EP1058807A1

EP1058807A1 - Heat exchanger with flexible tubes

Info

Publication number: EP1058807A1
Application number: EP99961164A
Authority: EP
Inventors: Carlos Manuel Martins; Laurence Marechal
Original assignee: Valeo Thermique Moteur SA
Current assignee: Valeo Thermique Moteur SA
Priority date: 1998-12-29
Filing date: 1999-12-23
Publication date: 2000-12-13
Anticipated expiration: 2019-12-23
Also published as: US6390187B1; EP1058807B1; FR2787873B1; FR2787873A1; WO2000039517A1; JP2002533655A; DE69905862D1; DE69905862T2

Abstract

The invention concerns a heat exchanger (2) with flexible tubes (20), particularly for a motor vehicle cooling installation. The tubes (20), for example made of a plastic material, are designed to carry a heat-exchanging fluid capable of co-operating with an air stream circulating through the exchanger (2). The inventive exchanger (2) comprises means for maintaining the tubes (20) in parallel rows. The tubes (20) are designed to be generally shaped like substantially sinusoidal lines. The sinusoids of two contacting tubes (211, 212) of two consecutive rows, are phase offset relatively to each other such that the two tubes (211, 212) are maintained in two contact zones (210) per sinusoid interval, thereby leaving interstices between the tubes (20) to enhance the penetration of the flux.

Description

FLEXIBLE TUBE HEAT EXCHANGER

The present invention relates to the field of heat exchangers, in particular for cooling installations of motor vehicle engines. It relates more particularly to heat exchangers with flexible tubes, for example made of plastic.

Such heat exchangers, described in particular in the unpublished French Patent Application No. 98 04966 of the Applicant, include tubes made of a substantially flexible material and the ends of which communicate with at least one manifold of a fluid of heat exchange, cooperating for example with an air flow which passes through the exchanger.

In order to increase the thermal cooperation of the flow with the tubes of the exchanger, it is currently desired to maintain interstices between the tubes, through which the air flow penetrates. Such interstices would also make it possible to disturb the flow in the manner of the disturbing fins that usually include heat exchangers with rigid tubes.

The present invention then improves the situation.

It relates to a heat exchanger with flexible tubes, of the aforementioned type which comprises, according to a general characteristic of the invention, means for holding the tubes in substantially parallel rows. The tubes are shaped to have general shapes of substantially sinusoidal lines. The sinusoids of two tubes in contact, of two respective consecutive rows, are substantially offset from one another, one part relative to the other, so that the two tubes are held in two contact zones per period of sinusoids. Preferably, the sinusoids of the respective tubes of two consecutive rows are substantially in phase opposition, while the sinusoids of the same row are in phase.

According to another optional feature of the present invention, the contact zones of the respective tubes of consecutive rows are substantially inscribed in a plane perpendicular to the rows.

Advantageously, the spacing between the rows is substantially constant.

According to another advantageous characteristic of the invention, at least part of the external surface of the tubes, comprising the abovementioned contact areas, is coated with a layer of adhesive to form means for holding the tubes.

In a preferred embodiment of the present invention, the outer surfaces of the tubes carry a material made adhesive by vulcanization treatment, thus forming the above-mentioned adhesive layer.

In a more elaborate embodiment of the invention, the holding means further comprise a plurality of rods substantially perpendicular to the rows and each installed between the respective sinusoids of consecutive rows, to keep the tubes of the consecutive rows substantially spaced apart.

Other advantages and characteristics of the present invention will appear on reading the detailed description below and the appended drawings, in which:

FIG. 1 schematically represents a partial view of a device for cooling the engine of a motor vehicle in the example described, FIG. 2 represents a schematic view of a heat exchanger, in particular of a cooling radiator 2 of a device shown in FIG. 1,

FIG. 3A represents the tubes of a heat exchanger according to the present invention, shaped according to lines of substantially sinusoidal shape,

FIG. 3B represents, in a front view, the tubes of FIG. 3A,

FIG. 3C is a view along section C-C of FIG. 3B, in the section plane of the tubes,

FIG. 3D is a view along the section D-D of FIG. 3B,

FIG. 3E is a side view of the tubes of FIG. 3A,

FIG. 4A represents the tubes of a heat exchanger, provided with parallel rods,

FIG. 4B is a top view of the tubes of FIG. 4A, and

- Figure 4C is a side view of the tubes of Figure 4A.

The attached drawings essentially contain elements of a certain nature. They can not only serve to better understand the present invention but also contribute to its definition, if necessary.

First of all, reference is made to FIG. 1 to describe a device for cooling a motor vehicle engine.

Such a device comprises, in a manner known per se, a motor-fan unit 1 provided with a plurality of blades. The fan motor unit 1 is usually placed behind the grille of the vehicle (not shown). A heat exchanger heat according to the invention is interposed in an air flow (arrows F) produced by the rotation of the blades of the motor-fan unit 1, or even the movement of the vehicle itself. In practice, the heat exchanger is supplied by the engine coolant, usually under the control of a thermostatic valve 3. The arrangement of such a valve in the coolant circuit 4 generally makes it possible to obtain satisfactory performance of the engine M when it is started cold, by cutting off the power to the radiator.

