CONNECTION BLOCK FOR HEAT EXCHANGER AND COOLING DEVICE COMPRISING SAME

Description

The present invention relates to the field of thermodynamics and relates more specifically to a connection block for a heat exchanger, and to a cooling device including this connection block, which are notably intended to be used for the cooling of members of a vehicle.

In an electric or hybrid vehicle, it is common for the electric battery, the electric motor and the power electronics of the vehicle to be cooled by a heat transfer liquid such as water, circulating in a heat transfer liquid circuit which passes through these components to be cooled, the heat transfer liquid itself being cooled by virtue of a heat exchanger which receives, for the one part, the heat transfer liquid, and, for the other part, a refrigerant fluid. The refrigerant fluid is subjected to a thermodynamic cycle in a separate refrigerant fluid circuit using, for example, a compressor, a condenser, an internal heat exchanger and an expansion member.

During rapid charging of the electric battery of an electric or hybrid vehicle, since the electrical current is high, the thermal power to be dissipated in order to cool the electric battery is significant, for example of the order of 10 000 watts. Similarly, when the electric or hybrid vehicle is running at high speed, the thermal power to be dissipated in the electric motor, the power electronics and the electric battery is significant and therefore requires a heat exchanger which is dimensioned accordingly, referred to as a high-performance heat exchanger.

Since the heat exchanger is formed of a bundle of stacked and brazed plates delimiting channels for circulating the refrigerant fluid or the heat transfer liquid, the number of plates of the heat exchanger of the electric or hybrid vehicle is all the greater when it has to dissipate a high thermal power.

Nevertheless, when the electric or hybrid vehicle is being used in a way that consumes less energy, for example during slow charging of the electric battery of the electric vehicle, or when the electric vehicle is running at low speed, the thermal power of the electric battery that is to be dissipated is lower, for example of the order of 4000 watts. However, the efficiency of a “high-performance” heat exchanger is not optimal at medium or light load, because the number of plates and the dimensioning of the channels of such a heat exchanger have been optimized for high-load use. At medium or light load, the distribution of the liquid and gas phases of the refrigerant fluid in the heat exchanger is therefore not homogeneous and is inefficient.

There is therefore a need for a high-performance heat exchanger, notably for an electric or hybrid vehicle, with an improved thermal power and an improved efficiency at light and medium load, making it possible to cool components of the vehicle. The vehicle components to be cooled preferably include the electric battery, the electric motor and the power electronics, but also the interior of the vehicle.

This performance need is coupled, in electric and hybrid vehicles, with a need for compactness of the cooling system in the engine compartment of the vehicle. Specifically, since these vehicles comprise both an electric motor and a combustion engine for example, the size of each component has to be limited as much as possible in order to be able to house this motor and engine and their related systems in the engine compartment. It is therefore notably necessary to be able to connect the high-performance heat exchanger to the other elements of the cooling system without bulky external tubing being required.

The present invention at least partially remedies the drawbacks of the prior art by providing, for the one part, a connection block for a high-performance heat exchanger, making it possible to avoid coupling this heat exchanger to one or more expansion members by tubing, and, for the other part, a compact cooling device. This compact cooling device includes the connection block according to the invention, and a high-performance heat exchanger, wherein the distribution of the refrigerant fluid is homogenized from an inlet to an outlet of the heat exchanger at low, medium or high load.

To this end, the invention proposes a connection block configured to sealingly connect at least one expansion member to a heat exchanger, the connection block comprising at least:

• • an inlet for refrigerant fluid,
  • a branch, a first and a second passage which are internal to the connection block, the connection block being characterized in that it further comprises:
  • a first and a second outlet for refrigerant fluid which are separate from one another, the inlet and the first and the second outlet for refrigerant fluid being arranged on a contact surface with the heat exchanger, and
  • receiving means which are intended to receive the at least one expansion member and are connected to the inlet for refrigerant fluid by the branch, to the first outlet for refrigerant fluid by the first passage and to the second outlet for refrigerant fluid by the second passage.

By virtue of the connection block according to the invention, the heat exchanger can be connected to one or more expansion members without specific tubing. Specifically, the connection block comprises at least as many outlets as expansion members, these outlets being arranged directly on the contact surface with the heat exchanger. The connection block therefore allows the heat exchanger to receive several flows of refrigerant fluid and therefore to distribute them separately in one or more bodies of the heat exchanger, in order to improve the distribution, and notably to reduce pressure losses.

In addition, the expansion member or members are connected to the connection block without tubing, using the receiving means of the connection block. Said connection block is preferably in one piece and made of aluminum, but other materials are of course usable, notably aluminum alloys, and the connection block may also be produced in several pieces.

The branch of the connection block has two ends or more in order to connect the inlet of the connection block to the receiving means, depending on their arrangement, the receiving means being able to comprise one or more receiving chambers.

The contact surface between the connection block and the heat exchanger is substantially planar, in the sense that it has at least one planar surface making it possible, by brazing or welding to an end face of the heat exchanger, to form sealed connections, for the one part, between a high-pressure outlet for refrigerant fluid arranged on this end face and the inlet for refrigerant fluid of the connection block, and, for the other part, between each outlet for refrigerant fluid of the connection block and at least one corresponding inlet of the heat exchanger.

According to an advantageous feature of the connection block according to the invention, the receiving means, the passages and the branch take the form of cutouts in the connection block, in the form of cylinders whose axes are parallel. These axes are preferably orthogonal to the contact surface of the connection block. This implementation of the receiving means, the passages and the branch which are internal to the connection block is simple to machine. It may notably be effected via bores in the connection block, advantageously parallelepipedal and compact. In a variant, these cutouts are produced in the form of right prisms, with a height orthogonal to the contact surface of the connection block.

