EP2810013B1 - Heat exchanger - Google Patents

Description

The field of the invention is that of heat exchangers used in a motor vehicle. More particularly, the invention relates to an exchanger between a refrigerant fluid and a heat transfer fluid, with a view to cooling the latter.

A heat exchanger used in a motor vehicle generally comprises a plurality of chambers stacked in a longitudinal direction to form a heat exchange bundle. More specifically, among these chambers, a plurality of first chambers is intended to be traversed by the first fluid, while a plurality of second chambers is intended to be traversed by the second fluid. The set of first and second chambers then forms the heat exchange bundle, that is to say an area of the heat exchanger where the fluids are brought together to promote the transfer of calories from one fluid towards each other.

In order to delimit these chambers, it is already known to stack plates, so that the first chambers, capable of containing the first fluid, are each delimited by a pair of first plates, and the second chambers, capable of containing the second fluid, are each delimited by a pair of second plates. Among these plates, there is generally a circulation plate and two closure plates. Each of the circulation plates, interposed between two closure plates, is mainly pierced at its center, in order to accommodate at least one chamber, preferably two chambers. Thus, each of the chambers of the exchanger is delimited, axially, by the drilling of the circulation plate which is associated with it, and, longitudinally, by the two closure plates surrounding said circulation plate.

In addition, it is already known to provide orifices in the first and second plates, at their ends situated on either side of the chamber which they delimit. Thus, each plate comprises two "primary" orifices in communication with the corresponding chamber, for the circulation of the corresponding fluid inside the latter, as well as two "secondary" orifices. The secondary orifices of the first plates are intended to be in communication with the secondary orifices of the second plates, and vice versa.

During the manufacture of the exchanger, the first and second plates are stacked on top of each other, in the longitudinal direction. To this end, it is known to weld these plates together, according to a brazing process.

For example, documents WO 00/46564 , US4249597 , US2010 / 0258285 , US5042577 and WO 91/18253 disclose such plate exchangers.

However, because of the large number of first and second plates, the number of solder joints is necessarily high, which creates the risk of leakage.

The object of the invention is to reduce the number of solder joints, while promoting satisfactory heat exchange between the heat transfer fluid and the refrigerant fluid.

Another object of the invention is to reduce the weight and the cost of a heat exchanger, with a view to industrialization.

To this end, according to the invention, the heat exchanger intended to perform a heat exchange between a first fluid and a second fluid, comprising a plurality of chambers stacked in a longitudinal direction to form a heat exchange bundle, at least a first chamber capable of containing the first fluid being delimited by a pair of first plates, at least one second chamber capable of containing the second fluid being delimited by a pair of second plates, the second plates comprising orifices in communication with the second chamber , the first plates each comprising at least two primary orifices and at least two secondary orifices, the two primary orifices being in communication with the first chamber, the two secondary orifices being in communication with the orifices of the second plates, is remarkable by the fact that the first plates are distinct from the second plates, that each plate comprises a deformation delimited at the periphery by an edge, the bottom of the deformation extending in a plane distinct from that in which the peripheral edge extends, so as to delimit at least in part the corresponding chamber, that the deformation comprises a groove arranged so as to share the corresponding chamber in order to form a circuit for circulation of the fluid in "U" shape, and that all the chambers are arranged to delimit a circuit for circulation of the fluid in "U" shape, a first circuit in "U" being inverted with respect to a second "U" circuit, the second plates each comprising only two orifices, these second plates having no orifice in communication with the first chamber.

Thus, thanks to the present invention, the number of plates necessary for the delimitation, both axial and longitudinal, is reduced. In fact, in order to delimit for example a first chamber, it suffices to weld together only a pair of first plates, while the previous embodiments required at least three (a circulation plate and two closure plates). Similarly, to delimit a first chamber and then a second chamber, the invention makes it possible to limit the number of plates necessary to four (a pair of first plates and a pair of second plates), whereas previous embodiments required at least five (two circulation plates and three closing plates stacked alternately). By reducing the number of plates, the invention therefore also makes it possible to reduce the number of solder joints between the plates and therefore limits the risks of leakage in the heat exchange bundle.

It will be noted that, since the chambers are delimited longitudinally, the present invention allows a completely satisfactory heat exchange between the heat transfer fluid and the refrigerant fluid when the latter pass through said chambers.

