WO2008025617A1

WO2008025617A1 - Housing for the distribution of a heat-carrier fluid for a heat exchanger and heat exchanger comprising such a housing

Info

Publication number: WO2008025617A1
Application number: PCT/EP2007/057603
Authority: WO
Inventors: Patrick Boisselle; Gérard Gille; Erwan Vigneras
Original assignee: Valeo Systemes Thermiques
Priority date: 2006-08-31
Filing date: 2007-07-24
Publication date: 2008-03-06

Abstract

The invention relates to a housing (10) for the distribution of a heat-carrier fluid in a heat exchanger comprising a plurality of tubes (51) for circulating the fluid in the exchanger. The distribution housing comprises a fluid collection casing (11) provided with openings (31) for receiving the circulation tubes and said fluid collection casing (11) is made in a single piece of plastic material. The invention also relates to a heat-exchanger comprising such as distribution housing. Applicability: heat-exchangers in automotive vehicles.

Description

Housing for dispensing a heat transfer fluid for a heat exchanger and heat exchanger comprising such a housing

The present invention relates to a distribution box for a heat transfer fluid for a heat exchanger.

The invention finds a particularly advantageous application in the field of heat exchange systems in motor vehicles, including engine cooling radiators.

Heat exchangers for motor vehicles are known today consisting of a bundle of tubes arranged in parallel on one or more rows, these tubes being intended for the circulation through the exchanger of a coolant, such as water. added with glycol in the case of engine cooling radiators. The water cooling the engine components heats up and must in turn be cooled. It is the role of the radiator to perform this function. For this purpose, the water to be cooled is circulated in the tubes of the radiator and is cooled by heat exchange with air, the heat exchange being effected by means of heat exchange elements arranged in the bundle of tubes.

According to the assembly technology of the heat exchanger, different types of heat exchange elements are distinguished,

When the assembly is mechanical, the heat exchange elements are parallel fins traversed by the circulation tubes in holes formed in the fins. The maintenance of the assembly is carried out mechanically by means of a tool inserted inside the tubes so as to deform the walls of the tubes and forcefully apply them against the holes made in the fins.

Another assembly technology is the brazing of the tubes on heat exchange elements consisting of spacers placed between the tubes. In general, these spacers are made in the form of a corrugated surface, the tubes being brazed on the spacers at the vertices of the corrugations.

The coolant is introduced into the circulation tubes via a distribution box disposed at the inlet of the tubes and provided with a fluid inlet manifold. A housing of the same type, which will also be referred to as a distribution box, is installed at the outlet of the exchanger to collect the fluid after passing through tubes and evacuate outside through a tube of exit. Typically, the fluid distribution housing consists of two parts, namely a fluid collection box, often referred to as a "water box" in the case of radiators, and a collector element. The collector element is a part in contact with the tube bundle and carries openings for receiving the end of the tubes opening into the distribution box. The manifold forms a lid for the collection element and defines a volume of fluid in circulation at the inlet and at the outlet of the exchanger. It is in the manifold that opens the inlet manifold or fluid outlet.

Heat exchangers are known where the plastic fluid collecting boxes are of U-shaped open form, the collector member closing the U is by crimping, or by welding in the case where the collector is also plastic.

However, the distribution boxes made by welding a header and a collector member plastic have some disadvantages. In addition to the fact of the implementation of a different mold for each part, this technique requires rework at the weld, and the sealing of the distribution box is related to the quality of the weld performed.

It is to overcome these drawbacks that the invention proposes a heat transfer fluid distribution box for a heat exchanger comprising a plurality of fluid circulation tubes in the heat exchanger, said distribution box comprising a collection box of fluid having orifices for receiving the circulation tubes. The fluid collection box consists of a single piece of plastic material.

Thus, the embodiment of the distribution box according to the invention uses only one mold instead of two in the prior art. Moreover, the tightness of the housing is guaranteed because of the monoblock nature of its design, and no recovery of any order is necessary.

With the known housings, there is also the problem of resistance to rotation of the fluid collecting boxes with respect to the tubes of the bundle, particularly in the case where the bundle is single-rank, that is to say comprises only one row of tubes as opposed to the two-row bundle where the tubes are aligned in two parallel rows.

Indeed, during a rotation of the manifold, the resulting torque is applied to the tube to a height equivalent to that of the seal between the collector element and the tube. This height being low, the force exerted on the tube is relatively important.

On the other hand, this torque resulting from a rotation of the manifold applies to the tube over a distance equal to the diameter of the tube at the seal, which explains that the force exerted on the tubes is larger in the case of a single row beam than in the case of a two-row beam.

It is to limit these effects that the invention provides an embodiment in which the manifold includes lateral lips for gripping heat exchange elements subject to said tubes.

