Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
  • F28F3/025—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being corrugated, plate-like elements
  • F28F3/027—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being corrugated, plate-like elements with openings, e.g. louvered corrugated fins; Assemblies of corrugated strips
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
  • F28F1/126—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element consisting of zig-zag shaped fins
  • F28F1/128—Fins with openings, e.g. louvered fins

Definitions

• the invention relates to a corrugated fin with wave crests or troughs and with adjoining, a bending edge having vertical or slightly inclined wave flanks, which are each arranged between two flat tubes in a heat exchanger, the corrugation flanks are equipped with exposed from their planes cuts. Furthermore, a heat exchanger is described which has the corrugated fins.
• corrugated fins are sometimes referred to as "flat top fins" because they have - in contrast to other corrugated fins - approximately flat (flat) wave crests or wave troughs
• the mentioned other corrugated fins have approximately semicircular wave crests and troughs, the wave flanks there usually also one have slightly greater inclination.
• Fiat top fins are often used because they are considered to be more effective than the corrugated fins with rounded wave crests or troughs with respect to good heat conducting solder joints between the wave crests or troughs and an adjacent pipe wall.
• thermally conductive compounds have a significant influence on the heat exchange efficiency between a medium flowing in the tubes and a medium flowing through the corrugated fins, which is preferably cooling air.
• Corrugated ribs are made of thin metal sheets, such as aluminum sheets.
• Metal sheets are known to have the property that when forming a bend some springback occurs, so that the formation referred to above as flat top fin does not really have flat wave crests and troughs, but is still slightly rounded. Such slightly rounded wave crests and wave troughs cause the distance from a pipe wall to the beginning of the cuts in the wave flanks is slightly larger than it actually be should.
• corrugated fins are usually arranged between two flat tubes. Although these are distances whose dimensions can be significantly smaller than 1 mm, a larger distance has a performance-reducing effect. In any event, this was determined by comparative measurements performed by the Applicant, comparing measurement results between corrugated fins of the prior art and the proposed corrugated fins described below. When brazing the heat exchanger network, one might, with some force, try to press the corrugated fins closer to the tubes to level the slightly rounded wave crests / troughs.
• the object of the invention is to further increase the power usable length of the cuts in the corrugation flanks and thus to further improve the heat exchange efficiency of a heat exchanger.
• the bending edges are formed thinned by dilution lines. It can be provided that the dilution lines are formed either over the entire bending edge continuously or intermittently therebetween.
• the dilution lines should then preferably run in parallel.
• Wave crests / troughs that when assembling the heat exchanger network, the same can be pressed flat by means of a very small force that does not deform the tubes and the ribs.
• the heat exchanger should have corrugated fins that at least the features of
• Claim 1 have.
• the sheet thickness of the corrugated fins is between 0.02 and 0.09 mm.
• the wall thickness of the flat tubes can be between 0.05 and 0.15 mm, also slightly more.
• Test stage can be significant.
• Fig. 1 shows a piece of a proposed corrugated fin.
• Fig. 2 shows an enlarged section thereof.
• Fig. 3 shows an embodiment with dilution lines having interruptions.
• Fig. 4 shows an embodiment with cuts in the bending edges.
• FIG. 5 shows a development of FIG. 4.
• FIGS. 6 and 7 show a dilution line instead of the cuts.
• Fig. 8 shows an embodiment of the still internal prior art.
• Fig. 9 shows a part of a heat exchanger.
• Each wave crest 2 and each wave crest 3 has two bending edges 10, at the points where the wave crests 2 and the wave troughs 3 merge into the wave flanks 1.
• the wave crests 2 and the wave troughs 3 are substantially flat.
• the adjoining wave flanks 1 are slightly inclined in the illustrated embodiments according to FIGS. 1, 2 and 8. However, they can also be approximately vertical, as shown in FIGS. 3-7 show.
• exposed cuts 5 are arranged from their planes, which are as long as possible, so they go up to the bending edges 10 directly.
• the bending edges 10 are designed to be weakened so that either the bending occurring in the bending springback is reduced, or that the wave crests / troughs 2, 3 are so soft that they give way in the composition of the heat exchanger network. Attention is drawn in particular to FIG. 2, which shows a clearly enlarged illustration in the region of a wave crest 2 or a wave trough 3.
