EP1213556B1 - Flat tube heat exchanger with deformed tube ends - Google Patents

Description

The invention relates to a heat exchanger constructed from flat tubes, in which the flat tubes on at least one, in a connection space forming Component, e.g. a distributor and / or manifold, opening end portion are transformed.

From flat tubes constructed heat exchanger, in which the flat tubes with non-formed end portion parallel in a connection space forming component, as a manifold and / or a manifold, for example, become used as condensers and evaporators in vehicle air conditioners. The term flat tube heat exchanger should also be present here Heat exchangers are to be understood in disk construction, in which rectangular, elongated, hollow discs are used as "flat tubes", through the interior of which the refrigerant of the air conditioner is passed. In these conventional heat exchangers with over their entire length rectilinear flat tubes is the inner diameter of the terminal compartment forming component determined by the width of the flat tubes. With larger flat tube width is thus a larger inner diameter for this Required component, so that its realization a greater wall thickness is required if the bursting strength is to remain the same size. Using of pipes as connecting space forming components also occurs the Difficulty that with increasing flat tube width and thus growing Diameter of the connecting space forming tubes whose dead volume increases. In any case, the width of the connection space-forming component is at these conventional heat exchangers to choose larger than that of the flat tubes.

Patent EP 0 565 813 B1 describes a heat exchanger which composed of a plurality of tubes with preferably oval cross-section is the end in triangular openings of a bottom plate of a Used collecting tank and for this purpose at its Rohrendabschnitt in a triangle shape are transformed. After inserting the triangular pipe end sections in the triangular openings of the bottom plate are the Tube ends widened to the tubes at the respective bottom plate of two Set collecting tanks arranged on both sides.

In the published patent application EP 0 659 500 A1 a heat exchanger is disclosed, the of several, spaced superimposed, U-shaped bent Flat tubes is constructed. The two legs of the U-shaped Flat tubes with respect to their connection area twisted by 90 °, so they both lie in a common transverse plane. One free end of the flat tubes is to a distribution channel and the other free end to one Collector channel connected, with distribution and collection channel on the same Heat exchanger side are arranged and introduced via the distribution channel Heat transfer medium U-shaped parallel through the individual flat tubes flows to the collecting channel.

US Pat. No. 3,416,600 discloses a serpentine type heat exchanger discloses in which a stack of serpentine curved flat tubes is provided is, which are twisted in their end sections by 90 °. With these twisted End sections are the flat tubes inserted into associated manifolds, the this with circumferentially introduced, extending in the tube longitudinal direction and are provided spaced apart longitudinal slots. In addition, you can the flat tubes are twisted in a central area by 180 °.

In the published patent application FR 2 712 966 A1 is a flat tube heat exchanger described, the flat tubes in their in a connection space-forming component opening end portion on one opposite its subsequent section smaller transverse extent bent or unequal by an angle α 90 ° twisted.

The invention is the technical problem of providing a flat tube heat exchanger based on the type mentioned, a comparatively has low dead volume in the connection space, given a wall thickness the connection space forming component high bursting security has, given a flat tube width with a comparatively small overall depth manufacture and, if necessary, in particular as a condenser for an air conditioner is usable.

The invention solves this problem by providing a flat tube heat exchanger with the features of claim 1. In this heat exchanger are the flat tubes in their in the connection space forming component opening end portion on one opposite her subsequent section lower transverse extent twisted and / or bent. You can do that Passage cross-section also in the formed end portion substantially constant hold. The smaller transverse extent of the twisted or bent Flachrohrendabschnitts compared to the subsequent flat pipe section makes it possible to make the terminal space forming member, e.g. a collection or Distributor tube to realize with a depth that is only slightly larger than the reduced transverse extension of the flat tube end section needs to be and This may be smaller than the depth of the flat tubes or at least not it needs to be bigger than the same. Both end sections can each Flat tube to be formed in the manner described, while the flat tubes in the intermediate section e.g. straight with their opposite the end sections larger transverse extent can extend, which then the depth the flat tubes and thus possibly also determines the entire heat exchanger. The achievable low installation depth of the connecting space-forming components for a given flat tube width has the further advantage that selbige to Achieving a given bursting pressure with relatively low wall thickness manufacture and have only a relatively small dead volume. In addition, the flow-through heat exchanger volume at a given Heat transfer performance comparatively low, which at Requires a reduction in the volume of the heat transfer fluid flowing through allowed compared to conventional flat tube heat exchangers.