Advantageously, the receiving means form a first cylindrical cutout orthogonal to the contact surface, the first passage forms a second cylindrical cutout orthogonal to the contact surface, and the first cylindrical cutout joins the second cylindrical cutout at a portion of the connection block in which a section of the first cylindrical cutout is secant to a section of the second cylindrical cutout, without covering it completely. This feature of the connection block also makes it possible to give it compactness.

In one embodiment, the receiving means form a receiving chamber comprising a bearing surface capable of receiving an inlet of said at least one expansion member and a closed volume capable of receiving a refrigerant fluid at the outlet of said at least one expansion member, the branch connecting the bearing surface to the inlet for refrigerant fluid, the first passage connecting the closed volume to the first outlet for refrigerant fluid and the second passage connecting the closed volume to the second outlet for refrigerant fluid. Thus, the receiving chamber forms at least two sealed connections, one between the inlet of the expansion member and the branch of the connection block, the other between one or more outlets of the expansion member and the first and second passages.

In another embodiment of the invention, said at least one expansion member comprises a first expansion member and a second expansion member, the receiving means comprise a first receiving chamber intended to receive the first expansion member and a second receiving chamber intended to receive the second expansion member, and:

• • the first receiving chamber is connected to the inlet for refrigerant fluid by the branch, and to the first outlet for refrigerant fluid by the first passage, and
  • the second receiving chamber is connected to the inlet for refrigerant fluid by the branch, and to the second outlet for refrigerant fluid by the second passage.

Preferably, in this other embodiment:

• • the first receiving chamber comprises a first bearing surface capable of receiving an inlet of the first expansion member, and a first closed volume capable of receiving a refrigerant fluid at the outlet of the first expansion member, the branch connecting the first bearing surface of the first receiving chamber to the inlet for refrigerant fluid, and the first passage connecting the first closed volume to the first outlet for refrigerant fluid, and
  • the second receiving chamber comprises a second bearing surface capable of receiving an inlet of the second expansion member, and a second closed volume capable of receiving a refrigerant fluid at the outlet of the second expansion member, the branch connecting the second bearing surface of the second receiving chamber to the inlet for refrigerant fluid, and the second passage connecting the second closed volume to the second outlet for refrigerant fluid.

In these embodiments, each receiving chamber is for example formed of three coaxial bores which narrow in diameter from a surface on the opposite side from the contact surface, the bore of smaller diameter being configured to receive an inlet of an expansion valve of an expansion member and to form a sealed connection between the inlet of the expansion valve and the branch. The shoulder between the bore of smaller diameter and the bore of intermediate diameter serves for example as bearing surface for the inlet of the extension valve. In a variant, the inlet of the expansion valve is fitted tightly in the bore of smaller diameter or in the branch, so as to realize this sealing. The bore of intermediate diameter is configured to form a closed volume between that part of the expansion member which is comprised in the bore of larger diameter and the inlet of the expansion valve, the closed volume forming a sealed connection between the outlets of the expansion valve and the first and/or the second passage when the expansion member is received in the receiving chamber.

Advantageously in the other embodiment of the invention, the contact surface of the connection block has a first groove forming the inlet for refrigerant fluid and a part of the branch, the branch comprising a first duct starting from the first groove and leading to the first receiving chamber, and a second duct starting from the first groove and leading to the second receiving chamber. This first groove enables efficient distribution of the refrigerant fluid in each receiving chamber of the receiving means.

Advantageously again in this other embodiment of the invention, the contact surface has a second groove which supplies the second outlet for refrigerant fluid and is configured to connect an intake orifice of the heat exchanger to a first end of the second passage, the second passage being produced in the form of a cylindrical cutout, having a second end opposite the first end and forming an opening in the second receiving chamber. This second groove makes it possible to efficiently return the refrigerant fluid from the second receiving chamber to the intake orifice of the heat exchanger.

The invention also relates to a cooling device comprising a connection block according to the invention, a heat exchanger, and an internal heat exchanger comprising a high-pressure outlet manifold and a low-pressure inlet manifold on a terminal plate of the internal heat exchanger, and wherein:

• • the contact surface of the connection block is brazed or welded to an end face of the heat exchanger, an end plate of which on the opposite side from the end face is itself brazed or welded to the terminal plate of the internal heat exchanger, the high-pressure outlet manifold being connected to a pipe which passes through the heat exchanger and serves the inlet for refrigerant fluid of the connection block, the low-pressure inlet manifold being connected to a discharge orifice for refrigerant fluid of the heat exchanger on the end plate, and
  • the heat exchanger comprises:
    • for the one part, a first distribution chamber serving a first body of the heat exchanger, and a first inlet for refrigerant fluid which leads to the first distribution chamber,
    • and, for the other part, a second distribution chamber serving a second body of the heat exchanger, and a second inlet for refrigerant fluid which leads to the second distribution chamber,
      the first outlet for refrigerant fluid of the connection block being connected to the second inlet for refrigerant fluid of the heat exchanger and the second outlet for refrigerant fluid of the connection block being connected to the first inlet for refrigerant fluid of the heat exchanger. In a variant, the first outlet for refrigerant fluid of the connection block is connected to the first inlet for refrigerant fluid of the heat exchanger and the second outlet for refrigerant fluid of the connection block is connected to the second inlet for refrigerant fluid of the heat exchanger.

