WO2010149452A1

WO2010149452A1 - Heat-exchanger unit, in particular for an air-conditioning condenser

Info

Publication number: WO2010149452A1
Application number: PCT/EP2010/057248
Authority: WO
Inventors: Anne-Sylvie Magnier-Cathenod; Carlos Martins
Original assignee: Valeo Systemes Thermiques
Priority date: 2009-06-23
Filing date: 2010-05-26
Publication date: 2010-12-29
Also published as: EP2446208A1; FR2947045A1; FR2947045B1

Abstract

The invention relates to a heat-exchanger unit which includes a bundle (12) consisting of an alternating stack of flat tubes (14) for circulating a first fluid (F₁) and disruptors (16) for circulating a second fluid (F₂) between the tubes, flat nozzles (18) in which the respective ends of the tubes (14) are inserted, each of said nozzles (18) being formed by mutually assembling two shells (20) having a bottom (22) in which at least one communication opening (24) is provided, so as to form two series of nozzles (18) at the respective ends of the bundle, the nozzles (18) of each series communicating with the others via the communication openings (24) thereof so as to form an inlet collecting box (26) and an outlet collecting box (28) for the first fluid (F₁); and a housing (30) surrounding the bundle (12), said housing being provided with an inlet (48) and an outlet (50) for the first fluid (F₁) and an inlet (52) and an outlet (54) for the second fluid (F₂). The invention can be used in particular for air-conditioning condensers.

Description

Block of heat exchanger, in particular for air conditioning condenser

The invention relates to heat exchangers, especially for motor vehicles.

It relates more particularly to a heat exchanger block comprising an alternating stack of channels for the circulation of a first fluid and channels for the circulation of a second fluid, and a heat exchanger comprising at least one such block. .

Such heat exchangers can be used, for example, as air conditioning condensers for motor vehicles. The first fluid can then be constituted by a refrigerant, with or without phase change, and the second fluid by a cooling fluid such as glycol water.

Heat exchangers of this type are often made by a technology of stacked plagues having corrugations to disturb the flow of the two fluids, as in document FR 2 846 733. These plagues generally have raised peripheral edges which are assembled together. in a sealed manner to delimit between the plagues of the first and second circulation channels for the respective fluids. The disadvantage of such plagues is that they offer little modularity as regards the size and the adaptation of the passage sections according to the properties of the fluids. Moreover, problems of soldering, and thus of sealing and resistance to pressure, may appear at the level of the fluid passages. Patent FR 2 834 336 teaches a heat exchanger, in particular a condenser, composed of tubes whose ends are received in end pieces, also called "staples", which communicate with each other through lateral openings. However, this solution requires drilling the tubes to ensure the flow of fluid.

Also known from US Pat. No. 6,540,015 is a condenser using tubes for the circulation of a refrigerant and other tubes for the circulation of a cooling fluid. These latter tubes may each consist of at least two plagues.

This solution also has a number of disadvantages, including a complexity of construction. Indeed, the use of a fluid tube involves a lot of material engaged to close the flow of fluids.

The object of the invention is in particular to overcome the aforementioned drawbacks.

It proposes for this purpose a heat exchanger block of the type defined in the introduction, leique comprises a beam formed by an alternating stack of flat tubes for the circulation of the first fluid and disruptive for the circulation of the second fluid between the tubes; flat ends in which are received the respective ends of the tubes, these ends being each formed by the assembly vis-à-vis two coguilles having a bottom in leguel is arranged at least one communication opening, to form two series of ends at the respective ends of the bundle, the end caps of each series communicating with each other via their communication openings to form an inlet manifold and an outlet manifold for the first fluid; and a housing enclosing the bundle, said housing being provided with an inlet and a output for the first fluid and an inlet and an outlet for the second fluid.

Thus, the exchanger of the invention comprises a beam formed by an alternating stack of tubes and disrupters for defining respectively the circulation channels of the first fluid and the second fluid. The end pieces placed at the ends of the tubes make it possible to define, on the one hand, an inlet manifold box at one end of the bundle and, on the other hand, an outlet manifold box at another end of the bundle. These inlet and outlet manifolds are for the first fluid. The flat tips communicate with each other through respective communication apertures that are aligned with each other for each series of tips, without the need for openings through the tubes of the bundle, which simplifies manufacture.

