EP3271677A1

EP3271677A1 - Thermal battery, in particular for a motor vehicle, and corresponding use

Info

Publication number: EP3271677A1
Application number: EP16713791.8A
Authority: EP
Inventors: Kamel Azzouz; Julien Tissot; Patrick Boisselle
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2015-03-19
Filing date: 2016-03-21
Publication date: 2018-01-24
Also published as: KR20170128559A; FR3033946A1; FR3033946B1; WO2016146851A1

Abstract

The invention relates to a thermal battery (1), in particular for a motor vehicle, configured for a heat-transfer fluid to pass therethrough, and comprising a heat-storage material. According to the invention, the thermal battery (1) comprises: at least one first heat-exchange compartment (3A) and at least one separate second heat-exchange compartment (3B), each heat-exchange compartment (3A, 3B) being in fluid communication with an associated intake (17) and an associated outlet (19) for a dedicated heat-transfer fluid, and also comprising an associated heat-storage material, for a heat exchange between the dedicated heat-transfer fluid and the associated heat-storage material. The invention also relates to the use of such a thermal battery (1) in at least two separate heat-management loops, in particular in a motor vehicle.

Description

Thermal battery, in particular for a motor vehicle, and use

corresponding

The present invention relates to the field of thermal batteries, especially for a motor vehicle, and more specifically to thermal batteries comprising a thermal storage material, such as a phase change material. The invention also relates to the use of such a thermal battery in particular in thermal management loops for a motor vehicle.

These include latent heat batteries for storing and returning heat through a phase change material.

Thermal batteries are generally used for heating the passenger compartment, especially in electric and hybrid vehicles or for preheating a heat transfer fluid in a thermal management loop.

Thermal batteries can also be used for preheating engine oil or automatic gearbox oil of internal combustion engine vehicles.

For electric vehicles, thermal storage is performed when charging the electric battery. During travel, the thermal energy thus stored is available when the passenger compartment requires the start of heating, the thermal battery will heat the heat transfer fluid before passing through a heat exchanger for heating the cabin. The energy provided by the thermal battery is thus saved on the electric battery.

For hybrid vehicles, the thermal storage is also done during the charging of the electric battery, and further when the engine goes into thermal mode.

For vehicles with internal combustion engines, the energy stored in the thermal battery is charged during a previous run when the engine was warm. This stored energy is then used when starting the vehicle to reduce friction when the engine is cold and the oil is viscous. Indeed, these rubs lead to overconsumption of fuel during the first minutes of use of the vehicle. Thus a thermal battery can then be placed on the transmission fluid, coolant or engine oil circuits.

Such a thermal battery generally comprises, according to a so-called tube and fin technology, a plurality of heat exchange tubes for the circulation of heat transfer fluid, and the phase change material is in contact with the heat exchange tubes. As a variant, the thermal battery forms an enclosure inside which a phase-change material is placed, in particular in encapsulated form, and the coolant circulates in contact with these capsules.

The performance of the thermal battery is thus dependent on the phase-change material that it can contain coupled with the temperature conditions of the coolant according to the application in the vehicle.

In addition, the thermal battery can only be used for a given application in the vehicle. Consequently, depending on the number of loops or thermal management circuits to which it is desired to add such a thermal battery, as many thermal batteries as applications are necessary.

One of the aims of the present invention is to overcome at least partially the drawbacks of the prior art and to propose an improved thermal battery allowing in particular the lowest possible pressure drops. For this purpose, the subject of the invention is a thermal battery, in particular for a motor vehicle, configured to be traversed by a heat transfer fluid and comprising a thermal storage material,

characterized in that the thermal battery comprises:

at least one first heat exchange compartment and at least one second heat exchange compartment,

each heat exchange compartment being on the one hand in fluid communication with an associated intake and an associated outlet for a dedicated heat transfer fluid, and on the other hand comprising an associated thermal storage material, for a heat exchange between the dedicated heat transfer fluid and the associated thermal storage material.

The heat exchange between a heat transfer fluid and a thermal storage material associated in a heat exchange compartment is performed independently of the other heat exchange compartment. The same thermal battery can therefore integrate within it several thermal storage materials and several fluids to meet the different needs encountered in the vehicle. We obtain a multi-function thermal battery.

Such a thermal battery according to the invention also makes it possible to optimize the thermal storage capacity, while decreasing the thermal losses towards the outside.

In addition, according to a particular embodiment, the heat battery can accommodate within it several heat transfer fluids having in particular different thermal conditions, so that the same thermal battery can be used for various applications including the motor vehicle. Of course, it is also conceivable that the same heat transfer fluid circulates in the different thermal exchange compartments of the thermal battery.

