EP0686823B1 - Heat exchanger, more particularly for cooling an air flow with high temperature - Google Patents

Description

The invention relates to a heat exchanger of the type comprising a bundle of tubes mounted between two manifolds as defined in the preamble of claim 1.

We already know many heat exchangers of this type in which a first fluid, generally water, enters one of the manifolds and goes through then the tubes of the beam to gain the other box collector and leave the heat exchanger, after having heat exchanged with another fluid, usually an air flow, which sweeps the beam tubes.

Such heat exchangers are mainly used in as air / water exchangers and find applications various in the automotive industry, especially to serve cooling an engine or heating the passenger compartment.

However, heat exchangers of this type could not to prevail, given the high temperatures involved, for the treatment of a high temperature air flow, such as cooling an air flow from the turbocharger of a motor or industrial vehicle.

Indeed, the air flow from a turbocharger is at a high temperature, generally around 250 ° C, which must be lowered to a temperature of around 100 ° C by heat exchange with cooling water or cooling air.

In this particular application for cooling the air flow from a turbocharger, we used up to present particular exchangers, called "heat exchangers plates and bars ", which include two fluid boxes, a multiplicity of spacer bars arranged by pairs, as well as a multiplicity of plates arranged by pairs to frame the pairs of bars and form collaboration with them fluid circulation channels.

A heat exchanger of this type is known in particular from French Patent No 80 06 704 published under No 2,479,438.

It is also known from documents FR-A- 2,563,899 and EP-A-0324226 a heat exchanger comprising a bundle of tubes mounted between two manifolds, in which each manifold includes a stack of joined shells in pairs, and in which each shell comprises a wall closed side with one end connected to a flange exterior plane and of which another end is connected to a inner flat edge which extends parallel to the flat edge exterior and which delimits an axial opening, the wall lateral of each shell delimiting a lateral opening whose section is adapted to the right half-section of a tube, so that the shells can be assembled by pairs alternately by their inner edges and by their outer edges delimiting an internal chamber along the entire length of the stack and that the ends tubes can be received each in the two openings lateral of two adjacent shells.

The main drawback of plate and strip heat exchangers or shell stack exchangers resides in the complexity of assembling the different elements that make up and the respective immobilization of the elements the relative to each other.

It is likewise known, from document FR-A-2 194 933, a exchanger consisting of a stack of plates in the form of cuvettes joined in pairs to form an internal chamber in which a fluid is caused to circulate, each plate of a pair of plates being positioned relative to the plaque facing him. A stack of pairs of plates as well is then formed to be assembled, in particular by soldering.

This provision has a significant disadvantage in the sense that it does not immobilize the plates of a same pair of plates relative to each other and, when manipulations to stack the pairs of plates, some plates may no longer be properly positioned relative to the plates facing them. Of made this wrong positioning, and after the operation assembly by brazing, the exchanger thus produced will have a serious defect in its operation, such as poor sealing between the plates of a pair of plates.

The object of the invention is in particular to overcome such disadvantages.

It also aims to provide a heat exchanger of the type with manifolds and tube bundles which can be used for different applications and in particular for treatment of a high temperature air flow such as the flow air from a turbocharger.

The invention also aims to provide such an exchanger heat which can be easily assembled, in particular by soldering, while providing maximum safety in the final constitution of this exchanger.

The invention provides for this purpose a heat exchanger of type defined in the introduction, in which the flat edge outside of each shell includes indexing means suitable for ensuring correct relative positioning of the two shells of the same pair with a view to their assembly by their respective outer edges and wherein said edge exterior includes at least one folding crimp tab formed at the periphery for the assembly of the two shells of the same pair.

Thus each of the manifolds is formed by a stack of shells, i.e. elements in the form of bowls, which can be assembled two by two between which can also be assembled at the ends beam tubes.

Such a heat exchanger can be easily produced by brazing of the shells and of the tubes together, said shells and said tubes being formed of a metal alloy appropriate.

A heat exchanger of this type is suitable especially for cooling the charge air from a turbocharger, the charge air entering one of the collecting chambers, traversing then the tubes of the beam before regaining and leaving the other collecting chamber.

High temperature charge air is cooled advantageously by an air flow which sweeps the tubes of the beam.

Advantageously, the lateral opening of a shell is bounded by a region set back from the inner rim, which region is closer to the plane of the outer rim than so is the interior ledge plan.

According to a preferred characteristic of the invention, the tubes each have a substantially rectangular cross section bounded by two long sides and two short sides, the region set back from the inner rim comprising a central part of length substantially equal to one long side and two parts side length substantially equal to half of a small side.

