EP2689205B1 - Connecting reinforcement for between the plates of a heat exchanger - Google Patents

Description

The invention relates to the field of heat exchangers between two fluids, in particular for cooling an air flow by heat exchange with a refrigerant.

The invention relates in particular to an exchanger according to the preamble of claim 1. Such an exchanger is known from the document JP 09113171 . Such heat exchangers are used in the field of air conditioning, for example motor vehicles and are in particular evaporators for a vehicle air conditioning loop. They make it possible to exchange heat between a first fluid, in particular air and a second fluid, for example a refrigerant fluid. They comprise a bundle of tubes, intended for the circulation of the second fluid, arranged in parallel on one or more rows, spacers of entry and / or exit of the second fluid into the tubes and spaces between the tubes for the circulation of the second fluid.

It is known from the document FR2929388A1 a heat exchanger whose tubes are manufactured by assembling a first plate and a second plate identical to each other, each having a concavity turned towards one another, and a peripheral edge assembled one to the other in a sealed manner, so as to create a fluid flow conduit, said tube, sealed to the refrigerant and allowing it to circulate there. Such exchangers therefore comprise a plurality of plates stacked from one side to the other side of the exchanger to form a tube bundle. Each tube has two ends and therefore each plate also has two ends.

Such tubes have, for example at their ends, a fluid distribution zone, also called collecting space, for collecting and distributing the coolant.

Each plate is thus provided with a stamp defining the fluid distribution zone in the exchanger and making it possible to establish a connection between two adjacent plates of two successive tubes. These connections ensure the stability of the structure, to ensure the seal between an internal volume of the heat exchanger and the surrounding environment, that is to say between the internal volume of the tubes and the air. They also allow the coolant to circulate in the exchanger from one tube to another.

Between their ends, the tubes have a central part, called tube body, guiding the refrigerant fluid from one end to the other.

Said tubes being in contact with each other only at their ends, there are spaces between the bodies of two adjacent tubes. These spaces are used to circulate the first fluid through the heat exchanger to exchange heat with the second fluid flowing inside the tubes.

The exchanger also comprises an inlet pipe carrying the cooling fluid to the tubes, connected to the tubes via an inlet spacer and an outlet pipe discharging the refrigerant from the tubes and connected thereto by the intermediate of an exit spacer.

In order to maximize the cooling capacity of the exchanger while reducing its mass, the document FR2929388A1 proposes a thickness of the plates forming the tubes less than 0.3 mm. A problem is created when said tubing or pipes are subjected to mechanical stresses related, for example, to the operation of the vehicle. These constraints are then reflected on the plates of the exchanger via the spacers. The plates being of thickness less than 0.3 mm, they deform under the effect of the stress, which can cause a rupture between two adjacent plates, thus creating a leak allowing the coolant to escape.

The aim of the invention is to remedy the aforementioned problem by proposing to improve the resistance to stresses at the level of the connections between two adjacent plates while retaining the use of plates less than 0.3 mm thick.

It proposes for this purpose a heat exchanger, comprising a plurality of stacked plates of thickness less than 0.3 mm, each provided with a male stamp defining a fluid distribution zone in the exchanger, at least a first plate and a second plate each comprise a peripheral edge sealingly assembled to form a fluid flow conduit.

According to the invention, the heat exchanger comprises at least one insert provided with a female stamp, the insert being secured to one of the plates, the male stamp of a plate adjacent to the plate integral with the insert being configured to penetrate the female insert of the insert to provide a connection between the plate integral with the insert and the adjacent plate, and therefore between two adjacent ducts or between a side plate and an adjacent duct

In other words, according to the invention, the heat exchanger has at least one insert, provided with a projecting edge configured to extend and surround the male stamp of an adjacent plate in order to increase the resistance to stress of the connection between the insert and the plate.

The multiplicity of plates extends over a width between a first side of the exchanger and a second side of the exchanger. The plates located on the sides of the exchanger are thus called "side plates".

According to one aspect of the invention, the insert is made from a first or second plate of a conduit.