• FIGS. 1 and 2 belong to an exemplary embodiment in which it has been provided to form thinning lines 15 (bending notches) in the two bending edges 10 and also in the wave trough 2 or wave crest 3 between the two bending edges 10 (relief notches). Thereby, the mentioned softness is created, which should be shown in Fig. 2 with dH between two horizontal auxiliary lines.
• the reference numeral dH indicates the range by which each corrugation 2 and each corrugation 3 is as it were yielding in the assembly of flat tubes and corrugated fins and is substantially flat, can rest against the flat tube to perfect, even larger, solder joints between corrugated fins and to allow pipes.
• the wave crest / wave trough 2, 3 according to FIG. 2 is approximately at the level of the lower auxiliary line. It is also well understood from this illustration that then the distance between the lying at the level of the lower auxiliary line pipe wall to the beginning of the cuts 5 is to be shortened, which is reflected in an improvement in heat exchange. As a result, the height H of the corrugated fin is shortened, which has been drawn in FIG.
• the thinning lines 15 in the bending edges 10 are formed as bending notches, which may differ from the other notches (relief notches).
• the Bending notches and the relief notches can therefore be configured differently in, for example, depth and shape in order to realize the described intended effects even better.
• the cuts 5 are known to be introduced in the longitudinal direction of the sheet metal strip, which are issued thereafter.
• the proposed dilution lines 15 are also formed by means of the rollers.
• incisions 20 instead of the dilution lines 15, incisions 20 have been made, which should then likewise run in the transverse direction of the sheet-metal strip.
• FIG. 3 shows, in contrast to FIGS. 1 and 2, that it is possible to interrupt the dilution lines 15. There are spaced interrupts 16 available. Such designs ensure a little more stability.
• the dilution lines 15 lying in the bending edges 10 are replaced by notches 20.
• the cuts 20, which need not be cutouts but only slots, are in turn interrupted by webs 21.
• the incision length and also the web length can be set individually, as a comparison of FIG. 4 with FIG. 5 shows.
• the edges of the incisions 20 are issued something, as the figures can also show.
• FIGS. 6 and 7 show exemplary embodiments according to FIGS. 6 and 7, where a continuous or an intermittent dilution line 15 (bending notch) was provided in the bending edges 10.
• the further dilution lines 15 (relief notches) running in the wave crests / troughs 2, 3 were omitted here-in contrast to FIGS. 1 and 2.
• Fig. 8 shows an embodiment of the currently still internal state of the art. It is easy to imagine that here, for example, a dilution line 15 could be provided in the bending edges 10. Otherwise, in this embodiment, over the bending edges 10 running pairs of incisions 30 are provided.
• the portion 40 which is in each case between a pair of incisions 30, was deformed inwards in order to reduce the bypass in the area of the wave crests / troughs 2, 3. Since the stability of the corrugated ribs decreases due to the proposed measures, in particular their inclination to buckling could increase, it is also proposed here to provide the corrugations of the corrugated rib with a slight inclination or inclined position to the tube longitudinal direction, which is apparent from the illustration according to FIG should emerge. Normally, the corrugations run vertically (without inclination) to the tube longitudinal axis. The force that causes the buckling of the corrugated ribs also runs in the tube longitudinal direction.
• FIG. 9 shows one of the collecting tanks SK of the heat exchanger and a flat side of the heat exchanger tube, on which the proposed corrugated fins are located.
• the corrugated rib is shown as a section through the flanks 1, in which the exposed sections 5 are located.
• the oblique course should clarify the mentioned inclination of the corrugations or flanks 1 to the pipe axis.
• "oblique" corrugated fins also have advantages in terms of heat exchange between the corrugated fins and the pipes is a metallic compound, such as a solder joint exists (not shown) flows through the pipes, for example, the cooling liquid of an automotive engine and through the corrugated fins Cooling air flows, which was indicated by the conspicuous block arrow.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Geometry (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (1)

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Citations (6)

Family Cites Families (4)

• 2006
  • 2006-07-29 DE DE102006035209A patent/DE102006035209A1/de not_active Withdrawn
• 2007
  • 2007-07-27 WO PCT/EP2007/006655 patent/WO2008014929A1/de active Application Filing
  • 2007-07-27 EP EP07786369A patent/EP2049860B1/de active Active
  • 2007-07-27 DE DE502007005153T patent/DE502007005153D1/de active Active

Patent Citations (6)

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