Cooling module for an electric motor vehicle, comprising a tangential-flow turbomachine

The invention relates to a cooling module (22) for a motor vehicle (10) with an electric motor (12), comprising: —at least one heat exchanger (301-304); —at least one tangential-flow turbomachine (28) capable of creating an air flow that comes into contact with the plurality of heat exchangers (301-304); —a plurality of flaps (36P, 36A) movable between a first position, referred to as the position opening the cooling module (22), and a second position, referred to as the position closing the cooling module (22), said plurality of flaps (36P, 36A) occupying a portion of the cooling module not occupied by said at least one tangential-flow turbomachine (28).

TECHNICAL FIELD

The invention concerns a cooling module for an electric motor vehicle, comprising a tangential-flow turbomachine. The invention also concerns an electric motor vehicle equipped with such a cooling module.

PRIOR ART

A cooling module (or heat-exchange module) of a motor vehicle conventionally comprises at least one heat exchanger and a ventilation device which is designed to generate an air flow in contact with the at least one heat exchanger. The ventilation device thus allows for example creation of an air flow in contact with the heat exchanger when the vehicle is stationary.

In motor vehicles with conventional internal combustion engines, the at least one heat exchanger has a substantially square form, the ventilation device then being a propeller fan of diameter substantially equal to the side of the square formed by the heat exchanger.

Conventionally, the heat exchanger is then placed opposite at least two cooling openings formed in the front face of the body of the motor vehicle. A first cooling opening is situated above the bumper, while a second opening is situated below the bumper. Such a configuration is preferred since the internal combustion engine must also be supplied with air, the engine air intake being conventionally situated in the passage of the air flow through the upper cooling opening.

However, electric vehicles are preferably equipped solely with cooling openings situated below the bumper, further preferably a single cooling opening situated below the bumper.

In fact the electric motor does not need an air supply. The reduction in the number of cooling openings also allows an improvement in the aerodynamic characteristics of the electric vehicle. This is also reflected by a better autonomy and a higher top speed of the motor vehicle.

Under these conditions, the use of a conventional cooling module appears unsatisfactory. Indeed, a majority of heat exchangers are no longer correctly cooled by the air flow coming solely through the lower cooling opening(s).

An object of the invention is to propose a cooling module for an electric motor vehicle without at least some of the above-mentioned drawbacks.

DISCLOSURE OF THE INVENTION

To this end, the object of the invention is a cooling module for a motor vehicle with an electric motor, comprising at least one heat exchanger, at least one tangential-flow turbomachine capable of creating an air flow in contact with the heat exchanger, a plurality of flaps which are movable between a first position, called the open position of the cooling module, and a second position, called the closed position of the cooling module, said plurality of flaps occupying a portion of the cooling module not occupied by said at least one tangential-flow turbomachine.

Thus advantageously, the tangential-flow turbomachine allows creation of an air flow through all heat exchangers with a significantly better efficiency than if a propeller fan were used.

As a preference, the cooling module comprises one or more of the following features, considered alone or in combination:said plurality of flaps is arranged downstream of the at least one heat exchanger relative to the direction of flow of said air flow in the cooling module;said plurality of flaps at least partially forms a rear face of the cooling module;the module comprises a single tangential-flow turbomachine, a rotational axis of which extends in a direction parallel to a length or a width of the at least one heat exchanger;the turbomachine extends in a top part, a bottom part or an intermediate part of the rear face of the cooling module;the module is configured to position said plurality of flaps in the open position when said at least one tangential-flow turbocharger has stopped;said at least one turbomachine is configured to stop when an air flow in the at least one heat exchanger is greater than or equal to a maximum air flow which can be aspirated by said at least one tangential-flow turbomachine;the flaps are of the passive type;the flaps are controlled by an actuator.

The invention also concerns a motor vehicle with an electric motor, comprising a body, a bumper and a cooling module as described above, the body defining at least one cooling opening arranged below the bumper, the cooling module being arranged opposite the at least one cooling opening.

DESCRIPTION OF EMBODIMENTS

In the remainder of the description, elements that are identical or perform identical functions bear the same reference sign. In the present description, for the sake of conciseness, these elements are not described in detail within each embodiment. Rather, only the differences between the embodiment variants are described in detail.

