EP1300644A2 - Heat exchanger and process to fabricate this heat exchanger - Google Patents

Abstract

The heat emitter with a collection tube is particularly for a carbon dioxide circuit and feeds several flat tubes with a medium participating in the heat emission. Flat tubes (11) are inserted in a channel (1) formed as collection tube, the ends (11') of which inserted between the edges (5) are turned through 90 degrees in relation to the remaining tube section. <??>With such a formation, the flat tubes can be flowed through in a specific direction (arrow 12). The intermediate spaces between the flat tubes can be provided with ribs, in order to improve heat transmission. The collection tube can be divided lengthwise by dividing walls and provided with inflow and outflow apertures.

Description

The invention relates to a heat exchanger, in particular for a CO ₂ circuit, with a collecting tube which serves to act on a plurality of tubes or flat tubes with a medium involved in the heat transfer. The invention also relates to a method for producing such a heat exchanger with at least one collecting tube.

It is known to provide heat exchangers with flow-through pipes, which usually, even if flat tubes are used, with their ends are kept tightly sealed in tubesheets, in particular the tube bottom then from a hood-like collection box is covered, which is used to supply the involved in the heat transfer Medium serves.

Collecting boxes of this type are known for example from DE 40 28 438 A1 known. It is also known (DE 37 01 865 A1), a manifold directly through the juxtaposed flared ends of Flat tubes or the like to form or prefabricated pipes as Use manifolds that are machined with openings be provided for insertion of the flat tube ends (DE 199 45 223 A1). The manufacturing cost of such headers is because of the necessary editing very big, to that comes before the soldering about any remaining chips are carefully removed In order to prevent leaks due to unwanted burring in the avoid later soldering. There is also the danger that Chips lead to malfunctions of the refrigerant circuit.

The present invention is therefore based on the object, a Heat exchanger with a manifold so that he in easy way to produce and also in a simple way with flat tubes can be equipped.

To solve this problem is in a heat exchanger with manifold of the type mentioned provided that the manifold characterized by a shaped to a channel sheet metal strip is, whose edges are substantially parallel to a longitudinal center plane run the channel and form an open gap for recording the free ends of the flat tubes is used.

This configuration makes it possible in a simple manner without any Machining, flat tubes with each other through the Connecting collecting tube, wherein the gap shaped edges for form the soldering process suitable contact surfaces on the flat tube ends.

In a further development of the invention, the metal strip on its inside be soldered, if he, what will be discussed, from a Flat material is formed. This embodiment also offers the possibility to simplify the soldering process.

In a further development of the invention, the edges of the metal strip diverge outwards and so an insertion bevel for the flat tubes form, which greatly facilitates the assembly process. The cross section the gutter can correspond to an omega in a particularly simple way. It results in a stable cross-section, which is also particularly simply suitable for insertion of the flat tube ends. It can the closed area of the gutter with incisions for insertion of Be provided with separating or end walls and also with openings, which can serve as inflow or outflow opening for the medium.

It is also possible, however, to provide the separation or end walls provided with recesses corresponding to the cross section of the channel, Preferably, therefore, the Omegaquerschnitt, correspond and in Let slide longitudinally onto the gutters, so that the arrangement incisions, optionally retrospectively in the manifold must be provided, is not necessary, and the at the same time the space between ribs and supply pipes against misguided air block. It will be shown later, however, that Such incisions or openings even before the transformation of the Blechstreifens introduced to its channel shape by punching so that even then a machining can not is required.

In a further development of the invention, the flat tubes can be twisted by 90 ° Ends are inserted into the gap, with the twisted ones Ends of several flat tubes in the interior of the channel directly to each other abut and so set the distance of the individual flat tubes. At the same time but also the distance of the twisted outer part the flat tubes are each chosen from the free end so that the twisted Part immediately as a stop at the edges forming the gap can serve. Also towards the axis of the gutter is on this Way an alignment of the flat tubes possible without separate Measures must be taken.