The beam is housed in a housing that contains the second fluid and allows the second fluid to flow between the flat tubes of the beam to achieve a heat exchange between the two fluids.

The entire heat exchanger block can be made from aluminum-based components, suitably plated with a solder alloy, to allow assembly of the block in a single brazing operation.

Such a heat exchanger block is particularly suitable for producing an air conditioning condenser, in particular for motor vehicles, in which the first fluid is a refrigerant and the second fluid is a cooling fluid. The refrigerant may be a fluid with or without a phase change, such as a fluorinated fluid, or a supercritical operating fluid, such as CO ₂ . The second fluid is advantageously water, that is to say usually water added with antifreeze. It may be due to the cooling fluid of the engine of a motor vehicle, or a secondary cooling loop, called a low temperature loop.

In another aspect, the invention relates to a heat exchanger comprising at least one heat exchanger block as defined above. In an advantageous embodiment, this heat exchanger is in the form of a condenser, in that the first fluid is a refrigerant and the second fluid is a cooling fluid.

In this particular application, the heat exchanger advantageously comprises two heat exchanger blocks, namely a condensing block and a sub-cooling block, so that a bottle disposed between them, so that the first fluid, that is to say the refrigerant, passes successively through the condensation block, the bottle and the sub-cooling block.

In the detailed description which follows, made only by way of example, reference is made to the attached drawings on the following:

FIG. 1 is a diagrammatic front view, partially broken away, of a heat exchanger block according to the invention;

- Figure 2 is a perspective view of a coguille for producing a tip; FIG. 3 is a perspective view of a condenser comprising a condensation block and a subcooling block, both made in accordance with the teachings of the invention, thus gu 'a bottle interposed between the two blocks;

- Figure 4 is a longitudinal sectional view of the heat exchanger of Figure 3;

Figure 5 is a cross-sectional view of the heat exchanger of Figure 3;

Figure 6 is a perspective view of a heat exchanger block according to the invention associated with an end cheek; and

FIG. 7 is a perspective view of a heat exchanger comprising a housing having two end flanges according to FIG. 6.

FIG. 1 is firstly shown which shows a block of heat exchanger 10, which includes a beam

12 formed by an alternating stack of flat tubes 14 for the circulation of a first fluid F ₁ and disrupters

16, made in the form of corrugated inserts, for the circulation of a second fluid F ₂ between the tubes 14. The flat tubes are advantageously multi-channel tubes which can be made for example by extrusion or by folding of a metal strip housing an insert or pertubator, as is well known in this art.

The respective ends of the tubes are received in flat tips 18 each formed by the assembly vis-à-vis two coguilles 20 gui each have a bottom 22 in which is arranged at least one communication opening 24. In the example , all the coguilles are identigues between them and they are grouped in pairs by turning each time their concavities towards each other to define a fluid chamber into which a tube end opens.

The tubes 14 are, for example, flat tubes arranged parallel to each other and having the same length. Thus two sets of tips are formed at the respective ends of the bundle, the tips of each series being aligned with each other.

In the example, the tips located on the left side of the figure together form an inlet manifold 26 for the fluid F ₁ , while the ends located on the right side of the figure form an outlet manifold 28 for the fluid F ₁ . A heat exchanger block is thus produced in which the first fluid F ₁ circulates in a single pass, that is to say with an I-circulation, from the inlet manifold 26 to the outlet manifold. 28.

The beam is housed in a housing 30, in the example of generally parallelepipedal shape, which comprises a casing 32 with a bottom wall 34 to which are attached two opposite side walls 36 and two other opposite side walls 38 so as to jointly delimit an open face 40 of generally rectangular shape for receiving a cover 42 to close the open face 40. The cover 42 has a bottom 44 of generally rectangular shape surrounded by a flange 46 intended to be applied against the side walls 36 and 38 of the casing near their free ends to form a tight assembly. The bottom 44 is provided with an inlet opening 48 aligned with the openings 24 of the end pieces 18 of the inlet manifold 26 and an outlet opening 50 aligned with the openings 24 of the end pieces 18 of the manifold. exit 28. Openings 48 and 50 respectively constitute an inlet and an outlet for the fluid F ₁ , which allows this fluid to enter the housing through the inlet opening 48, to then circulate in the tubes of the beam and out through the outlet opening 50, as shown by the arrows F ₁ .

