EP3394553A1

EP3394553A1 - Heat exchanger, in particular for a motor vehicle

Info

Publication number: EP3394553A1
Application number: EP16826392.9A
Authority: EP
Inventors: Anthony KOULANSKI
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2015-12-21
Filing date: 2016-12-16
Publication date: 2018-10-31
Anticipated expiration: 2036-12-16
Also published as: EP3394553B1; FR3045809B1; WO2017109355A1; FR3045809A1

Abstract

The invention relates to a heat exchanger, in particular for a motor vehicle, said exchanger including: a heat exchange core (3) with a plurality of heat exchange tubes defining circulation channels for a fluid in the heat exchange tubes; and at least one box for collecting (19) the fluid. According to the invention, the heat exchanger (1) also includes a flange for attachment (23) of the collection box (19), forming an interface between the collection box (19) and the heat exchange core (3), and the attachment flange (23) includes at least one surface (235) arranged opposite the collection box (19) and having a coating which is intended to melt during the brazing of the heat exchanger (1).

Description

Heat exchanger, in particular for a motor vehicle

The invention relates to the field of heat exchangers.

The invention relates more particularly to heat exchangers able to be traversed by a refrigerant fluid having a relatively high operating pressure, as is the case with natural gases such as carbon dioxide designated CO ₂ , having a pressure of superior operation to refrigerant gases used in state-of-the-art solutions.

Such heat exchangers find particular application in motor vehicles. They may in particular constitute a gas cooler in which the cooling fluid such as CO ₂ is cooled by a second fluid, such as liquid. Conversely, the second fluid can be cooled by the first fluid for example in gaseous form, the heat exchanger is then commonly referred to as "Water chiller" in English.

Such heat exchangers can in particular be used in the thermal regulation of one or more batteries of an electric or hybrid vehicle. The thermal regulation of the batteries is an important point because if the batteries are subjected to temperatures too cold, their autonomy can decrease strongly and if they are subjected to too high temperatures, there is a risk of thermal runaway up to to the destruction of the battery. In order to regulate the temperature of the batteries, it is known to use a coolant, generally coolant comprising a mixture of brine, which circulates in a heat exchanger in contact with the battery or batteries. The cooling liquid can thus bring heat to the battery or batteries to heat them, this heat having been absorbed by the cooling liquid for example during the heat exchange with the C0 ₂ flowing in the gas cooler. The coolant can also, if necessary, absorb the heat emitted by the battery or batteries to cool them and remove this heat at one or more other heat exchangers.

Such heat exchangers can also be used like any other gas cooler in an air conditioning circuit.

Heat exchangers are known, for example, comprising a stack of plates allowing the circulation of the first fluid, such as the refrigerant or refrigerant gas, and the second fluid such as the cooling liquid.

However, the use of a cooling fluid such as C0 ₂ under a very high pressure, generally greater than 100 bar, with a burst pressure which can reach, for example, up to 340 bar, implies that heat exchangers such as gas coolers can withstand such high pressures.

Plate heat exchangers known from the prior art do not allow to withstand such high pressures.

In order to remedy this, heat exchangers comprising a stack of tubes interconnected by at least one collector of the first fluid, in particular the refrigerant fluid on each side of the tubes, and the second fluid, for example, are known from the prior art. in liquid form, can circulate around the tubes in an envelope connected to a water box.

However, such an architecture is complex to achieve and has particular disadvantages in terms of sealing, particularly in the case of a brazed heat exchanger for which it proves necessary to provide a multiple soldering point for several pieces of the heat exchanger. In addition, with this architecture, the two fluids circulate generally cross flow, it is not always possible to provide a flow against the current or in several passes of the two fluids, which limits the efficiency of the exchanger thermal. In addition, it is difficult to reduce the tube height below 2mm due to the known design of the collector receiving the ends of the tubes, which also limits the efficiency of the heat exchanger. It has also been found that such a heat exchanger does not always have good mechanical strength.

In addition, in the case of heat exchangers assembled by brazing, in the solutions of the prior art it is generally necessary to provide a filler material such as a solder paste for the assembly of the collector or a fluid collection box on the heat exchange bundle. Moreover, a constant problem of heat exchangers implemented in a motor vehicle lies in the allocation of a reduced space, in order to meet the requirements of manufacturers.

The present invention aims to improve the solutions of the state of the art and to at least partially solve the disadvantages described above by providing a heat exchanger whose assembly, in particular by brazing, is improved.

For this purpose, the subject of the invention is a heat exchanger assembled by brazing, in particular for a motor vehicle, said exchanger comprising:

a heat exchange bundle with a plurality of heat exchange tubes defining circulation channels for a fluid in the heat exchange tubes, and

at least one manifold of the fluid.

According to the invention, the heat exchanger further comprises a fixing flange of the header forming an interface between the header and the heat exchange bundle. The fixing flange has at least one surface arranged facing the header and having a coating for melting during soldering of the heat exchanger.

The mounting flange allows simple assembly of the manifold to the heat exchange bundle.

In addition, the coating provided on the fastening flange capable of melting during soldering to ensure the joining of the elements, dispenses with the use of a filler material, such as a brazing paste, on the elements that are not suitable for use. inside the heat exchange bundle. In particular, it is not necessary to provide such a filler material on the faces facing the outside of the heat exchange bundle of the end elements of the heat exchange bundle in the stacking direction of the tubes. heat exchange.

The heat exchanger may further comprise one or more of the following features taken alone or in combination:

the fixing flange has a surface, said lower surface, opposite to at least one surface, said upper surface, arranged next to the box collector, said lower surface being intended to be soldered to the heat exchange bundle;

the manifold has a complementary shaped base of the fastening flange assembled on the fastening flange;

the fastening flange has a substantially "C" shaped profile with:

• a body and

Two ends substantially curved relative to said body and arranged on either side of said body, cooperating with two lateral flanges of the base of the manifold;

- The body of the fastening flange has the surface, said upper surface to be assembled by soldering to the manifold, and the opposite surface, said lower surface, to be assembled by soldering to the heat exchange bundle;

the fastening flange has a coating for melting upon soldering on the inner surface of both ends of the fastening flange;

the fixing flange is made in one piece with a frame, said end frame;

the fixing flange comprises means for placing in fluid communication between the manifold and the circulation channels for the fluid in the heat exchange tubes.