According to a preferred embodiment, the thermal battery comprises an enclosure and at least one partition wall arranged in the enclosure so as to separate two heat exchange compartments.

The partition wall may comprise at least one sealed wall.

Alternatively or additionally, the partition wall may comprise at least two watertight walls and at least one thermal insulation interposed between the two watertight walls.

Thanks to this separation wall, the heat exchange compartments can not be in fluid communication with each other, which allows a completely dissociated use of one or other of the heat exchange compartments of the battery thermal, depending on the desired application in particular in the motor vehicle.

The partition wall may furthermore comprise at least one heating means, such as at least one screen-printed heating plate, making it possible to improve the thermal storage.

According to an advantageous embodiment, at least one first heat exchange compartment comprises a first thermal storage material, and at least one second heat exchange compartment comprises a second thermal storage material distinct from the first thermal storage material. The second thermal storage material is for example of different composition of the first thermal storage material.

In particular, the first heat exchange compartment comprises a first phase change material and the second heat exchange compartment comprises a second phase change material with a phase change temperature different from that of the first phase change material. .

By way of example, the first phase change material has a phase change temperature of the order of 60 ° C to 110 ° C, and the second phase change material has a phase change temperature of 100 ° C. order of 50 ° C to 95 ° C.

It is therefore possible to use thermal storage materials, such as different phase-change materials within the same thermal battery. The phase change materials are respectively in a separate heat exchange compartment, thus avoiding any risk of chemical reaction between them, which allows the use of the most suitable phase change materials according to the desired application regardless of the use of another phase change material in another thermal exchange compartment of the thermal battery.

The thermal battery advantageously comprises a separate fill port for each phase change material.

Alternatively, it is also possible to use the same phase-change material in the different thermal exchange compartments of the thermal battery. According to an exemplary embodiment, the thermal battery comprises a bundle of heat exchange tubes, a heat exchange tube comprising at least one heat transfer fluid circulation channel, and at least one thermal storage material able to circulate in the contact heat exchange tubes.

In this case, the partition wall provides a sealing function and separation between the thermal storage materials of two thermal exchange compartments juxtaposed with the thermal battery. According to another exemplary embodiment, the thermal battery has a common enclosure in which the thermal storage material or materials are encapsulated in a plurality of reservoirs, for example of generally cylindrical or spherical general shape, and in which fluids are circulating. coolants in contact with the capsules of thermal storage materials.

In this case, the partition wall provides a sealing function and separation between heat transfer fluids able to flow in two thermal exchange compartments juxtaposed with the thermal battery.

According to a particular embodiment, the thermal battery further comprises at least one device for holding encapsulated thermal storage materials, disposed between the reservoirs of the encapsulated thermal storage materials themselves and between the reservoirs of the encapsulated thermal storage materials and the enclosure of the thermal battery. It may be one or more grids having a plurality of meshes, the encapsulated storage materials being intended to pass through the meshes of a grid.

The thermal battery may further comprise one or more of the following features, taken separately or in combination:

the thermal battery has a generally parallelepipedal or cylindrical general shape,

the partition wall is arranged substantially parallel to the longitudinal direction of the thermal battery,

the partition wall is arranged substantially transversely to the longitudinal direction of the thermal battery,

the partition wall is arranged substantially parallel to the direction of flow of the heat transfer fluid or fluids,

the thermal battery comprises at least one common thermal insulation means for said at least two heat exchange compartments, and

- The first heat exchange compartment and the second heat exchange compartment have different volumes, allowing them to be used in a dissociated manner in different applications.

The invention also relates to the use of the same thermal battery according to the invention in at least two thermal management loops, in particular in a motor vehicle.

Other features and advantages of the invention will emerge more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which:

FIG. 1 is a perspective view of a thermal battery according to a first embodiment,

FIG. 2 is a slightly perspective cross-sectional view of the thermal battery of FIG. 1;

FIG. 3 is a perspective view of a double wall partition of a thermal battery of FIG. 1 or 2,

FIG. 4a is a perspective view of a single wall partition wall of a thermal battery of FIG. 1 or 2, having an integrated heating means,

FIG. 4b is a perspective view of a double-walled partition wall of FIG. 3 having an integrated heating means,

FIG. 4c is an enlarged view of a part of FIG. 4a showing the heating means of the partition wall,

FIG. 5 is a perspective view of a thermal battery according to a second embodiment,

FIG. 6 is a perspective view of a thermal battery according to a third embodiment,

FIG. 7 shows a schematic representation in perspective of internal elements of a thermal battery according to the third embodiment of FIG. 6,

FIG. 8 is a perspective view of a thermal battery according to a fourth embodiment,

FIG. 9 is a slightly perspective cross-sectional view of the thermal battery of FIG. 8;

FIG. 10 is a perspective view of a thermal battery according to a fifth embodiment, FIG. 11 is a diagrammatic and simplified representation of a thermal battery of FIG. 1 arranged in two separate thermal management loops.

