EP1206672B1 - Heat exchanger and related exchange module - Google Patents

Abstract

A heat exchange module is disclosed comprising two metal sheets welded along weld lines defining between them a group of channels disposed side by side substantially in a common plane, intended to be passed through by an exchange fluid and, from the fluidic point of view, being in parallel with each other between two connection orifices of the module. The group of channels has a generally U-shape configuration, which connects together the said connection orifices that are laterally separated from each other.

Description

The present invention relates to a heat exchange module intended to form part of the thermally active bundle of a heat exchanger.

The present invention also relates to a heat exchanger equipped with such a module.

WO-A-98/16 786 describes an exchanger whose beam is constituted by a stack of bi-plate modules. Each module consists of two sheets defining between them a series of longitudinal and parallel channels leading a first exchange fluid from one end to the other of the modules. The method of producing such modules consists of laser welding two flat sheets along longitudinal and parallel lines intended to form the separations between the channels. A peripheral weld closes the space between the two sheets except for a nozzle for injection of water under pressure. The module is formed by injecting water under pressure between the two plates so as to produce a swelling of the two sheets between the weld beads.

The modules thus produced are stacked so that the outer surfaces of the neighboring modules are pressed against each other along the ridges of the channels. It thus forms between the modules other channels provided for the circulation of the second exchange fluid, in general against the current relative to the first exchange fluid.

This known heat exchanger is very efficient because it provides for the two exchange fluids the advantages of circulation in quasi-tubular channels, in particular with a reduced pressure drop.

Such exchangers can be used in particular in applications where the flow rates are very high, in particular in petroleum refineries, in particular for a petroleum fluid entering a treatment apparatus to be preheated with heat supplied by the fluid. treatment, so that the thermal cost of the treatment is limited to the contribution of a simple complement. Such exchangers can have a considerable size, of the order of 15 to 20 meters in height, the circulation of fluids being effected in the vertical direction to save floor space.

A construction of such a height entails high structural costs, for the mechanical stability, the thermal insulation with respect to the outside, and the fluid connections.

DE-A1-196 39 115 and GB-A-1 286 446 disclose plate-type exchangers in which two sheets are joined by welding beads defining ramifying channels. After branching, the resulting channels extend side by side along one or more 180 ° turns.

FR-A 589 212 discloses a cooling radiator module formed of two sheets joined by seam lines defining between them a group of channels having a loop configuration whose two ends facing each other are connected to two mutually adjacent manifolds.

The object of the invention is to allow the realization of heat exchangers much more compact than those of WO-A-98/16786, while being as efficient as these.

According to the invention, the heat exchange module intended to be part of a stack of such modules and comprising two sheets joined along lines defining between them a group of channels arranged side by side substantially in a common plane, intended to be traversed by an exchange fluid being fluidically in parallel with each other from one to the other of two module connection orifices, the group of channels having a generally U-shaped configuration which has a turn between two longitudinal branches and which connects one to the other said connection orifices, is characterized in that said lines fix the sheets to each other by welding and the connecting orifices are arranged to receive connection means laterally spaced one the other.

For the same developed length of the channels, the module according to the invention is half as long and thus allows, for example in a vertical application, to achieve a round of exchange roughly half as high. Compared to such a saving in height, the slightly increased footprint is a negligible disadvantage. It is even noted that the tower, being both less high and larger base area, is therefore much more stocky, so naturally stable mechanically.

The advantages of the invention are not limited to tower-type exchangers. For example, an exchanger according to the invention is particularly advantageous when the second fluid circulates between the modules transversely to the branches of the U. Thanks to the invention, each net of one of the exchange fluids meets twice in succession, and no more than once, the path followed by a net of the other exchange fluid.

The invention is not limited to a U-shaped configuration. It is conceivable for the channels to be extended by a third longitudinal branch connecting to one of the two preceding ones by a second 180 ° turn in the opposite direction to the first, And so on.

When the number of branches is even, and in particular when it is two, one of the important advantages that is obtained is that all the fluidic connections are grouped at one end of the exchanger. In particular, in the tower arrangement, all the fluidic connections can be grouped at the base of the tower. This simplifies the realization of the exchanger and reduces the cost.

An important aspect of the present invention is also to have improved the path of the first exchange fluid at each of its ends in the modules. The difficulty is to distribute the first exchange fluid as equitably as possible without forming at the end of the channels an area which would be mechanically unstable, for example not very resistant to pressure, or on the contrary mechanically too stable and which would prevent, for example, during hydroforming, the correct swelling of the channels near their ends.

According to this aspect of the invention, the heat exchange module comprising two sheets welded along welding lines defining between them a group of channels arranged side by side substantially in a common plane, intended to be traversed by a fluid of exchange fluidly in parallel with each other between two connection ports of the module, is characterized in that from a longitudinal region the channels have a convergent region which curves towards a distribution chamber communicating a first end of the channels with a respective one of the two connection ports of the module with the outside.

Thus, the channels converge towards the distribution chamber. This reduces the size of the chamber of distribution and thereby reduce the mechanical problems that it is likely to pose. At the same time, the aforementioned convergence contributes to the fairness of flow distribution. The distribution chamber is surrounded by channel openings over a large part of its circumference, which contributes to its good forming and good stability of its shape.

It is particularly advantageous that the converging regions of the channels follow a circle segment pattern, all the circle segments preferably having substantially the same center.