As seen above, said heat exchange elements are parallel fins traversed by said tubes, in the mechanical assembly mode, while said heat exchange elements are corrugated interlayers arranged between said tubes, in the solder assembly mode.

According to the invention, the seal between the manifold and the tubes is achieved because the manifold comprises at least one seal intended to be introduced into at least one orifice.

It is understood that, if the height of the lateral lips is greater than the height of the joints, for example a height equivalent to a few wings, typically 4 to 5, a rotation of the manifold will exert a torque which will be distributed over a larger area than with the known housings, hence a decrease in the force applied to the tubes. Furthermore, in the invention, the torque resulting from a rotation of the manifold applies to the tube over a distance equal to the width of the fins for example, therefore greater than the diameter of the tubes, with the advantage of decreasing This advantage may be further increased if, as provided by the invention, said orifices are oval to receive oval circulation tubes, in which case the distance over which the pressure is exerted is the rotational force is the width of the fins, which is greater than in the prior art, the major axis of an oval tube being greater than the diameter of a circular tube of equivalent section.

This arrangement also has the advantage of making beams having a greater number of tubes along the length of the fins.

The presence of lateral lips offers many other advantages. The guidance of the beam during assembly of the exchanger is facilitated by engagement of the fins between the lips. In addition, these lips can protect the connection between the tube bundle and the collector box against external aggression. In addition, aesthetically, the docking area between the fins and the seal is hidden by the side lips. Finally, the proposed solution makes it possible to envisage a connection between the beam and the casing made by coating, the lips defining a confinement volume of the bonding product.

When the manifold has a plastic tubular sleeve shape, it is necessary to place caps at the ends in order to close the volume of the box, because the manufacture by molding of this type of manifold involves the use of a core introduced and removed by one or both ends of the tubular sleeve form.

The commonly used plug closure techniques for plastic manifolds are screwing and welding. Screwing involves the realization of threads in plastic parts, quite difficult and expensive in terms of tools and assembly. In addition, the screwing requires to have a sufficient thickness of material to implant the thread. The pieces sold by plastic welding often include beads of surplus material ensuring the guarantee of a good fusion of parts, but offering an unsightly appearance.

To solve these difficulties, the invention proposes that said fluid collection box comprises a tubular sleeve closed at least at one end by a plug fixed to said sleeve by confined welding.

According to another embodiment, said fluid collection box comprises a tubular sleeve closed at least at one end by a plug fixed to said sleeve by clipping. The invention also relates to a heat exchanger, which is remarkable in that it comprises at least one a heat transfer fluid distribution box according to the invention.

In general, on the prestressed assemblies, the heat exchangers with tubular collector boxes must be equipped with crosspieces or lateral cheeks whose function is to connect together the two fluid inlet and outlet manifolds, in order to eliminate any risk of loosening tubes with seals during pressurization of the tube bundle. The cross or side cheeks ensure the longitudinal maintenance of the boxes relative to the tubes of the beam. According to an embodiment for simplifying the assembly of the heat exchangers according to the invention, at least some of the circulation tubes are flared at their end located inside said distribution box. Thus, the flaring of the protruding ends of the tubes in the manifold, after assembly of the tubes in the joints, makes it possible to block the longitudinal displacement of the tubes and to ensure retention of the bundle and the manifolds without the use of crosspieces or to lateral cheeks.

The following description with reference to the accompanying drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be achieved.

Figure 1 is an exploded perspective view of a fluid distribution housing according to the invention.

Figure 2 is a sectional view of the housing of Figure 1. Figure 3 is a sectional side view of the housing of Figure 2 along the HI-III axis.

Fig. 4 is a partial side sectional view of a first embodiment of a manifold end plug. Figure 5a is a partial cross-sectional side view of a second embodiment of a manifold end plug.

Figure 5b is a variant of the embodiment of Figure 5a.

Figure 6 is an exploded perspective view showing the arrangement of the housing, provided with a seal and tubes. Figure 7 is a perspective view showing a detail of the seal.

Figure 8 is a sectional view corresponding to Figure 7 to better show some characteristics of the seal.

Figure 9 is a perspective view of a fluid distribution housing according to a second embodiment of the invention. Figure 10 is an exploded perspective view showing the arrangement of the housing, provided with a seal and tubes according to the second embodiment.

Fig. 11 is a perspective view showing the arrangement of the housing, provided with a seal and tubes after mounting and according to the second embodiment.

In Figure 1 is shown a housing 10 for dispensing a coolant in a heat exchanger, such as a radiator.

Said heat exchanger comprises a plurality of tubes, such as the tube 51 initiated in Figure 1, placed parallel to each other in a row. These tubes are designed to circulate the heat transfer fluid, for example brine, through the heat exchanger.