It will also be noted that, to the extent that the present invention makes it possible to reduce the number of plates required, this also makes it possible to reduce the weight, as well as the cost of the heat exchanger, in the perspective of industrialization.

In order to limit the number of orifices necessary for assembling the plates, the second plates each comprise only two orifices. In such a case, these second plates have no orifice in communication with the first chamber.

The first plates are distinct from the second plates, which makes it possible to distinguish the chambers delimited by these plates, a part of the chambers being able to contain the first fluid, while the other part of the chambers is able to contain the second fluid. In addition, the heat exchange bundle thus produced is modular.

As regards the first plates, their primary and secondary orifices can be formed respectively at two longitudinal ends (5A, 5B) thereof, which makes it possible to provide the chambers at the center of these plates.

With regard to the second plates, their orifices are advantageously provided at a longitudinal end thereof.

The second plates having fewer holes than the first plates for the assembly of the heat exchange bundle, it can be expected that the length of the first plates is greater than that of the second plates.

Preferably, one of the first plates is attached to one of the second plates. Thus, apart from the brazing joint which mechanically connects these directly adjacent plates, the passage of air between them is avoided, which makes it possible to exclude the air / fluid exchangers.

Furthermore, each plate comprises a deformation delimited at the periphery by an edge, the bottom of the deformation extending in a plane distinct from that in which the peripheral edge extends, so as to at least partially delimit the corresponding chamber.

The deformation comprises a groove arranged so as to share the corresponding chamber in order to form a fluid circulation circuit in "U" shape.

In addition, all the chambers are arranged to delimit a “U” fluid circulation circuit, a first “U” circuit being reversed with respect to a second “U” circuit.

Advantageously, a disturbance is arranged inside at least one chamber. This disturbance has the function of disturbing the flow of fluids, in order to maximize the heat exchange between said fluids.

Likewise, to promote heat exchange between the fluids, the first chambers, capable of containing the first fluid, and the second chambers, capable of containing the second fluid, can be stacked, in the longitudinal direction mentioned above, by alternately.

In order to convey the first fluid to each of the first chambers capable of containing the first fluid, the latter are arranged to communicate with a connection device capable of putting said first chambers into communication with an external circuit.

In order to route the second fluid to each of the second chambers capable of containing the second fluid, the latter are arranged to communicate with a connection device arranged at one end of the bundle, in the longitudinal direction.

The present invention also relates to a heat exchange assembly comprising a heat exchanger according to one of the embodiments described above, as well as an expansion member secured to the heat exchanger.

In this assembly, the expansion member may include a solenoid valve.

The present invention also relates to a thermal conditioning system comprising a coolant circuit and a coolant circuit, at the confluence which is installed a heat exchanger according to one of the embodiments described above.

• La figure 1 est une vue en perspective éclatée d'un échangeur de chaleur selon l'invention.
• La figure 2 est une vue en perspective de l'une des plaques primaires de l'échangeur de la figure 1, associée avec deux chambres primaires.
• La figure 3 est une vue en perspective de l'une des plaques secondaires de l'échangeur de la figure 1, associée avec deux chambres secondaires.
• La figure 4 est une vue en perspective d'un ensemble d'échange thermique comprenant l'échangeur de chaleur de la figure 1.

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

• The figure 1 is an exploded perspective view of a heat exchanger according to the invention.
• The figure 2 is a perspective view of one of the primary plates of the exchanger of the figure 1 , associated with two primary chambers.
• The figure 3 is a perspective view of one of the secondary plates of the exchanger of the figure 1 , associated with two secondary bedrooms.
• The figure 4 is a perspective view of a heat exchange assembly comprising the heat exchanger of the figure 1 .

The figure 1 illustrates an embodiment of the heat exchanger 1 according to the invention. This heat exchanger is intended to implement a heat transfer between a first fluid and a second fluid. According to an exemplary embodiment, the first fluid can be a liquid, for example a heat transfer fluid such as glycol water, while the second fluid can be gaseous, two-phase or liquid.

In the embodiment of the figure 1 , the heat exchanger is more particularly intended to carry out a heat exchange between a refrigerant fluid FR, for example carbon dioxide, R134a or HFO1234YF, and a heat transfer fluid FC such as water with glycol added.

