EP0845648B1 - Flat tube heat exchanger, particularly serpentine condenser - Google Patents

Description

The invention relates to a flat tube heat exchanger with a flat tube block with one or more Flat tubes with their two end sections in one each terminal compartment component open with at least one end section is twisted section relative to the flat tube. Such heat exchangers can be used, for example, as serpentine-type capacitors use in air conditioning systems of motor vehicles.

Such a heat exchanger is in US Pat. No. 3,416,600 of the serpentine type in which a stack is disclosed serpentine curved flat tubes is provided, which in their end sections are twisted by 90 ° so that the longitudinal axis of the twisted end sections with the longitudinal axis of the not twisted flat tube middle section coincides. With these twisted end sections are the flat tubes in associated side collecting tubes inserted, this with circumferential introduced in the pipe longitudinal direction and longitudinal slots arranged in a line are provided. In addition, the flat tubes can be in a middle area be twisted by 180 °. To form the serpentine flat tube stack are the individual serpentine curved Flat tubes arranged side by side in the same position. Thereby each have an inlet-side flat tube section a flat tube and an outlet-side section of a opposite flat tube opposite. Because in the operation of the heat exchanger these two opposite sections generally at significantly different temperatures lie, there may be undesirable heat transfer effects come between these flat tube sections, the efficiency reduce the heat exchanger.

The invention is a technical problem of providing a flat tube heat exchanger of the type mentioned Type based on low dead volume, high efficiency, sufficient burst pressure security and given Manufacture flat tube width comparatively small depth lets and if necessary in particular as a capacitor for a Air conditioning is usable.

The invention solves this problem by providing it a flat tube heat exchanger with the features of the claim 1.

In the heat exchanger according to claim 1, it is specially provided that at least one of the two end portions of each Flat tube is eccentrically, eccentrically twisted, i.e. that the longitudinal axis of the twisted end section opposite the Longitudinal axis of the undistorted flat tube middle section in is offset in a lateral direction.

By twisting the flat tube ends, their transverse extension can be made with the passage cross-section kept essentially constant Reduce. This allows the side Terminal compartment components, e.g. corresponding manifolds, with a construction depth that is only slightly larger than the reduced transverse extension of the twisted flat tube end needs to be and, for example, smaller than the construction depth which can be flat tubes. The small depth of the connection space components has the further advantage that the same for Achieving a predetermined burst pressure safety with relative Small wall thickness can be made and only a relative have low dead volume. You can also do that Flow through heat exchanger volume for a given heat exchanger output keep comparatively low, what if necessary a reduction in the volume of the heat transfer fluid flowing through compared to conventional flat tube heat exchangers allowed.

The off-center twisting of the flat tube ends creates the Prerequisite for realizing even more compact designs of the Heat exchanger. So with appropriate lateral displacement neighboring, in each case the same terminal compartment component the end of the flat tube end sections the distance of the flat tubes in the non-twisted middle area even with a torsion angle 90 ° smaller than the flat tube width, without the flat tubes in their central areas must be laterally offset. Besides, can by corresponding cross-displacement of the twisted flat tube ends A heat exchanger is implemented in the depth direction of the pipe block be in which the terminal compartment components on one side of the pipe block are arranged.

In one embodiment of the invention according to claim 2 are at least two adjacent end sections in a row Flat tubes twisted so that their longitudinal axis perpendicular to Plane of the undistorted flat tube middle section, i.e. in a pipe block vertical direction, opposite the longitudinal central axis of the undistorted flat tube middle section is offset. The two adjacent flat tubes are like this in the flat tube block arranged that they are offset from each other in the vertical direction open twisted ends in the same terminal compartment component. The opposing twisting of the two Flat tube ends allow the two adjacent flat tubes despite the end twisting with comparatively little Distance from each other. This is how it can be realized of the flat tube block as tube / fin block the distance of the two flat tubes even when twisted at the end 90 ° in the flat tube middle section to the level of a normal one Corrugated fin remain limited without an unusually high one Corrugated fin or a double corrugated fin complex is required.

In one embodiment of the invention according to claim 3 is a lateral offset of the twisted flat tube end sections opposite the flat tube middle section in the plane of not twisted flat tube middle section, i.e. in a pipe block depth direction, intended. This enables if necessary e.g. the realization of heat exchangers in which serpentine Flat tubes with both ends on the same tube block side open into the two terminal compartment components, the there separately or integrated into a single component Block vertical direction.

In the heat exchanger according to claim 4, the have the features of one or more of claims 1 to 3 can is a tube block from a stack of serpentine Flat tubes are provided, which are arranged so that in the stack of adjacent flat tubes always either with their inlet-side or with their outlet-side sections contiguous. If the volume is as small as possible is desired for the terminal compartment components, can this is advantageous by suitable twisting of the flat tube ends, according to one of claims 1 to 3, with a corresponding off-center twisting maintain a small distance between adjacent flat tubes can be.