By virtue of the cooling device according to the invention, the distribution of refrigerant fluid is balanced between the first body of the heat exchanger and the second body of the heat exchanger, thus homogenizing this distribution and reducing pressure losses. Thus, at light or medium load, the efficiency of the heat exchanger is improved.

In addition, when the distribution chambers of the heat exchanger according to the invention are supplied independently, the invention makes it possible to use the first body and/or the second body depending on the thermal power to be dissipated. The cooling device according to the invention additionally has the advantage of being compact.

The first body of the heat exchanger comprises, for example, a first plurality of plates between which first channels intended to receive a refrigerant fluid are arranged, and the second body of the heat exchanger comprises a second plurality of plates between which second channels intended to receive the refrigerant fluid are arranged, the first distribution chamber and the second distribution chamber being capable of providing, sealingly with respect to one another, a first flow rate of refrigerant fluid to the first channels and, respectively, a second flow rate of refrigerant fluid to the second channels.

The first and second channels respectively of the first and second body are preferably all of identical sections and lengths, and the first flow rate is preferably substantially equal to the second flow rate. The first flow rate may specifically differ from the second flow rate in particular depending on different pressure losses between the first and the second channels, in spite of an identical structure of the first and second channels.

In a main embodiment variant of the invention, the first and the second distribution chamber are arranged around a pipe, the latter passing orthogonally through the plates of the first and second plurality of plates, and the cooling device comprises a sealing barrier between the first distribution chamber and the second distribution chamber, the sealing barrier forming an angular cylindrical-sleeve portion around the pipe, and having an opening on the end face of the heat exchanger.

In a secondary embodiment variant of the invention, the first and the second distribution chamber are at least partially delimited by a first helicoidal spiral and a second helicoidal spiral which are intertwined around the pipe.

In this secondary embodiment variant of the invention, the cooling device according to the invention comprises, for example, a first sealing barrier between the first distribution chamber and the second body of the heat exchanger, the first sealing barrier being a spiral plug, and a second sealing barrier between the second distribution chamber and the first body of the heat exchanger, said second sealing barrier being formed by a cylindrical envelope surrounding the first and second spirals facing the first channels, the cylindrical envelope comprising apertures between the first distribution chamber and each of the first channels. The first and second spirals stop for example at the interface between the first channels and the second channels.

In this secondary embodiment variant of the invention, the first and second intertwined spirals define for example two pitches, the first distribution chamber being defined by a first of said pitches which is smaller than a second of said pitches, the second pitch defining the second distribution chamber. In this case, the capacity of the first distribution chamber is smaller than the capacity of the second distribution chamber, the number of first channels being lower than the number of second channels. The ratio of the number of first channels to the number of second channels, and therefore of the first pitch to the second pitch, is dependent on the thermal power that is desired to be dissipated in the first body of the heat exchanger and in the second body of the heat exchanger, these first and second bodies being able to be supplied independently. The dimensioning of the first body is, for example, adapted to the dissipation of a low thermal power in a case of use where an electric or hybrid vehicle is running at low speed. The dimensioning of the second body is, for example, adapted to the dissipation of a medium thermal power in a case of use where an electric or hybrid vehicle is being charged slowly. Used together, the first and second bodies make it possible to dissipate a high thermal power notably in the case of rapid charging of the electric or hybrid vehicle.

As an alternative, in this secondary embodiment variant of the invention, the first distribution chamber has a greater capacity than the second distribution chamber, the first pitch being greater than the second pitch and the number of first channels being greater than the number of second channels.

In yet another implementation, the number of channels in the first body and in the second body is the same.

According to another advantageous feature of the cooling device according to the invention, a plate of the heat exchanger that is disposed at the interface between the first body and the second body does not allow the refrigerant fluid to pass between the first body and the second body. Thus, even outside the distribution chambers, the refrigerant fluid cannot pass from the first body to the second body of the heat exchanger.

The cooling device according to the invention advantageously further comprises the expansion member or the first and the second expansion member.

Other features and advantages of the invention will become more clearly apparent from the description that follows and from a plurality of exemplary embodiments provided by way of non-limiting indication with reference to the appended schematic drawings, in which:

FIG. 1 shows a cooling device according to the invention, in a first embodiment of the invention,

FIG. 2 shows a connection block according to the invention, in this first embodiment of the invention,

FIG. 3 shows, in section, the connection block in FIG. 2,

FIG. 4 shows a cooling device according to the invention, in a second embodiment of the invention,

FIG. 5 shows a connection block according to the invention, in the second embodiment of the invention,

FIG. 6 shows, in section, the connection block in FIG. 5,

FIG. 7 is a front view of a heat exchanger of the cooling device in FIG. 1 or 4, in which the end face of the heat exchanger has been rendered transparent,

FIG. 8 is a view in section of the cooling device in FIG. 1, in a secondary embodiment variant of the invention,

FIG. 9 schematically shows a cooling device according to the invention, in a main embodiment variant of the invention,

FIG. 10 schematically shows the cooling device in FIG. 8, and

FIG. 11 shows a cooling system of an electric or hybrid vehicle comprising the cooling device in FIG. 4.

In a first embodiment of the invention illustrated in FIG. 1, a cooling device 1 according to the invention comprises an expansion member 6, a connection block 30 according to the invention, a heat exchanger 2 and an internal heat exchanger 4.

The expansion member 6 is controlled electronically.