Furthermore, the housing 30 comprises an inlet 52 and an outlet 54 for the fluid F ₂ . In the example, this inlet and this outlet are circular openings made in the same side wall, namely one of the walls 38 of the housing.

The housing 30 thus delimits a chamber for the fluid F ₂ which circulates between the tubes 14, which makes it possible to define an alternating stack of blades for the circulation of the fluids F ₁ and F ₂ . The arrangement of the openings 48 and 50 and the openings 52 and 54 is such that the two fluids circulate in countercurrent to improve the heat exchange. The heat exchanger block of FIG. 1 is capable of numerous variants, in particular as regards the shape and dimensions of the housing and the location possibilities of the respective inlets and outlets for the two fluids.

Reference is now made to FIG. 2, which shows a shell 20 to be assembled with an identical shell 20 to form a flat endpiece 18 together. The shell 20 comprises a flat bottom 22 surmounted by a peripheral assembly edge 56 having a This assembly edge provides a contact surface 58 which is flat and is parallel to the general plane of the bottom 22. Thus, when two shells 20 are arranged opposite each other, that is to say that is, by turning their concavities towards each other, the assembly surfaces 58 of the shells come into contact with each other and can be brazed together by delimiting a chamber, the respective bottoms 22 of the two shells being mutually spaced apart. to define an introductory slot for the end of a tube.

The assembly edge 58 has two free ends 60 located respectively on either side of a free edge 61 of the bottom of the shell. In the example, this free edge is right. When the two shells of the same pair are assembled, thus delimits a chamber for the fluid with a flat slot for the introduction of a tube end. This flat slot has an internal cross section of shape homologous to the external cross section of a tube so as to allow sealing assembly during soldering.

In the example of Figure 2, the bottom 22 of each shell comprises three communication openings, namely a main communication opening 24 located in a central region, near the bottom of the generally U-shaped contour, and two openings of secondary communication 62 arranged on either side of the main communication opening 24.

The shell 20 has a width, as defined between the two free ends 60 of the joining edge 56, which is at least twice its depth, as defined by the dimension in the perpendicular direction between the free edge 61 and the bottom of the contour in the general shape of U. In the example shown, the width of the shell is substantially equal to three times its depth, which provides a very open U shape, favorable to a good circulation of the fluid F ₁ in the collector boxes entry and exit.

Each of the shells advantageously comprises positioning means adapted to cooperate with the positioning means of a shell facing each other to enable their assembly in correct position to form together a flat tip 18.

In the example shown in Figure 2, these means comprise a tab 64 and a notch 66 of homologous shapes spaced from each other and provided respectively in the vicinity of the two ends 60 of the assembly edge. Thus, when two coguilles are placed vis-a-vis, the tab 64 of each coguille is received in the notch 66 of the other coguille, this mistletoe allows to position correctly for assembly by soldering.

As also seen in Figure 2, the flat bottom comprises three stops 68 formed each projecting from the side of the assembly edge to limit the introduction of the free end of a tube.

The cup 20 of FIG. 2 may advantageously be made by stamping and cutting a metal plate, preferably an aluminum plate or aluminum-based alloy suitably coated with solder plating.

Because each plug includes a flat bottom, the flat bottom of a plug can be directly assembled against the flat bottom of an adjacent plug of another pair, i.e. another tip, for realize their mutual assembly. This avoids making a collar around the opening 24 opposite the assembly edge.

In other words, the distance between two adjacent tubes 14 substantially corresponds to twice the material thickness of a said jacket 20. And the height of the disrupter or spacer 16 is twice the thickness of material of a so-called coguille 20, so that the folds said tabs 16 are in contact with said tubes 12.

In the example described, the two shells are identical and independent pieces. It would be possible, however, to form the two shells in one piece with a fastener connecting the two shells and can be folded to bring the two shells closer to each other.

Reference is now made to Figures 3 to 5 which show a heat exchanger 70 here constituted of a condenser and comprising a condensation block 72 and a subcooling block 74, both made in accordance with the teachings of the invention. , as well as a bottle 76 interposed between the blocks 72 and 74.

