U.S. patent application number 10/561975 was filed with the patent office on 2007-06-07 for device for multi-stage heat exchange and method for producing one such device.
This patent application is currently assigned to BEHR GmgH & CO. KG. Invention is credited to Jochen Eitel, Markus Flik, Peter Geskes, Michael Lohle, Ulrich Maucher.
Application Number | 20070125527 10/561975 |
Document ID | / |
Family ID | 33521018 |
Filed Date | 2007-06-07 |
United States Patent
Application |
20070125527 |
Kind Code |
A1 |
Flik; Markus ; et
al. |
June 7, 2007 |
Device for multi-stage heat exchange and method for producing one
such device
Abstract
The invention relates to a device for multi-stage heat exchange
and to a method for producing one such device, whereby at least
three free-flowing media (fluids) are used in three flow devices
subdivided into at least two heat-exchanging or flow modules. Said
modules respectively consist of at least two flow elements that are
arranged in such a way that different fluids alternately flow
through the same. For essentially liquid fluids, the fluids are
distributed to the flow elements by means of fluid collecting
devices or fluid distributing devices connected in a gas-tight and
liquid-tight manner. The main flow directions of all fluids in the
flow elements are in essentially parallel planes. At least two flow
modules are directly mounted in series and/or by means of fluid
distributing devices in a flow-connected manner at least in
relation to one flow device.
Inventors: |
Flik; Markus; (Gerlingen,
DE) ; Eitel; Jochen; (Bissingen, DE) ; Geskes;
Peter; (Stuttgart, DE) ; Lohle; Michael;
(Esslingen, DE) ; Maucher; Ulrich;
(Korntal-Munchingen, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmgH & CO. KG
Stuttgart
DE
D-70469
|
Family ID: |
33521018 |
Appl. No.: |
10/561975 |
Filed: |
June 9, 2004 |
PCT Filed: |
June 9, 2004 |
PCT NO: |
PCT/EP04/06224 |
371 Date: |
May 22, 2006 |
Current U.S.
Class: |
165/140 ;
165/167 |
Current CPC
Class: |
F28D 9/0056 20130101;
F28F 2275/025 20130101; F28D 7/1692 20130101; F28D 9/0093 20130101;
F02B 29/0412 20130101; F01P 2003/182 20130101; F28D 7/0066
20130101; F28D 7/0083 20130101; F28D 9/005 20130101; F01P 2060/16
20130101; Y02T 10/12 20130101; F01P 7/165 20130101; F02B 29/0462
20130101; F28D 21/0003 20130101 |
Class at
Publication: |
165/140 ;
165/167 |
International
Class: |
F28F 3/08 20060101
F28F003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2003 |
DE |
103 28 746.0 |
Claims
1. An apparatus for heat exchange, having at least three flow
devices through which at least one flowable medium (fluid) flows;
at least one fluid inflow device, at least one fluid collection
and/or distribution device and at least one fluid outflow device
for each of the flow devices through which substantially liquid
fluids flow, wherein at least two flow assemblies are provided,
each having at least two flow elements, which are arranged in such
a manner that different fluids flow through them alternately, the
flow elements belonging to at least one flow device through which
substantially liquid fluids flow are connected in a substantially
gastight and liquid-tight, positively locking and/or nonpositively
locking and/or cohesive manner to at least one fluid collection
and/or distribution device, the main directions of flow of all the
fluids in the flow elements lie in planes that are substantially
parallel to one another, at least two flow assemblies are directly
connected in series in a positively locking and/or nonpositively
locking and/or cohesive manner and/or flow-connected by means of
fluid distribution devices, at least with respect to one flow
device.
2. An apparatus, in particular the apparatus as claimed in claim 1,
wherein the flow elements, at least in sections, are formed by in
particular, although not exclusively, hollow disks, flat tubes,
plates, layers and the like.
3. An apparatus, in particular the apparatus as claimed in claim 1,
wherein at least one fluid collection and/or distribution device is
formed at least in sections in particular, although not
exclusively, by hollow bodies and/or tubes.
4. An apparatus, in particular the apparatus as claimed in claim 1,
wherein at least one fluid collection and/or distribution device is
formed at least in part from longitudinal-side openings in the flow
elements, a first number of simple openings forming fluid inlets
and fluid outlets with respect to adjacent flow elements, and
sealing devices being arranged around a second number of openings,
in order to form passages in the corresponding flow element,
through which passages flow elements adjacent to this flow element
are flow-connected.