Fig. 1

eine teilweise Seitenansicht eines Flachrohrs mit rechtwinkliger, in Hochrichtung außermittig versetzter endseitiger Tordierung zur Verwendung in einem Flachrohr-Wärmeübertrager,

Fig. 2

eine schematische Seitenansicht eines Flachrohr-Kondensators vom Serpentinentyp, in welchem gemäß Fig. 1 tordierte Flachrohre verwendet sind,

Fig. 3

eine Seitenansicht entsprechend Fig. 1, jedoch für den Fall einer in Tiefenrichtung, d.h. in der Ebene des nicht tordierten Flachrohrmittelabschnitts, versetzten Tordierung des Flachrohrendabschnitts,

Fig. 4

eine schematische Draufsicht auf einen Teil eines weiteren Beispiels eines Wärmeübertragers vom Serpentinentyp mit serpentinenförmigen, in zwei seitengleiche Anschlußraumbauteile einmündenden Flachrohren und

Fig. 5

eine teilweise, stark schematisierte, perspektivische Darstellung eines mit Flachrohren entsprechend Fig. 4 realisierten Kondensators.

Advantageous embodiments of the invention are shown in the drawings and are described below. Here show:

Fig. 1

2 shows a partial side view of a flat tube with a right-hand twisting at the end, which is offset off-center in the vertical direction, for use in a flat tube heat exchanger,

Fig. 2

2 shows a schematic side view of a flat tube condenser of the serpentine type, in which twisted flat tubes are used according to FIG. 1,

Fig. 3

2 shows a side view corresponding to FIG. 1, but in the case of a twisting of the flat tube end section offset in the depth direction, ie in the plane of the non-twisted flat tube middle section,

Fig. 4

is a schematic plan view of part of a further example of a heat exchanger of the serpentine type with serpentine-shaped, in two parallel connection space components opening flat tubes and

Fig. 5

a partial, highly schematic, perspective view of a condenser realized with flat tubes according to FIG. 4.

Various heat exchangers and associated ones are shown in the figures Shown flat tube designs, for better Orientation in each case a Cartesian xyz coordinate system is specified, in which the x-axis is a longitudinal direction of a respective tube blocks or the associated flat tubes, the y-axis is a block or pipe vertical direction and the z-axis denote a block or pipe depth direction.

Fig. 1 shows an end flat tube twisting, in which the flat tube end section 3 opposite the flat tube middle section 2 is twisted by 90 ° and off center in such a way that the longitudinal axis 1 of the twisted end section by a selectable Amount dy with respect to the longitudinal axis 4 of the und twisted Middle section 2 in the vertical direction defined above, i.e. perpendicular to the plane of the undistorted flat tube middle section 2, is offset.

Fig. 2 shows e.g. as a condenser in a motor vehicle air conditioning system usable flat tube heat exchanger from Serpentine type, in which twisted according to FIG. 1, serpentine Flat tubes 5 are used. The heat exchanger contains a tube / fin block in which the serpentine, flat tubes 5 in. each having four bends a stack successively arranged in the vertical direction y are, in the spaces between adjacent Flat tube middle sections 2 introduced heat-conducting corrugated fins 30 are. Each flat tube 5 opens with its two according to Fig. 1 twisted off-center in the vertical direction End sections 3 on opposite long sides of the tube / fin block into a collecting pipe running longitudinally there 6, 7 a. The manifolds 6, 7 act as connection space components, one of which has an end face Inlet 8 and the other via a corresponding end face Outlet 9 has. This can be a heat transfer fluid 10 fed via the inlet 8 into a collecting tube 6 be where it opens into this manifold 6 Flat tube ends in the entry-side section 11 each Flat tube is forwarded to then through the respective to flow through the serpentine flat tube and from it outlet-side flat tube section 12 over those twisted flat tube ends to get into the other manifold 7, from which it flows out via the outlet 9.

As can be seen from Fig. 2, adjacent flat tubes are always arranged so that they are either with their entry-side Sections 11 or with their outlet-side sections 12 face each other. Because these sections with each other are each at practically the same temperature no undesirable heat transfer effects between fluid, that flows in a flat tube, and fluid that flows in an adjacent one Flat tube flows on, causing a corresponding deterioration the efficiency of the intended heat transfer between the heat transfer fluid 10 on the one hand and one perpendicular to the plane of FIG. 2 by the Pipe / fin block medium flowing through, e.g. Air, avoids. It is through this special arrangement of the flat tubes 5 also no special measures for thermal insulation from opposite sections of adjacent Flat tubes are required, as in conventional arrangements It is expedient, in each case the entry side Section of a flat tube an outlet-side section opposite of the other flat tube.

