FR2472157A1 - HEAT EXCHANGER WITH FLAT TUBES - Google Patents

Abstract

THE INVENTION RELATES TO A FLAT TUBE HEAT EXCHANGER. FOR THE MANUFACTURE OF A CURVED DRAINAGE PATH, 11 PACKS OF STRAIGHT FLAT TUBES 21 ARE USED, THE END WALLS, TURNED TO ONE ANOTHER, EACH TIME TWO 11 PACKS 11 OF FLAT TUBES 21, ARE ASSEMBLED WITH TWO OPENINGS 22 OF A COLLECTOR CHAMBER IN THE FORM OF ANGULAR BOX 12, SO THAT THE DIRECTION OF FLOW OF THE MIDDLE SUBJECTS THE SIZE OF ANGLE 15 OF THE CORNER BOX. THE INVENTION APPLIES TO HEAT EXCHANGERS, IN PARTICULAR TO CHILLERS.

Description

The invention relates to a heat exchanger comprising at least one package

  of flat tubes which consists of flat tubes of equal length, provided for the flow of a first medium, which are mounted together so that their wide sides overlap forming intermediate spaces for

  the flow of a second medium, and whose ex-

  adjacent tremities are connected to an end wall which closes an opening of a collector box on the outside, through which the flat tubes open into a chamber

  collector collector, in particular

  of an oil cooler where the first medium flowing through the flat tubes is

  the oil and o the second medium is air.

  We know a heat exchanger of this kind

  according to the German patent application

  vis-à-vis DE-AS 21 13 583. The use of flat tubes in the heat exchangers not only has the advantage that this gives a relatively high efficiency of the heat exchange, but that heat exchangers heat of this kind still have

  advantages from the point of view of manufacturing.

  Thus it is possible to form a bundle of flat tubes from rectangular plates which are connected, for example welded, alternately to different opposite edges, by strips which close towards the outside the spaces lying

  between the plates, so that

  paces of flow which extend in

  tions differing from each other by 90 degrees. As we know, it is possible to very simply manufacture such bundles of tubes by stacking

  rectangular plates and corresponding strips

  soldering plates, one above the other to form a package that is then introduced into an oven where the elements are welded together.

to each other.

  Also, packages of flat tubes in which the flat tubes are formed of welded tubes

  or round tubes without seams, flattened by com-

  pressure, for example have particular advantages when building heat exchangers

  corrosion proof. In such a case, the

  for example, dishes may be made of special steel. In all known heat exchangers, in which welded flat tubes are used or

  without seams, the flow spaces for the first

  first middle through the flat tube extend in rectilinear direction. In practice, however,

  there may be circumstances in the-

  which the first medium must be driven along a curved path. Since these flat tubes can not be bent around an axis perpendicular to their flattening, in such a case flat tubes could only be used when they were made from arcuate plates with curved strips. bow shape. Such arc-shaped plates, however, lead to a

great loss of material.

  The object of the invention is to provide a flat tube heat exchanger in which a curved flow path for the first

  medium is possible, also with flat tubes rec-

  tilignes. According to the invention, this problem is solved by a heat exchanger of the aforementioned type, by

  the fact that the collector box has two

  vertures for the assembly each time a wall.

  end, each time a pack of flat tubes, and in that the surfaces defined by these two openings form an angle between them, so that the collector box forms an angular box which assembles two packs of flat tubes so such as the flow directions of the flat tubes

  both bundles of flat tubes extend into

  this angle between them. We thus obtain that by means of an angular box, we can gather one

  to the other two packs of flat tubes forming an

  with each other and so that we can deviate

  the flow of the first medium despite the pre-

the presence of rectilinear flat tubes.

  The invention can be developed in a

  particularly advantageous by giving the angle between the two opening surfaces of the angular box a value of 1 / n of 360 degrees and by assembling

  n packages of equal flat tubes using n cais-

  such angular sounds, to form an exchange of

  Annular heat source with n sides. The invention thus gives the surprising possibility of manufacturing from packages of flat tubes consisting of

  rectilinear tubes, an annular cooler.