5. An apparatus, in particular the apparatus as claimed in claim 1,
wherein turbulence-generating and/or turbulence-increasing shaped
elements are provided.
6. An apparatus, in particular the apparatus as claimed in claim 1,
wherein the turbulence-generating and/or turbulence-increasing
shaped elements are taken from a group which includes in
particular, although not exclusively, fins, webs, studs, grooves,
stamped indentations or milled-out sections.
7. An apparatus, in particular the apparatus as claimed in claim 1,
wherein the turbulence-generating and/or turbulence-increasing
shaped elements are arranged in at least one flow element and/or
between at least two flow elements.
8. An apparatus, in particular the apparatus as claimed in claim 1,
wherein the profile of at least one flow element has
turbulence-generating and/or turbulence-increasing properties.
9. An apparatus, in particular the apparatus as claimed in claim 1,
wherein at least two flow elements through which different fluids
flow are connected on the longitudinal sides in a positively
locking and/or nonpositively locking and/or cohesive manner.
10. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least two flow elements through which the same fluid
flows are connected on the longitudinal sides by means of in
particular, although not exclusively, the turbulence-generating and
turbulence-increasing shaped elements which have their own profile
and/or are arranged between them, in such a manner that the at
least one cavity which is thereby formed between these flow
elements forms a flow element for a different fluid.
11. An apparatus, in particular the apparatus as claimed in claim
1, wherein the joins between the flow elements are taken from a
group which includes soldered joins, welded joins or adhesively
bonded joins.
12. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least one sealing element, which is formed in
particular, although not exclusively, by separating elements, blind
elements and/or hollow elements which are empty of fluid, is
provided between at least two flow elements through which different
fluids flow.
13. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least one of the sealing elements is arranged between
at least two flow assemblies.
14. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least one of the sealing elements has in particular,
although not exclusively, a hollow element which is empty of fluid,
a leaktightness control opening.
15. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least one of the sealing elements has at least one
leaktightness sensor, which causes a physically perceptible signal
to be output in the event of a fluid escaping from one of the flow
devices.
16. An apparatus, in particular the apparatus as claimed in claim
1, wherein at least two flow assemblies are separated from one
another in a substantially thermally insulating way, in particular,
although not exclusively, by hollow elements and/or separating
elements or by being arranged spaced apart.
17. An apparatus, in particular the apparatus as claimed in claim
1, wherein shaped elements are provided within at least one flow
element, which shaped elements, at least in sections, alter the
main direction of flow of the fluid flowing within the flow
element.
18. An apparatus, in particular the apparatus as claimed in wherein
at least one flow device has admixed with it, via at least one
further inflow device, a fluid, in particular, although not
exclusively, a fluid which corresponds to the fluid in this flow
device.
19. An apparatus, in particular the apparatus as claimed in claim
1, wherein the series connection according to the invention of at
least two flow assemblies with respect to at least one flow device
is effected in such a manner that the temperature gradient of the
fluid of this flow device along the flow path of this fluid from
the fluid inflow device to the fluid outflow device of this flow
device has a substantially constantly decreasing magnitude with
respect to each of the other fluids flowing through the flow
assemblies of the flow assembly series connection.
20. An apparatus, in particular the apparatus as claimed in
wherein, wherein fluids are mixed in the heat exchanger, it being
possible for different proportions of the overall fluid to flow
through different flow elements.
21. An apparatus, in particular the apparatus as claimed in claim
1, wherein a fluid is divided in the heat exchanger, it being
possible for different proportions of the divided fluid to flow
through different flow elements.
22. An apparatus, in particular the apparatus as claimed in claim
1, wherein in individual flow assemblies the heat is exchanged by
condensation or evaporation of a fluid.
23. An apparatus, in particular the apparatus as claimed in claim
1, wherein the individual flow assemblies can be operated as
crosscurrent, countercurrent or cocurrent heat exchange units.
24. An apparatus, in particular the apparatus as claimed in claim
1, wherein the heat exchanger is part of a cooling circuit, and the
individual flow assemblies are supplied with the fluid from a
further low-temperature and/or high-temperature cooling
circuit.