According to another aspect of the invention, the heat exchange bundle comprises at least one closure plate of the heat exchange bundle. The closure plate is arranged at the end of the heat exchange bundle in the stacking direction of the heat exchange tubes.

The closure plate has an end received between the attachment flange and the manifold.

According to one embodiment, the closure plate extends longitudinally substantially parallel to the heat exchange tubes and one of the longitudinal ends of the closure plate is received between the fixing flange and the manifold. Advantageously, the manifold has a recess forming receiving housing of the end of the closure plate.

Thus, only the coating provided inside the heat exchange bundle is used, without the need for additional filler material for brazing the header box on the heat exchange bundle, in particular on the closure plate of the bundle heat exchange.

According to yet another aspect of the invention, the heat exchanger allows for a heat exchange between at least a first fluid and a second fluid, and:

the heat exchange tubes define:

· First circulation channels for the first fluid to be dispensed by the header into the heat exchange tubes, and

Second circulation channels for the second fluid between the heat exchange tubes, and

said exchanger comprises an alternating stack of:

First receiving frames for the heat exchange tubes comprising means for placing fluid communication between the collector box of the first fluid and the first circulation channels for the first fluid of the heat exchange tubes, and

Second frames respectively defining a second circulation channel for the second fluid and respectively having means for fluidic communication between the second circulation channel and the inlet and outlet pipes for the second fluid. In the invention, the frames designate a part, or an assembly of parts, which can be rigid, delimiting a closed space or not. In this space can be positioned, in our example, heat exchange tubes.

It will be noted that the heat exchange bundle, which comprises a plurality of heat exchange tubes, is distinct from the first and second frames.

According to a particular embodiment, the closure plate extends over a length less than the length of the first and second frames.

The heat exchanger thus comprises a stack of simple elements, namely frames and heat exchange tubes in which the first fluid circulates, such as the refrigerant, inserted into the first frames and between which flows the second fluid such as coolant.

The superimposed frames make it possible to create the flow path of the first fluid such as a refrigerant, when the frames are brazed together, and likewise the superposed frames make it possible to create the flow path of the second fluid, such as coolant in particular on two opposite sides of the heat exchange bundle.

Such an architecture allows a simpler realization of the heat exchanger as a whole.

Finally, such a heat exchanger has a better mechanical strength compared to the solutions of the prior art and very good resistance to high pressures, in particular due to the circulation of CO ₂ as a refrigerant gas.

Other features and advantages of the invention will emerge more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which:

FIG. 1 is a perspective view of a heat exchanger,

FIG. 2 is a partial perspective view of a stack of first frames and second frames of the heat exchange bundle of the heat exchanger of FIG. 1;

FIG. 3 is another perspective view of a stack of first frames and second frames of a heat exchange bundle,

FIG. 4 is a partial perspective view of the heat exchanger of FIG. 1 showing in more detail a collecting box of a first fluid; FIG. 5 is a partial perspective view of the heat exchange bundle showing a fastening flange arranged above the stack of first and second frames, and

FIG. 6 is a cross-sectional view of the top of the heat exchanger showing the manifold of FIG. 4 and the fixing flange of FIG. 5. In these figures, substantially identical elements have the same references.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined to provide other embodiments.

In the present, the terms upper and lower, or high and low, or vertical and horizontal, are designated with reference to the arrangement of the elements in the figures. This arrangement corresponds to the inverted arrangement of the elements in the mounted state in a motor vehicle in particular.

Heat exchanger

With reference to FIG. 1, the invention relates to a heat exchanger 1, in particular for a motor vehicle, for a heat exchange between at least a first fluid and a second fluid. The first fluid can enter heat exchanger 1 in gaseous form and the second fluid in liquid form.

It is in particular a heat exchanger assembled by brazing. To do this, the heat exchanger 1 has at least partially, that is to say on at least some elements or parts, a coating intended to melt to ensure the joining of elements of the heat exchanger during the heat exchange. soldering assembly, as will be detailed later. Such a coating is commonly referred to as "clad" in English in the field of brazing metal parts, in particular aluminum.

The heat exchanger 1 according to the invention is particularly suitable for the circulation of at least one fluid having a high operating pressure, in particular greater than 100 bar.

For example, the first fluid is a refrigerant intended to circulate at high pressure such as C0 ₂ , also designated R744 according to the industrial nomenclature. The heat exchanger 1 can in particular be a gas cooler in which the cooling fluid such as CO ₂ is cooled by a second fluid for example in liquid form, such as cooling liquid comprising a mixture of brine.

The second fluid such as the coolant can also be cooled by the first fluid such as CO ₂ , such a heat exchanger is then commonly referred to as "Water chiller" in English.

The heat exchanger 1 comprises a heat exchange bundle 3 for heat exchange between the first fluid and the second fluid. In the illustrated example, the heat exchange bundle 3 has a generally parallelepipedal shape.

The circulation of the first and second fluids is advantageously countercurrent in the heat exchange bundle 3.

The introduction and the evacuation of the first fluid in the heat exchange bundle 3 or outside the heat exchange bundle 3 is shown schematically by way of example by the arrows Fli for the introduction and Fl ₀ for the evacuation.

Similarly, the introduction of the second fluid into the heat exchange bundle 3 and the evacuation of the second fluid out of the heat exchange bundle 3 is shown schematically by way of example by the arrows F2i for the introduction and F2 ₀ for evacuation.

Finally, the heat exchanger 1, and more precisely the heat exchange bundle 3, may be configured for circulation in at least two passes of one of the two fluids, or both fluids.

An example of circulation of the two fluids against the current and in two passes is illustrated schematically by the arrows F1 and F1 in FIG.

More precisely, the heat exchange bundle 3, better visible in FIGS. 2 and 3, comprises a plurality of heat exchange tubes 5 stacked so as to alternately define first channels (not visible in the figures) of circulation for the first fluid in the heat exchange tubes 5 and second circulation channels 9 for the second fluid between the exchange tubes thermal 5.

The heat exchange tubes 5 are preferably made by extrusion.

