EP0569293A1 - Heat exchanger and method of manufacturing same - Google Patents

Abstract

This heat exchanger is composed of packets (3) of unit fins (2), through which a tube (1) is passed, while leaving free regions in this tube (1) to allow it to be subsequently bent in order to place the various packets (3) in juxtaposed positions, with vertical stacks and/or horizontal piles, the assemblies thus obtained being supplemented by corresponding flanges (4). <IMAGE>

Description

The radiant fin heat exchangers that are being manufactured are formed using welded fins, forks and elbows.

That is to say that a set of fins arranged parallel one behind the other is used, each of which has a series of orifices in the direction along the longitudinal axis of the fin so as to define thus, in the direction perpendicular to the fins, alignments between the orifices of the different fins. The corresponding straight sections of the tube through which the refrigerant must circulate are passed through these orifices.

These straight sections of the tube are joined together, by respective elbows, welded at their ends, thereby defining the corresponding circuit for the refrigerant.

Faced with this classic embodiment, the invention proposes a new heat exchanger which has the particularity of being constituted by bundles of elementary or unitary fins. That is, each fin has only one through hole for the coolant tube.

A second particularity of this heat exchanger lies in the fact that the tube inside which the refrigerant will circulate is a unique whole and that it is not formed of segments joined by elbows.

The manufacturing process for this new heat exchanger takes place by first forming bundles of individual fins.

These packages are placed so that the straightened tube passes through the single orifice of each unitary fin. This tube is then expanded to establish contact with the radiant fins.

The different packages of unitary fins are arranged leaving free the areas of the tube which must then be bent so that once produced this bending, it is sufficient to place respective lateral flanges at the ends so that the heat exchanger is formed.

• Elimination des soudures ;
• Propreté totale de l'intérieur. C'est-à-dire que le tube étant unique, sa cavité intérieure offre une parfaite continuité dans sa surface, qui évite les risques de formation de dépôts indésirables et que ceci favorise aussi son nettoyage ;
• Etanchéité garantie, puisque le fait que l'agent réfrigérant circule dans un tube unique exempt de soudures, élimine les risques d'éventuels défauts dans les soudures, qui donnent lieu à des fuites ;
• Elimination du dégraissage avec des produits chlorés qu'exigent les solutions traditionnelles, produits qui sont incompatibles avec les nouveaux fréons utilisés comme agents réfrigérants ;
• Modularité de l'échangeur de chaleur, aussi bien pour le fabricant de l'échangeur que pour le distributeur ou également pour l'utilisateur final, qui permet de réduire sensiblement les stocks ;
• Possibilité d'utiliser diverses matières, contrairement à l'usage pratiquement exclusif du cuivre qui est adopté actuellement.

Compared to traditional solutions, the proposed solution therefore offers the following advantages:

• Elimination of welds;
• Total cleanliness of the interior. That is to say that the tube being unique, its internal cavity offers perfect continuity in its surface, which avoids the risks of formation of undesirable deposits and that this also promotes its cleaning;
• Guaranteed tightness, since the fact that the refrigerant circulates in a single tube free of welds, eliminates the risk of possible defects in the welds, which give rise to leaks;
• Elimination of degreasing with chlorine products required by traditional solutions, products which are incompatible with the new freons used as refrigerants;
• Modularity of the heat exchanger, as well for the manufacturer of the exchanger as for the distributor or also for the end user, which allows to significantly reduce stocks;
• Possibility of using various materials, contrary to the practically exclusive use of copper which is currently adopted.

All these improvements give the object of the invention a distinctive character compared to traditional solutions and give it its own identity.

• la figure 1 montre en perspective schématique une partie d'un échangeur de chaleur selon les réalisations traditionnelles ;
• la figure 2 est un schéma dans lequel on représente par phases successives le processus de fabrication et les composants de l'échangeur objet de la présente invention ;
• la figure 3 est une vue en perspective qui montre l'exécution d'un échangeur à serpentin plan avec ses flasques latéraux 4 en phase de montage ;
• la figure 4 correspond à l'échangeur à serpentin plan déjà constitué et désigné par la référence 5 ;
• les figures 5 et 6 montrent deux variantes d'exécution possibles de batteries modulaires dont chacune est formée de trois échangeurs 5 ;
• la figure 7 correspond à une vue en perspective qui montre l'exécution d'un échangeur à serpentin coudé ou hélicoïdal ;
• la figure 8 montre l'échangeur de la figure 7 déjà formé avec ses flasques latéraux 4 en phase de montage.

Other characteristics and advantages of the invention will be better understood on reading the description which will follow of an exemplary embodiment and with reference to the appended drawings in which:

• Figure 1 shows in schematic perspective part of a heat exchanger according to traditional embodiments;
• FIG. 2 is a diagram in which the manufacturing process and the components of the exchanger object of the present invention are represented by successive phases;
• Figure 3 is a perspective view which shows the execution of a flat coil exchanger with its side flanges 4 in the assembly phase;
• Figure 4 corresponds to the planar coil exchanger already formed and designated by reference 5;
• Figures 5 and 6 show two possible alternative embodiments of modular batteries each of which is formed by three exchangers 5;
• FIG. 7 corresponds to a perspective view which shows the execution of an exchanger with a bent or helical coil;
• Figure 8 shows the exchanger of Figure 7 already formed with its side flanges 4 in the assembly phase.

