U.S. patent application number 13/182939 was filed with the patent office on 2012-07-19 for heat exchanger.
This patent application is currently assigned to Benteler Automobiltechnik GmbH. Invention is credited to Thorsten Andres, Sven Przybylski.
Application Number | 20120180990 13/182939 |
Document ID | / |
Family ID | 45402830 |
Filed Date | 2012-07-19 |
United States Patent
Application |
20120180990 |
Kind Code |
A1 |
Przybylski; Sven ; et
al. |
July 19, 2012 |
HEAT EXCHANGER
Abstract
A heat exchanger includes at least two adjacent heat exchanging
tubes, each having equilateral triangular cross section. Hot gas
flows through the heat exchanging tubes and coolant flows over the
heat exchanging tubes. The heat exchanging tubes form a tube bundle
of polygonal cross section and have two tube walls arranged in
parallel side-by-side relation at a distance to one another.
Inventors: |
Przybylski; Sven;
(Paderborn, DE) ; Andres; Thorsten; (Paderborn,
DE) |
Assignee: |
Benteler Automobiltechnik
GmbH
Paderborn
DE
|
Family ID: |
45402830 |
Appl. No.: |
13/182939 |
Filed: |
July 14, 2011 |
Current U.S.
Class: |
165/104.14 |
Current CPC
Class: |
F28F 1/04 20130101; F28D
7/1684 20130101; F28F 2250/06 20130101; F28D 21/0003 20130101; F02M
26/32 20160201 |
Class at
Publication: |
165/104.14 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2010 |
DE |
10 2010 027338.4 |
Claims
1. A heat exchanger, comprising at least two adjacent heat
exchanging tubes, each having equilateral triangular cross section,
with hot gas flowing through the heat exchanging tubes and coolant
flowing over the heat exchanging tubes, said heat exchanging tubes
forming a tube bundle of polygonal cross section and having two
tube walls arranged in parallel side-by-side relation at a distance
to one another.
2. The heat exchanger of claim 1, wherein the heat exchanging tubes
are made of steel.
3. The heat exchanger of claim 1, wherein the coolant is cooling
water.
4. The heat exchanger of claim 1, further comprising a shell having
a rhombic cross section and ensheathing the heat exchanging tubes
at a distance thereto.
5. The heat exchanger of claim 4, wherein the shell is made of
steel.
6. The heat exchanger of claim 4, wherein the shell has inclined
walls, and further comprising bypass tubes extending laterally
adjacent to the inclined wails.
7. The heat exchanger of claim 6, further comprising a housing
having a rectangular cross section and ensheathing the tube bundle
and the bypass tubes.
8. The heat exchanger of claim 7, wherein the housing is made of
steel sheet.
9. The heat exchanger of claim 1, further comprising a shell having
a hexagonal cross section and ensheathing the heat exchanging tubes
at a distance thereto.
10. The heat exchanger of claim 9, wherein the shell is made of
steel.
11. The heat exchanger of claim 9, wherein the shell has inclined
walls, and further comprising bypass tubes extending laterally
adjacent to the inclined walls.
12. The heat exchanger of claim 11, further comprising a housing
having a rhombic cross section and ensheathing the tube bundle and
the bypass tubes.
13. The heat exchanger of claim 12, wherein the housing is made of
steel sheet.
14. The heat exchanger of claim 1, wherein the heat exchanging
tubes are provided with protuberances and/or grooves.
15. The heat exchanger of claim 14, wherein the protuberances
and/or grooves have a round, half-round, rhomboid, triangular, or
oval configuration.
16. The heat exchanger of claim 14, wherein the protuberances
and/or grooves extend in longitudinal direction of the heat
exchanging tubes or have a helical configuration.
17. The heat exchanger of claim 1, further comprising a turbulence
generator inserted in the heat exchanging tubes.
18. The heat exchanger of claim 1, further comprising a tube sheet
to combine the heat exchanging tubes to form the tube bundle.
19. The heat exchanger of claim 18, wherein the tube sheet is
constructed as a sheet metal water deflector.
