U.S. patent application number 15/737548 was filed with the patent office on 2018-07-05 for heat exchanger and associated method for producing same.
This patent application is currently assigned to Valeo Systemes Thermiques. The applicant listed for this patent is Valeo Systemes Thermiquese. Invention is credited to Kamel Azzouz, Patrick Boisselle, Samuel Bry, Xavier Marchadier.
Application Number | 20180187985 15/737548 |
Document ID | / |
Family ID | 54329674 |
Filed Date | 2018-07-05 |
United States Patent
Application |
20180187985 |
Kind Code |
A1 |
Boisselle; Patrick ; et
al. |
July 5, 2018 |
HEAT EXCHANGER AND ASSOCIATED METHOD FOR PRODUCING SAME
Abstract
The present invention concerns a heat exchanger (1) comprising:
a tube bundle (2) comprising a plurality of tubes (20) arranged
parallel to each other and spacers (21) arranged between said tubes
(20), a collector plate (4) comprising holes (43) respectively
bordered by first flanges (44) into which ends (22) of the tubes
(20) are inserted, the tube bundle (2) being brazed and the
collector plate (4) comprising at least one compressible seal (41)
forming second flanges (45), the second flanges (45) being
compressed between the first flanges (43) and the ends (22) of the
tubes (20) in order to provide a tight seal between said ends (22)
of the tubes (20) and the corresponding first flanges (43).
Inventors: |
Boisselle; Patrick; (Le
Mesnil Saint Denis, FR) ; Azzouz; Kamel; (Le Mesnil
Saint Denis, FR) ; Bry; Samuel; (Le Mesnil Saint
Denis, FR) ; Marchadier; Xavier; (Le Mesnil Saint
Denis, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Valeo Systemes Thermiquese |
Le Mesnil Saint Denis |
|
FR |
|
|
Assignee: |
Valeo Systemes Thermiques
Le Mesnil Saint Denis
FR
|
Family ID: |
54329674 |
Appl. No.: |
15/737548 |
Filed: |
June 22, 2016 |
PCT Filed: |
June 22, 2016 |
PCT NO: |
PCT/EP2016/064340 |
371 Date: |
December 18, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 9/165 20130101;
F28F 2265/26 20130101; F28F 1/025 20130101; F28F 2275/125 20130101;
F28F 9/0224 20130101; F28F 2275/04 20130101 |
International
Class: |
F28F 9/16 20060101
F28F009/16; F28F 1/02 20060101 F28F001/02; F28F 9/02 20060101
F28F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 22, 2015 |
FR |
1555677 |
Claims
1. A heat exchanger comprising: a tube bundle comprising a
plurality of tubes arranged parallel to each other and spacers
arranged between said tubes; and a collector plate comprising holes
respectively bordered by first flanges into which ends of the tubes
are inserted, wherein the tube bundle is brazed and the collector
plate comprises at least one compressible seal forming second
flanges, the second flanges being compressed between the first
flanges and the ends of the tubes in order to provide a tight seal
between said ends of the tubes and the corresponding first
flanges.
2. The heat exchanger as claimed in claim 1, wherein at least the
end of each tube has an oblong cross section.
3. The heat exchanger as claimed in claim 1, wherein the ends of
the tubes comprise a first flaring and a bearing area compressing
the compressible seal.
4. The heat exchanger as claimed in claim 1, wherein the ends of
the tubes comprise at least one second flaring extending above the
compressible seal.
5. The heat exchanger as claimed in claim 4, wherein the second
flaring is produced over a limited portion of the ends of the
tubes.
6. The heat exchanger as claimed in claim 1, wherein the rate of
compression of said second flanges is between 25% and 35%.
7. A method for producing a heat exchanger as claimed in claim 1,
comprising the following steps: a) assembling a tube bundle
comprising a plurality of tubes arranged parallel to each other and
spacers arranged between said tubes, b) brazing the tubes to the
spacers, c) assembling a collector plate provided with holes
bordered by first flanges with a cross section corresponding to the
ends of the tubes and equipped with a compressible seal forming
second flanges suitable for being engaged respectively through the
holes, d) inserting the ends of the tubes into the holes of the
collector plate so as to compress the second flanges of the
compressible seal.