25. A process for producing an apparatus for heat exchange, in
which: at least three flow devices are formed, in particular,
although not exclusively, by punching out well-shaped metal plates,
which form flow elements, with longitudinal-side openings being
punched out, of which a first number of simple openings form fluid
inlets and outlets with respect to adjacent flow elements, and
sealing devices, in particular, although not exclusively, stamped
projections in the corresponding flow element which adjoin the
adjacent flow element in a cohesive and/or positively locking
and/or nonpositively locking manner, in order to form passages in
the corresponding flow element, through which passages flow
elements adjacent to this flow element are flow-connected, being
arranged around a second number of openings, wherein at least two
flow assemblies are formed by in particular, although not
exclusively, stacking the flow elements on top of one another, in
which case the flow elements are to be arranged in such a manner
that different fluids flow through them alternately, the main
directions of flow of all the fluids in the flow elements lie in
planes that are substantially parallel to one another, at least two
flow assemblies are directly connected in series in a positively
locking and/or nonpositively locking and/or cohesive manner and/or
in a manner flow-connected by means of fluid distribution devices,
at least with respect to one flow device, joins selected from a
group which includes soldered joins, welded joins or adhesively
bonded joins being produced between the flow elements, fluid
inflow, outflow, distribution and/or collection devices.
26. The use of an apparatus, in particular the apparatus as claimed
in claim 1, as an least two-stage heat exchanger for use in
land-based vehicles, aircraft or water-borne vehicles, in
particular for exhaust-gas cooling for an internal combustion
engine.
Description
[0001] The present invention relates to an apparatus for
multi-stage heat exchange, and to a process for producing an
apparatus of this type.
[0002] The demands imposed on modern cooling and air-conditioning
systems in vehicles are constantly rising. This is partly
attributable to the fact that the overall demand for cooling is
increasing and partly to the need to improve the efficiency of
cooling systems, the boundaries of which are being pushed further
and further. The improved utilization of heat sources and heat
sinks can lead to a higher degree of utilization of an overall
concept and also to a reduction in consumption. The configuration
of heat exchangers plays a central role in this overall
concept.
[0003] Cooling and heating concepts of the current state of the art
generally provide for single-stage heat transfer in heat
exchangers. In the process, fluids, such as for example coolant,
refrigerant, oil, exhaust gas or charge air, are cooled or heated.
The efficiency which can be achieved with single-stage temperature
control is normally limited. Therefore, to improve the performance
of cooling circuits, it is in some cases appropriate for a fluid to
be cooled or heated over two stages. This is possible if, in
addition to the fluid whose temperature is to be controlled, there
are two further fluids which are at two different temperature
levels.
[0004] In general, one drawback of the two-stage control of the
temperature of the fluids is that the use of two heat exchangers
connected in series in the conventional way entails considerably
increased costs as well as a greater installation space
requirement.
[0005] The invention is therefore based on the object of providing
an apparatus in which the at least two-stage cooling or heating of
a fluid can be of compact and inexpensive configuration.
[0006] According to the invention, the object is achieved by an
apparatus as claimed in claim 1. The process according to the
invention for producing an apparatus of this type forms the subject
matter of claim 20. Preferred embodiments and refinements form the
subject matter of the subclaims.
[0007] The apparatus according to the invention for heat exchange
has at least three flow devices, through which at least one
flowable medium (fluid) flows. After they have flowed through the
individual flow devices, it is also possible for at least two of
the at least three fluids to be mixed in the heat exchanger and
discharged together.
[0008] It is preferable for the majority of the heat, preferably
over 60%, in particular up to 70%, to be transferred in the first
flow assembly of the cooling or heating. In the context of the
present invention, the term flowable media or fluids is to be
understood as meaning liquid and/or gaseous media of any desired
viscosity, such as in particular, although not exclusively, oils,
liquids, in particular with a high heat of evaporation, water, air
or gases as well as refrigerants which can evaporate or condense.
The flowable media may in this case also contain additives, for
example for inhibiting corrosion.
[0009] Furthermore, the apparatus according to the invention has at
least one fluid inflow device, at least one fluid collection and/or
distribution device and at least one fluid outflow device for at
least one flow device through which substantially liquid fluids
flow.
[0010] According to the invention, at least two flow assemblies are
provided, each having at least two flow elements, which are
arranged in such a manner that different fluids flow through them
alternately. Furthermore, the flow elements belonging to a flow
device through which substantially liquid fluids flow are connected
in a substantially gastight and liquid-tight, positively locking
and/or nonpositively locking and/or cohesive manner to at least one
fluid collection and/or distribution device.