The heat exchange tubes 5 can be made in the form of flat tubes, advantageous in terms of space. The flat tubes 5 have a generally rectangular general shape, with a length for example of the order of 32 mm and a thickness of about one millimeter.

The thickness is here considered in the direction of the height of the heat exchange bundle 3, we can also speak of the height of the heat exchange tubes 5. In other words, it is the thickness in the direction of stacking heat exchange tubes 5.

Each heat exchange tube 5 defines a predetermined number of first channels (not visible in the figures) of circulation for the first fluid, in particular microchannels (not visible in the figures) of circulation for the first fluid. The first channels or micro-channels extend here substantially longitudinally in a substantially "I" or rectilinear form.

The first channels or microchannels (not visible in the figures) of circulation for the first fluid allowing the flow of the first fluid respectively extend in a direction parallel to the longitudinal direction of the heat exchange tubes 5.

The first fluid can follow a circulation in a so-called flow in

"I" but also a circulation in two passes known as "U" circulation as will be described later.

Similarly, the second circulation channels 9 for the second fluid may be shaped to allow circulation in a so-called "I" flow but also a circulation in two passes called "U" circulation as will be described later.

Turbulators 11 of the flow of the second fluid are advantageously arranged in the second circulation channels 9, thus improving the heat exchange between the two fluids.

The turbulators 11 may be carried by a separate element 12 of the tubes heat exchange 5 as illustrated in Figure 2. The turbulators 11 have for example a substantially crenellated form.

Interlayers are advantageously arranged between the heat exchange tubes 5, and define the pitch between the heat exchange tubes 5.

According to an advantageous embodiment, the heat exchange bundle 3 comprises an alternating stack of first frames 13 and second frames 15. At least some second frames 15 form the spacers. The stack is here substantially vertically.

Each first frame 13 is able to receive at least one heat exchange tube 5 and this assembly forms a stage of the heat exchange bundle 3. The first frames 13 can be designated by tube frames.

Each second frame 15 can receive turbulators 11 and this set forms another stage of the heat exchange bundle 3. These two sets or stages are repeated as many times as necessary depending on the space available and the performance to be achieved.

The first frames 13 and the second frames 15 are described in more detail below.

By way of example, closure plates 17, 18 (see FIG. 1), in particular at least one bottom closure plate 17 and at least one upper closure plate 18, can be arranged on either side of the wall. stacking the first frames 13 and the second frames 15, so as to close the heat exchange bundle 3.

The closure plate or plates 17, 18 are thus arranged at the end of the heat exchange bundle in the stacking direction of the heat exchange tubes 5, or in other words in the stacking direction of the first frames 13 and the second frames 15.

The closure plates 17, 18 advantageously have a shape complementary to the shape of the first frames 13 and the second frames 15.

Referring to Figures 1 and 4, the heat exchanger 1 further comprises at least one manifold 19 of the first fluid arranged in fluid communication with the first channels (not visible in the figures) of circulation. The collecting box 19 is according to the illustrated example arranged on an upper closure plate 18 disposed at the top of the heat exchange bundle 3.

Of course, according to a variant not illustrated, the manifold 19 can be arranged on the lower closure plate 17 disposed at the bottom of the heat exchange bundle 3.

The heat exchanger 1 further comprises at least two inlet and fluid outlet pipes 21 for introducing and evacuating the second fluid. In this example, the two tubes 21 are arranged on the same upper closure plate 18 as the manifold 19 for the first fluid.

Of course, according to a variant not illustrated, it is possible to arrange the two pipes 21 on the bottom closure plate 17.

According to yet another variant not illustrated, provision can be made to separately arrange the pipes 21 with a pipe 21 on the upper closure plate 18 and the other pipe 21 on the lower closure plate 17.

In particular, the manifold 19 can be arranged on one side of the heat exchange bundle 3 and the tubes 21 can be arranged on the other side of the heat exchange bundle 3, thus allowing a counter-current circulation of two fluids. According to the arrangement illustrated in Figure 1, the manifold 19 is arranged on the left while the pipes 21 are arranged on the right.

First frames called tubes-frames

Regarding the first frames 13, better visible in Figure 2, they can be at least partially made of aluminum.

The first frames 13 present:

two opposite edges extending perpendicular to the direction of the first flow channels of the first fluid, in other words here perpendicular to the longitudinal direction of the heat exchange tubes 5, and

two other opposite edges extending parallel to the direction of the first flow channels of the first fluid, in other words here in parallel with the longitudinal direction of the heat exchange tubes 5.

It is also possible to define the first frames 13 with respect to the general direction of flow of the first fluid, namely that the first frames 13 have:

two opposite edges extending perpendicularly to the general direction of flow of the first fluid, and

two other opposite edges extending parallel to the general direction of flow of the first fluid.

The general direction of flow of the first fluid means the direction of the flow in "I" in the case of a flow in one pass of the first fluid, or the direction of the branches of the "U" in the case of a circulation in two passes of the first fluid.

In the example shown, the first frames 13 are of generally rectangular shape and have two longitudinal edges forming long sides, extending substantially parallel to the general direction of flow of the first fluid and two side edges forming small sides, extending in the width direction, substantially perpendicular to the direction of flow of the first fluid. Only a lateral edge of a first frame 13 is visible in FIG.

The longitudinal axis of the first frames 13 and heat exchange tubes 5 is here confused.

However, according to other embodiments, it is possible to provide second frames having a general shape that is not rectangular, for example elliptical, or diamond-shaped.

These first frames 13 may have the same thickness as the heat exchange tubes 5 they receive, in particular of the order of a few millimeters, for example of the order of 1mm.

The thickness is considered in the direction of the height of the heat exchange bundle 3, we can also speak of the height of the first frames 13. This is the thickness in the stacking direction of the frames 13, 15.

Thus, the heat exchange tubes 5 can be maintained in the first respective frames 13 before superposition of the various frames 13, 15. Each first frame 13 may receive a heat exchange tube 5 or alternatively at least two heat exchange tubes 5, so that the heat exchange bundle 3 then has at least two rows of heat exchange tubes.

In addition, to allow circulation in at least two passes of the first fluid, two adjacent heat exchange tubes 5 arranged in a first frame 13 can communicate with each other at one end.