8. The method as claimed in claim 7, wherein the step d) of
inserting the ends of the tubes into the holes of the collector
plate so as to compress the second flanges comprises a first
sub-step of inserting the ends of the tubes into the holes of the
collector plate and a second sub-step of producing a first flaring
and a bearing area at the ends of the tubes.
9. The method as claimed in claim 7, wherein the step d) of
inserting the ends of the tubes into the holes of the collector
plate so as to compress the second flanges comprises a step of
press-fitting the ends of the tubes into the holes of the collector
plate, at least said ends being larger in size than the openings of
the second flanges.
10. The method as claimed in claim 7, further comprising an
additional step of producing at least one second flaring at the
ends of the tubes extending above the compressible seal.
11. The method as claimed in claim 10, wherein the second flaring
is produced over a limited portion of the ends of the tubes.
Description
[0001] The invention concerns a heat exchanger, in particular for a
motor vehicle, and the method for producing same.
[0002] More particularly, it concerns a heat exchanger comprising a
plurality of tubes between which spacers are inserted. The tubes
are generally tubes with an oval or oblong cross section, defined
by a major axis and a minor axis, and having ends inserted into
holes of a collector plate. In order to ensure tight sealing and
facilitate production, the tubes, the spacers and the collector
plate are generally made from a metal material and attached
together during a single brazing step.
[0003] However, during the use of the heat exchanger, the link
between the tubes and the collector plate is rigid and cannot
compensate for expansion and retraction phenomena resulting from
temperature variations. Over time, these links weaken, and
breakages or leaks can occur.
[0004] One of the aims of the present invention is therefore to at
least partially overcome the problems of the prior art and propose
an improved heat exchanger and the method for producing same.
[0005] The present invention therefore concerns a heat exchanger
comprising: [0006] a tube bundle comprising a plurality of tubes
arranged parallel to each other and spacers arranged between said
tubes, [0007] a collector plate comprising holes respectively
bordered by first flanges into which ends of the tubes are
inserted,
[0008] the tube bundle being brazed and the collector plate
comprising at least one compressible seal forming second flanges,
the second flanges being compressed between the first flanges and
the ends of the tubes in order to provide a tight seal between said
ends of the tubes and the corresponding first flanges.
[0009] Using a compressible seal or a plurality of compressible
seals to create the link between the bundle and the collector plate
provides a certain flexibility that can absorb the expansions and
retractions resulting from temperature variations. The link between
the bundle and the collector plate is therefore more resistant to
these temperature variations. There is a synergistic effect between
the flexibility of the link, between the bundle and the collector
plate plate, and the fact that the bundle is brazed. As a result of
this, the heat exchanger offers optimum thermal performances, due
to the brazed bundle, and improved resistance to temperature
variations, due to the link between the bundle and the collector
plate plate. Moreover, because the collector plate is not brazed,
said collector plate can be thinner and there is less of a need to
reinforce the collector.
[0010] According to one aspect of the invention, at least the end
of each tube has an oblong cross section.
[0011] According to another aspect of the invention, the ends of
the tubes comprise a first flaring and a bearing area compressing
the compressible seal.
[0012] According to another aspect of the invention, the ends of
the tubes comprise, in addition to or as an alternative to the
first flaring, at least one second flaring extending above the
compressible seal. It is therefore understood that the ends of the
tubes can comprise the first flaring or the second flaring,
separately, or indeed the first and the second flaring.
[0013] According to another aspect of the invention, the second
flaring is produced over a limited portion of the ends of the
tubes.
[0014] According to another aspect of the invention, the rate of
compression of said second flanges is between 10% and 50% and
preferably between 25% and 35%.
[0015] The invention also concerns a method for producing a heat
exchanger as previously described and comprising the following
steps: [0016] a) assembling a tube bundle comprising a plurality of
tubes arranged parallel to each other and spacers arranged between
said tubes, [0017] b) brazing the tubes to the spacers, [0018] c)
assembling a collector plate provided with holes bordered by first
flanges with a cross section corresponding to the ends of the tubes
and equipped with a compressible seal forming second flanges
suitable for being engaged respectively through the holes, [0019]
d) inserting the ends of the tubes into the holes of the collector
plate so as to compress the second flanges of the compressible
seal.
[0020] According to one aspect of the method according to the
invention, the step d) of inserting the ends of the tubes into the
holes of the collector plate so as to compress the second flanges
comprises a first sub-step of inserting the ends of the tubes into
the holes of the collector plate and a second sub-step of producing
a first flaring and a bearing area at the ends of the tubes.