To achieve a compact design in the direction in which the Flat tubes are arranged side by side, the Tordierung occurs during Heat exchanger according to claim 1 especially at an angle not equal to 90 °, so that the flat tube mouths are correspondingly oblique to this direction and thereby claim less installation length in this direction. Of the Torsion angle can be adjusted to the particular application. As the torsional angle increases, the depth decreases, i. Width, of the Inserting the flat tube ends required area of the connecting space forming Component, while at the same time each Flachrohrendabschnitt with a larger axial extent opens into the component.

In the flat tube heat exchanger according to claim 1 according to the invention a or a plurality of partitions provided in the connection space-forming component, the divide the terminal compartment into several subspaces. This measure can be used to the guided through the flat tubes refrigerant under redirection in a respective side terminal space forming member sequentially through successive sections of the flat tube stack. suitable for oblique Tordierung the Flachrohrendabschnitte is also the respective Partition wall with the corresponding skew angle in the connecting space forming Component arranged.

In a further developed according to claim 3 heat exchanger, the flat tubes about its longitudinal central axis or about a longitudinal axis parallel thereto twisted. In the latter case of an eccentric killing, the twisted Flat tube end sections with alternating lateral displacement in the connecting space forming Open part, so that the distance between the flat tubes in the non-twisted middle region even at a torsion angle of 90 ° less can be selected as the flat tube width, without the need for the flat tubes must be arranged laterally offset in their central areas, what would counteract a small depth.

In a further developed according to claim 4 heat exchanger with between The corrugated ribs introduced into the flat tubes are provided, the width of the corrugated ribs to choose larger than that of the flat tubes. The resulting Rib protrusion increases the efficiency of the heat-transmitting corrugated fins and protects the flat tubes against damage from the outside.

In a further developed according to claim 5 heat exchanger, the flat tubes manufactured in an advantageous manufacturing technology as extruded tubes.

The present invention further includes a flat tube heat exchanger with flat tubes, at least at one, in a connection space forming Component forming end portion are formed, wherein the Flat tubes in their opening into the connecting space-forming component end portion on a relation to their subsequent section lower transverse extent bent or twisted by an angle α not equal to 90 °, wherein one or more partitions in the connection space-forming component in one the angle α corresponding angle are arranged to the longitudinal axis, which divide the terminal space into several subspaces, in each of which a associated group of successive flat tubes opens.

For the above implementations of the invention are in particular the following further Embodiments per se or in combination possible. The flat tubes can in her opening into the terminal compartment forming member end portion centered around its longitudinal center axis or offset parallel to it Longitudinal axis be twisted off-center.

Between adjacent flat tubes corrugated fins can be introduced, the Width is greater than the flat tube width. The flat tubes can be made of extruded, before bending or twisting preferably solder- and flux-plated Be formed pipes. The respective partition may be a recess have and axially from a front end forth in the connection space forming Be used component, wherein the in the connection space forming component protruding flat tube ends engage in the partition wall recess.

Fig. 1

eine schematische Seitenansicht eines Teils eines Flachrohr-Wärmeübertragers mit schrägwinklig tordierten Flachrohrendabschnitten,

Fig. 2

eine schematische Schnittansicht längs der Linie II-II von Fig. 1,

Fig. 3

eine ausschnittweise Schnittansicht eines für einen der gezeigten Flachrohr-Wärmeübertrager verwendbaren Rohr-/Rippenblocks.

Preferred embodiments of the invention are illustrated in the drawings and described below. Hereby show:

Fig. 1

FIG. 2 a schematic side view of a part of a flat-tube heat exchanger with obliquely angled flat-tube end sections, FIG.

Fig. 2

a schematic sectional view taken along the line II-II of Fig. 1,

Fig. 3

a partial sectional view of a usable for one of the flat tube heat exchanger tube / rib block.

