiting a space internal to the tube, the internal space being open at the first longitudinal end of the tube on the receiving chamber and open at the second longitudinal end of the tube on the collector chamber.

The enclosure, which delimits the edges of the thermal device with storage capacity, comprises a cylindrical wall, the longitudinal ends of which are closed off by a cover fitting at the level of the cylindrical wall.

Within this enclosure, various compartments are identified, each capable of seeing a fluid circulate. The fluid or fluids put into circulation are so-called heat transfer fluids, capable of carrying calories, transferring these calories to the phase change material or recovering them, depending on the energy state of the fluid in question. Mention may be made, by way of nonlimiting example, of heat transfer fluids such as gearbox oil, engine oil, engine coolant.

The first advantage of the storage capacity thermal device according to the invention lies in the increase in the specific exchange surface of the tube. Indeed, the tube, made hollow by an internal space, sees its surface increase. To the external wall of the tube is added the internal wall of the tube, both in contact with a single or several fluids surrounding and / or passing through the tube. Two wall / phase change material interfaces are thus present for a single tube. Thanks to a larger surface, the tube increases its heat exchange capacities.

The inner wall and the outer wall of the same tube or tubes are cylindrical and concentric. Due to the cylindrical shape of the inner wall, the receiving space is also cylindrical. According to a measurement taken radially with respect to an axis of elongation of the tube, the receiving space, taking the form of a ring, seen in cross section with respect to this same axis, has a thickness of 1 to 4 millimeters.

The annular distribution of the phase change material promotes the charge / discharge speed of the device object of the invention. Indeed, the core of the phase change material is displaced relative to the configuration of the solid tube, promoting better accessibility to the energy stored in the center of the phase change material. The core of the phase change material corresponds to a ring equidistant from the two walls of the hollow tube.

The receiving space is closed at the longitudinal ends of the tube, by welding the external and internal walls using the same material as that of the walls, or by a rivet or by crimping. These closing techniques nevertheless leave an opening for the circulation of the fluid in the tube. The longitudinal ends of the tube can also be closed by attached plugs, also forming spacers between the inner wall and the outer wall. This plug has a central opening opening. Thus, the phase change material remains contained in the reception space, not mixing with the circulating fluid (s).

The phase change material can be chosen from the group consisting of a fatty acid of vegetable origin, a fatty alcohol of vegetable origin, a paraffin, a hydrated salt and their mixtures. The phase change material may have a phase change temperature between 45 and 100 ° C. The phase change material may have a latent heat of phase change greater than 200 kJ / kg, and preferably greater than 280 kJ / kg. Latent heat of phase change guarantees a great capacity to store energy.

The tubes can take different forms individually, and organize themselves in different ways: these tubes can be straight or curved. Their curvature can be more or less pronounced, until the tube takes the form of a winding. The storage capacity thermal device may contain only a single coiled tube.

These same tubes, straight or curved, can be grouped into a network, a network resulting from the assembly of a plurality of tubes. This network can for example form a single bundle of tubes, or a plurality of bundles, the tubes being parallel to each other within the same bundle. The organization in bundle finds its advantage during the assembly of the thermal device with storage capacity. The beam organization also induces a short circuit through the internal space of the tubes. Within a single beam, it should be noted that the internal spaces of the tubes sharing this beam can be collinear.

Alternatives of the invention will now be described, configured by the circuit or circuits and the compartments defining them, intended to see the circulation of one or more fluids.

The hollow tube allows the coexistence of two fluid circulation circuits isolated from each other by the receiving space. Thus, a tube makes it possible to distinguish two spaces, the reception space serving as partitioning. This compartmentalisation does not however exclude the possibility of a thermal device with storage capacity according to the invention of being provided with a single fluid circulation circuit, where the same fluid would come indistinctly in contact with one or the other. other wall of the tube.

This is how the fluid in contact with the external wall of the tube can be of the same or different nature as the fluid in contact with the internal wall. In the case of two fluids of the same kind, these fluids can be part of the same circuit or of different circuits. These fluids can be subjected to different states, for example their viscosity and / or their temperature.

Thus, according to one aspect of the invention, the enclosure contains at least two separate circuits, separated by at least one partition wall, a first circuit comprising the peripheral space and a second circuit comprising the receiving chamber, the internal space to the tubes and the collecting chamber.

