Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K1/00—Soldering, e.g. brazing, or unsoldering
  • B23K1/0008—Soldering, e.g. brazing, or unsoldering specially adapted for particular articles or work
  • B23K1/0012—Brazing heat exchangers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
  • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
  • B23P15/26—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass heat exchangers or the like
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K1/00—Soldering, e.g. brazing, or unsoldering
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K1/00—Soldering, e.g. brazing, or unsoldering
  • B23K1/20—Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K1/00—Soldering, e.g. brazing, or unsoldering
  • B23K1/20—Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating
  • B23K1/203—Fluxing, i.e. applying flux onto surfaces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
  • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
  • F28D1/03—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
  • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
  • F28D1/03—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits
  • F28D1/0391—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with plate-like or laminated conduits a single plate being bent to form one or more conduits
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
  • F28F13/06—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media
  • F28F13/12—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media by creating turbulence, e.g. by stirring, by increasing the force of circulation
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/04—Tubular or hollow articles
  • B23K2101/06—Tubes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/04—Tubular or hollow articles
  • B23K2101/14—Heat exchangers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/34—Coated articles, e.g. plated or painted; Surface treated articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/08—Non-ferrous metals or alloys
  • B23K2103/10—Aluminium or alloys thereof
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/4935—Heat exchanger or boiler making
  • Y10T29/49377—Tube with heat transfer means
  • Y10T29/49378—Finned tube
  • Y10T29/49384—Internally finned