In general, one of the very significant innovative aspects of the present invention, which is found both in the preferred embodiment of the U-turn and in the preferred embodiment of the end zone of the present invention. channels, is the production of curvilinear welding beads, preferably circular, for producing channels themselves curvilinear and preferably circular, by hydroforming, having a substantially retained section.

One of the difficulties of hydroforming is that, during swelling, some areas are stiffeners preventing good deformation of other areas. Surprisingly, the circular channels have not shown such a phenomenon disadvantageously. A particular advantage has been noted: the channels that must make a very small turn swell less well than the channels that make a larger turn, which automatically compensates for the fact that the fluid traveling through the larger radius channels has longer trip to make. The effect is the opposite for the channels reserved for the second exchange fluid circulating between the modules, but this is not a problem if the relative arrangement of the modules allows the second fluid to pass from one channel to the other.

• un empilement de modules d'échange thermique selon le premier aspect, installés dans une gaine de façon que les extrémités des configurations en U soient dirigées d'un même côté de l'empilement, ces modules définissant entre eux à l'intérieur de la gaine des passages pour un deuxième fluide d'échange;
• des premiers moyens de raccordement pour raccorder les orifices de raccordement des modules avec un premier circuit extérieur et;
• des seconds moyens de raccordement pour raccorder lesdits passages avec un second circuit extérieur.

According to a second aspect of the invention, the heat exchanger is characterized in that it comprises:

• a stack of heat exchange modules according to the first aspect, installed in a sheath so that the ends of the U configurations are directed from one and the same side of the stack, these modules defining between them inside the sheath passages for a second exchange fluid;
• first connection means for connecting the connection ports of the modules with a first external circuit and;
• second connecting means for connecting said passages with a second external circuit.

Other features and advantages of the invention will emerge from the description below, relating to non-limiting examples.

• la figure 1 est une vue en perspective d'un module selon l'invention, avec arrachement central, à un stade intermédiaire de fabrication;
• la figure 2 est une demi-vue en plan d'une partie du module de la figure 1;
• la figure 3 est une vue en coupe suivant III-III de la figure 2, pendant l'hydroformage;
• la figure 4 est une vue en coupe suivant IV-IV de la figure 3;
• la figure 5 est une vue partielle éclatée illustrant l'assemblage des modules pour former le faisceau;
• la figure 6 est une vue partielle après ledit assemblage;
• la figure 7 est une vue de détail en perspective, avec arrachements, illustrant le calage entre les modules dans le faisceau;
• la figure 8 est une vue en perspective de plusieurs modules empilés dans le faisceau, avec arrachements;
• les figures 9 et 10 sont des vues en coupe suivant IX-IX et respectivement III-III de la figure 2, après empilement des modules;
• la figure 11 est une vue en coupe longitudinale de l'échangeur dans une position de service;
• la figure 12 est une vue en perspective éclatée, avec arrachements, montrant l'échangeur, en position inversée pour plus de clarté;
• la figure 13 est une vue en perspective partielle illustrant la suspension du faisceau;
• la figure 14 est une vue partielle en perspective, avec arrachements, illustrant des moyens de positionnement des modules transversalement à leur propre plan;
• la figure 15 est une vue en coupe suivant XV-XV de la figure 16;
• la figure 16 est une vue analogue à la figure 2 mais relative à un second mode de réalisation;
• la figure 17 est une vue analogue à la figure 3 mais prise suivant XVII-XVII de la figure 16;
• la figure 18 est une vue en coupe suivant XVIII-XVIII de la figure 17,
• la figure 19 est une vue en coupe suivant XVII-XVII de la figure 16 après empilement des modules;
• la figure 20 est une vue partielle en perspective montrant un troisième mode de réalisation d'un module au voisinage de l'orifice de raccordement;
• la figure 21 est une vue en perspective partielle des moyens de raccordement d'un faisceau équipé de modules selon la figure 20;
• la figure 22 est un schéma général de l'échangeur équipé d'un tel faisceau;
• la figure 23 est une vue en perspective illustrant une variante pour les barrettes de la figure 21;
• la figure 24 est une vue générale pour une variante d'implantation de l'échangeur; et
• la figure 25 est une vue en perspective illustrant une variante de la figure 21.

In the accompanying drawings:

• Figure 1 is a perspective view of a module according to the invention, with central tear, at an intermediate stage of manufacture;
• Figure 2 is a half-plan view of a portion of the module of Figure 1;
• Figure 3 is a sectional view III-III of Figure 2, during hydroforming;
• Figure 4 is a sectional view along IV-IV of Figure 3;
• Figure 5 is an exploded partial view illustrating the assembly of the modules to form the beam;
• Figure 6 is a partial view after said assembly;
• Figure 7 is a detail view in perspective, with detachments, illustrating the wedging between the modules in the beam;
• Figure 8 is a perspective view of several modules stacked in the beam, with tearing;
• Figures 9 and 10 are sectional views along IX-IX and III-III respectively of Figure 2, after stacking modules;
• Figure 11 is a longitudinal sectional view of the exchanger in a service position;
• Figure 12 is an exploded perspective view, broken away, showing the exchanger, in the inverted position for clarity;
• Figure 13 is a partial perspective view illustrating the suspension of the beam;
• Figure 14 is a partial perspective view, with cutouts, illustrating means for positioning the modules transversely to their own plane;
• Figure 15 is a sectional view along XV-XV of Figure 16;
• Figure 16 is a view similar to Figure 2 but relating to a second embodiment;
• Figure 17 is a view similar to Figure 3 but taken along XVII-XVII of Figure 16;
• Figure 18 is a sectional view along XVIII-XVIII of Figure 17,
• Figure 19 is a sectional view along XVII-XVII of Figure 16 after stacking modules;
• Figure 20 is a partial perspective view showing a third embodiment of a module in the vicinity of the connection port;
• FIG. 21 is a partial perspective view of the connection means of a beam equipped with modules according to FIG. 20;
• Figure 22 is a general diagram of the exchanger equipped with such a beam;
• Fig. 23 is a perspective view illustrating an alternative for the bars of Fig. 21;
• Figure 24 is a general view for an alternative embodiment of the exchanger; and
• FIG. 25 is a perspective view illustrating a variant of FIG.