The heat exchanger 2 comprises an inlet 26 for heat transfer liquid and an outlet 28 for heat transfer liquid.

The internal heat exchanger 4 comprises a free end plate on which a high-pressure inlet manifold 42 for refrigerant fluid and a low-pressure outlet manifold 48 for refrigerant fluid are disposed. The opposite end plate of the heat exchanger 4 is a terminal plate brazed to an end plate 211 of the heat exchanger 2, referenced in FIG. 9. As shown in this FIG. 9, at the interface between the terminal plate of the internal heat exchanger 4 and the end plate 211 of the heat exchanger 2, a discharge orifice 24 for refrigerant fluid of the heat exchanger 2 communicates directly with a low-pressure inlet manifold 46 of the internal heat exchanger 4. Likewise at this interface, a high-pressure outlet manifold 44 of the internal heat exchanger 4 communicates with a pipe 29 passing through the heat exchanger 2. The pipe 29 comprises a first end 294 leading into an inlet 370 (referenced in FIG. 2) for refrigerant fluid of the connection block 30 while being arranged in an intake orifice 22 for refrigerant fluid of the heat exchanger 2. The pipe 29 comprises a second end 292 connected to the high-pressure outlet manifold 44 of the internal heat exchanger 4.

It should be noted that the detail regarding the path of refrigerant fluid in the heat exchanger 2 and the internal heat exchanger 4 will be described in more detail below in relation to FIG. 9.

An end face 251 of the heat exchanger 2, on the opposite side from the end plate 211 of the heat exchanger 2, comprising the inlet 26 for heat transfer liquid and the outlet 28 for heat transfer liquid, is brazed to the connection block 30, shown in FIG. 2, on a contact surface 360 of the connection block 30 with the heat exchanger 2.

The connection block 30 is an aluminum block in which bores have been produced orthogonally to the contact surface 360. Notably, on the opposite side from this contact surface 360, means for receiving the expansion member 6 are formed by a receiving chamber 380 produced by three coaxial bores 381, 383, 385 which narrow in diameter from the surface of the connection block 30 on the opposite side from the contact surface 360. This receiving chamber 380 more specifically houses an expansion valve of the expansion member 6.

The last bore 385 of smaller diameter in this receiving chamber is itself pierced by a branch 310 to the contact surface 360 of the connection block 30, this branch 310 forming the inlet 370 for refrigerant fluid of the connection block 30. This branch 310 is in this case also a cylindrical bore, of smaller diameter than the last bore 385 and coaxial therewith. The last bore 385 of the receiving chamber 380 has a bearing surface 386, referenced in FIG. 3, enclosing a periphery of the inlet of the expansion valve of the expansion member 6. This bearing surface 386 thus forms a sealed connection between the inlet of the expansion valve of the expansion member 6 and the inlet 370 for refrigerant fluid of the connection block 30. In a variant, the diameter of the branch 310 is identical to that of the last bore 385. In another variant, the inlet of the expansion valve of the expansion member 6 is held against the shoulder between the last bore 385 and the branch 310, in order to form the sealed connection between the inlet of the expansion valve of the expansion member 6 and the inlet 370 for refrigerant fluid of the connection block 30.

That part of the expansion member 6 which is contained in the bore 381 of larger diameter of the receiving chamber 380 bears against a shoulder between this bore 381 of larger diameter and the bore 383 of intermediate diameter of the receiving chamber 380, closing any passage between the bore 381 of larger diameter and the bore 383 of intermediate diameter. The bore 383 of intermediate diameter thus comprises a closed volume 388 between the expansion valve of the expansion member 6 and the cylindrical surface of this bore 383 of intermediate diameter housing the part of the expansion valve comprising the outlets for refrigerant fluid of this expansion valve. Thus, this closed volume 388 sealingly receives the refrigerant fluid at the outlet of the expansion valve. The refrigerant fluid at the outlet of the expansion valve exits this closed volume 388 via a first passage 330 provided between the cylindrical surface of the bore 383 of intermediate diameter and a first outlet 320 for refrigerant fluid of the connection block 30, and also via a second passage 350 provided between the cylindrical surface of the bore 383 of intermediate diameter and a second outlet 340 for refrigerant fluid of the connection block 30.

The first passage 330 is more specifically formed by a first cylindrical bore 322, continued by a second cylindrical bore of smaller diameter which joins the bore 383 of intermediate diameter of the receiving chamber 380 at a portion of the connection block 30. These first and second bores are produced orthogonally from the contact surface 360.

Viewed in section through a plane parallel to the contact surface 360, the portion of the block in which the first passage 330 joins the closed volume 388 of the receiving chamber 380 would therefore show the first passage 330 and the receiving chamber 380 in the form of round sections of non-empty intersection, but without the one being included in the other. In other words, in this parallel plane, the distance between the axis of revolution of the first bore of the first passage 330 and the axis of revolution of the bore 383 of intermediate diameter of the receiving chamber 380 is smaller than the sum of the radii of the cylinders formed by these bores.

In a variant, the first passage 330 leads completely into the shoulder between the bore 383 of intermediate diameter of the receiving chamber 380 and the last bore 385 of smaller diameter of the receiving chamber 380.

The second passage 350 is produced symmetrically to the first passage 330 with respect to a plane orthogonal to the contact surface 360 passing through a diameter of the cylindrical bore forming the branch 310 of the connection block 30.

