U.S. patent application number 12/499455 was filed with the patent office on 2009-10-29 for soldered heat exchanger network.
This patent application is currently assigned to BEHR GmbH & Co. KG. Invention is credited to Jurgen Hagele, Werner Helms.
Application Number | 20090266527 12/499455 |
Document ID | / |
Family ID | 34353007 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090266527 |
Kind Code |
A1 |
Helms; Werner ; et
al. |
October 29, 2009 |
SOLDERED HEAT EXCHANGER NETWORK
Abstract
The invention relates to a soldered heat exchanger network
comprising folded flat multichamber tubes and wave-like ribs that
are provided with fins. The multichamber tubes encompass at least
two chambers, each of which is formed by folded webs that are
soldered in the interior of the multichamber tube. According to the
invention, the wave-like ribs are provided with fin-free fields in
the area of the web or webs.
Inventors: |
Helms; Werner; (Esslingen,
DE) ; Hagele; Jurgen; (Stuttgart, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmbH & Co. KG
|
Family ID: |
34353007 |
Appl. No.: |
12/499455 |
Filed: |
July 8, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10572479 |
Aug 28, 2006 |
|
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PCT/EP04/10068 |
Sep 9, 2004 |
|
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12499455 |
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Current U.S.
Class: |
165/151 ;
165/177 |
Current CPC
Class: |
F28D 1/0391 20130101;
F28F 1/128 20130101 |
Class at
Publication: |
165/151 ;
165/177 |
International
Class: |
F28F 1/10 20060101
F28F001/10; F28F 1/06 20060101 F28F001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2003 |
DE |
103 43 905.6 |
Claims
1. A soldered heat exchanger network, comprising: folded
multichamber flat tubes, and corrugated ribs provided with gills,
wherein the multichamber tubes comprise at least two chambers which
are each formed by at least one folded web which is soldered in an
interior of the multichamber tube, wherein the corrugated ribs have
non-gilled areas in a region of the at least one web, wherein the
corrugated ribs include a plurality of constrictions that form
restricted regions and include at least one unrestricted region
without a constriction, wherein the at least one unrestricted
region is located in the region of the at least one web, wherein
the corrugated ribs directly contact walls of the multichamber
tubes at a position where the at least one web of the multichamber
tubes is located.
2. The soldered heat exchanger network as claimed in claim 1,
wherein the multichamber tube comprises a longitudinal soldered
seam.
3. The soldered heat exchanger network as claimed in claim 1,
wherein the multichamber tube comprises a longitudinal welded
seam.
4. The soldered heat exchanger network as claimed in claim 1,
wherein the corrugated ribs each comprise a smooth inflow region
and a smooth outflow region.
5. The soldered heat exchanger network as claimed in claim 1,
wherein the non-gilled areas have an equal and maximum rib height
H.
6. The soldered heat exchanger network as claimed in claim 1,
wherein regions of the corrugated ribs which are provided with
gills have a minimum rib height h.
7. The soldered heat exchanger network as claimed in claim 1,
wherein the multichamber tube comprises a soldered web at a
midpoint of a tube depth T and the corrugated ribs have two sets of
gills.
8. The soldered heat exchanger network as claimed in claim 1,
wherein the multichamber tube comprises (n) number of webs and the
corrugated ribs comprise (n+1) sets of gills.
9. The soldered heat exchanger as claimed in claim 3, wherein the
longitudinal welded seam is located on a narrow side of the
multichamber tube.
10. The soldered heat exchanger as claimed in claim 1, wherein the
at least one unrestricted region is located in a central region of
the corrugated ribs.
11. The soldered heat exchanger as claimed in claim 1, wherein the
at least one unrestricted region has a height H that is greater
than a height h of the restricted regions.
12. The soldered heat exchanger as claimed in claim 1, wherein the
at least one unrestricted region and the at least one web are
aligned with one another in a height direction of the soldered heat
exchanger network.
13. The soldered heat exchanger as claimed in claim 5, wherein the
at least one unrestricted regions correspond to the non-grilled
areas and have the height H, wherein the height H of the at least
one unrestricted regions is greater than a height h of the
restricted regions.
