Technical Field of the Invention
[0001] The present invention relates to the use of a heat exchanger comprising a plurality
of tubes, each tube being formed by bending a single sheet of plate or by joining
two sheets of plates and each tube being formed with a plurality of beads each having
a concave cross section, the tops of said beads being joined with the surface of the
opposite tube wall to form a plurality of divided passages in the tube.
Prior Art
[0002] In general, a conventionally known heat exchanger comprises a plurality of flat tubes
laminated in parallel, opposite ends of each tube being connected to two header pipes
disposed on both sides thereof respectively, and an inlet joint and an outlet joint
for introducing and discharging a heat exchange medium are provided at predetermined
places of the header pipes respectively. In the case of such a heat exchanger, the
heat exchange medium introduced into the flat tubes of the heat exchanger exchanges
its heat with the air circulating outside and the like while passing through the flat
tubes between header pipes back and forth several times, and is then discharged.
[0003] Each of the flat tubes used for such laminated type heat exchanger, for example,
such as one whose cross section is shown in Fig. 8, is formed into a flat tubular
form from a single rectangular brazing sheet. For instance, a flat tube 20 is formed
by joining the lateral edges of the single rectangular brazing sheet with each other
by brazing. In the figure, 20a and 20b denote flat joining portions at lateral ends
of the plate. These flat joining portions contribute to increase a joining area and
maintenance of the adequate joining strength with brazing.
[0004] Recently, there is an increasing tendency for reducing the wall thickness of the
tube as far as possible, mainly for reducing manufacturing cost by reducing the quantity
of material to be used, as well as for higher heat exchange efficiency and for lighter
tube weight. As the wall thickness of the flat tube 20 tends to be reduced, the structural
strength of such flat tubes are maintained by integrally forming a plurality of beads
21(21A, 21B) with each flat tube.
[0005] More particularly, a plurality of beads 21A and 21B are integrally formed with the
tube 20 at predetermined locations along its lateral direction, and the beads are
arranged along the longitudinal direction of the tube, the beads respectively projecting
to a level at which the tops of the beads abut the inner surface of the opposite tube
wall, whereby these beads 21A and 21B form a plurality of heat exchange medium passages
22, 22 inside the tube not only to increase a contact area of the tube with the medium
for higher heat exchange efficiency but also to increase a pressure resistance of
the tube itself by making the beads 21 to function as reinforcing members.
[0006] Besides the flat tube formed from a single plate, those formed by joining two plates
are also known. Both alternatives are, for example, disclosed in EP 0 704 667 A2.
[0007] Further, flat tubes obtained by an extrusion molding of an aluminium material or
an aluminium alloy material is known. Such a molded tube has internal passages divided
by laterally arranged partitions. The outer surface of such a molded flat tube is
provided with grooves each having a concave cross section for the purposes of increasing
a surface area, weight reduction, discharge of dew drops and the like. Such a tube
is, for example, disclosed in JP 63-091492.
Problems to be resolved by the Invention
[0008] In the case of the conventional tube for heat exchanger as described above, as shown
in Fig. 8, a recess resulting from the bead 21A located on the upstream side of the
air flow tends to heavily collect the dust x and the like carried by the air flow,
causing the problems such as the corrosion of the tube or the degradation of corrosion
resistance of the tube and resultant shorter lives of the parts.
[0009] Not only the recesses resulting from the formation of the beads but also the grooves
on the tubes formed by the extrusion molding for the purposes of increasing the surface
area, decreasing weight or saving of material to be used have been giving rise to
a problem that the dust collected in such recesses and grooves causes the corrosion
of the tubes.
[0010] More particularly, in general, in the case of conventional heat exchanger, the air
is made to flow in the lateral direction of the tube located between the radiating
fins which are disposed at upper and lower surfaces of the tube. As a result, the
surface of the tube, that is, the surface of the portion of the tube extending from
its front to the portion located on the upstream side of the air flow, is apt to collect
the dust contained in the air flow, while the surface of the portion of the tube on
the downstream side of the air flow is less apt to be contaminated with the dust.