As previously indicated, it is particularly advantageous for the production the collection tube to provide a method in which as the starting material a flattened on at least one side soldered flat Sheet metal strip is provided, with the solder-plated side inside is bent to the groove, the edges of at least one Make a distance to each other, the one on the strength of forms a split gap to be inserted flat tubes. Such Production also makes it possible in a simple manner, in the first to provide even flat sheet metal stampings, which after the forming of such a metal strip to its final form, which for example, in a multi-stage or progressive composite press tool can happen, the incisions for inserting the separation or End walls or the inflow and outflow openings for the medium form. Incidentally, the embodiment can also be made in such a way that after inserting the free flat tube ends in the gap between the edges the later solder joint a certain distance to the flat tube end, thereby avoiding that Lot flows into the flat tube channels by capillary forces. In the preparation of can also be used before the soldering process for Dichtlötung between the flat tubes still a solder foil or a thin solder coated sheet inserted become.

Fig. 1

einen Teil eines zur Herstellung eines Sammelrohrs vorgesehenen flachen Blechstreifen,

Fig. 2

einen Abschnitt des aus dem Blechstreifen durch Umbiegen gebildeten Sammelrohres,

Fig. 3

das durch eingesetzte Trennwände in einen Zu- und in einen Abführabschnitt unterteilte Sammelrohr,

Fig. 4

eine perspektivische Darstellung eines Sammelrohrendes im noch nicht verschlossenen Zustand mit einem eingesetzten Sammelrohr,

Fig. 5

eine Darstellung ähnlich Fig. 4, jedoch mit einer eingesetzten Trennwand,

Fig. 6

eine Darstellung ähnlich Fig. 4, jedoch mit mehreren eingesetzten Flachrohren, deren Enden um 90° gegenüber den anderen Abschnitten verdreht sind,

Fig. 7

einen schematischen Längsschnitt durch einen Wärmeübertrager nach Fig. 6 mit eingesetzten Flachrohren,

Fig. 8

ein Sammelrohr ähnlich Fig. 4, jedoch mit einem Omegaquerschnitt zur Bildung einer Einführschräge,

Fig. 9

eine schematische Seitenansicht eines Teiles eines Wärmeübertragers, bei dem ein Sammelrohrquerschnitt nach Fig. 8 vorgesehen ist,

Fig. 10

die Ansicht eines der als Abschlusswand vorgesehenen Bleche der Fig. 9,

Fig. 11

eine Trennwand ähnlich Fig. 10, jedoch mit mehreren Aussparungen zur Nebeneinanderanordnung mehrerer Sammelrohre und

Fig. 12

ein Ausführungsbeispiel eines Wärmeübertragers mit mehreren nebeneinander liegenden Sammelrohren und einer Rohrausbildung in Serpentinenform.

The invention is illustrated by means of embodiments in the drawing and will be explained in the following. Show it:

Fig. 1

a part of a flat metal strip intended for the production of a collecting pipe,

Fig. 2

a portion of the collection tube formed by bending the sheet metal strip,

Fig. 3

the collecting tube, which is divided by an inserted dividing wall into an inlet and a discharge section,

Fig. 4

a perspective view of a header end in the not yet closed state with an inserted manifold,

Fig. 5

a representation similar to FIG. 4, but with an inserted partition,

Fig. 6

a representation similar to FIG. 4, but with several inserted flat tubes whose ends are rotated by 90 ° relative to the other sections,

Fig. 7

3 shows a schematic longitudinal section through a heat exchanger according to FIG. 6 with inserted flat tubes, FIG.

Fig. 8

a collection tube similar to FIG. 4, but with an omega cross section to form an insertion bevel,

Fig. 9

FIG. 2 a schematic side view of a part of a heat exchanger in which a manifold cross-section according to FIG. 8 is provided, FIG.

Fig. 10

the view of one of the provided as the end wall panels of FIG. 9,

Fig. 11

a partition similar to FIG. 10, but with a plurality of recesses for juxtaposing a plurality of manifolds and

Fig. 12

an embodiment of a heat exchanger with a plurality of juxtaposed headers and a tube formation in serpentine form.