Reference is now made to FIG. 2 to describe the structure of the heat exchanger 2 (cooling radiator, in the example). This heat exchanger comprises flexible tubes 20 (represented by hatching in FIG. 2), generally made of a plastic material, which communicate by their ends with two manifolds 21 and 22. In fact, the manifolds are provided with openings 215 and 225 closely accommodating the ends of the tubes 20. In practice, the boxes comprise manifold plates provided with the openings 215 and 225, and which thus form means for holding the tubes, in particular their ends.

The manifolds 21 and 22 usually have compartments 210, 211, 212 and 221, 222, separated by partitions 213, 214 and 223, respectively, to define a path of the aforementioned heat exchange fluid (coolant in the example described), between an inlet C (arrow E) which communicates with an inlet duct 23 and an outlet (arrow S) which communicates with a discharge duct 24. In the example shown in FIG. 2, the boxes manifolds have a total of five compartments and the heat exchange fluid performs a total of three "outward" routes and two "return" routes from the manifold 21 to the manifold 22.

The fluid paths between the two manifolds 21 and 22 are then provided by the tubes 20, in which circulates the fluid. Thus, the tubes cooperate thermally with the air flow F. However, to optimize the heat exchange between the tubes 20, on the one hand, and the air flow F, on the other hand, it is necessary to maintain the tubes substantially spaced from each other to create gaps between them.

Reference is then made to FIGS. 3A to 3E to describe the set of tubes of a heat exchanger according to a first embodiment of the present invention.

According to a general characteristic of the invention, the tubes 20 of the exchanger are arranged in rows 20A horizontal in the example described (Figure 3E). These rows are substantially parallel to each other and spaced, in the example described, by a distance corresponding substantially to a thickness of tube 20, so that the different rows are substantially adjacent by pairs of respective tubes of two consecutive rows , substantially in contact with each other.

Referring to FIG. 3A, it appears that the tubes generally have generally substantially sinusoidal shapes. The tubes 211, 212 of the same row 20A have their sinusoid substantially in phase. Referring to FIG. 3B, it appears that two tubes 211, 212 in contact, of two consecutive consecutive rows, are in phase opposition and are in contact on areas 210 corresponding to nodes of the two sinusoids.

Figure 3C shows a sectional view (section plane of the tubes) of the nodes of the aforementioned sinusoids. The tubes of the same row 20A are substantially separated from each other, since the sinusoids of the same row are in phase, while the tubes of two consecutive rows are in contact at the level of the zones 210 (nodes of the sinusoids).

Figure 3D is a sectional view (section plane of the tubes) of the bellies formed by the sinusoids of the tubes of the rows consecutive. A difference then appears between two tubes of two consecutive rows, respective, since the sinusoids of the two tubes are in phase opposition from one row 20A to the other, consecutive.

As shown in FIG. 3C, the contact areas 210 between the tubes of consecutive rows are inscribed in substantially horizontal planes, while the rows 20A are arranged in substantially vertical planes. Thus, the contact areas 210 of the respective tubes of consecutive rows are substantially inscribed in planes perpendicular to the rows 20A.

Preferably, the tubes are made of a plastic material made adhesive by a heat treatment. Thus, after hot treatment, the tubes are mechanically connected to each other by gluing, in their contact zones 210.

As a variant, provision may be made to coat the external surfaces of the tubes with a material having such a property, or else with a layer of adhesive to form the aforementioned holding means. In particular, glue dots arranged on the contact areas 210 are sufficient to maintain the tubes in rows 20A, and substantially fixed with respect to each other. It should be noted that the openings of the manifolds are themselves arranged in rows and columns to immediately maintain the ends of the tubes in rows.

Reference is now made to FIGS. 4A to 4C to describe the arrangement of the tubes of a heat exchanger according to a second embodiment of the present invention.

As in the first embodiment described above, the tubes of the same row 20A form sinusoids substantially in phase, while tubes of two consecutive rows form sinusoids in phase opposition. In this embodiment, there are further provided rods 213 substantially parallel to each other and perpendicular to the rows 20A. Each of these rods is inserted into the bellies formed by the sinusoids of the tubes of consecutive rows, as shown in Figure 4B. Such rods 213 thus make it possible to keep the tubes substantially apart in the consecutive rows. Consequently, it is not necessary to provide here an adhesive coating on the tubes, in particular on the contact areas 210. However, it can also be provided to provide the external surfaces of the tubes and, in particular, the external surfaces rods of a layer of glue or of a coating rendered adhesive by heat treatment, for example by vulcanization, to reinforce the maintenance of the tangled row tubes, as shown in FIGS. 3A and 4A.

