U.S. patent application number 13/807478 was filed with the patent office on 2013-08-01 for heat exchanger tube, heat exchanger comprising such tubes and method for producing one such tube.
This patent application is currently assigned to VALEO SYSTEMES THERMIQUES. The applicant listed for this patent is Alain Bauerheim, Kevin Gahon, Philippe Metayer, Laurent Moreau, Yoann Naudin. Invention is credited to Alain Bauerheim, Kevin Gahon, Philippe Metayer, Laurent Moreau, Yoann Naudin.
Application Number | 20130192811 13/807478 |
Document ID | / |
Family ID | 43757841 |
Filed Date | 2013-08-01 |
United States Patent
Application |
20130192811 |
Kind Code |
A1 |
Moreau; Laurent ; et
al. |
August 1, 2013 |
Heat Exchanger Tube, Heat Exchanger Comprising Such Tubes And
Method For Producing One Such Tube
Abstract
Heat exchanger tube (100), in particular the condenser of a
motor vehicle air conditioning system, is disclosed. The tube
comprises a folded wall (105) defining a housing (115), and an
internal separator (130), inserted into said housing, said internal
separator defining a plurality of fluid circulation channels (136),
said wall (105) having large surfaces connected by radii. The tube
(100) is configured so that the clearance between the wall (105)
and the internal separator (130) is filled along at least one
radius (110).
Inventors: |
Moreau; Laurent;
(Versailles, FR) ; Bauerheim; Alain;
(Jonchery-sur-Vesle, FR) ; Metayer; Philippe;
(Voisins-le-Bretonneux, FR) ; Naudin; Yoann;
(Saint Loup en Champagne, FR) ; Gahon; Kevin;
(Bourgogne, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Moreau; Laurent
Bauerheim; Alain
Metayer; Philippe
Naudin; Yoann
Gahon; Kevin |
Versailles
Jonchery-sur-Vesle
Voisins-le-Bretonneux
Saint Loup en Champagne
Bourgogne |
|
FR
FR
FR
FR
FR |
|
|
Assignee: |
VALEO SYSTEMES THERMIQUES
Le Mesnil-Saint-Denis
FR
|
Family ID: |
43757841 |
Appl. No.: |
13/807478 |
Filed: |
June 14, 2011 |
PCT Filed: |
June 14, 2011 |
PCT NO: |
PCT/EP2011/059825 |
371 Date: |
April 18, 2013 |
Current U.S.
Class: |
165/177 ;
29/890.045 |
Current CPC
Class: |
B23P 15/26 20130101;
F28D 1/0391 20130101; F28F 1/40 20130101; F28F 13/12 20130101; F28F
3/12 20130101; F28F 3/025 20130101; Y10T 29/49377 20150115; B21C
37/225 20130101; F28F 1/022 20130101; B21D 53/06 20130101 |
Class at
Publication: |
165/177 ;
29/890.045 |
International
Class: |
F28F 1/02 20060101
F28F001/02; B21D 53/06 20060101 B21D053/06; F28F 1/40 20060101
F28F001/40 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2010 |
FR |
FR 1002767 |
Jun 30, 2010 |
FR |
FR 1002773 |
Dec 2, 2010 |
FR |
FR 1060044 |
Claims
1. A heat exchanger tube comprising a bent wall defining a housing
and an internal separator inserted into said housing, said internal
separator defining a plurality of fluid circulation channels and
said wall having large surfaces connected by radii, wherein the
tube is configured so that the clearance between the wall and the
internal separator is filled along the length of at least one
radius.
2. The tube as claimed in claim 1, wherein the internal separator
is corrugated and includes at least one flat at one apex, said flat
being in contact with the wall.
3. The tube as claimed in claim 1, wherein the internal separator
is corrugated and has a flat at each of its vertices, said flat
being in contact with the wall.
4. The tube as claimed in claim 1, wherein said tube is configured
so that the clearance between the wall and the internal separator
is filled along each radius.
5. The tube as claimed in claim 1, wherein said tube has a section
in the shape of a B and said wall includes legs that meet at a
central portion of said B-shaped section, at least one of said legs
being in contact with the internal separator.
6. A heat exchanger including at least one tube as claimed in claim
1.