The condensation block 72 comprises a beam 12 (FIG 4) analogous to that of the fiqure 1, which will therefore not be described in detail. This beam is loqé in a housing 78 formed of a casing 80 of rectangular parallelepipedal shape having a bottom wall 82, two qrandes side walls 84 and two small side walls 86. One delimits and an open face which is closed by a cover 88 .

The subcooling block 74 is analogous and comprises a beam 12 (FIG. 4) formed from the same components as the beam of the block 72, except that it comprises a smaller number of tubes. , end-pieces and disrupters for producing a beam of lower height, as can be seen in FIG. 3. The heat-exchange capacity of the block 74 is therefore smaller than that of the block 72. The beam of the sub-block Cooling 74 is housed in a casing 90 having a casing 92 of rectangular parallelepipedal shape. This casing 92 comprises a bottom wall 94 connected to two large lateral walls 96 and two small lateral walls 98. These side walls delimit between them an open face which is closed by a lid 100 of generally rectangular shape.

The side walls 84 of the block 72 as well as the side walls 96 of the block 74 are widened at the ends of the housing to accommodate respectively the inlet manifold and the outlet manifold for the first fluid F ₁ . Thus, each of the side walls 84 has two opposing bosses 102 and each of the side walls 96 has two opposite bosses 104, in particular formed in continuity with the rest of the housings, for example by stamping. It may be the same in the configuration with single exchanger block (Figure 1).

According to these various embodiments, the side walls of the housing are in contact with the tubes 14, in their portion located between the bosses so that the flow of the fluid F ₂ is well between the tubes 14 and not directly from a boss to the other avoiding the tubes 14. In other words, the inner width of the housing or casings, in their central part, corresponds to the width of the tubes 14, while in their enlarged part, that is to say in the level of said bosses, the inner width of said housing or boxes is greater than the width of said tubes, for example greater than the width of the shells. By "width" of the tubes, the housing or shells and / or shells means the dimension perpendicular to the plane defined by the longitudinal axis of the tubes and the stacking direction of said tubes. The bosses thus define manifolds for the second fluid F2.

If we focus again specifically on the embodiments of FIGS. 3 to 5, the chambers delimited by the housings 78 and 90 communicate directly with each other. thanks to arrangements of the two bosses 102 and the two bosses 104, as seen in Figure 4. For this purpose, at least some of the bosses 102 and 104 have a communication opening for the circulation of the second fluid F2.

Thus, the bosses 104 of the same side wall 96 have an opening surrounded by a circular tip 106 received in an opening 108 of a boss 102 with interposition of a seal 110. Moreover, the opposing bosses 104 have an opening for receiving an inlet pipe 112 and an outlet pipe 114 for the fluid F ₂ . Thus, the same fluid F ₂ can circulate in the respective housings of the two blocks, between the tubes of the respective beams. The fluid F ₂ gui here constitutes a cooling fluid thus serves to cool the fluid F ₁ in the two blocks and then passes successively through the subcooling block 74 and the condensation block 72. In a variant, not shown, the second fluid F ₂ could separately supply the subcooling block 74 and the condensation block 72, the latter then having their own input and output for the fluid F ₂ . The two blocks 72 and 74 are held together by tabs 116 and 118 as seen in FIGS. 3 and 4.

The lid 88 of the condensation block 72 is provided with an inlet flange 120 having an opening 122 for the admission of the fluid F ₁ . This opening 122 supplies the input manifold of the corresponding beam 12. In addition, the cover 88 includes an outlet opening 124 in which is fitted one end of a conduit 126 which is connected to a cover 128 of the bottle 76. This bottle houses a filtering and desiccating cartridge (not shown). From the cover 128 part another conduit 130 for driving the fluid F1 to the subcooling block 74. This conduit 130 opens in an opening 132 of the lid 100 which opens into the inlet manifold of the sub-cooling block 74. At its other end, the lid 100 comprises an outlet flange 134 provided with an outlet opening 136. The lid 128 of the bottle 76 has a flange 138 serving to hold the ends of the conduits 126 and 130.

As a result, the fluid F ₁ , in the example a refrigerant fluid, enters the condensing block 72 through the inlet flange 120 and is cooled in the beam of this block by heat exchanging with the fluid F ₂ , then leaves block 72 to qaqner bottle 76 in which it is filtered and dehydrated. Then, the fluid F ₁ qaqne the inlet opening 132 of the subcooling block 74, circulates in the beam of this block where it is cooled again by the fluid F ₂ and then leaves this block by the outlet flange 134 .