The thermal device with storage capacity is partitioned in order to accommodate a plurality of fluids. The partitioning into two circuits, each capable of seeing a fluid circulate independently, is done via the partition wall. In order to separate the second circuit from the peripheral space constituting the first circuit, this wall can be attached to the longitudinal ends of the tubes, without closing off the internal space. This partition wall is sealed and secured to the external wall of at least one tube, or tubes in the case of a bundle of tubes. The partition wall can then take the form of a plate provided with open passages each on an internal space of a tube. Thus, each wall of the tube participates in the delimitation of one of the circuits: the external wall of the tube for the first circuit, the internal wall of the tube for the second circuit.

Because of this partitioning, the fluid inlet opening, opening onto the receiving chamber delimited by the enclosure, and the fluid outlet opening, opening out into the collecting chamber delimited by the enclosure, are both clean on the second circuit. Furthermore, a first fluid inlet mouth and a second fluid outlet mouth are provided in the enclosure, at the peripheral wall delimiting the peripheral space.

The existence of two circuits makes it possible to circulate a fluid of different nature or a fluid of the same nature but with different thermal characteristics in each of the circuits. By this configuration, two different fluids can benefit simultaneously from the discharge of thermal energy supplied by the phase change material. Likewise, these two fluids can transmit their calories to the phase change material at the same time. Furthermore, the phase change material can be loaded with thermal energy for one time by one of the fluids, and in a second time restore this energy, to the fluid by which the phase change material has been loaded or other fluid.

According to an alternative aspect of the invention, the enclosure contains a single circuit, comprising the receiving chamber, the space internal to the tubes, the peripheral space and the collecting chamber. The enclosure is then not provided with a partition wall. For this alternative, all the compartments of the thermal device are connected directly or indirectly, with the exception of the space for receiving the tubes. A single fluid is then caused to circulate in the thermal device with storage capacity according to the invention.

For a single circulating fluid, this fluid can charge its thermal energy towards the phase change material; at a later time, this energy will be returned to it, the charge and discharge cycles alternating. By the presence of the internal space in the hollow tube, this unique fluid will circulate both inside and outside the tube, benefiting from a larger heat transfer surface than if the tube was full. This increases the heat transfer power.

According to another aspect of the invention, a partition wall imposes a circulation of the fluid in a "U" shape inside the enclosure. This partition wall makes it possible to subdivide the peripheral space, forcing the circulation of the fluid in a part of the peripheral space, then in another part. The circulation in "U" is directly linked to the position of the openings and, if they are present, of the vents. The partition wall shaping the "U" aims to increase the heat exchange time since the path between two openings is longer. Due to the presence of a partition wall, the circulation of the fluid in the same compartment takes place in two different directions, on either side of this "U".

An embodiment of the invention provides for inducing a U-shaped circulation in the first circuit of a thermal device with storage capacity with two circuits. The mouths are then for example carried by the same side of the peripheral wall.

Another embodiment provides for inducing a U-shaped circulation in the circuit tunic. This circuit includes the first inlet opening and the second fluid outlet opening carried on a single enclosure cover, the collecting chamber and the receiving chamber being located side by side in this configuration. The partition wall extends from this cover, separating the collecting chamber from the receiving chamber. The partition wall extends beyond the chambers through part of the peripheral space, so that the partition wall has a free border and forms a "U" shaped space. For a network of tubes parallel to each other, this network is divided into two beams within which the fluid circulates in opposite directions. The fluid then makes two passes, Tune in a first beam in a direction of circulation, the other in a second beam in the opposite direction.

According to another aspect of this embodiment, the thermal device with storage capacity comprises at least one intermediate chamber formed in the enclosure opposite the collecting chamber and the receiving chamber with respect to the tubes. This intermediate chamber provides the transition between two passes in the tubes, for example when the enclosure contains two bundles of tubes. In this case, the fluid passes from the collecting chamber to the intermediate chamber via the two bundles of tubes separated from the intermediate chamber. The intermediate chamber is then located at the end of the first pass, and at the entrance of the second pass.

According to an example of the invention, the first inlet opening and the second fluid outlet opening are opposite each other with respect to the tube. The receiving chamber and the collecting chamber are also located opposite each other in the enclosure with respect to the tube. In this configuration, if the tubes are organized in bundles, the fluid circulates in a mono-directional way from one chamber to another within the thermal device with storage capacity. The heat transfer fluid then performs a single pass.