Definitions

• the invention relates to a brazing process for a heat exchanger, particularly for motor vehicles, a tube and a heat exchanger thus obtained.
• the invention relates to the field of heat exchangers, especially for motor vehicles.
• the heat exchangers conventionally comprise a bundle of tubes and two collector plates traversed by the ends of the tubes of the bundle of tubes and capped by covers of fluid distribution boxes. Interlayers may also be provided between the tubes of said bundle to improve heat exchange.
• the brazing is carried out with a supply of brazing, most often made in the form of a veneer.
• the tubes used in the brazed heat exchangers are made of a low oxidation metal material, such as aluminum or an aluminum alloy.
• Brazed heat exchangers are known whose bundle tubes are extruded so as to define a plurality of circulation channels for the flow of the fluid.
• this solution can be relatively expensive.
• interlayers or disturbance fins are arranged inside the tubes of the heat exchanger bundle to increase the heat exchange surface and thus improve the performance of the heat exchanger .
• the object of the invention is to overcome these drawbacks of the prior art by guaranteeing proper brazing of the surfaces inside the heat exchanger tubes at a lower cost.
• the subject of the invention is a brazing process for a heat exchanger between at least a first and a second fluid, said exchanger comprising a bundle of tubes for the flow of said first fluid, characterized in that it comprises the steps following:
• a metal strip is folded so as to form at least one tube
• a perturbation spacer of thickness substantially less than or equal to 150 ⁇ is arranged inside said tube, and
• said metal strip and / or said interlayer comprises a plating layer on at least one surface to be brazed so that the ratio of the volume of the plating layer to the volume to be brazed is substantially greater than or equal to a predetermined threshold as a function of the mean distance between said spacer and said tube, and
• the method may further comprise one or more of the following features, taken separately or in combination:
• said threshold is substantially of the order of 1.5 for an average difference of the order 0.05 mm between a tube and a spacer;
• said threshold is substantially of the order of 1.75 for an average difference of the order of 0.05 mm between a tube and a spacer;
• said interlayer comprises a plating layer
• the inner surface of said tube comprises a plating layer; said method comprises the following steps:
• a plurality of tubes comprising a plating layer on at least one surface to be brazed outside said tubes are prepared;
• a plurality of tubes are stacked by interposing flow interferers of said second fluid between said tubes, and
• a plating layer is disposed on the outer surface of said tubes;
• the invention also relates to a heat exchanger tube formed by folding a metal strip, characterized in that it is brazed according to a soldering method as defined above.
• said metal strip comprises aluminum.
• the invention also relates to a heat exchanger, in particular for a motor vehicle, comprising a bundle of tubes, characterized in that it is brazed according to a soldering method as defined above.
• FIG. 1 partially and schematically represents a heat exchanger
• FIG. 2 is a cross-sectional view of a tube of the exchanger of FIG. 1, and
• FIG. 3 schematically illustrates a metal strip serving for forming the tube of FIG. 2.
• the invention relates to a method of brazing tubes 1 suitable for use in brazed heat exchangers.
• a heat exchanger is air conditioning condensers for motor vehicles.
• the heat exchange is between a first fluid such as a refrigerant, and a second cooling fluid such as glycol water.
• a heat exchanger 3 conventionally comprises a plurality of longitudinal tubes 1 mounted between two distribution boxes in which a first fluid circulates, via collecting plates 5 (represented partially and schematically) deposited transversely relative to the tubes 1 and having orifices (not shown) for receiving the ends of these tubes 1.
• Interlayers or disruption fins 7 are disposed inside the tubes 1 so as to disturb the flow of the first fluid in the tubes 1 by increasing the exchange surface.
• These spacers 7 are for example brazed to the tubes 1 at the vertices 7a of their corrugations and for example at the ends 7b of the spacers 7.
• spacers 7 are made thin, that is to say substantially less than 150 ⁇ , to reduce costs. According to a preferred embodiment, the spacers 7 have a thickness of the order of 100 ⁇ .
• spacers 7 are well known to those skilled in the art and are not described in more detail herein.
• the tubes 1 can be separated from each other by disruptors 9 (FIG. 1), for example corrugated, traversed by the second fluid for a heat exchange with the first fluid.
• disruptors 9 are in the illustrated example arranged transversely to the longitudinal axis of the tubes 1.
• Figure 2 shows a sectional view of a tube 1 of such exchanger 3.
• the tube 1 is made from a metal strip 11 folded and brazed. This is called "folded tube”.
• This metal strip 11 ( Figure 3) is preferably aluminum or aluminum alloy.
• the metal strip 11 is for example of generally rectangular shape and comprises a first face called outer face 13 and a second face said inner face 15 parallel to the outer face 13 and opposite thereto.
• the terms "internal” and “external” are defined with respect to the inside and outside of the folded tube 1.
• the metal strip 11 forming the tube is provided with a plating layer on at least one surface to be brazed. In other words, there is provided a metal strip 11 having a plating layer at least disposed at the areas to be brazed.
• One embodiment proposes that the surface to be brazed is intended to be located inside said tube once it is assembled.
• the tube 1 formed has a substantially "B" cross section.