[0011] According to the invention, the main directions of flow of
all the fluids in the flow elements lie in planes that are
substantially parallel to one another. Furthermore, two flow
assemblies of the apparatus according to the invention are directly
connected in series in a positively locking and/or nonpositively
locking and/or cohesive manner and/or flow-connected by means of a
fluid distribution device, at least with respect to one flow
device.
[0012] In this context, a flow device is to be understood as
meaning a device through which a liquid or gaseous medium can flow
and which, in the case of the flow devices through which
substantially liquid fluids flow, is delimited in a substantially
gastight and liquid-tight manner with respect to the space
surrounding it. The flow devices are in this case formed by flow
elements which are flow-connected in series and/or in parallel.
[0013] In a preferred refinement of the apparatus according to the
invention, these flow elements, at least in sections, are formed by
in particular, although not exclusively, hollow disks, flat tubes,
plates and/or layers. In this context, hollow disks, plates or
layers are to be understood as meaning substantially gastight and
liquid-tight hollow bodies with inlet and outlet openings, the
length and width dimensions of which are considerably greater than
their height. In this context, the term flat tubes is to be
understood as meaning tubes which when seen in cross section have a
long side and a side which is significantly shorter than this long
side.
[0014] The flow elements may have one or more flow passages for the
medium flowing through them. They may run in a straight line but
they may also have a plurality of curved sections. In addition, the
flow elements may also have twisted sections, i.e. sections in
which the flow element is turned and/or wound in on itself.
[0015] In the context of the present invention, a fluid
distribution and/or collection device, in the case of the flow
devices through which substantially liquid fluids flow, is to be
understood as meaning substantially gastight and liquid-tight
hollow bodies within which fluids can flow and within which these
fluids are collected. At the same time, however, these fluid
distribution and/or collection devices can also be used to
distribute the respective fluids between a plurality of flow
elements and/or to collect them again from various flow
elements.
[0016] In the context of the present invention, the term
flow-connected is to be understood as meaning that a fluid can flow
between the flow elements, fluid distribution and/or collection
devices. The term substantially gastight and liquid-tight is to be
understood as meaning in particular, although not exclusively, a
division by separating devices, so that it is impossible for any
fluid to flow past the respective separating device along certain
directions of the flow devices, flow elements, fluid distribution
and/or collection devices.
[0017] The term direction of flow or main direction of flow of a
fluid is to be understood as meaning the direction which the fluid
preferably adopts within a flow device, a flow element and/or a
fluid distribution and/or collection device, disregarding locally
limited changes in direction of the fluid.
[0018] In a preferred embodiment, the fluid distribution and/or
collection devices are, in the broader sense, collection and/or
distribution tubes.
[0019] In another preferred embodiment, at least one fluid
collection and/or distribution device is formed at least in part
from longitudinal-side openings in the flow elements, a first
number of simple openings forming fluid inlets and fluid outlets
with respect to adjacent flow elements, and sealing devices being
arranged around a second number of openings, in order to form
passages in the corresponding flow element, through which passages
flow elements adjacent to this flow element are flow-connected.
[0020] In the context of the invention, the first number of
longitudinal-side openings in flow elements, preferably in hollow
disks, plates or layers, are to be understood as meaning in
particular, although not exclusively, round punched-out apertures
or drilled holes which are provided in the significantly longer and
wider sides of the flow elements.
[0021] The sealing devices around the second number of
longitudinal-side openings in flow elements, preferably in hollow
disks, plates or layers, in the context of the invention are to be
understood as meaning in particular, although not exclusively,
stamped projections, which adjoin the adjacent flow element in a
cohesive and/or positively locking and/or nonpositively locking
manner, in the corresponding flow element or sealing rings.
[0022] It is preferable for partition walls to be provided in a
substantially gastight and liquid-tight manner in individual
openings, allowing preferred control of the fluid distribution by
in particular, although not exclusively, stacking identical
plate-like flow elements on top of one another.
[0023] In another preferred embodiment of the apparatus according
to the invention, turbulence-generating and/or
turbulence-increasing shaped elements are preferably provided
within the flow device, which shaped elements in particular
contribute to increasing the heat transfer coefficient between the
fluids of the various flow devices. It is preferable for these
turbulence-generating or turbulence-increasing shaped elements to
be taken from a group which includes in particular, although not
exclusively, fins, webs, studs, grooves, stamped indentations or
milled-out sections.