According to another aspect of the invention, the internal wall and / or the external wall of the tube are made of synthetic material. This synthetic, flexible material allows the walls of the tube to have mechanical resistance properties when the tube expands. The tube can indeed expand in response to the modification of the phase change material contained between the two walls, between its states of charge and discharge. This flexibility is also advantageous for tubes taking a curved or rolled configuration, ensuring flexibility to the assembly, without risk of rupture. Finally, synthetic materials, in addition to being neutral with respect to the phase change material, have the advantage of being light, which makes it possible to minimize the weight of the thermal device with storage capacity. This synthetic material can be a polymer, preferably a polycarbonate, a polyester or a polyamide.

According to an alternative aspect of the invention, the inner wall and the outer wall of the tube are made of a thermally conductive material. A thermally conductive material facilitates heat transfer when charging and discharging the phase change material. More particularly, this thermally conductive material can be a metal or a charged synthetic material. Advantageously, the metal chosen is aluminum or one of its alloys, which has the advantage of combining thermal conductivity with lightness, without altering the properties of the phase change material on contact.

According to another aspect of the invention, the space for receiving the tube houses at least one thermally conductive element. In order to improve the thermal conductivity of the tube and for better transport of calories, the phase change material included in the receiving space a thermally conductive element which can drain these calories.

In particular, the thermally conductive element comprises or takes the form of at least one fin, for example metallic. The orientation of the metal fins favors the transit of thermal energy within the reception space. Alternatively, the thermally conductive element comprises a metallic powder. Alternatively still, the thermally conductive element comprises carbon nanotubes. This metal powder and / or these carbon nanotubes can be distributed in the phase change material.

According to another aspect of the invention, the external wall and the internal wall of the tube are concentric, at least the thermally conductive element connecting the external wall to the internal wall. Thus, the fin makes it possible to guarantee the spacing between the external wall and the internal wall of the tube, in order to guarantee the concentricity of these two walls. In addition to its function of transporting calories, the thermally conductive element, for example the fin, participates in the mechanical maintenance of the external wall relative to the internal wall of the tube.

Several fins, if they are distributed homogeneously in the receiving space, for example by connecting the internal wall to the external wall of the tube, also make it possible to absorb the deformation imposed by the phase change material, expanding and retracting.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description given below by way of indication in relation to the drawings in which:

- Figure 1 is a schematic view of a thermal device with storage capacity according to a first embodiment of the invention,

FIG. 2 is a schematic view of a thermal device with storage capacity according to a second embodiment of the invention,

FIG. 3 is a schematic view of a thermal device with storage capacity according to a third embodiment of the invention,

FIG. 4 is a perspective view of a tube, part of a thermal device with storage capacity according to the invention, according to any one of the embodiments,

- Figure 5 is a sectional view of the tube according to Figure 4.

It should first be noted that the figures show the invention in detail to implement the invention, said figures can of course be used to better define the invention, if necessary.

In the following description, the longitudinal nature of the components will be assessed with respect to an axis called the central axis X of the enclosure, defined by an enclosure specific to the device with storage capacity according to the invention, the central axis X d enclosure extending between one and the other of the longitudinal ends of the enclosure. Will be considered as longitudinal any object or axis extending substantially in the same direction as the central axis X of the enclosure. By transverse, we mean any object or axis coming to cut the central axis X of the enclosure.

A thermal device with storage capacity 1 according to a first embodiment is shown in FIG. 1. This embodiment corresponds to a thermal device with storage capacity 1 having a single circuit 2, this circuit 2 passing right through. share of tubes 3 organized in bundle 4.

The storage capacity thermal device 1 according to FIG. 1 is delimited by an enclosure 5. This enclosure 5 is provided with a peripheral wall 6 closed by a first cover 7 at one of the longitudinal ends of the enclosure 5, and by a second cover 8 at the longitudinal end of the enclosure 5 opposite with respect to the peripheral wall 6. The peripheral wall 6, the first cover 7 and the second cover 8 cooperate hermetically, by interlocking, for example.

The first cover 7 of the enclosure 5 is provided with a fluid inlet opening 9. This fluid inlet opening 9 opens onto a receiving chamber 10. The second cover 8 of the enclosure 5 is provided with a fluid outlet opening 11, opening onto a collecting chamber 12. The openings 9, 11 of fluid inlet and fluid outlet are thus each located at one of the longitudinal ends of the enclosure 5, just like the receiving chamber 10 and the collecting chamber 12.