The heat exchanger 1 comprises a plurality of chambers 3 and 6 stacked in a longitudinal direction AA 'to form a heat exchange bundle 2, between a first end 2A and a second end 2B of said bundle 2, the second end 2B being opposite the first end 2A with respect to the heat exchange bundle 2. Part of the chambers 3, which can be described as “first chambers”, is intended to be traversed by the first fluid FC, while the other part of the chambers 6, which can be described as "second chambers", is intended to be traversed by the second FR fluid.

According to an exemplary embodiment, the heat exchanger 1 comprises alternating first chambers 3 and second chambers 6.

The set of first chambers 3 and second chambers 6 forms the heat exchange bundle 2, that is to say a zone of the heat exchanger 1 where the fluids FC and FR are brought together one of the to promote the transfer of calories from one to the other.

Each of the first chambers 3 is delimited by a pair of first plates 4 and 5. Likewise, each of the second chambers 6 is delimited by a pair of second plates 7 and 8. For this purpose, as can be seen on the figure 2 , a first plate 5, of the pair of first plates 4 and 5, comprises a deformation 55 delimited by a peripheral edge 56, the bottom of the deformation 55 extending in a plane distinct from that in which the peripheral edge extends 56. The other first plate 4, of the pair of first plates 4 and 5, (which is not shown), comprises a deformation similar to the deformation 55. The chamber 3 is thus delimited, on each side, by the deformations in the first plates 4 and 5.

The same applies to the second plates 7 and 8. Thus, as can be observed on the figure 3 , a second plate 8, of the pair of second plates 7 and 8, comprises a deformation 83 delimited by a peripheral edge 84, the bottom of the deformation 83 extending in a plane distinct from that in which the peripheral edge extends 84. The other second plate 8, of the pair of second plates 7 and 8 (which is not shown), comprises a deformation similar to the deformation 83. The chamber 6 is thus delimited, on each side, by the deformations formed in the second plates 7 and 8 of the same pair.

Furthermore, the deformation of each first plate, such as the first plate 5 of the figure 2 , comprises a groove 58 disposed at the center of said deformation 55, so as to share the first chamber 3. This groove 58 does not, however, extend along the whole of deformation 55, which makes it possible to provide, in the first chamber 3, two deformed portions 31 and 32 which are separated by the groove 58 and which communicate with each other via the third deformed portion 33. It is thus formed, by the portions 31 to 33 of the first chamber 3, a “U” fluid circulation circuit.

Similarly, in each second plate, such as the second plate 8, the deformation 83 is provided with a groove 85 arranged so as to delimit two deformed portions 61 and 62 separated by said groove 85 and which communicate with each other via a third deformed portion 63. It is thus also formed, by the portions 61 to 63 of the second chamber 6, a circuit for circulation of the fluid in "U" shape.

As shown in the figure 1 , each of the chambers 3 and 6 of the bundle 2 being arranged to delimit a circuit of the fluid in "U", said chambers 3 and 6 are arranged with respect to each other so that the circuit in "U" of each first chamber 3 either reversed with respect to the U-shaped circuit of each second chamber 6. As indicated on the figure 4 , the fluids FC and FR can thus circulate in "U", respectively in the first and second chambers, in identical directions, so that the circulation of one of the fluids is co-current with respect to the other of the fluids . However, it is possible, depending on an inversion of the direction of circulation of one of the FC or FR fluids relative to the embodiment of the figure 4 , that the fluids FC and FR circulate in opposite directions, so that the circulation of one of the fluids is against the current with respect to the other of the fluids, which makes it possible to promote the heat exchanges between them .

In this exemplary embodiment, in the volume delimited by each first chamber 3 and each second chamber 6 is housed a disturbance 9, the function of which is to disturb the circulation of the flow of the fluid inside the corresponding chamber, to favor the 'heat exchange. According to an exemplary embodiment, this disturber 9 is a corrugated sheet.

The first plates 4 and 5 each comprise two primary orifices 41, 42 and 51, 52, as well as two secondary orifices 43, 44 and 53, 54. The second plates are, in turn, each provided with only two orifices 71, 72 and 81, 82 able to extend on the side of the secondary orifices of the first plates.

The orifices of the first plate 5 are, as seen on the figure 2 , arranged in pairs at each of the two longitudinal ends 5A and 5B of said first plate 5. Thus, the pair of primary orifices 51, 52 is arranged on the side 5A intended to communicate with the connection device 20, so that these orifices are in communication with the first chamber 3. The pair of secondary orifices 53, 54, for its part, is arranged on the side 5B by which these can communicate with the orifices of the second plates.

