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
  • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
  • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
  • F28F21/081—Heat exchange elements made from metals or metal alloys
  • F28F21/084—Heat exchange elements made from metals or metal alloys from aluminium or aluminium alloys
• • 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
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
• • 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
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/04—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being spirally coiled
• • 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
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/08—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being otherwise bent, e.g. in a serpentine or zig-zag
• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F7/00—Elements not covered by group F28F1/00, F28F3/00 or F28F5/00
  • F28F7/02—Blocks traversed by passages for heat-exchange media
• • 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
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
  • F28D2021/0054—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for nuclear applications
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F2215/00—Fins
  • F28F2215/10—Secondary fins, e.g. projections or recesses on main fins

Definitions

• the invention relates to a heat exchanger system with at least one heat exchanger, which consists of at least one tube carrying a first heat transfer medium, which is bent so that adjacent sections are connected to form a dense wall.
• the tube is cast with a metal to form the dense wall and that the wall on at least one side, which is coated by a second medium involved in the heat transfer, has heat-conducting projections, e.g. B. ribs.
• This design provides the additional advantage that the pipe material is protected from corrosion attacks by the cast jacket.
• the heat exchanger system is to have the shape of a cuboid, this is best achieved by the tube of each heat exchanger running in a single plane in a serpentine or meandering manner. If the supply and discharge lines form circular or annular connection cross sections, it is expedient to design the heat exchanger in such a way that the pipe or the pipes run along helical lines on a single, fictitious pipe cylinder. Such an arrangement also has particular advantages if the second medium has a pressure which is very different from the atmospheric pressure, in that the pipe coil is formed with its cast jacket to the load-bearing wall.
• the projections are designed as radially projecting ribs which run essentially in the axial direction of the tubular cylinder, because of this way the overall pressure drop can be kept relatively small. Another advantage of this arrangement is that it is simple to manufacture. If, on the other hand, the mass flow of the second medium is relatively small and you can, e.g. B. for pollution reasons, the flow cross-sections for the second medium not arbitrarily, it is advantageous that the projections are designed as radially protruding ribs which run essentially along helical lines.
• the ribs in the case of pipes wound according to helical lines can preferably be designed in such a way that the turns of the pipes increase in the opposite sense to that of the ribs.
• a considerable improvement in the heat transfer on the side of the second medium can be achieved in that the rib cross section branches out like a tree.
• the ribs are advantageously divided in their length. It is advisable to provide a parting line of approximately the rib thickness.
• a significant improvement in the heat transfer can then be achieved in that one of the trailing edges of the ribs is sharpened on one side.
• the boundary layer is guided from one side of the narrow flow channel between the ribs to the other side of the ribs, so that new boundary layers are formed at each parting line.
• the material used to cast the pipes is made of at least 50% aluminum.
• Manufacturing advantages arise from the fact that the tube or tubes consists of steel or another metal that melts at a higher temperature than the melting temperature of the potting metal.
• the pipe or pipes thus not only form a "lost formwork", but they also ensure a better controllable surface quality in the flow area of the first medium.
• the capacity of a heat exchanger is increased moderately achieved in that it is adjacent to at least a second heat exchanger of the same type, the heat exchangers at least almost touching each other, and wherein, with a circular cylindrical design of the heat exchangers, they are arranged concentrically to one another.
• the heat exchangers are particularly easy to manufacture if the tubes are first bent and placed in a casting mold, this mold is then poured out and then the projections are machined out of the casting material.
• this mold is then poured out and then the projections are machined out of the casting material.
• Thermal stresses in the structure of the heat exchangers can be significantly reduced by using tube material that has a melting temperature that does not differ greatly from the melting temperature of the casting material, the tube or tubes being filled with a filler, preferably sand, during the casting process.
• the heat capacity of the filler prevents the pipes from melting continuously. It also prevents an on bulge under the effect of the pressure of the melt. If the heat exchanger is built in large numbers, it can be advantageous if the pipe material has a melting temperature that does not differ greatly from the melting temperature of the casting material, if the pipe or the pipes are cooled inside - preferably by a flowing auxiliary medium - during the casting process .