Between the receiving chamber 10 and the collecting chamber 12 is located the bundle 4 of tubes 3, the tubes 3 being rectilinear and organized parallel to each other within this bundle 4. The tubes 3 are provided with a first end longitudinal 13 and a second longitudinal end 18, respectively with respect to the receiving chamber 10 and the collecting chamber 12. Each of the tubes 3 is made up of two walls, an internal wall 14 and an external wall 15, so that that each tube 3 is hollow. The tube or tubes are thus each provided with an internal space 16 open at the first longitudinal end 13 on the receiving chamber 10, and at the second longitudinal end 18 of the tube 3 on the collecting chamber 12.

The external wall 15 delimits with the peripheral wall 6 of the enclosure 5 a peripheral space 17. This space is peripheral in that it surrounds the external walls of the tubes, being also delimited by the peripheral wall 6. Des grids 19, positioned parallel to the covers 7, 8, keep the bundle 4 in position in the enclosure 5 between the receiving chamber 10 and the peripheral space 17 and between the collecting chamber 12 and the peripheral space 17, without, however, closing off the communication between this peripheral space 17 and the receiving chamber 10 on the one hand, and this peripheral space 17 and the collecting chamber 12 on the other hand.

Between the internal wall 14 and the external wall 15 of the same tube 3 is delimited a receiving space 20 used to encapsulate a phase change material 21, so that the receiving space 20 is not open on the rest of enclosure 5.

We will now describe the circulation of a fluid within the thermal device with storage capacity 1 illustrated in FIG. 1. A single circuit 2 is present in this enclosure 5, and only a fluid represented by the arrows circulates. This fluid describes a generally rectilinear and monodirectional trajectory, parallel to the central axis X of enclosure 5. The circuit 2 comprises the receiving chamber 10, the internal space 16 with the tubes 3, the peripheral space 17 with the tubes 3 and the collecting chamber 12.

The fluid enters through an inlet port 22, used to connect the thermal device with storage capacity 1 to an external loop to the thermal device according to the invention. This inlet port 22 is positioned to the right of the fluid inlet opening 9 located on the first cover 7 of the enclosure 5. The fluid, passing through this inlet port 22 and this opening 9 inlet of fluid, spreads in the receiving chamber 10 which communicates both with the internal space 16 of the tubes 3 of the bundle 4 and with the peripheral space 17 with the tubes 3. Thus, the fluid borrows the internal space 16 and the peripheral space 17, before being collected at the collecting chamber 12. Arrived in this collecting chamber 12, it is directed towards the opening 11 of fluid outlet formed in the second cover 8 of the enclosure 5, before d borrow an output port 23. The latter is arranged opposite the fluid outlet opening 11, and connects the circuit of the thermal device with storage capacity 1 to the external loop to the thermal storage device 1.

During its passage in the peripheral space 17 or the internal space 16, the fluid operates with the tubes 3 a thermal transfer, allowing it to collect or charge calories at the level of the phase change material 21. The latter is charges or discharges more quickly because the fluid is in contact with both the outer wall 15 and the inner wall 14 of the tube 3.

FIG. 2 illustrates a thermal device with storage capacity 1 according to a second embodiment. The latter corresponds to the thermal device with storage capacity 1 with a single circuit 2 illustrated in FIG. 1, and reference will be made to the description of this figure for the common elements.

The circuit 2 crosses right through the tubes 3 organized two beams 4, 24. This circuit 2 is imposed a configuration in "U" due to the presence of a partition wall 25 arranged along the central axis X of pregnant. The two beams 4, 24 are in communication via an intermediate chamber 26 and are located on either side of the partition wall 25.

The thermal storage capacity device 1 according to FIG. 2 is delimited by the enclosure 5. This enclosure 5 is provided with the peripheral wall 6 closed by a cover 7 at one of the longitudinal ends of the enclosure 5, and by a bottom 27 disposed at the longitudinal end of the enclosure 5. The peripheral wall 6 and the bottom 27 cooperate hermetically, for example by welding. Peripheral wall 6 and bottom 27 can also result from deep drawing, thus forming a one-piece casing.

