U.S. patent application number 12/243628 was filed with the patent office on 2009-05-21 for heat exchanger and method for its production.
This patent application is currently assigned to BEHR GmbH & CO.KG. Invention is credited to Thomas BENSEL, Werner Helms, Oliver Liedtke.
Application Number | 20090126919 12/243628 |
Document ID | / |
Family ID | 40418059 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090126919 |
Kind Code |
A1 |
BENSEL; Thomas ; et
al. |
May 21, 2009 |
HEAT EXCHANGER AND METHOD FOR ITS PRODUCTION
Abstract
The invention relates to a heat exchanger having a multiplicity
of heat-exchanger tubes in which a fluid, such as a coolant, can
flow, and whose ends are held in collecting tanks. At least two
collecting volumes which are separated from one another by an
insert are arranged at least in one collecting tank. A separating
cut which separates the insert and therefore also the collecting
tank is formed in the heat exchanger.
Inventors: |
BENSEL; Thomas; (Ditzingen,
DE) ; Helms; Werner; (Esslingen, DE) ;
Liedtke; Oliver; (Karlsruhe, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmbH & CO.KG
|
Family ID: |
40418059 |
Appl. No.: |
12/243628 |
Filed: |
October 1, 2008 |
Current U.S.
Class: |
165/173 ;
29/890.03 |
Current CPC
Class: |
F28F 9/0212 20130101;
F28D 2021/0094 20130101; Y10T 29/4935 20150115; F28D 1/05391
20130101; B23P 15/26 20130101 |
Class at
Publication: |
165/173 ;
29/890.03 |
International
Class: |
F28F 9/00 20060101
F28F009/00; B21D 53/02 20060101 B21D053/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 2, 2007 |
DE |
10 2007 047 294.5 |
Claims
1. Heat exchanger having a multiplicity of heat-exchanger tubes in
which a fluid, such as a coolant, can flow, and whose ends are held
in collecting tanks, with at least two collecting volumes which are
separated from one another by an insert being arranged at least in
one collecting tank, wherein in that a separating cut which
separates the collecting tank is formed in the insert.
2. Heat exchanger according to claim 1, wherein the two parts of
the insert form outer walls of two collecting tanks.
3. Heat exchanger according to claim 1, wherein the insert is
sealingly connected along its periphery to the collecting tank.
4. Heat exchanger according to claim 1, wherein the insert is a
solid separating element.
5. Heat exchanger according to claim 1, wherein the insert has a
recess in the region of the intended separating process.
6. Heat exchanger according to claim 1, wherein the insert
comprises a heat-exchanging tube which is separated along its
longitudinal axis by the separating process.
7. Heat exchanger according to claim 6, wherein the heat-exchanging
tube which is comprised by the insert is composed of the same
semifinished part as a heat-exchanging tube which is traversed by
coolant.
8. Heat exchanger according to claim 6, wherein the heat-exchanging
tube serves as a connecting element between two heat-exchanging
units.
9. Heat exchanger according to one of claims 1, wherein the insert
comprises two metal sheets.
10. Heat exchanger according to claim 1, wherein the separating cut
does not extend as far as an opposite collecting tank.
11. Heat exchanger according to claim 10, wherein the separating
cut has a length in the range from 10 to 75%, in particular in the
range from 10 to 50% and very particularly a length in the range
from 10 to 25% of the heat-exchanging unit.
12. Heat exchanger according to claim 1, wherein at least one
separating cut is also formed in a second collecting tank.
13. Method for producing a heat exchanger according to claim 1,
having the following method steps: arranging the heat-exchanging
tubes, the collecting tanks and the insert of the heat exchanger,
joining said elements, separating at least one collecting tank in
the region of the insert.
14. Method according to claim 13, wherein during the arrangement of
the elements of the heat exchanger, a heat-exchanging tube or metal
sheet is held in the insert, which heat-exchanging tube or metal
sheet is substantially the same length as or longer than a
heat-exchanging tube which is traversed by the fluid, such as
coolant.
15. Method according to claim 13, wherein the insert is inserted
into the water tank before or after the arrangement of the
heat-exchanging tubes.
16. Method according to claim 13, wherein the separation of the
water tanks takes place before or after the joining of the heat
exchanger.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The right of foreign priority is claimed under 35 U.S.C.
