FR3068774A1 - DEVICE FOR THERMALLY REGULATING AT LEAST ONE ELECTRICAL ENERGY STORAGE MEMBER - Google Patents

Abstract

The invention relates to a device for the thermal regulation of at least one electrical energy storage element (3), said device comprising a heat exchanger (1) delimiting a coolant circulation circuit, said heat exchanger (1) comprising conduits (11A, 11B) for circulating the coolant and, arranged at a first end of these conduits (11), inlet distributor means (21) for dispensing the coolant in inlet ducts (11A ) in a first direction of circulation and outlet collecting means (22) for collecting the heat transfer fluid flowing in outlet ducts (11B) in a second direction of circulation, inverted with respect to the first direction. According to the invention, said heat exchanger (1) comprises at a second end of said ducts (11) a plurality of turning chambers (313) of the heat transfer fluid between at least one inlet duct (11A) and at least one outlet duct (11B). ), at least a portion of the turning chambers (313) comprising means for restricting the passage of the heat transfer fluid so as to balance the flows of heat transfer fluid in the conduits (11A, 11B) of said heat exchanger (1).

Description

Device for thermal regulation of at least one element for storing electrical energy

1. Domain

The field of the invention is that of thermal regulation of batteries, and more particularly of batteries fitted to a motor vehicle, the propulsion of which is supplied in whole or in part by an electric motor.

More specifically, the invention is in the field of heat exchangers, for example battery coolers, in particular the batteries of a vehicle with electric and / or hybrid motorization.

2. Prior art

The thermal regulation of the battery, in particular in the automotive field and even more particularly in the field of electric and hybrid vehicles, is a problem of importance.

The battery temperature must remain between 20 ° C and 40 ° C in order to ensure the reliability, autonomy, and performance of the vehicle, while optimizing the battery life.

Indeed, when the battery is subjected to temperatures that are too cold, its autonomy decreases sharply. Conversely, when it is subjected to excessively high temperatures, there is a risk of thermal runaway which can go as far as destroying the battery.

In electric or hybrid vehicles, the battery generally comprises several battery modules each comprising several electric energy storage cells (called “electric cells” in the following) linked together so as to create an electric generator of voltage and desired capacity.

In order to regulate the temperature of the battery, it is known to use a thermal regulation device.

The thermal regulation device comprises a heat exchanger positioned directly or indirectly in contact with the battery and traversed by a heat transfer fluid.

The heat transfer fluid can thus absorb the heat emitted by each battery module in order to cool them or, if necessary, it can provide them with heat if the temperature of the battery is insufficient for its proper functioning.

The heat transfer fluids generally used are liquids such as, for example, glycol water.

As illustrated in FIG. 1, such a heat exchanger comprises a bundle of tubes 11 connecting together at least two manifolds 21, 22 in which are connected, in a fixed and sealed manner, corresponding ends of the tubes 11.

A heat transfer fluid can then flow through the tubes 11 and the manifolds 21, 22, according, for example, to a circuit called I-shaped (FIG. 1) in order to thermally exchange with the battery modules 3.

It will be noted that each branch of the heat exchanger consists of adjacent tubes 11 intended to thermally regulate two battery modules 3 arranged along the longitudinal axis of the pair of tubes 11.

The state of the art discusses the various heat transfer fluid circulation circuits which can be used in these heat exchangers.

However, the state of the art dealing with how to balance the flow of fluid in the different branches of the heat exchanger is scarce.

The few existing solutions propose to modify the passage sections of the manifolds and / or tubes and / or pipes supplying the various circuits in parallel, and prove to be expensive.

However, this point is fundamental since the same flow rate in each of the branches of the heat exchanger ensures homogeneous temperature regulation and temperature of the battery modules.

Poor fluid balancing between the different branches of the heat exchanger can lead to high temperature differences between the battery modules.

The main risk, resulting from non-homogeneous regulation of the temperatures of the battery modules, is that one of them fails, for example because its temperature is excessive, causing the vehicle to stop and the need to replace the entire battery pack.

In this context, the present invention aims to provide an improved device for thermal regulation of battery modules, making it possible to solve the drawbacks mentioned above, while being less expensive than current solutions.