The cover 7 of the enclosure 5 is provided with the fluid inlet opening 9 and the fluid outlet opening 11 opening one onto the receiving chamber 10, the other onto the collecting chamber 12. In this second embodiment, the openings 9, 11 for fluid inlet and outlet for fluid are each situated at the same longitudinal end of the enclosure 5, just like the receiving chamber 10 and the collecting chamber 12.

The receiving chamber 10 and the collecting chamber 12 are separated by a partition wall 25, arranged perpendicularly to the cover 7 of the enclosure 5, in the central axis X of enclosure 5. This partition wall 25 is attached to the cover 7 and extends between the receiving 10 and collecting 12 chambers, so that the receiving chamber 10 and the collecting chamber 12 are not in direct communication. The partition wall 25 extends into the enclosure 5, without however reaching the bottom 27 of the enclosure 5, so that the partition wall 25 has a free border 28 and draws a U-shaped circulation in the pregnant 5.

Two bundles 4, 24 of tubes 3 are similar and located side by side. They are both formed of 3 straight tubes and organized parallel to each other. The partition wall 25, which extends into the enclosure 5, crosses this enclosure 5 over the entire length of the beams 4, 24 which it separates. The tubes 3 are provided with their first longitudinal end 13 and with their second longitudinal end 18. The receiving chamber 10 is disposed between the fluid inlet opening 9 and the first longitudinal end 13 of the tubes 3 of the first bundle 4. The collecting chamber 12 is formed between the fluid outlet opening 11 and the second longitudinal end 18 of the tubes 3 of the second bundle 24. The intermediate chamber 26 is disposed between the bottom 27 of the enclosure 5 and the second end longitudinal 18 of the tubes 3 of the first bundle 4 as well as the first longitudinal end 13 of the tubes 3 of the second bundle 24.

Each of the tubes 3 is made up of two walls, the internal wall 14 and the external wall 15, so that each tube 3 is hollow, that is to say provided with the internal space 16. This internal space 16 is tubes 3 of the first bundle 4 is open on the receiving chamber 10 at their first longitudinal end 13 and on the intermediate chamber 26 at their second longitudinal end 18. This internal space 16 of the tubes 3 of the second bundle 24 is open on the intermediate chamber 26 at their first longitudinal end 13 and on the collecting chamber 12 at their second longitudinal end 18.

The external wall 15 delimits with the peripheral wall 6 of the enclosure 5 the peripheral space 17. The grids 19, positioned parallel to the cover 7, hold the beams 24 in position in the enclosure 5 between the receiving chamber 10 and the intermediate chamber 26 for the first beam 4, and between the intermediate chamber 26 and the collecting chamber 12 for the second beam 24. These grids 19, however, do not block the communication between the peripheral space 17 and the receiving chamber 10 on the one hand, between the peripheral space 17 and the collecting chamber 12 on the other hand and between the intermediate chamber 26 and the peripheral space 17, finally.

The circulation of a fluid within the thermal device with storage capacity 1 illustrated in FIG. 2 will now be described. A single circuit 2 is present in this enclosure 5, and only sees a fluid represented by the arrows. This fluid describes a U-shaped trajectory, due to the presence of the partition wall 25. The circuit 2 comprises the receiving chamber 10, the internal space 16 in the tubes 3 of the first beam 4 and the second beam 24, l peripheral space 17 to the tubes 3 partitioned in a "U" shape, the collecting chamber 12 and the intermediate chamber 26.

The fluid enters through the input port 22, used to connect the thermal device with storage capacity 1 to an external loop to the thermal device. This inlet port 22 is positioned opposite the fluid inlet opening 9 located on the cover 7 of the enclosure 5. The fluid, passing through this inlet port 22 and this fluid inlet opening 9 , is received by the receiving chamber 10 which communicates both with the internal space 16 of the tubes 3 of the first beam 4, and the peripheral space 17 to the tubes 3 of the first beam 4. Thus, the fluid borrows in a first direction circulation the internal space 16 and the peripheral space 17 to the first beam 4, before being received in the intermediate chamber 26. From this intermediate chamber 26, the fluid joins the internal space 16 and the peripheral space 17 to the second beam 24, where it circulates in a second direction of circulation opposite to the first direction of circulation, before being collected in the collecting chamber 12. Arrived in this collecting chamber 12, it is directed towards the opening 11 of fluid outlet formed in the second cover of the enclosure 5 before passing through the outlet port 23.