In the example shown in FIGS. 1 to 14, a heat exchange module 1 (FIG. 1) is obtained by laser welding of two initially flat metal sheets 2, cut in an identical contour. The outline of the sheets 2 has a very generally rectangular shape whose length corresponds to the vertical direction of FIG. 1. At a rear end 9 of this length, each angle of the contour of the sheets 2 has a chamfer 3. At the other end 19 of its length, or "module head", the outline forms two domes 4 of generally semicircular shape arranged side by side, each extended by a projection 6 in the general shape of trapezium, whose apex 7 corresponds to the small base of the trapezium.

The width of the sheets 2 can range, for example, from 100 to 1600 mm. The length of the sheets is limited only by the size of the means available to limit the expansion in thickness during the hydroforming operation which will be described later. In practice, sheets of 10 meters and more are possible. However, thanks to the progress in compactness made possible by the invention as has been explained above, sheets of a length of for example 8 meters already allow considerable exchange performance, in terms of heat transfer power.

The thickness of the sheets can range from 0.2 to 1.5 mm. It is therefore very weak for economic as well as thermal reasons.

The two sheets 2 are welded against each other so that their contour is in coincidence. The welding is done by laser. This known technique makes it possible to weld the sheets to one another at a distance from their edges by means of a beam passing through the sheets, causing their localized melting in the mass and the reciprocal interpenetration of the metal constituting the two sheets.

The two sheets are thus joined to each other by a peripheral weld bead 8 which generally follows the outer contour of the two sheets at a distance of a few centimeters below said contour. The peripheral bead 8 thus forms a continuous outer U comprising two longitudinal sections 13a which are parallel to each other, each along a respective one of the longitudinal edges 14 of the outline of the sheets, and a semicircular bead 11a which runs along the contour of the rear end 9 of the module and joins the two longitudinal sections 13a.

Between the two domes 4, the outline of the sheets forms a recess with a bottom 16 located for example a little below a line 17 parallel to the width of the sheets 2 and passing through the geometric centers 18 of the domes 4. In this zone, the peripheral bead 8 moves away locally from the outer contour of the sheets and more particularly forms a continuous inner U comprising two longitudinal inner cords 13g parallel to each other and to the outer longitudinal cords 13a, and an inner semicircular cord 11g. The cord 11g has the same center 12 as the outer semi-circular cord 11a and connects the two inner longitudinal beads 13g. At the head 19 of the module, each outer longitudinal cord 13a and the inner longitudinal cord 13g closest are joined to each other by a bead-shaped cord comprising two circular segments belonging to the same circle centered on the center 18, one 21a extending the outer longitudinal cord 13a, the other 21g extending the inner longitudinal cord 13g. The two segments 21a and 21g of each dome 4 are connected to each other by a connecting cord 22 approximately along the contour of the boss 6. However, one of the connecting cords 22 is interrupted in its middle in one location where a tubular tip 23 is inserted between the two sheets 2 to allow the injection of a hydroforming fluid from the outside of the module into the space between the two sheets and surrounded by the peripheral bead 8. A apart from the passage formed by the endpiece 23, the peripheral bead 8 sealingly closes the space it surrounds between the two sheets 2.

Between each outer longitudinal bead 13a and the inner longitudinal bead 13a there is a series of parallel and equidistant longitudinal beads each extending between the diametrical line 17 and the diametrical line 24 passing through the center 12 perpendicular to the cords 13a and 13b. 13g. In the example shown, the cords longitudinal lengths are in an odd number on each side of the central axis A. A central longitudinal bead 13d extends along a secondary longitudinal axis B located equidistant between the outer longitudinal cord 13a and the inner longitudinal cord 13g nearest.

Intermediate outer longitudinal beads 13b are located between the bead 13a and the B axis. Intermediate inner longitudinal beads 13f are located between the B axis and the inner longitudinal bead 13g. 13c and 13e denote the two intermediate longitudinal beads adjacent to the central cord 13d, and located on the side of the outer bead 13a and the side of the inner bead 13g respectively.

At the rear end 9 of the module, each intermediate longitudinal bead 13b, 13c, 13e, 13f or central 13d is connected to the symmetrical longitudinal bead with respect to the central axis A of the module by a semicircular bead 11b, 11c, 11e , 11f or respectively 11d concentric with the inner semi-circular cords 11a and inner 11g already described.