In Fig. 1, a piece of a flat sheet metal strip 1 'is shown, the for producing a manifold according to the present invention is provided. This sheet metal strip 1 'is with a slot-shaped Punching 2 and with a round also punched-out opening 3 Provided. The metal strip 1 'is facing away from the viewer Bottom lotplattiert in a manner not shown.

It is bent in the direction of the arrows 4 and in the shape of FIG. 2 where it is transformed into a downwardly open channel 1. This Channel can, for example, the cross-sectional shape of FIG. 4, and it has one-sided protruding, mutually approximately parallel edges 5, which form between them a gap 6 (see also Fig. 3), the is exploited to the ends of a flat tube 7 - Fig. 4 - record. These ends 7 'are only slightly over the narrowest point of the Slit 6 upwards. When the gutter 1 is used as a manifold is, in this way, the guided through the manifold at the Heat transfer involved medium in the open, in the interior the gutter 1 einragenden flat tubes 7 enter. The ends 7 'of Flat tubes 7 are soldered to the edges 5, so that a dense Can accommodate flat tubes, without a manifold provided with insertion openings by mechanical processing must become.

The ends or at least one end of a gutter may be at least one Bevel 20 in the direction of the inserted flat tubes, the serve as insertion aid for the flat tubes.

FIGS. 3 and 5 make it clear that the channel 1 is relatively simple Way a collection tube can be formed when partitions 8 divide different sections of the channel against each other and for example one of the openings 3 as an inflow opening to the manifold flows in the direction of the arrow 9 and another opening 3 in another portion of the manifold as a drain opening to the outflow used in the direction of arrow 10. The partitions 8 are inserted into the slot openings 2, which are so dimensioned are that the lowest point of the slot 2 in the final shape of the channel. 2 according to Fig. 3 or Fig. 5 with the beginning of the end 7 'of the flat tube coincides. The partition 8, for example, as a solder-plated flat sheet is formed, can then be inserted into the slot 2 and then soldered in the channel 1, wherein the flat tubes 7 with the edges 5 of the gutter are soldered tight, so that a Heat exchanger can be formed, the flat tubes in not be shown in detail by one of the media to be flown, the participates in heat transfer while the second medium through the manifold, i. through the channel 1 and through the flat tubes 7 flows. The partitions preferably have cutouts 21, which can at least partially take the pipes.

Fig. 6 shows a variant of a heat exchanger in so far as here Flat tubes 11 inserted into the groove formed as a collecting channel 1 are, whose inserted between the edges 5 ends 11 'respectively are rotated by 90 ° relative to the rest of the pipe section. How can be readily apparent, in such an embodiment the flat tubes 11 are flowed through in the direction of the arrow 12. It exists Of course, the possibility of the spaces between the Flat tubes 11 provided with ribs to the heat transfer to improve. For the rest, can be formed by the channel 1 collection tube in the same way by partitions 8 in its length divide and provided with inflow or outflow 3, as the was explained with reference to FIGS. 1 to 5. The production of the gutter 1 is also done in the same way.

FIG. 7 shows in this context that the in the Trough 1 inserted ends 11 'of the flat tubes 11 in abutment lie and so does the distance between the individual flat tubes 11 can be met in a simple manner.

FIG. 8 shows a variant of the collecting tube designed as a channel insofar as here the edges 5a diverge outwards and only lie in an area on the flat tubes 7, something of the free End of the edge is removed. The edges 5a form in this way in each case an insertion bevel for the free ends of the flat tubes. 7 At the same time with twisted pipe ends the engagement or insertion depth The pipes limited because by turning the pipe ends the Width of the pipe ends with increasing distance from the pipe end grows. The soldering takes place in the contact area of the edges 5a with the Flat tubes 7 instead.

