FR2855604A1 - Heat exchanger for motor vehicle, has blocking unit placed between envelope and separators for blocking passage of charge air from input collector to output collector, where separators are arranged in charge air channel - Google Patents

Abstract

The exchanger has a heat exchange beam with a stack of plates determining between them circulation channel for charge air to be cooled and a water circulation channel. Separators (32) are arranged in the charge air circulation channel. A blocking unit (44) placed between an envelope and the separators blocks the passage of the charge air from an input collector to an output collector.

Description

-i "2855604

  The invention relates to heat exchangers, and more particularly to plate heat exchangers for motor vehicles.

  It relates more particularly to a heat exchanger for the heat exchange between a fluid to be cooled and a cooling fluid, comprising a heat exchange bundle consisting of a stack of plates determining between them alternating circulation channels for the fluid 15 to be cooled and for the coolant, dividers being arranged in the circulation channels of the fluid to be cooled, an envelope housing the heat exchange bundle, an inlet manifold for distributing the fluid to be cooled in the channels circulation of the fluid to be cooled and an outlet manifold for discharging the fluid to be cooled from the circulation channels of the fluid to be cooled.

  In exchangers of this type, the plates most often have the general shape of an elongated rectangle having two short sides, each plate having two bosses located along the same short side of the plate, these bosses being in abutment on the bosses of an adjacent plate to respectively form an inlet manifold and an outlet manifold for the coolant.

  The spacers, which are generally of corrugated shape, form secondary exchange surfaces and / or disturbing elements. They are arranged in the circulation channels of the fluid to be cooled, have a length corresponding to the total length of the plates minus the space occupied by the bosses which constitute the inlet manifold and the outlet manifold of the cooling fluid. Consequently, there are gas leaks to be cooled between the end of the inserts and the envelope of the heat exchange bundle. These leaks put the inlet manifold and the outlet manifold of the fluid to be cooled in direct communication, without passing through the heat exchange surface. The fluid which passes through these leaks is not cooled, which results in a reduction in the heat exchange efficiency of the exchanger.

  The object of the invention is precisely to produce a heat exchanger which overcomes these drawbacks. The heat exchanger of the invention comprises, for this purpose, sealing means situated between the casing and the spacers to prevent the passage of the fluid to be cooled from the inlet manifold to the outlet manifold.

  In a particular embodiment, these sealing means consist of at least one partition disposed between the inlet manifold and the outlet manifold of the cooling fluid. This partition may have, in particular, a U-shaped section. In another embodiment, the closure element is constituted by a closure element having a U-shaped section and mounted on the heat exchange bundle along the short side of the plates comprising the inlet manifold and the coolant outlet manifold.

  In yet another embodiment, the sealing means are constituted by a flange formed at the periphery of the bosses of the plates, this flange extending at least from the spacers to the envelope of the heat exchange bundle.

  Finally, in yet another embodiment, the sealing means 35 are constituted by a stamp formed between the two bosses of the plates of the heat exchanger.

  This stamping may include a fallen edge which bears against the envelope in order to facilitate the production of a sealed connection during the brazing operation of the exchanger.

  These sealing means thus make it possible to eliminate the leak of gas to be cooled which exists in the exchangers of the prior art. Consequently, all of the fluid to be cooled is forced to flow through the heat exchange surface so that the thermal efficiency of the heat exchanger is not reduced. 10 Other characteristics and advantages of the invention will become apparent on reading the following description of embodiments given by way of illustration with reference to the appended figures. In these figures: Figure 1 is a perspective view of a heat exchanger according to the prior art; - Figure 2 is an enlarged partial sectional view of the prior art heat exchanger of Figure 1; Figure 3 is a partially exploded perspective view of a heat exchanger according to a first embodiment of the invention; - Figure 4 is a perspective view of a second embodiment of a heat exchanger according to the present invention; - Figure 5 is a perspective view, partially exploded, of a third embodiment of a heat exchanger according to the invention; and - Figure 6 is a partially exploded perspective view of a heat exchange bundle illustrating a third embodiment of the invention.

