Patent Publication Number: US-2022227221-A1

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

Description:
TECHNICAL FIELD 
     The invention relates to the field of motor vehicles, and more particularly to the field of air circulation for cooling the engine and its equipment. 
     PRIOR ART 
     Motor vehicles, whether of the combustion or electric type, have to discharge the heat generated by their operation, and are equipped with heat exchangers for this purpose. A motor vehicle heat exchanger generally comprises tubes in which a heat transfer fluid, in particular a liquid such as water, is intended to circulate, and heat exchange elements connected to these tubes, often designated by the term “fins” or “inserts”. The fins are used to increase the exchange surface between the tubes and the ambient air. 
     However, in order to further increase the heat exchange between the heat transfer fluid and the ambient air, a ventilation device is often used in addition, to generate or increase a flow of air directed toward the tubes and the fins. 
     As is known, such a ventilation device comprises a blower-wheel fan. 
     The flow of air generated by the blades of such a fan is turbulent, in particular because of the circular geometry of the blower wheel, and generally reaches only part of the surface of the heat exchanger (the circular region of the exchanger that faces the blower wheel of the fan). The exchange of heat is therefore not uniform across the entire surface of the tubes and of the fins. 
     Furthermore, when it is not necessary for the fan to be switched on (typically when the exchange of heat with non-accelerated ambient air is sufficient to cool the heat transfer fluid circulating in the exchanger), the blades partially obstruct the flow of the ambient air toward the tubes and the fins, thus impeding the circulation of air toward the exchanger and thus limiting the exchange of heat with the heat transfer fluid. 
     Such a fan is also relatively bulky, in particular because of the necessary dimensions of the blower wheel in order to obtain effective engine cooling, and this makes incorporating it into a motor vehicle a lengthy and difficult process. 
     This incorporation is all the more complicated in an electric vehicle, the front face of which leaves very little space in which to house the vehicle cooling elements. 
     The object of the invention is to at least partially overcome these drawbacks. 
     SUMMARY 
     To this end, the invention relates to a cooling module for a motor vehicle, comprising at least one heat exchanger defining a surface, referred to as the working surface, at least a first tangential-flow turbomachine and a second tangential-flow turbomachine, each of said turbomachines being capable of creating a flow of air in contact with said working surface, each of said turbomachines comprising a rotor rotatably mounted about an axis of rotation and a volute for housing the rotor, including an air guiding portion and an air outlet from the turbomachine, said turbomachines being arranged so that the air outlet of the first turbomachine is positioned facing the guiding portion of the second turbomachine. 
     The heat exchanger(s) thus advantageously has/have dimensions suitable for being cooled by means of one or more lower cooling openings only. Furthermore, the tangential-flow turbomachines make it possible to create a flow of air through all of the heat exchangers with significantly better efficiency than if a blower-wheel fan were used. 
     In addition, the arrangement of the two turbomachines makes it possible to reduce or even prevent any impact between two air jets leaving the turbomachines, which ensures that the cooling module has satisfactory ventilation and acoustic performance. 
     According to another aspect, the axis of rotation of the first tangential-flow turbomachine and the axis of rotation of the second tangential-flow turbomachine are mounted parallel to each other. 
     According to another aspect, the axis of rotation of the first turbomachine is positioned facing an end edge of the working surface and the axis of rotation of the second turbomachine is positioned facing the inside of the working surface. 
     According to another aspect, the working surface is delimited by a first direction, referred to as the length, and a second direction, referred to as the height, orthogonal to the length, the axis of rotation of the second turbomachine being positioned in a zone between one fifth and four fifths of said height. 
     According to another aspect, the axis of rotation of the second turbomachine is positioned in a zone between one third and two thirds of said height. 
     According to another aspect, in the installed position of the module in the motor vehicle, the outlet of the first turbomachine is positioned facing the guiding portion of the second turbomachine. 
     According to another aspect, the module comprises air guiding shutters pivotably mounted between a closed position of the cooling module and at least one open position of the cooling module. 
     The invention also relates to a motor vehicle with an electric motor, comprising a body, a bumper and a as described above, the body defining at least one cooling opening positioned below the bumper, the cooling module being positioned facing the at least one cooling opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features, details and advantages of the invention will become apparent upon reading the following description. This description is purely illustrative and should be read with reference to the appended drawings, in which: 
         FIG. 1  schematically shows the front part of a motor vehicle with an electric motor, viewed from the side. 