The dispensing box 10 of FIG. 1 comprises a tubular shaped fluid collecting box 11 whose ends are closed by at least one stopper, not shown in FIG. 1, but which will be described below with reference to FIGS. 4, 5a. and 5b. The manifold comprises a part 12 called "collector part". This part has two faces: one located inside the volume of the manifold box 11 and another located outside of this volume. The collector portion 12 is of substantially planar shape at least on its outer face, that is to say the face in contact with a sealing ply 41 which will be described later. This part 12 has a plurality of orifices 31 for receiving the tubes 51 of circulation. Advantageously, the tubes 51 and the orifices 31 corresponding are oval, which allows to have a number of tubes per row greater than with round tubes.

As indicated in FIG. 1, the dispensing casing 10 forms a single one-piece piece made by injecting plastic into a single mold. The manifold 11 of fluid has the shape of a tubular sleeve obtained by demolding one or more cores along the longitudinal axis. The tubular sleeve section here is circular, but it could also be ovoid or even rectangular.

The seal between the manifold 11 and the tubes 51 is made by means of a ply 40 of individual seals 41 inserted into the corresponding orifices 31 of the header box. More precisely, the insertion is done at the level of the collector part 12.

It can be seen in FIG. 1 the presence of lateral lips 21, 22 molded at the same time as the manifold 11. The functions of these lateral lips appear more clearly in FIG. 2.

According to Figure 2, the lateral lips 21, 22 are intended to grip a number of fins 60 placed parallel to each other and perpendicular to the tubes 51. For this purpose, the fins 60 are pierced with holes for the passage of the tubes 51 , the number of holes being equal to the number of tubes of a row. These fins are heat exchange elements between the tubes 51 and air flowing between the fins in the direction indicated by the arrow F. This type of heat exchange elements is well suited to mechanically assembled heat exchangers. However, other heat exchange elements may be considered, such as corrugated dividers used for brazed heat exchangers.

FIG. 2 shows that if the lateral lips 21, 22 have a height H exceeding that of the joints 41, for example 4 to 5 fins, the force exerted on the bundle of tubes by the rotation of the box 11 is smaller. that if this effort was exerted on the height of the joint, as for the known cases of the prior art.

Similarly, it can be seen in Figure 2 that the torque is applied to a distance L equal to the width of the fins 60, this distance being all the greater as oval tubes 51, and not round, are used .

Another advantage of the lateral lips 21, 22 is to facilitate assembly of the tube bundle and the housing 10 by centering effect on the width of the fins. FIG. 3 illustrates a particular embodiment of a heat exchanger comprising a distribution casing 10 as previously described, in which the ends of the tubes 51 opening into the manifold 11 are flared, so as to block the longitudinal displacement of the tubes by relative to the housing, Applying the same arrangement for the other housing of the exchanger, it avoids the use of rails or side flanges to connect the two housings together.

An embodiment not shown proposes a selective flaring of the tubes. In other words, only a part of the tubes, placed in selected places, will be flared. One can, for example, choose to flare that the first tubes located at each end of the beam, for example between four and ten tubes. A particular embodiment provides for the flaring of the first five or six tubes on each side of the beam.

FIG. 4 shows a proposed solution for sealing the ends of the tubular sleeve constituting the manifold box 11. This solution consists of welding without a visible bead a plug 13 of plastic material by vibrations, vibrations or even friction when the plug is cylindrical.

Welded plugs allow sealing without the use of rubber seals, with cycle times shorter than one second. The weld seam 70 is invisible because it is confined in the collecting box thanks to the shapes of the plug 13 which prevent the excess material from overflowing to the outside. It is not necessary to have a surplus of material to ensure the welding because it is carried out in the longitudinal direction of the box,

FIGS. 5a and 5b show two modes of closing the header 11 by clipping a plug 13 ', 13 ". This type of non-welded mounting requires the use of an O-ring.

80, the plug is then clipped onto suitable profiles of the ends of the box 11. The closing of the volume of the header is very fast, the clipping takes a few seconds.

The clipped caps make it possible economically to close the boxes with a limited investment in assembly means.

Figure 6 shows how the seal can be mounted outside the manifold. It is seen that the seal comprises, as already indicated, a web 40 supporting a plurality of individual seals 41 in the form of a sleeve. In the example, the tubes have a section of substantially oval shape and the individual seals are made in the form of a sleeve of homologous shape. From the outside of the housing 10 are issued two parallel walls 21 and 22, also called lips, which serve to frame the web of the seal. As can be seen in FIG. 7, each individual seal comprises outer lips 56 which serve to hold the seal in place on the manifold after interlocking thereof in the passage holes of the tubes and an anti-dislocation thereof. after threading the tubes. These outer lips protrude inside the collector box once the seal has been put in place.