Thus, when the recesses as described previously are located on the upstream side of
the air flow, the aforementioned tendency is promoted, causing the concentrative accumulation
of the dust in such recesses. Further, in contrast with that the dust collected in
the recesses facing downwardly on the outer surface of the lower tube wall can be
removed easily by falling, but the dust accumulated heavily in the recesses facing
upwardly cannot be removed easily, causing the corrosion of the tubes.
[0011] Further, there are chances that the rainwater is directly drawn into the inside of
the heat exchanger and that, depending on the conditions under which the heat exchange
takes place, condensation of moisture occurs in the vicinity of tubes and flows into
the recesses facing upwardly, thereby causing the dust accumulated in other places
to be carried into such recesses together with such condensed moisture.
[0012] Further, since the wall thickness of the tube itself is reduced for the purposes
such as cost reduction, weight reduction and higher efficiency of heat exchange with
outside medium, even minor corrosion can cause various troubles such as the degradation
of the pressure resistance or leakage of heat exchange medium.
[0013] Especially, in the case of the heat exchanger to be mounted on vehicles, the air
for cooling is introduced from outside, and thus the quantity of the dust contained
in the air is relatively greater, adding to the aforementioned adverse effect on the
tubes leading to the shorter life of the tube.
[0014] On the other hand, a type of tube in which the recess resulting from the bead facing
upwardly from the outer surface of the tube is depressed in advance to be joined integrally
with the tube wall has been proposed, for example, in the Japanese Patent Laid-Open
Publication No. 4-86489.
[0015] Such a type of tube, however, requires complex manufacturing steps that result in
high manufacturing cost.
[0016] Thus, it is an object of the present invention to realize a use of a heat exchanger
of the above mentioned kind, so that the dust is less apt to accumulate in the grooves,
thereby to achieve for the heat exchanger a higher corrosion resistance, which, in
turn, leads to a longer life.
Means for Solving the Problems
[0017] The problem is solved by using the heat exchanger as claimed in claims 1 and 3 of
the present application.
[0018] If the heat exchanger is used this way, the portion of the tube located on the most
upstream side of the air flow is provided with the recesses of the beads disposed
on the lower tube wall, so that dust is prevented from remaining in the recesses.
Thus, even when the recesses of the beads are formed on the upper tube wall on the
downstream side of the air flow, the dust in the air flow is caught by the radiating
fins and the like interposed between adjacent laminated tubes to enable relatively
clean air to circulate, so that the dust is less apt to remain in the recesses. As
a result, the corrosion resistance of the tube can be improved for longer life of
the heat exchanger. Further, the portion of the tube located on the most upstream
side of the air flow is apt to collect the dust, but the recesses are facing downwardly,
so that, even when the dust enters into the recesses, the dust falls easily, thereby
preventing the dust from remaining on the surface of the tube.
[0019] In a preferred embodiment recited in claim 2, the tops of said beads are joined with
the opposite flat surface of the tube wall or the tops of the beads formed on the
opposite tube wall, the bead located on the most upstream side of the air flow is
formed on the lower tube wall, and the beads located on the downstream side of the
air flow are formed projecting inwardly and alternately from the upper and lower tube
walls.
[0020] When the beads formed with the tube are made to project alternately from the upper
tube wall and lower tube wall along the direction of the air flow to be circulated,
the cross section of the molded tube becomes substantially symmetric with respect
to its upper tube wall and lower tube wall, whereby not only molding process of the
tube becomes easy but also the tops of the beads on the upper tube wall and the lower
tube wall are arranged symmetrically. As a result, the residual stress of the tube
material in the upper tube wall and the lower tube wall is made uniform, thereby contributing
to the increase in the pressure resistance of the tube itself and resultant increase
in durability and longer life of the heat exchanger.