According to one aspect of the invention, the insert is an insert on a first or second plate of a conduit or on a side plate.

and / or second plate, said edge extending in the extension of the tubular sector. It is understood here that the edge forms a cylindrical section coaxial with the tubular sector and of equivalent diameter. By covering the male stamp of one of the plates by the female stamping present on the insert, thus reinforcing the connection between the plate and the insert whatever the direction of the stresses on the link.

According to one aspect of the invention, the male stamp of the first and / or second plate, has a tubular sector terminated by a bottom which extends in a plane perpendicular to a central axis of the tubular sector. The bottom is, for example, provided with an opening through which the fluid passes. In this way, it is possible to define the path of the second fluid within the exchanger, by choosing a bottom provided or not with an opening.

According to one aspect of the invention, the multiplicity of plates comprises a fluid circulation portion interposed between two plate ends, the male stamping of the first and second plates being made at at least one end of said plates.

According to one aspect of the invention, the first and second plates defining a duct or the assembly formed of a plate of a duct and a side plate each comprise at one end both a stamped male and a stamped female. In this way, the reinforced connection between the plate and the insert is doubled and its strength is thus improved.

According to one aspect of the invention, each end of the plates comprises both a stamped male and a stamped female.

According to one aspect of the invention, the first twenty-five per cent of said width from one side of the exchanger are configured so that the male stamp of each plate enters the female stamp of each insert, in order to ensure interlocking between the plates. We understand that the exchanger is provided in this case with a plurality of inserts. The plates located in seventy-five percent remaining of said width then do not have such inserts. In this way, the zone of the exchanger, mainly subjected to the stresses transmitted by the inlet and / or outlet pipes of the refrigerant, that is to say the zone located near the inlet struts, is reinforced in particular. and / or output, themselves positioned at one side of the exchanger.

According to one aspect of the invention, the exchanger comprising a first side plate located at the first side of the exchanger and a second side plate located at the second side of the exchanger, the insert is installed against each of the side plates so that the female stamping of the insert covers the male stamp of the plate adjacent to the first side plate and the plate adjacent to the second side plate. It is understood here that such an exchanger comprises two inserts, each brazed to a side plate.

The first connections between a plate and an insert from the sides of the exchanger are thus reinforced, the side plates have for example a thickness of 1 mm, greater than the thickness of the other plates to increase the strength of the first link . In particular, the insert has a thickness greater than 0.3 mm.

• La figure 1 est une vue schématique en perspective d'un échangeur de chaleur.
• La figure 2 est une vue schématique partielle en plan d'un exemple de réalisation d'un évaporateur et d'une tubulure d'entrée de fluide réfrigérant.
• La figure 3 est une vue schématique partielle d'une liaison entre deux plaques adjacentes d'un évaporateur, conformément à l'invention.
• La figure 4 est une vue en perspective éclatée d'une partie de l'échangeur comprenant un insert selon l'invention.
• La figure 5 est une vue schématique en plan de deux plaques adjacentes d'un évaporateur.

The appended figures will make it clear how the invention can be realized. In these figures, identical references designate similar elements.

• The figure 1 is a schematic perspective view of a heat exchanger.
• The figure 2 is a partial schematic plan view of an exemplary embodiment of an evaporator and a refrigerant inlet manifold.
• The figure 3 is a partial schematic view of a connection between two adjacent plates of an evaporator according to the invention.
• The figure 4 is an exploded perspective view of a portion of the exchanger comprising an insert according to the invention.
• The figure 5 is a schematic plan view of two adjacent plates of an evaporator.

By convention and to simplify the description of the heat exchanger 1 according to the invention, a Cartesian coordinate system (x, y, z) is formed and the ox direction is defined as being the width of the exchanger, oy its depth, and oz its height. The directions o-x, o-y and o-z are parallel to the axes o-x, o-y and o-z respectively. The embodiment described below is an evaporator but it goes without saying that the invention also covers a condenser, a radiator or any other exchanger constituted according to claim 1 whatever the fluids passing through.