FIG. 3 also shows the flows followed by a refrigerant fluid FR inside the connection block 30. The refrigerant fluid FR at the outlet of the pipe 29 passes at high pressure to the inlet 370 of the connection block 30 and enters the expansion valve of the expansion member 6. After expansion in this valve, the refrigerant fluid FR passes from the outlets of this valve at low pressure into the closed volume 388 and emerges from this closed volume 388 via the first passage 330 and via the second passage 350 to the respective outlets 320 and 340 of the connection block 30. This double outlet of the connection block 30 makes it possible to send the low-pressure refrigerant fluid FR to the intake orifice 22 via two separate inlets, that is to say a first inlet 221 and a second inlet 223, respectively supplying a first body 25 of the heat exchanger 2 and a second body 27 of the heat exchanger 2, as illustrated in FIG. 8. This separation of the refrigerant fluid FR into two separate flows makes it possible to better control the pressure losses inside the heat exchanger 2, as will be explained below in relation to this FIG. 8.

In a second embodiment of the invention illustrated in FIG. 4, a cooling device 10 according to the invention comprises a first expansion member 64, a second expansion member 62, a connection block 3 according to the invention, and the heat exchanger 2 and the internal heat exchanger 4 of the first embodiment of the invention. As in the first embodiment of the invention, the connection block 3 comprises a contact surface 36 (referenced in FIG. 5) brazed to the end face 251 of the heat exchanger 2, which is assembled with the internal heat exchanger 4 as in the first embodiment of the invention.

The expansion members 62 and 64 are controlled electronically. In a variant, they are controlled thermally.

The connection block 3 has a lot of features that are similar to those of the connection block 30, and will therefore be detailed to a lesser extent than the latter.

With respect to the connection block 30, the valves of the first and second expansion members 64 and 62 are inserted in the receiving means of the connection block 3, shown in FIG. 5, these receiving means comprising a first receiving chamber 38 housing the expansion valve of the first expansion member 64 and a second receiving chamber 39 housing the expansion valve of the second expansion member 62. These chambers are produced as three cylindrical bores in a similar manner to the chamber 380 of the connection block 30. The respective expansion valves of the expansion members 64, 62 are disposed therein in the same manner.

The inlet 37 for refrigerant fluid FR of the connection block 3 is formed by a first groove 31 carved on the contact surface 36. The last bore of smaller diameter of the receiving chamber 38 is itself pierced by a first cylindrical duct 312 leading into the first groove 31. Similarly, the last bore of smaller diameter of the receiving chamber 39 is itself pierced by a second cylindrical duct 314 leading into the first groove 31. Thus, the receiving chambers 38, 39 are fluidically connected to the inlet 37 for refrigerant fluid of the connection block 3 by a single branch which is internal to the connection block 3, this branch being formed of the first groove 31 and by ducts 312, 314 which are orthogonal to the contact surface 36 and extend the ends of the first groove 31.

As in the first embodiment of the invention, a bearing surface 382 (referenced in FIG. 6) of the last bore of smaller diameter of the first or the second receiving chamber 38, 39 forms a sealed connection between the respective inlet of the expansion valve of the first or of the second expansion member 64, 62 and respectively the first or the second duct 312, 314, therefore between the inlets of these expansion valves and the inlet 37 of the connection block 3.

Contrary to the first embodiment of the invention, the first receiving chamber 38 is connected to only a first outlet 32 of the connection block 3, via a first passage 33. The first passage 33 is produced in the same manner as the first passage 330. Notably, it receives the refrigerant fluid FR at the outlet of the expansion valve of the first expansion member 64 sealingly by virtue of a closed volume 384 (referenced in FIG. 6) comprised between this expansion valve and the bore of intermediate diameter of the first receiving chamber 38. This sealing is realized by virtue of the tight insertion of this expansion valve in the first receiving chamber 38, in the same way as in the first embodiment of the invention.

As in the first embodiment, the first passage 33 is formed of a first cylindrical cutout 326 followed by a second cylindrical cutout of smaller diameter. The first cylindrical cutout 326 is disposed facing the second inlet 223 for refrigerant fluid of the heat exchanger 2.

Similarly, the second receiving chamber 39 is connected to only a second outlet 34 of the connection block 3, via a second passage 35. The second passage 35 is produced in the same manner as the second passage 350. Notably, it receives the refrigerant fluid FR at the outlet of the expansion valve of the second expansion member 62 sealingly by virtue of a closed volume comprised between this expansion valve and the bore of intermediate diameter of the second receiving chamber 39.

In order to connect the second passage 35 to the first inlet 221 for refrigerant fluid of the heat exchanger 2, a second groove is produced on the exchange surface 36 of the connection block 3. A first end of this second groove leads into the second passage 35, and a second end of this second groove is disposed facing the first inlet 221 for refrigerant fluid of the heat exchanger 2. Thus, the second outlet 34 for refrigerant fluid of the connection block 3 is formed by this second groove.

This second embodiment therefore makes it possible to separately control a first flow of low-pressure refrigerant fluid arriving at the first inlet 221 for refrigerant fluid of the heat exchanger 2, and a second flow of low-pressure refrigerant fluid arriving at the second inlet 223 for refrigerant fluid of the heat exchanger 2. Specifically, the first flow is controlled by the second expansion member 62, whereas the second flow is controlled by the first expansion member 64.

The flows of refrigerant fluid FR in the connection block 3 are illustrated by dashed lines in FIGS. 5 and 6.

