Patent ID: 12191466

As shown inFIG.1, the invention relates to a heat exchanger1for an electrical component4, in particular for an electrical component of a motor vehicle.

The component4is in this case formed of an electric storage battery comprising electric cells6. Said cells are electrically connected in series and/or in parallel, for example at one end thereof. Said cells are, for example, cylindrical, of circular cross section.

Note that the cells are in this case distributed in four groups, two upper groups7,7and two lower groups9,9′.

Said cells6are preferably distributed regularly in rows oriented in a first direction X, the various rows succeeding one another in a second direction Y, perpendicular to the direction X. The cells are staggered from one row to the next.

The component4is in contact with said exchanger1. In other words, in this case the cells6are in contact with said exchanger1, for example via one end thereof, namely the end opposite the end via which they are electrically connected. Also in other words, the cells6are in contact with the exchanger via a surface forming a disk.

Said exchanger defines one or more exchange surfaces8, in this case four, each corresponding to one of the groups7,7,9,9′ of cells6. The term “exchange surface” thus means a surface facing which the component4to be cooled or heated is intended to extend. Note that, in this case, the exchange surfaces are substantially rectangular.

Said exchanger preferably comprises a contact layer10between said cells6and the exchange surfaces8. Said contact layer10is made of a thermally conductive material. Said material is advantageously deformable so as to absorb any manufacturing disparities between the different cells6and/or a deformation of material owing to differential thermal expansion. It preferably consists of a thermal adhesive for mechanically holding the various cells6on the exchange surfaces8.

Said exchanger preferably comprises a stack of plates, said plates being stacked in a direction Z, at right angles to the directions X and Y. In other words, said plates extend substantially in said directions X and Y. The exchanger has a thickness, in the direction Z, which is much smaller than its length, in the direction Y, and its width, in the direction X.

Said plates are, for example, made of aluminum and/or aluminum alloy. They are assembled, in particular, by brazing.

The stack in this case comprises a first outer plate12facing which a first part of the cells6is positioned on a first face14of said exchanger. Said first outer plate12in this case defines two of the exchange surfaces8, corresponding to the upper groups7,7′ of cells6.

The stack further comprises a second outer plate, which is not visible, facing which another part of the cells6is positioned, on a second face of said exchanger, opposite the first face14of the exchanger. Said second outer plate in this case defines two more exchange surfaces8, corresponding to the lower groups9,9′ of cells6.

The first outer plate12has a substantially flat bottom16and raised edges18. The exchange surfaces8, corresponding to the upper groups7,7′ of cells6, are positioned on said bottom16of the first outer plate12and the corresponding contact layers10are located between said bottom16of the first outer plate12and each of the upper groups7,7′ of cells6.

The second outer plate is flat. The contact layers10corresponding to said other exchange surfaces8are located between said second outer plate and each of the lower groups9,9′ of cells6.

The first outer plate12and the second outer plate between them define a volume inside which a heat-exchange fluid, in particular a heat-transfer fluid, such as glycolated water and/or coolant, running through the exchanger is intended to circulate.

For the circulation of said fluid, said exchanger also has, in this case, inlet20and outlet22connectors in relation to the interior volume defined between the first outer plate12and the second outer plate. Said inlet20and outlet22connectors are substantially on the same straight line oriented in the direction X.

Preferably, the heat exchanger further comprises flanges90for attachment to a support.

As shown inFIG.2, the stack of plates comprises an intermediate plate20, preferably stamped.

The intermediate plate24has a flat peripheral edge26, sandwiched between the raised edges18of the first outer plate12and a peripheral edge of the second outer plate. In other words, said intermediate plate24extends within the interior volume defined between the first outer plate12and the second outer plate. These features promote a good seal of the stack of plates. The circulation of the fluid through the exchanger will now be described.

Said exchanger comprises a first body28defined in this case by a part of the stack of plates, specifically a part located on the right hand side inFIGS.1and2.

Said body28defines at least a primary channel30and a secondary channel32, which are parallel and adjacent. Said channels extend in said second direction Y.

In said primary and secondary channels, the fluid circulates in series from the primary channel30to the secondary channel32, in opposite directions, as shown by the arrows marked34corresponding to the direction of circulation of the fluid in the primary channels30and by the arrows marked36corresponding to the direction of circulation of the fluid in the secondary channels32. The arrows34are shown in dotted line since the primary channels are defined on an inside face of the intermediate plate24and are therefore not visible inFIG.2. The arrows36are shown in solid line since the secondary channels are located on a top face of the intermediate plate24and are therefore visible inFIG.2. The same applies toFIGS.3to6. It is understood that the primary channels30and the secondary channels32are located on either side of said intermediate plate24.