In these figures, substantially identical elements have the same references.

The elements of Figures 5 to 10 with the references of the elements of Figures 1 to 4c preceded by a hundred 1, 2, 3 or 4 correspond to the elements of Figures 1 to 4c and are not described again in detail.

Thermal battery

The invention relates to a thermal battery 1, 101, 201, 301, 401.

This may include a latent heat battery, also known as LHB for the English "Latent Heat Battery".

The thermal battery 1, 101, 201, 301, 401 is configured to be traversed by one or more heat transfer fluids. In the remainder of the description, heat transfer fluid is understood to mean any fluid that makes it possible to transport heat or cold between two media.

The thermal battery 1, 101, 201, 301, 401 is further provided with one or more thermal storage materials contained or encapsulated in the thermal battery 1, 101, 201, 301, 401, so as to allow a heat exchange between a thermal storage material and an associated heat transfer fluid.

In operation, the thermal battery 1, 101, 201, 301, 401 makes it possible to store and then restore heat via a thermal storage material or materials, to a heat transfer fluid.

More specifically, the thermal battery 1, 101, 201, 301, 401 comprises at least a first heat exchange compartment 3 A and a second heat exchange compartment 3B, so that a heat exchange between a coolant and an associated thermal storage material may take place in one of the heat exchange compartments 3A or 3B independently of the other heat exchange compartment.

Various embodiments of such a thermal battery 1, 101, 201, 301, 401 multi-fluid and multi-material thermal storage are described below. The following achievements are examples. Although the description refers to several embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined to provide other embodiments.

First embodiment

Figure 1 is a schematic view of a thermal battery 1 according to a first embodiment of the invention.

According to the first illustrated embodiment, the thermal battery 1 has a generally parallelepipedal general shape.

The battery 1 comprises an enclosure 5. According to this first embodiment, the enclosure 5 also has a generally parallelepipedal general shape.

The enclosure 5 is made of a material whose sealing characteristics, thermal insulation and mechanical strength are sufficiently high to withstand the conditions of use of such a thermal battery in a motor vehicle, for example aluminum or thermostable plastic. In a variant, it may also provide an insulating material to be placed over the wall of the enclosure to further isolate the battery from the outside environment.

In order to distinguish the two heat exchange compartments 3A and 3B, the heat battery 1 comprises at least one partition wall 7. This partition wall 7 is provided sealed against heat transfer fluids and thermal storage materials on both sides of the partition wall 7. Thus, the heat exchange compartments 3A and 3B are not in fluid communication with each other.

The location of the partition wall 7 is shown schematically by dashed lines in FIG. 1. In this example, the partition wall 7 is arranged in the interior space defined by the enclosure 5, as can be seen more clearly in FIG. 2. More specifically, the partition wall 7 is in this example arranged substantially parallel to the longitudinal axis L of the thermal battery 1, and therefore the enclosure 5. The partition wall 7 is here arranged over the entire length of the enclosure 5 (see FIGS. 1 and 2).

The partition wall 7 can be made in one piece with the enclosure 5.

Alternatively, the partition wall 7 can be reported and fixed on the enclosure 5 by any appropriate means.

The partition wall 7 is for example made by a wall of generally parallelepipedal shape.

According to a variant illustrated in Figure 3, the partition wall 7 may have at least two walls 70 assembled.

Advantageously, at least one thermal insulator 71 may be interposed between the walls 70.

The walls 70 and the optional heat insulator (s) 71 may be assembled by any appropriate means.

Furthermore, it can be provided that the partition wall 7 comprises at least one heating means. By way of nonlimiting example, the partition wall 7 simple (Figure 4a) or at least two walls 70 (Figure 4b), may have at least one heated screen-printed plate 72 is more visible in Figure 4c.

The heating means integrated in the partition wall 7, such as a heated screen-printed plate 72, makes it possible to heat-charge the thermal battery 1, for example when charging an electric battery of the vehicle. The storage of heat energy within the thermal battery 1 is improved.

According to an alternative not shown, it is possible to provide Peltier cells, in particular in the case of a low temperature storage. In the case where the two heat exchange compartments 3A and 3B are thermally insulated, the charging temperatures can be regulated independently of one another. In the case of a partition wall 7 single wall, the charging temperature can be the same on both sides.