During its passage in the peripheral space 17 and in the internal space 16 of the tubes 3, the fluid has operated with these tubes a thermal transfer, allowing it to collect or charge thermal energy at the level of the material to be changed. phase 21. In this configuration, the fluid makes two passes since it passes through two bundles 4, 24 of separate tubes 3.

Referring now to Figure 3, a thermal storage device 1 according to a third embodiment is shown. Here, two circuits 29, 30 are differentiated by means of partition walls 31, 32. A first circuit 29, organized in “U” by a partition wall 25, is located on the periphery of tubes 3 organized in a single bundle 4. A second circuit 30 is monodirectional and passes right through the bundle 4 of tubes 3.

The thermal storage capacity device 1 according to FIG. 3 is delimited by the enclosure 5. This enclosure 5 is provided with the peripheral wall 6 closed by the first cover 7 at one of the longitudinal ends of the enclosure 5, and by the second cover 8 at the longitudinal end of the enclosure 5 opposite with respect to the peripheral wall 6, so that the peripheral wall 6, the first cover 7 and the second cover 8 cooperate hermetically.

The first cover 7 of the enclosure 5 is provided with the fluid inlet opening 9. This fluid inlet opening 9 opens onto the receiving chamber 10. The second cover 8 of the enclosure 5 is provided with the fluid outlet opening 11, opening onto the collecting chamber 12. The openings 9, 11 of fluid inlet and fluid outlet are thus each located at one of the longitudinal ends of the enclosure 5, just like the receiving chamber 10 and the collecting chamber 12.

Between the receiving chamber 10 and the collecting chamber 12 is located a single bundle 4 of tubes 3, the tubes 3 being rectilinear and organized parallel to one another within this bundle 4. The tubes 3 are provided with their first end longitudinal 13 and their second longitudinal end 18, respectively with regard to the receiving chamber 10 and the collecting chamber 12. Each of the tubes 3 consists of two walls, the inner wall 14 and the outer wall 15, so that each tube 3 is hollow, provided with the internal space 16 open at the first longitudinal end 13 on the receiving chamber 10, and at the second longitudinal end 18 of the tube 3 on the collecting chamber 12.

The outer wall 15 delimits with the peripheral wall 6 of the enclosure 5 the peripheral space 17. At the level of one and the other of the longitudinal ends 13, 18 of the tubes 3, a first partition wall 31 and a second partition wall 32, positioned parallel to the covers 7, 8, partition the peripheral space 17 of the bundle 4, thus delimiting the first circuit 29. The first partition wall 31 and the second partition wall 32 are each integral longitudinal ends 13, 18 of the tubes 3 in a sealed manner. The tubes 3 are therefore not closed off by these partition walls 31, 32, the partition walls 31, 32 being provided with passages leaving free the internal space 16 of the tubes 3. These passages are of the same diameter as the external walls 15 tubes 3, in order to adjust to it.

The peripheral wall 6 comprises an inlet mouth 33 and an outlet mouth 34, putting this first circuit 29 in communication with the outside of the enclosure 5. The two separation walls 31, 32 hold the beam 4 in position in the enclosure 5 between the receiving chamber 10 and the collecting chamber 12, by closing the communication between this peripheral space 17, constituting the first circuit 29, and the second circuit 30, made of the receiving chamber 10 on the one hand, of the collecting chamber 12 on the other hand, and internal space 16 to the tubes 3 of the bundle 4.

A partition wall 25 further separates the first circuit 29. This partition wall 25 being transversely in the enclosure 5 from the peripheral wall 6, between the vents 33, 34, perpendicular to the central axis X of the enclosure 5, without however closing the enclosure 5. The partition wall 25 is moreover provided with a free border 28 and draws a “U” -shaped space in the first circuit 29. Note that this partition wall 25 is provided with perforations, leaving a passage to the tubes 3 of the bundle which cross the partition wall 25. These perforations are of the same diameter as the tubes 3, in order to fit there in a sealed manner.

The reception space 20 is delimited by the internal wall 14 and the external wall 15 of the tubes 3, and serves to contain the phase change material 21 in a closed manner. The reception space 20 is therefore not open on the rest of enclosure 5.

The circulation of a fluid within the thermal device with storage capacity 1 illustrated in FIG. 3 will now be described. The two circuits 29, 30 are traversed by two fluids distinguished by the arrows, these two fluids possibly being distinct or identical.