So when two shells are joined together by their respective interior edges, their two openings side define a complete opening of adapted section to the cross section of a tube.

According to another particular embodiment of the invention, the region in inner rim removal attaches to a region substantially straight on the side wall.

Advantageously, the side wall also comprises a substantially semicircular region which connects to this region straight.

According to another particular embodiment, the side wall has a shape in skin which flares out from the flat edge inside towards the outside edge.

This particular structure facilitates the realization of a shell by stamping or punching with a punch appropriate.

According to another particular embodiment of the invention, the means for indexing a shell include two folded legs each formed in a punctured on the outer rim and suitable for entering into corresponding openings of another shell. These legs can act as indexing legs and / or legs crimping.

The exchanger of the invention advantageously comprises corrugated heatsinks or spacers arranged on one side and on the other side of the bundle tubes.

According to another preferred characteristic of the invention, the exchanger includes an end cheek that extends parallel to the tubes and which is assembled to the two shells located at a first end of each manifold, said cheek being equipped with two pipes respectively serving the admission and evacuation of a fluid passing through the fluid boxes and bundle tubes, while both shells located at a second end of each box collector are closed.

These last shells are either closed by a cheek common, either constituted by specific shells with a continuous bottom at the level of the interior flat edge.

• la figure 1 est une vue en perspective d'un échangeur de chaleur selon l'invention;
• la figure 2 est une vue en perspective d'une coquille dans une première forme de réalisation;
• la figure 3 est une vue partielle en coupe longitudinale d'un échangeur de chaleur muni de coquilles conformes à la figure 2;
• la figure 4 est une vue en coupe selon la ligne IV-IV de la figure 3;
• la figure 5 est une vue partielle en coupe transversale d'un échangeur de chaleur selon une seconde forme de réalisation de l'invention;
• la figure 6 est une vue en coupe selon les lignes VI(A)-VI(A), VI(B)-VI(B) et VI(C)-VI(C) de la figure 5;
• la figure 7 est une vue en coupe selon la ligne VII-VII de la figure 5;
• la figure 8 est une vue en coupe transversale partielle d'un échangeur de chaleur selon une troisième forme de réalisation de l'invention;
• la figure 9 est une vue en coupe selon la ligne IX-IX de la figure 8;
• la figure 10 est une vue en coupe transversale partielle d'un échangeur de chaleur selon une quatrième forme de réalisation de l'invention; et
• la figure 11 est une vue en coupe selon la ligne XI-XI de la figure 10.

In the description which follows, given by way of example, reference is made to the appended drawings, in which:

• Figure 1 is a perspective view of a heat exchanger according to the invention;
• Figure 2 is a perspective view of a shell in a first embodiment;
• Figure 3 is a partial view in longitudinal section of a heat exchanger provided with shells according to Figure 2;
• Figure 4 is a sectional view along the line IV-IV of Figure 3;
• Figure 5 is a partial cross-sectional view of a heat exchanger according to a second embodiment of the invention;
• Figure 6 is a sectional view along lines VI (A) -VI (A), VI (B) -VI (B) and VI (C) -VI (C) of Figure 5;
• Figure 7 is a sectional view along line VII-VII of Figure 5;
• Figure 8 is a partial cross-sectional view of a heat exchanger according to a third embodiment of the invention;
• Figure 9 is a sectional view along the line IX-IX of Figure 8;
• Figure 10 is a partial cross-sectional view of a heat exchanger according to a fourth embodiment of the invention; and
• FIG. 11 is a sectional view along the line XI-XI of FIG. 10.

The heat exchanger shown in Figure 1 includes a fluid box 10 connected to an intake manifold 12, a fluid box 14 connected to a discharge pipe 16 and a bundle 18 mounted between the two manifolds 10 and 14.

The bundle 18 is formed by a multiplicity of tubes 20 parallel, of rectangular section, the ends of which respective open into the two manifolds. Between the tubes 20 are further arranged heatsinks 22 in the form of corrugated dividers.

The heat exchanger is suitable for being traversed by a first fluid, for example charge air from a turbocharger, which enters the manifold 10 through tubing 12, then runs through tubes 20 to go to the manifold 14 and leave it by the discharge pipe 16, as shown by the arrows F1. This first fluid exchanges heat with a second fluid which scans the beam 18 as shown by the arrow F2.

Each of the manifolds 10 and 14 includes a stack identical shells assembled in pairs and alternately, one of which is shown in perspective in figure 2.