Said primary channels30and said secondary channels32are arranged such that they are alternating, preferably over the whole extent of each of the exchange surfaces8. The heat exchange surfaces8thus allow an exchange of heat between the fluid circulating in said primary and secondary channels, on the one hand, and said component6on the other hand. The intermediate plate24has corrugations for defining a bottom and side walls of the primary channels, not visible inFIG.2, and a bottom38and side walls40of the secondary channels32.

The primary channels30are closed by said second outer plate. On the opposite side to the side of the passage of the fluid, the bottom of the primary channels is secured to the bottom16of said first outer plate12. The secondary channels32are closed by the bottom16of said first outer plate12. On the opposite side to the side of the passage of the fluid, the bottom of the secondary channels is secured to said second outer plate.

The side walls of the primary and secondary channels are preferably substantially straight.

Said first body28further comprises a collector box for the passage of the fluid from the primary channels30to the secondary channels32, in the direction of the arrows marked37. In said collector boxes, the fluid makes a semi-turn, as in the example shown, going from one side of the intermediate plate24to the other. The configuration of the intermediate plate24in this regard will be described in more detail below.

According to the invention, a width11of the primary channels30is less than a width12of the secondary channels32. As explained above, this promotes a uniform exchange of heat between the fluid circulating in the primary and secondary channels, on the one hand and, on the other hand, the component6, over the whole extent of each of the heat exchange surfaces8.

Said primary30and secondary32channels advantageously have a width, respectively I1 and I2, which is constant facing said exchange surfaces8. However, note that, in the exchanger according to the invention, a surface portion of the row of cells at each end of the groups, in the second direction Y, may go beyond said exchange surfaces8(seeFIG.7).

A preferred width ratio I2/I1 between the secondary channel(s)32and the primary channel(s)30′ is between 1.5 and 4, preferably around 2. It was observed that, below 2, uniformization of the exchange of heat at the surface of the exchanger was limited. It was also observed that, above 4, the exchanger had problems in terms of resistance to internal pressure. Moreover, the advantage in terms of uniformization of the exchange of heat at the surface reached a limit when the head losses became too high.

In the example shown, the first body28has two longitudinal edges42, each bordered by two primary semi-channels30. These allow uniformization of the exchange of heat up to the edge of the exchange surfaces8.

As shown in detail inFIGS.3and4, the exchanger1comprises a manifold44for circulation of the fluid to the primary channels30and/or from the secondary channels32. Said manifold44has an inlet46and/or an outlet48for the passage of the fluid, in communication with the inlet20and outlet22connectors, respectively. Said inlet46formed both through the first outer plate12and the intermediate plate24. Said outlet48is formed only through the first outer plate12.

The intermediate plate24has a median portion80defining, in combination with the first and second outer plates, two chambers for circulation of the fluid. A first82of the chambers, visible inFIG.4, forms an inlet chamber in communication with the primary channels30. It is located between said median portion80and the second outer plate. It is supplied by the inlet46of said manifold44. A second84of the chambers, visible inFIG.3, forms an outlet chamber in communication with the secondary channels32. It is located between said median portion80and the bottom of the first outer plate. It is in communication with said outlet48of the manifold44. Said median portion80is preferably located, along the axis Z, at an equal distance from the first and second outer plates.

As will be described in detail below, the exchanger is configured to promote good distribution of the fluid in each of the primary30and secondary32channels, depending on the position of said inlet/outlet46,48.

To this end, the first body28in this case comprises a connection zone50, located between the manifold44and an inlet52of the primary channels30and/or between an outlet54of the secondary channels32and the manifold44.

As shown more clearly inFIG.4, said connection zone50comprises first convergent portions56for the passage of the fluid between the manifold44and the inlet52of the primary channels30. The term “convergent portion”, means a portion of which the cross section, in particular the width, decreases in the direction of flow of the fluid. Said first convergent portions56are extended by a primary neck58in communication with the inlet52of the primary channels30. Said primary necks58extend in the direction of longitudinal extension Y of said primary channels30, each of the primary necks58retaining a constant width.

That being so, a width of the primary necks58differs depending on how close said primary necks58are to the fluid inlet46of the manifold. The primary neck or necks closest to said inlet46of the manifold44have a smaller width than the primary neck or necks58furthest away from said inlet46of the manifold44. In this case, the three primary necks58closest to the inlet46of the manifold44have substantially the same width and the primary neck58furthest away, on the right hand side in the figure, has a greater width.

As shown more clearly inFIG.3, said connection zone50further comprises second convergent portions60for the passage of the fluid between the manifold44and the outlet54of the secondary channels32. Said second convergent portions are extended by a secondary neck62in communication with the manifold44.

Said secondary necks62extend in the direction Y of longitudinal extension of said secondary channels32, each of the secondary necks62retaining a constant width.