3. Summary

To this end, the invention provides a device for thermal regulation of at least one element for storing electrical energy, in particular for a motor vehicle, said device comprising at least one heat exchanger delimiting a circuit for circulation of heat-transfer fluid, said exchanger thermal comprising conduits for circulation of the heat transfer fluid and, arranged at a first end of these conduits, inlet distributor means for ensuring the distribution of the heat transfer fluid in inlet conduits according to a first direction of circulation and means for collecting outlet to ensure the collection of the heat transfer fluid flowing in outlet conduits in a second direction of flow, reversed with respect to the first direction.

According to the invention, said heat exchanger comprises, at a second end of said conduits, several chambers for reversing the heat-transfer fluid between at least one inlet conduit and at least one outlet conduit, at least part of the reversal chambers comprising restriction means of the passage of the heat transfer fluid so as to balance the flow rates of heat transfer fluid in the conduits of said heat exchanger.

The invention thus proposes a device for thermal regulation of at least one element for storing electrical energy, or battery module, which implements a tube heat exchanger delimiting a circuit for circulation of the heat transfer fluid.

This circuit is configured to homogenize the flow and the temperature of the battery modules, without playing on the passage sections of the manifolds and / or of the tubes and / or of the tubes supplying the various circuits in parallel, and this in a relatively inexpensive manner. .

To do this, the exchanger implements several parallel circuits or U-shaped branches each comprising at least one heat transfer fluid inlet pipe or tube and at least one heat transfer fluid outlet pipe connected at one end by a turning chamber , the latter comprising means for restricting the passage of the heat transfer fluid so as to balance the flow rates of heat transfer fluid in the conduits of the heat exchanger.

The implementation of means for restricting the passage of the heat transfer fluid makes it possible to obtain the desired distribution of heat transfer fluid in the different branches of the heat exchanger.

Good fluid balancing between the different branches of the heat exchanger reduces the high temperature differences between the battery modules.

Such an approach is economical and in particular allows the implementation of manifolds having diameters of reasonable size.

According to a particular aspect of the invention, the inlet distributor means and the outlet means of the heat transfer fluid are manifold boxes.

According to a particular embodiment of the invention, the turning chambers are defined in a single turning collecting box into which the second end of said conduits opens.

Advantageously, said reversing manifold comprises one or more watertight internal partitions defining several reversing chambers in each of which open the second end of at least one inlet duct and the second end of at least one outlet duct.

Advantageously, each of said turning chambers comprises means for restricting the passage of the heat transfer fluid taking the form of at least one partition pierced with a passage for the heat transfer fluid or at least a narrowing of the section of said manifold turnaround.

According to another particular embodiment of the invention, the turning chambers are defined in separate turning manifolds and in each of which open the second end of at least one inlet duct and the second end of at least an outlet duct.

Advantageously, the separate reversing manifolds each comprise means for restricting the passage of the heat-transfer fluid taking the form of at least one partition pierced with a passage for the heat-transfer fluid or at least a narrowing of the section of the reversing manifold.

According to a particular aspect of the invention, all or part of the openings in the partitions for restricting the passage of the heat transfer fluid located in the turning chambers have different sections.

According to a particular aspect of the invention, the manifolds forming the inlet distributing means, the outlet collecting means and the turning chambers are tubular and of different diameters.

According to a particular aspect of the invention, said conduits comprise a plurality of channels.

The invention also relates to a heat exchanger implemented in such a thermal regulation device.

In the following description, the concept of “thermal regulation” refers to both the cooling and the heating of a battery module and / or a set of battery modules, designated by the expression “storage element of electric energy ".

4. Figures

Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given by way of simple illustrative and nonlimiting examples, and of the appended figures, namely:

Figure 1 is a schematic view of a heat exchanger (also called cooler) implemented in a thermal regulation device of a battery, according to the prior art;

Figures 2A and 2B are schematic views of a heat exchanger implemented in a thermal regulation device of a battery, according to an embodiment of the invention;

FIG. 3 is a detailed view, in transparency, of the heat exchanger of FIGS. 2A and 2B, at the level of a reversing manifold;

Figures 4 to 6 are partial schematic views of other types of heat exchangers implemented in thermal regulation devices of a battery according to the invention.

The various elements illustrated by the figures are not necessarily represented on a real scale, the accent being placed more on the representation of the general operation of the invention.

5. Detailed description of particular embodiments of the invention

Several particular embodiments of the invention are presented in the following description.