  As a matter of fact, according to German Published Application No. 2200826, a cooler is known

  annular flat tube. This one is formed all-

  times of cut plates in the form of rings, which are connected by shaped elbows

  of rings to form flat tubes for the first

  M in the middle, and which are interconnected by sheets of sheet metal folded in the form of rings, for the formation of flow spaces, directed

  radially, for the second medium. In the manufacture

  cation of the annular plates and lamellae for this annular heat exchanger, a lot of material is lost in the cutting of the ring-shaped plates. By cons, with the invention, we obtain that the flat tubes for a ring cooler

  can be made from rectangular plates

  connected to each other by means of rectangular strips. Cutting plates and strips is possible then virtually without losses. Another advantage of this configuration according to the invention lies in the fact that, for an annular cooler, it is also possible to form

  packages of flat tubes from

  dice or round tubes without seams, flattened by

  compression, which can be very advantageous,

  especially in cases of particular assemblies, when it is necessary to manufacture the round cooler in a material resistant to corrosion, for example

made of special steel.

  For feeding and starting the first medium in the flat tubes forming a tower, a round heat exchanger according to the invention can be provided with two angular boxes each time an inlet pipe and a starting pipe for the first medium, these tubes being arranged preferably

  at diametrically opposite points.

  In a preferred embodiment,

  a, in at least one angular box, associated with each

  one of the two openings a collecting chamber, the two collecting chambers being separated from each other by an inner partition and each being provided with a connecting pipe for the first medium. We thus obtain that it is possible

  to conform a ring heat exchanger

  the invention so that the first medium is introduced into one of the collector chambers of the angular well and then flows through all the flat tubes of the annular heat exchanger to the other collector chamber of the same well. angular where it is then evacuated by the starting tubing. But it is also possible to use two or more of these subdivided angular boxes, so that two or more flow spaces will be obtained for two or more different first media. It is thus possible, with a single annular heat exchanger, and for example with a single second medium (for example air), to cool several first different media. Another advantage of the invention is that, by the only different conformation of the

  angular boxes, in particular by the choice of different

  fractions of 360 degrees for the angle

  be the two opening surfaces, we can, at

  from packages of identical flat tubes, consis-

  tracing ring-shaped heat exchangers

  polygonal towers and so with a dia-

  relatively large ring, which simplifies

  also manufactures coolers for

different sizes.

  The following invention will be described in exemplary embodiments shown in the drawings. In these drawings: FIG. 1 is a perspective view of a first exemplary embodiment of a heat exchanger which comprises only two packages of flat tubes consisting of seamless tubes, flattened by compression;

  FIG. 2 is a side elevational view

  a pack of flat tubes of the heat exchanger of Figure 1; FIG. 3 is a perspective view of the angular box employed in the exemplary embodiment according to FIGS. 1 and 2; FIG. 4 is a perspective view of a second embodiment of a heat exchanger comprising two packs of flat tubes; FIG. 5 is a plan view from above,

  partly in section and with tearing, of the sample

  heat generator according to Figure 4; FIG. 6 is a perspective view showing the structure of a flat tube package of the exemplary embodiment according to FIGS.

  Figures 4 and 5, in the exploded state; -

  FIG. 7 is a representation, analogous

  3, an angular box with two collecting chambers; FIGS. 8, 9, 10 and 11 are plan views of various annular heat exchangers

constructed according to the invention.

  The heat exchanger shown in FIG.

  re 1 consists of two packets of flat tubes de-

  11 as a whole, which are assembled by an angular box generally designated by 12. The angular box 12 which is shown

  only in perspective in Figure 3 shows two

  13 and 14 which each define an over-

  flat opening face. These opening surfaces form an angle between them (FIGS. 1 and 5) and are interconnected by the interior space of the

angular box.

  The flat-tube bundle 11 consists, in the exemplary embodiment of FIGS. 1 and 2, of rectilinear flat tubes of the same length, 21, which are formed by compression-flattening

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  seamless round tubes, which may be manufactured, for example for applications where corrosion is a hazard, of special steel

  or another metal not subject to corrosion. The former

  tremities flat tubes 21 of the same length are

  assembled (for example welded) on the edges of the

  22 in each case a plate 23, so that the plates 23 which are at both ends of the bundle of flat tubes 11 form end walls of the bundle of flat tubes. Each of the two openings 13 and 14 of the angular box 12 is closed by an end wall, formed of a plate 23, of a bundle of flat tubes 11, which can be obtained, for example, by welding the plate 23 at the edges of each opening 13 or 14. The wall

  free end can then be assem-

  another box or other collection box. By assembling the two packs of flat tubes by means of the angular box 12, a curved flow channel is provided for the first

  middle, despite the straight nature of the

these flow flat tubes.