That being so, a width of the secondary necks62differs depending on how close said secondary necks are to the fluid outlet48of the manifold44. The secondary neck or necks closest to said outlet48of the manifold44have a smaller width than the secondary neck or necks62furthest away from said outlet48of the manifold44. In this case, the secondary necks62have a width which increases in the direction away from said outlet48of the manifold44, the position of which, in projection, is marked S in the figure.

The secondary necks62are between the first convergent portions56. This moreover has the effect of modifying the size of an inlet width of said first convergent portions56, the first convergent portion or convergent portions56located in the vicinity of the inlet46of the manifold44having a smaller opening than the first convergent portion or convergent portions56furthest away.

The intermediate plate24has corrugations for defining a bottom and side walls of the first and second convergent portions56,60and of the primary and/or secondary necks58,62. The bottom of the first convergent portions56and of the primary necks58is located at the same level, in the direction Z, as the bottom41of the primary channels30. The bottom40of the second convergent portions60and of the secondary necks62is located at the same level, in the direction Z, as the bottom40of the secondary channels32. The side walls of the first and second convergent portions56,60and of the primary and secondary necks58,62are respectively in the continuation of the longitudinal walls41,40of the primary and secondary conduits30,32.

Said manifold44comprises primary stamped portions64, protruding inFIG.4, for controlling the flow of the fluid between the inlet46of the manifold44and the primary channels30and secondary stamped portions66, protruding inFIG.3, for controlling the flow of the fluid between the secondary channels32and the outlet48of the manifold44.

Said primary and secondary stamped portions64,66have different shapes depending on their position in the manifold44, for example a substantially circular, elongate, chevron or three-branched star shape.

InFIG.4, it can be seen that some of the primary stamped portions64are located at the inlet of the first convergent portions56. Those closest to said inlet46of the manifold44have a chevron shape while those furthest away have an elongate shape. Others are located on the same line, in the direction X, as said inlet46of the manifold44. Those closest have a three-branched star shape while the others have an elongate or circular shape.

InFIG.3, it can be seen that some of the secondary stamped portions66are located at the outlet of the second convergent portions60. Those closest to said outlet48of the manifold44have a chevron shape while those furthest away have an elongate shape. Others are located on the same line, in the direction X, as said outlet48of the manifold44. Those closest have a three-branched star shape while the others have an elongate or circular shape.

Again inFIG.4, note that said manifold44comprises a stamped portion68, referred to as the inlet stamped portion, creating a chamber70for distribution of the fluid in the vicinity of the fluid inlet46. Said inlet stamped portion68is oriented identically to the secondary stamped portions66. Said inlet stamped portion68has an annular configuration. It makes it possible to prevent excessive speed of the fluid entering the manifold44, given the low height of the inlet chamber82.

In an alternative that has not been shown, said inlet stamped portion and the first convergent portion associated with one of the primary channels, located in the vicinity of said inlet of the manifold, are in the continuation of one another.

The intermediate plate24has corrugations for defining the primary64and/or secondary66stamped portions. An apex of the primary stamped portion64is located at the same level, in the direction Z, as the bottom of the secondary channels32. An apex of the secondary stamped portion66is located at the same level, in the direction Z, as the bottom of the primary channels30.

As shown inFIGS.5and6, said intermediate plate24defines a bottom92and side walls94of the collector boxes for passage of the fluid from the primary channels30to the secondary channels32.

Said collector box has hollows72forming deflector surfaces74for guiding the fluid in said box from one of the primary channels30to the neighboring secondary channels32.

Said intermediate plate24has, at said collector boxes, slots76, each slot76being located facing an emerging end of one of the secondary channels32to allow the passage of the fluid from one side of the plate to the other. The slots76are made, for example, by removing material before stamping the intermediate plate24or by puncturing during stamping.

In an alternative that has not been shown, the intermediate plate consists of a corrugated fin defining said primary and secondary channels, the collector box, and even the connection zone being defined by stamping said first and/or second outer plates.

Referring again toFIG.1, as will have been understood, the exchanger in this case comprises a second body78, symmetrical to the first body28about the manifold44.

The stack of plates defines said manifold44, said first body28and said second body78.

As is clear from the above, the component4is in contact with said first body28and/or said second body78facing said primary and secondary channels30,32. More specifically, the cells6are located on each side of said first body28and of said second body78. They are preferably secured to said first and/or second body28,78.

As shown more clearly inFIG.7, each of the cells6is facing both one of the primary channels30,30′ and one of the secondary channels32, most of the end surface of the cells facing one of the secondary channels32.

It can also be seen in this figure that said connection zone has an extension, along the axis Y, substantially identical to the diameter of the cells6.