The shown in Fig. 1 in a fragmentary, schematic side view Heat exchanger, for example, as a condenser in a vehicle air conditioning usable. It conventionally includes a tube / rib block, in the usual way from a stack of spaced apart Flat tubes 1 and one in the spaces between the flat tubes. 1 introduced corrugated rib structure 2 consists. The tube / rib block is located between two laterally closing side plates 6, of which in the Sectional view of Fig. 1 is shown one. The flat tubes 1 are also in conventionally in its interior with one or more flow channels provided through which the refrigerant passed through an air conditioner can be. At the end, the flat tubes 1 open into one of each lateral manifold or manifold 3 formed terminal space, of which one acts as a distribution channel and the other as a collecting channel. The above an inlet led into the manifold tube flow medium is from there fed in parallel in the flat tubes 1 and traverses them to the opposite Collection tube 3, which, for example, that in Fig. 1 to be recognized Can be round tube. By means of the heat exchanger can be another, through the provided with the corrugated fin structure 2 spaces between the flat tubes 1 passed through flow medium in heat transfer connection with the flowing through the flat tubes 1 flow medium to be brought.

Characteristic of the heat exchanger shown is that the flat tubes 1 in its two end portions 1a with respect to their intermediate middle section 1b twisted by an angle α of about 60 ° about its longitudinal central axis are as shown in Fig. 2 closer. As further from this sectional view can be seen, the inserted into the respective manifold or manifold 3 run Pipe ends 1c thus obliquely both to the longitudinal axis 4 of the distributor or manifold 3 and the flat tube transverse axis Flat tube ends 1c one apart from the height, i. Width, the flat tubes 1 by the factor cosα smaller transverse extent than the heat transfer active, middle flat pipe section 1b. This means that the flat tubes 1 too only one installation area with correspondingly reduced transverse dimension, i. Reduced depth, the distributor or header 3 need. Since that Distributor or manifold 3 only a contrast slightly larger Inner diameter, this results in the advantage that the Distributor and the manifold 3 with a relatively small outer diameter R can be made, in particular, can be smaller than the transverse extent Q of the middle flat tube section 1b, thereby total the depth of the heat exchanger determines, as can be seen from the view of Fig. 2. It is understood that the manifold and the manifold 3 with corresponding oblique oblong holes for precise fitting and sealing brazing the twisted tube ends 1c are provided.

By given at a flat tube width Q compared to conventional heat exchangers this kind of smaller required inner diameter for the Distributor or manifold 3 are further achieved the advantages that selbige have relatively low dead volumes and given Wall thickness have a high bursting pressure, since their bursting strength decreases with increasing inner diameter. Conversely, can given the required bursting pressure safety, the wall thickness of the distributor and Collective tubes 3 compared to conventional heat exchangers with not deformed opening flat tube ends are reduced.

According to the invention, one or more are in one or both connection pipes 3 Partitions 16 provided to the formed by the entire connecting pipe 3 Connection space in several, in the direction of the pipe axis 4 consecutive Subdivisions 17a, 17b to divide, as shown in Fig. 2. The partition wall 16 is under a diagonal angle α of the twisted flat tube ends 1c corresponding angle oblique to the pipe axis 4 in the space arranged between two adjacent pipe ends 1c. Such Division of the respective connection space in a plurality of subspaces 17a, 17b particularly favorable for condensers, to remove the refrigerant from a subspace, e.g. the subspace 17a to feed into the flat tubes opening into it, in the opposite connection pipe into the one with the other compartment 17b deflected connected flat tubes and through the latter into this other Subspace 17b to conduct. If necessary, using multiple Partitions this flow deflection in the connecting pipes as often as desired to be repeated. In this way, the refrigerant can meander through the tube / rib block.

It is understood that in addition to the example shown with a torsion angle of approx. 60 ° alternatively every other torsion angle not equal to 90 ° for the rotation of the Flachrohrendabschnitte opposite to their subsequent flat pipe section is feasible.

It is understood that instead of the round tubes shown also distribution or Collecting boxes of any cross-section other than connecting space-forming Components are used, the one or more pieces and with curved or even, the flat tube ends be made receiving bottom can. The required pipe openings can be milled, punched, laser-cut or introduced by hydroforming and with or without Translations be realized. The flat tubes, which are specially slices of a Heat exchangers may be disc-type, for example, in one piece by extruding or by welding several pipe parts together or by forming and then welding a blank produced.