  The exemplary embodiment shown in FIGS. 1 and 2 may also form part of an annular heat exchanger, that is to say in the form of a ring, as will be described in detail in the following and as FIGS. 1 and 2 may therefore also be considered as fractional representations of a part of such an annular heat exchanger. The particular advantage of such an annular heat exchanger constructed from packs of flat tubes 11 is that it can be manufactured from

  seamless bundles of tubes, flattened by compres-

  made of a corrosion-resistant metal,

  for example special steel or similar material

ford.

  The exemplary embodiment of an exchange

  of the heat shown in Figures 4 to 6 cor-

  responds to the heat exchanger of Figure 1, with the only difference here, each package

  of flat tubes 111 is formed of rectangular plates

  congruent layers 123 which are arranged one above the other in overlapping and which are kept at a distance from one another by means of

  strips 124 and 125 and assemblies (for example,

  dees) to these strips. The strips 124 are then

  arranged along the longitudinal edges of the

  rectangular panels 123, so that two plates

  123 next to each other and the sliders

  gitudinales 124 form each time a flat tube

  extending in the longitudinal direction of the

  rectangular tubes 123, this flat tube fulfilling the role of a flat tube 21 of the embodiment example according to Figure 1 and serving for the flow of a first medium, for example

  of oil in an oil cooler. The space

  intermediate formed by the distance between two flat tubes thus superimposed is limited laterally by two strips 125 which extend along the short edges, opposite each other, plates 123,

  and which are connected there to the plates 123 which

  pliquent. These strips 125 and the plates which are assembled to them limit flow spaces

  whose direction of flow extends perpendicular

  the flow direction of the flat tubes and used for the flow of a second medium, for example air, in an oil cooler. To improve the heat transfer between the second medium, through the plates 123

247,215?

  which limit these intermediate spaces, and the first

  The first medium flowing through the flat tubes has, in these flow spaces which extend along the strips 125, lamellae 126 which can be welded to the adjacent plates 123. manufacture such a package of flat tubes in a very simple and virtually waste-free manner by superposing (as shown in FIG. 6) the plates 123 and the strips 124 and 125. If the plates 123 and the strips 124 and 125 are soldered, a package thus formed will be introduced, in a manner known per se, into a furnace of

  welding or in a solder bath so that these parts

  are welded together in a watertight

a work pass.

  In a package of flat tubes 111 welded together in this manner, the end walls are formed by the small ribs of the plates 123, by the ends of the strips 124 and the outer wide sides of the strips 125. These end walls can be assembled, that is, welded together, with the edges of the openings 13

angular boxes 112.

  FIGS. 8 to 11 show various annular heat exchangers manufactured using

  of flat tube packages 11 or 111. In these samples,

  Ring heat generators: it is necessary, outside

  of an angular box 12, again an angular box

  112 (Figure 7) or 212 (Figure f). In the angular box 412, the interior space is divided

  by an inner partition 16 in two chambers col-

  17 and 18 to which are associated the

  13 and 14. Each of these chambers is

  these 17 and 18 is connected to a connecting pipe-

  19. The angular box 212 has, like the angular box 12, a continuous interior space and is connected, moreover, to a connecting pipe 19 '. Depending on the size of the angle 15

  formed between the two opening surfaces of the

  angular sounds 12, 112, 212 can be varied at

  will the number of sides of the heat exchanger

  their annular to several sides.

  In the exemplary embodiments of Figures 8 and 9, the angle indicated by 15 is 90 degrees. This produces a four-sided annular heat exchanger. In the exemplary embodiment according to FIG. 8, two

  angular boxes 112 each time with two cham-

  These angular boxes 112 are arranged at opposite corners to each other of the annular cooler. The other two angular boxes 12 each form a passage chamber

  unique.As shown in Figure 8 by arrows

  127 and 128, as well as the lines of

  129 and 130 drawn in dashed lines, this

  figuration provides two flow spaces for

  the first medium flowing in the flat tubes.

  Such an annular heat exchanger can be used

  folded for a current divided into two currents par-

  first half or for the first two months

different places.

  The annular heat exchanger shown in FIG. 9 is not distinguished from that of FIG.

  8 by the fact that here the two angular compartments

  In this case, the connection flanges 19 'with the connecting flanges 19' only constitute a single flow space therethrough and therefore have only one connecting flange 19 'each time. This gives an annular heat exchanger which

  can only be used for a single environment -

  flowing through the flat tubes, the flow of this medium being divided, as indicated also in FIG. 9 by arrows and dashed lines, into two branches which are brought together in a single section.

  in the connecting pipe 19 '.