As said above, the heat battery 1 is intended to be crossed on the one hand by at least one heat transfer fluid. Heat transfer fluids are for example those used in applications such as preheating, heating the passenger compartment, namely the coolant, the transmission oil or the engine oil. Fluids such as windshield washer fluid, refrigerants or any other fluid used in a car can be used according to the invention.

For this purpose, as can be seen more clearly in FIG. 2, the thermal battery 1 comprises a plurality of circulation channels 9 for at least one coolant. These circulation channels 9 may be defined for example by tubes or alternatively by juxtaposition of plates.

In the example illustrated in FIGS. 1 and 2, the thermal battery 1 comprises a bundle of stacked heat exchange tubes 11 defining the circulation channels 9.

According to the first embodiment illustrated in FIGS. 1 and 2, the heat battery 1 comprises heat exchange tubes 11 in the two heat exchange compartments 3A and 3B.

In this example, the partition wall 7 is arranged substantially parallel to the heat exchange tubes 11. The partition wall 7 is in this case also arranged substantially parallel to the flow direction of the heat transfer fluid.

The set of heat exchange tubes 9 may be identical.

It could alternatively be provided that the beam comprises heat exchange tubes 9 of different structure in the two heat exchange compartments 3A and 3B.

In addition, it is possible to provide the same heat transfer fluid able to circulate in the circulation channels 9 present in the first heat exchange compartment 3 A and in the circulation channels 9 present in the second heat exchange compartment 3B.

As a variant, a first dedicated heat transfer fluid can circulate in the circulation channels 9 of the first heat exchange compartment 3A while a second dedicated heat transfer fluid can circulate in the circulation channels 9 of the second heat exchange compartment 3B. The first heat transfer fluid and the second heat transfer fluid may be of the same nature or on the contrary be of a different nature. The thermal battery 1 may furthermore comprise interleaves 13 placed in each case between two adjacent heat exchange tubes 11, also between a heat exchange tube 11 and the enclosure 5. The function of the spacers 13 is to increase the heat exchange surface. In order to facilitate the understanding of FIG. 2, the spacers 13 are only partially and schematically represented but are advantageously present throughout the heat battery 1.

The spacers 13 may for example be made in the form of fins. The enclosure 5 is arranged around the heat exchange bundle comprising the plurality of heat exchange tubes 11 and possibly the spacers 13.

According to the first embodiment illustrated in FIG. 1, the thermal battery furthermore has two collectors 15, made here in the form of collector plates 15 and arranged on either side of the heat exchange bundle, that is to say in this example, say at the longitudinal ends of the heat exchange tubes 9. The collector plates 15 also ensure a closure of the heat exchange bundle.

In addition, in order to allow the circulation of one or more heat transfer fluids in the heat exchange compartments 3A and 3B, the heat battery 1 comprises at least one inlet 17 for the supply of heat transfer fluid, and at least one outlet 19 for the discharge of the heat transfer fluid. This is for example intake manifolds 17 or 19 outlet.

The intake manifolds 17 and outlet 19 are arranged on the thermal battery in fluid communication with at least one heat exchange compartment 3A or 3B. Advantageously, a first intake manifold 17 and a first outlet manifold 19 are arranged in fluid communication with the associated first heat exchange compartment 3A. Similarly, a second intake manifold 17 and a second outlet manifold 19 are arranged in fluid communication with the associated second heat exchange compartment 3B.

The thermal battery 1 can therefore accommodate several heat transfer fluids.

Heat transfer fluids may have different heat properties. Heat transfer fluids can also come from separate circuits. Each heat transfer fluid used can flow independently inside an associated heat exchange compartment 3A or 3B, comprising an intake manifold 17 and a specific outlet pipe 19. Thus, independently of one another, the heat transfer fluids are admitted into the heat battery 1 by the intake manifolds 17, and then are distributed in the heat exchange tubes 11 of the associated heat exchange compartment 3A or 3B. . After passing through the thermal battery 1, the heat transfer fluids emerge via the outlet pipes 19.

In FIG. 1, arrows F schematically represent the coolant flow. Of course, the direction of flow of the coolant can be in one direction or the other.

According to the example shown, the intake manifolds 17 and outlet 19 are formed on the manifold plates 15. More specifically, a manifold plate 15 may have the intake manifolds 17 and the other manifold plate 15 may have the manifolds output 19.

The circulation of the coolant in the two heat exchange compartments 3A or 3B may be in the same direction or alternatively in a circulation in the opposite direction. In this case, each manifold plate 15 may have at least one intake manifold 17 and at least one outlet manifold 19. On the other hand, the thermal battery 1 is intended to include at least one thermal storage material.

The thermal battery 1 is for example intended to include the same thermal storage material in the two heat exchange compartments 3A and 3B.