The subject of the invention is a heat exchanger as well as the process for manufacturing this exchanger. According to conventional manufacturing solutions, the heat exchangers are constituted, as shown diagrammatically in FIG. 1, by means of a series of radiant fins a , each of which has a series of orifices arranged along its longitudinal axis of so that, by arranging a series of fins juxtaposed between them according to parallel planes, the orifices of the different fins a are aligned, thus making it possible to thread sections of rectilinear tubes t whose ends are connected by welded elbows c for define in this way the corresponding circuit in which the refrigerant will be circulated.

This classic embodiment implied the need to carry out the assembly by welding between the tubes t and the elbows c , with the particularity that these connections could give rise to leaks and, moreover, in the connection zones between the elbows c and the tubes t , the perfect continuity of the interior surface of the circuit was broken due to the fact that there were connection beads.

Faced with this embodiment, already known, a new solution is now proposed according to which each radiant fin designated by the reference 2 in FIG. 2 is of elementary or unitary nature, with a single orifice 2.1 provided with a self-separating collar 2.2 which delimits the spacing between the different fins 2, when they are placed one behind the other in packages 3, see FIG. 2.

The materials which can be used for the production of the elementary fins 2 can be all those which are interesting by their properties, from the thermodynamic, mechanical and economic point of view, such as aluminum, iron, copper, plastics, etc.

The general shape of each elementary fin 2 will be that required by the construction of the final exchanger, the fin may be round, square, rectangular, polygonal in general, including with mixed contour and the dimensions will be variable, depending on the characteristics of the exchanger.

The different packets 3 of elementary fins 2 are arranged aligned with one another, in the desired number in each case and, through the orifice 2.1, a single tube 1 previously straightened is inserted. This tube 1 constitutes the conduit for the refrigerant and can be made of material such as copper, aluminum, iron, plastics, etc., and its cross section can have a round, elliptical, polygonal configuration, etc.

When the tube 1 is threaded through the package 3, as can be seen in FIG. 2, it is dilated to ensure in this way the establishment contact between the tube 1 and the elementary fins 2.

The packages 3 are thus fixed on the tube 1 and at a mutual spacing such that there remains in the tube 1 free zones which are those which correspond to the zones to be bent.

In a subsequent phase, the tube 1 is bent, which can be done both without filling and with filling which avoids undesirable deformations.

In Figure 3, there is shown a curvature of the tube 1 which defines a flat coil, so that on the element thus configured, there are side flanges 4 provided with an orifice 4.1 for the ends of the tube 1 and grooves 4.2 for the bent areas of the tube 1.

The side flanges 4 can be made of plastic, aluminum, iron, etc. and, when they have been put in place, the heat exchanger is defined as shown in FIG. 1. By combining three exchangers 5, as shown in FIG. 5, a battery is obtained having a parallel geometry , and we have omitted to represent the corresponding couplings of the inlet and outlet manifolds, with biconical fittings, since these are conventional elements.

In Figure 6, there is shown a battery, also composed of three exchangers 5, but with an oblique geometry.

On the other hand, in FIG. 7, another possible variant of an angled or helical coil is presented, which is produced with six packages 3 of fins 2, so that two sets of three packages 3 are obtained which meet then to define an elementary battery with parallel geometry.

In this case, the assembly of the corresponding side flanges 4, as can be seen in FIG. 8.

In some cases, it will be necessary to adopt an alignment between the elementary fins 2, while, in other cases, it will be necessary or advantageous to promote air turbulence.

The different basic batteries can be assembled together using the corresponding fittings.

It should be noted that the configuration of the elementary batteries, both in terms of the appearance of the different curvatures of the tube 1 and in that of the shape, number and distribution of elementary fins 2, can vary without being sorted out for that of the principle of the invention, which basically lies in the realization of the exchanger starting from elementary fins 2 having a single orifice 2.1 and arranged in packages 3 through which is threaded a single tube 1 which is then bent of the desired way to form the heat exchanger.

Of course, various modifications and variants may be made by those skilled in the art to the device described above and by way of nonlimiting example, without departing from the scope of the invention.

Claims (4)

Heat exchanger characterized in that it is constituted by a series of elementary fins (2) provided with an orifice (2.1) and grouped in packages (3) through which a tube (1) is threaded passing through the orifices (2.1), tube in which the refrigerant must flow; these packages (3) being distributed leaving free areas in the tube (1) to allow bending the latter in said free areas. Heat exchanger according to claim 1, characterized in that it comprises lateral flanges (4) provided with orifices (4.1) for the passage of the ends of the tube (1) and grooves (4.2) for the passage of the curved areas of the tube (1). Heat exchanger according to claim 1, characterized in that it is associated with other heat exchangers to form modular batteries and in that several basic batteries can be combined to form larger groups. Method of manufacturing the heat exchanger according to any one of claims 1 to 3, characterized in that the elementary fins (2) are arranged so as to form bundles (3) having the dimension, the configuration and the distribution necessary in each case, then, in a second phase, straighten the tube (1) and pass it inside the packets (3), through the orifices (2.1), this second phase ending with expansion of the tube (1) to ensure effective contact between this tube and the elementary fins (2), then, in a third phase, the tube (1) is bent to the desired shape so that the different packages (3 ) are placed in juxtaposed positions, according to vertical stacks and / or horizontal stacks, and, finally, the flanges (4) are mounted.

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