Figs. 9 to 12 illustrate another way of attaching End walls for the trained as a gutter 1 collection tube. Here Be lotplattierte plates 13 with a recess 16 in the cross-sectional shape made the channel 1, which then after the flat tube 14 or more flat tubes are inserted into the channel, from the outside be pushed onto the channel 1, until they on the or abut the flat tubes. In this position, the sheets 13 are then soldered together with the flat tube and the channel 1.

This embodiment also opens up the possibility of several such To arrange recesses 16 in a common plate 15, the then, as shown in FIG. 12, as a side plate of three side by side lying collecting pipes in the form of grooves 1 is usable and For example, the production of a serpentine heat exchanger with in loops laid flat tubes 17 and 18 allows.

Of course, other cross-sectional shapes for the channel 1 are conceivable. Decisive in each case is that the free edges of the channel form a gap whose width is matched to the strength of the flat tubes to be used. The embodiments shown in the drawing are particularly suitable for heat exchangers for a CO ₂ refrigeration cycle.

Figure 12 also shows a cover strip 22, which serves to that as little false air is generated.

Claims (19)

Heat exchanger with a manifold, in particular for a CO ₂ circuit, which serves for acting on a plurality of flat tubes with a medium involved in the heat transfer, wherein the manifold is characterized by a shaped to a groove sheet metal strip, the edges of which extend substantially parallel to a longitudinal center plane of the groove and form an open gap which serves to receive the free ends of the flat tubes. Heat exchanger according to claim 1, characterized in that the edges of the channel form an angle α between 0 and 90 degrees. Heat exchanger according to one of the preceding claims, characterized in that a chamfer is arranged on at least one of the edges of the channel at an end region. Heat exchanger according to claim 1, 2 or 3, characterized in that the sheet metal strip is solder-plated on its inside. Heat exchanger according to claim 1, 2, 3 or 4, characterized in that the edges of the trough-shaped metal strip diverge outwardly and form an insertion bevel for the flat tubes. Heat exchanger according to any preceding claim, characterized in that the cross-section of the channel resembles or corresponds to an omega or is round or elliptical or oval, each with two edges projecting therefrom. Heat exchanger according to at least one preceding claim, characterized in that the closed region of the channel is provided with incisions for inserting separating and / or end walls. Heat exchanger according to at least one preceding claim, characterized in that a closure wall and / or partition wall engages in a plurality of recesses of grooves. Heat exchanger according to at least one preceding claim, characterized in that a closure wall engages or closes in a plurality of grooves. Heat exchanger according to at least one preceding claim, characterized in that a closure wall engages in a plurality of recesses of grooves. Heat exchanger according to at least one preceding claim, characterized in that the closed region of the channel is provided with openings as inlet or outlet opening for the medium. Heat exchanger according to at least one preceding claim, characterized in that end walls are provided with recesses which correspond to the cross section of the channel and are pushed longitudinally onto the channel. Heat exchanger according to at least one preceding claim, characterized in that the flat tubes are inserted with twisted by 90 ° ends in the gap. Heat exchanger according to at least one preceding claim, characterized in that the twisted ends of a plurality of flat tubes in the interior of the channel abut one another. Heat exchanger according to at least one preceding claim, characterized in that the distance between the twisted main part of the flat tubes from the free end of the pipe ends is selected in each case so that the twisted main portion serves as a stop on the gap. A method for producing a heat exchanger, in particular according to claim 1, characterized in that the starting material is provided at least on one side solder-plated flat sheet metal strip which is bent with the solder-plated side inwardly to the channel whose edges have at least at one point a distance from each other , which forms a tuned to the strength of einzuschiebenden flat tubes gap. A method according to claim 16, characterized in that the distance of the edges is less than the height of the flat tubes, which are inserted into the channel, so that the pipe ends are received with tension in the channel. A method according to claim 17, characterized in that the distance is preferably 0.1 mm to 1 mm less than the height of the flat tubes. Method according to one of the preceding claims, characterized in that punches are provided in the sheet metal strip, which form the incisions for inserting separating or end walls or the inflow and outflow openings for the medium after bending.

Images