It can be seen in FIG. 8 that this seal further includes inner lips 58 which project inwardly from the individual seal, that is to say towards the inside of its sleeve. These inner lips serve to improve the tightness of the end of the tube because the pressure inside the manifold will exert a force on the lip and increase the contact on the tube. They also serve to lock the outer lips. Figures 9; 10 and 11 show a fluid distribution box according to a second embodiment of the invention.

In this embodiment, the dispensing box 10 comprises two sets of holes or orifices 31 -A and 31 -B which are intended to receive two rows of circulation tubes 51-A and 51 -B. The distribution box 10 is here a so-called dual-row distribution box.

As in the previous embodiment (that is to say a heat exchanger comprising a single row of tubes), the dispensing casing 10 comprises a tube-shaped fluid collecting box and a so-called "collecting portion" portion.

The collector portion has two faces: one located inside the volume of the collector box and another located outside this volume. The collector portion is flat and this at least on its outer face, that is to say the face in contact with a ply of joints 40 (shown more particularly in Figure 10). The collector portion has a plurality of orifices 31 -A and 31 -B for respectively receiving the tubes 51 -A and 51 -B. The orifices 31 -A and 31 -B are divided into two rows of holes parallel to each other, the holes of a row being located one below the other. The dispensing case 10 is closed at its ends by at least one plug 13.

Here too, the dispensing casing 10 forms a single piece piece made, for example, by plastic injection in a single mold.

The dispensing casing 10 further comprises two lateral lips 21, 22.

The housing is provided with a ply of seals 40 which is applied, in this embodiment, to the manifold portion of the distribution housing 10 between the two lateral lips 21 and 22. The ply of joints 40 is composed of two parallel series of individual joints that will receive after assembly the two rows of tubes 51-A and 51 -B. Each individual seal is composed of at least one sleeve inserted in an orifice of the distribution box to allow a seal between the distribution box and the circulation tubes. The heat exchanger also has fins 60 placed parallel to each other and perpendicular to the tubes 51-A and 51-B (only one of them has been shown in Figures 10 and 11). The fins 60 are pierced with two rows of holes allowing passage of the two rows of tubes 51 -A and 51-8, the number of holes in each row being equal to the number of tubes of said row.

In this embodiment, the ends of the tubes 51-A and 51-B have been ovalized. This operation consists, with the aid of a specific punch called ovalization, to change the shape of the tubes at at least one of these ends, here the tube comprises, before the ovalization operation, a general shape outline of the "bean" type.

This ovalization operation is performed after the expansion operation of the tubes in the fins. The main purpose of this operation is to give resistance to the tube against the compression of the seal on the tube. In fact, a form of obiongue or oval type withstands external pressure better than a bean-like shape. It also improves the internal pressure drop of the liquid by increasing the inlet section of the tube.

An embodiment not shown provides an exchanger comprising a bundle of tubes and fins brazed together on which is placed a distribution box according to the invention.

Claims

1. housing (10) for dispensing a heat transfer fluid for a heat exchanger comprising a plurality of tubes (51) for circulating the fluid in the exchanger, said dispensing box comprising a manifold (11) of fluid having orifices (31) for receiving circulation tubes, said manifold (11) of fluid consisting of a single piece of plastic material,

The housing of claim 1, wherein said housing comprises two series of orifices (31-A; 31 -B) for receiving two rows of circulating tubes (51-A; 51-B), said two series of orifices (31-A; 31-B) are divided into two rows of holes parallel to each other, the holes of one row being located one below the other.

3. Housing according to claim 1 or 2, wherein said manifold (11) comprises side lips (21, 22) for gripping elements (60) for heat exchange subject to said tubes (51).

4 housing according to one of claims 1 to 3, wherein the manifold (11) comprises at least one seal (41) to be introduced into at least one orifice (31).

5. Housing according to the preceding claim, wherein the height of the lateral lips (21, 22) is greater than the height of the joints (41).

6. Housing according to one of the preceding claims, wherein the manifold (11) comprises a collector portion (12), at least one of the faces of said collector portion (12) being substantially planar.

7. A casing according to any one of the preceding claims, wherein said fluid casing (11) consists of a tubular sleeve closed at at least one end by a plug (13) fixed to said sleeve by confined welding.

8. Housing according to any one of claims 1 to 6, wherein said fluid manifold (11) consists of a tubular sleeve closed at least one end by a plug (13 ', 13 ") attached to said sleeve by clipping .

9. Heat exchanger, characterized in that it comprises at least one housing (10) of coolant distribution according to any one of the preceding claims.

10. Heat exchanger according to the preceding claim taken in its connection to one of claims 3 to 8, wherein said heat exchange elements are fins (60) parallel traversed by said tubes.

11. Exchanger according to any one of claims 9 and 10, wherein at least a portion of the tubes (51) of circulation are flared at their end located inside said housing (10) distribution.