As a variant, a first thermal storage material may be provided in the first heat exchange compartment 3 A and a second thermal storage material in the second heat exchange compartment 3B.

In this example, the enclosure 5 of the thermal battery 1 forms a reservoir of the thermal storage material. In other words, the thermal storage material, once introduced into the thermal battery 1, is kept around the heat exchange tubes 11 and any spacers 13 through the enclosure 5. The thermal storage material is arranged in contact with at least one heat exchange tube 9 for heat exchange between the thermal storage material and the heat transfer fluid. Thus, the heat transfer is carried out through the walls of these heat exchange tubes 11.

The partition wall 7 makes it possible to separate in a sealed manner the thermal storage materials from each heat exchange compartment 3A or 3B, avoiding any contact and risk of chemical reactions between the thermal storage materials. Thus, one can use several thermal storage materials in the same thermal battery 1.

The thermal storage material is preferably a phase change material known by the acronym MCP in French or PCM for English "Phase Change Material". A phase change material is a material capable of absorbing a certain quantity of heat by passing from one physical state to another, for example during the melting, and also of restoring stored heat by taking up the state original physics, for example by recrystallizing.

More specifically, the phase-change material is provided so as to allow, during certain phases, heat storage from a heat-transfer fluid in the thermal battery 1 and, in other phases, a return of heat from the thermal battery 1 to the coolant.

With such a thermal battery 1 possibly including several thermal storage materials such as phase change materials, it is possible to use the most suitable material for a given use.

It is possible to provide a phase change material with the same phase change temperature or alternatively with a different phase change temperature in the two heat exchange compartments 3A and 3B. The choice depends on the desired phase change temperature. This temperature can range from several hundred degrees for applications on the exhaust, to lower ranges for example of the order of 60 ° C to 110 ° C for the transmission oil or engine oil, or of the order of 50 ° C to 95 ° C for ethylene glycol for example. Likewise, phase change materials having similar latent heat or alternatively having different latent heat in the two heat exchange compartments 3A and 3B may be provided. According to a particular example of an engine cooling loop, when a heat-transfer fluid, for example after being heated through the engine, circulates in contact with the phase-change material, the coolant is cooled by the change-over material. phase that takes heat energy for example by passing into the liquid phase. The return of heat can be achieved during a cold start of the car, for quickly heating the heat transfer fluid.

As a variant, the phase-change material may be a material capable of storing frigories and of restoring the refrigerants stored, to and from a heat transfer fluid also called in this case a refrigerant fluid. It may be an air flow intended to modify the thermal parameters of the passenger compartment of the vehicle. Alternatively, it may be a refrigerant.

According to a particular example of an air conditioning loop in a vehicle,

when the air-conditioning loop operates, the phase-change material transfers heat energy to the coolant or coolant, provided sufficiently cold, that is to say at a temperature below the solidification temperature of the material to be changed. phase, and

when the air-conditioning loop is at a standstill, in particular during a short stop of the engine, the coolant or coolant circulating in contact with the phase-change material is cooled by the phase-change material which takes it from the heat energy by passing into the liquid phase.

In this configuration, the thermal battery 1 is for example arranged downstream of an evaporator of the air conditioning loop in the direction of flow of the air flow to the passenger compartment.

It goes without saying that in this case the phase-change material used is selected to have a phase change temperature lower than that of the previous example in the case of a cooling loop of the motor. This maintains the cooling of a passenger compartment of the vehicle during a given stopping period, for example automatic shutdown of the engine when the car comes to a stop. The thermal battery 1 may furthermore comprise at least one filling orifice allowing the filling of phase change material of at least one heat exchange compartment 3A or 3B. The phase change material filler is preferably made in liquid form at the appropriate temperature conditions. A plug 21 (visible in FIG. 1) advantageously closes such a filling orifice.

The filling orifice (s) may be provided on the enclosure 5.

A separate fill port may be provided for each heat exchange compartment 3A or 3B. Thus, the phase change material associated with a given heat exchange compartment 3A or 3B can be introduced independently of the phase change material associated with the other heat exchange compartment. The filling orifices may be arranged on the same side of the enclosure 5 or on two different sides.

Finally, the thermal battery 1 advantageously has a common thermal insulation means for the two heat exchange compartments 3A and 3B.

Such a common thermal insulation means may in particular be arranged around the enclosure 5 of the thermal battery 1, in order to contain the heat stored in the thermal battery 1. There may be mentioned as a non-limiting example, thermal insulation means such as foams, aerogels, fibers or multilayers with or without vacuum.

Second embodiment

FIG. 5 shows a second embodiment of a thermal battery 101.