         FIG. 2  is a perspective view of a cooling module according to one embodiment, without guiding shutters. 
         FIG. 3  is a perspective view of a cooling module according to another embodiment, without guiding shutters. 
         FIG. 4  is a side view of the module in  FIG. 3 . 
         FIG. 5  is a perspective view of the module in  FIG. 3 , with guiding shutters. 
         FIG. 6  is a schematic side view of a variant of the module in  FIG. 3 . 
     
    
    
     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 variants are described in detail. 
     It will be noted that, in the preferred examples illustrated, each turbomachine operates by suction, that is, it draws in ambient air and conveys it so that it comes into contact with the various heat exchangers, as will be explained in detail. Alternatively however, each turbomachine operates by blowing, blowing the air toward the various heat exchangers. 
       FIG. 1  schematically illustrates the front part of a motor vehicle  10  with an electric motor  12 . The vehicle  10  comprises in particular a body  14  and a bumper  16  carried by a chassis (not shown) of the motor vehicle  10 . The body  14  defines a cooling opening  18 , that is, an opening through the body  14 . Here there is only one cooling opening  18 . This cooling opening  18  is situated in the lower part of the front face  14   a  of the body  14 . In the example illustrated, the cooling opening  18  is situated below the bumper  16 . A grille  20  can be positioned in the cooling opening  18  to prevent projectiles from being able to pass through the cooling opening  18 . A cooling module  22  is positioned facing the cooling opening  18 . The grille  20  in particular provides protection for the cooling module  22 . 
     The cooling module  22  comprises a ventilation device  24  associated with at least one heat exchanger. 
     As is evident from the figures, the ventilation device  1  comprises at least one tangential-flow fan, also referred to below as a tangential-flow turbomachine, which draws in a flow of air F bound for the heat exchanger or heat exchangers. In the embodiments illustrated, the cooling module comprises two turbomachines  28 - 1 ,  28 - 2 , described in detail below. 
     As illustrated, the cooling module  22  essentially includes a housing or fairing  24  forming an internal air channel. The fairing  24  makes it possible to house at least one tangential-flow turbomachine. Here, a rear part of the fairing in particular forms the volute of the tangential-flow turbomachine  28 . 
     As is evident from the figures, the turbomachines  28 - 1 ,  28 - 2  make it possible to cool one or more heat exchangers  30   1 - 30   3 . 
     Each tangential-flow turbomachine comprises a rotor or turbine  32 - 1 ,  32 - 2  (or tangential blower wheel). The turbine is substantially cylindrical. The turbine advantageously includes several stages of blades (or vanes). The turbine is rotatably mounted about an axis of rotation A 32-1 , A 32-2 . 
     The embodiments in  FIGS. 2 to 6  will now be described. 
     As is evident from these figures, the cooling module  22  comprises a first turbomachine  28 - 1  and a second turbomachine  28 - 2 , according to the turbomachine  28  described previously. 
     In  FIGS. 2 to 6 , the assembled heat exchangers define a surface S, referred to as the working surface, a cross-section of which is substantially rectangular in a plane (Y, Z). 
     Preferably, the direction Y corresponds to a horizontal direction, while the direction Z corresponds to a vertical direction, when the module is installed in the motor vehicle. 
     The surface S is delimited by two opposite end edges  38 ,  39  extending in the direction Y, referred to as the length, and by another two opposite end edges  40 ,  41 , in the direction Z. 
     In  FIG. 5 , the surface S corresponds to the rectangle defined by the exchanger  30 , or if there are several exchangers present, by the largest heat exchanger. It is however also possible to juxtapose several exchangers vertically and/or horizontally, in which case the height of the surface S is the sum of the heights of the vertically juxtaposed (stacked) exchangers, and the length of the surface S is the sum of the lengths of the horizontally juxtaposed exchangers. 
     The first and second turbomachines  28 - 1  and  28 - 2  are mounted parallel to each other, that is, the axis of rotation A 32-1  of the turbine  32 - 1  of the first turbomachine  28 - 1  extends parallel to the axis of rotation A 32-2  of the turbine  32 - 2  of the second turbomachine  28 - 2 . 