FIG. 7 shows part of the heat exchanger 2 at the portion of the end face 251 of the heat exchanger in contact with the contact surface 36 or 360 of the connection block 3 or 30. In this FIG. 7, the end face 251 has been rendered transparent, with only apertures 222 and 224 of this end face 251 corresponding respectively to the first inlet 221 and to the second inlet 223 for refrigerant fluid of the heat exchanger 2 being shown. In this figure, the sealing edges of the channels of the heat exchanger 2 therefore appear as multiple lines, and flow disruptors of a first channel of the heat exchanger 2 appear in relief.

As visible in this FIG. 7, the first end 294 of the pipe 29 is arranged in the center of the intake orifice 22 of the heat exchanger 2. This first end 294 projects from the end face 251 of the heat exchanger 2, so as to be inserted in the cylindrical bore forming the branch 310 of the connection block 30, or in the first groove 31 of the connection block 3, without touching the bottom of the first groove 31 such that the refrigerant fluid circulates to the first duct 312 and to the second duct 314.

The first outlet 32, 320 for refrigerant fluid FR of the connection block 3, 30 is placed facing the aperture 224 of the end face 251 so as to supply the second inlet 223 for refrigerant fluid of the heat exchanger 2, and the second outlet 34, 340 for refrigerant fluid FR of the connection block 3, 30 is placed facing the aperture 222 of the end face 251 so as to supply the first inlet 221 for refrigerant fluid of the heat exchanger 2.

In order to receive the first flow in the first inlet 221 sealingly with respect to the second flow in the second inlet 223, inlet sealing means are arranged at the intake orifice 22.

As illustrated in FIGS. 9 and 10, the intake orifice 22 is itself the end of an inlet manifold 23 passing through the heat exchanger 2, this inlet manifold 23 being at least partially surrounded by a cylindrical envelope 235 sealingly serving the first body 25 and the second body 27 of the heat exchanger 2. For this purpose, the inlet manifold 23 comprises a first distribution chamber 231 which is supplied by the first inlet 221 and serves the first body 25 of the heat exchanger 2, and a second distribution chamber 233 which is supplied by the second inlet 223 and serves the second body 27 of the heat exchanger 2. The first and second distribution chambers 231 and 233 are arranged around the pipe 29, as described in detail below.

When the first and the second distribution chamber 231 and 233 are angular cylindrical portions disposed around the pipe 29, as in the main embodiment variant illustrated in FIG. 9, the inlet sealing means comprise the end face 251 of the heat exchanger 2, and walls of an angular cylindrical-sleeve portion 238 around the pipe 29, forming the first distribution chamber 231. These walls which are oriented axially, that is to say in the main direction of extension of the pipe 29, are pressed against the end face 251. Thus, the first flow of refrigerant fluid FR coming from the second outlet 34, 340 of the connection block 3, 30 enters the aperture 222 of the end face 251 and is located in the angular cylindrical-sleeve portion 238, sealingly with respect to the second distribution chamber 233 supplied by the second flow of refrigerant fluid FR coming from the first outlet 32, 320 of the connection block 3, 30.

When the first and the second distribution chamber 231 and 233 are partially delimited by the walls of a first helicoidal spiral 234 and of a second helicoidal spiral 236 which are intertwined around the pipe 29, as in the secondary embodiment variant illustrated in FIGS. 8 and 10, the inlet sealing means visible in FIG. 7 comprise the end face 251 of the heat exchanger 2, the cylindrical envelope 235 and a first spiral plug 225 which initiates the wall of the first spiral 234 and extends axially toward the end face 251, and a second spiral plug 227 which initiates the wall of the second spiral 236 and extends axially toward the end face 251. By being pressed against the end face 251 of the heat exchanger 2, the first and second spiral plugs 225 and 227 sealingly separate the respective inlets 221 and 223 of the first and second distribution chambers 231 and 233.

The first inlet 221 of the first distribution chamber 231 is thus delimited axially, for the one part, by a portion of the end face 251 comprising the aperture 222 corresponding to this first inlet 221, and, for the other part, by the second helicoidal spiral 236, radially, for the one part, by the cylindrical envelope 235, and, for the other part, by the pipe 29, and angularly by the second spiral plug 227 initiating the wall of the second spiral 236.

The first spiral plug 225 angularly prevents the first flow from joining the second distribution chamber 233 over the axial length of the first spiral plug 225, the first flow being forced, in this first inlet 221, to flow axially between the first spiral plug 225 and the wall of the second spiral 236, that is to say is forced to engage between a surface of the wall of the first spiral 234 and a surface of the wall of the second spiral 236, defining the first distribution chamber 231.

Similarly, the second inlet 223 of the second distribution chamber 233 is delimited axially, for the one part, by a portion of the end face 251 comprising the aperture 224 corresponding to this second inlet 223, and, for the other part, by the first helicoidal spiral 234, radially, for the one part, by the cylindrical envelope 235, and, for the other part, by the pipe 29, and angularly by the first spiral plug 225 initiating the wall of the first spiral 234.

The second spiral plug 227 angularly prevents the second flow from joining the first distribution chamber 231 over the axial length of the second spiral plug 227, the second flow being forced, in this second inlet 223, to flow axially between the second spiral plug 227 and the wall of the first spiral 234, that is to say is forced to engage between another surface of the wall of the second spiral 236 and another surface of the wall of the first spiral 234, defining the second distribution chamber 233.

In the section of part of the cooling device 1 shown in FIG. 8, illustrating this secondary embodiment variant of the invention with the connection block 30, the first and second flows of refrigerant fluid FR exiting the expansion valve 6 in order to respectively reach the first inlet 221 and the second inlet 223 of the intake orifice 22 are shown by arrows. Of course, this secondary embodiment variant is also usable with the connection block 3.