7. A method of producing a heat exchanger tube, said tube
comprising a bent wall defining a housing and an internal separator
inserted into said housing, said internal separator defining a
plurality of fluid circulation channels and said wall having large
surfaces of length L connected by radii of height H, said method
comprising the steps of: inserting an internal separator in the
housing of the tube with a clearance; and compressing the tube in
the direction of its height, said compression compressing the tube
from a height H1 to a height H2 with H2<H1 and from a length L1
to a length L2 with L1<L2, the tube being configured after
compression so that the clearance between the wall and the internal
separator is at least partially filled.
8. The method as claimed in claim 7, including a preliminary step
wherein the wall of the tube is produced by bending a sheet of
material, said wall having, after bending, a substantially closed
section in which the internal separator is inserted.
9. The method as claimed in claim 7, wherein the compression is
exerted in a direction substantially orthogonal to the plane faces
of the tube.
10. A method of producing a heat exchanger tube, said tube
comprising a bent wall defining a housing and an internal separator
inserted into said housing, said internal separator defining a
plurality of fluid circulation channels and said wall having large
surfaces of length L connected by radii of height H, said method
comprising the steps of: inserting an internal separator in the
housing of the tube with a clearance; and compressing the tube in
the direction of its height, said compression compressing the tube
from a height H1 to a height H2 with H2<H1 and from a length L1
to a length L2 with L1<L2, the tube being configured after
compression so that the clearance between the wall and the internal
separator is at least partially filled, wherein the compression
step is such that the tube and its components, wall or internal
separator, have the features as claimed in claim 1.
11. The tube as claimed in claim 1, wherein the tube is part of a
condenser of a motor vehicle air conditioning system.
12. The heat exchanger as claimed in claim 6, wherein the heat
exchanger is a condenser of a motor vehicle air conditioning
system.
13. The tube as claimed in claim 2, wherein said tube is configured
so that the clearance between the wall and the internal separator
is filled along each radius.
14. The tube as claimed in claim 3, wherein said tube is configured
so that the clearance between the wall and the internal separator
is filled along each radius.
15. The method as claimed in claim 8, wherein the compression is
exerted in a direction substantially orthogonal to the plane faces
of the tube.
Description
[0001] The present invention concerns a heat exchanger tube, a heat
exchanger including such tubes and a method of producing such a
tube.
[0002] Be it non-exclusively, the heat exchangers concerned are
intended for equipping vehicles and, in a preferred application,
correspond to the condensers provided in the air conditioning loops
or circuits of the vehicles. There may nevertheless be envisaged,
without departing from the scope of the invention, an application
of these exchangers as radiators in engine cooling loops or
circuits.
[0003] Briefly, the air conditioning loop of the passenger
compartment of a vehicle generally consists primarily, in the
direction of flow of the coolant fluid (for example freon,
CO.sub.2, 1234YF fluid) passing through it, a compressor
compressing the fluid at this point in the form of vapor, a
condenser receiving the fluid to convert it to liquid form thanks
to a flow of external air sweeping it, an expander reducing the
pressure and an evaporator, in which the expanded and condensed
fluid exchanges heat with a flow of external air to be directed
into the passenger compartment. The fluid is converted to the vapor
phase at the outlet of the evaporator to be fed into the compressor
for a new cycle, while the flow of external air passing through the
evaporator is cooled to supply conditioned air in the passenger
compartment.
[0004] In structural terms, the condenser forming the heat
exchanger includes a bundle of parallel tubes and two manifolds (or
collector boxes) into which the corresponding ends of the tubes are
fixedly connected in sealed manner, by brazing them. Accordingly,
the coolant fluid in the loop is able to flow through the tubes,
the fluid being converted from its vapor phase to its liquid phase
by the flow of external air sweeping the tubes.
[0005] Two technologies are primarily used to manufacture these
tubes before assembly with the manifolds. Either extrusion,
generating a high cost (dedicated dies for each type of tube) but
easily brazable because naturally sealed, or bending, offering
various advantages, but more difficult to braze.
[0006] The invention relates to heat exchanger tubes produced using
the bending technology.
[0007] Such tubes are generally produced from a spool of sheet
metal which, after it is paid out in strip form, is progressively
shaped to the required cross section by dedicated bending tools or
the like, and then cut to the required length, in sections
corresponding to the finished tubes.