14. The soldered heat exchanger as claimed in claim 1, wherein the
multichamber flat tubes comprise at least two webs.
15. The soldered heat exchanger as claimed in claim 14, wherein an
unrestricted region is located in a region of each of the at least
two webs.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 10/572,479, filed Aug. 28, 2006, which is the National Stage of
International Application No. PCT/EP2004/010068, filed Sep. 9,
2004, which is based upon and claims the benefit of priority from
prior Federal Republic of Germany Patent Application No. 103 43
905.6, filed Sep. 19, 2003, the entire contents of all of which are
incorporated herein by reference in their entirety.
[0002] The invention relates to a soldered heat exchanger
network.
BACKGROUND
[0003] Heat exchangers, for example coolant radiators or
refrigerant condensers for motor vehicles, have a heat exchanger
network comprising tubes and ribs, with coolant or refrigerant, for
example, flowing through the tubes, and cooling air, in particular
ambient air, flowing over the ribs. In soldered cooling systems,
the tubes are embodied as flat tubes and the ribs are embodied as
corrugated ribs which are soldered at their wave peaks to the flat
longitudinal sides of the flat tubes. Flat tubes of large depth,
that is as measured in the direction of the airflow, are often
embodied as so-called multichamber tubes, that is to say, in order
to divide individual chambers, they have webs which act as tie-rods
and thus prevent the flat pipes from swelling or inflating as a
result of the inner pressure. In folded multichamber tubes, it is
therefore important that all the webs are uniformly soldered so
that the required internal pressure stability of the flat pipe is
maintained.
[0004] Heat exchanger networks of this type are produced by cutting
flat tubes and corrugated ribs to length and then "bundling" them
in a suitable device, that is to say arranging the corrugated ribs
adjacent to the flat pipes and joining them to form a block which
is subsequently clamped and soldered (if appropriate to the
associated tube ends or collecting tubes) in a soldering furnace.
The clamping presses both the peaks of the corrugated ribs against
the flat tubes and also the folded webs against the inner wall of
the flat tubes. This contact pressure must be as uniform as
possible in order to ensure as uniform and complete a solder as
possible. Folded multichamber tubes, multichamber tubes for short,
are known in various forms from the prior art, for example from
EP-A 302 232 by the applicant. The known flat tube has, for
example, a central web which is soldered to the opposite side of
the flat tube and thus forms two chambers. A modified form of tube
additionally has two beads (webs) which are folded from the tube
material and are soldered to the opposite side of the tube and form
four chambers in total. Folded multichamber flat tubes are known
from EP-A 457 470 in which folded webs are alternately formed from
opposite sides of the tube and are in each case soldered to the
opposite inner wall of the tube. In addition, multichamber tubes
are known which have opposing folded webs which only extend as far
as the centre of the inner width of the tube and are soldered to
one another there. The multichamber tubes can be embodied in one
piece, that is to say can be provided with a longitudinal welded
seam, or can be embodied in two pieces, that is to say with folded
and soldered longitudinal seams arranged at the narrow sides. The
applicant has disclosed a further form of folded multichamber flat
tube in DE-A 102 12 300, in which a method of production is also
described.
[0005] As already mentioned, corrugated ribs, which have gills or
sets of gills in order to improve the transfer of heat, are
arranged between the flat tubes. Sets of gills such as this can, as
shown for example in EP-B 547 309, be arranged in a continuous
fashion in the direction of airflow or--as described in U.S. Pat.
No. 4,693,307--be arranged in individual sets of gills, between
which are situated smooth, that is to say non-gilled, corrugated
rib regions.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0006] The applicant has established that when folded multichamber
flat tubes having corrugated ribs to are soldered form a heat
exchanger network, defects can occur which lead to the flat tubes
"inflating", this being attributable to insufficient soldering of
individual webs to the opposing tube inner wall.