  There is shown in Figures 1 and 2 respectively a perspective view and a partial sectional view of a plate heat exchanger, in the example a charge air cooler of a motor vehicle, in accordance with prior art 5. It consists of a heat exchange bundle, designated by the general reference 2, contained inside an envelope designated by the general reference 4. The bundle is formed by the superposition of a plurality of stamped plates 8 generally 10 rectangular. Each plate 8 has a substantially flat bottom wall 10, surrounded by a peripheral rim 12 terminated by a flat 14. The bottom 10 and the rim 12 determine a shallow bowl intended for the circulation of the cooling fluid.

  As can be seen more particularly in FIG. 2, the plates 8 are grouped in pairs and assembled by their flats 14. In this way, the bowls of the upper plate 8a and of the lower plate 8b of a pair of 20 plates are added to constitute a channel 16 for circulation of the cooling fluid. Furthermore, two bosses 18 are formed along a short side of the rectangle formed by each of the plates. The bottom of each boss has a circulation passage 20 for the cooling fluid. The bosses of a pair of plates 8a, 8b are supported on the bosses of the pairs of adjacent plates. This produces an inlet manifold 22 and an outlet manifold (not referenced) for the cooling fluid. The cooling fluid enters the bundle as shown diagrammatically by the arrow 24, then circulates, from left to right according to FIG. 2, in the circulation channels 16 as shown diagrammatically by the arrows 26. The outlet of the fluid from the exchanger s 'performs in reverse.

  The bosses of two pairs of plates determine between them circulation channels 30 for the fluid to be cooled, generally a gas. As can be seen in FIG. 1, the circulation channels 30 of the gas to be cooled, the charge air in the example, are perpendicular to the circulation channels 16 of the coolant, generally the water in the cooling circuit of the vehicle engine. The circulation of these two fluids is thus carried out at crossed currents. In order to improve the heat exchange, 5 of the spacers 32 are arranged in each of the circulation channels 30. They are in the form of corrugated spacers having an inclined wall 34 extending obliquely to the bottom walls 10 plates 8 of the exchanger. These spacers form secondary exchange surfaces 10 and / or disturbing elements.

  The envelope 4 consists of an upper half-casing 5 and a lower half-casing 6 fitted one inside the other so as to house the heat exchange bundle. Two openings 7 (only one shown in FIG. 1) are provided in the upper half-casing 5 of the casing for the inlet and the outlet of the coolant. The upper half-casing 5 and the lower half-casing 6 have a generally rectangular shape. Their width is slightly greater than the width of the plates 8 so as to provide, along each of the long sides of the plates, respectively an inlet manifold and an outlet manifold for the fluid to be cooled.

  An inlet manifold and an outlet manifold (not shown) are adapted to the periphery of the casing 4 for supplying and evacuating the charge air. As can be seen, the corrugated spacers 32 extend over the entire length of the plates, 30 with the exception of the part which includes the bosses 18. There therefore exists between the vertical wall of each of the demounters 5 and 6 and the end inclined wall 34 of each of the corrugated inserts, passages 38 which directly connect the inlet manifold and the outlet manifold of the gas to be cooled, without this gas passing through the heat exchange surface materialized by the inserts corrugated 32. The passages 38 therefore constitute leaks detrimental to the proper functioning of the exchanger, as shown by the arrows F in FIG. 1.

  FIG. 3 shows a partially exploded perspective view of a charge air cooler according to the invention. In this embodiment, a cutout 40 is provided on each of the plates 8 between the 5 bosses 18 constituting the inlet manifold and the bosses constituting the outlet manifold of the cooling fluid. A partition 42 is inserted in the cutout 40. In order to completely seal the leakage passages 38, the partition 42 extends from the vertical sides 9 of each of the half-housings 5 and 6 to the inclined end wall 34 of each of the corrugated spacers 32. This partition can take different forms without departing from the scope of the invention. In the example shown in FIG. 3, the partition 42 has a U-shaped cross section. This section is advantageous because it allows significant contact between the flat part of the U and the inclined end wall 34 of the corrugated inserts , which ensures a good bond during soldering. Similarly, the partition 42 has flanges folded perpendicularly to the branches of the U so as to ensure a good connection surface between the ends of the branches of the U and the vertical walls 9 of the housings 5 and 6.