As can be seen on the figure 1 the heat exchanger or evaporator 1 comprises a stack of fluid flow duct, said tube 2. Each tube 2 comprises a first plate 3 and a second plate 4 formed from a metal sheet or strip, stamped shaped cups. The plates 3 and 4 are identical to each other and have their concavities facing each other in the ox direction. The first and second plates 3 and 4 each comprise a peripheral edge 25 assembled in a fluidtight manner, for example by brazing to form a tube 2 and delimiting an interior volume of the tube 2. Each of the plates is provided with a stamped male 8 delimiting a fluid distribution zone 6, 7 in the exchanger 1. This male embossed 8 is for example located at at least one end of each plate in the direction oz and in particular at the two ends of each plate according to the direction oz. In this way, a first plate 3 and a second plate 4 of the same tube 2 define a distribution zone of fluid 6, 7 in the exchanger at the ends of the tube 2 in the direction oz, that is to say according to its height. The fluid distribution zone situated at the level of the upper part of a tube 2 along the axis oz is called the upper distribution zone 6 while that located at the lower part of a tube 2 along the axis oz is called the lower distribution zone 7.

The tube 2 can thus be traversed by a fluid, said second fluid, in particular a refrigerant circulating in an air conditioning circuit of a motor vehicle when the heat exchanger 1 is an evaporator, a gas cooler or a condenser. It may also be a coolant circulating in a cooling circuit of a thermal or electric motor of a motor vehicle when the heat exchanger 1 is a radiator.

The fluid distribution zones 6, 7 occupy, for example, a minority fraction of the height of the tube 2 at the upper and lower portions thereof, the rest of the height of the tube 2 being occupied by one more body region. thin. A fluid circulation portion 19 is thus interposed between two fluid distribution zones, that is to say between two ends of the same plate. Thus, two adjacent tubes 2 are in contact at their fluid distribution zones, that is to say at the level of the male stamps 8 present on the adjacent plates belonging to two different tubes 2. A free space 13 located between two body regions of smaller thickness of two adjacent tubes 2 defines a path in the direction o-y for a first fluid, for example air to be cooled. Interlayers (not shown) are in particular installed in the free space 13, to increase the heat exchange between the outer walls of the tubes 2 and the air flow.

The sheet forming the plates 3 and 4 is, for example, an aluminum alloy and has a thickness less than 0.3 mm, preferably between 0.24 and 0.28 mm and in particular equal to 0.27 mm. An internal disturbance, zig-zag-shaped, (not shown) can be arranged between the plates 3 and 4 of a same tube 2 to promote heat exchange between the refrigerant and the inner wall of the tube 2.

The tube 2 may have a sealed junction zone 14, extended according to its height, that is to say in the direction oz, dividing the same tube 2 into a first half-tubes 2 'and a second half-tubes 2 " and thus allows the tube 2 to define two paths for the coolant The first half-tube 2 'of a tube 2 is located towards a front face 17 of the exchanger and the second half-tube 2 "of the same tube 2 is located towards a rear face 18 of the exchanger. The sealed junction zone thus extends from the upper distribution zone 6 to the lower distribution zone 7, at the mid-width of the tube 2 in the o-y direction. The sealed junction zone may or may not have a passage (not shown) at the region of distribution of the upper fluid 6 or the lower distribution zone 7, to let the fluid from the first half-tube 2 'to the second half -tube 2 "of the same tube 2, that is to say in the direction oy.

In addition, two so-called side plates 15, 16 are disposed on the sides of the exchanger in the direction ox and serve, in particular, to protect the last spacers of the exchanger located on each side of the heat exchanger 1. We call first side of the exchanger 1 the side located on the right side of the figure 1 and first plate 15, the plate located at the first side. In the same way, the second side 16 of the exchanger 1 is called the side located on the left side of the drawing and the second side plate 16 is the plate located on the second side.

Thus, from one side to another following the direction ox and from right to left on the figure 1 , the heat exchanger 1 is composed of the first side plate 15, bonded at a first connection with the first plate 3 of a first tube 2a, itself linked with the second plate 4 of the first tube 2a , itself in connection with the first plate 3 of a second tube 2b; a plurality of plates are then stacked in this manner to form N tubes, the second plate 4 of an N ^th tube being connected to the second side plate 16.

The heat exchanger 1 further comprises a fluid inlet spacer 11 and a fluid outlet spacer 12 disposed on an outer face of the first side plate 15 in the extension of the distribution zones of the upper fluid 6 and / or lower 7. The spacers 11 and 12 thus project relative to the first side plate 15 and may in particular have a tubular section whose central axis is directed in the ox direction. The spacers 11 and 12 may have different diameters.