• other sections may be provided.
• the cross-section at "B" of the tube 1 illustrated has two parallel fluid circulation channels juxtaposed 17a and 17b and separated by a partition 19 forming a spacer.
• the metal strip 11 is folded so as to form the envelope of the two parallel channels juxtaposed 17a and 17b. More specifically, the metal strip 11 is folded so that its inner face 15 delimits the two channels 17a, 17b.
• the partition 19 is for example made by folding substantially 90 ° two opposite edges 11a and 11b of the metal strip 11, for example the longitudinal edges of the strip 11. Then, these edges 11a, 11b folded back against one against the other to jointly form the partition 19.
• the outer face 13 at the edge 11a is therefore opposite the outer face 13 at the opposite edge 11b.
• the outer face 13 of the band 11 forms the outer surface 21 of the tube 1 thus formed, and the inner face 15 of the band 11 forms the inner surface 23 of the tube 1 thus formed.
• the outer surface 21 of the folded tube 1 has two large outer faces 21a, 21b opposite and which are connected by two small side faces 21c and 21d, for example substantially curved.
• the tubes 1 obtained can then be assembled with the spacers 7 and corrugated disruptors 9, to form a beam that can be brazed.
• the tubes 1 are formed by folding a metal strip 11;
• the spacers 7 are arranged inside the tubes 1;
• the tubes 1 are engaged in associated orifices of the collector plates 5, on which are mounted the end distribution boxes of the heat exchanger;
• disrupters 9 can be mounted between the stacked tubes 1;
• the brazing is carried out conventionally with the use of a solder and in order to improve the brazing process it is also possible to use a brazing flux, for example applied in the form of a paste under controlled conditions, which dissolves the solder. oxide layer formed naturally on the surface of the parts to be assembled and wetting the parts to be soldered to thereby allow the solder to spread on the contact surfaces.
• a brazing flux for example applied in the form of a paste under controlled conditions, which dissolves the solder. oxide layer formed naturally on the surface of the parts to be assembled and wetting the parts to be soldered to thereby allow the solder to spread on the contact surfaces.
• Brazing is most often formed of a layer of veneer.
• the filler metal has a lower melting temperature than the metal forming the core of the tube 1, for example aluminum.
• the plating layer is placed directly on the metal strip 11 used for the manufacture of the tube.
• the configuration that there is no cladding layer on the outer surfaces 21 of the tubes 1 therefore requires disruptors 9 plated, resulting in additional cost. Accordingly, the plating layer is preferentially disposed on the outer surface 21 of each tube 21.
• the veneer layer may be disposed only on the brazing surfaces of the spacers 7 or alternatively both on the spacers 7 and on the inner surface 23 of each tube 1.
• the tabs 7 plated have a greater thickness, which increases the cost. Accordingly, the plating layer is preferably also disposed on the inner surface 23 of each tube 1.
• the thickness of the plating layer is standardized. Indeed, the limit of the thickness of the plating layer on the spacers 7 is of the order of 10 to 15% of the material thickness of the interlayer. Similarly, the thickness of the plating layer on the inner surface 23 of the tube 1 is defined by a standard and the limit is of the order of 12.5 to 15% of the material thickness of the tube 1.
• the ratio is insufficient and therefore less than a predetermined threshold, the amount of plating will be insufficient compared to the area to be brazed to ensure brazing of all the folds of the spacer 7 on the inner surface 23 of the tube 1.
• the total length to be brazed is defined and multiplied by the average distance between the inner surface 23 of the tube 1 and the surface to be brazed of the insert. average deviation is for example of the order of
• the BCR ratio greater than or equal to a threshold of 1.75 for an average deviation of 0.05 between a tube 1 and a spacer 7, makes it possible to guarantee correct brazing of the folds of the insert 7 on the inner surface 23 of the tube 1, for spacers 7 of relatively low thickness, for example less than 150 ⁇ or even of the order of 100 ⁇ , as previously mentioned.
• the soldering method provides that a plating layer is disposed on the insert 7 at the vertices 7a and possibly the ends 7b, and / or on the inner surface 23 of the tube 1, making sure that the ratio BCR of the volume of the plating layer on the volume to be soldered is greater than the predetermined threshold as a function of the average deviation between the tube 1 and the vertices 7a.
• the volume of plating used for brazing can be determined from the residual amount of plating inside the tubes 1 and the amount of plating present at the joints between the plating. insert 7 and the inner surface 23 of a tube 1.
• a low-cost heat exchanger 3 which has so-called folded tubes 1 and whose perturbation fins 7 are relatively thin, while ensuring contact between all the folds of the disturbance fins 7 on the internal surfaces. 23 of the tubes 1.

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=44486115

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (10)

• 2010
  • 2010-12-20 FR FR1060802A patent/FR2969018B1/fr not_active Expired - Fee Related
• 2011
  • 2011-12-13 CN CN201180067999.6A patent/CN103702791A/zh active Pending
  • 2011-12-13 JP JP2013545178A patent/JP2014501621A/ja active Pending
  • 2011-12-13 WO PCT/EP2011/072516 patent/WO2012084584A1/fr active Application Filing
  • 2011-12-13 EP EP11805448.5A patent/EP2655000A1/fr not_active Withdrawn
  • 2011-12-13 US US13/995,825 patent/US20140158331A1/en not_active Abandoned

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