[0024] In another preferred embodiment, the turbulence-generating
and/or turbulence-increasing shaped elements are arranged in at
least one flow element and/or between at least two flow elements.
Furthermore, the profile of at least one flow element preferably
has turbulence-generating and/or turbulence-increasing
properties.
[0025] In another preferred embodiment, turbulence inlays are
provided, preferably to be laid in at least one flow element, in
particular, although not exclusively, in hollow disks, plates
and/or layers.
[0026] In the context of the invention, turbulence inlays are to be
understood as meaning in particular, although not exclusively,
metal sheets which have turbulence-generating and/or
turbulence-increasing shaped elements, such as for example fins,
webs, studs, grooves, stamped indentations and/or milled-out
sections and are laid in the flow elements, in a manner which
simplifies production, preferably with external dimensions
corresponding to the internal dimensions of the flow elements, and
preferably with punched-out apertures corresponding to the
distribution devices with leaktightness device, in particular the
stamped projections in the flow elements, for the passages through
which adjacent flow elements are flow-connected.
[0027] In another preferred embodiment of the apparatus according
to the invention, at least two flow elements through which
different fluids flow are connected on the longitudinal sides in a
positively locking and/or nonpositively locking and/or cohesive
manner.
[0028] In another preferred embodiment, at least two flow elements
through which the same fluid flows are connected on the
longitudinal sides by means of in particular, although not
exclusively, the turbulence-generating and turbulence-increasing
shaped elements which have their own profile and/or are arranged
between them, in such a manner that at least one cavity which is
thereby formed between these flow elements forms a flow element for
a different fluid.
[0029] In another embodiment, the joins between the flow elements
are taken from a group which includes soldered joins, welded joins
or adhesively bonded joins.
[0030] In another preferred embodiment, at least one sealing
element, which is formed in particular, although not exclusively,
by separating elements and/or hollow elements which are empty of
fluid, is provided at least between two flow elements through which
different fluids flow.
[0031] It is preferable for at least one sealing element to be
arranged between flow assemblies which are in series.
[0032] In another preferred embodiment, at least one of the sealing
elements has in particular, although not exclusively, a hollow
element which is empty of fluid, a leaktightness control opening.
This proves advantageous in particular during production of the
apparatus according to the invention, since then the individual
flow devices are first of all individually filled with their
respective fluids, and should the respective flow device prove not
to be leaktight, for example as a result of a fault in the
production process, it is possible for the fluid which escapes to
be collected in the hollow or blind element, which is initially
empty of fluid, and to demonstrate the lack of leaktightness by
emerging at the leaktightness control opening.
[0033] The method of first of all filling each individual flow
device with its corresponding fluid also makes it possible for the
gastightness and liquid-tightness according to the invention of the
various flow devices with respect to one another to be checked as a
result of the fluid which has in each case been introduced passing
into a second flow device.
[0034] In another preferred embodiment of the apparatus according
to the invention, at least one of the sealing elements has at least
one leaktightness sensor, which causes a physically perceptible
signal to be output in the event of a fluid escaping from one of
the flow devices.
[0035] In another preferred embodiment, at least two flow
assemblies are separated from one another in a substantially
thermally insulating manner, for example simply by being arranged
spatially spaced apart, and/or alternatively by means of hollow
elements that are empty of fluid in particular arranged between
them.
[0036] In another preferred embodiment, shaped elements are
provided within at least one flow element, which shaped elements,
at least in sections, alter the main direction of flow of the fluid
flowing within the flow element.
[0037] In another embodiment, at least one flow device has admixed
with it, via at least one further inflow device, a fluid, in
particular, although not exclusively, a fluid which corresponds to
the fluid in this flow device.
[0038] In another preferred embodiment, the series connection
according to the invention of at least two flow assemblies with
respect to at least one flow device is effected in such a manner
that the temperature gradient of the fluid of this flow device
along the flow path of this fluid from the fluid inflow device to
the fluid outflow device of this flow device has a substantially
constantly decreasing magnitude with respect to each of the other
fluids flowing through the flow assemblies of the flow assembly
series connection.
[0039] In another preferred embodiment, fluids are mixed in the
heat exchanger, it being possible for different proportions of the
overall fluid to flow through different flow elements.