     In  FIGS. 2 to 6 , the axes of rotation A 32-1 , A 32-2  are parallel to the direction Y, that is, mounted horizontally. Of course, the invention is not however limited to this configuration and the axes of rotation A 32-1 , A 32-2  can be mounted vertically, that is, parallel to the axis Z. 
     As can also be seen in  FIGS. 2 to 6 , the volute of the first turbomachine  28 - 1  comprises a portion  44 - 1  for guiding air around the turbomachine  32 - 1  to an air outlet from the module, with reference sign  46 - 1 . In a known manner, the air guiding portion  44 - 1  advantageously comprises a wall in the shape of a truncated spiral. 
     Similarly, the volute of the second turbomachine  28 - 2  comprises a portion  44 - 2  for guiding air around the turbomachine  32 - 2  to an air outlet from the module, with reference sign  46 - 2 . The guiding portion  44 - 2  advantageously comprises a wall in the shape of a truncated spiral. 
     According to the embodiment in  FIG. 2 , the two outlets  46 - 1 ,  46 - 2  are positioned facing each other. 
     According to the embodiment in  FIGS. 3 to 6 , the air outlet  46 - 1  of the first turbomachine  28 - 1  is positioned facing the guiding portion  44 - 2  of the second turbomachine  28 - 2 , which significantly reduces the sound waves generated by the cooling module, compared to the configuration in which the two outlets are facing each other in  FIG. 2 . 
     This configuration ensures that the air distribution of an air flow F 1  originating from the first turbomachine  28 - 1  via the associated outlet  46 - 1  is substantially the same, and in particular in the same direction as the distribution of an air flow F 2  originating from the second turbomachine  28 - 2  via the associated outlet  46 - 2 . 
     It will be noted that an axis parallel to the direction Z and passing through the middle of the lengths of the assembled heat exchangers is an axis of symmetry of the two assembled turbomachines  28 - 1 ,  28 - 2 . 
     As can be seen in  FIGS. 3 to 5 , the part  44 - 1 ,  44 - 2  of the volute fairing  242  is positioned above the respective outlet  46 - 1 ,  46 - 2 , and the air flows F 1  and F 2  are substantially vertical and downward. 
     When the vehicle is in a damp, or even wet, environment, such as during rain or when passing through a ford, the turbomachine  28 - 1 ,  28 - 2  is protected, as water cannot be stored in the volute but is instead discharged through the outlet  46 - 1 ,  46 - 2 . As a result, any submersion of the cooling module is prevented. 
     As is also evident from the figures, the axis of rotation A 32-1  of the first turbomachine  28 - 1  is positioned facing the end edge  40  of the surface S and the axis of rotation A 32-2  of the second turbomachine  28 - 2  is positioned facing the inside of the surface S. 
     In  FIGS. 3 and 4 , the axis of rotation A 32-2  of the second turbomachine  28 - 2  is positioned in the middle of the height of the surface S. 
     In  FIG. 6 , the axis of rotation A 32-2  of the second turbomachine  28 - 2  is positioned in the upper third of the height of the surface S. 
     The invention is not however limited to these geometries and, depending on the configuration of the heat exchangers and/or the cooling power required for each exchanger, it is possible to position the turbomachines so that they are dedicated to respective exchangers. 
     Advantageously, the axis of rotation A 32-2  of the second turbomachine  28 - 2  is positioned in a zone between one fifth and four fifths of said height, preferably between one third and two thirds of said height. 
     As illustrated in  FIG. 5 , the module  22  is provided with air guiding means  50 - 1 ,  50 - 2  associated with each turbomachine  28 - 1 ,  28 - 2 . 
     Each air guiding means  50 - 1 ,  50 - 2  comprises a set of shutters  52  pivotably mounted between a closed position of the cooling module (as can be seen in  FIG. 4 ) and at least one open position of the cooling module (not illustrated). 
     The open position is particularly advantageous when the vehicle is travelling at high speed, in which case the turbomachines  28 - 1 ,  28 - 2  can be switched off. 
     The number of shutters  52  associated with the first turbomachine  28 - 1  can be identical to or, conversely, different from, the number of shutters  52  associated with the second turbomachine  28 - 2 , depending in particular on the respective positions of the turbomachines.