[0021] According to another aspect of the method according to the
invention, the step d) of inserting the ends of the tubes into the
holes of the collector plate so as to compress the second flanges
is a step of press-fitting the ends of the tubes into the holes of
the collector plate, at least said ends being larger in size than
the openings of the second flanges.
[0022] According to another aspect of the method according to the
invention, the method comprises an additional step of producing at
least one second flaring at the ends of the tubes extending above
the compressible seal.
[0023] According to another aspect of the method according to the
invention, the second flaring is produced over a limited portion of
the ends of the tubes.
[0024] Other features and advantages of the invention will become
clearer on reading the description that follows, provided as an
illustrative and non-limiting example, and viewing the appended
drawings in which:
[0025] FIG. 1 shows a schematic perspective view of a heat
exchanger,
[0026] FIG. 2 shows a schematic cross-sectional perspective view of
a heat exchanger,
[0027] FIG. 3 shows a schematic exploded cross-sectional view of a
collector plate,
[0028] FIG. 3' shows a schematic cross-sectional view of the
collector plate of FIG. 3,
[0029] FIG. 4 shows a schematic view of the collector plate of FIG.
3 along the cutting plane XX,
[0030] FIG. 5 shows a schematic cross-sectional view of a heat
exchanger according to a first embodiment,
[0031] FIGS. 6 to 8 show a schematic cross-sectional view of a heat
exchanger according to a second embodiment during different steps
of production.
[0032] The elements that are identical in the different figures
have been given the same reference numbers.
[0033] The following embodiments are examples. Although the
description refers to one or more embodiments, this does not
necessarily mean that each reference concerns the same embodiment,
or that the features apply only to a single embodiment. Single
features of different embodiments may also be combined to provide
other embodiments.
[0034] In the present description, certain elements or parameters
may be numbered, for example as a first element or a second
element, as a first parameter and a second parameter, or indeed a
first criterion and a second criterion, etc. The purpose of this
numbering is simply to differentiate between and designate
elements, parameters or criteria that are similar but not
identical. This numbering does not imply priority of one element,
parameter or criterion over another, and such designations can
easily be interchanged without departing from the context of the
present description. Nor does this numbering imply an order in
time, for example in teams of appraising such or such criteria.
[0035] The heat exchanger 1 shown in FIGS. 1 and 2 comprises a
bundle 2 formed from a plurality of tubes 20 inside which a first
heat-transfer fluid can flow. The tubes 20 are arranged parallel to
each other and stacked. Between the tubes 20, spacers 21 are
arranged, acting as interference devices and increasing the surface
area for the exchange of heat with a second heat-transfer fluid
passing between said tubes 20. The tubes 20 and spacers 21 are
produced from a metal material and are brazed together in order to
form the bundle 2. Having a brazed bundle 2 helps improve the
thermal performances, i.e. the heat exchanges between the two
heat-transfer fluids, compared to a mechanically assembled bundle.
As shown in FIGS. 1 and 2, the tubes 20 preferably have an oblong
and relatively flat shape. Moreover, the tubes 20 can have an
internal spacer 26 between the inner walls of same. This spacer 26
helps provide said tubes 20 with a good level of rigidity.
[0036] The heat exchanger 1 also comprises two water collectors or
tanks arranged at each end 22 of the tubes 20. These collectors
comprise a collector plate 4 and a cover (not shown) that covers
said collector plate 4 and closes the collector. These collectors
are used to collect and/or distribute the first heat-transfer fluid
in order for it to flow in the tubes 20.
[0037] As shown in greater detail in FIG. 3', the collector plate 4
provides the sealed link between the collector and the brazed
bundle 2. Said collector plate 4 comprises a core 40, that can be
generally rectangular, delimiting a plurality of holes 43 that have
a cross section that matches the shape of the cross section of the
tubes 20 and that are capable of receiving the ends 22 of the
tubes. Each hole 43 is bordered by a first flange 44 turned towards
the inside of the bundle 2. The holes 43 are similar in size to the
openings of the first flanges 44. The first flanges 44 can
advantageously be formed as an integral part of the collector plate
4 and can be formed, for example, at the same time as the holes 43,
by drawing.