It has therefore been formed between the outer U 13a, 11a, 13a and the inner U 13g, 11g, 13g already described, several continuous U-shaped cords defining between them a group of channels 25 having a U-shaped configuration. width - or "no succession of channels" - which is the same for all channels and is constant along all channels.

At the head 19 of the module, the intermediate longitudinal weld seams 13b and 13f are extended by cords in the form of circular segments 21b and 21f respectively which are centered at 18 and which terminate along a lateral edge of a distribution chamber 26 which is further delimited by the weld bead 22 already described. Thus, the channels 25 defined between the weld beads have at each end of the U a region 21ac or 21cg converging to a distribution chamber 26 with which they communicate. 21ac regions, between the outer bead 21a and the intermediate bead 21c, curved towards the central axis B of the U branch and to the axis A of the module. The regions 21cg, between the cords 21c and 21g, curve towards the axis B while coming from the other side thereof, and away from the axis A. The regions 21ac open perpendicularly through one side of the distribution chamber 26 and the regions 21cg open perpendicularly across another side of the distribution chamber 26. The channels 25 even retain in the convergent region 21ac or 21cg a width - or "no succession of channels" - unchanged from the rest of the channels. Each convergent region 21ac follows a path substantially located in the curvilinear extension of the convergent region 21cg of another channel 25 located symmetrically with respect to the B axis in the group of channels. Similarly, each curvilinear cord 21b is in the curvilinear extension of a cord 21f, the distribution chamber 26 forming an interruption between these two cords. On the other hand, the two longitudinal weld seams 13c and 13e located immediately on either side of the central cord 13d are connected to each other in a continuous manner by a semicircular cord 21c centered at 18, and the cord central 13d is terminated at 18 by a point or "solder button" for increasing the mechanical strength of the end of the cord. Still for the sake of mechanical strength of welding, each cord in the form of a circular segment 21b or 21f ends with a "button" of welding 27 preceded by an interruption 28, see also FIG. 2. Such a button may in practice be constituted by a circular or ovoid cord of small diameter.

For hydroforming, the two still flat plates 2 are placed between two generally plane matrixes 31 and 32 (FIG. 3) with a free distance E between them corresponding to the desired external thickness for the modules in the region of the channels. In the region intended to correspond to the distribution chamber 26 of the module, the inner face of the matrices 31 and 32 has a boss 29 intended to reduce the free distance between them to a value "e" which is lower for the distribution chamber 26 than for the channel region 25.

The hydroforming operation consists in injecting a liquid such as pressurized water between the two sheets 2 through the nozzle 23. The water trapped between the two sheets inside the contour of the peripheral cord 8 produces swelling between the weld seams as well as in the zone of the distribution chamber and this in the limit allowed by the matrices 31 and 32. It thus forms on the one hand the channels 25 described and on the other hand, at each end of the U of the configuration of the group of channels, a distribution chamber 26. The two chambers 26 communicate with each other by means of each channel U defined between two adjacent weld seams, which are thus fluidly in parallel between the distribution chambers 26 Figure 4 shows in cross-section how the channels are formed between the dies 31 and 32 and between the seams 11, 13 or 21.

The sheet regions located outside the peripheral bead 8 and between the two longitudinal cords 13c and 13e and between the two semicircular cords 11c and 11e corresponding are not subjected to pressure and thus undergo no swelling. They remain flat and adjacent to each other. These external zones 33a 33d intermediate and 33g internal stiffeners that have proved beneficial for the good flatness of the module after hydroforming.

To pass from the blank shown in Figure 1, resulting from the hydroforming to a module itself ready for assembly to form an exchange beam, is cut with a saw or water jet the top of each boss 6 as shown in Figure 2 along a line 34 so as to open each distribution chamber 26 and remove the tip 23. The module thus has two connecting ports 38 (Figures 5 and 6) both located at the head 19 of the module being offset relative to each other laterally, that is to say parallel to the width of the module. Each distribution chamber 26 has a generally isosceles triangular shape, symmetrical with respect to the axis B. The connection orifice 38 is formed through the base of this triangle. Both sides of the triangle are each defined by the alignment of the ends of the convergent regions 21ac or 2cg respectively of the channels 25 and together form on the axis B an angle C less than 60 °, preferably equal to about 45 °, opposite the orifice of connection 38. Solder cords 22a, 22g (FIG. 5), which remain from the initial cord 22, each extend around a portion of the periphery of the distribution chamber 26 between the respective curvilinear weld seams. 21a, 21g and a corresponding end of the connecting port 38, which is elongated. The weld bead 21c sealingly connecting the two longitudinal beads 13c and 13e closes the distribution chamber 26 at its apex forming the angle C. Within the contour of each chamber 26, the two sheets 2 are free of mutual connection, and in particular soldered connection.

Moreover, as illustrated in phantom in FIG. 1, it is practiced by cutting in the inner flat zone 33g situated inside the interior U 11g, 13g, a notch 36 along the main axis A from the bottom 16 of the recess between the two domes 4 and about to the center 12 of the U-channel bend at the rear end 9 of the module.

In addition, it is practiced in the longitudinal edges 14 adjacent the bevels 3 two notches of generally rectangular shape 37 in the sheets 2.