In addition to the shown straight course, the flat tubes in their area between the twisted and / or bent end sections also have a curved course. Similarly, the partitions of a used double corrugated rib structure as an alternative to the course shown vertically to the longitudinal axis of the connecting space-forming component in a acute angle to be arranged obliquely to the same. Furthermore, understands itself, that according to need the flat tubes only at one of its two end sections can be twisted and / or bent and with the other End portion then not transformed into a smaller transverse extent in a associated connection space-forming component open. The twisting Bending the Flachrohrendabschnitte can each be made so that the Passage cross section of the flat tubes also in this area substantially keep constant, which is preferred for most applications.

Instead of the shown in Figs. 1 to 2, the longitudinal center Tordierung can Flachrohrendabschnitte also off-center, i. one to its longitudinal central axis parallel offset axis, be twisted. Especially with right-angled twisting can then if necessary, the manifold and the manifold opposite be laterally offset from the intermediate tube / rib block, if the flat tubes are arranged successively such that their eccentrically twisted end portions all on one side of the median longitudinal plane lie the tube / rib block. This may be for specific installation situations be beneficial.

In another alternative, the flat tube ends may be arranged that their end sections alternately on one or the other Side of this longitudinal median plane of the tube / rib block. Suitable for that Are then in the manifold or the manifold two parallel rows To introduce longitudinal slots, the longitudinal slots of a number with lateral offset between the longitudinal slots of the other row lie. Since, due to the lateral displacement, the longitudinal slots of one row extend axially beyond the height of adjacent longitudinal slots of the other row can, the flat tubes can be even at right-angled end-side Place the twisting at a small distance in the tube / rib block. In the special case of right-angled twisting, this distance is downwards limited by half the width of the flat tubes, making it smaller in particular than the flat tube width can be. Accordingly, a small Choose height for the corrugated fins, what their heat transfer efficiency improved. This is especially true for applications in which the width the flat tubes is less than that of the corrugated fins.

3 shows a detail of a longitudinal sectional view through a tube / rib block, as usable for the heat exchangers described above is. Characteristic of this tube / rib block that the width W of Corrugated ribs 40 is greater than the width Q of the multi-chamber tubes realized Flat tubes 41. This provides a fin overhang, the the efficiency of the corrugated fins 40 in terms of their heat transfer capability increased and the flat tubes 41 against damage from the outside protects. The ratio Q / W may be, for example, 2/3.

In all the examples described above, the flat tubes can advantageously be made as extruded pipes. It can also be beneficial be the tubes before their end-end twisting or bending with a Lotund To provide flux plating. This facilitates a sealed insertion the flat tube ends in the connecting pipes by means of sealing soldering.

Claims (5)

1. Flat-tube heat exchanger with

   flat tubes (1) which are bent or turned about an angle α that is not 90° at least at an end portion (1a) opening into a component (3) forming an adjoining chamber so as to be shorter in transverse extension than their adjoining portion (1b),

   characterised in that

   one or more dividing walls (16) are provided in the component (3) forming and adjoining chamber, which divide the adjoining chamber into several part-chambers (17a, 17b), the dividing walls (16) being disposed in the intermediate space between two adjacent tube ends (1c) inclined at an angle to the longitudinal axis of the component (3) forming an adjoining chamber which corresponds to the angle α of the turned flat-tube end sections (1a).
2. Flat-tube heat exchanger as claimed in claim 1, characterised in that each co-operating group of consecutive flat tubes opens into one of the part-chambers (17a, 17b).
3. Flat-tube heat exchanger as claimed in claim 1 or 2, further characterised in that the end sections of the flat tubes opening into the component forming an adjoining chamber are turned about their longitudinal axis at the centre or about a longitudinal axis that is parallel with it but off-centre.
4. Flat-tube heat exchanger as claimed in one of claims 1 to 3, further characterised in that corrugated ribs (40) with a width (W) greater than the flat tube width (Q) are inserted between adjacent flat tubes (41).
5. Flat-tube heat exchanger as claimed in one of claims 1 to 4, further characterised in that the flat tubes are made from tubes which are extruded prior to bending or turning, preferably plated with solder and liquid means.

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