It is understood that the present invention is in no way limited by these particular embodiments and that other embodiments can perfectly be implemented.

FIG. 2A is a schematic view of an embodiment of a heat exchanger (also called cooler) implemented in a thermal regulation device according to the invention.

The latter is intended to equip a hybrid or electric type motor vehicle to thermally regulate one or more batteries forming a source of energy for driving the motor vehicle.

Conventionally, the battery is made up of several battery modules 3, each module 3 being made up of several electrical cells (not visible) which are connected together.

The heat exchanger 1 is positioned here under the modules 3 and allows both the cooling and the heating of these modules 3 according to the conditions of use.

The heat exchanger 1 comprises a bundle of tubes, or conduits, 11 for circulation of a heat transfer fluid

These tubes 11 are straight and of the same length.

They are placed parallel to each other and aligned so as to form a single row in which a coolant, such as glycol water, is intended to circulate.

The tubes 11 are intended to be in mechanical contact or not with several modules 3 of parallelepipedal shape of a vehicle battery, and are advantageously made of a thermal conductive material, such as a metallic material, for example aluminum or a alloy of 'aluminum.

The heat exchanger 1 is thus positioned directly or indirectly in contact with the modules 3 and traversed by a heat transfer fluid.

This heat transfer fluid may be of the refrigerant type, or else a cooling liquid, for example a mixture of water and glycol.

The heat transfer fluid can thus absorb the heat emitted by the modules 3 in order to cool them or, as required, it can provide them with heat if the temperature of the modules 3 is insufficient for their proper functioning.

This heat exchanger 1 makes it possible to limit sudden increases in temperature within the battery and to compensate for the formation of hot spots.

In this embodiment, the tubes 11 have a cross section of substantially oblong shape.

These tubes 11 are here made of extruded aluminum and have a plurality of juxtaposed liquid circulation channels (this is therefore in this example multi-channel tubes).

The bundle of tubes 11 includes a first end and a second end.

As shown in FIGS. 2A and 2B, the first end of a part of the tubes 11 of the bundle opens into a first manifold 21 for entering the fluid. These tubes will hereinafter be called inlet tubes and referenced 11A.

The first end of the other part of the tubes 11 of the bundle opens into a second manifold 22 for fluid outlet. These tubes will hereinafter be called outlet tubes and referenced 11B.

The manifolds 21, 22 for inlet and outlet of fluid (called manifolds in English) extend parallel to the level of the first end of the tubes 11, perpendicular to the longitudinal axis of the latter.

These adjacent manifolds 21, 22 are connected to an inlet E and an outlet S of heat transfer fluid respectively which are located on the same side of the heat exchanger.

In the example of FIGS. 2A and 2B, the tube bundle 11 alternately comprises, from right to left, an inlet tube 11A and an outlet tube 11B.

Each pair consisting of an inlet tube 11A and an outlet tube 11B forms a branch.

The second ends of an inlet tube 11A and an outlet tube 11B of a branch open into a third manifold 31 for fluid return.

Thus, several reversing manifolds 31 extend in an aligned manner at the second end of the branches of tubes 11, perpendicular to the longitudinal axis of the latter and parallel to the manifolds 21, 22 of inlet and outlet of fluid.

Thus, the heat transfer fluid is introduced into the first inlet manifold 21 by the fluid inlet 210, then is distributed in a part of the tubes 11, in this case the inlet tubes 11A, of each branch of the bundle , from the first inlet tube 11A located on the right to the last inlet tube located on the left in FIG. 2B.

The fluid circulates in the inlet tubes 11A and passes through them in a first direction, then passes into the reversing manifolds 31 and circulates in the other direction in the other part of the tubes 11, in this case the tubes outlet, of each branch of the bundle to return to the level of the outlet manifold 22 and be evacuated by the fluid outlet 220.

The manifolds 31, called “turning boxes”, are configured to distribute the heat transfer fluid from the inlet tubes 11A to the outlet tubes 11B

Thus, each branch (made up here of two adjacent multichannel tubes) defines a U-shaped fluid circulation circuit and is associated with a reversing manifold 31.

As described in more detail below, the reversing manifolds 31 allow the balancing of the fluid flow rates between the branches of the heat exchanger 1.