The embodiment described by way of example in figure 1 , presents the fluid inlet spacer 11 and fluid outlet spacer 12 disposed on the side of the first side plate 15 of the heat exchanger 1. However, the present invention also covers any other arrangements of the spacers 11, 12 by report to exchanger 1.

The figure 2 illustrates in greater detail the zone of the heat exchanger 1 close to the inlet and outlet struts 11 (not shown in FIG. figure 2 ). It also makes it possible to represent an inlet pipe 20 connected to the inlet spacer 11 and allowing the fluid to enter the exchanger 1. On the other hand, an outlet pipe allows the refrigerant to exit the heat exchanger. heat but is not shown in the figures. These pipes are often subjected to constraints F related, for example, to the operation of the vehicle and transmit them through the inlet spacer 11 and outlet 12 to the exchanger 1.

Thus, the refrigerant liquid describes a path in the exchanger between the inlet spacer 11 and the outlet spacer 12 as a function of the presence or not of the openings 10 situated at the level of the zones of distribution of the fluid, between two half-tubes 2 or two half-tubes 2 "of two adjacent tubes 2 and the presence or absence of passages located at the junction zone 14 allowing the fluid to pass from one half-tube 2 'to the other half-tube 2' of the same tube 2, that is to say from one face to the other of the exchanger according to the direction oy.

The figure 3 illustrates an upper distribution zone 6, formed by the assembly of the first plate 3 of the first tube 2a and the second plate 4 of the first tube 2a. The figure 3 also illustrates an insert 5 according to the invention, in particular provided with a female stamping 9, and an inlet spacer 11 of the refrigerant and an inlet pipe 20 allowing the refrigerant to enter the exchanger 1. According to the invention, the male stamp 8 of the first and / or second plate (3, 4) is configured to penetrate into the female stamping 9 of the insert 5 to ensure their joining. In the example shown on the figure 3 the insert 5 is adjacent to the first plate 3 and covers the male stamp 8 of this plate. It is also located on an inner face of the first side plate 15 of the exchanger 1. The insert 5 thus defines a rigid connection means with the first plate 3, and delimits with the side plate 15 a manifold through which the coolant is able to flow.

Thus, when the inlet and / or outlet pipe 20 is subjected to stresses F, whatever their directions, which are transmitted to the exchanger at the level, in particular, of the reinforced connection between the first side plate 15 and the first plate 3 of the first tube 2a, the risk of rupture of the sheet or brazed connection is reduced. Correlatively, the reliability of the exchanger is increased.

The figure 4 allows to illustrate in more detail an insert 5 adapted to be attached to the first side plate 15. The insert 5 is here an insert, that is to say distinct from the plates before assembly and installed between them at the time of pre-assembly. It could also be attached to first plates 3, second plates 4 and / or on the second side plate 16. The insert 5 has a flat section 30, on the left side of the figure, intended to come into contact and be soldered against the first plate of side 15 against which the insert 5 is reported. The flat section 30 provides in this way the mechanical reinforcement which the insert 5 performs the function.

The flat section 30 comprises two lateral edges, a lower edge and an upper edge defining together the periphery of the insert 5. When the insert 5 is positioned in the exchanger, its depth corresponds to the depth of the plates, it is that is, the distance between its two lateral edges in the direction oy is equal to the depth of the plates in the direction oy. In contrast, the insert 5 is lower than the plates, that is to say that the distance between its upper edge and its lower edge is less important than the height of the plates in the direction o-z.

The insert 5 may, for example, be provided with a plurality of tongues 35, located on the periphery of the insert 5, perpendicular to the flat section 30 and able to be crimped or folded on the first side plate 15 on which the insert 5 is attached, to ensure its fixation. The tongues 35 allow in particular to ensure the pre-assembly of the insert 5 against the first side plate 15 before the soldering operation. The insert comprises for example four tabs 35, two of which are located on its upper edge and one on each of its lateral edges.