[0038] Since the shape of the holes 43 and the first flanges 44
matches that of the cross section of the tubes 20, or at least the
ends 22 of same, and this shape is generally oblong, it is possible
to characterize said holes 43 and first flanges 44 according to two
axes of different lengths. The length L1 corresponds to the longer
length and can correspond to the width of the hole 43, as shown in
FIGS. 3, 3' and 5 to 8. The length 11 corresponds meanwhile to the
shorter length and can correspond to the thickness of the hole 43,
as shown in FIG. 4. In order to allow the ends 22 of the tubes 20
to be inserted into the first flanges 44, the lengths L1 and l1 of
the hole 43 are larger than those of the ends 22 of the tubes 20.
Reference made here to the width and thickness of the holes 43
reflects that made to the width and thickness of the tubes 20 that
are intended to be inserted into said holes 43.
[0039] The core 40 is extended by a peripheral groove 42 that ends
with a peripheral rim 46 forming foldable tabs. The peripheral
groove 42 is intended to receive the rims of the cover, and the
peripheral rim 46 can be folded to attach said cover onto the
collector plate 4.
[0040] The collector plate 4 receives at least one compressible
seal 41, in particular to ensure tight sealing at the holes 43.
[0041] According to a first embodiment, shown in FIGS. 1 and 2, the
collector plate 4 can be provided with only a single compressible
seal 41. This compressible seal 41 comprises a core that is applied
against the core 40 of the collector plate 4. This core of the
compressible seal 41 is linked to a plurality of second flanges 45,
each of which is inserted into a hole 43. When the bundle 2 is
assembled with the collector plate 4, the second flanges 45 are
compressed between the first flanges 43 and the ends 22 in order to
ensure tight sealing between said ends 22 of the tubes 20 and the
corresponding first flanges 43. The rate of compression of the
flanges 45 is 30%. According to variants of the invention, the rate
is between 10% and 50% and preferably between 25% and 35%.
Moreover, the core of the compressible seal 41 can form, at its
periphery, a bead 47 arranged in the peripheral groove 42 and
capable of providing a tight seal with the cover when the
peripheral rim 46 is folded.
[0042] According to a second embodiment not shown here, the
collector plate 4 can comprise a plurality of compressible seals 41
that form flanges 45 that are each inserted into a hole 43 in order
to ensure tight sealing between the end 22 of a tube 20 and the
corresponding first flange 43. In this embodiment, tight sealing
with the cover can be ensured by a separate compressible seal
positioned in the peripheral groove 42.
[0043] Using a compressible seal 41 or a plurality of compressible
seals 41 for producing the link between the bundle 2 and the
collector plate 4, provides a certain flexibility that can absorb
the expansions and retractions resulting from temperature
variations. The link between the bundle 2 and the collector plate 4
is therefore more resistant to these temperature variations. There
is a synergistic effect between the flexibility of the link between
the bundle 2 and the collector plate 4, and the fact that the
bundle 2 is brazed. As a result of this, the heat exchanger 1
offers optimum thermal performances, due to the brazed bundle 2,
and improved resistance to temperature variations, due to the link
between the bundle 2 and the collector plate 4. Moreover, because
the collector plate 4 is not brazed, said collector plate 4 can be
thinner and there is less of a need to reinforce the collector.
[0044] The shape of the second flanges 45 also matches that of the
cross section of the tubes 20, or at least the ends 22 of same. It
is therefore possible to characterize said second flanges 45
according to two axes of different lengths. The length L2
corresponds to the width of the opening of the second flange 45
when the compressible seal 41 is not compressed, as shown in FIGS.
3, 3', 4 and 6. The length 12 corresponds to the thickness of the
opening of the second flange 45 when the compressible seal 41 is
not compressed, as shown in FIG. 4. When compressed, the opening of
the second flange 45 at at least one of these lengths (width and/or
thickness) increases, for example as shown in FIGS. 5, 7 and 8, in
which the width of the opening of the compressible seal 45 is
larger and corresponds to a length L2'. As before, reference made
here to the width and thickness of the openings of the second
flanges 45 reflects that made to the width and thickness of the
tubes 20 that are intended to be inserted into said openings of the
second flanges 45.
[0045] The ends 22 of the tubes 20 are larger in size than the
openings of the second flanges 45 but smaller in size than the
holes 43 in order to compress the compressible seal 41 at the
second flanges 45. Larger or smaller in size should be taken to
mean that there is a difference at least in width and/or thickness
between the tubes 20 and the holes 43 or the openings of the second
flanges 45.