.sctn. 119(a) based on Federal Republic of Germany Application No.
10 2007 047 294.5, filed Oct. 2, 2007, the entire contents of
which, including the specification, drawings, claims and abstract,
are incorporated herein by reference.
BACKGROUND
[0002] The invention relates to a heat exchanger, in particular for
cooling a coolant, preferably in a motor vehicle, which heat
exchanger has a multiplicity of heat-exchanger tubes in which
coolant can flow, and whose ends are held in collecting tanks. At
least two collecting volumes which are separated from one another
by an insert are arranged in at least one collecting tank.
[0003] A heat exchanger of the stated type is known for example
from EP 1 410 929. Hot water is conducted from an engine into a
first collecting volume of a collecting tank, flows through the
heat-exchanging tubes, changes its flow direction in a second
collecting tank and is conducted through heat-exchanging tubes into
a second collecting volume of the first collecting tank. As it
flows through the heat-exchanger tubes, the hot water heats the air
which flows transversely through the heat exchanger. Situated
between the two collecting volumes of the first collecting tank is
a partition which separates the two collecting volumes.
[0004] The water at the two sides of the partition has a different
temperature as a result of the cooling as it passes through the
heat-exchanger tubes, with the difference between the two
temperatures varying with the heating temperature set by the motor
vehicle occupants.
[0005] If use is made, for example, of coolant coolers with
relatively long tubes and a partition in one collecting tank, then
thermal loading which is generated on account of a temperature
difference can generate stresses in the region of the partition of
the heat exchanger. Said stresses may cause damage, such as for
example fracture points in the collecting tank wall in the region
of the partitions, and thereby lead to a limited durability of
collecting tanks of said type or of the heat exchanger.
[0006] To prevent damage by thermal loading, it is proposed in DE 3
927 955 to produce water tanks from plastic in order to obtain
thermal decoupling. In DE 3 540 415, to prevent an exchange of heat
between two collecting volumes, it is proposed to join together two
in each case complete, separate heat exchangers to form a double
heat exchanger. Here, the two heat exchangers bear against one
another at the fluid inlet, such as coolant inlet. The two
collecting tanks between which there is a temperature difference
are arranged spaced apart from one another.
[0007] DE 44 01 859 discloses a double cross-flow heat exchanger in
which the coolant is supplied and discharged at the two sides of
the heat exchanger. After passing in each case once through the
heat-exchanger tubes, the two coolant flows converge, with a small
temperature difference, at the partition which is arranged
centrally in the heat exchanger, resulting in relatively low
stresses in the partition region. The required tube arrangement for
the two sides of the heat exchanger, however, requires increased
expenditure in the heat exchanger and during installation into a
motor vehicle.
[0008] It is also known to provide additional reinforcement
elements such as for example metal sheets in the partition region
of the collecting tank in order to absorb the stresses generated by
the temperature difference. The insertion of such metal sheets has
proven firstly to be complex and secondly to be insufficient with
regard to relatively high thermal-cycle loading.
SUMMARY OF PREFERRED EMBODIMENTS
[0009] It is the object of the present invention to create a heat
exchanger which has a simple design with thermal decoupling of
adjacent collecting tanks. Furthermore, it is intended to specify a
method which permits simple and cost-effective production of said
heat exchanger.
[0010] Said object is achieved according to the invention by means
of the subject matter of Claim 1. The method according to the
invention for producing the heat exchanger is the subject matter of
Claim 13. Advantageous refinements are the subject matter of the
subclaims.
[0011] To achieve said object, a heat exchanger is proposed which
has a multiplicity of heat-exchanger tubes in which coolant can
flow, and whose ends at the two sides are held in collecting tanks.
At least two collecting volumes which are separated from one
another by an insert are arranged at least in one collecting tank.
The insert is separated into two parts by a continuous separating
cut which separates the collecting tank.
[0012] In one preferred embodiment of the present invention, the
heat exchanger has a multiplicity of preferably rectangular
heat-exchanging tubes, between which are preferably arranged
heat-exchanging devices such as lamellae which preferably bear at
both sides in a heat-conducting manner against in each case one
heat-exchanging tube in order to ensure a good exchange of heat
between the heat-exchanging tubes and the lamellae, and thereby to
obtain a high cooling capacity. The two axial ends of the
heat-exchanging tubes open out into collecting tanks which are
arranged there and in which the heat-exchanging tubes are held in
an individually sealingly enclosed fashion.
