GB2054125A

GB2054125A - Tubular heat exchanger

Info

Publication number: GB2054125A
Application number: GB8021060A
Authority: GB
Original assignee: Valeo SE
Current assignee: Valeo SE
Priority date: 1979-06-29
Filing date: 1980-06-27
Publication date: 1981-02-11
Also published as: FR2460467B1; IT8067990A0; DE3023496A1; FR2460467A1; ES251765Y; JPS5610698A; ES251765U; IT1129101B

Abstract

In a heat exchanger of the type having parallel tubes for the primary fluid, for example water, with fins to be swept by a secondary fluid, for example air, the tube ends extending through and being fixed to a header plate associated with a water box to form a header, the co-planar fin edges are capped by a crosspiece 31 to maintain them in assembly, there being at each end of the crosspiece 31 a connector piece 42 which is integral with the crosspiece e.g. by these parts being welded together, and which is constructed to contribute to the rigidity of the assembly and to the fluid tightness of the joint between the header plate 13 (or 14) and the rim 71 of the water box. A ridge or bar 39 projects from the cross-piece 31 for mounting the heat exchanger e.g. in a vehicle, or for attaching a component such as a motor-driven fan to the heat exchanger. <IMAGE>

Description

SPECIFICATION Heat exchanger The present invention relates to heat exchangers having a nest of parallel tubes through which a primary fluid, e.g. water, flows and which extend through and contact fins which are swept by a secondary fluid, for example air, the tubes being assembled at least one of their ends to a header plate which together with a water box bounds a header chamber.

Particularly for vehicles, one contrives to construct heat exchangers which are lighter without affecting their life, in spite of the sresses to which they are subjected due to vibrations and the pressure of the circulating water. In this respect problems arise not only of a mechanical nature but also relating to the fluid tightness of the heat exchanger.

With a view to increasing the mechanical strength of a heat exchanger as such, as well as of its mounting on a vehicle, it has been proposed to cap the co-planar edges of the fins with a structural part, or crosspiece, adapted to contribute to mounting the exchanger and also for cooperating in the mounting of other components of the vehicle, notably of the motor driven fan assembly provided for cirulating the secondary fluid through the exchanger.

In an exchanger comprising at least one such crosspiece capping the co-planar edges of the fins, the crosspiece is extended at either of its ends so as to be assembled to the header plate and to form a bracing for the water boxes.

By providing a heat exchanger with bracing crosspieces on the two long opposite sides of the tube nest, one obtains a construction of almost absolute rigidity, the two other sides being formed by the water boxes.

The fact of conferring this rigidity to the assembly offers a particular advantage where the tubes of the nest extend at least through one holed plate without interposition of sealing joints, by relieving the ends of the tubes of their function of force transmission agents.

Thus according to the invention, the ends of the crosspieces are assembled to the header plates so as to assist the assembly of the water boxes and the header plates and also to the fluid tightness of the assembly.

For facilitating the production, the connection between the header plates and the crosspieces as such is carried out by means of connectors which are stamped and bent, and made integral with the crosspieces as such.

The invention is advantageously used in the case where the exchanger comprises a nest made of a single row of tubes, which makes it easily deformable.

In the following description which is given by way of example, reference is made to the accompanying drawings wherein Fig. 1 is an elevation of a heat exchanger according to the invention, Fig. 2 is a corresponding plan, Fig. 3 is a perspective view to a larger scale of a fin, Fig. 4 is a transverse sectional view of a crosspiece, Fig. 5 is an elevation to a larger scale of a part of the exchanger shown in Fig. 1.

Fig. 6 is a view to a larger scale of a portion of the exchanger shown in Fig. 2, Fig. 7 is a perspective view of an assembly piece, and Fig. 8 is a sectional view along line 8-8 of Fig.

2, but to a larger scale.

The heat exchanger comprises (Fig. 1 and 2) a nest 11 of parallel tubes 12 with their axes horizontal and arranged in a single row between a first header plate 13 and a second header plate 14 each of which is capped by a water box, respectively 15 and 16.

Fluid tightness at the points where the ends of the tubes 1 2 extend through a header plate is provided (Fig. 8) by sheet 81 of rubber or the like which also contributes to the provision of a fluid ftight joint between the header plate (such as a header plate 13 (in Fig. 8)) with the corresponding water box 1 5.

The primary fluid, which here is water, from a pump enters the water box 1 6 via an upper tube 17, and leaves the exchanger via lower tube 18 on the water box 1 5. At the upper part of the water box 15 an opening 19 is provided for filling the apparatus. The tubes 12 extend in contact with and through a stack 23 of fins 26 which in use are swept by a secondary fluid, here air, and the header plates 13, 1 4 are formed with protruding portions relative to the stack 23. The upper 25 and lower 29 horizontal edges of the fins 26 (Fig. 3) which have a rectangular contour bounded by the vertical edges 27, 28, are capped by crosspieces 31 (Figs. 1, 4 and 5) of general U-shaped crosssection, with a base 32 and side flanges 33, 34.