[0046] As shown in FIG. 5, the body of a tube 20 and its end 22 can
be identical in width and thickness, i.e. the size (width and
thickness) of the tube 20 is constant within the bundle 2. The
compressible seal 41 is compressed because the width and the
thickness of the tube 20 as a whole is larger than that of the
openings of the second flanges 45 and smaller than that of the
holes 43.
[0047] On the contrary, and as shown in FIGS. 7 and 8, the body of
a tube 20 and its end 22 can have a different width and/or
thickness. The end 22 can have a seal flaring 23 referred to
hereinafter as the first flaring 23 on the inside of the bundle 2
and that increases the width and/or the thickness of said end 22.
The end 22 also comprises a bearing area 24 that is wider and/or
thicker than the rest of the body of the tube 20 as a result of the
first flaring 23 and that compresses the compressible seal 41.
[0048] The ends 22 of the tubes 20 can also comprise, as an
alternative or in addition to the first flaring 23, at least one
second flaring 25--a retaining flaring allowing mechanical
locking--on the outside of the bundle 2 and that extends over the
compressible seal 41 as shown in FIGS. 1, 2 and 8. This second
flaring 25 can be produced, in particular, over a limited portion
of the ends 22 of the tubes 20. This second flaring 25 allows, in
particular, the collector plate 4 to be immobilized and held in
position on the bundle 2. In the example shown in FIGS. 1 and 2,
the ends 22 of the tubes 20 each comprise two second flarings 25
produced over a limited portion. The first 23 and second 25
flarings of the ends 22 are situated to either side of the
collector plate 4.
[0049] The present invention also concerns a method for producing a
heat exchanger 1 as previously described and comprising the
following steps: [0050] a) assembling a tube bundle 2 comprising a
plurality of tubes 20 arranged parallel to each other and spacers
21 arranged between said tubes 20, [0051] b) brazing the tubes 20
to the spacers 21, [0052] c) assembling a collector plate 4
provided with holes 43 bordered by first flanges 44 with a cross
section corresponding to the ends 22 of the tubes 20 and equipped
with a compressible seal 41 forming second flanges 45 suitable for
being engaged respectively through the holes 43, [0053] d)
inserting the ends 22 of the tubes 20 into the holes 43 of the
collector plate 4 so as to compress the second flanges 45 of the
compressible seal 41.
[0054] According to one embodiment, and in particular when the size
of the end 22 of the tubes 20 is smaller than or equal to the size
of the opening of the second flanges 45, this last step d) can
comprise a first sub-step of inserting the ends 22 of the tubes 20
into the holes 43 of the collector plate 4 and a second sub-step of
producing the first flaring 23 and the bearing area 24 at the ends
22 of the tubes 20. This first sub-step is shown in FIG. 6, and the
insertion is therefore easy to carry out because the end 22 of the
tube 20 is smaller than or equal in size to the opening of the
second flange 45, and the compressible seal 41 is compressed by
forming the first flaring 23 and the bearing area 24, as shown in
FIGS. 7 and 8. This first flaring 23 and the bearing area 24 can be
produced, for example, by using a punch with a shape corresponding
to that of the ends 22 of the tubes 20.
[0055] According to another embodiment, the step d) of inserting
the ends 22 of the tubes 20 into the holes 43 of the collector
plate 4 so as to compress the second flanges 45 of the compressible
seal 41 can be a step of press-fitting the ends 22 of the tubes 20
into the holes 43 of the collector plate 4. In order for the
compressible seal 41 to be compressed, at least the ends 22 of the
tubes 20 are larger in size than the openings of the second flanges
45, either because the tube 20 as a whole is generally larger in
size, as shown in FIG. 6, or because a first flaring 23 and a
bearing area 24, as shown in FIGS. 7 and 8, have been produced in
advance on the ends 22 of the tubes 20.
[0056] The production method can also comprise an additional step
of producing at least one second flaring 25 extending above the
compressible seal 41 as shown in FIGS. 1, 2 and 8. This second
flaring 25 can be produced over a limited portion of the ends 22 of
the tubes 20.
[0057] It is therefore clear that the heat exchanger 1 according to
the invention offers optimum thermal performances, due to the
brazed bundle 2, and improved resistance to temperature variations,
due to the mechanical link between the bundle 2 and the collector
plate 4.
* * * * *