The pair of orifices 81, 82 of the second plate 8 are, as seen on the figure 3 , disposed at a longitudinal end 8B of said second plate, on the side by which said orifices can communicate, on the one hand, with the second chambers 6, and, on the other hand, with the secondary orifices of the first plates 4 and 5. A the other longitudinal end 8A of the plate 8, however, there is made absolutely no orifice of any of the aforementioned types, the second plates 7 and 8 being, on the side of this end 8A, shorter than the first plates 4 and 5. It is therefore understood that the second plates 7 and 8 each comprise only two orifices.

Furthermore, the first and second plates are stacked on each other, in the longitudinal direction A-A ', so that the primary orifices 41, 42 and 51, 52 of all the first plates communicate together, in said direction A -AT'.

Furthermore, the first and second plates are stacked one on the other, in the longitudinal direction A-A ', so that the secondary orifices of the first and second plates communicate together, in said direction A-A', as well as with each of the second bedrooms 6.

The first plates being distinct from the second plates, the stacking can be obtained by joining the adjacent plates by brazing.

Thus, each chamber 3 or 6 is only delimited by two plates, which makes it possible to limit the number of solder joints to be made in order to assemble the heat exchange bundle 2, for a reduction in the risk of leaks, as well as reduced weight and cost. It will also be noted that the arrangement of only two orifices in the second plates 7 and 8 makes it possible to reduce the dimensions of these, compared to the first plates 4 and 5, and makes it possible to limit all the more the surface on which must be solder joints.

In one embodiment of the invention, the primary orifices 41, 42 and 51, 52 of the first plates 4 and 5 are delimited by tubes made of material, which have a height greater than the height of the tubes delimiting the secondary orifices 71 , 72 and 81, 82. In addition, the height of the pipes delimiting the secondary orifices 43, 44 and 53, 54 of the first plates 4 and 5 is substantially identical to the height of the pipes delimiting the orifices 71, 72 and 81, 82 of the second plates 7 and 8. The pipes of the primary orifices 41, 42 and 51, 52 of the first plates 4 and 5 preferably have a height which is substantially equal to twice the height of the pipes of the secondary orifices 43, 44 and 53, 54 of the first plates 4 and 5 or of the orifices 71, 72 and 81, 82 of the second plates 7 and 8.

On the side of the second end 2B, the last 5C of the first plates 5, is similar to a first plate 5, but has the particularity of being full. In fact and contrary to the first plates 4 and 5, which have at each of their ends at least one orifice 41, 42, 43, 44, 51, 52, 53 or 54 authorizing the circulation of the first fluid, the last first plate 5C devoid such orifices.

It will be noted that the last first plate 5C can form a base which receives a fixing means, the function of which is to ensure the mechanical maintenance of the heat exchanger 1 relative to a support external to the exchanger, for example the vehicle body or a mounting lug connecting the heat exchanger 1 to the vehicle.

The first chambers 3 are in communication, or in relation, with a circuit external to the heat exchanger 1, by means of a connection device 20. The function of this connection device 20 is to implement the circulation of the first fluid FC between at least one of the first chambers 3 of the heat exchanger 1 and the external circuit.

According to the example of the figure 1 , the connection device 20 is installed at the first longitudinal end 2A of the heat exchanger 1. This connection device 20 comprises two pipes 21 and 22 each comprising a reinforcing collar. Between the first plate 4 (on the side of the first end 2A of the bundle 2) and each tube 21 or 22, there is a bead forming an extra thickness of material which is intended to reinforce the brazing zone between the tubes and the first plate 4 .

In the heat exchanger according to the invention, the second chambers 6 are placed in communication with a second external circuit, for example a refrigerant circuit, by means of a connection device 10 arranged at a first end 2A of the bundle 2. This connection device 10 comprises two tubular orifices 11 and 12, intended to communicate with the second chambers 6 to allow the circulation of the second FR fluid therein.

We will now describe a heat exchange assembly 30 according to the present invention. This assembly includes the heat exchanger 1 as detailed above, to which is added a expansion member 40 secured to the exchanger, more particularly to the connection device 10. Advantageously, the connection device comprises a means for measuring the temperature of the refrigerant, which by way of example is a temperature probe . The expansion member 40 is one of the essential components for the operation of the thermodynamic cycle which takes place in the refrigerant circuit with which the heat exchanger 1 cooperates. This expansion member 40 lowers the pressure of the refrigerant before entering the secondary chambers. Such a reduction results in a cooling of the first fluid which circulates in the first chambers.