Moreover, in order to allow the flow of the first fluid in the heat exchange bundle 3, the first frames 13 comprise means for placing in fluid communication 131 the first circulation channels of the first fluid with the manifold 19.

The fluid communication means 131 of each first frame 13 are advantageously arranged in fluid communication with the fluidic communication means 131 of the other first frames 13 of the heat exchange bundle 3 and with the manifold 19.

The fluid communication means 131 provided on the first frames 13 make it possible, in a simple manner, to collect the first fluid and to distribute it, for example, in the heat exchange tubes 5 held in these first frames 13. no longer necessary to provide the collectors on each side of the tubes as in the known solutions.

According to the example illustrated in FIG. 2, the first frames 13 respectively have a predefined number of recesses 131 forming the fluidic communication connection means, in which the ends, in particular the longitudinal ends, of the heat exchange tubes 5 open out. .

Of course, the number of recesses 131 is adapted according to the number of first circulation channels of the heat exchange tubes 5.

These recesses 131 are advantageously provided on two opposite edges of the first frames 13 which are facing the ends of the heat exchange tubes 5. These are the lateral edges of the first frames 13.

The first frames 13 are arranged so that their recesses 131 are in fluid communication with the recesses 131 of the other first frames 13. recesses 131 of the first frames 13 are aligned in the direction of the height of the heat exchange bundle 3.

In addition, with reference to Figures 1 and 2, on one side of the first frames 13, the recesses 131 are aligned with the manifold 19.

According to one embodiment, at least one side edge of a first receiving frame 13, arranged opposite one end of a heat exchange tube 5, is shaped according to a pattern defining a succession of arches.

The arches are advantageously arranged over the entire width of the lateral edge which is opposite one or more ends of tube (s) heat exchange 5. In other words, the arches are provided over the entire width of the set of tubes heat exchange 5 that the first frame 13 can receive, here two heat exchange tubes 5.

Arch is understood to mean the group formed by an arch arch 132 connecting two feet of arch 133. In this series of arches, two adjacent arch arches 132 are connected by a common arch foot 133.

According to the illustrated example, a recess 131 is delimited by an arch, in other words each recess 131 is made between two adjacent arch feet 133 and is delimited by these two arches 133 and the arch arch 132 connecting them .

When a heat exchange tube 5 is arranged in a first frame 13, the space remaining between one end of the heat exchange tube 5 and an arch arch 132 defines a through opening of fluid communication.

The arches are sized taking into account the mechanical strength of the first frame 13 and the flow of the first fluid through the recesses 131 defined by the arches.

In addition, in the case of a heat exchanger 1 assembled by soldering, the arches 133 still make it possible to define soldering zones with the second frames 15.

Furthermore, in order to allow the flow of the second fluid in the heat exchange bundle 3, the first frames 13 also have guides 134 for the passage of the second fluid. According to the illustrated example, the first frames 13 are respectively shaped with at least one loop 134 which when at least one heat exchange tube 5 is arranged in the first frame 13 defines a through opening for the flow of the second fluid.

The handles 134 allow to define the guides for the passage of the second fluid. The loops 134 of each first frame 13 are arranged in alignment with the handles 134 of the other first frames 13 of the heat exchange bundle 3 so as to allow the flow of the second fluid through the heat exchange bundle 3.

By way of illustration, the figures show various embodiments of the loops 134, in particular FIG. 1 illustrates a first embodiment of loops 134 of substantially rounded shape, while FIGS. 2 and 3 illustrate a second exemplary embodiment. handles 134 whose contour is more rectilinear shape. Of course, any other form of the handles 134 may be considered.

In addition, each first receiving frame 13 may have at least one partition wall 135 which compartmentalizes the first receiving frame 13. This partition wall 135 is here arranged in the extension of an arch foot 133.

According to the particular example described, the partition wall 135 extends longitudinally substantially parallel to the direction of the first channels (not visible in the figures) of circulation for the first fluid in the heat exchange tubes 5.

More precisely, the partition wall 135 extends in this example substantially parallel to the longitudinal edges of the first frame 13.

In the example illustrated in FIG. 2, each first receiving frame 13 has a partition wall 135, for example a substantially central partition, which partitions the first reception frame 13 into two housings each for receiving a heat exchange tube 5.

The partition wall 135 is thus arranged between two heat exchange tubes 5 when they are placed in the first frame 13. The partition wall 135 extends in this example over the entire length of the exchange tubes thermal 5 received in the first frame 13. The partition wall 135 of a first frame 13 can be made in one piece with this first frame 13. Such a first frame 13 can be made by cutting stamping in a simple manner. Second frames

With reference to FIG. 3, the second frames 15 are now described.

The second frames 15 may be at least partially made of aluminum.

When the second frames 15 receive turbulators 11, the second frames 15 are said frames-turbulators or turbulators frames.

Similarly to the first frames 13, the second frames 15 have: two opposite edges extending parallel to the direction of the first channels (not visible in the figures) of circulation of the first fluid in the heat exchange tubes 5, in other words here parallel to the longitudinal direction of the heat exchange tubes 5, and

two other opposite edges extending perpendicular to the direction of the first channels (not visible in the figures) of circulation of the first fluid in the heat exchange tubes 5, in other words here perpendicularly to the longitudinal direction of the exchange tubes thermal 5.

It is also possible to define the second frames 15 with respect to the general direction of flow of the first fluid, namely that the second frames 15 have:

two opposite edges extending parallel to the general direction of flow of the first fluid, and

two other opposite edges extending perpendicular to the general direction of flow of the first fluid.

In addition, according to the embodiment described, it is still possible to define the second frames 15 with respect to the general direction of flow of the second fluid flowing against the current of the first fluid, namely that the second frames 15 have:

- two opposite edges extending parallel to the general direction of flow the second fluid, and

two other opposite edges extending perpendicular to the general direction of flow of the second fluid.

The general direction of flow of the second fluid means the direction of the circulation in "I" in the case of a circulation in a pass of the second fluid, or the direction of the branches of the "U" in the case of a circulation in two passes of the second fluid.

In the illustrated example, the second frames 15 are of generally similar shape to the first frames 13, here substantially rectangular.