Due to the arrangement of the flat tubes 5 with opposite inlet-side or outlet-side sections, are the twisted end sections 3 accordingly two adjacent flat tubes 5 directly adjacent to each other. The twisted flat tube ends 3 consequently each open in groups of two directly adjacent pipe ends, which of the next group of two by twice the flat tube expansion are spaced in the vertical direction, in the respective manifold 6, 7 a. Appropriate, off-center twisting accordingly Fig. 1 ensures that the distance between the not twisted middle sections of two neighboring inlet-side or outlet-side pipe sections 11, 12 is not larger, but is just as large as the distance between the remaining, not twisted flat tube middle sections 2 of the serpentine flat tubes 5. This has the consequence that the same corrugated fins between two adjacent flat tubes 5 30 can be used as between the middle sections 2 of each serpentine flat tube 5.

For this purpose, there are two adjacent flat tube end sections twisted at right angles 3 opposite in the vertical direction y offset, i.e. in Fig. 2 the one pipe end up and that other pipe end down. This makes it possible, despite the right-angled twisting of the flat tube ends corrugated fins use, the height of which may be less than that if necessary Width, i.e. Depth of the flat tubes 5. From a simple geometric Consideration shows that the amount dy at lateral displacement of the twisted pipe end sections 3 greater than half the difference between flat tube width and Corrugated fin height is to be selected, i.e. for a given flat tube width B and given corrugated fin height W applies dy> (B-W) / 2. The Compliance with this condition allows one in the longitudinal direction of the block aligned arrangement of the on the block side concerned outflowing flat tube ends 3 and accordingly one aligned insertion of the corresponding push-through slots in the manifolds 6, 7. The rectangular one chosen in this example Twisting of the flat tube ends 3 allows on the other hand achieving a minimal overall depth for the header pipes 6, 7, whose diameter is only slightly larger than the thickness the flat tubes 5 need to be. The manifolds 6, 7 can are kept so small in their cross-section in this way, that they are not in the depth direction over the tube / fin block stand out, but noticeably if necessary can be designed narrower. Alternatively, it goes without saying also twisting of the flat tube ends by less than 90 ° and / or with additional displacement in the depth direction possible.

3 to 5 show application examples in which the Twisting the flat tube ends a lateral displacement in the Depth direction z includes. Fig. 3 shows a section such a flat tube with a non-twisted middle section 13 and in contrast twisted end section 14. As from FIG. 3 can be seen, the pipe end section 14 opposite the pipe middle section 13 at an angle of 90 ° and with an offset twisted by an amount dz, i.e. the longitudinal axis 15 of the twisted end section 14 is from the longitudinal axis 16 of the Middle section 13 by the amount dz in the z direction of selected coordinate system, i.e. in the pipe or block depth direction, added.

Fig. 4 shows a partial plan view of a tube / fin block with flat tubes 17 and between adjacent ones Flat tube middle sections lying corrugated fins 18, in which the flat tube ends are twisted according to FIG. 3. specially the flat tubes 17 are serpentine in this example designed so that they have both ends 19a, 19b on the same Block side open. The two end regions 19a, 19b are twisted in opposite directions in the z direction, i.e. the Both end regions 19a, 19b are symmetrical with their longitudinal axes to the longitudinal axis 20 of the non-twisted tube middle section 21 each removed from it by the amount dz. Correspondingly, there is the Longitudinal axis 20 of the non-twisted flat tube middle sections 21 in the longitudinal direction of the block, i.e. Block vertical, trending Collector tube 22, 23, of which in turn the one as Distribution channel and the other acts as a collection channel. each Flat tube 17 of the tube / fin block opens with his one twisted end portion 19a in a manifold 22 and with the other end region 19b into the other manifold 23.

With the heat exchanger realized in this way, like him especially as a condenser for a motor vehicle air conditioning system can be used, the two are thus Collecting tubes 22, 23 running longitudinally on the same block side. Through the right-angled flat tube ends 19a, 19b, the manifolds 22, 23 can in turn be used produce a relatively small diameter so that they are both together side by side, as can be seen from FIG. 4, not project significantly beyond the depth of the tube / fin block. As an alternative to the arrangement of two separate header pipes shown the two can act as a collection or distribution channel Terminal compartment components in a common terminal compartment component be integrated, which has two chambers, the are separated by a longitudinal partition and in which each flat tube ends with one end.