• heat exchangers can be combined to form a cuboid system in that the outermost fins of adjacent heat exchangers are tightly connected to one another, preferably welded together, to form a closed channel that guides the second medium.
• Fig. 1 shows a longitudinal section through a box with several, flat heat exchangers.
• Fig. 2 shows a cross section II - II through the box of FIG. 1.
• 3 is a cross section through two concentrically arranged, circular cylindrical heat exchangers.
• FIG. 4 shows, on an enlarged scale, a longitudinal section IV-IV of the heat exchangers according to FIG. 3.
• FIG. 5 shows, analogously to FIG. 3, a cross section through two concentrically arranged heat exchangers, of which the inner has ribs on both sides.
• FIG. 6 shows a longitudinal section of a variant of FIG. 5.
• Fig. 7 shows a longitudinal section through a system of several Heat exchangers, in each of which a tube is arranged after a spiral.
• Fig. 8 is a horizontal section through the height levels VIIIi, VIII2 and VIII3 through one of the heat exchanger according to FIG. 7.
• Fig. 9 illustrates the cross section through two ribs with branches.
• Fig. 10 shows the cross section of another embodiment of branched ribs and their mutual arrangement.
• 11 and 12 represent cross sections through further ramified ribs, which are made of sheet metal strips.
• FIG. 13 shows a fragmentary cross section through a circular cylindrical heat exchanger with simple ribs that run along helical lines.
• each of the heat transfers consists of a tube 3, which is bent back and forth in a vertical plane.
• the tubes 3 are each cast with an aluminum body 4, the ribs 5 of which have cast-in side faces parallel to the plane of the associated tube.
• the outermost fins 5 ' are somewhat longer than the other fins and are each connected by a weld 6 to an abutting fin 5' of an adjacent heat exchanger 1, so that the aforementioned box shape is created.
• an end plate 8 welded, which extends over the entire outer fin surface of this heat exchanger.
• each end plate 8 there is a funnel wall 9 and two funnel surfaces 10 and 11 are welded to the upper transverse edges of the heat exchangers formed by the connected ribs 5 '.
• a discharge line is connected to this funnel, which cannot be seen from the drawing.
• An identical funnel with a feed line for the second medium is located at the lower end.
• the pipes 3 emerge laterally from the box 2 at the top and bottom and end at flanges 13.
• the flanges 13 are connected to flanges of pipe sockets 14, which open into a manifold at the top and into a distributor 15 and below, not shown in the drawing.
• These distributors and collectors are divided by bellows 17, taking into account the thermal expansion differences of the collector or distributor on the one hand and the aluminum body on the other hand.
• the spaces between the end plates 8 and the heat exchangers 1 adjacent to them and the spaces between adjacent heat exchangers 1 are flowed through from below by a heat-emitting gas.
• the large heat transfer area of the fins 5 compensates for the relatively poor heat transfer coefficient of the gas, so that the temperature difference between the heat-emitting gas and the heat-absorbing surface of the fins 5 remains relatively small.
• the fins 5 are designed to be tightened so that the increased heat flow in the region of the fin foot can flow to the pipe 3 with a relatively low temperature drop. Since the water flowing in the pipe 3 ensures good heat transfer, there are also no high temperature differences on the water side.
• tubes 3a and 3b are wound according to helical lines.
• Each tube coil formed in this way is encased by an aluminum body 4a or 4b, each forming a circular cylindrical heat exchanger la and lb.
• the heat exchanger la has on its inside radial longitudinal ribs 5, while the cylindrical outside is smooth.
• a greatly widened fin 23 is provided, in which a piece of pipe 24 connected to the upper end of the coiled tubing runs axially parallel downwards. Below the heat exchanger, the pipe section 24 leads outwards through a funnel wall (not shown).
• a gas flows through the strongly fissured annular space delimited by the surfaces of the ribs 5, while a liquid flows through the two tubes 3a and 3b, which are preferably connected in parallel.
• ribs are also arranged on the inside of the heat exchanger 4b.
• the flow channel of the gas is delimited on the inside by a circular-cylindrical displacer 25.
• the outer heat exchanger 4a could also be provided with outer ribs and surrounded by a circular-cylindrical jacket.
• the exemplary embodiment according to FIG. 6 differs from that according to FIG. 5 in that the inner heat exchanger 4b has two tube coils 3c and 3d, both of which open at their upper end into a common collector tube 26 which is surrounded by an aluminum jacket 27 leads the wall of a funnel 28 and finally ends outdoors with a flange 29.
• the upper end of the tube coil 3a leaves the heat exchanger 4a outside the funnel 28. Its end is provided with a flange 29 '.
• five heat exchangers 4f ... 4k are designed as annular disks and are arranged coaxially one above the other. Inside the heat exchangers 4f ... 4k, the pipes 3f ... 3k are bent according to spirals.
• the ribs are perpendicular to the plane of the tubes 3 and are bent according to involutes.
• the heat exchangers 4f ... 4k are surrounded on the outside by a cylindrical jacket which is tightly connected to the heat exchangers 4f, 4h and 4k by means of flat annular plates 31, 32 and 33.
• Two shut-off disks 35 and 36 are arranged on the inside of the heat exchangers in the bore of the heat exchangers 4g and 4i.