The second frames 15 have two longitudinal edges, forming long sides, extending substantially parallel to the longitudinal edges of the first frames 13 and the general direction of flow of the second fluid, and two lateral edges, forming short sides, extending in the width direction, substantially perpendicular to the direction of flow of the second fluid parallel to the side edges of the first frames 13.

Likewise, according to other embodiments, it would be possible to provide first frames having a general shape that is not rectangular, for example elliptical, or diamond-shaped.

According to the embodiment described, the second frames 15 extend over the same length and the same width as the first frames 13. In particular, the outer contours of the first frames 13 and second frames 15 are substantially identical so that the alternating stacking of the first frames 13 and second frames 15 form a block.

More particularly, each second frame 15 defines an internal width and an internal length.

By "internal width" is meant the width defined between the inner walls of the opposite longitudinal edges. Similarly, the term "internal length", the length defined between the inner walls of the opposite side edges.

In addition, the lateral edges of the second frames 15 may be slightly larger than the lateral edges of the first frames 13, so that the ends heat exchange tubes 5 received in the first frames 13 stacked with the second frames 15, rest on the peripheral edge of the lateral edges of the second frames 15.

The second frames 15 thus define an internal length less than the internal length defined by the interior space of the first frames 13.

The second frames 15 have a thickness which is of the order of a few millimeters, for example of the order of 0.5mm to 4mm, preferably of the order of 2mm. The thickness is here considered in the direction of the height of the heat exchange bundle 3, we can also speak of the height of the second frames 15. In other words, it is the thickness in the stacking direction of the frames 13, 15.

Similarly to the first frames 13, the second frames 15 can be made by stamping cut.

A plurality of second so-called interposed frames 15 are arranged between two first frames 13 for receiving the heat exchange tubes 5, thus defining the pitch between two stages of heat exchange tubes 5.

According to a non-limiting embodiment, the heat exchange bundle 3 may furthermore comprise a second end frame optionally arranged between a first frame 13 and a closure plate, in particular the bottom closure plate 17. second end frame can be put in place for reasons of mechanical strength.

Of course, it is advantageous to provide a stack of first frames 13 and second frames 15 without such an end frame.

According to the embodiment illustrated in FIG. 3, the second frames allow a two-pass circulation of the second fluid. For this purpose, the second frames 15 each comprise a bar 150 arranged inside the second frame 15 so as to separate two flow passes for the second fluid.

It is therefore an internal bar 150. In the example illustrated, the bar 150 makes it possible to shape the second circulation channel 9 substantially in a "U" shape.

Of course, one could predict a circulation of the second fluid in addition to two passes in a second frame 15 and for this purpose more than one bar 150 inside the second frame 15 which would be, by way of non-limiting example, arranged in a staggered and opposite manner with respect to the other.

The strip 150 extends longitudinally inside a second frame 15. The strip 150 therefore extends in this example substantially parallel to the longitudinal edges of the second frame 15.

To do this, the bar 150 does not extend over the entire internal length of the second frame 15. In other words, the bar 150 extends from a side edge of a second frame 15 towards the opposite side edge but without reaching this opposite side edge.

The bar 150 is secured to a lateral edge of a second frame 15 and projects with its free end towards the internal space of the second frame 15 towards the opposite side edge, leaving a space.

The inner bar 150 thus extends longitudinally from a lateral edge of a second frame 15 over a length less than the internal length of the second frame 15.

The inner bar 150 does not extend over the entire internal width of the second frame 15. More specifically, the inner bar 150 has a width smaller than the internal width of the second frame 15.

The width of the inner bar 150 may be greater than or equal to, preferably greater than, the thickness of the second frame 15. Thus, on each side of the bar 150, the inlet and outlet of the flow path for the second fluid. The bar 150 may also be called tongue. In addition, the bar 150 is substantially of the same thickness as the second frame 15.

The bar 150 is for example arranged substantially centrally. More specifically, the bar 150 is arranged substantially in the center of a second frame 15 in the width direction of the second frame 15. In this way, the bar 150 divides the second frame 15 into two parts of the same size.

Advantageously, the inner bar 150 extends over a length at least equal to half the internal length of a second frame 15. According to the variant embodiment illustrated with reference to FIGS. 2 and 3, the inner bars 150 of the second frames 15 are opposite partitions 135 of first frames 13.

Of course, any other means for conforming the second circulation channel 9 in several passes can be envisaged, for example according to a non-illustrated variant such a means can be provided on a perturbation plate 12 carrying the turbulators 11 of the flow of the second fluid.

In a manner complementary to the first frames 13, the second frames 15, in particular the second intermediate frames 15, have guides 151 for the passage of the first fluid allowing it to flow in the stack of the first reception frames 13 and the second frames 15, especially spacers.

The guides 151 are here made in the form of through-passage orifices 151 arranged in alignment with the recesses 131 forming fluid communication with the first reception frames 13, delimited here by the succession of arches. The through orifices 151 are thus arranged on at least one lateral edge of a second frame 15, here a second intermediate frame 15.

Of course, the number of throughthrough orifices 151 is adapted as a function of the number of recesses 131 and thus the number of first circulation channels of the heat exchange tubes 5.

In addition, the second frames 15 respectively have means for fluid communication 152 of the second circulation channels 9 between them on the one hand and with the pipes 21 for the second fluid on the other hand.

Fluidic communication means 152 provided on the second frames make it possible to collect the second fluid and distribute it between the heat exchange tubes.

According to the example illustrated in FIG. 3, the second frames 15 respectively have a predefined number of through-openings 152, here two through-openings 152, of fluid communication.

The through openings 152 are here arranged on the longitudinal edges of the second frames 15 and are aligned with each other in the direction of the height of the heat exchange bundle 3, in other words in the stacking direction of the various frames 13, 15.

The through openings 152 open respectively to the inside of a second frame 15.

In addition, the through openings 152 are arranged on the same side of a second frame 15 in the longitudinal direction, that is to say right or left, complementary to the arrangement of the tubes 21 on a same side of the heat exchange bundle 3, here to the right with reference to the arrangement shown in FIG.

The through openings 152 define a fluid inlet 152 to the inner space of the second frame 15 on a longitudinal edge, and a fluid outlet 152 out of the second frame 15 on the opposite longitudinal edge.