  FIG. 4 shows a perspective view of a second embodiment of sealing means according to the invention. These means consist of a closure element, designated by the general reference 44, which has the shape of a U. It comprises a bottom wall 45 and two cheeks 46 substantially perpendicular to the wall 45. 30 The element d shutter 44 is applied to the outside of the bundle. The bottom wall 45 is pressed against the short side of the plates 8 comprising the bosses 18. The side cheeks 46 have a length such that they extend substantially to the inclined end walls 34 of the 35 corrugated inserts 32. The side cheeks 46 are also preferably connected to the bottom 44 by a radius of curvature equal to that of the plates 18. Thus, the shutter element 44 prevents the charge air to cool to pass through the exchanger outside the zone d heat exchange between the corrugated spacers. Leaks are thus eliminated.

  FIG. 5 shows a perspective view of a third embodiment of the invention. Each of the plates 8 has a dropped edge 48 which partially surrounds the bosses 18. The fallen edges are preferably produced by stamping at the same time as the other reliefs of the plate 8. The dropped edges 48 are preferably limited to the rear part bosses so as not to engage excess material. However, it is necessary, in accordance with the invention, that they extend at least, in the direction of the length of the plates, from the inner wall of the casing 4 to the inclined end walls 34 of the corrugated inserts 15 . The fallen edges 48 thus constitute a simple and inexpensive means of closing the leakage passages 38 (FIG. 2).

  FIG. 6 shows a perspective view of a fourth embodiment of the invention. Each of the plates 8 comprises a stamped 50 formed between two bosses 18. These stamps are located on the same side, relative to the bottom wall 10 of the plate, as the bosses 18. The flat faces of the stamped 50 are tightly linked to each other by soldering.

  In the lengthwise direction of the plates, each boss 50 extends substantially from the terminal end of the corrugated spacers 32 to the internal wall 9 of the half-housings 5 and 6 so as to close the leakage passages as completely as possible 38. The stampings 50 thus constitute a simple and inexpensive means of closing these leakage passages. In fact, they can be produced in a simple manner, by stamping, at the same time as the other reliefs of the plate. On the other hand, they do not require the addition of an additional part or an addition of material, since they are made in the surface of the plate itself.

  The invention is not limited to charge air coolers and also applies to other types of heat exchangers.

Claims (8)

claims   1. Heat exchanger, for the heat exchange between a fluid to be cooled and a cooling fluid, comprising a heat exchange bundle (2) consisting of a stack of plates (8, 8a, 8b) determining between them alternating circulation channels for the fluid to be cooled (30) and for the cooling fluid (16), spacers (32) being arranged in the circulation channels 10 (30) of the fluid to be cooled, an envelope (4 ) housing the heat exchange bundle, an inlet manifold for distributing the fluid to be cooled in the circulation channels of the fluid to be cooled, and an outlet manifold for discharging the fluid to be cooled, characterized in that it 15 comprises sealing means (42, 44; 48, 50) located between the casing and the spacers to prevent the passage of the fluid to be cooled from the inlet manifold to the outlet manifold.   2. Heat exchanger according to claim 1, characterized in that the plates (8) have the general shape of an elongated rectangle having two short sides, each plate (8) comprising two bosses (18) located along a same small side of the plate, the bosses (18) of a plate being supported on the bosses (18) of an adjacent plate to respectively form an inlet manifold and an outlet manifold for the coolant.   3. Heat exchanger according to claim 1 or 2, characterized in that the sealing means consist of at least one partition (42) disposed between the inlet manifold and the outlet manifold of the cooling fluid.   4. Heat exchanger according to claim 3, characterized in that the partition (42) has a U-shaped section. 5. Heat exchanger according to claim 1 or 2, and characterized in that the sealing means are constituted by a partition (44) having a U-shaped section mounted outside of an exchange part of heat (2) along the short side of the plates (8) comprising the inlet and outlet manifolds (18) of the coolant.   6. Heat exchanger according to one of claims 1 or 2, characterized in that the sealing means consist of a fallen edge (48) formed at the periphery of the bosses (18) of the plates (8), this fallen edge extending at least from the turbulence generator (32) to the envelope (4).   7. Heat exchanger according to claim 2, caracté15 risé in that the sealing means are constituted by a stamped (50) formed between the two bosses (18) of a plate.   8. Heat exchanger according to one of claims 1 to 7, characterized in that it is produced in the form of a charge air cooler.