[0007] It is therefore an object of the present invention to
improve a soldered heat exchanger network of the type mentioned in
the introduction using suitable measures such that faultless
soldering is carried out both on the outside and the inside of the
multichamber flat tubes.
[0008] According to the invention, it is provided that the
corrugated ribs are of smooth design in the region of the webs,
that is to say are not provided with gills. "In the region of the
webs" is intended to mean: as an extension of the webs in a
transverse direction with respect to the flat sides of the
multichamber tube. Gills or sets of gills are arranged in the
regions between the webs, so that the chambers of the multichamber
flat tube are each associated with sets of gills at approximately
the same depth. The inventors have established that a "gilled"
corrugated rib does not have a uniform rib height but rather a
lower rib height, the minimum height, is present in the regions of
the individual sets of gills than in the smooth, that is to say
non-gilled regions, where there is a larger rib height, the maximum
height. This irregularity in the rib height is attributable to the
fact that the cutting and subsequent "twisting out" of the gills
results in the corrugated rib being "pulled in" in the region of
the gills, that is to say there is an element of fitting to size.
The inventors have utilized this observation and matched the
corrugated rib with its gilled arrangement to the multichamber flat
tubes. This brings about the advantage that when the heat exchanger
network is clamped after bundling, a uniform contact pressure is
exerted on all the webs via the corrugated ribs. This subsequently
leads to uniform, fixed soldering of all the webs so that they can
fulfill their tie-rod function to the full extent and thus prevent
the tubes from "inflating".
[0009] In an advantageous embodiment of the invention, the
multichamber flat tubes have longitudinal seams which are either
soldered or welded and are preferably arranged on one or both
narrow sides of the multichamber flat tube. As a result,
asymmetries on the flat sides of the tubes, which could adversely
affect the soldering process, are avoided.
[0010] In a further advantageous embodiment of the invention, the
corrugated ribs also have smooth regions on the inflow and outflow
sides. Above all, straight inflow and outflow edges and a laminar
entry region for the airflow are obtained as a result.
[0011] In a further advantageous embodiment of the invention, the
smooth regions of the corrugated ribs each have an equal and
maximum rib height. This ensures that the same contact pressure is
exerted on all webs, and that the joint gap between the ridge of
the web and the inner wall of the tube is minimized in a uniform
manner. Uniform soldering, with sufficient strength for a tie-rod
effect, is obtained as a result.
[0012] In a further embodiment of the invention, the regions which
are provided with gills have a minimum rib height. In this way,
when the network is clamped, the clamping force does not act as an
area load on the wave peaks but acts directly on the webs in
approximately the manner of point-loads, and as a result, the flat
tubes are pressed together in the region of the webs until they
come into contact.
[0013] In a further embodiment of the invention, the multichamber
tube has two identical chambers which are separated by means of a
central web, in the region of which the corrugated ribs are of
smooth design. This is the most simple form of multichamber tube,
which is used for relatively small system depths.
[0014] In a further advantageous embodiment of the invention, the
number of chambers or webs can be increased by any desired number,
two webs with three chambers being a preferred solution for motor
vehicle heat exchangers.
[0015] An exemplary embodiment of the invention is described in
more detail in the following and is illustrated in the drawing, in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a corrugated rib in a view from above,
[0017] FIG. 1a shows the corrugated rib of FIG. 1 in a side view
and
[0018] FIG. 2 shows a multichamber tube having lateral corrugated
ribs.
DETAILED DESCRIPTION
[0019] FIG. 1 shows a corrugated rib 1 in a view from above, FIG.
1a shows the corrugated rib 1 in a side view. The corrugated rib 1
serves as a secondary heat exchange area in air-cooled flat tube
systems or heat exchanger networks. The corrugated rib 1 is
subjected to a flow of air (ambient air) flowing in the direction
of the arrow L, and has a depth T in the airflow direction L. The
rib height corresponds to the amplitude of the wave pattern (cf.
FIG. 1a) and is denoted by H. The corrugated rib 1 is preferably
produced from a thin aluminium sheet, into which are cut gills 2 on
the air side in order to improve the exchange of heat, which gills
2 are arranged in the form of sets of gills 3, 4 on the rib
surface. The ribs 2 are--as is not illustrated here but is
disclosed by the prior art (EP-B 547 309 or U.S. Pat. No.