The shell 24 is formed by stamping or punching with from a metal sheet, preferably stainless steel. The shell 24 includes a closed side wall 26 having a substantially rectilinear region 28 which is connects to a substantially semi-circular region 30.

At its upper end (FIG. 2), the wall 26 is connects to an outer flat edge 32 which has a substantially straight portion 34 connected to region 28 of the wall 26 and a portion 36 of substantially shaped semicircular which connects to region 30 of the wall 26. The rim 32 extends radially outwards at from the wall 26.

At its lower end (FIG. 2), the wall 26 is connects to an inner flat edge 38 which extends parallel at the outer plane edge 32 and which delimits an opening axial 40 of substantially semi-circular shape.

The inner rim 38 extends radially inward from the wall 26.

As can be seen in Figures 2 to 4, the wall 26 is formed into a skin so as to flare from the rim inner plane 38 towards the outer plane edge 32.

As shown in FIG. 2, the internal flat edge 38 comprises a substantially semi-circular portion 42 extending in the general plane of the rim 38 and connecting to the region 30 of the wall 26. The portion 42 is connected to a recessed region which is also part of the ledge inside and which is closer to the edge plane exterior than is the interior rim plan.

This recessed region includes a central portion 44 (Figures 2 to 4) which extends parallel to the plane of the two ledges 32 and 38 as well as two lateral parts 46 connecting the central part 44 to the portion 42.

As best seen in Figures 3 and 4, the shells 24 are intended to be stacked and assembled in pairs alternately by their inner edges 38 and by their outer edges 32. Which allows to delimit a room internal 48 (FIG. 3) extending over the entire height of stacking.

When two shells 24 are joined by their edges respective interiors 38, their recessed regions delimit respectively two lateral openings 50 (FIG. 2) suitable for receiving together the end of a tube 20 of the beam.

In the example, the tubes 20 have a cross section of shape substantially rectangular bounded by two long sides and two small sides.

The central part 44 of the recessed region has a length substantially equal to a large side, while the two side parts 46 have a length substantially equal to the half of a small side.

In other words, the central part 44 and the two parts lateral 46 of the same shell 24 delimit an opening lateral which corresponds substantially to the straight half-section of a tube.

The beam 18 formed by the tubes 20 and the heatsinks 22 is mounted between the manifolds 10 and 14 formed each by a stack of shells 24. The tubes 20 and the heatsinks 22 are advantageously formed from a alloy of stainless steel and aluminum.

After assembly and assembly of the various constituent elements of the exchanger, these are advantageously combined them by brazing in the oven.

As seen in Figure 1, the heat exchanger includes two end cheeks 52 and 54 located respectively in the upper part and in the lower part in the position of figure 1.

The cheek 52 extends parallel to the tubes 20 and is assembled to the two shells 24 located at the upper end manifolds 10 and 14. This cheek 52 is equipped tubes 12 and 16 itself.

The cheek 54 extends parallel to the tubes and is assembled to the two shells 24 situated respectively at the ends opposite manifolds 10 and 14.

The cheek 54 thus makes it possible to close the last shell of the stacking of the manifold 10 or of the box collector 14.

In a variant (not shown), it would be possible to provide specific shells with a background continuous in place of the inner edge 42 and which close thus the end of a fluid box.

As shown in Figure 2, the portion 34 of the outer rim 32 includes two indexing tabs 56 formed in punctures and two openings 58 of corresponding shape.

When two shells 24 are assembled by their edges outside 32, the two indexing tabs 56 of a shell enter the two openings 58 of the other shell and vice versa, which ensures correct relative positioning of the two shells of the same pair with a view to their assembly subsequent by soldering.

We now refer to the embodiment of the figures 5 to 7 in which the elements common with those of the first embodiment are defined by the same numerical references increased by 100.

The shell 124 is similar to the shell 24 described above. It differs from the latter in that the outer plane edge 132 has a substantially rectangular shape with four rounded corners instead of a shape substantially semi-circular.

The rim 132 comprises two indexing lugs 156 formed in punctures in a region 136 of the edge located on the side of the semi-circular region 130 of the side wall 124.

This region 136 continues with a folded edge 137 which extends in a plane parallel to the direction of the stack.

When the shells are stacked, the flanges 137 define a support surface on which a plate is assembled support 160 comprising a core 162 to which it is connected perpendicularly a wing 164 (Figures 5 and 6).

The shell 124 also differs from the shell 24 by the causes the opening 140 to be crossed radially by a material bridge 141.