Thus, the spacing between the tubes, in particular in the sinusoid bellies, allow the air flow F to enter the exchanger, while advantageously disturbing the flow F. Furthermore, the flexible tubes of the exchanger are generally of small diameter, typically about 1 to 4 mm and with a wall thickness close to 0.2 mm. It is then desired to maintain the tubes in a substantially rigid structure by their arrangement in sinusoids described above, with a view to protecting them with respect to the constraints of use (vibrations, aging of the material, pressure of the heat exchange fluid, etc.) which tend to weaken them. Another advantage provided by the present invention then consists in that the tubes are held fixedly with respect to each other.

Preferably, the period of the sinusoids is in a range of 40 to 80 mm and their amplitude, relative to a general axis of the tube, is between half a tube diameter and two tube diameters. With particular reference to FIG. 3A, the ends of the tubes are contiguous and flat over a length of approximately 5 to 25 mm, so that they can be connected to the manifold, while the total length of the tubes is, for example, of around 500 mm. Of course, the present invention is not limited to the embodiment described above by way of example. It extends to other variants.

It will thus be understood that the sinusoids of the tubes of the same row are not necessarily in phase. As a variant, it can in fact be envisaged to have the tubes of the same row sufficiently spaced apart, while the phases between their sinusoid are substantially random.

Furthermore, the adjacent tubes of two consecutive rows are not necessarily in phase opposition. Indeed, it suffices to offset the two sinusoids in phase to allow an air flow to enter between the tubes. However, the arrangement of the two sinusoids in phase opposition allows maximum penetration of the air flow by the bellies which they form.

In the example described above, the rows are substantially horizontal, while the contact areas 210 are arranged substantially in vertical planes. More generally, these planes are not necessarily perpendicular to the rows, in particular if the adjacent tubes between consecutive rows are offset laterally from one row to the other.

The aforementioned means for holding the tubes (adhesive film, coating made adhesive by heat treatment, spacer rods 213) are described above by way of example. Other holding means can be envisaged.

Furthermore, in the example shown in FIG. 2, the exchanger 2 comprises two manifolds. As a variant, it may be provided only for a manifold provided with openings into which the ends of the tubes are introduced, while each tube has a "U" shape, the two branches of which are wavy and inscribed in a same row, or interlaced, while each branch of "U" is registered in a separate row. Finally, the heat exchanger described above by way of example is intended to operate as a radiator for cooling a motor vehicle. As a variant, this heat exchanger can be provided as a heating radiator housed in a hot air branch of a ventilation, heating and / or air conditioning installation of the passenger compartment of the vehicle, or even as an evaporator. an air conditioning loop of this installation, or other. Furthermore, the fluid passing through the heat exchanger (air flow F in the example described above) may be of a different nature, for example oil, in particular for an application of the exchanger as engine oil cooler.

Claims

claims

1. Heat exchanger, in particular of a cooling installation of a motor vehicle engine, of the type comprising a plurality of tubes (20) made of a substantially flexible material, and intended to convey a heat exchange fluid specific to cooperate with a flow of fluid (F) passing through the exchanger, characterized in that it comprises means for holding the tubes in substantially parallel rows (20A), and in that the tubes (20) are shaped to have shapes lines of substantially sinusoidal lines, while the sinusoids of two tubes (211,212) in contact, of two respective consecutive rows, are substantially offset in phase relative to each other so that the two tubes are held in two zones of contact (210) by period of sinusoid.

2. Exchanger according to claim 1, characterized in that the sinusoids of the respective tubes (211,212) of two consecutive rows, are substantially in phase opposition, while the sinusoids of the same row (20A) are in phase.

3. Exchanger according to claim 2, characterized in that the contact zones (210) of the respective tubes of consecutive rows are substantially inscribed in a plane perpendicular to the rows.

4. Exchanger according to one of the preceding claims, characterized in that the spacing between the rows (20A) is substantially constant.

5. Exchanger according to one of the preceding claims, characterized in that at least part of the external surfaces of the tubes, comprising said contact areas (210), is coated with a layer of adhesive to form means for holding the tubes.

6. Exchanger according to claim 5, characterized in that the external surfaces of the tubes (20) carry a material made adhesive by heat treatment.

7. Exchanger according to one of the preceding claims, characterized in that the holding means comprise a plurality of rods (213) substantially perpendicular to the rows (20A) and each implanted between the respective sinusoids of consecutive rows, to hold the tubes ( 211,212) of the consecutive rows substantially apart.

8. Exchanger according to one of the preceding claims, characterized in that it comprises at least one manifold (21,22) provided with openings (215,225) each communicating with one end of a tube, and arranged to house tightly the ends of the tubes by forming means for holding the ends of the tubes.

9. Exchanger according to one of the preceding claims, characterized in that the period of the sinusoids is between 40 and 80 mm.

10. Exchanger according to one of the preceding claims, characterized in that the amplitude of the sinusoids, relative to a general axis of the tube (20), is between a half tube diameter and two tube diameters.

11. Exchanger according to one of the preceding claims, characterized in that the ends of the tubes (20) are contiguous and flat over a length of approximately 5 to 25 mm.