20. The heat exchanger of claim 1, forming part of an exhaust gas
recirculation system for an internal combustion engine, wherein the
hot gas is exhaust gas of the internal combustion engine and the
coolant is cooling water.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent
Application, Serial No. 10 2010 027 338.4, filed Jul. 15, 2010,
pursuant to 35 U.S.C. 119(a)-(d), the content of which is
incorporated herein by reference in its entirety as if fully set
forth herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a heat exchanger.
[0003] It would be desirable and advantageous to provide an
improved heat exchanger to obviate prior art shortcomings.
SUMMARY OF THE INVENTION
[0004] According to one aspect of the present invention, a heat
exchanger includes at least two adjacent heat exchanging tubes,
each having equilateral triangular cross section, with hot gas
flowing through the heat exchanging tubes and coolant flowing over
the heat exchanging tubes, wherein the heat exchanging tubes form a
tube bundle of polygonal cross section and have two tube walls
arranged in parallel side-by-side relation at a distance to one
another.
[0005] As a result of the equilateral triangular cross section of
the heat exchanging tubes, a heat exchanger according to the
present invention exhibits a surface area which is about 1.3 times
larger than in a conventional heat exchanger of circular cross
section and same inner cross sectional area. The surface area of
the heat exchanging tubes of a heat exchanger according to the
present invention has maximum size and the heat exchanging tubes
require considerably less installation space. Thus, a heat
exchanger according to the present invention provides a comparably
large heat exchanging surface between hot gas flowing in the heat
exchanging tubes and the coolant sweeping over the heat exchanging
tubes. While the surface area, compared to round tubes, is thus
reduced by about a third, the cooling surface can be increased by
about a third. The distance between the triangular heat exchanging
tubes in the tube bundle can be varied to best utilize the cooling
effect in accordance with the throughflow direction of the coolant.
An example of coolant includes cooling water.
[0006] According to another advantageous feature of the present
invention, the heat exchanging tubes can be made of steel.
[0007] According to another advantageous feature of the present
invention, the heat exchanging tubes can be placed in such a way
that the tube bundle exhibits a rhombic configuration. Such a
disposition of the heat exchanging tubes results in an optimum
relationship between the tube surfaces and the volume defined
within the heat exchanging tubes. This manifests itself in
particular when two, four, six, eight or more heat exchanging tubes
of equilateral, triangular cross section are combined to form a
rhombic tube bundle.
[0008] Coolant may flow transversely in relation to the heat
exchanging tubes. Of course coolant may also flow longitudinally
along the heat exchanging tubes in a same direction or in
countercurrent direction.
[0009] According to another advantageous feature of the present
invention, a shell having a rhombic cross section may be provided
to ensheathe the heat exchanging tubes at a distance thereto. In
this way, the space available for coolant can be utilized in an
optimum manner. Advantageously, the shell can also be made of
steel.
[0010] According to another advantageous feature of the present
invention, the shell may have inclined walls, with bypass tubes
extending laterally adjacent to the inclined walls. The bypass
tubes, like the heat exchanging tubes, may have an equilateral
cross section. As an alternative, the bypass tubes may have a round
cross section.
[0011] According to another advantageous feature of the present
invention, a housing having a rectangular cross section may be
provided to ensheathe the tube bundle and the bypass tubes.
Advantageously, the housing can be made of steel sheet.
[0012] According to another advantageous feature of the present
invention, the heat exchanging tubes may also be placed in such a
way that the tube bundle exhibits a hexagonal configuration. As a
result, the shell may thus also be configured of hexagonal cross
section to ensheathe the heat exchanging tubes at a distance
thereto.
[0013] According to another advantageous feature of the present
invention, the heat exchanging tubes may be provided with
protuberances and/or grooves. In this way, heat transfer can be
optimized. The protuberances and/or grooves may have a round,
half-round, rhomboid, triangular, or oval configuration. The
protuberances and/or grooves may extend in longitudinal direction
of the heat exchanging tubes or also have a helical
configuration.
[0014] According to another advantageous feature of the present
invention, a turbulence generator can be inserted in the heat
exchanging tubes. This further enhances heat transfer.
[0015] According to another advantageous feature of the present
invention, a tube sheet may be provided to couple the heat
exchanging tubes to form the tube bundle. Currently preferred is a
configuration of the tube sheet in the form of a baffle plate or
optionally in the form of a sheet metal water deflector.