More specifically, according to the illustrated example, the second frames 15 have handles 153 which define the through openings 152. The handles 153 of the second frames 15 are made similarly to the handles 134 of the first frames 13 and are aligned with these 134 handles that allow the passage of the second fluid through the heat exchange bundle 3.

As an illustration, the figures show different embodiments of the handles 153, in particular, Figure 1 illustrates a first embodiment of the loops 153 of substantially rounded shape, while Figure 3 illustrates a second embodiment of the handles 153 whose contour is more rectilinear shape.

Of course, when the loops 134 of the first frames 13 are made according to the first embodiment, the loops 153 of the second frames 15 are made similarly according to the first embodiment.

And when the handles 134 of the first frames 13 are made according to the second embodiment, the handles 153 of the second frames 15 are made similarly according to the second embodiment. Of course, any other form of the handles 153 may be considered.

Among the two loops 153 of the second frames 15, the opening defined by a first loop is arranged in fluid communication with a first pipe 21 and the opening defined by a second loop is arranged in communication fluidic with a second pipe 21.

As said above, the heat exchanger 1 is preferably assembled by brazing. The second frames 15 are intended to be soldered to the first frames 13.

In particular, the longitudinal edges of the second frames 15 are intended to be assembled by soldering to the longitudinal edges of the first frames 13 and the lateral edges of the second frames 15 are intended to be assembled by soldering with the arches 133 provided on the edges of the first frames 13.

Furthermore, the second frames 15, in particular the second intermediate frames 15, may also be shaped to put in fluidic communication two heat exchange tubes 5 received in the same first frame 13 as illustrated in FIGS. 2 and 3.

It is therefore the second frames 15 which allow the circulation in at least two passes of the first fluid in each first frame 13, while ensuring a good mechanical strength of the first frames 13 due to the C0 ₂ under high pressure circulating in the tubes. heat exchange 5.

More specifically, each second frame 15, in particular the spacer, advantageously has at least one overturning orifice 155 (see FIG. 3) which is in fluid communication with both a first and a second fluid communication means 131, here a first and a second recess 131, first frames 13 on either side of the second spacer frame.

Thus, each overturning orifice 155 is arranged between two adjacent heat exchange tubes 5 received in a first frame 13 and in fluid communication with these two heat exchange tubes 5. In this way, the first fluid that emerges from a first heat exchange tube 5 undergoes a reversal in the overturning orifice 155 and then flows to a second heat exchange tube 5.

The two rows of heat exchange tubes 5 arranged in the first frames 13 then communicate at one end via the overturning orifices 155 provided on the second frames 15, in particular spacers.

Each turning orifice 155 is here formed between passage orifices 151 through at least one side edge of each second frame 15, including interlayers.

Each overturning orifice 155 advantageously has a longitudinal shape extending substantially perpendicular to the general direction of flow of the first fluid in the two heat exchange tubes 5.

In this example, each overturning orifice 155 has a longitudinal shape extending perpendicularly to the longitudinal edges of the second frame 15, especially intermediate.

In particular, each turning orifice 155 arranged opposite a first receiving frame 13, extends longitudinally on either side of the partition wall 135 of this first receiving frame 13. By way of example, the turning orifice 155 has a substantially oblong shape.

Furthermore, the turning orifice 155 is dimensioned so as to have a section for the overturning of the first fluid at least equal to the passage section of a heat exchange tube 5.

Furthermore, preferably, a two-pass circulation, referred to as a "U" circulation, of the first fluid in a first reception frame 13 and a two-pass circulation, called a "U" circulation of the second fluid in a second 15. The heat exchanger 1 is then double "U" circulation.

Collecting box

With reference to FIGS. 1 and 4 to 6, the manifold box 19 for the first fluid and its assembly on the heat exchange bundle 3 are described in more detail.

The same manifold 19 can be compartmentalized, so as to define firstly the introduction of the first fluid schematized by the arrow Fli in Figure 1 and secondly the evacuation of the first fluid schematized by the arrow Flo on the figure 1.

According to a preferred embodiment, the heat exchanger 1 comprises an attachment flange 23 of the manifold 19 forming an interface between the manifold 19 and the heat exchange bundle 3. Due to its interface position, the fastening flange 23 comprises fluid communication means 231, such as fluidic communication connection holes 231, between the manifold 19 and the first channels (not visible in the figures ) of circulation defined by the heat exchange tubes 5, and therefore between the manifold 19 and the recesses 131 of the first frames 13 and the through holes 151 provided on the second frames 15, in particular on the second intermediate frames.

In addition, as can be seen more clearly in FIGS. 5 and 6, the fastening flange 23 has at least one surface 233, called the lower surface, arranged facing the manifold 19.

Said lower surface 233 is preferably intended to be soldered to the heat exchange bundle 3.

The fastening flange 23 has at least one surface 235 arranged facing the manifold 19, preferably intended to be assembled by soldering to the manifold 19.

Said lower surface 233 is opposed to at least one surface 235, referred to as the upper surface, arranged facing the manifold 19.

Advantageously, a form-fit is provided between the manifold 19 and the fastening flange 23.

In particular, the manifold 19 has a base 191 of complementary shape of the fastening flange 23 and it is this base 191 which is assembled on the fastening flange 23.

The base 191 of the manifold box 19 more precisely has a surface, for example substantially flat, in contact with the fastening flange 23 when the heat exchanger 1 is assembled.

According to the particular embodiment illustrated in FIGS. 4 to 6, the fastening flange 23 has a profile of substantially "C" shape with:

a body presenting in the illustrated example

The surface, called the lower surface, 233 intended to be assembled, preferably by soldering, to the heat exchange bundle 3, and The so-called upper surface 235 opposite said lower surface 233, said upper surface 235 is for example substantially planar and able to cooperate with the surface facing the base 191 of the header box 19 which is for example substantially flat, and

two ends 237 substantially curved with respect to the body 233, 235 of the fixing flange 23 and arranged on either side of the body 233, 235.

The two ends 237 of the fastening flange 23 are able to cooperate with two lateral flanges 192 of the base 191 of the manifold 19 as can be seen in FIG. 4.