4,693,307) cited in the introduction--inclined relative to the rib
surface and in this way form a so-called gill angle. This method of
production of the gills 2, that is to say the cutting and
subsequent twisting of the rib material, results in a constriction,
illustrated by the dashed lines 5, in the region of the sets of
gills 3, 4. Said constrictions lead to a reduction in the rib
height H. The reduced rib height is denoted by h and represents the
minimum rib height. The maximum rib height is denoted by H and
protrudes beyond the sets of gills 3, 4, that is to say, in FIG. 1,
at the inflow and outflow sides and in the centre of the corrugated
rib 1. As illustrated in FIG. 1a, the corrugated rib 1 has wave
peaks 1a, 1b, by means of which the corrugated rib 1 bears against
the tubes (not illustrated here). On account of the constrictions
5, the wave peaks 1a, 1b therefore do not form a continuous
straight line. The gills 2 project into the airflow.
[0020] FIG. 2 shows a folded multichamber tube 6 which has two flat
longitudinal sides 6a, 6b and two rounded narrow sides 6d, 6c. Two
webs 7, 8 are formed out of the upper longitudinal side 6a by means
of folding, which webs 7, 8 are soldered to the opposite
longitudinal side 6b and thus form tie-rods. The multichamber tube
6 is produced from sheet metal which is closed at the narrow side
6d by means of a longitudinal welded seam 9. The multichamber tube
6 thus has three chambers 10, 11, 12 in which a coolant or
refrigerant flows. Outside the multichamber tube 6, corrugated ribs
13, 14 are arranged on its longitudinal sides 6a, 6b, which
corrugated ribs 13, 14 are soldered to the multichamber tube 6. The
corrugated ribs 13, 14 and the multichamber tube 6 thus constitute
a section of a heat exchanger network (not illustrated) which is
constructed in accordance with this pattern and can be used in
coolant radiators or refrigerant condensers for motor vehicles. The
corrugated ribs 13, 14 each have three sets of gills 15a, 15b, 15c
and 16a, 16b, 16c, between which remain non-gilled, that is to say
smooth, regions 17a, 17b and 18a, 18b. The arrangement of the sets
of gills 15a, 15b, 15c, 16a, 16b, 16c is selected such that they
are situated in the region of the chambers 10, 11, 12, and the
smooth regions 17a, 17b, 18a, 18b are arranged in the region of the
webs 7, 8. As explained above, said corrugated ribs also have a
reduced rib height on account of the sets of gills 15a to c and 16a
to c, and a maximum rib height H in the smooth regions 17a, 17b,
18a, 18b. On account of the selected arrangement, the maximum rib
heights H are situated, as seen in the direction of depth, at the
level of the webs 7, 8 and at the inflow and outflow sides of the
corrugated ribs 13, 14. As explained in the introduction, the
corrugated ribs 13, 14 and multichamber tubes 6 are bundled to form
a heat exchanger network and are subsequently clamped using
suitable clamping means in order to prepare for the soldering
process. In the process, clamping forces occur between the
corrugated ribs 13, 14 and the multichamber tubes 6, which clamping
forces are illustrated here by arrows F, each pointing in the
direction of the webs 7, 8. In said clamping process, the webs 7, 8
are thus pressed against the inner wall of the longitudinal side 6b
of the tube, so that there is a minimum joint gap at the contact
points. This ensures complete soldering and thus provides the
multichamber tube 6 with the required internal pressure
stability.
[0021] The invention is explained on the basis of the above
exemplary embodiment, that is to say for a multichamber tube having
two webs and three chambers. Variations both in terms of shape and
also in terms of the number of webs and thus the number of chambers
likewise fall within the scope of the invention. An essential
aspect of all embodiments is that the clamping forces exerted on
the multichamber tube by the corrugated tubes are always directed
towards the webs and bring about the required contact pressure
there.
* * * * *