In this secondary embodiment variant of the invention, as in the main embodiment variant of the invention, one of the plates 254 of the bundle of plates forming the heat exchanger 2 that is situated between the first body 25 of the heat exchanger 2 and the second body 27 of the heat exchanger 2 tightly encloses the inlet manifold 23 in order to prevent the refrigerant fluid from passing from the first body 25 to the second body 27 outside the inlet manifold 23.

FIG. 9 now schematically describes the path of the refrigerant fluid and of a heat transfer liquid H2O in the heat exchanger 2.

The heat exchanger 2 is formed of a bundle of plates which are brazed together and between which channels are formed. The bundle of plates more specifically forms an alternation of channels that are intended for the refrigerant fluid FR and of channels that are intended for the heat transfer liquid H2O.

The refrigerant fluid FR and the heat transfer liquid H2O enter the heat exchanger 2 respectively via the inlet manifold 23 for refrigerant fluid of the heat exchanger 2 and the inlet 26 for heat transfer liquid H2O of the heat exchanger 2. The inlet manifold 23 comprises the intake orifice 22 for refrigerant fluid FR.

Passages between the plates allow the refrigerant fluid FR and the heat transfer liquid H2O to be discharged respectively via the discharge orifice 24 of the heat exchanger 2 and the outlet 28 for heat transfer liquid of the heat exchanger 2.

The bundle of plates of the heat exchanger 2 comprises:

• • a first plurality of plates 251, 252, 253, 254 between which first channels intended to receive the refrigerant fluid FR and defining the first body 25 of the heat exchanger 2 are arranged, and
  • a second plurality of plates 271, 272, 273, 274 between which second channels intended to receive the refrigerant fluid FR and defining the second body 27 of the heat exchanger 2, disposed on the opposite side from the intake orifice 22 with respect to the first body 25, are arranged, the distribution of refrigerant fluid FR being able to be managed independently in the first channels and the second channels.

For simplification in the FIGS. 9 and 10, the heat exchanger 2 comprises only two first channels and two second channels. Of course, the heat exchanger 2 according to the invention generally comprises a lot more first and second channels.

One first channel for refrigerant fluid FR is formed between the plates 251 and 252, and another first channel for refrigerant fluid FR is formed between the plates 253 and 254. In the first body 25 of the heat exchanger 2, one channel for heat transfer liquid is formed between the plates 252 and 253, and another channel for heat transfer liquid is formed between the plates 254 and 271.

One second channel for refrigerant fluid FR is formed between the plates 271 and 272, and another second channel for refrigerant fluid FR is formed between the plates 273 and 274. In the second body 27 of the heat exchanger 2, one channel for heat transfer liquid H 20 is formed between the plates 272 and 273, and another channel for heat transfer liquid is formed between the plate 274 and the end plate 211 of the heat exchanger 2 from which the discharge orifice 24 exits.

In each channel, the refrigerant fluid FR or the heat transfer liquid H2O is shown arriving in the channel by solid arrows and leaving again, after traveling in a U in the channel, by dashed arrows toward the discharge orifice 24 or the outlet 28 for heat transfer liquid H2O.

As explained above, in order to homogenize the distribution of refrigerant fluid FR in the heat exchanger 2, the refrigerant fluid FR at the outlet of the expansion member 6, or of the first and second expansion members 64, 62, is separated into two flows. The first flow is brought to the first inlet 221 of the intake orifice 22, serving the first distribution chamber 231 for distributing the first flow of refrigerant fluid FR in the first body 25 of the heat exchanger 2. The second flow is brought to the second inlet 223 of the intake orifice 22, serving the second distribution chamber 233 for distributing the second flow of refrigerant fluid FR in the second body 27 of the heat exchanger 2.

The first flow is distributed by the first distribution chamber 231 to the first channels sealingly with respect to the distribution of the second flow by the second distribution chamber 233 to the second channels. Thus, the inlet manifold 23 is capable of providing a first flow rate to the first channels and a second flow rate to the second channels, said flow rates being of substantially identical value, thus homogenizing the distribution of the refrigerant fluid FR in the heat exchanger 2. Depending on the cooling needs of the components of the vehicle, use is potentially made of only the first body of the heat exchanger or the second body of the heat exchanger 2. In this case, only the first flow or the second flow is sent to the heat exchanger 2.

In the main embodiment variant of the invention presented in this FIG. 9, the first distribution chamber 231 is formed by the walls of the angular cylindrical-sleeve portion 238 around the pipe 29, this angular cylindrical-sleeve portion 238 extending axially from the end face 251 of the heat exchanger 2 to an end of the first channels at the interface with the second body 27 of the heat exchanger 2, but not beyond that. The walls of the angular cylindrical-sleeve portion 238 are closed and sealed except for:

• • in contact with the end face 251 of the heat exchanger 2 so as to receive the refrigerant fluid FR from the first inlet 221 for refrigerant fluid FR of the heat exchanger 2, and
  • facing first channels; apertures 237 are arranged on the angular cylindrical-sleeve portion 238 facing first channels, such that the refrigerant fluid FR circulates from the first distribution chamber 231 to the first channels.

Notably, the base of the angular cylindrical-sleeve portion 238 situated between the first channels and the second channels forms a sealing barrier between the first channels and the second channels.