• the involute ribs if you follow them in the opposite direction, lead on the top of the disc (section VIII 1 ) from the outside inwards and on the underside from the inside to the outside.
• the uppermost heat exchanger 4f only has fins on its underside, which run like those on the top of the adjacent pane 4g.
• the heat exchanger 4i is designed in the same way as 4g, while the heat exchanger 4h in between has ribs that run in reverse: on the top, always referring to the counterclockwise direction, they lead from the inside to the outside and on the bottom from the outside to the inside.
• the bottom heat exchanger 4k only has fins on its top, which run from the inside to the outside.
• This rib arrangement ensures that the gaseous medium, which enters the stack of heat exchangers centrally from below through the inlet 50, flows outward in the counterclockwise direction between the mutually facing ribs 5 of the heat exchangers 4i and 4k, through the lower annular space 42 between the Heat exchanger 4i and the jacket 30, rotating further in the counterclockwise direction, rises and flows inward in the counterclockwise direction through the spaces between the heat exchangers 4h and 4i. Continuously rotating in the same direction, it flows outward between the heat exchangers 4g and 4h into the upper annular space 42 'and finally, flowing inward between the heat exchangers 4f and 4g, arrives at the outlet opening 51 of the heat exchanger system.
• Each of the pipes 3g ... 3i initially extends radially to the associated disk of the heat exchanger.
• the radial section 38 located within the jacket 30 is encapsulated with aluminum.
• Each tube 3g ... 3i runs in the disk as a spiral 40, preferably wound as an involute with a small radial pitch, up to the inside edge of the disk.
• each of the tubes 3g ... 3i in each case passes into the level of the fins on the underside of the heat exchanger in question, where it is embedded as an involute tube 41 in a thickened fin 23 'which, like the neighboring fins, extends in an involute manner.
• each involute tube 41 merges into a radial tube section 43 which penetrates the jacket 30 and is encased with aluminum within the jacket.
• the pipes 3f and 3k also have radial pipe sections 39, which are however located outside the annular spaces 42 and 42 'and merge into spiral pipes in the disk 4f and 4k.
• the spiral tubes are led out of the disk upwards and downwards and continue as tubes 44 and 45, respectively.
• the changes in direction of the tube are chosen to be as small as possible by the water circulating within a heat exchanger in the spiral tube 40 as well as in the involute tube 41 in the same sense.
• the spiral tube 40 of the heat exchangers 4g and 4i is wound from the outside inwards in the counterclockwise direction, while that of the heat exchangers 4h and 4k runs clockwise from the outside inwards.
• the pipes 3f ... 3k are expediently connected in series, according to the countercurrent principle, which, however, cannot be implemented consistently here.
• the pipe section 39 of the heat exchanger 4f is therefore connected to the involute pipe 41 of the heat exchanger 4g, the involute pipe 44 forming the water inlet.
• the pipe section 38 of the heat exchanger 4g is connected to the section 38 of the heat exchanger 4h, the involute pipe of which is connected to the section 38 of the heat exchanger 4i and finally the involute pipe of the heat exchanger 4i is connected to the section 39 of the heat exchanger 4k.
• Practical. Considerations as well as thermodynamic calculations can also lead to a different circuit.
• Ribs according to Fig. 10 are easy to cast, while the extrusion presents difficulties due to the uneven cross-sectional distribution.
• the cross-sectional shapes according to FIGS. 11 and 12, which are assembled by soldering simple angle profiles 60, are more favorable. These can be formed by folding sheet metal or by extrusion.
• the profiles 60 are preferably joined together with a first, high-melting solder to form a branched rib, which is then soldered into the grooves 56 of the heat exchanger 55 with a second, less high-melting solder.
• ribs 61 radia extend inwards from a circular cylindrical heat exchanger 60, the ribs running along helical lines. This arrangement makes the flow path longer and at the same time the flow cross section smaller, which can help to optimize the heat transfer.
• FIG. 14 shows the development of a heat exchanger with inclined, divided ribs.
• One (70) of the trailing edges 70, 71 of the ribs is rounded off with a large radius.
• the Coanda effect causes a thin layer of the medium flowing between the ribs to pass through the gap between each other. following ribs in the next flow path. This phenomenon can further improve the heat transfer.
• the ribs shown inclined in FIG. 14 can also run in the axial direction, in which case the interruptions between the ribs can follow a helix.
• FIG. 14 can also be applied to the flat heat exchanger according to FIG. 1.

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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)

Family

ID=4241865

Family Applications (1)

Country Status (7)

Cited By (7)

Families Citing this family (5)

Citations (15)

Family Cites Families (2)

• 1978
  • 1978-03-15 CH CH280078A patent/CH625611A5/de not_active IP Right Cessation
• 1979
  • 1979-03-14 ZA ZA791190A patent/ZA791190B/xx unknown
  • 1979-03-14 DE DE7979900267T patent/DE2963708D1/de not_active Expired
  • 1979-03-14 JP JP50050079A patent/JPS55500151A/ja active Pending
  • 1979-03-14 WO PCT/CH1979/000040 patent/WO1979000766A1/de unknown
  • 1979-03-14 AU AU45112/79A patent/AU526929B2/en not_active Ceased
  • 1979-10-12 EP EP79900267A patent/EP0015915B1/de not_active Expired

Patent Citations (15)

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