The first fluid within the first circuit 29 describes a U-shaped trajectory, imposed by the presence of the partition wall 25. The first circuit 29 comprises the peripheral space 17 to the tubes 3. The first fluid enters this peripheral space 17 via an input port 35 which is used to connect the thermal device with storage capacity 1 to an external loop. The inlet port 35 is connected to the inlet mouth 33, which opens onto the peripheral space 17, facing the second longitudinal ends 18 of the tubes 3 of the bundle 4. Launched in its path through the peripheral space 17 , the first fluid crosses transversely a first part 36 of the peripheral space 17, effecting a change of direction at the level of the space formed between the free edge 28 of the partition wall 25 and the peripheral wall 6 of the enclosure 5 The first fluid then arrives in a second part 37 of the peripheral space 17, joining the mouth 34 of fluid outlet then a fluid outlet port 38, connecting the first circuit 29 of the thermal device with storage capacity 1 to the external loop mentioned above.

The second fluid within the second circuit 30 describes a rectilinear and unidirectional trajectory, parallel to the central axis X of enclosure 5. The second circuit is comparable to the circuit described in relation to FIG. 1. The second circuit 30 comprises the chamber receiver 10, the internal space 16 to the tubes 3 and the collecting chamber 12. The second fluid enters through the inlet port 22. This inlet port 22 is positioned at the level of the fluid inlet opening 9 situated on the first cover 7 of the enclosure 5. The first fluid, passing through this inlet port 22 and this fluid inlet opening 9, is received in the receiving chamber 10 which communicates with the internal space 16 of the tubes 3 of the bundle 4. Thus, the second fluid borrows the internal space 16 from the tubes 3, before being collected at the level of the collecting chamber 12. Arrived in this collecting chamber 12, it is directed towards the opening 11 of outlet d e fluid formed in the second cover 8 of the enclosure 5, before passing through the outlet port 23.

During their passage in the first circuit 29 or the second circuit 30, the fluids operate with the tubes 3 a thermal transfer, allowing them to collect or charge calories from or to the phase change material 21. Several configurations are possible : the two fluids both simultaneously or sequentially transfer their thermal energy to the phase change material 21; the two fluids recover thermal energy simultaneously or sequentially from the phase change material 21; the fluid of the first circuit 29 transfers thermal energy to the phase change material 21, while the fluid of the second circuit 30 subsequently recovers it; the fluid of the second circuit 30 transfers thermal energy to the phase change material 21, while the fluid of the first circuit 29 recovers it later.

Figure 4 shows a tube 3 constituting any of the embodiments described above. The following description applies to one tube or to a plurality of tubes.

The tube 3 is hollow and it is part of the thermal device with storage capacity 1 according to the invention. The tube 3 here takes a rectilinear shape, directed along an elongation axis Y of the tube 3. This tube 3 is closed at its longitudinal ends 13, 18 by a plug 39, 40, which closes the walls 14, 15 of the tube 3, allowing the phase change material to be encapsulated 21. Each plug 39, 40 is provided with an orifice 41, giving access to the internal space 16 of the tube 3, capable of seeing a fluid circulate. The external wall 15 and / or the internal wall 16 of the tube 3 are made, for example, of a synthetic material and / or of a thermal conductive material, such as aluminum or one of its alloys.

FIG. 5 shows the tube 3 seen along the cross section A shown in FIG. 4. The external wall 15 and the internal wall 14 delimit two spaces in the tube 3: the internal space 16 delimited by the internal wall 14 and the reception space 20, delimited by the internal wall 14 and the external wall 15. The internal wall 14 and the external wall 15 are concentric and connected by a thermally conductive element 42 disposed inside the reception space 20. According to an exemplary embodiment, such a thermally conductive element 42 takes the form of one or more fins 43 which extend longitudinally and forming bridges between the inner wall 14 and the outer wall 15. These fins 42 are homogeneously distributed in the reception space 20. They therefore orient themselves in a longitudinal direction parallel to an axis Y of elongation of the tube 3, and radially all around the axis of elongation Y. ux successive fins 43 delimit, alternately with the internal wall 14 or the external wall 15, a space of the triangular shape seen in section, dividing the reception space 20.

The phase change material 21 is distributed in the reception space 20 and it is in contact with each face of one or more fins 43. As these fins 43 are in contact with the internal wall 14 and the external wall 15, they drain calories into the receiving space 20 from or to the internal wall 14 and / or from or to the external wall 15. The fins 42 are for example made of a metallic material, thermal conductor, making it possible to facilitate heat transfers involving the phase change material.