[0008] This being the case, the heat exchanger tubes may be
subjected to numerous loads such as a high-speed impact with an
object (for example a stone) from the exterior environment. The
tube must be able to withstand any such impact so as to prevent any
leaking of fluid. In the case of a bent tube, the tube cannot be
reinforced by an increased thickness of material as is the case for
an extruded tube. It is however necessary to increase the thickness
of the wall of the bent tube locally as the latter thickness is
generally around 0.2 mm, which is insufficient from the point of
view of withstanding stone impacts.
[0009] In a first known bent tube, the wall of the tube is bent
horizontally on itself several times at the level of one side or
nose of the tube, increasing the thickness of material in the tube
nose. A drawback is that the height of the tube is thus a function
of the thickness of material thereof and corresponds to the number
of bends.
[0010] In another known bent tube, the tube is open beforehand
along one of its sides that is then closed by overlapping plane on
plane two thicknesses of wall. A drawback of a solution of this
kind is the risk of defective sealing at the level of the side
closed in this way.
[0011] The patent DE102006006670 describes a solution including
sides having numerous vertical bends. A major drawback of this
solution is that it leads to excess consumption of material.
[0012] The patent U.S. Pat. No. 6,192,977 describes a tube one end
of which is constituted by the overlapping of the wall of the tube.
This solution is difficult to control in the case of tubes of low
height, for example of the order of 1 mm.
[0013] Furthermore, there are also known, notably from the patent
DE102005043093, tubes with an internal separator. With a tube and
an internal separator, it is not possible to proceed to cut the
tube and the internal separator to length with conventional means
(for example cutting with a knife), because the internal separator
tends to be compressed during this operation. In this case, the
tube is first shaped and then cut to length, the internal separator
is also shaped and then cut to length, and the tube and the
internal separator are then assembled. In this configuration it is
necessary to leave a functional clearance between the tube and the
internal separator to be able to insert the latter. This clearance
is not favorable for correct brazing of the components to each
other.
[0014] In the existing solutions, the contacts between the internal
separator and the walls of the tube necessary for increasing the
mechanical strength are not necessarily guaranteed. Moreover, in
the existing solutions, the problem of stone impact remains.
[0015] An object of the present invention is to remedy these
drawbacks and the present invention concerns a fluid circulation
tube the design of which enables the internal separator to
reinforce the tube and notably at least one side of the tube.
[0016] To this end, the heat exchanger tube comprises a bent wall
defining a housing and an internal, for example corrugated,
separator inserted into the housing. The internal separator defines
a plurality of fluid circulation channels. The wall of the tube has
large surfaces connected by radii. The internal separator extends
in the lengthwise direction, for example, from one orifice to the
other of the tube. The large surfaces are notably plane and
parallel to each other.
[0017] According to the invention, the tube is configured so that
the clearance between the wall and the internal separator is filled
along the length of at least one radius. In other words,
considering the tube in cross section, i.e. in a section plane
orthogonal to its longitudinal axis, the clearance between the
internal separator and the wall of the tube is filled along the
radius, over all or part of the length of the internal separator.
The effect of this is to increase the overall area of contact
between the separator and the walls of the tube, and therefore the
thickness of the tube, at least at the level of the nose of the
tube.
[0018] According to one aspect of the present invention, the
internal separator includes at least one flat at one apex, said
flat being in contact with the wall. This has the advantage of
increasing the mechanical strength, including at the level of its
plane faces.
[0019] According to one aspect of the present invention, the
internal separator includes a flat at each of its vertices, said
flat being in contact with the wall.
[0020] According to one aspect of the present invention, the tube
is configured so that the clearance between the wall and the
internal separator is filled along each radius. This has the
advantage of reinforcing the tube noses on each side of the tube
and thus avoiding the necessity to mark the reinforced side.
[0021] According to one aspect of the present invention, the tube
has a section in the shape of a B and said wall comprises legs that
meet at the level of a central portion of said B-shaped section. At
least one of said legs is in contact with the internal separator.
This has the advantage of increasing the mechanical strength of the
tube.
[0022] It is to be noted that, according to the invention, these
various features are encountered both in a tube once brazed and in
a tube not yet brazed.
[0023] The invention also concerns a heat exchanger that includes
tubes as defined above. The heat exchanger with these fluid
circulation tubes preferably defines the condenser of a motor
vehicle air conditioning loop or the like. As indicated above, such
a heat exchanger finds a particular application in the field of
motor vehicles, for example to produce an air conditioning
condenser.
[0024] The exchanger has the structure referred to above, for
example.