[0013] At least one of the collecting tanks has a partition which,
according to the invention, is formed by the insert in the
collecting tank, which insert is fixedly connected to the
collecting tank. As a result of a separating process, the insert
according to the invention and therefore the collecting tank is
separated into two parts, such that the parts of the insert form in
each case one outer wall of two independent collecting volumes.
[0014] For the separation, the insert according to the invention is
preferably inserted into the collecting tank in such a way that
said insert is sealingly connected along its periphery at both
opposite sides to the collecting tank. Here, the insert may be
composed of a solid separating element. The insert preferably has a
recess in the region of the intended separating process, which
recess serves to control and shorten the separating process.
[0015] The insert is preferably designed so as to hold a
heat-exchanging tube which is separated along its longitudinal axis
by the separating process. In this case, it is possible to maintain
the construction of the heat-exchanging unit of the heat exchanger
from alternately arranged heat-exchanging tubes and lamellae. In
this design, it is also advantageous that the lamellae at both
sides of the separating cut are still supported. Furthermore, on
account of the small wall thickness, only a low level of separating
energy is required for separating a heat-exchanging tube along its
longitudinal axis. Furthermore, by using the same heat-exchanging
tubes in the insert and for exchanging heat, the construction of
the heat exchanger can be substantially maintained, and the
preparation for production can be simplified.
[0016] It is however also possible for two metal sheets, which
preferably correspond to the shape of a heat-exchanging tube, to be
provided in the insert instead of a heat-exchanging tube. In this
embodiment, the separating process is complete after the process of
cutting through the insert with the collecting tank. The separation
of the two heat-exchanging units of the heat exchanger extends here
up to the point at which the metal sheets are held in the
collecting tank on the opposite side of the heat exchanger.
[0017] As a result of the separation of a first collecting tank in
the region of the insert, a first heat-exchanging unit is generated
which is preferably connected at one side to a first separate
collecting tank, which forms a first collecting volume, and a
second heat-exchanging unit, which is preferably connected at one
side to a second separate collecting tank, which forms a second
collecting volume. Now, in a heat exchanger which is designed in
this way, if a coolant at a high temperature is conducted into the
first collecting tank, said coolant flows through the
heat-exchanging tubes of the first heat-exchanging unit, changes
its direction in the second collecting tank on the opposite side of
the heat-exchanging tubes, and flows through the heat-exchanging
tubes of the second heat-exchanging unit, which heat-exchanging
tubes are connected to the second separate collecting tank, into
said second separate collecting tank.
[0018] While the coolant flows through the heat-exchanging tubes,
it heats said tubes and also the interposed lamellae. The heat
energy is dissipated from there to the air flowing through the heat
exchanger. Here, the coolant in the heat-exchanging tubes is
cooled. A temperature difference is thus generated between the
coolant in the first and second separate collecting tanks. The
separation of the two adjacent collecting tanks allows the two
heat-exchanging units to expand and move independently. As a result
of the temperature difference, therefore, no stresses arising from
the heat-exchanging units are generated either which could lead to
damage of the collecting tanks.
[0019] The depth of the separating cut in the heat-exchanging
region also influences the stability of the heat exchanger. In one
preferred embodiment, it is therefore provided that the insert
comprises a connecting element, for example a heat-exchanging tube
which is not traversed by coolant. Depending on the expected
temperature difference, the separating cut, preferably in the
connecting element, preferably does not extend as far as the
opposite collecting tank, such that a high level of stiffness of
the heat exchanger is maintained. Here, an independent movement of
the two collecting tanks generated by the separation, and a
prevention of the exchange of heat between the two partition
surfaces, is restricted only to the extent required on account of
the thermal loading of the heat exchanger. Here, a separation
length of the heat-exchanging unit in the range from 10 to 75%, in
particular in the range from 10 to 50% and very particularly in the
range from 10 to 25% has proven to be particularly expedient. This
constitutes an optimum compromise between sufficient thermal
independence of the two regions and the stability of the heat
exchanger.