Figure 6 shows, in section, the constitution of the exchanger heat respectively at the cutting planes VI (A), VI (B) and VI (C) in Figure 5.

We now refer to the embodiment of the figures 8 to 9 which constitutes a variant of the embodiment Figures 5 to 7. The common elements are designated under the same reference numbers increased by 100.

The main difference is that the ledge exterior 232 has, in its region 234, a tab 259 which occupies less than half a width of the shell. When two shells are joined by their outer edges 232, the 256 tabs allow indexing, while both legs 259 can be folded up as shown in figure 9 to ensure prior crimping of the two shells 224.

We now refer to the embodiment of the figures 10 and 11 which constitutes a variant of that of FIGS. 8 and 9. Common elements with those of the embodiment previous are designated by the same references numerical values increased by 100.

In this variant, the main difference lies in the fact that the crimping lug 359 extends over a longer narrow width. In addition, the indexing tabs 256 serve also crimping lugs, as shown in the figure 11.

After positioning two shells 324 by their edges respective exteriors 332, the indexing lugs 356 are folded back to also serve as crimp tabs.

Likewise, the legs 359 are folded back to ensure the crimping.

Of course, the invention is not limited to the forms of realization described previously by way of example.

It will be understood that the invention is not limited to an exchanger heat used to cool an air flow by heat exchange with another air flow and that it can be used to provide heat exchange between other types of fluids.

Claims (10)

1. Heat exchanger comprising a bank of tubes mounted between two manifolds, in which each manifold (10, 14) comprises a stack of shells (24) joined together in pairs, and in which each shell (24) comprises a closed sidewall (26) one end of which is connected to a flat, outer rim (32) and another end of which is connected to a flat, inner rim (38) which extends parallel to the flat, outer rim and which delimits an axial opening (40), the sidewall (26) of each shell (24) delimiting a lateral opening (50) the cross section of which is matched to the half-cross-section of a tube (20), in such a way that the shells (24) can be assembled in pairs alternately by their inner rims (38) and by their outer rims (32), delimiting an inner chamber (48) over the entire length of the stack, and that the ends of the tubes (20) can each be held in the two lateral openings (50) of two adjacent shells (24), characterised in that the flat, outer rim (32; 132; 232; 332) of each shell includes indexing means (56; 156; 256; 356) suitable for ensuring correct relative positioning of the two shells of the same pair with a view to assembling them by their respective outer rims, and in that the said outer rim comprises at least one foldable crimping lug formed at the periphery with a view to assembling the two shells of the same pair.
2. Exchanger according to Claim 1, characterised in that the lateral opening (50) of a shell (24) is delimited by a recessed region (44, 46) of the inner rim (38), this recessed region being closer to the plane of the outer rim (32) than the plane of the inner rim (38) is.
3. Exchanger according to Claim 2, characterised in that the tubes (20) each have a substantially rectangular cross section delimited by two large sides and two small sides, and in that the recessed region of the inner rim (38) comprises a central part (44) substantially equal in length to a large side and two lateral parts (46) substantially equal in length to half of a small side.
4. Exchanger according to one of Claims 2 and 3, characterised in that the recessed region of the inner rim (38) is attached to a substantially straight-line region (28) of the sidewall (26).
5. Exchanger according to Claim 4, characterised in that the sidewall (26) further includes a substantially semicircular region (30) which is connected to the straight-line region (28).
6. Exchanger according to one of Claims 1 to 5, characterised in that the sidewall (26) has a raked shape which widens out from the flat, inner rim (38) towards the flat, outer rim (32).
7. Exchanger according to one of Claims 1 to 6, characterised in that the indexing means of a shell comprise two folded lugs (56; 156; 256; 356) each formed in a cutout of the outer rim (32; 132; 232; 332) and able to be inserted into corresponding openings of another shell.
8. Exchanger according to one of Claims 1 to 7, characterised in that it comprises dissipators (22) arranged on either side of the tubes (20) of the bank.
9. Exchanger according to one of Claims 1 to 8, characterised in that it comprises an end cheek (52) which extends parallel to the tubes_ (20) and which is assembled to the two shells situated at a first end of each manifold (10, 14), the said cheek (52) being equipped with two pipes (12, 16) serving respectively for taking in and discharging a fluid passing through the manifolds and the tubes of the bank, while the two shells situated at a second end of each manifold are closed.
10. Exchanger according to Claim 9, characterised in that the shells (24) situated at the second end of each manifold (10, 14) are either closed by a common cheek (54), or consist of special shells with a continuous bottom, level with the flat, inner rim (38).

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