[0021] When the tube is formed with the grooves by the extrusion molding, not only its surface
area is increased for a higher heat exchange efficiency but also the quantity of aluminium
or aluminium alloy material to be used can be reduced for lower manufacturing cost
and for light weight of the tube. Further, since the recess resulting from the groove
located on the most upstream side of the air flow is formed on the outer surface of
the lower tube wall, not only the dust and the like in the air is less apt to enter
the opening of the recess but also the dust collected in the opening can be removed
by falling, thereby preventing the dust or moisture from remaining on the surface
of the tube. As a result, the corrosion resistance of the tube is improved for longer
life.
Effects of the Invention
[0022] The recesses resulting from the beads on the most upstream side of the air flow face
downwardly, thereby preventing the dust from remaining in the recesses. Therefore,
even when the recesses facing upwardly resulting from the beads are formed on the
outer surface of the upper tube wall on the downstream side of the air flow, the dust
is less apt to remain in the recesses of the beads, since the dust and the like in
the air are caught by the radiating fins and the like interposed between the adjacent
tubes, and thus relatively clean air flows. As a result, the corrosion resistance
of the tubes will be increased for longer life of the heat exchanger. Further, the
portion of the tube on the most upstream side of the air flow is apt to collect the
dust and the like contained in the air flow, but the dust and the like passing the
recesses resulting from the beads are less apt to accumulate therein by falling easily,
since the recesses face downwardly, thereby preventing the accumulation of the dust
on the surface of the tube.
[0023] When the beads of the tube are formed projecting alternately from the upper and lower
tube walls in the direction of air flow, the formed tube has a substantially symmetrical
cross section with respect to its upper half and lower half, thereby making the formation
easier. Further, the beads are formed symmetrically on the upper wall and lower wall,
and, as a result, the residual stress occurring in the tube material is distributed
evenly to equalize the strength of the upper wall of the tube and that of the lower
wall of the tube, thereby contributing to the increase in pressure resistance of the
tube. This further contributes to the maintenance of the necessary durability and
longer life of the heat exchanger.
[0024] When the grooves are provided on the tubes formed by the extrusion, not only the
surface area of each tube can be increased for the higher heat exchange efficiency
but also the quantity of the material such as the aluminium material or aluminium
alloy material can be reduced for reduction of manufacturing cost and weight of the
tube. Further, the recess resulting from the groove located on the upstream side of
the air flow faces downwardly from the lower tube wall, so that not only the dust
and the like in the air are less apt to accumulate in the opening of the recesses
but also the dust and the like accumulated in the recess fall easily, thereby preventing
the dust or the moisture from remaining on the surface of the tube and contributing
to the increase in the corrosion resistance and longer life of the tube.
[0025] As described above, the present invention realizes a use of a heat exchanger, each
tube being provided with recesses made by beads or grooves on the upper and lower
outer surfaces of the tube, and such recesses or grooves are formed to face upwardly
on the outer surface of the tube wall so that the dust is less apt to accumulate therein,
thereby to provide tubes for the heat exchanger having a higher corrosion resistance,
which, in turn, leads to a longer life.
Brief Description of the Drawings
[0026]
- FIG. 1
- A front view of a laminated type heat exchanger of a first embodiment of the present
invention.
- FIG. 2
- A perspective view taking along the line A-A in FIG. 1 and showing a cross section
of a flat tube.
- FIG. 3
- A cross-sectional view of the flat tube of the first embodiment of the invention.
- FIG. 4
- A cross-sectional view of the flat tube of the first embodiment of the invention.
- FIG. 5
- A cross-sectional view of the flat tube of a second embodiment of the invention.
- FIG. 6
- A cross-sectional view of the flat tube of a third embodiment of the invention.
- FIG. 7
- A cross-sectional view of the flat tube of a fourth embodiment of the invention.
- FIG. 8
- A cross-sectional view of a conventional flat tube for the heat exchanger.
Embodiments of the Invention
[0027] A first embodiment of the present invention will be described referring to Fig. 1
and Fig. 2. In the embodiments which will be described hereafter, the basic construction
of the heat exchanger comprising the flat tubes as described in this embodiment is
common and thus the description thereof will be omitted by assigning same reference
numerals.