Only the differences with respect to the first embodiment are detailed below.

According to the second embodiment, the circulation of the fluid or fluids heat transfer is no longer in a direction substantially parallel to the longitudinal direction of the heat exchange tubes 111. On the contrary, according to this second embodiment, it is a so-called "U" circulation as schematized by the arrows F 'in FIG.

In this case, the partition wall 107 is arranged in the enclosure 105 substantially transversely to the longitudinal axis L of the enclosure 105. The partition wall 107 is here arranged over the entire cross section of the enclosure 105 with reference to FIG.

In the example of FIG. 5, the heat transfer fluids associated with the heat exchange compartments 103A and 103B circulate substantially in "U" from the bottom upwards with reference to the representation of FIG. 5. Of course, the heat transfer fluids can flow in the other direction, that is to say from top to bottom according to the representation of Figure 5, or the two heat transfer fluids can flow in opposite directions relative to each other.

Of course, the invention is not limited to thermal batteries 1, 101 of generally parallelepipedal shape.

By way of example, it is possible to provide a thermal battery 201, 301, 401 of generally cylindrical general shape.

Moreover, according to the embodiments previously described, the enclosure 5,

105 of the thermal battery 1, 101 forms a reservoir of the thermal storage material.

Alternatively, the thermal battery 201, 301, 401 may comprise within it a plurality of thermal storage material tanks, here encapsulated phase change material.

Third embodiment

FIG. 6 shows a third embodiment of a thermal battery 201.

Only the differences with respect to the first embodiment are detailed below.

The thermal battery 201 has a generally cylindrical general shape. The enclosure 205 defines an interior space in which a plurality of reservoirs 223, containing encapsulated phase change material, may be placed. The encapsulation of the phase change material provides a tight separation function and allows to have different phase change materials or not in the heat exchange compartments 203 A and 203B of the thermal battery 201.

In the example of FIG. 6, the tanks or capsules 223 are of generally cylindrical general shape. These are called encapsulated phase change material tubes 223.

The tubes of encapsulated phase change material 223 may be arranged substantially parallel to the longitudinal direction L of the thermal battery 201, and therefore of the enclosure 205. Here, the heat transfer fluid circulates in a so-called "U" circulation (shown in FIG. by arrows F ') in the associated heat exchange compartment 3A or 3B.

The thermal battery 201 may further comprise a holding device 225 of encapsulated phase change material tubes 223. The holding device 225 is disposed between the encapsulated phase change material tubes 223 themselves, and also between the 223 encapsulated phase change material tubes and the enclosure 205.

The holding device 225 is advantageously designed to maintain a constant distance between each tube of encapsulated phase change material 223, so as to obtain homogeneity in terms of pressure drops and flow of the coolant. Alternatively, an irregular pitch can be provided between the tubes of encapsulated phase change material 223, in particular to force the passage of heat transfer fluid there.

By way of example, the holding device 225 may comprise a composite material placed within the enclosure 205 except at the inlet and outlet pipes 217 and 219, so as to surround the tubes of material with change of encapsulated phase 223.

According to a more visible alternative in FIG. 7, the holding device 225 comprises at least one gate 225, the tubes of material with phase change. encapsulated 223 then pass through the mesh of the grid to be maintained. The grid or grids 225 may be fixed against the enclosure 205 by any appropriate fixing or locking means.

The encapsulated phase change material tubes 223 may further be held at their longitudinal ends by a manifold 215 (FIG. 6).

In contrast to the first embodiment described, the collectors 215 no longer have intake or outlet nozzles 217, 219 of coolant. Such intake manifolds 217 or outlet 219 can be arranged directly on the wall of the enclosure 205.

In addition, according to this third embodiment the flow of the heat transfer fluid (s) may not be in circulation channels, as described in the first embodiment. In contrast, the heat transfer fluid (s) can circulate inside the enclosure 205 of the thermal battery 201 while coming into contact with the encapsulated phase change material tubes 223.

For this purpose, the encapsulated phase change material tubes 223 must be made of materials capable of withstanding the conditions of use of the thermal battery 201 and the coolant circulating within the enclosure 205. act in particular aluminum or polymeric material such as polyamide.

The thermal battery 201 also has at least one partition wall 207 arranged to separate at least two heat exchange compartments 203A and 203B. The partition wall 207 then makes it possible to separate the heat transfer fluids circulating in the two heat exchange compartments 203A and 203B, and no longer to separate the thermal storage materials from the two heat exchange compartments 203A, 203B as in FIG. first or second embodiment.

Fourth embodiment

FIGS. 8 and 9 show a fourth embodiment of a thermal battery 301. The fourth embodiment differs from the third embodiment in the arrangement of the partition wall 307. For example, the partition wall 307 is arranged substantially transversely to the longitudinal direction L of the thermal battery 301.