The second distribution chamber 233 is delimited by the cylindrical envelope 235 which is present all the way around the pipe 29, except for at the angular cylindrical-sleeve portion 238 which delimits the first distribution chamber 231. The cylindrical envelope 235 is sealed except for:

• • in contact with the end face 251 of the heat exchanger 2 so as to receive the refrigerant fluid FR from the second inlet 223 for refrigerant fluid FR of the heat exchanger 2, and
  • facing second channels; apertures 239 are arranged on this portion of the cylindrical envelope 235 such that the refrigerant fluid FR circulates from the second distribution chamber 233 to the second channels.

FIG. 10 illustrates the secondary embodiment variant of the invention, in which the distribution chambers 231 and 233 are each formed by a volume comprised between the walls of the first helicoidal spiral 234 and of the second helicoidal spiral 236 which are intertwined around the pipe 29. The spirals 234 and 236 extend radially in the inlets of the first and second channels. These spirals are preferably ribs which extend radially around the pipe 29 and are produced integrally with the pipe 29.

More specifically, the first helicoidal spiral 234 conducts the first flow from the first inlet 221 of the intake orifice 22 to first gaps between the first spiral 234 and the second spiral 236 that are situated facing first channels. Similarly, the second helicoidal spiral 236 conducts the second flow from the second inlet 223 of the intake orifice 22 to second gaps between the first spiral 234 and the second spiral 236 that are situated facing second channels. In this secondary embodiment variant of the invention, the first and second gaps are for example of identical width, in particular when the number of first channels is equal to the number of second channels.

In order to seal the first body 25 with respect to the second body 27 for the distribution of the refrigerant fluid FR, the inlet manifold 23 comprises a first sealing barrier 232 between the first distribution chamber 231 and the second body 27, said first sealing barrier being produced, in this embodiment variant of the invention, in the form of a spiral plug which is situated between the spirals 234 and 236 and blocks the passage of the first flow of refrigerant fluid FR. Thus, the first flow cannot reach the second channels.

The cylindrical envelope 235 forms a second sealing barrier 235 between the second distribution chamber 233 and the first body 25, said second sealing barrier tightly and sealingly enclosing the spirals 234 and 236. This cylindrical envelope 235 blocks the passage of the second flow into the first channels. Apertures 230 in the cylindrical envelope 235 nevertheless allow the first flow to pass into the first channels.

In this secondary embodiment variant of the invention, the cylindrical envelope 235 extends for example axially from the end face 251 of the heat exchanger 2 to an end of the first channels at the interface with the second body 27 of the heat exchanger 2, but not beyond that. If, on the contrary, the cylindrical envelope 235 extends axially from the end face 251 to the region of the second end 292 of the pipe 29 connected to the high-pressure outlet manifold 44 of the internal heat exchanger 4, then apertures similar to the apertures 239 are for example arranged in the cylindrical envelope 235 in order to allow the second flow to pass into the second channels. In this secondary embodiment variant of the invention, the cylindrical envelope 235 is, in a variant, replaced by a helicoidal envelope covering only the gap between the first helicoidal wall 234 and the second helicoidal wall 236 which delimits the second distribution chamber 233, and extending axially only from the end face 251 of the heat exchanger 2 to an end of the first channels at the interface with the second body 27 of the heat exchanger 2.

FIG. 11 now illustrates the use of the connection block 3 according to the invention and of the cooling device according to the invention, in a cooling system of an electric or hybrid vehicle. The vehicle comprises an electric battery 84, a power electronics unit 86 and an electric machine 82, these components being cooled by a circuit for heat transfer liquid H2O, for example water, the circulation of which is ensured by a pump 80. The heat transfer liquid H2O enters the heat exchanger 2 via the inlet 26 for heat transfer liquid, and emerges from the heat exchanger 2 via the outlet 28 for heat transfer liquid, having been cooled. This cooling is effected in contact with the refrigerant fluid FR also circulating in the heat exchanger 2, in a separate refrigerant fluid circuit.

The refrigerant fluid FR that has taken heat energy from the heat transfer liquid H2O exits the heat exchanger 2 at low pressure via the discharge orifice 24 of the heat exchanger 2, and is then sent to the high-pressure inlet manifold 46 of an internal heat exchanger 4, from which it emerges via the low-pressure outlet manifold 48 of the internal heat exchanger 4 in order to be sent to a compressor 7. This low-pressure branch for the refrigerant fluid FR in the internal heat exchanger 4 makes it possible to cool a high-pressure branch of the circuit for refrigerant fluid FR, as described below.

The refrigerant fluid FR compressed by the compressor 7 is then condensed by a condenser 9. Part of the condensed refrigerant fluid FR is directed to an expansion member 11 and then evaporated in an evaporator 5 of an air-conditioning system for the vehicle interior. Another part of the condensed refrigerant fluid FR is sent to the high-pressure inlet manifold 42 of the internal heat exchanger 4, and emerges from the internal heat exchanger 4 via the high-pressure outlet manifold 44 of the internal heat exchanger 4. This high-pressure branch of the circuit for refrigerant fluid FR is cooled in the internal heat exchanger 4 by the low-pressure branch of the circuit for refrigerant fluid mentioned above. The refrigerant fluid FR arriving from the high-pressure outlet manifold 44 is then expanded by the first and the second expansion member 64 and 62, and then enters the intake orifice 22 for refrigerant fluid of the heat exchanger 2, by passing through the connection block 3, in order to cool the heat transfer liquid H2O also passing through the heat exchanger 2.

Of course, the invention is not limited to the examples which have just been described, and numerous modifications may be made to these examples without departing from the scope of the invention.