According to an optional variant of the heat exchange assembly 30, the expansion member 40 is provided with a solenoid valve 45 capable of electrically controlling said expansion member. Thus, the level of pressure reduction operated by the expansion member 40 can be placed under the dependence of an external control device which acts on the solenoid valve 45.

The present invention can advantageously be implemented in order to produce a thermal conditioning system. This system can include a first refrigerant fluid circuit FR and a second heat transfer fluid circuit FC, at the confluence of which is installed a heat exchanger as detailed above.

Claims (12)

1. Heat exchanger (1) intended for carrying out an exchange of heat between a first fluid (FC) and a second fluid (FR), comprising a plurality of chambers (3, 6) stacked in a longitudinal direction (A-A') to form a heat exchange core (2), at least one first chamber (3) able to contain the first fluid (FC) being delimited by a pair of first plates (4, 5), at least one second chamber (6) able to contain the second fluid (FR) being delimited by a pair of second plates (7, 8), the second plates (7, 8) comprising orifices (71, 72, 81, 82) in communication with the second chamber (6), the first plates (4, 5) each comprising at least two primary orifices (41, 42, 51, 52) and at least two second orifices (43, 44, 53, 54), the two primary orifices (41, 42, 51, 52) being in communication with the first chamber (3), the two secondary orifices (43, 44, 53, 54) being in communication with the orifices (71, 72, 81, 82) of the second plates (7, 8), characterized in that the first plates (4, 5) are distinct from the second plates (7, 8), in that each plate (4, 5, 7, 8) comprises a deformation (55, 83) delimited peripherally by an edge (56, 84), the bottom of the deformation (55, 83) extending in a plane different from that in which the peripheral edge (56) extends, so as to at least partially delimit the corresponding chamber (3, 6), in that the deformation (55) comprises a groove (58) arranged so as to divide the corresponding chamber (3) in order to form a U-shaped circuit (31, 32, 33) for circulation of the fluid (FC, FR), and in that all of the chambers (3, 6) are arranged so as to delimit a U-shaped circuit for circulation of the fluid (FC, FR), a first U-shaped circuit (31, 32, 33) being inverted relative to a second U-shaped circuit (61, 62, 63), the second plates (7, 8) each comprising only two orifices (71, 72, 81, 82), these second plates (7, 8) having no orifice in communication with the first chamber (3).
2. Heat exchanger according to Claim 1, in which the primary orifices (41, 42, 51, 52) and secondary orifices (43, 44, 53, 54) of the first plates (4, 5) are respectively created at two longitudinal ends (5A, 5B) thereof.
3. Heat exchanger according to either of Claims 1 and 2, in which the orifices (71, 72, 81, 82) of the second plates (7, 8) are created at a longitudinal end (8A, 8B) thereof.
4. Heat exchanger according to one of the preceding claims, in which the length of the first plates (4, 5) is greater than that of the second plates (7, 8).
5. Heat exchanger according to one of the preceding claims, in which one (5) of the first plates is placed in close contact with one (7) of the second plates.
6. Heat exchanger according to one of the preceding claims, in which a perturbator (9) is arranged inside at least one chamber (3, 6).
7. Heat exchanger according to one of the preceding claims, in which the first chambers (3) able to contain the first fluid (FC) and the second chambers (6) able to contain the second fluid (FR) are stacked in alternate fashion in the longitudinal direction (A) .
8. Heat exchanger according to one of the preceding claims, in which the first chambers (3) able to contain the first fluid (FC) are arranged so as to communicate with a connection device (20) that is able to establish a communication between said first chambers (3) and an external circuit.
9. Heat exchanger according to one of the preceding claims, in which the second chambers (6) able to contain the second fluid (FR) are arranged so as to communicate with a connection device (10) arranged at one end (2A), in the longitudinal direction (A-A'), of the core (2).
10. Heat exchange assembly (30) comprising a heat exchanger (1) according to one of Claims 1 to 9 and an expansion member (40) secured to the heat exchanger (1).
11. Heat exchange assembly according to Claim 10, in which the expansion member (40) comprises a solenoid valve (45).
12. Thermal conditioning system comprising a circuit for refrigerant fluid (FR) and a circuit for heat transfer fluid (FC), at the confluence of which there is installed a heat exchanger according to one of Claims 1 to 9.

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