In a condenser of this type, the fluid may be a phase-shifting fluid such as a fluoro fluid or a supercritical fluid such as CO ₂ . The different components will be adapted according to the pressures to be withstood, particularly high pressures when it is a CO ₂ type fluid.

In this case, it will be advantageous to use flat tubes made by extrusion and including internal channels of generally circular section.

The bottle 76 is disposed substantially substantially at least one of the condensation block 72 and the subcooling block 74 to reduce the bulk. In the embodiment of Figs 3 to 5, where the two blocks are arranged to have two of their side walls 84, 96 facing each other, the bottle 76 is disposed substantially at one of the side walls 84 of the condensing block 72 and the cover 100 of the sub-cooling block 74, that is to say tangentially to two walls perpendicular to each other. This tangential arrangement of the bottle can be applied to other embodiments, in particular as to the embodiment of the bundle, such as stacked plate bundles or end plate bundles having a concavity oriented in the same direction. meaning, as discussed below. Such an arrangement makes it possible to propose a more compact heat exchanger than that described in document FR 2 846 733, mentioned above, which has a large bulk in the stacking direction of the plates.

Figures 6 and 7 refer to another heat exchanger in which the housing is made differently, that is to say without housing or cover as in the previous embodiments.

Here, the heat exchanger 140 comprises a housing 142 having a casing 144 of generally parallelepipedal shape having two large opposite side walls 146 and two small opposite side walls 148 for delimiting two opposite open faces, each of substantially rectangular shape. Each of these open faces is closed by a cheek 150 having a peripheral edge 152 provided with crimping tabs 154 adapted to grip a peripheral edge of the envelope with insertion of a seal (not shown). In such an embodiment, said flange 150 is, for example, secured, in particular brazed to the beam 12.

The heat exchanger 140, which may be for example a condenser, comprises tubings 156, 158, 160 and 162 for the admission or discharge of a fluid and which will not be described in detail. Likewise, a cheek 150 door tubings 164 and 166 and another plays 150 door tubings 168 and 170 which will not be described in detail.

In the embodiments of FIGS. 3 to 5 and that of FIGS. 6 and 7, the inlet and outlet manifolds for the fluid F ₁ consist of stacked tips each formed by the assembly facing each other. two shells having a bottom in which is arranged at least one communication opening. However, in an alternative embodiment, not shown, it is also conceivable to make each of the manifolds by a stack of end plates having a bottom provided with a peripheral edge with a generally U-shaped contour. end are then assembled in pairs in a sealed manner by cooperation of their respective peripheral edges, having all their concavity in the same direction. This solution avoids the use of pairs of shells and reduces the bulk in the direction of the stack.

The heat exchanger block of the invention is particularly suitable for producing heat exchangers for motor vehicles, in particular air conditioning condensers.

Claims

claims

Heat exchanger block comprising an alternating stack of channels for the circulation of a first fluid (F ₁ ) and channels for the circulation of a second fluid (F ₂ ),

characterized in that it comprises a beam (12) formed by an alternating stack of flat tubes (14) for the circulation of the first fluid (F ₁ ) and disrupters (16) for the circulation of the second fluid (F ₂ ) between the tubes; flat ends (18) in which the respective ends of the tubes (14) are received, these ends (18) being each formed by the assembly facing two shells (20) having a bottom (22) in which is arranged at least one communication opening (24), to form two series of end pieces (18) at the respective ends of the beam, the end pieces (18) of each series communicating with each other through their communication openings (24) to form an inlet manifold (26) and an outlet manifold (28) for the first fluid (F ₁ ); and a housing (30) enveloping the beam (12), said housing being provided with an inlet (48) and an outlet (50) for the first fluid (F ₁ ) and an inlet (52) and a an outlet (54) for the second fluid (F ₂ ).

2. Heat exchanger block according to claim 1, characterized in that the bottom (22) of each shell (20) is generally flat, which allows a direct contact between the bottoms of two shells belonging to two end pieces (18). ) adjacent for their mutual assembly by brazing.