[0028] In Fig. 1, a laminated type heat exchanger 1 comprises two units of vertically installed
header pipes 3, 4, a plurality of flat tubes 2 of equal length parallelly laminated
one another with thin corrugated fins 5 interposed between the tubes, the tubes being
disposed between the two header pipes, the opposite ends of these flat tubes being
communicatively connected to the header pipes. Further, as shown in Fig. 2, the top
of each corrugated fins 5 is in contact with the flat surface of the flat tube 2.
[0029] The top and bottom openings of each of the header pipes 3 and 4 are closed with blank
caps 6. The header pipe 3 provided with an inlet joint 3a at its predetermined location
for introducing a heat exchange medium from outside, while the header pipe 4 is provided
with an outlet joint 4a at its predetermined location for discharging the medium,
which has undergone heat exchange process, maintaining the communication between the
header pipes. Further, the inside of the header pipe 3 and that of the header pipe
4 are respectively divided by partitions 7. Further, in Fig. 1, reference numeral
8 denotes side plates disposed on the top and bottom of the laminated flat tubes 2,
the side plates 8, 8 being designed to protect the corrugated fins 5 and to reinforce
the structural strength of the heat exchanger 1.
[0030] The heat exchange medium introduced through the inlet joint 3a circulates, or flows
through the tubes 2 arranged in zigzag, between the header pipe 3 on the left and
the header pipe 4 on the right by making a plurality of turns, bringing about the
heat exchange effect during the circulation, and is discharged through the outlet
joint 4a. That is, the medium introduced into the heat exchanger 1 is made to meander
downwardly through each of the group units of flat tubes, each group unit comprising
a predetermined number of the flat tubes.
[0031] As shown in Fig. 3 and Fig. 4, each of the tubes 2 is formed by bending, a sheet
of plate, and joining the opposite ends 2b and 2a of the material. A plurality of
beads 11A and 11B, projecting alternately from both the outer surfaces 2A and 2B of
the flat tube wall, are integrally formed with each flat tube. The beads 11A and 11B,
making four rows in total, projects inwardly alternately from predetermined places
on the opposite walls of the flat tube 2, thereby providing five passages 12 having
substantially equal cross-sectional areas. By forming the tube in this way, not only
the contact area of the tube with the circulating medium can be increased to obtain
a higher heat exchange efficiency but also the pressure resistance of the tube 2 can
be increased by letting the beads 11A and 11B function as reinforcing members.
[0032] By properly determining the locations of these beads 11A and 11B, the dust carried
by the air flowing through the tubes 2 can be prevented to a greatest possible extent
from accumulating in the recesses 11a and 11b formed on the outer surfaces the tubes.
[0033] Further, since a flat-sheet type brazing sheet is formed into a flat tube, it is
easier for manufacturing that the cross section of the tube has a substantially vertically
symmetric form of upper and lower portions, because the portions of the flat-sheet
type material where the beads 11A and 11B are formed tend to have a small residual
stress or the strength differing from the other portions, which may adversely affect
the moldability of the material or cause deformation of the tube. Thus, it is not
desirable to form the beads 11A and 11B only on one of the tube walls but desirable
to form the beads symmetrically on opposite tube walls. Thus, in the case of this
embodiment, although the opposite walls of the tube 2 are not symmetrical, the above-described
desirable condition is satisfied to a practically problem-free level by providing
the equal number of beads 11A, 11B on the opposite walls.
[0034] More particularly, four rows of beads are formed alternately on the opposite tube
walls along the width of each tube, that is, the direction of the air to be circulated.
A first bead 11B (1) is projected upwardly from the lower wall; a second bead 11A
(2), downwardly from the upper wall; a third bead 11B (3), upwardly from the lower
wall; and a fourth bead 11A (4), downwardly from the upper wall.