[0016] According to another advantageous feature of the present
invention, a heat exchanger according to the present invention may
form part of an exhaust gas recirculation system for an internal
combustion engine, wherein the hot gas is exhaust gas of the
internal combustion engine and the coolant is cooling water. In
other words, part of exhaust gas is recirculated in a cooled state
back to the combustion chamber of the internal combustion engine.
Recirculation of cooled exhaust gas results in an increased
proportion of inert gas in the air mixture. As a result of the
lesser oxygen concentration in the mixture, combustion progresses
more controlled and at lower combustion temperatures which reduce
development of NO.sub.x in the combustion chamber.
[0017] In view of the optimal triangular heat exchanging tubes in
the exhaust gas recirculation system, efficiency of the cooler can
be significantly increased while the installation space is the same
and the back pressure is reduced at the same time.
BRIEF DESCRIPTION OF THE DRAWING
[0018] Other features and advantages of the present invention will
be more readily apparent upon reading the following description of
currently preferred exemplified embodiments of the invention with
reference to the accompanying drawing, in which:
[0019] FIG. 1 is a schematic cross section of a basic principle of
a heat exchanger with two heat exchanging tubes;
[0020] FIG. 2 is a schematic cross section of another embodiment of
a heat exchanger;
[0021] FIG. 3 is a schematic cross section of the heat exchanger of
FIG. 2 with provision of additional bypass tubes;
[0022] FIG. 4 is a schematic cross section of a modification of the
heat exchanger of FIG. 3 with provision of an ensheathing
housing;
[0023] FIG. 5 is a schematic cross section of yet another
embodiment of a heat exchanger;
[0024] FIG. 6 is a schematic cross section of the heat exchanger of
FIG. 5 with provision of additional bypass tubes;
[0025] FIG. 7 is a schematic cross section of the heat exchanger of
FIG. 6 with provision of an ensheathing housing;
[0026] FIG. 8 is a schematic illustration of a heat exchanging tube
with grooves;
[0027] FIG. 9 is a schematic illustration of a heat exchanging tube
with inserted turbulence generator;
[0028] FIG. 10 is a schematic illustration of heat exchanging tubes
connected by a tube sheet;
[0029] FIG. 11 is a schematic illustration of heat exchanging tubes
connected by a sheet metal water deflector; and
[0030] FIG. 12 is a schematic illustration of a heat exchanging
tube with protuberances.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] Throughout all the figures, same or corresponding elements
may generally be indicated by same reference numerals. These
depicted embodiments are to be understood as illustrative of the
invention and not as limiting in any way. It should also be
understood that the figures are not necessarily to scale and that
the embodiments are sometimes illustrated by graphic symbols,
phantom lines, diagrammatic representations and fragmentary views.
In certain instances, details which are not necessary for an
understanding of the present invention or which render other
details difficult to perceive may have been omitted.
[0032] Turning now to the drawing, and in particular to FIG. 1,
there is shown a schematic cross section of a basic principle of a
heat exchanger, generally designated by reference numeral 1 and
including two heat exchanging tubes 2 which are made for example of
steel and arranged side-by-side. Hot gas HG flows through the heat
exchanging tubes 2 and coolant KF flows outside the heat exchanging
tubes 2. The heat exchanger 1 forms part of a not shown exhaust gas
recirculation system for an internal combustion engine, also not
shown. Thus, the hot gases HG involve hot exhaust from the internal
combustion engine for flow through the heat exchanging tubes 2,
whereas the coolant KF is cooling water flowing over the heat
exchanging tubes 2.
[0033] The heat exchanging tubes 2 have an equilateral triangular
cross section and are combined to form a tube bundle RB of rhombic
cross section, with two neighboring tube walls 3, 4 of the heat
exchanging tubes 2 extending side-by-side in parallel relation. A
cartridge or shell 5 made of steel for example and having a rhombic
cross section ensheathes the heat exchanging tubes 2 about their
circumference. FIG. 1 shows the presence of distances A of same
size between the heat exchanging tubes 2 as well as between the
heat exchanging tubes 2 and walls 6 of the shell 5.