Figures 5 and 6 illustrate the assembly of the modules to form a beam. At each end of the U of the channel configuration of each module, the connection orifice 38 formed by the cutout 34 of the boss 6 is fitted into correspondingly shaped openings 39 provided in an end plate 41 common to all the modules. beam to achieve. Measured parallel to the width of the modules, the dimension 42 of the plate 41 is smaller than the width 43 of each arm of U of a module measured between one of the longitudinal edges 14 and the central axis A. The connecting orifices 38 are welded into the openings 39, so as to fix the modules in a relative stacking position. The geometry of the stack is also defined by means bracing member may comprise wedges 44 (FIG. 7) welded against the outer and inner plane zones 33a, 33g of the modules, or against the intermediate flat zone 33d. These wedges prevent the modules from moving relative to each other, in particular transversely to their own plane. Triangular wedges 46 are also used which are interposed between the adjacent distribution chambers 26 to prevent, in use, the swelling of the distribution chambers 26 under the effect of the pressure prevailing in service inside the modules, which is in most applications superior to that of the exchange fluid that will flow between the modules.

FIG. 8 illustrates that, for the example represented, two types of modules 101, 102 are used which alternate in the stack and which differ by a shift of the channels, the offset being a half-step of succession of the channels. Thus, in particular the inner longitudinal cords 13g of the modules 101 are closer - by a half-pitch of the channels - of the axis A than the cords 13g of the modules 102, and the radius of the semi-circular cords 11g of the modules 101 is smaller - by a half-pitch of succession of the channels - than the cords 11g of the modules 102. Thus, more generally, the channels 25 generally have a staggered arrangement which is further illustrated in FIG. 9, the crests d ripple 47 of the outer face of a module being opposite ripple recesses corresponding to the weld seams 11, 13 or 21 of an adjacent module. With this configuration, the path 48 provided for the second exchange fluid between each pair of adjacent modules has the form of a corrugated continuous gap. The inlet or the outlet of the second fluid between the modules is at each end of the U, respectively, between the zones 21ac and 21cg of the channels 25, on either side of the triangular wedges 46, and without restriction of section thanks to the offset by half a step. FIG. 10 shows along the section line III-III of FIG. 2 the stack of two modules in the zone of the distribution chambers 26 and the beginning of certain channels 25.

Once the stack of modules constituted, it is inserted into a sheath 49 (Figures 11 and 12), the longitudinal direction corresponds to that of the modules 1. The peripheral wall 52 of the sheath 49 has a correpondant rectangular inner profile as close as possible to the transverse external profile of the stack of modules 1 taking into account the manufacturing tolerances. The sheath 49 further comprises, according to one of the medians of its rectangular profile, a median partition 53 intended to fit as closely as possible into the notch 36 of the modules 1.

At the rear end of the sheath 49, which corresponds to the rear end 9 of the modules, the sheath 49 is closed by a housing 54 having bevels 56 intended to be substantially in contact with the bevels 3 of the modules. In general, to place the beam in the sheath, the beam is passed through the back of the sheath until the bottom of the notch 36 of the modules abuts against the rear edge of the central partition 53 of the sheath, then the sheath 49 is closed thanks to the casing 54.

In use (Figure 11) the rear end 9 of the modules and the casing 54 of the sheath are placed in the up position.

At the top of the peripheral wall 52 are fixed by welding two opposite bars 57 (see also Figure 13) which protrude inwardly of the sheath and are engaged in the notches 37 of the modules. The beam is thus suspended by pressing the shoulders 58 forming the upper edge of the notches 37 against the upper face of the bars 57. The bars 57 also protrude outside the sheath 49 to rest on consoles 59 fixed against the inner face of a cylindrical enclosure 61 enclosing the beam, the sheath 49 and the beam connection means which will be described.

The rear end 9 of the modules being placed in the high position, their heads 19 and with them the connection means still to be described are grouped in the lower position in the lower end of the enclosure 61. For the first exchange fluid, intended to circulate inside the modules, the connection means comprise two junction boxes 62 (FIG. 12) of generally semicylindrical shape. Each box 62 is welded in a sealed manner by its open rectangular periphery, with the periphery of a respective one of the plates 41 to communicate all the connecting orifices 38 located on the same side of the axis A with a connecting pipe 63 for the entry of the first fluid, and to communicate all the orifices 38 located on the other side of the axis A with a connecting duct 64 for the output of the first fluid. Each duct 63, 64 opens into the respective junction box 62 and reaches the outside through a sealed passage 66 of the enclosure 61 (FIG. 11) to form part of a first external circuit, for the first exchange fluid .

Each connection box 62 has a generally semi-cylindrical shape with respect to which the corresponding plate 41 extends substantially along an axial plane.

An outer junction box 67, larger than the boxes 62, is mounted to enclose one of the boxes 62. The box 67 is attached to the upper edge of one of the two longitudinal compartments defined in the sheath 49 by the middle partition 53 and one of the half of the rectangular profile of the peripheral wall 52. The box 67 communicates this compartment sealingly with a connecting conduit 68 which opens into the box 67 for the arrival of the second fluid in this compartment the sheath passing from both sides of the junction box 62 which is surrounded by the box 67. The duct 68 extends to the outside of the enclosure 61 through a sealed passage 69 and thus part of a second external circuit, for the second exchange fluid. The other compartment defined in the sheath 49 by the partition 53 is freely open in the chamber 61 which serves as a return collector for the second fluid. The enclosure 61 is connected for this purpose with the outside by a connection 71 also forming part of the second external circuit. Each connecting duct 63, 64, 68 is equipped with a respective expansion compensator 72 to absorb the variations dimensions between the head 19 of the beam and the corresponding watertight passage 66 or 69 of the enclosure. The connecting duct 64 passes sealingly through the connection box 67 with the interposition of an expansion compensator 73 between the connection box 67 and a sealing collar 74 fixed around the duct 64. All the expansion compensators are mounted to compensate the dimensional variations in the longitudinal direction of the modules. The two ends of the U-shaped configuration of the modules are made mechanically independent of one another for longitudinal displacements because in use, the hot end where the fluid intended to transfer calories and from which flows the fluid having received calories must be able to expand much more than the cold end.