More specifically, the partition wall 307 is, in this example, arranged over the entire cross section of the enclosure 305.

The elements 323, 325 respectively correspond to the elements 223, 225 of the third embodiment and are not described again.

Fifth embodiment

A fifth embodiment of a thermal battery 401, shown in FIG. 10, differs from the third embodiment in that the phase change material (s) are encapsulated in tanks 423 of generally spherical shape.

Of course, the partition wall 407 may be arranged in the direction of the length of the thermal battery 401 as illustrated in FIG. 9 but also alternatively substantially transversely to the longitudinal axis L of the thermal battery 401. similarly to the fourth embodiment.

The elements 425 respectively correspond to the elements 225 of the third embodiment and are not described again. Various embodiments of the thermal battery 1 have been described above,

101, 201, 301, 401. Of course, the features of these embodiments can be combined without departing from the scope of the invention.

Use of a thermal battery according to the invention

FIG. 11 is a schematic and simplified representation of the implementation of a thermal battery according to the invention in at least two thermal management loops, in particular of a motor vehicle.

In Fig. 11, a thermal battery 1 according to the first embodiment is shown. Of course, a thermal battery 1, 101, 201, 301, 401 according to one or other of the embodiments described above, can be used indifferently.

The same thermal battery 1 according to the invention may in particular be arranged at both in several separate circuits. Advantageously, the same thermal battery 1 can be arranged in as many separate circuits as separate heat exchange compartments 3A, 3B that this thermal battery 1 has.

In the example of Figure 11, the thermal battery 1 has two heat exchange compartments 3A and 3B, and is arranged in two circuits at a time.

By way of illustrative and nonlimiting example, the thermal battery 1 is arranged both in a motor oil loop B1 and a transmission oil loop B2. The heat transfer fluids are respectively the engine oil and the transmission oil in this example. The heat transfer fluids may be of different types with different operating temperatures.

A loop B 1 or B2 has for example:

At least one heat source 27 or 29,

At least one pump 31 or 33 for driving the coolant, and at least one heat exchange compartment 3 A or 3B of the heat battery 1.

These various elements 27, 31, 3A, respectively 29, 33, 3B are connected to each other by conduits 35, respectively 37, so as to allow circulation of the coolant between the various elements of the loop B1, respectively B2, concerned.

In a particular example, the different elements of each loop B1, B2 can be connected in series according to the order described above. Thus, as shown in a nonlimiting manner in FIG. 11, the heat transfer fluid outlet of a heat exchange compartment 3A, respectively 3B, of the heat battery 1 is for example connected to the heat transfer fluid inlet of a heat source 27, respectively 29, the heat transfer fluid outlet of the heat source 27 or 29 is connected to the heat transfer fluid inlet of the associated pump 31, respectively 33, and the heat transfer fluid outlet of this pump 31 or 33 is connected to the heat transfer fluid inlet of the heat exchange compartment 3 A, respectively 3B, associated with the thermal battery 1.

The heat exchange compartments 3A and 3B separated in a sealed manner at Within the same thermal battery 1 can handle different operating temperatures and have different thermal storage materials, including phase change materials phase change temperatures different. This therefore allows use within distinct loops.

For example, the thermal battery 1 may include:

In the first heat exchange compartment 3 A arranged in the motor oil loop B1, a phase change material with a phase change temperature of the order of 80 ° C., and

In the second heat exchange compartment 3B arranged in the transmission oil loop B2, a phase change material with a phase change temperature of the order of 50 ° C.

Thus, during driving, the thermal battery 1 stores heat produced by one and / or the other heat source 27, 29.

During a cold start of the vehicle, the energy stored in the heat battery 1 allows to quickly heat the transmission oil and / or engine oil. This rapid rise in temperature thus decreases the viscous forces and friction forces decreasing the fuel consumption accordingly. According to an alternative, the thermal battery 1 can be implemented in one or more loops configured to enable,

On the one hand, during certain phases, a storage of the cold from the heat transfer fluid, also called coolant, to the thermal battery 1, and,

• On the other hand, during other phases, a heat return (in this case a cold destocking) of the heat battery 1 to the coolant fluid.

Thus, the thermal battery 1, 101, 201, 301, 401 according to one or the other embodiment allows the use of one or more heat transfer fluids, and likewise of one or more thermal storage materials, such as phase change materials. Due to the presence of at least two heat exchange compartments 3A, 3B; 103A, 103B; 203A, 203B; 303A, 303B; 403A, 403B without any fluidic communication be it coolant or the material or materials of Thermal storage, the thermal battery 1, 101, 201, 301, 401 becomes multi-f unction and can be used in at least two circuits or separate loops of the vehicle.