The fastening flange 23, which is inside the heat exchanger 1 when assembled, advantageously has a coating, at least on said upper surface 235 opposite the manifold 19, this coating, as said previously is commonly referred to as "cladd" in the field of brazing metal parts, including aluminum.

According to the illustrated example, the fastening flange 23 also has such a coating on the inner surface of the ends 237 which come into contact with the manifold 19 for assembly.

By "inner surface" is meant the surface of each end 237 which is arranged in contact with a lateral cheek 192 of the base 191 of the manifold 19 when the manifold 19 is assembled on the fastening flange 23.

The inner surfaces of the two ends 237 face each other when the manifold 19 is not yet assembled with the fastening flange 23.

Of course, the fastening flange 23 may also have such a coating on said lower surface 233 which is therefore located inside the heat exchange bundle 3.

In other words, the fastening flange 23 has:

a face, said lower face, assembled, preferably by soldering, to the heat exchange bundle 3, and

a face, said upper face, opposite said lower face and assembled, preferably by brazing, to the manifold 19. Said lower surface 233 of the body of the fastening flange 23 forms said lower face assembled preferably by soldering to the heat exchange bundle 3. Similarly, said upper surface 235 of the body of the fastening flange 23 and the inner surface of the ends 237 of the fastening flange 23 form said upper face preferably assembled by brazing to the manifold 19.

The manifold 19 as for it does not need to present such a coating and can be made of aluminum without coating or cladd.

The manifold 19 may be mechanically joined to the fastening flange 23, for example by crimping, prior to soldering to ensure contact between said upper surface 235 of the fastening flange 23 having the coating and the lower surface of the manifold 19 .

During brazing, this assembly is pressurized and then passed to the oven and is heated, for example to a temperature of about 580 ° C. to 590 ° C., and the coating present on the fastening flange 23 melts, thus ensuring the connection between the fastening flange 23 and the manifold 19.

Indeed, the molten coating fills the spaces or interstices present between the surfaces of the fastening flange 23 and the manifold 19. The hardening of the molten coating (by cooling) ensures a tight connection without additional supply material.

In addition, the fastening flange 23 may have such a coating on said lower surface 233 facing a first frame 13 or alternatively facing a second frame 15.

Moreover, according to a particular non-limiting embodiment illustrated in FIGS. 4 to 6, the fastening flange 23 may be made in one piece with a frame 25, referred to as an end frame 25.

According to the particular example described, the end frame 25 is arranged at the end of the heat exchange bundle 3 in the stacking direction of the first frames 13 and second frames 15.

The end frame 25 is, for example, shaped substantially similar to a second intermediate frame as previously described. The fastening flange 23 then forms a lateral edge of this end frame 25 extending substantially perpendicularly to the general flow direction of the first fluid in the heat exchange tubes 5 (not visible in these FIGS. 4 to 6). . In this example, with a single manifold 19 on one side of the heat exchanger 1, the side edge of the end frame 25 which is opposite the fastening flange 23 does not have through orifices for the passage of the first fluid.

Similarly to the fastening flange 23, the end frame 25 also advantageously has a coating called "clad", at least on its upper face. The end frame 25 may also have on its underside facing a first frame 13, or alternatively a second frame 15, such a coating for assembly by soldering.

In addition, as previously said heat exchange bundle 3 may comprise at least one closure plate, in particular an upper closure plate 18. In particular, the upper closure plate 18 may have at least one through orifice (not visible) arranged in communication with a pipe 21.

The passage openings delimited by the handles 134 of the first frames 13 and the through openings 152 delimited by the handles 153 of the second frames 15 are arranged in fluid communication with the or orifice or orifices through (not visible) of this plate upper closure 18.

In order to allow the assembly of the at least one closure plate 18 and of the manifold 19, in this example above the heat exchange bundle 3, the closure plate 18 or the closure plates present ) an end received between the fixing flange 23 and the manifold 19, as is best seen in Figure 6.

According to the illustrated embodiment, the closure plate 18 extends longitudinally substantially parallel to the heat exchange tubes 5 or in other words parallel to the first frames 13 and second frames 15 in this example, and one of the longitudinal ends of the closure plate 18 is received between the fastening flange 23 and the manifold 19. In the example illustrated, on the lower side, that is to say on the side facing the stack of the heat exchange bundle 3, the end of the closure plate 18 is in contact with the fastening flange. 23, and here the peripheral edge of the closure plate 18 is also in contact with the end frame 25 made in one piece with the fastening flange 23 in this example.

In a complementary manner, the manifold 19 has a recess 193 forming a receptacle for receiving the end of the closing plate (s) 18. Thus, the closure plate 18, or the closure plates, extends ( ent) along a length less than the length of the first frames 13 and the second frames 15 and possibly the length of the assembly formed by the fastening flange 23 and the end frame 25 made in one piece.

The closure plate 18 which is above the whole assembly, therefore at the top of the heat exchange bundle 3, does not have a so-called clad coating at least on its face, here its upper face, which gives Outside of the heat exchanger 1. This closure plate 18, in the example illustrated at the top of the heat exchange bundle 3, can therefore be made only of aluminum.

It is possible to provide the presence of coating only between the lower face of the closure plate 18 which is inside the heat exchange bundle 3 and the element arranged below this closure plate 18, for example here the fastening flange 23 and the possible end frame 25.

The assembly of this closure plate 18 to the rest of the heat exchanger 1 is made possible due to the presence of the coating on the fastening flange 23, and possibly the end frame 25, on which or on which there is has a coating, so that during the passage in the oven, for example at a temperature of the order of 580 ° C-590 ° C, the coating melts and the connection is formed between the fastening flange 23 possibly made of a single piece with the end frame 25, and both the closure plate 18 and the manifold 19.

Thus, it proves unnecessary to provide additional material or material in addition to the coating already provided on the fastening flange 23 and the possible end frame 25. This part 23, 25 may have a coating in so far as she is located inside the heat exchanger 1.

This solution therefore makes it possible to avoid using, in addition, an additional filler material, such as solder paste, in order to be able to assemble the manifold 19 on the heat exchange bundle 3.