  In the exemplary embodiment

  shown in Figure 10, we see a heat exchanger

  annular heat in which the opening surfaces

  The angular boxes 12 'and 112' form between them an angle of 3600/3 = 1200. By means of these angular boxes 12 'and 112', a three-sided annular heat exchanger can be constructed. In this exemplary embodiment, a

  only angular box 112 'is divided into two chambers

  collectors and is equipped with two

  19. The other two cubicles

  12 'have only one collecting chamber

  unique that functions as flow space.

  In this annular heat exchanger the first medium enters the annular heat exchanger

  by one of the connecting pipes 19, it par-

  runs the entire heat exchanger through

  The annular heat exchanger shown in FIG. 11 has two angular boxes 12 '' and three angular boxes 112 '' in which the flat tubes and then flows outwards through the second connecting tube 19. the angle 15 between the opening surfaces is 3600/5 = 720. Using these angular boxes, a five-sided heat exchanger can be constructed. The three corner boxes 112 '' employees

  here are divided each time into two chambers

  each time equipped with two tubes of

  19. This annular heat exchanger

  there are three flow spaces 131, 132,

  133. It can therefore be used for three different environments.

  ent. In this connection, it should be noted that the different flow spaces can be, in

  all annular heat exchangers represent

  tees, of different lengths, depending on where

  the angular boxes 112, 1121 or 112 "are placed.

  This has the advantage that in the case of the use of different first different media, it is possible to obtain

  these conditions of different heat exchange -

annuities.

  If the annular heat exchangers

  In the preferred embodiment of the invention, the invention is constructed from packs of flat tubes according to FIGS. 4 and 6,

  we have the surprising advantage, met for the first time

  first time, that here the annular heat exchanger can be constructed from packages of flat tubes 111 that can be manufactured virtually without loss of material in the cutting of the plates 123 and the strips 124 and 125. Another advantage consists in that these packets of flat tubes 111 and also the packets of flat tubes 11, according to the exemplary embodiment of FIGS. 1 and 2, can be used for annular heat exchangers of different sizes depending on the type of boxes angular 12,12 ', 12' ', 112,212,

112 '' that we use.

Claims (7)

  1. A heat exchanger comprising at least one bundle of flat tubes, which consists of flat tubes of equal length, provided for the flow of a first medium, which are mounted together so that their broad sides overlap each other. forming   intermediate spaces for the flow of one   the middle, and whose neighboring ends   each other are connected to an end wall.   mity which closes an opening of a collector box outside, wall through which the flat tubes open into a collecting chamber of the collector box, characterized in that the collector box has two openings for assembly, each time a end wall, each time a bundle of flat tubes, and by the   that the areas defined by these two openings   An angled box is formed between them so that the collector box forms an angular box which assembles two bundles of flat tubes in such a way that the flow directions of the flat tubes of the two bundles of flat tubes extend into this angle between them.   2.- Heat exchanger according to the   cation 1, characterized in that the angle between the two opening surfaces of the angular box has   a value of 1 / n of 360degrees and in that n   quets of equal flat tubes are assembled using n angular boxes of this kind to form a   annular heat exchanger with n sides.   3.- Heat exchanger according to any one   shell of claims 1 and 2, characterized in that   that at least one angular box is provided with a   connection tubing for the first medium.   4.- Heat exchanger according to any one   of claims 1, 2 and 3, characterized in that   in at least one angular box, a collecting chamber is associated with each of the two   openings and that the two chambers   these are separated from each other by an inner partition and are each provided with a tubing of   connection for the first medium.   5.- Heat exchanger according to the   cation 4, characterized in that at least two angular boxes divided in two are provided.   collector chambers, these angular   placing at least two listening spaces on each other   for a first environment or for at least two first different environments.   6.- Heat exchanger according to any one   one of claims 1 to 5, characterized in that   the flat tubes of at least one bundle of flat tubes are formed of rectangular plates which are connected alternately, preferably welded, to   different opposite edges, by strips.   7.- Heat exchanger according to any one   shell of claims 1 to 6, characterized in that   that the flat tubes of at least one bundle of flat tubes are formed of welded tubes or round tubes without seams, flattened by compression, the ends of which are joined to the edges of openings   a plate which forms the end wall of the quet of flat tubes.