[0025] The invention also concerns a method of producing a heat
exchanger tube, in particular the condenser of a motor vehicle air
conditioning system. The tube comprises a bent wall defining a
housing and an internal separator, which is for example corrugated,
inserted into the housing with a clearance. The internal separator
defines a plurality of fluid circulation channels and the wall of
the tube has large surfaces, notably plane surfaces, of length L
connected by radii of height H. The method comprises the steps of
inserting the internal separator in the housing and compressing the
tube in the direction of its height. According to the invention the
compression is characterized in that it compresses the tube from a
height H1 to a height H2 with H2<H1 and from a length L1 to a
length L2 with L1<L2, so that the clearance between the wall and
the internal separator is at least partially filled.
[0026] By compressing the tube from a height H1 to a height H2 with
H2<H1 and from a length L1 to a length L2 with L1<L2, the
compression enables the overall area of contact between the insert
and the walls of the tube to be increased, notably at the level of
at least one tube nose. This has the advantage of enabling better
brazing between the internal separator and the walls of the tube in
contact with the internal separator. Another advantage of the
method of the invention is that the compression (i.e. deformation)
enables linear and homogeneous reshaping of the tube including the
internal separator.
[0027] According to one aspect of the present invention, the method
includes a preliminary step wherein the wall of the tube is
produced by bending a sheet of material, for example, and has,
after bending, a substantially closed section in which the internal
separator is inserted.
[0028] According to one aspect of the present invention, during the
compression step of the method, the compression is exerted in a
direction substantially orthogonal to the plane faces of the
tube.
[0029] According to one aspect of the present invention, the
compression step is configured so that the tube and its components,
wall and/or insert, have the features referred to above.
[0030] The appended figures explain how the invention may be
reduced to practice. In these figures, identical references design
similar elements.
[0031] FIG. 1A represents a tube bent into the shape of a B before
compression in accordance with one embodiment of the invention and
including an internal separator inserted between the walls of the
tube.
[0032] FIG. 1B represents the tube from FIG. 1A after
compression.
[0033] As shown in FIG. 1A and 1B and in accordance with the
invention, a heat exchanger tube 100, notably of an air
conditioning condenser for motor vehicles, comprises a bent wall
105, defining a housing 115, and an internal separator 130,
inserted in the housing. The internal separator 130, which is
notably corrugated, defines a plurality of fluid circulation
channels 136. The wall 105 has large, for example plane, surfaces
connected by radii 110. The wall of the tube notably has a cross
section in the shape of a B.
[0034] In other words, in the example shown, once the tubes have
been bent and then cut into sections, their thin wall has a cross
section in the overall shape of a flattened B, i.e. with a base
part extended laterally, by way of two connecting parts, by two
coplanar, facing top parts parallel to the base part that terminate
in adjacent end legs, facing perpendicularly toward the base part,
and separated from the latter. Two longitudinal and parallel
internal spaces or channels, corresponding to the loops of the B,
are then defined in which are inserted, to their full length and in
known manner, the two arrays of bends of an internal separator or
disturber that are interconnected by a plane connecting part
inserted in the space left between the end legs and the base part
of the bent wall of the tube.
[0035] This inner spacer or each of these inner spacers notably
also has the function of improving the thermal performance of the
condenser and the mechanical strength of the tubes, which must
resist not only the operating pressure when the loop is operating,
which is of the order of 20 bar, but also that imposed by the
specification, notably a tube bursting rating of up to 100 bar, for
coolant fluids based on freon. Clearly, after the pre-assembled
condenser (tubes, with internal separators, nested in the
manifolds) is placed in a brazing furnace notably enabling
fastening of the vertices of the longitudinal and corrugated bends
of each internal separator to the internal face of the wall bent
into the shape of a B of each tube, thanks to cladding provided on
them (on the internal separator and/or on the wall of the tube) and
the melting point of which is slightly lower than that of the
material constituting the wall of the tubes and internal separators
(for example aluminum alloy).
[0036] According to the invention, the tube 100 is configured so
that the clearance is filled along at least one radius 110 between
the wall 105 and the internal separator 130. The clearance is
defined by the space that exists between the internal radius of the
radius 110 of the tube 100 and the curvature of the end 134 of the
internal separator 130. This means that the contact is continuous
so that the clearance between the wall 105 and the internal
separator 130 is entirely filled over all the length of the radius
(i.e. along all the curvature of the radius). The tube is
configured so that the clearance between the wall 105 and the
internal separator 130 is for example filled along each radius
110.