On the opposite side to the flat section 30, that is to say on the right side of the figure, are located two female stampings 9 intended to cover two male stampings 8 of the first plate 3, adjacent to the first plate 15 on which the insert 5 is attached. Male stampings 8 and 9 thus have a complementary shape allowing the interlocking of one (male 4) in the other (female 9). Although not shown, the insert 5 may also be provided with a female stamp 9 and a male stamp 4 in the case where the first 3 and the second 4 plates also have a male stamp 8 and a corresponding female stamp 9 .

According to a variant of the invention not shown, the insert 5 is made of a material of a plate and can be of a first plate 3, a second plate 4, a first plate of side 15 and / or a second side plate 16. It is in this case made of the same material as the plate from which it is derived, that is to say that it is made unitarily with the plate, forming with she a block of unique material. Such a configuration of the insert 5 is reflected on the plate on which it is located by, in particular, the presence of a shoulder at which the insert 5 starts, that is to say close to the end of the plate on which the insert 5 is located. In the case where the insert 5 is made of material of a plate, it has the same shape as that of the insert 5 attached to the plate as described above.

This form of the insert 5, whether added to or from a plate material, advantageously allows it to be placed between two adjacent plates of the exchanger, whatever their position among the multiplicity of plates.

Thus, according to another embodiment of the exchanger, two adjacent tubes 2, whatever their position in the exchanger 1, comprise a first plate 3 of one of the tubes 2 which is assembled with a second plate 4 of a other tubes via an insert 5. Therefore, one of the first and second plates 3, 4 comprises a 5 connecting insert so that the stamped male or female 8 or 9 of a tube is configured to penetrate or cover respectively the stamped female or male 9 or 8 of a tube 2 which is directly adjacent thereto.

According to a first variant embodiment, each of the links between the tubes 2 comprises an insert 5.

According to a second variant embodiment, some of the connections between the plates comprise an insert 5, for example certain connections situated at the level of the first twenty-five percent of the width of the exchanger 1, starting from the first side of the exchanger 1 , or only between the first and second side plates 15, 16 and their plates 3, 4 directly adjacent. Depending on the resistance to the stresses that we want to give the exchanger 1, we choose one or the other of these variants.

Still with the aim of reinforcing the structure, advantageously but not exclusively plates of sides 15, 16 of thickness approximately equal to 1 mm are chosen. And in the same way, inserts 5, thicknesses greater than 0.3 mm, are chosen, but it may be advantageous to choose an insert 5 of thickness identical to the thickness of the first and second plates 3, 4 constituting 'a tube.

The figure 3 further illustrates an aspect of the invention wherein the female stamping 9 of the insert 5 has a tubular sector 21 whose central axis is directed in the direction ox. It ends with an edge 22 extending in the extension of the tubular sector 21 and which covers the male embossed 8 of the first plate 3 of the first tube 2a. It is understood here that the edge 22 overlaps at least in part the male stamp 8. This edge 22 and this tubular sector forms a unitary unit. In practice, it is a tube of internal diameter or equal to the outer diameter of the male embossed 8.

This male stamp 8 of the first plate 3 or the second plate 4, also has a tubular sector 31 configured so that it can penetrate into the tubular sector 21 of the insert 5 but ending with a bottom 33 which extends in a plane perpendicular to a central axis of the tubular sector 21, that is to say in the direction ox. The bottom 33 is, for example, provided with an opening 10 through which the fluid passes. It is through these tubular sections 21 and 31 that the fluid will flow between two adjacent tubes 2 inside the exchanger 1.

According to another embodiment of the exchanger 1, each tube 2 is formed by a first half-tube 2 'and a second half-tube 2 ", separated from one of the other by the waterproof section. Each plate must be provided with two stampings delimiting the distribution zone 6, 7 of fluid in the exchanger 1.

As illustrated on the figure 5 and particularly advantageously, the first plate 3 and the second plate 4 have both a male stamp 8 and a female stamp 9, at least at one end of the plates, and in particular to both. In this way the fluid can circulate between the half-tubes 2 'of two adjacent tubes 2 and / or between the half-tubes 2 "of two adjacent tubes 2.