According to another example, the thermally conductive element 42 can also take the form of a metal powder and / or carbon nanotubes distributed in the phase change material. As for the fin 43, this metallic powder and / or these carbon nanotubes make it possible to distribute the calories at the heart of the phase change material.

It will be understood from reading the above that the present invention provides a thermal device with storage capacity for a vehicle configured to allow optimal, rapid thermal transfer, by promoting accessibility to the phase change material housed in the tubes. This accessibility is made possible by hollow tubes which, by providing an internal space, increase the possibilities of interface vis-à-vis circulating fluids not only at the periphery of the tube, but also in the center of this tube. Thanks to these hollow tubes, the thermal device with storage capacity can be compartmentalized in different ways, in order to create a single circuit or a plurality of circuits. This thermal storage device, intended to be integrated in electric vehicles, as well as thermal or hybrid, does not go to the detriment of the compactness of said device, since the hollow tube does not in itself modify the overall volume of the thermal device to storage capacity.

The invention cannot however be limited to the means and configurations described and illustrated here, and it also extends to any equivalent means or configuration and to any technical combination operating such means. In particular, the shape of the thermal device with storage capacity for a vehicle can be modified without harming the invention, insofar as the thermal device with storage capacity for a vehicle, ultimately, fulfills the same functions as those described in this document. .

Claims (10)

1. Thermal device with storage capacity (1) for a vehicle intended for the circulation of at least one fluid, comprising an enclosure (5) at least partially delimited by a peripheral wall (6), the enclosure (5) comprising at least one opening (9) for fluid inlet formed in the enclosure (5) and leading to a receiving chamber (10) delimited by the enclosure (5) and an opening (11) for fluid outlet formed in the enclosure (5) and opening onto a collecting chamber (12) delimited by the enclosure (5), the enclosure (5) housing at least one tube (3) containing a phase change material (21) and delimited by an external wall (15), a first longitudinal end (13) and a second longitudinal end (18), the enclosure (5) comprising a space (17) delimited by the external wall (15) of the tube (3) and the peripheral wall (6) which delimits the enclosure (5), characterized in that the tube (3) comprises a wall internal (14) delimiting with the external wall (15) a receiving space (20) containing the phase change material (21), the internal wall (14) further delimiting an internal space (16) in the tube (3) , the internal space (16) being open at the first longitudinal end (13) of the tube (3) on the receiving chamber (10) and open at the second longitudinal end (18) of the tube (3) on the collecting chamber (12). 2. A thermal storage capacity device (1) according to claim 1, in which the enclosure (5) contains at least two separate circuits (29, 30), separated by at least one partition wall (31, 32), a first circuit (29) comprising the peripheral space (17) and a second circuit (30) comprising the receiving chamber (10), the internal space (16) in the tubes (3) and the collecting chamber (12). 3. thermal device with storage capacity (1) according to claim 1, in which the enclosure (5) contains a single circuit (2), comprising the receiving chamber (10), the internal space (16) in the tubes ( 3), the peripheral space (17) and the collecting chamber (12). 4. A storage capacity thermal device (1) according to any one of the preceding claims, in which a partition wall (25) imposes a circulation of the fluid in a "U" shape inside the enclosure (5). 5. Storage capacity thermal device (1) according to any one of the preceding claims, comprising at least one intermediate chamber (26) formed in the enclosure (5) opposite the collecting chamber (12) and the chamber receiver (10) relative to the tubes (3). 6. Thermal device with storage capacity (1) according to any one of the preceding claims, in which the internal wall (14) and / or the external wall (15) of the tube (3) are made of synthetic material. 7. A storage capacity thermal device (1) according to any one of the preceding claims, wherein the inner wall (14) and the outer wall (15) of the tube (3) are made of a thermally conductive material. 8. A storage capacity thermal device (1) according to any one of the preceding claims, in which the receiving space (20) of the tube (3) houses at least one thermally conductive element (42). 9. A storage capacity thermal device (1) according to the preceding claim, wherein the thermally conductive element (42) comprises at least one metal fin (43). 10. thermal storage capacity device (1) according to one of claims 8 or 9, wherein the outer wall (15) and the inner wall (14) of the tube (3) are concentric, at least the thermally element conductor (42) connecting the outer wall (15) to the inner wall (14).