Fig. 5 shows a detail of a perspective schematic sketch in a side view a modification of the tube / fin block of Fig. 4. In this variant there is a stack serpentine flat tubes 24 provided with their Ends on the same block side in two side by side Collecting pipes 25, 26 open. The two manifolds 25, 26 lie here again offset next to each other in the block depth direction, as is the case with the heat exchanger of FIG. 4. From Fig. 5 it is clear that in this heat exchanger Flat tubes 24 corresponding to the heat exchanger of Fig. 2 so are arranged so that they are either with their entry-side Pipe sections 27 or their outlet side Pipe sections 28 are opposite. This has the above too Fig. 2 described advantage of avoiding heat transfer losses noticeable between adjacent pipe sections different temperature. This means that the variant 5 which open into the respective manifold 25, 26 Ends of the adjoining inlet-side or outlet-side pipe sections 27, 28 of adjacent flat pipes 24 again relatively close to each other.

In order now undesirable on the one hand according to the example of FIG. 2 large distances between adjacent flat tubes too avoid and on the other hand according to Fig. 4 the arrangement of the two manifolds 25, 26 on the same side of the tube / fin block to allow with a small manifold dead volume, the flat tubes 24 are rectangular in their end sections and combines both in the vertical direction y and in the deep direction z staggered. The displacement in the block vertical direction y is implemented in accordance with the example of FIG. 2, i.e. of the two twisted pipe ends, two neighboring ones Flat tubes 24 is one in positive and the other in the negative y direction by an appropriate amount with respect to the longitudinal axis of the flat tube middle section added. This allows adjacent flat tubes 24 to be used comparatively short distance with the interposition of a Arrange a simple corrugated fin. The additional transfer of the twisted pipe ends in the depth direction z allows the in arrangement of the two header pipes offset in this direction 25, 26 corresponding to FIG. 4.

A twisting of the offset in the block depth direction z Flat tube end area opposite the flat tube middle section can also be advantageous for straight line heat exchangers Use flat tubes on opposite tube block sides open into a respective terminal compartment component. Because by such a twisted transfer need equilateral Ends of adjacent flat tubes in the block vertical direction not be spaced apart, but can be in the block depth direction partially overlap. This can, for example the distance of the flat tubes in their middle section and thus the height of any corrugated ribs to be introduced there despite a right-angled twisting of the flat tube ends noticeably smaller than the width, i.e. Depth, the rectilinear Flat tubes are held. In the associated terminal compartment component in this case two are offset in the block depth direction Rows of through-slots spaced from one another in the block direction provided for inserting the pipe ends.

The flat tube heat exchangers described above can be due to the properties mentioned for a given, required Heat transfer performance very compact and with comparative manufacture with little effort. It should be noted here in particular also that for the construction of the respective tube / fin block only one type of flat tube is required which is identical or in a 180 ° around the x-axis tilted position successively arranged in the tube block stack become. It is understood that in addition to those described Examples of further implementations of the invention Flat tube heat exchanger are possible, in particular also those with straight instead of serpentine flat tubes and with end twisting by less than 90 ° and / or any combination of up and down twisting offset by a desired amount. It further understood that the heat exchanger according to the invention is usable in all areas where traditionally Flat tube heat exchangers are used.

Claims (4)

1. A flat tube heat exchanger, especially a serpentine condenser, with:

   a flat tube block with one or more flat tubes (5) whose two end sections (3) end in a corresponding connection chamber component (6, 7), whereby at least one end section (3) is twisted in relation to the flat tube middle section (2),

   characterized in that

   at least one of the two flat tube end sections (3) is twisted off center in such a way that its longitudinal axis (1) is offset in a lateral direction (y, z) from the longitudinal axis (4) of the middle section of the flat tube (2).
2. A flat tube heat exchanger according to claim 1, further
   characterized in that the flat tube block contains a stack with several straight or serpentine flat tubes (5), whereby at least one pair of end sections (3) of adjacent flat tubes (5) ending on the same side are twisted off center in such a way that the two longitudinal axes of the twisted flat tube end sections are offset in opposite directions relative to the longitudinal axis of the flat tube middle section and parallel to the stack direction.
3. A flat tube heat exchanger according to claim 1 or 2, further characterized in that the flat tube block contains a stack of several straight or serpentine flat tubes (17) whose two respective end areas (19a, 19b) end on opposite tube block sides or on the same tube block side, whereby at least one part of the end areas (19a, 19b) is twisted and offset relative to the longitudinal axis (20) of the flat tube middle section (21) in the lateral direction (z) parallel to the plane of the flat tube middle section.
4. A flat tube heat exchanger according to one of claims 1 to 3, further characterized in that the flat tube block contains a stack with several serpentine flat tubes (5) whose two end sections end on opposite tube block sides or on the same tube block side in a corresponding connection chamber component running along the respective tube block side, whereby in each case two adjacent flat tubes are arranged in such a way that an inlet side tube section of one flat tube is adjacent to an inlet side tube section of the other flat tube, or an outlet side tube section of one flat tube is adjacent to an outlet side tube section of the other flat tube.

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