Such a thermal battery 1, 101, 201, 301, 401 also makes it possible to optimize the thermal storage capacity, while reducing heat losses to the outside.

With the same thermal battery 1, 101, 201, 301, 401 may comprise within it several heat transfer fluids and / or thermal storage materials, the surfaces exposed to the ambient environment are reduced compared to the individual solutions of the prior art . Indeed, according to the form chosen, the inventors have found that it is possible to reduce the surfaces exposed to outward losses by more than 20% in the case of a thermal battery 1, 101, 201, 301, 401 with two separate heat exchange compartments 3A, 3B; 103A, 103B; 203A, 203B; 303A, 303B; 403A, 403B, and more than 30% in the case of three separate heat exchange compartments.

The greater the number of distinct compartments, heat exchange between a heat transfer fluid and an associated thermal storage material, used in the same thermal battery 1, 101, 201, 301, 401, the greater the external surface reduction is important, thus generating a decrease in heat losses proportional to this reduction.

Claims

1. Thermal battery, in particular for a motor vehicle, configured to be traversed by a coolant and comprising a thermal storage material, characterized in that the thermal battery (1; 101; 201; 301; 401) comprises:

at least one first heat exchange compartment (3A, 103A, 203A, 303A, 403A) and at least one second heat exchange compartment (3B; 103B; 203B; 303B; 403B),

each heat exchange compartment (3A, 3B; 103A, 103B; 203A, 203B; 303A, 303B; 403A, 403B) being on the one hand in fluid communication with an inlet (17; 117; 217; 317; 417) and an associated output (19; 119; 219; 319; 419) for a dedicated heat transfer fluid, and further comprising an associated thermal storage material for heat exchange between the dedicated heat transfer fluid and the material. associated thermal storage.

2. Thermal battery according to the preceding claim, comprising an enclosure (5; 105; 205; 305; 405) and at least one partition (7; 107; 207; 307; 407) arranged in the enclosure (5; 205; 305; 405) to separate two heat exchange compartments (3A, 3B; 103A, 103B; 203A, 203B; 303A, 303B; 403A, 403B).

3. Thermal battery according to the preceding claim, wherein the partition wall (7; 107; 207; 307; 407) comprises at least two walls (70) sealed and at least one thermal insulator (71) interposed between the two watertight walls. (70).

4. Thermal battery according to any one of claims 2 or 3, wherein the partition wall (7; 107; 207; 307; 407) comprises at least one heating means, such as at least one screen-printed heating plate ( 72).

The thermal battery as claimed in any one of the preceding claims, wherein at least one first heat exchange compartment (3A; 103A; 203A; 303A; 403A) comprises a first thermal storage material and at least one second heat exchange compartment (3B; 103B; 203B; 303B; 403B) comprises a second thermal storage material distinct from the first thermal storage material.

6. Thermal battery according to the preceding claim, wherein the first heat exchange compartment (3 A, 103 A, 203 A, 303 A, 403 A) comprises a first phase change material, and the second exchange compartment. thermal sensor (3B; 103B; 203B; 303B; 403B) comprises a second phase change material having a phase change temperature different from that of the first phase change material such as a first temperature change material phase change of the order of 60 ° C to 110 ° C, and a second phase change temperature phase change material of the order of 50 ° C to 95 ° C.

7. Thermal battery according to claim 2 taken in combination with any one of the preceding claims, having a substantially parallelepipedal or cylindrical general shape, and wherein the partition wall (7; 107; 207; 307; 407) is arranged substantially parallel to the longitudinal direction (L) of the thermal battery (1; 101; 201; 301; 401).

8. Thermal battery according to claim 2 taken in combination with any one of claims 3 to 6, having a substantially parallelepipedal or cylindrical general shape, and wherein the partition wall (7; 107; 207; 307; 407) is arranged substantially transversely to the longitudinal direction (L) of the thermal battery (1; 101; 201; 301; 401).

9. Thermal battery according to any one of the preceding claims, comprising at least one common thermal insulation means for said at least two heat exchange compartments (3A, 3B; 103A, 103B; 203A, 203B; 303A, 303B; 403A, 403B).

10. Thermal battery according to any one of the preceding claims, in wherein the first heat exchange compartment (3A; 103A; 203A; 303A; 403A) and the second heat exchange compartment (3B; 103B; 203B; 303B; 403B) have different volumes.

11. Use of a thermal battery (1; 101; 201; 301; 401) according to any one of the preceding claims, in at least two separate thermal management loops (B1, B2), especially in a motor vehicle.