[0020] In a further embodiment of the heat exchanger according to
the invention, a separation according to the invention is also
formed in a second collecting tank which, as a result of the
coolant guidance, comprises two collecting volumes. In this
embodiment, too, the stability of the heat exchanger is dependent
on the length of the separation of the heat-exchanging units in the
direction of the opposite collecting tank. On account of the
possibility for separating the collecting tanks between two
collecting volumes, it is also made possible to provide a
simplified configuration of the flow of coolant through a heat
exchanger.
[0021] A method according to the invention for producing a heat
exchanger of the above-described type comprises substantially three
method steps: arranging elements of the heat exchanger, joining
said elements, and separating at least one collecting tank in the
region of an insert. It is likewise possible to separate the water
tank(s) in the region of inserts before the joining of the heat
exchanger, and to subsequently join the water tanks produced to the
further elements of the heat exchanger, or preferably, to join the
elements of the heat exchanger and subsequently separate the water
tanks.
[0022] The method according to the invention for producing the heat
exchanger is described by way of example using an insert which
comprises a heat-exchanging tube which is not traversed by coolant.
When using other inserts according to the invention, a method is
used which corresponds to the production steps described.
Furthermore, the method for producing a heat exchanger is described
with only one separation of a collecting tank. Further separating
processes may take place corresponding to the approach for carrying
out the described separating process.
[0023] In a first step, a grouping of a heat-exchanging unit, which
is in one piece at this time, preferably takes place. At the
position of the later separation of the collecting tank, the
heat-exchanging unit comprises a heat-exchanging tube with a
substantially equal or greater length. A tube of said type may for
example be offset or displaced with respect to the partition. The
receptacle of the tube may be omitted in a base without a partition
or in a region of the base without a partition, such that said tube
is not traversed by coolant. The grouped heat-exchanging unit
preferably comprises the heat-exchanging tubes, the side parts and
lamellae which are inserted between said elements. In a compressed,
aligned state of said heat-exchanging unit, a heat-exchanging tube
which is to be held in the insert projects beyond the other parts
of the heat-exchanging unit. The heat-exchanging unit is joined at
both sides to the corresponding elements of the water tanks. Here,
the heat-exchanging tube of greater length is preferably held in
the insert according to the invention, which later forms the two
side walls of the separated collecting volumes. It is also possible
to retroactively place the insert onto the respective
heat-exchanging tubes. Depending on the assembly sequence, further
elements of the collecting tanks including the heat-exchanger
connections are now arranged.
[0024] The joining of the individual elements of the heat exchanger
preferably follows in the next step. Soldering is used as the
preferred joining process. It is however also possible to connect
the elements of the heat exchanger by means of some other suitable
joining process, such as for example by adhesive bonding or
welding.
[0025] The separation of the collecting tank into two independent
collecting volumes in the plane defined by the position of the
insert, which is fixedly connected to the collecting tube,
preferably takes place after the joining process. The length of the
formed separating cut, which is preferably formed by sawing, is
dependent on the requirement for preventing the exchange of heat
between the separated collecting tanks and on the required strength
of the heat exchanger or the required mobility of the collecting
tanks with respect to one another.
[0026] Depending on the joining process which is used and the
desired depth of the separating cut, it is also possible for the
water tanks to be separated, according to the invention, before the
joining of the heat exchanger.
[0027] An advantage of an insert which comprises a separating tube
or metal sheets is that said elements support the two
heat-exchanging units, and in particular lamellae which bear
against these, both during the separating process and also in the
heat exchanger produced in this way, and thus reinforce said heat
exchanger and enlarge the heat-exchanging surface. When using a
heat-exchanging tube, it is possible, as already described, to use
the same semifinished part as for the heat-exchanging tubes which
are traversed by coolant. In this way, the bundling process is
advantageously virtually unchanged in relation to that of a heat
exchanger from the prior art. The mechanical separation of the
collecting tank results in thermal decoupling which leads to a
considerably increased level of durability, in particular under
alternating or varying thermal loading.