In other words, there are substantially the same flow rates of heat transfer fluid in all of the branches, the return manifolds 31 and the manifolds 21, 22 for inlet and outlet of fluid having substantially identical diameters.

FIG. 3 is a detailed view, in transparency, of the heat exchanger 1 of FIG. 2A at the level of a reversing manifold 31 into which an inlet tube 11A and an outlet tube 11B open.

The reversing manifold 31 is here tubular and its lateral ends are closed by watertight walls 311.

It delimits a turning chamber 313 and has an internal partition 312 pierced with a circular lumen 3121 which constitutes a local restriction on the passage of fluid from the inlet tube 11A to the outlet tube 11B, which generates a pressure drop.

This internal partition 312, called throttle in English, is inserted into a slot made in the wall of the reversing manifold 31, or else it is inserted by one end of the reversing manifold 31.

It is a bulkhead 312 pierced with a calibrated orifice which constitutes a local restriction on the passage of heat transfer fluid.

In a variant, this local restriction of the passage of heat transfer fluid can be obtained by a local narrowing of the section of the reversing manifold 31, that is to say by deformation of the wall of the reversing manifold 31.

It will be understood that the reversing manifolds 31 each comprise at least one perforated partition 312 having a calibrated orifice whose diameter varies as a function of the distance of the corresponding branch from the inlet E of heat transfer fluid.

In this case, the diameter of the orifice of the partitions 312 of the manifolds 31 increases from right to left of the heat exchanger 1 of FIG. 2B. In other words, the diameter of the orifice of the partition 312 of the turning chamber (to the left of the heat exchanger) furthest from the fluid inlet 210 is greater than that of the turning chamber ( to the right of the heat exchanger) closest to the heat transfer fluid inlet E.

The purpose of these partitions 312 pierced is to create a local pressure drop in each branch of the heat exchanger 1, the pressure drop must be different depending on the position of the branch relative to the inlet E of heat transfer fluid of the heat exchanger 1.

According to a particular approach, all or part of the lights 3121 of the partitions 312 have different diameters.

Preferably, the number of partitions 312 having openings of different diameters is minimized in order to limit the manufacturing cost of the heat exchanger, while guaranteeing optimal fluid balancing between the different branches of the heat exchanger.

In another embodiment, the heat exchanger has a single reversing manifold 31 comprising several reversing chambers or compartments delimited by watertight internal partitions fluidly isolating the different branches.

Each turning chamber is associated with a branch of the heat exchanger (that is to say an inlet tube and an outlet tube communicating fluidically via the turning compartment).

In each of the turning chambers is arranged an internal partition pierced.

In a variant, each of the turning chambers comprises a local narrowing of the section of the turning manifold 31.

Figure 4 is a schematic detail view of another configuration of heat exchanger of a thermal regulation device according to the invention, at a reversing manifold.

In this example, each branch comprises four multichannel tubes 11 with two adjacent inlet tubes 11A juxtaposed with two adjacent outlet tubes 11B.

The fluid circulates in the inlet tubes 11A and crosses them in a first direction, then passes into the reversing manifold 31, through a local restriction of the fluid passage formed by a partition 312 pierced with a light , and flows in the other direction in the outlet tubes 11B.

FIG. 5 is a schematic detail view of another configuration of a heat exchanger of a thermal regulation device according to the invention, at the level of a reversing manifold.

In this example, each branch comprises four multichannel tubes 11 with two adjacent inlet tubes 11A arranged in the center of the branch, and two outlet tubes 11B arranged on the side and other two inlet tubes 11A.

The fluid circulates in the inlet tubes 11A and crosses them in a first direction, then passes into the reversing manifold 31, through two local restrictions of the fluid passage each formed by a partition 312 pierced with a light , and flows in the other direction in the two outlet tubes 11B.

FIG. 6 is a schematic detail view of another configuration of a heat exchanger of a thermal regulation device according to the invention, at the level of a reversing manifold.

In this example, each branch comprises three multichannel tubes 11 with a single inlet tube 11A disposed in the center of the branch, and two outlet tubes 11B arranged on either side of the inlet tube 11A.

The fluid circulates in the inlet tube 11A and crosses the latter in a first direction, then passes into the reversing manifold 31, through two local restrictions of the fluid passage each formed by a partition 312 pierced with a light , and flows in the other direction in the two outlet tubes 11B.