[0035] Thus, as shown in Fig. 4, a recess 11b resulting from the bead 11B facing downwardly
from the lower wall of the tube 2 is located in the vicinity of the portion of the
tube facing the flow of the air passing the heat exchanger 1, so that the dust x is
prevented from easily accumulating in the recess 11b. Since the dust is apt to accumulate
on the most upstream side of the circulating air flow, it is impossible to completely
prevent the dust x from being accumulated in the recess 11b resulting from the bead
11B; however, even in this case, the dust easily falls from the recess 11b to be removed,
so that the dust x is prevented from remaining in the recess 11b. Furthermore, on
the downstream side of the air flow, the recesses 11b and 11a resulting from the bead
11A and bead 11B are alternately located on the upper wall and lower wall of the tube
2, and so the dust and the like in the flowing air is caught by the radiating fins
5 located on the top and bottom of the tube 2, thereby allowing relatively clean air
to circulate, so that the dust is less apt to accumulate in the recesses 11a and 11b
resulting from the beads.
[0036] Presumably, the dust and the like removed from the flowing air and the dust removed
from the bead 11B of the tube 2 and the like may be caught by the corrugated fins
5, will cause the corrosion of the corrugated fins. However, the damage to the heat
exchanger is smaller when caused by the corrosion of the corrugated fins 5, since
the fin is passed by only the flow of the air, than the damage caused by the corrosion
of the tubes, since tubes are passed by the flow of the heat exchange medium, and
so the damage caused by the corrosion of the entire heat exchanger can be minimized.
[0037] Further, in Fig. 3 and Fig. 4, arrow marks directing rightward indicates the direction
of circulating air, and an arrow directing downward indicates the direction of falling
dust x.
[0038] As described above, on the most upstream side facing the flow of the air, the recess
resulting from the bead faces downwardly on the outer surface of the lower tube wall,
so that the accumulation of the dust and the like can be prevented. Even when the
recess resulting from the bead is formed on the outer surface of the upper tube wall
on the downstream side of the air flow, the dust and the like are less apt to accumulate
in the recess resulting from the bead, since the recess is passed by relatively clean
flow of the air. Further, the upstream side of the tube facing the flow of the air
is apt to collect the dust and the like contained in the flowing air; however, the
recess is located on the outer surface of the lower tube wall, so that, even when
the dust or the like is caught by the recess resulting from the bead, the dust and
the like are easily removed by falling therefrom, thereby preventing the dust or moisture
from remaining therein and contributing to the maintenance of a higher corrosion resistance
and resultant longer life of the tube.
[0039] Next, the flat tubes for the heat exchanger according to a second embodiment of the
present invention will be described by referring to Fig. 5. In Fig. 5, arrow marks
indicate the direction of circulating air.
[0040] The flat tube 2 for the heat exchanger according to this embodiment is provided with
four rows of the beads like the case of the preceding embodiment but differs in the
arrangement of the beads. That is, the recesses resulting from the beads are located
away from the upstream side of the air flowing upper and lower surfaces of the tube,
so that the chances of accumulation of the dust and the like in the recesses can be
reduced further.
[0041] More particularly, of the four rows of the beads formed in the direction of the width
of the tube, i.e., in the direction of air flow, a first and a second beads are made
to project upwardly from the lower tube wall, while a third and a fourth beads are
made to project downwardly from the upper tube wall. The dust and the like in the
air flow are gradually caught by the radiating fins and the like while the air flows
along the direction of the width of the tube, so that the accumulation of the dust
in the recesses can be prevented by collectively locating the recesses projecting
from the lower tube wall as remote as possible from the portion of the tube first
facing the air flow. On the other hand, the first and second beads 11B (1) and 11B
(2), projecting upwardly from the lower tube wall, and the third and fourth beads
11A (3) and 11A (4), projecting downwardly from the upper tube wall, are formed symmetrically
with respect to the right and left respectively along the direction of the width of
the tube in order for the tube to avoid the adverse effect on moldability of the tube
and deformation of the tube.
[0042] Next, the flat tube for the heat exchanger acceding to a third embodiment of the
present invention is described by referring to Fig. 6. In Fig. 6, arrow marks indicate
the direction of air flow.