FIG.1illustrates schematically the front part of a motor vehicle10with an electric motor12. The vehicle10comprises in particular a body14and a bumper16carried by a chassis (not shown) of the motor vehicle10. The body14defines a cooling opening18, i.e. an opening through the body14. Here there is only one cooling opening18. This cooling opening18is situated in the lower part of the front face14aof the body14. In the example illustrated, the cooling opening18is situated below the bumper16. A grille20may be arranged in the cooling opening18to prevent projectiles from being able to pass through the cooling opening18. A cooling module22is arranged opposite the cooling opening18. The grille20in particular provides protection for the cooling module22.

The cooling module22is more clearly visible onFIG.2.

As illustrated onFIG.2, the cooling module22essentially comprises a casing24forming an internal channel between two opposite ends24a,24b. The end24ais intended to be arranged opposite the cooling opening18. The opening of the casing24at this front end24aof the channel may be partially blocked by means of a mesh26.

The casing24is here made in two parts241,242which are fixed together by any means accessible to the person skilled in the art. In this case, the two parts241,242are screwed together at a collar. The front part241has substantially the form of a rectangular parallelepiped open on two opposite faces. The rear part242has a substantially more complex form. This rear part242here in particular forms the volute of the tangential-flow turbomachine28.

FIG.3illustrates the cooling device22in which the front part241of the casing24has been removed.FIG.3thus illustrates the presence of a plurality of heat exchangers301-304in the conduit formed inside the casing24. Here, four heat exchangers301-304are provided. Of course, this number of heat exchangers is nonlimiting. Rather, a different number of heat exchangers may be provided in the casing, in particular at least one heat exchanger, and preferably between four and seven heat exchangers, even more preferably four or five heat exchangers. The heat exchangers301-304are illustrated schematically inFIG.3in the form of substantially rectangular plates. In practice and notably, the heat exchangers301-304have in particular a height h30, measured in a substantially vertical direction, which is less than or equal to 350 mm. The heat exchangers301-304are thus particularly well dimensioned for being in contact with an air flow passing through the cooling opening18.

In the example illustrated inFIG.3, all heat exchangers301-304are identical and all have a same height h30. In the case where the heat exchangers301-304have different heights, it is preferred that all these heights are less than or equal to 350 mm.

Preferably, the height h30of the heat exchangers301-304is between 70 mm and 300 mm. This indeed ensures a satisfactory performance of the heat exchangers301-304while retaining a reduced size of these heat exchangers, the size being particularly suitable for the use of a single cooling opening18. Here again, in the case where the heat exchangers301-304have different heights, it is preferred that the height of each heat exchanger301-304is between 70 and 300 mm.

Even more preferably, the cooling module22has a height h22between 70 mm and 300 mm. It is understood that the height h30of the heat exchangers301-304is always substantially less than the height h22of the cooling module22.

To compensate for the relatively low height of the heat exchangers301-304, these may be relatively numerous, in particular up to four or five heat exchangers301-304, even up to seven heat exchangers. Indeed, to achieve performance levels comparable to those of conventional cooling modules, the number of heat exchangers may be doubled by arranging them in pairs, in series, in the circuit of the fluid passing through them. In other words, a heat exchanger of a conventional cooling module may correspond to two heat exchangers or more in the cooling module22, through which the same fluid passes. In this case in particular it is useful if the heat exchangers are arranged one behind the other in the conduit formed by the casing24. The order of the heat exchangers may be determined as a function of a temperature of the fluid passing through them, or a distance of the heat exchanger concerned from a heat source in the circuit of fluid passing through them. Thus the heat exchangers through which a hot fluid flows are arranged further from the end24aof the casing24, intended to be arranged just behind the cooling opening18, than heat exchangers through which a colder fluid flows.

The arrangement of heat exchangers301-304one behind the other in the axial direction X of the cooling module22may also limit the size of the cooling module22in its two other lateral and vertical dimensions. This preferably, the depth p22of the cooling module22is between 12 mm and 140 mm. Also, the width L30of the heat exchangers301-304or of each heat exchanger301-304may lie between 12 mm and 140 mm.

In addition, because of the shape of the heat exchangers301-304, a tangential-flow turbomachine28is preferred. In fact a propeller fan would be unable to create a substantially uniform air flow in contact with the heat exchangers301-304, in particular over substantially the entire length of these heat exchangers301-304, a length measured in the lateral direction Y.