[0034] FIG. 2 shows a schematic cross section of another embodiment
of a heat exchanger, generally designated by reference numeral 1a
and including a total of eight heat exchanging tubes 2 having
equilateral triangular cross section and combined to form tube
bundle RB of rhombic configuration. Of course, bundling of more or
less than eight heat exchanging tubes 2 to form tube bundle RB is
conceivable as well. The disposition of the heat exchanging tubes 2
in relation to one another and in relation to the peripheral shell
5 corresponds to those shown in FIG. 1 so that a further discussion
is not necessary.
[0035] FIG. 3 shows a schematic cross section of the heat exchanger
1a, with addition of bypass tubes 7, 7a being provided adjacent to
the heat exchanger 1a next to inclined walls 8 of the shell 5. The
bypass tubes 7, 7a are positioned in parallel relation to the heat
exchanging tubes 2 in proximity of wails 9 of the shell 5, which
extend horizontally in the drawing plane. The bypass tubes 7, 7a
may have equilateral triangular cross section and/or round cross
section. By way of example, bypass tubes 7 have equilateral
triangular cross section and bypass tubes 7a have round cross
section.
[0036] FIG. 4 shows a schematic cross section of a modification of
the heat exchanger 1a, and it can be seen that the shell 5 of
rhombic cross section which ensheathes the heat exchanging tubes 2
and the bypass tubes 7, 7a, is in turn surrounded by a housing 10
having rectangular cross section and being made of steel for
example.
[0037] FIG. 5 shows a schematic cross section of yet another
embodiment of a heat exchanger, generally designated by reference
numeral 1b. In the following description, parts corresponding with
those in FIG. 1 will be identified, where appropriate for the
understanding of the invention, by corresponding reference numerals
followed by a "b". The description below will center on the
differences between the embodiments. In this embodiment, the heat
exchanger 1b includes a total of six heat exchanging tubes 2 which
have equilateral triangular cross section and are combined to form
a hexagonal tube bundle RB1. The tube bundle RB1 is ensheathed by a
shell 5b of hexagonal configuration. The disposition of the heat
exchanging tubes 2 relative to one another and the disposition of
the heat exchanging tubes 2 relative to the peripheral shell 5b
correspond to those in the embodiment of FIG. 1 so that a further
discussion is not necessary.
[0038] FIG. 6 shows a schematic cross section of the heat exchanger
1b, with addition of bypass tubes 7, 7a being provided adjacent to
the heat exchanger 1b of hexagonal configuration next to inclined
walls 11 of the shell 5b which ensheathes the heat exchanging tubes
2 of equilateral triangular cross section. The bypass tubes 7, 7a
again may have equilateral triangular cross section and/or round
cross section. By way of example, bypass tubes 7 have equilateral
triangular cross section and bypass tubes 7a have round cross
section.
[0039] FIG. 7 shows a schematic cross section of a modification of
the heat exchanger 1b, and it can be seen that the shell 5b of
hexagonal cross section which ensheathes the heat exchanging tubes
2 and the bypass tubes 7, 7a, is in turn surrounded by a housing
10b having rhombic cross section.
[0040] The heat exchanging tubes 2 may be provided with grooves 12
and/or protuberances 16, as shown by way of example in FIGS. 8 and
12. The grooves 12 or protuberances 16 may have a round,
half-round, rhomboid, triangular, or oval configuration and extend
in longitudinal direction of the heat exchanging tubes. To enhance
heat transfer, the heat exchanging tubes 2 can have inserted
therein a turbulence generator 13, as shown in FIG. 9.
[0041] As shown in FIG. 10, a tube sheet 14 may be provided to
couple heat exchanging tubes 2 to form the tube bundle RB, RB1. The
tube sheet 14 can be configured in the form of a baffle plate or in
the form of a sheet metal water deflector 15, as shown in FIG. 11
by way of example.
[0042] While the invention has been illustrated and described in
connection with currently preferred embodiments shown and described
in detail, it is not intended to be limited to the details shown
since various modifications and structural changes may be made
without departing in any way from the spirit and scope of the
present invention. The embodiments were chosen and described in
order to explain the principles of the invention and practical
application to thereby enable a person skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated.
* * * * *