In operation, the first exchange fluid enters one of the distribution chambers 26 of each module, through one of the junction boxes 62, traverses the U-shaped channels arranged in parallel fluidically, collects in the other chamber 26 and leaves the beam through the other junction box 62. The connecting chambers 26 have a triangular shape so that their cross section decreases from the connection port 38 to the most central channels. This has the effect that the fluid is distributed approximately evenly between the channels 25 and that the fluid flow velocity is almost everywhere the same along one module, from one connection port to the other . The second exchange fluid enters one of the compartments of the sheath via the junction box 67 on either side of the corresponding junction box 62 and is distributed throughout the gap between the neighboring modules, thanks to the continuity of said gap 48 (FIGS. 8 and 9). The second exchange fluid must bypass the rear end of the partition 53, and therefore must travel, against the current relative to the first fluid, the entire developed length of the channels of the modules. The wedges 44 (FIG. 7) prevent the second exchange fluid from choosing the thermally inefficient path preferentially. extending between the flat areas 33a, 33d, 33g of the neighboring modules. This flow braking effect along the flat zones can be increased by different baffle elements such as, for example, sinusoidal springs 76 interposed with a certain stress between the plane zones 33a, 33d and 33g of the modules (FIG. 7). or else combs 77 (FIG. 14) fixed against the inner faces of the sheath adjacent to the lateral edges of the modules. Such combs advantageously comprise a plate forming a fixing plate, in which are formed by cutting and stamping the punctures 78 forming projections 79. Slots 81 defined between the projections 79 receive and guide the outer planar portions 33a or inner 33g modules. These springs 76 and combs 77 serve at the same time to immobilize the modules with respect to displacements transverse to their own plane.

The example shown in Figures 15 to 19 will be described only for its differences from the previous. In this embodiment, the modules are all identical and, in the stack, the peaks 47 of the undulations of the outer faces of the neighboring modules are in contact or quasi-mutual contact. The path for the second exchange fluid is then also constituted by channels almost completely separated from each other. So that the second exchange fluid can feed these channels 48, it is ensured during hydroforming that a region 82 (Figure 16) of the channels, adjacent to the distribution chamber 26 on either side of the ci, has a reduced thickness, for example equal to the thickness e of the distribution chamber 26. Suffice it that the boss 29 of the matrices 31 and 32 has a corresponding greater extent than in the previous embodiment. In this region, the flattened channels 83 shown in FIG. 18 are obtained. Thus, in the region 82, the passages 48 are interconnected by interconnections 84 (FIG. 19) and form with them a distribution chamber for the second exchange fluid.

In the example shown in Figures 20 to 22, which will be described only for its differences with that of Figures 1 to 14, the modules without distribution chamber are made simply by sectioning the blank 1 of Figure 1 along the line 17. All the region of the domes 4 was only used for hydroforming before being removed. It is therefore the open ends of the longitudinal channels that form the connection port of the module at each end of the U-shaped configuration.

The modules are assembled by welding together, between their connecting ports, shaped strips 86 which together constitute a base on which the connection box 62 will be welded. This latter is of larger size than in FIG. 12 and completely closes the compartment. corresponding to the sheath 49. The junction boxes 87 for the second exchange fluid are fixed so as to close a rectangular notch 88 formed at the top of the sheath 49 in each of the two walls of the sheath parallel to the partition 53. ends 89 of the bars 86 form with the edges of the modules interposed between them a continuous surface against which a corresponding edge 91 of the connection box 87 may be sealed welded. In FIG. 22, two connection boxes 87 are shown, but one of them may be omitted if the enclosure 61 is used as a collector as has been described with reference to FIG. 12.

Figure 23 illustrates an alternative for the bars 86 with a welding lip 93 along the edge of each adjacent sheet 2. In a manner not shown, the bars 86 must also have at each end a transverse lip for sealing the edge of the connection box 62.

FIG. 24 illustrates a so-called cross-current embodiment wherein the bundle of modules is mounted in a sheath 95 which is open over the entire surface adjacent to the outer longitudinal edges 14 of the modules on each side of the bundle. In this case there is no partition separating the two branches of the U, and it is therefore not necessary to form the notch 36 between the two branches of the U However, thanks to the invention, even in this version, certain advantages of the countercurrent are obtained if the flow direction 94 of the second fluid is such that it passes firstly between the branches of U situated downstream relative to the flow direction of the first fluid, as shown. This embodiment requires that the gap 48 reserved between the modules for the path of the second fluid be continuous, for example as shown in FIG. 9.