Here, the tangential-flow turbomachine28comprises a turbine32(or tangential impeller). The turbine32has a substantially cylindrical form, as is shown particularly clearly onFIG.5. The turbine32comprises several stages of blades34(or vanes), in this case sixteen stages of blades34. Naturally, this number of stages of blades34is not limiting, and the turbine32may more generally comprise at least one stage of blades34.

Each stage of blades34comprises a same number of blades34evenly distributed angularly around the rotational axis A32of the turbine32. Advantageously, the stages of blades34are angularly offset such that the blades34are not aligned, preferably such that no blade34is aligned with another blade34of another stage of blades34in the lateral direction Y of the cooling module22. This then avoids the blades34of the turbine32generating noise, particularly because of the fact that all the blades32would be working in synchrony. By offsetting the blades34, it is possible rather to ensure that the blades34work in separate groups, which makes it possible to reduce the noise generated. This gives a tangential-flow turbomachine28in which the sound nuisance can be limited. This is particularly important in the case of a cooling module22for a motor vehicle with electric motor, since an electric motor is known to be less noisy than an internal combustion engine. In addition, the cooling module22is intended to be used also when the electric motor has stopped, in particular when the batteries are being recharged. The noise of the tangential-flow turbomachine28may then be considered a nuisance by users.

The blades34of each stage may in particular be offset by half the spacing between the blades34, with respect to each of the two neighboring stages. Thus, a first half of the stages of blades34have blades34which are aligned with one another and which are offset by half the angular spacing between the blades34relative to the blades34of the other half of the stages of blades34. The noise generated by the rotating turbine22can thus theoretically be substantially halved, which corresponds to a reduction of the order of 3 dB in the noise emitted.

Alternatively, the angular offset of the blades34between two adjacent stages of blades34corresponds to the thickness of a blade34.

Alternatively or in addition, the spacing between the blades34may be divided into substantially as many intermediate positions as there are stages of blades34. Thus, the blades34of the various stages of blades34may be offset step-by-step in the same angular direction, along a longitudinal direction of the turbine32. The blades34of the various stages therefore extend substantially in a helix along the various stages of blades34. In this particular case, all the blades34of all the stages of blades34are offset with respect to all the blades34of all the other stages of blades34. This allows an even greater reduction in the noise generated by the rotating turbine32.

Of course, numerous other configurations are accessible to those skilled in the art, allowing all the blades34of all the stages of blades34to be offset relative to all the other blades34of all the other stages of blades34. In particular, based on the preceding configuration in which the blades34of the various stages34extend in the manner of the helix, it is possible to swap the various stages around, without altering their orientation about the longitudinal axis of the turbine32.

The turbomachine28also comprises a motor36(or gear motor) able to drive the turbine32in rotation about its rotational axis A32. Advantageously, the rotational axis A32of the turbine32, which corresponds to the height direction of the turbine32, is oriented substantially parallel to the lateral direction Y of the heat exchangers301-304. The turbomachine28is thus able to create a substantially constant air flow over the entire width of a same heat exchanger301-304. In order to optimize the air flow created, the height h32of the turbine32is substantially equal to the width L30of the heat exchangers301-304.

The motor36is for example able to drive the turbine32in rotation at a speed between 200 rpm and 14,000 rpm. This allows in particular a limitation of the noise generated by the turbomachine28.

The diameter D32of the turbine32is for example between 35 mm and 200 mm as limits. The turbomachine28is thus compact.

As already stated, the rear part242of the casing24forms the volute of the turbomachine28, as can be seen more particularly fromFIGS.4and5. In addition, the cross-section of the conduit formed in the casing24is significantly greater at the end24athan at its opposite end24b. This allows the turbomachine28to create an air flow in the casing24which has a specific pressure, in order to facilitate the passage of said air flow through the conduit through the casing24, despite the presence of the heat exchangers301-304.

As shown inFIGS.7ato7c, and9to12, the cooling module22also comprises a plurality of flaps36.

The flaps36are mounted so as to be movable between a first position, called the open position of the cooling module (FIG.12), and a second position, called the closed position of the cooling module (illustrated onFIGS.9,10,11).