3. Heat exchanger block according to one of claims 1 and 2, characterized in that the bottom (22) of each shell (20) is surmounted by a peripheral edge (56) shaped contour general of U, said assembly edge (56) having two free ends (60) located respectively on either side of a free edge

(61) from the bottom of the shell, so that two shells joined in facing relation by their respective joining edges (56) define a fluid chamber with a flat slot for the introduction of a tube end .

4. heat exchanger block according to claim 3, characterized in that each shell (20) has a width, as defined between the two free ends (60) of the connecting edge (56), at least equal to two its depth, as defined by the dimension in the perpendicular direction between the free edge (61) and the bottom of the generally U-shaped contour.

5. Heat exchanger block according to one of claims 1 to 4, characterized in that the bottom (22) of each shell (20) comprises a main communication opening (24) surrounded by two secondary communication openings ( 62).

6. heat exchanger block according to one of claims 1 to 5, characterized in that each shell (20) comprises positioning means (64, 66) adapted to cooperate with the positioning means (64, 66). a shell vis-à-vis to allow their assembly in the correct position to form together a flat tip (18).

7. Heat exchanger block according to claim 6, characterized in that the positioning means comprise a tab (64) and a notch (66) of homologous shapes spaced apart from each other.

Heat exchanger block according to one of claims 1 to 7, characterized in that the housing (30) comprises a housing (32) having a bottom wall (34) and side walls (36, 38) defining an open face (40), and a cover (42) for closing the open face of the housing.

9. heat exchanger block according to one of claims 1 to 7, characterized in that the housing (142) comprises a casing (144) having side walls (146, 148) defining two opposite open faces, and two opposing cheeks (150) for respectively closing the two open faces of the envelope.

Heat exchanger block according to one of claims 1 to 9, characterized in that the inlet manifold (26) and the outlet manifold (28) for the first fluid (F ₁ ) are accommodated. in two end of the housing (30; 78; 90; 142).

Heat exchanger block according to claim 10, characterized in that the housing (78; 90) has sidewalls (84; 96) enlarged at both ends to respectively accommodate the inlet header (26) and the outlet manifold (28) for the first fluid (F ₁ ).

12. Heat exchanger block according to claim 11, characterized in that the side walls (84; 96) have opposing bosses (102; 104), at least some of which have a communication opening for the circulation of the second fluid ( F ₂ ).

13. Heat exchanger comprising at least one heat exchanger block (10; 72; 74) according to one of claims 1 to 12.

14. Heat exchanger according to claim 13, in the form of a condenser, in which the first fluid (F ₁ ) is a refrigerant and the second fluid (F ₂ ) is a cooling fluid.

15. Heat exchanger according to claim 14, characterized in that it comprises two heat exchanger blocks according to one of claims 1 to 8, namely a condensation block (72) and a sub-cooling block (74), and a bottle (76) arranged between them, so that the first fluid (F ₁ ), which is the refrigerant, passes successively through the condensation block (72), the bottle (76) and the subcooling block (74).

16. Heat exchanger according to claim 15, characterized in that it comprises an inlet flange (120) and an outlet flange (136) for the first fluid (F ₁ ) disposed respectively on the condensation block (72). and on the subcooling block, as well as conduits (126, 130) connecting the bottle (76) to the condensing block (72) and the subcooling block (74).

17. Heat exchanger according to one of claims 15 and 16, characterized in that the second fluid (F ₂ ), which is the cooling fluid, passes successively through the sub-cooling block (74) and the condensing block. (72).

18. Heat exchanger according to claim 17, characterized in that it comprises an inlet pipe (112) and an outlet pipe (114) for the second fluid (F ₂ ) both arranged on the sub-block. cooling (74), the second fluid (F ₂ ) passing from the subcooling unit (74) to the condensing unit (72) and then from the condensing unit (72) to the subcooling unit (74) through openings vis-à-vis arranged in the respective housings (78; 90) of said blocks (72; 74).

19. Heat exchanger according to one of claims 15 and 16, characterized in that the second fluid (F ₂ ), which is the cooling fluid, separately feeds the sub-cooling block (74) and the condensing block. (72).

20. Heat exchanger according to one of claims 15 to 19, characterized in that the bottle (76) is disposed substantially tangentially to at least one of the condensation block (72) and the sub-cooling block (74).