The embodiment of FIG. 25 will be described only for its differences with respect to that of FIGS. 20 to 22. In a certain region 97 adjacent to their open ends forming a connection orifice, the modules have been given during their hydroforming a reduced thickness so as to form in this area a distribution chamber 96 for the second exchange fluid. The modules are all identical and the ripples of the neighboring modules are in peak-to-peak contact except in the region of reduced thickness 97. The profile of the strips 86 is correspondingly adapted.

Of course, the invention is not limited to the examples described and shown.

The exchanger could be designed to exchange heat between more than two fluids. The U turn zone could be configured differently. It is not necessary to have a flat area in the middle region of the channel group.

The embodiment of FIGS. 1 to 14 more particularly relates to the case where the first exchange fluid is essentially liquid while the second exchange fluid is at least partially gaseous, thus requiring larger passage sections, but this is not the case. is not a necessity.

The invention is applicable to exchangers where the two exchange fluids circulate in the same direction along their respective paths.

In the embodiment of FIGS. 20 to 23 and 25, the head structure of the modules before the cut intended to make appearing the two connection ports of each module, is only used for the implementation of the hydroforming. It has no hydrodynamic function, and its requirements for resistance to temperature and pressure may be lower. It can be simplified accordingly, in particular to facilitate its manufacture and save the sheet.

We could give the channels of the same module, different widths from one channel to another.

In the embodiments shown, the channels 25 open through the rectilinear sides of the distribution chambers 26. But these sides can also be curvilinear, concave or convex, for example but not limited to a segment of a circle.

Claims (43)

1. Heat exchange module intended to be a part of a stack of such modules and comprising two metal sheets (2) joined along lines (11, 13, 21) defining between them a group of channels (25) disposed side by side substantially in a common plane, intended to be passed through by an exchange fluid and, from the fluidic point of view, being in parallel with each other from one to the other of two connection orifices (38) of the module, the group of channels having a generally U-shape configuration which presents a bend between two longitudinal legs and which connects together the said connection orifices (38), characterized in that said lines fix the metal sheets (2) together by welding and the connection orifices (38) are disposed to receive connection means (62) that are laterally separated from each other.
2. Heat exchange module according to Claim 1, characterized in that the weld seams delimit for each channel two opposite lateral edges, each of said edge forming, in a plane view, a path without angular point.
3. Heat exchange module according to Claim 1 or 2, characterized in that the two connection orifices (38) are disposed side by side at a same end (19) of the module (1).
4. Heat exchange module according to one of Claims 1 to 3, characterized in that the weld lines are seams (11, 13, 21) that extend along a continuous U-shape path.
5. Heat exchange module according to Claim 4, characterized in that in the bend of the U-shape the weld seams form concentric arcs of circle (11 to 11g).
6. Heat exchange module according to one of Claims 1 to 5, characterized in that the two legs of the U-shape configuration of the group of channels are separated by a zone (33g) without channels.
7. Heat exchange module according to Claim 6, characterized in that the zone without channels (33g) is at least partly constituted by welded flat parts of the metal sheets.
8. Heat exchange module according to Claim 6 or 7, characterized in that the zone without channels (33g) comprises a slot (36) formed in the two metal sheets (2) between the two legs of the U-shape configuration of the channels, starting from one edge (16) of each metal sheet (2) located between the two ends of the U-shape.
9. Heat exchange module according to one of Claims 1 to 8, characterized in that it comprises between certain channels (25), and/or along the outer periphery of the U-shape configuration, a stiffening zone (33a, 33d) constituted by mutually adjacent flat regions of the two metal sheets.
10. Heat exchange module according to one of Claims 1 to 9, characterized in that in each leg of the U-shape configuration the channels are straight and parallel up to their ends which together constitute, at the end of each leg, a respective one of the connection orifices (Figures 20 to 23 and 25).
11. Heat exchange module according to one of Claims 1 to 9, comprising at least one distribution chamber (26) connecting a first one of the two ends of the channels with a respective one of the two connection orifices (38) of the module (1).
12. Heat exchange module according to Claim 11, characterized in that starting from a longitudinal region the channels have at their first respective end a convergent region (21ac, 21cg) which incurves towards the distribution chamber (26).
13. Heat exchange module according to Claim 12, characterized in that the distribution chamber (26) is substantially symmetrical with respect to a longitudinal axis (B) of the group of channels, the convergent regions of the channels incurving in a same respective direction on each side of this axis.
14. Heat exchange module according to Claim 12 or 13, characterized in that the convergent regions follow a path shaped like a segment of circle, preferably having the same centre (18):
15. Heat exchange module according to one of Claims 12 to 14, characterized in that the channel succession pitch remains substantially constant along the convergent regions, and substantially equal to the succession pitch of the longitudinal regions of the channels (25).
16. Heat exchange module according to one of Claims 11 to 15, characterized in that the convergent region (21ac, 21cg) of each channel (25) follows a path substantially situated in the curved extension of the convergent region of a channel disposed symmetrically in the group of channels.
17. Heat exchange module according to one of Claims 11 to 15, characterized in that, at the ends of the channels, continuous weld seams separating the adjacent channels are followed by a spot weld (27) a small distance (28) beyond each seam (21).
18. Heat exchange module according to one of Claims 11 to 17, characterized in that inside its contour the distribution chamber (26) has no welded connection between the two metal sheets.
19. Heat exchange module according to one of Claims 11 to 18, characterized in that the distribution chamber (26) has a generally triangular shape with, on the longitudinal axis (B) of the group of channels, an apex whose angle (C) is preferably equal to 45°, opposite the connection orifice (38) passing through the base of the chamber (26).
20. Heat exchange module according to one of Claims 11 to 19, characterized in that the convergent regions of the channels emerge through two sides of the distribution chamber (26) which converge towards each other in the direction going from the connection orifice (38) towards an end of the chamber opposite the connection orifice (38).
21. Heat exchange module according to one of Claims 11 to 20, characterized in that the convergent regions of the channels emerge approximately perpendicularly through two sides of the distribution chamber (26).
22. Heat exchange module according to one of Claims 11 to 21, characterized in that it comprises two weld seams (22a, 22g) each extending around a part of the periphery of the distribution chamber (26) between a respective extreme weld seam (21a, 21g) of the group of channels and a respective end of the connection orifice (38).
23. Heat exchange module according to one of Claims 11 to 22, characterized in that at its end opposite to the connection orifice (38), the distribution chamber (26) is closed by a weld seam (21c) connecting to each other two weld seams (13c, 13e) bordering a gap between two central channels of the group of channels.
24. Heat exchange module according to one of Claims 11 to 23, characterized in that in the direction of the thickness of the module, the distribution chamber has a dimension (e) smaller than that (E) of the channels.
25. Heat exchange module according to one of Claims 11 to 24, characterized in that there is a connection orifice (38), a distribution chamber (26) and a convergent region (21ac, 21cg) of the channels (25) at each one of the two ends of the group of channels.
26. Heat exchange module according to one of Claims 1 to 25, characterized in that in the direction of the thickness of the module the channels have a reduced dimension in a zone (82, 97) adjacent to the ends of the channels.
27. Heat exchanger, characterized in that it comprises:

    - a stack of heat exchange modules (1) according to one of Claims 1 to 26, installed in a cover (49) in such a way that the ends of the U-shape configuration are directed on a same side of the stack, these modules defining, between them and inside the cover, passages (48) for a second exchange fluid;

    - first connection means (62, 63, 64) for connecting the connection orifices (38) of the modules with a first external circuit;

    - second connection means (67, 68, 71) for connecting the said passages (48) with a second external circuit.
28. Heat exchanger according to Claim 27, characterized in that the peaks (47) of the undulations of the outer adjacent faces of neighbouring modules are mutually facing each other.
29. Heat exchanger according to Claim 28, characterized in that for each pair of adjacent outer faces of neighbouring modules, the undulation peaks (47) of each face of the pair are substantially facing undulation troughs of the other face of the pair.
30. Heat exchanger according to Claim 29, characterized in that it comprises two types of module (101, 102) which differ by an offset of a half-pitch of the longitudinal regions of the channels with respect to the central axis (A) of the U-shape, and in that the modules of one type alternate with the modules of the other type in the stack of modules.
31. Heat exchanger according to one of Claims 27 to 30, characterized in that the cover (49) contains means (44, 76, 77) of positioning the modules with respect to displacements perpendicular to the plane of the modules.
32. Heat exchanger according to one of Claims 27 to 31, characterized in that the first connection means comprise a connecting box (62) comprising:

    - a base (41) through which the orifices (38) of the modules emerge in a fluid-tight manner;

    - a body to which is connected a pipe (63, 64) for connection with the first external circuit.
33. Heat exchanger according to Claim 32, characterized in that the second connection means comprise a second connecting box (67) which:

    - is connected to the cover (49);

    - encloses the box (62) of the first connection means,

    - is passed through in a fluid-tight manner by the connecting pipe (64) of the first connection means

    - and to which a second connecting pipe (68) is connected in a fluid-tight manner.
34. Heat exchanger according to one of Claims 27 to 32, characterized in that the second connection means connect the second external circuit with distribution zones (84) extending at least partly between zones of reduced thickness (82, 97) of the channels.
35. Heat exchanger according to one of Claims 27 to 34, characterized in that the first and second connection means are gathered at one end of the exchanger corresponding to the two ends of the U-shape.
36. Heat exchanger according to one of Claims 27 to 34, characterized in that the first connection means (62) are disposed at a same end of the exchanger, whilst being mutually separated from one end to the other of the U-shape in such a way as to ensure thermal decoupling.
37. Heat exchanger according to Claim 35 or 36, characterized in that the said end is a lower end.
38. Heat exchanger according to one of Claims 27 to 37, characterized by a recess (36) separating the two longitudinal legs of the U-shape configuration of the channels of the modules.
39. Heat exchanger according to Claim 38, characterized in that the cover (49) comprises a partition (53) extending across the recesses (36) of the modules.
40. Heat exchanger according to Claim 38 or 39, characterized in that the first connection means are mounted in a mechanically decoupled manner in order to allow a different expansion of the two legs of the U-shape in the direction of the length of the said legs.
41. Heat exchanger according to one of Claims 27 to 40, characterized in that at its end opposite to the connection means the cover is closed by an end-cover (56) covering the bend of the U-shape configuration of the channels of the modules.
42. Heat exchanger according to one of Claims 27 to 41, characterized in that in the cover the modules are separated by spacing means (44, 76, 79) along the outer periphery and/or the inner periphery of the U-shape configuration of the group of channels of each module.
43. Heat exchanger according to one of Claims 27 to 42, equipped with modules according to one of Claims 11 to 26, comprising support and spacing means (46) between the distribution chambers (26) of the successive modules.

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