[0040] Another preferred embodiment allows a fluid to be divided in
the heat exchanger, it being possible for different proportions of
the divided fluid to flow through different flow elements.
[0041] In another preferred embodiment, the heat exchange in
individual flow assemblies takes place by condensation or
evaporation of a fluid.
[0042] In further preferred embodiments, the individual flow
assemblies can be operated as crosscurrent, countercurrent or
cocurrent heat exchange units.
[0043] In another preferred embodiment, the heat exchanger is part
of a cooling circuit, and the individual flow assemblies are
supplied with the fluid via a further low-temperature and/or
high-temperature cooling circuit.
[0044] In another preferred embodiment, the heat exchanger is used
as an at least two-stage heat exchanger for use in land-based
vehicles, aircraft or water-borne vehicles, in particular for
exhaust-gas cooling for an internal combustion engine.
[0045] Further advantages, features and possible applications of
the present invention will emerge from the following description of
exemplary embodiments, in conjunction with the figures, in
which:
[0046] FIG. 1 shows a diagrammatic section through a heat exchange
apparatus according to the invention with disk stacks arranged on
top of one another as flow assemblies;
[0047] FIG. 2 shows a perspective partially exploded view of the
two-stage heat exchanger from FIG. 1;
[0048] FIG. 3 shows an upper longitudinal section view of two types
of disk for another embodiment of the heat exchange apparatus
according to the invention;
[0049] FIG. 4 shows an upper longitudinal section view of two types
of disk for another exemplary embodiment of the heat exchange
apparatus according to the invention;
[0050] FIG. 5 shows an upper longitudinal section view of two types
of disk for another exemplary embodiment of the heat exchange
apparatus according to the invention;
[0051] FIG. 6 shows a perspective ghosted view of another exemplary
embodiment of the heat exchange apparatus according to the
invention with flow assemblies arranged on top of one another;
[0052] FIG. 7 shows a perspective ghosted view of another exemplary
embodiment of the heat exchange apparatus according to the
invention with flow assemblies arranged next to one another;
[0053] FIG. 8 shows a perspective ghosted view of another exemplary
embodiment of the heat exchange apparatus according to the
invention with flow assemblies for a gaseous fluid 2 arranged on
top of one another;
[0054] FIG. 9 shows a perspective ghosted view of another exemplary
embodiment of the heat exchange apparatus according to the
invention with flow assemblies arranged on top of one another and
an alternative arrangement of an outflow device.
[0055] FIG. 10 shows a perspective ghosted view of another
exemplary embodiment of the heat exchange apparatus according to
the invention with flow assemblies arranged next to one another and
a common fluid outflow device;
[0056] FIG. 11 shows two plan views of further exemplary
embodiments of the heat exchange apparatus according to the
invention;
[0057] FIG. 12 shows a cooling circuit in which the heat exchanger
shown in FIG. 10 has been integrated.
[0058] A first exemplary embodiment of the invention will now be
described with reference to FIGS. 1 and 2. These figures show a
diagrammatic section through a two-stage heat exchanger, the flow
elements of which are disks and the heat exchange or flow
assemblies of which are formed by disk stacks arranged on top of
one another with a hollow disk arranged between them, and a
perspective partially exploded view of the same heat exchanger,
respectively.
[0059] In FIG. 1, the fluid 1 flows in at the top left via the
inflow device 10 through the cover 5 into the flow assembly 120 and
passes first of all through a second opening 100 with stamped
projection through the top disk 22 into the top disk 12 as flow
element for fluid 1. From there, the fluid 1 has two possible
directions of flow, namely on the one hand substantially diagonally
over the top disk 12 to the first opening 102 illustrated in FIG.
2, in which case along this path heat is exchanged with the fluid 2
flowing through the disks 22 located above and/or below.
[0060] Then, fluid 1 passes through the first opening 102 through a
corresponding stamped projection in the disk 22 below, which in
turn has fluid 2 flowing through it, into the following disks 12.
On the other hand, the first opening 101 illustrated in FIG. 2 also
allows passage through the disk 22 below to the following disks 12.
However, a direct flow path for fluid 1 directly through the first
and second openings of the disks of both flow assemblies from the
inflow device 10 to the outflow device 11 without the fluid 1
having to flow across the disks 12 of the lower flow assembly 130
is blocked by means of the partition wall 71.