The figure 5 illustrates a first plate 3 and a second plate 4 belonging to two adjacent tubes 2 or a first plate 3 and a first side plate 15, shown here side by side. The first plate 3 located to the left of the figure 5 is stacked on the second plate 4 or on the first side plate 15 to the right of the figure by rotating 180 degrees about the axis A. In this way, when the two plates are stacked to form the exchanger 1, a stamped male 8 and a female stamped 9 of the insert 5 located at the end of a second plate 4 or a first plate 15, a stamped female 9 and a stamped male are matched 8 located at the corresponding end of the first plate 3 adjacent. This strengthens the connection between the two plates against the various constraints that can be exerted in the plane oyz. The advantage of such a structure lies in the fact that each plate is identical, that is to say embossed by the same press footprint. The logistics are thus reduced because one uses a single type of plate that is returned to achieve the first and second plate according to the invention. Each face of the exchanger is also reinforced, which makes it possible to provide a reinforcement according to the invention in a simple manner simultaneously to the two pipes, that is to say inlet and outlet pipes.

The heat exchangers according to the invention find a particular application in the heating, ventilation and / or air-conditioning installations of motor vehicles. It can also be cooling radiators of the engine, interior heating radiators, condensers, gas coolers or air conditioning system evaporators, charge air coolers and oil exchangers.

Claims (12)

1. Heat exchanger (1) comprising a multiplicity of stacked plates, each of which is provided with a male dished member (8) which delimits a fluid distribution zone (6, 7) in the exchanger (1), at least a first plate (3) and a second plate (4) each comprise a peripheral edge (25) which is assembled in a fluid-tight manner in order to form a fluid circulation pipe, characterized in that the plates have a thickness of less than 0.3 mm and in that it comprises at least one insert (5) which is provided with a female dished member (9), the insert being fixed to one of the plates (15, 3, 4), the male dished member (8) of a plate (3, 4) adjacent to the plate fixed to the insert (5) being configured to be introduced into the female dished member (9) of the insert (5) in order to ensure fixing between the plate fixed to the insert and the adjacent plate, and therefore between two adjacent pipes or between a side plate (15, 16) and an adjacent pipe.
2. Exchanger (1) according to Claim 1, wherein the insert (5) is integral with a first plate (3), a second plate (4) or a side plate (15, 16).
3. Exchanger (1) according to Claim 1, wherein the insert (5) is a component which is fitted to a first or second plate (3, 4) of a pipe or to a side plate (15, 16) .
4. Exchanger (1) according to Claim 2 or 3, wherein the female dished member (9) of the insert (5) has a tubular section (21) which terminates in an edge (22) which covers the male dished member (8) of a plate (3, 4) of an adjacent pipe, the edge (22) extending in continuation of the tubular section (21).
5. Exchanger (1) according to one of the preceding claims, wherein the male dished member (8) of a plate (3, 4) has a tubular section (31) which terminates in a base (33) which extends in a plane perpendicular to a centre axis of the tubular section (31).
6. Exchanger (1) according to Claim 5, wherein the base (33) is provided with an opening (10) through which the fluid passes.
7. Exchanger (1) according to one of the preceding claims, wherein the multiplicity of plates comprises a fluid circulation portion (19) which is interposed between two plate ends, the male dished member (8) being formed at least at one end of the plates.
8. Exchanger according to one of Claims 5 to 7, wherein the plates (3, 4) delimit a pipe or the assembly formed by a plate (3), a pipe and a side plate (15, 16) each comprise at least at one end both a male dished member (8) and a female dished member (9).
9. Exchanger (1) according to one of the preceding claims, wherein the first twenty-five percent of the width from one side of the exchanger is configured so that the male dished member (8) of each plate (3, 4) is introduced into the female dished member (9) of each insert (5) in order to ensure fixing between the plates (3, 4) .
10. Exchanger (1) according to Claim 9, comprising a first side plate (15) which is located in the region of a first side of the exchanger (1) and a second side plate (16) which is located in the region of a second side of the exchanger (1), wherein the insert (5) is installed against each of the side plates (15, 16) so that the female dished member (9) of the insert (5) covers the male dished member (8) of the plate adjacent to the first side plate (15) and the plate adjacent to the second side plate (16).
11. Exchanger (1) according to Claim 10, wherein the side plate (15, 16) has a thickness of 1 mm.
12. Exchanger (1) according to one of Claims 1 to 11, wherein the insert (5) has a thickness greater than 0.3 mm.

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