[0028] Further objects, features and advantages of the present
invention will become apparent from the detailed description of
preferred embodiments that follows, when considered together with
the accompanying figures of drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Further advantages, features and possible applications of
the present invention can be gathered from the following
description in connection with the figures, in which:
[0030] FIG. 1 shows a heat exchanger according to one embodiment of
the present invention;
[0031] FIG. 2 shows an enlarged, partially sectioned view of a
collecting tank with a partition before the separation; and
[0032] FIG. 3 shows an enlarged, sectioned view of the partition of
the collecting tank before the separation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] FIG. 1 shows a heat exchanger 10 according to one embodiment
of the present invention. The heat exchanger 10 comprises three
collecting tanks 11, 12, 13 with coolant connections 21, 22 and 23
respectively. Furthermore, the heat exchanger comprises two
heat-exchanging units 31 and 32. These heat-exchanging units are
composed of heat-exchanging tubes 33, lamellae 34 and side parts
35.
[0034] The collecting tanks 12 and 13 and the two heat-exchanging
units 31 and 32 have been formed by a separating cut 40 which
divides elements of the previously unseparated heat exchanger.
[0035] The heat exchanger 10 illustrated in FIG. 1 functions as
follows: coolant, in this case cooling water of an internal
combustion engine, passes through the connection 22 into the
collecting tank 12. The hot water then flows through the
heat-exchanging tubes 33 of the heat-exchanging unit 31 and
collects in the collecting tank 11. Depending on the configuration
of the connections 21, 22 and 23, the hot water can flow through
the whole of the heat exchanger 10 or partially, leaving the heat
exchanger 10 again through the connection 21. In another
configuration variant, the water which has been slightly cooled
after flowing through the heat-exchanging unit 31 flows through the
heat-exchanging tubes 33 of the heat-exchanging unit 32 and then
collects in the water tank 13, which it leaves again through the
connection 23.
[0036] The heat-exchanging tubes 33 of the heat-exchanging unit 32
have only a small temperature difference with respect to the
heat-exchanging tubes 33 of the heat-exchanging unit 31 in the
region of the collecting tank 11, but have a considerably greater
temperature difference with respect to the heat-exchanging tubes 33
of the heat-exchanging unit 31 in the region of the collecting
tanks 12 and 13. The two collecting tanks 12 and 13 and the
adjoining heat-exchanging units 31 and 32 are thermally decoupled
by the separating cut 40 in the heat exchanger 10 and can move
substantially independently of one another.
[0037] FIG. 2 shows an enlarged, partially sectioned view of the
collecting tanks 12 and 13 during the production process, before
their separation. The heat-exchanging tubes 33 are not shown in the
illustration. The collecting tanks 12 and 13 have, at the side
facing toward the heat-exchanging unit, cutouts 14 which serve to
receive heat-exchanging tubes 33. At the position of the later
separating cut 40, an insert 42 is arranged in the water tank 12,
13, which insert 42 is sealingly soldered at the periphery 44 at
both sides to the water tank 12, 13. The insert 42 additionally
comprises a heat-exchanging tube 43 which is not provided for being
traversed by coolant and which serves as a connecting element in
the heat exchanger 10.
[0038] FIG. 3 shows an enlarged sectioned view of the partition of
the collecting tank 12, 13 before its separation. Here, the
receptacle of the insert 42 within the water tank is shown. The
connection between the periphery 44 of the insert 42 and the water
tank 12, 13 is not illustrated. The sectioned illustration shows
the separating plane of the later separating cut 40 which is
defined by the longitudinal axis of the heat-exchanging tube 43.
The heat-exchanging tube 43 is also fixedly connected at both sides
to the insert 42 in order to stabilize the separating process and
the sides, which are generated by the separation, of the
heat-exchanging units 31 and 32.
[0039] The foregoing description of preferred embodiments of the
invention has been presented for purposes of illustration and
description only. It is not intended to be exhaustive or to limit
the invention to the precise form disclosed, and modifications and
variations are possible and/or would be apparent in light of the
above teachings or may be acquired from practice of the invention.
The embodiments were chosen and described in order to explain the
principles of the invention and its practical application to enable
one skilled in the art to utilize the invention in various
embodiments and with various modifications as are suited to the
particular use contemplated. It is intended that the scope of the
invention be defined by the claims appended hereto and that the
claims encompass all embodiments of the invention, including the
disclosed embodiments and their equivalents.
* * * * *