The above description provides an arrangement of the fastening flange 23 and the manifold 19 at the top of the heat exchange bundle 3 with reference to the arrangement illustrated in the figures. Of course, the invention also applies for an arrangement of the fastening flange 23 and the manifold 19 at the bottom of the heat exchange bundle 3.

In this case, the manifold 19, the lower closure plate 17 this time and the fastening flange 23 are arranged and assembled as described above with reference to the description of the arrangement and the assembly of the fastening flange. 23, the manifold 19 and the upper closure plate 18.

In this case, the bottom closure plate 17 does not have a so-called clad coating at least on its face, in this case lower, which gives on the outside of the heat exchanger 1, while allowing the assembly of the box manifold 19 on this underside of the closure plate 17.

The assembly of a heat exchanger 1 as defined above therefore comprises a step of arranging one or more heat exchange tubes 5 in a first frame 13 as described above.

A stage of the heat exchange bundle 3 is thus formed for the circulation of the first fluid in the first channels (not visible in the figures) for circulation of the heat exchange tubes 5.

The assembly may comprise a step of arranging turbulators 11 in a second frame 15 as defined above.

The second frame 15, receiving or not turbulators 11, forms another stage of the heat exchange bundle 3 for the circulation of the second fluid in the second circulation channels 9 between the heat exchange tubes 5.

The assembly further comprises a step of stacking a first frame 13 and a second frame 15. This is repeated as many times as necessary depending on the place available and required performance. The stack is here substantially vertically.

The assembly also comprises the arrangement of a lower closure plate 17 at the bottom of the heat exchange bundle 3. Of course, the order of these steps can be reversed.

For example, the bottom closure plate 17 may be firstly arranged and stacked over the first 13 and second frames.

Advantageously, a fixing flange 23 as described above is provided, which can be made in one piece with an end frame 25, above the stack of first frames 13 and second frames 15.

Of course, alternatively, the fixing flange 23 as described above, which can be made in one piece with an end frame 25, can be arranged below the stack of first frames 13 and second frames 15.

The assembly further comprises the arrangement of one or more upper closure plates 18 at the top of the heat exchange bundle 3.

At least one closure plate is at least partially in contact with the fastening flange 23 and the end frame 25, if any.

In the example described, an upper closure plate 18 is arranged at least partially in contact with the fastening flange 23 and the possible end frame 25.

Alternatively, a lower closure plate 18 may be arranged at least partially in contact with the fastening flange 23 and any end frame 25.

At least one manifold 19 is arranged for the first fluid on the fastening flange 23.

A step of mechanical assembly, for example by crimping, of the manifold 19 on the fastening flange 23 can be provided.

And, it arranges the inlet and outlet pipes 21 for the second fluid. Finally, the assembly can be brazed thanks to the presence of the coating capable of melting during soldering, only on the parts inside the heat exchange bundle 3.

The design of the fastening flange 23 as described above having such a coating, allows the particular assembly of the last part of the heat exchange bundle 3, in particular a closure plate of the heat exchange bundle 3, here the plate upper closure 18, and the manifold 19 arranged on this top closure plate 18.

Thus, it is unnecessary to use an additional element reported, such as a solder paste or a solder sheet.

Claims

1. heat exchanger (1) assembled by soldering, in particular for a motor vehicle, said exchanger (1) comprising:

a heat exchange bundle (3) with a plurality of heat exchange tubes (5) defining circulation channels for a fluid in the heat exchange tubes (5), and

at least one manifold (19) of the fluid,

characterized in that

the heat exchanger (1) further comprises a fastening flange (23) for the manifold (19) forming an interface between the manifold (19) and the heat exchange bundle (3), and in that

- The fixing flange (23) has at least one surface (235) arranged facing the manifold (19) and having a coating for melting during brazing of the heat exchanger (1).

2. Heat exchanger (1) according to the preceding claim, wherein the fastening flange (23) has a surface (233), said lower surface, opposite to at least one surface (235), said upper surface, arranged next to the header (19), said bottom surface (233) being intended to be soldered to the heat exchange bundle (3).

3. Heat exchanger (1) according to any one of the preceding claims, wherein the manifold (19) has a base (191) of complementary shape of the fastening flange (23) assembled on the fastening flange (23). .

4. Heat exchanger (1) according to the preceding claim, wherein the fastening flange (23) has a profile in profile substantially at "C" with:

a body (233, 235), and

two ends (237) substantially curved with respect to said body (233, 235) and arranged on either side of said body (233, 235), cooperating with two lateral cheeks (192) of the base (191) of the manifold (19).

Heat exchanger (1) according to any one of the preceding claims, wherein the fastening flange (23) is formed in one piece with a frame (25), said end frame.

Heat exchanger (1) according to any one of the preceding claims, wherein the fastening flange (23) comprises means for placing in fluid communication (231) between the manifold (19) and the circulation channels for the fluid in the heat exchange tubes (5).

Heat exchanger (1) according to any one of the preceding claims, wherein:

the heat exchange bundle comprises at least one closure plate (18) of the heat exchange bundle (3) arranged at the end of the heat exchange bundle in the stacking direction of the heat exchange tubes (5) , and

said at least one closure plate (18) has an end received between the fixing flange (23) and the manifold (19).

Heat exchanger (1) according to the preceding claim, wherein the manifold (19) has a recess (193) forming receiving housing of the end of the closure plate (18).

Heat exchanger (1) for a heat exchange between at least a first fluid and a second fluid, according to any one of the preceding claims,

in which the heat exchange tubes (5) define first circulation channels for the first fluid, intended to be distributed by the header (19), in the heat exchange tubes (5), and second channels circulation (9) for the second fluid between the exchange tubes thermal (5), and

said exchanger (1) comprises an alternating stack of:

First frames (13) for receiving the heat exchange tubes (5) comprising fluidic communication means (131) between the manifold (19) of the first fluid and the first circulation channels for the first fluid of the tubes heat exchange (5), and

Second frames (15) respectively defining a second circulation channel (9) for the second fluid and respectively having fluidic communication means (152) between the second circulation channel (9) and the inlet and outlet pipes; outlet (21) for the second fluid.

10. Heat exchanger (1) according to one of claims 7 or 8 taken in combination with claim 9, wherein the closure plate (18) extends along a length less than the length of the first (13) and second (15) frames.