[0037] In the embodiment shown, the internal separator 130 includes
at least one flat at a vertex 132, notably at each vertex 132, said
flat being in contact with the wall.
[0038] As already stated, the tube 100 has, for example, a section
in the shape of a B and the wall has legs 120 joined at the level
of the central part of said B-shaped section, at least one of the
legs 120 being in contact with the internal separator 130.
[0039] The invention further concerns a method of producing a heat
exchanger tube, notably for motor vehicle air conditioning system
condensers. According to the invention, the tube 100 comprises a
wall 105 defining a housing 115 and an internal separator 130
inserted in the housing 115. The internal separator 130 defines a
plurality of fluid circulation channels 136. The wall has large,
notably plane, faces of length L connected by radii of height H. As
shown in FIGS. 1A and 1B, the length L corresponds to the dimension
of the tube 100 in the direction of its longitudinal section. As
shown in FIGS. 1A and 1B, the height H corresponds to the overall
thickness of the tube 100, i.e. its thickness in the direction of
its cross section. Of course, although this is not represented, the
tube extends along its longitudinal axis, orthogonal to the plane
of FIGS. 1A and 1B.
[0040] The method of the invention includes a first step in which
the internal separator 130 is inserted into the housing 115 of the
tube 100 with a clearance.
[0041] The method of the invention includes a second step in which
the tube 100 is compressed in the direction of the height H. This
compression is characterized in that it enables the tube to be
compressed from a height H1 to a height H2 with H2<H1 and from a
length L1 to a length L2 with L1<L2, the tube 100 being
configured after compression so that the clearance between the wall
105 and the internal separator 130 is at least partially
filled.
[0042] The compression step may be generalized to a deformation
step without limiting the scope of the protection of the present
invention.
[0043] The compression or deformation step enables the wall 105 and
the internal separator 130 to be calibrated. This step enables
reshaping of the tube 100, the dimensions of which are modified.
Before reshaping, there exists a clearance in the direction of the
height H and also in the direction of the length L that enables the
insertion of the internal separator 130. The dimensions of the wall
105 and the internal separator 130 can be defined beforehand so
that this clearance exists despite the manufacturing tolerances of
the two parts. A reshaping dimension is then defined in order to
calibrate the tube 100 and the internal separator 130 and to fill
at least one clearance or even all of the clearances provided for
the purpose of this insertion.
[0044] The compression step enables the height H to be reduced and
the length L to be increased. The effect of this is to fill the
clearance along the radius between the wall 105 and the internal
separator 130 and to enable brazing of the components. By virtue of
their design, the increase in the dimension L of the wall 105 will
be less than that of the internal separator 130.
[0045] In other words, the compression step makes it possible to
increase the length dimension L of the internal separator 130 more
than that of the wall 105. This makes it possible to fill the
assembly clearance between the internal separator 130 and the
inside radius of the tube nose 110. This moreover makes possible
the brazing of the two components (i.e. wall 105 and internal
separator 130) and thus to increase the mechanical strength,
notably at the level of the tube nose 110.
[0046] The method could include a preliminary step in which the
wall of the tube is produced by bending a sheet of material, for
example, and after bending has a substantially closed section into
which the internal separator is inserted.
[0047] In one embodiment, during the compression step of the
method, the compression is exerted in a direction substantially
orthogonal to the plane faces of the tube.
[0048] The compression step is configured so that the tube and its
components, wall and/or internal separator, have the features
referred to above, for example.
[0049] To be more precise, the compression step could be configured
so that, after compression, the internal separator 130 includes a
flat at one at least of its vertices 136, said flat being in
contact with the wall.
[0050] The compression step thus enables the production of the
plane areas at some or all of the vertices 136 of the internal
separator 130. In other words, the consequences of the reduction in
the height are crushing of the internal separator 130 generating a
flat at its vertex and, depending on the magnitude of the
calibration, modifying the angles of the bends of the internal
separator 130. The effect of this is to guarantee the brazing
between the internal wall of the wall 105 and the internal
separator insert 130 as well as to increase the mechanical strength
of this combination.
[0051] The compression step could also be configured so that the
clearance between the wall 105 and the internal separator 130 is
filled along each radius 110.
[0052] The compression step could further be configured so that,
after compression, at least one of said legs 120 is in contact with
the internal separator 130.
* * * * *