In one embodiment, the edges 28 and 27 of the fins are formed, in the vicinity of the edges 25 and 29, with notches 35 and 36 of triangular shape in which engage the bent edges 37 and 38 of the flanges 33 and 34, thereby conferring on the fins the function of giving the exchanger a good mechanical strength.

From the base 32 of each crosspiece 31 a ridge or bar 39 projects to provide for mounting the exchanger and/or attaching other components, such as a motor driven fan-blower assembly, to the exchanger.

Fixed at one end of the base 32 of the crosspiece 31, advantageously by welding, there is a connector 42 of generally angle section (Fig. 5 to 7) comprising a plane floor 43 the under surface 44 of which lies on and is welded to the upper surface 45 of the base 32. The connector 42 also has a plane wall 46 which is perpendicular to the floor 43 and has its side edges 47 and 48 more distant from each other than the width of the base 32, the width of the floor 43 being at its outer end 49, equal to the width of the base 32.

The connector 42 thus formed promotes torsional strength in the exchanger, particularly when, as in the embodiment shown, the tube nest comprises only a single row of tubes, the water boxes and the header plates being then wider than the tube nest.

The floor 43 is bounded by two wings 52 and 53 which are perpendicular to the floor. The wing 53 flares outwardly from its end 51 towards the wall 46 and the wing 52 flares outwards only in the vicinity of the wall 46. The upper edge 55 of wing 53 has an almost rectilinear portion 56 (Fig.

6) followed by a curved portion 57 extending into a further rectilinear portion 58 transversely to the medium line 59 of the crosspiece 31.The rigidity of the connector is increased by ribs 61 and 62 joining the floor 43 and the wall 46 and providing resistance against deformation of the angle formed therebetween.

The wall 46 has its free edge a flange 63 to overlie and contact the edge 64 of the header plate 13. The flange 63 extends to a downward flange 67 which is at right angles to the flange 63 and is thus parallel to wall 63. The downturned flange 67 comprises lugs 68 which engage in notches 69 between downturned lugs 66 on the collector 13 and therefore assist to strengthen the joint between the header plate 13 and the water box 15. The lugs 68 which bear on rim 71 (Fig. 5) of the water box promote the maintenance under pressure of the peripheral seal portion of the sheet 81 located between the header plate 13 and the water box 1 5 and thereby increase the fluid tightness of the assembly. An identical connector 42' is secured to the other end of the crosspiece 31.

The crosspiece 31 thus provided with connectors 42 and 42' forms a bracing between the header plates 1 3 and 14, The width of the surfaces 72 and 72' of edges 46 and 46' contacting the header plates (Fig. 7) contribute to a good bracing, walls 46, 46' also serving as extra supports when assembling the water boxes to the header plates.

The fluid tightness of the mounting of the water boxes 1 5 and 1 6 is thereby increased.

A similar disposition is foreseen at the lower part of the heat exchanger.

In an alternative embodiment, the lugs 66 may be omitted.

The invention applies also to heat exchangers the nests tubes of which are arranged in several rows. The part welded at the ends of the crosspieces may then have a constant width, depth or width of the header plates being then equal to the width of the tube nest.

It applies to heat exchangers with vertical tubes.

Claims

1. A heat exchanger with a nest of parallel tubes, in which flows a primary fluid, for example water, in contact with fins adapted for being swept by a secondary fluid, for example air, at least one end of the tubes being fixed to a header plate through which they extend, the header plate being capped by a water box and bounding with said box a header chamber, co-planar fin edges being capped by a crosspiece for maintaining them assembled, wherein at each end of the crosspiece, a connector piece which is integral with the latter contibutes to the assembly of the header plate and the water box as well as to the fluid tightness of the assembly.

2. A heat exchanger according to claim 1, wherein the end connector piece has a generally angle section with a floor which is welded to the crosspiece, and a wall perpendicular to the floor bearing against a protruding portion of the header plate.

3. A heat exchanger according to claim 2, wherein the wall has a flange overlying and contacting the edge of the header plate.

4. A heat exchanger according to claim 3, wherein the flange has a return flange, the header plate being held between the wall and the return flange.

5. A heat exchanger according to claim 4, wherein the return flange comprises notches and lugs.

6. A heat exchanger according to claim 5, wherein the lugs of the return flanges engage in notches between lugs on a flange on the header plate.

7. A heat exchanger according to claim 5 or claim 6, wherein the lugs bear against the rim of the water box.

8. A heat exchanger according to any of claims 2 to 7, wherein the floor has perpendicular wings to improve its rigidity:

9. A heat exchanger according to any of claims 2 to 8, wherein strengthening ribs are interposed between the floor and the wall.

10. A heat exchanger according to any of claims 2 to 9, wherein the floor has, at its free end, a width corresponding to that of the crosspiece, and the wall has a greater width.

11. An end piece of a crosspiece which is part of a heat exchanger according to any one of the preceding claims.

1 2. A heat exchanger substantially as hereinbefore described with reference to and as shown in the accompanying drawings.