OnFIGS.9and10, the cooling module22comprises several flaps36distributed over several rows and arranged parallel to the rotational axis A32of the single turbomachine28. The set of the plurality of flaps36firstly and the turbomachine28secondly form a rear face FA of the cooling module22. In the rear face, the flaps36occupy a portion separate from the portion occupied by the turbomachine28. Thus the cooling module22is compact and ensures better performance and a saving of electrical current, as will be explained below.

As these figures illustrate, each of the flaps36comprises a wall38mounted pivoting around a rotational axis parallel to the rotational axis A32.

Preferably, in the closed position (FIG.11), the walls38of the flaps36are contiguous, which blocks the entire portion of the face occupied by the flaps36.

In each open position (FIG.12), each wall38locally forms an angle not equal to zero with the surface S, which allows the air flow F to pass through the cooling module22as shown onFIG.12.

OnFIG.7a, the turbomachine28occupies a top zone40of the rear face, in particular in the upper third of the casing24, preferably in the upper quarter of the casing24. This in particular allows protection of the turbomachine28in the case of submersion, and/or limits the space taken up by the cooling module22in its bottom portion. The plurality of flaps36inFIG.7aoccupies a complementary part of the rear face FA, including a median zone42and a bottom zone44.

InFIG.7b, the turbomachine28occupies the median zone42, in particular the middle third of the height of the casing24, for example for reasons of integration of the cooling module24in its environment. The flaps are distributed in two levels, one36-1situated above the turbomachine28and another36-2situated below the turbomachine28.

InFIG.7c, the turbomachine28occupies the bottom zone44of the rear face, in particular the lower third of the casing24, so the space taken up by the cooling module22in its top part can be limited. The plurality of flaps36inFIG.7coccupies a complementary part of the rear face FA.

The cooling module22is configured to position the flaps36in the open position when the tangential-flow turbomachine28has stopped.

Preferably, the turbomachine28stops when a flow of air passing through said plurality of heat exchangers301-304of the cooling module22is greater than or equal to a maximum air flow which can be aspirated by the tangential-flow turbomachine28. This condition is fulfilled in particular at high speed, for example when the vehicle is driving on a motorway.

Such a configuration, because it allows stoppage of the turbomachine as soon as the air flow generated by the speed of the vehicle is sufficient, ensures a real saving of current and thus a longer autonomy of the electric vehicle.

According to a first variant illustrated inFIGS.7a,7b,7candFIG.9, the flaps are of the passive type, i.e. they are not electrically powered. They are referenced36P.

Thus at a low vehicle speeds, the turbomachine28operates and draws in the air flow F which passes through the heat exchangers301-304and opens the flaps36P.

At high vehicle speeds, the turbomachine28stops and the air flow directly generated by the movement of the vehicle passes through the heat exchangers301-304and opens the flaps36.

Advantageously, the flaps are made of plastic material PA6 or PA66.

According to a second variant illustrated inFIGS.7a,7b,7candFIG.10, the flaps are controlled by an actuator. They are referenced36A.

Thus at a low vehicle speeds, the turbomachine28operates and draws in the air flow F which passes through the heat exchangers301-304and opens the flaps36A.

At high vehicle speeds, the turbomachine28stops and the actuator moves the flap36A into the open position.

The invention is not limited to the exemplary embodiments described with respect to the figures, and further embodiments will be clearly apparent to a person skilled in the art. In particular, the various examples can be combined, provided they are not contradictory.

Also, according to the example illustrated inFIG.8, the turbomachine28, and more particularly the turbine32of this turbomachine28, is movable relative to the heat exchangers301-304in the height direction of these heat exchangers301-304. Such a configuration may for example allow precise temporal management of the cooling of some of the heat exchangers301-304.

Also, in the examples illustrated, the turbomachine28functions by suction, i.e. it draws in ambient air and conducts it into contact with the various heat exchangers301-304. Alternatively however, the turbomachine28operates by blowing, blowing the air towards the different heat exchangers301-304.

Also, whereas in the example described with reference toFIGS.2to6, the turbomachine is situated in the casing of the cooling module, the turbomachine may be arranged outside the casing at one end or another end of this casing, depending on whether or not it functions by suction or blowing.

Furthermore, other variants are also possible for the flaps36.

For example, the flaps36may extend orthogonally to the rotational axes A32-1, A32-2.

Also, the flaps36may partially occupy only the surface S. This is the case for example if the flaps36are arranged in every other row.