The central inlet tube 11A can be of larger dimension insofar as the flow rate of heat transfer fluid circulating inside the latter is twice greater than the flow rate of each of the outlet tubes 11B.

Other aspects and variants

The heat exchanger of the thermal regulation device according to the invention comprises at least two branches, each comprising at least one inlet tube and one outlet tube for the heat transfer fluid.

Each branch of the heat exchanger cools at least one battery module.

The tubular manifolds 21, 22, 31 forming the inlet distributing means, the outlet collecting means and the turning chambers 313 may have different diameters.

The diameter of the reversing manifold (s) may be less than that of the inlet and outlet manifolds, because the flow rate in the reversing manifold (s) is less than that in the inlet and outlet manifolds Release.

In a particular embodiment, only part of the turning chambers comprises means for restricting the passage of the heat transfer fluid.

In a particular embodiment, at least one of the manifolds of the heat exchanger is produced according to a manufacturing technology different from the other manifolds, namely:

- from an electro-welded tube for the inlet and outlet manifolds;

- by stamping and brazing for the reversing manifold (s);

- from plastic.

The heat exchanger can be assembled by brazing, gluing or by means of mechanical connections.

In a particular embodiment, the inlet and outlet of the heat transfer fluid are located on opposite sides of the heat exchanger.

Furthermore, the branches of the heat exchanger may include an even or odd number of tubes.

Claims (10)

1. A device for thermal regulation of at least one element for storing electrical energy (3), said device comprising at least one heat exchanger (1) delimiting a circuit for circulation of heat-transfer fluid, said heat exchanger (1) comprising conduits (11A, 11B) for circulation of the heat transfer fluid and, arranged at a first end of these conduits (11), inlet distributor means (21) for ensuring the distribution of the heat transfer fluid in inlet conduits (11A) according to a first direction of circulation and outlet collecting means (22) for ensuring the collection of the coolant circulating in outlet conduits (11B) according to a second direction of circulation, reversed with respect to the first direction, characterized in that it comprises at a second end of said conduits (11) several reversal chambers (313) of the heat transfer fluid between at least one inlet conduit (11A) and at least one outlet conduit (11B), at at least part of the turning chambers (313) comprising means for restricting the passage of the heat transfer fluid so as to balance the flow rates of heat transfer fluid in the conduits (11A, 11B) of said heat exchanger (1). 2. A thermal regulation device according to claim 1, characterized in that the inlet distributor means (21) and the outlet collecting means (22) of the heat transfer fluid are manifold boxes. 3. A thermal regulation device according to claim 1 or 2, characterized in that the turning chambers (313) are defined in a single turning collecting box (31) into which opens the second end of said conduits (11A, 11B). 4. A thermal regulation device according to claim 3, characterized in that said turning manifold box (31) comprises one or more internal watertight partitions delimiting several turning chambers (313) in each of which open the second end of at least one inlet conduit and the second end of at least one outlet conduit. 5. A thermal regulation device according to claim 4, characterized in that each of said turning chambers (313) comprises means for restricting the passage of the heat transfer fluid taking the form of at least one partition (312) pierced with a light (3121) for the passage of the heat transfer fluid or for at least one narrowing of the section of said reversing manifold (31). 6. A thermal regulation device according to claim 1 or 2, characterized in that the turning chambers (313) are defined in separate turning collecting boxes (31) and in each of which open the second end of at least one conduit. inlet (11A) and the second end of at least one outlet conduit (11B). 7. A thermal regulation device according to claim 6, characterized in that the separate return manifold boxes (31) each comprise means for restricting the passage of the heat transfer fluid taking the form of at least one partition (312) pierced with a lumen (3121) for the passage of the heat transfer fluid or at least a narrowing of the section of the reversing manifold (31). 8. A thermal regulation device according to claim 5 or 7, characterized in that all or part of the openings (3121) of the partitions (312) restricting the passage of the heat transfer fluid located in the turning chambers (313) have different sections . 9. A thermal regulation device according to one of claims 3 to 8, characterized in that the manifolds (21, 22, 31) forming the inlet distributor means, the outlet manifold means and the turning chambers (313 ) are tubular and of different diameters. 10. A thermal regulation device according to any one of claims 1 to 9, characterized in that said conduits (11A, 11B) comprise a plurality of channels.