[0043] In the case of the flat tube 2 for the heat exchanger according to this embodiment,
except the first bead located on the most upstream side of air flow, the second, third
and fourth beads respectively constitute beads 13A and beads 13B, respectively projecting
inwardly from the outer surface 2A of the upper tube wall and the outer surface 2B
of the lower tube wall. The beads 13A and 13B respectively project to substantially
a half of the inner height of the flat tube 2. The tops of the beads 13A and the tops
of the beads 13B are made to join with one another, thereby forming a plurality of
divided passages 12 in the flat tube 2. These beads 13A and 13B serve not only to
enhance the heat exchange efficiency by increasing the area of the tube in contact
with the medium passing these passages 12 but also to function as reinforcing members
to increase the pressure resistance of the tube.
[0044] Further, the first bead 11B (1) located on the most upstream side in the direction
of the width of the tube projects upwardly from the lower wall of the tube. The amount
of projection of this bead 11B (1) is set to be substantially equal to the inner height
of the flat tube 2, and the portion of the wall of the flat tube 2 confronting the
bead 11B (1) is left flat, but the top of the bead 11B (1) is joined with the inner
surface of the opposite wall of the flat tube 2.
[0045] In this fashion, the recess resulting from the bead is made to open downwardly on
the most upstream side of the air flow, so that the dust can be prevented from accumulating
in the recess resulting from the bead 11B (1).
[0046] Next, the flat tube for the heat exchanger according to the present invention is
described based on a fourth embodiment shown in Fig.7. The flat tube 2 for the heat
exchanger according to this embodiment differs from the preceding embodiment in that
the tube is formed by extruding an aluminum material. The inside of the tube is provided
with partitions 15 to divide the passage in the direction of width of the tube, forming
a plurality of divided passages 12. The flat tube 2 obtained by such an extrusion
molding is provided with recesses on its outer surface not only for increasing its
surface area but also for reducing its weight, which eventually result in the decrease
in the quantity of material to be used and resulting reduction of manufacturing cost.
[0047] More particularly, the flat tube 2 obtained by the extrusion molding is provided
with grooves 14A and 14B, each having a concave cross section, on the outer surface
2A of the upper wall and the outer surface 2B of the lower wall. These grooves 14A
and 14B, similar to the case of the preceding embodiment, are not only provided alternately
on the surfaces 2A and 2B of the upper wall and lower the tube walls but also arranged
so that the accumulation of the dust can be reduced. Further, in the case of this
embodiment, four rows of grooves 14A, 14B are provided alternately on the outer surface
2A of the upper wall and the outer surface 2B of the lower tube wall, a first groove
14B (1) being formed on the outer surface 2B of the lower tube wall and a second groove
14A (2) being formed on the outer surface 2A of the upper tube wall, a third groove
14B (3) being formed on the outer surface 2B of the lower tube wall, and a fourth
groove 14A (4) being formed on the outer surface 2A of the upper tube wall.
[0048] As described above, the first groove 14B (1) is formed on the outer surface 2B of
the lower wall in the vicinity of the portion of the tube facing the air flow, so
that the accumulation of the dust in a concave 14b resulting from the groove 14B (1)
can be prevented. Thus, even in the case of such flat tube obtained by the extrusion
molding and provided with the grooves for reducing the manufacturing cost and weight
too, it is possible to improve the corrosion resistance for longer life of the heat
exchanger 1.
[0049] Further, in this embodiment, the present invention is applied to the flat tube provided
with four rows of beads or grooves and five passages for the heat exchange medium
provided within the tube, but the application of the present invention is not limited
to the case of this embodiment and thus applicable to any other cases where any number
of beads or grooves are formed.
[0050] Further, in this embodiment, the intervals between the rows of the beads or grooves
arranged in the direction of the width of the tube are equalized, but such intervals
may be partially differentiated to any degree. Further, all the beads may be made
to project upwardly from the lower wall of the tube, as long as such arrangement will
not adversely affect the strength of the tube.
[0051] Further, in this embodiment, the beads are formed in succession in the direction
of the width of the tube, but the beads may be formed intermittently or irregularly,
or each of the beads may be formed with a gap provided at predetermined places for
communicating with the adjacent passages within the tube.
[0052] Further, in this embodiment, the flat tube is formed by bending a sheet of plate,
but this embodiment is not limited to the method of this embodiment. The tube may
be formed by joining two sheets of plates, and the tube may be provided with the beads
at predetermined locations in the manner similar to the case of the tube formed from
the single plate.
1. Verwendung eines Wärmetauschers (1) mit mehreren Röhren (2),
wobei jede Röhre (2) durch Biegen eines einzelnen Blechs oder durch Verbinden zweier
Bleche ausgeformt ist, und wobei an jeder Röhre (2) mehrere Wülste (11, 13) ausgeformt
sind, die jeweils einen konkaven Querschnitt haben, wobei die oberen Bereiche der
Wülste (11, 13) mit der Oberfläche der gegenüberliegenden Röhrenwand (2A, 2B) verbunden
sind, so dass mehrere aufgeteilte Durchgänge (12) in der Röhre (2) ausgebildet sind,
wobei der Wärmetauscher (1) so angeordnet ist, dass Luft entlang der Breite der Röhren
(2)von einer stromaufwärtigen Seite zu einer stromabwärtigen Seite des Wärmetauschers
(1) strömen kann, und wobei in jeder der Röhren (2) zumindest ein Wulst (11B, 13B)
von der unteren Röhrenwand (2B) am entfernten Ende der stromaufwärtigen Seite des
Luftstroms entlang des Wärmetauschers (1) nach oben hervorsteht, während alle Wülste
(11A, 13A), welche von der oberen Röhrenwand (2A) nach unten hervorstehen, stromabwärts
des zumindest einen aufwärts hervorstehenden Wulstes (11B, 13B) vorgesehen sind,
zum Austauschen von Wärme zwischen einem Wärmetauschermedium, das durch die Röhren
(2) hindurchtritt, und dem Luftstrom, der den Wärmetauscher (1) passiert.
2. Verwendung eines Wärmetauschers (1) nach Anspruch 1, wobei die oberen Bereiche der
Wülste (11, 13) mit der gegenüberliegenden flachen Oberfläche der Röhrenwand (2A,
2B) oder den oberen Bereichen der Wülste (11, 13), an der gegenüberliegenden Röhrenwand
(2A, 2B) verbunden sind, und wobei die Wülste (11, 13), die sich stromabwärts des
nach oben hervorstehenden Wulstes (11B, 13B) befinden, am entfernten Ende der stromaufwärtigen
Seite einwärts und abwechselnd von der oberen und der unteren Röhrenwand (2A, 2B)
hervorstehend ausgeformt sind.
3. Verwendung eines Wärmetauschers (1) mit mehreren Röhren (2),
wobei jede Röhre (2) aus einem Aluminiummaterial oder einem Aluminiumlegierungsmaterial
durch Extrusion ausgeformt ist, wobei die äußere Oberfläche jeder Röhre (2) mit mehreren
Nuten (14) versehen ist, die einen konkaven Querschnitt haben, und wobei jede Röhre
(2) mit Trennwänden (15) versehen ist, um das Innere der Röhre seitlich in mehrere
innere Durchgänge (12) aufzuteilen, wobei der Wärmetauscher (1) so angeordnet ist,
dass Luft von einer stromaufwärtigen Seite zu einer stromabwärtigen Seite des Wärmetauschers
(1) entlang der Breite der Röhren (2) strömen kann, und wobei in jeder der Röhren
(2) zumindest eine Nut (14B) in der unteren Röhrenwand am entfernten Ende der stromaufwärtigen
Seite des Luftstroms entlang des Wärmetauschers (1) ausgeformt ist, während alle Nuten
(14A), die in der oberen Röhrenwand (2A) ausgeformt sind, stromabwärts der zumindest
einen Nut (14B) vorgesehen sind,
zum Austauschen von Wärme zwischen einem Wärmetauschermedium, das durch die Röhren
(2) hindurchtritt, und dem Luftstrom, der den Wärmetauscher (1) passiert.