[0061] Finally, from the bottom disk 12 of the upper flow assembly
120, fluid 1 flows through a corresponding stamped projection in
the blind disk 7 into the flow assembly 130 which is thereby
connected in series with flow assembly 120 with regard to fluid 1
and which forms a second heat exchange stage, the disks 12 of which
produce similar flow paths between the disks 32 through which fluid
3 flows, which now allows heat exchange between fluids 1 and 3.
[0062] The partition walls 72 and 73, as well as 74 and 75,
separate the disks 22, as the main part of the flow device for
fluid 2, from the disks 32, as the main part of the flow device for
fluid 3. Finally, fluid 1 emerges from the two-stage heat exchanger
9 through the base 6 and the outflow device 11.
[0063] In a similar way, fluid 2 flows through the disks 22 of the
upper flow assembly 120 and fluid 3 flows through the disks 32 of
the lower flow assembly 130, with the outflow devices 21 and 31 for
fluids 2 and 3, respectively, corresponding to the inflow devices
20 and 30, in each case being arranged on the same side, i.e. at
the top for fluid 2 and at the bottom for fluid 3.
[0064] The blind disk 7, which is empty of fluid, on the one hand
allows thermal insulation of the flow assemblies 120 and 130, which
are preferably at different temperature levels, and on the other
hand is also used to check the leaktightness and to prevent fluids
3 and 2, in operation, from becoming mixed unnoticed in the event
of leaks occurring in the two flow devices and/or fluid circuits.
The blind disk 7 is closed on all sides and has a small opening 8
to the outside on the side of its edge web. In the event of a leak,
the respective fluid can flow out through this opening and does not
penetrate into a different flow device.
[0065] Turbulence-generating fins or elements may be laid between
the disks 12, 22 and 32, and/or the disks themselves have
stamped-in fins, webs, and/or studs (not shown here). A
predetermined compressive strength is achieved by soldering the
elevations in the form of the inlays or stamped indentations from
disk to disk.
[0066] FIG. 3 illustrates an upper longitudinal section view of the
two types of disk for a two-stage heat exchanger which is formed
from disks and in which two fluids within the first type of disk 15
are separated by means of two parallel webs 77, with in each case
two smaller first openings 121, 122 and 131, 132 being provided as
inlet and outlet for fluids 2 and 3. Furthermore, the first type of
disk 15 has two larger second openings 113 and 114 with an
encircling stamped projection as a passage opening for fluid 1.
[0067] By contrast, the second type of disk 25 in each case has two
smaller second openings 123 and 124, and 133 and 134, with an
encircling stamped projection for the passage of fluid 2 or 3,
respectively, through the second type of disk 25, as well as two
larger first openings 111 and 112 as inlet and outlet for fluid 1
into and out of the second type of disk 25.
[0068] FIG. 4 illustrates another variant of the two types of disk
for a two-stage heat exchanger formed from disks, in which fluids 2
and 3 are supplied via separate fluid inflow devices. The inlet and
passage of fluid 2 and 3 into or through the first type of disk 17
is effected by means of two smaller third openings 126 and 136 with
an interrupted encircling stamped projection. Two smaller second
openings 125 and 135 with an encircling stamped projection allow
fluids 2 and 3 to pass through. Fluids 2 and 3 are mixed within the
first type of disk 17 and discharged via an additional, larger
first opening 1231.
[0069] An additional, larger second opening 1232 with encircling
stamped projection located in the second type of disk 27 allows the
mixture of fluids 2 and 3 to pass through the second type of disk
27. It is preferable for fluids 2 and 3 to be one fluid which,
however, is at different temperature levels at the fluid inflow
devices. In this embodiment, the mixing of the fluids means that
there is no need for the flow devices to be separated by means of
the webs 77 shown in FIG. 3. A characteristic of this embodiment is
that the fluid 2 exchanges heat in cocurrent with fluid 1, and
fluid 3 exchanges heat in countercurrent with fluid 1.
[0070] FIG. 5 represents an upper longitudinal section view of the
two types of disk for a two-stage heat exchanger formed from disks
as shown in FIG. 3, with an additional, larger first opening 141
acting as inlet for a fluid 4, preferably corresponding to fluid 1,
into the second type of disk 26 being provided in the second type
of disk 26. It is preferable for fluid 4 to be at a different
temperature level than fluid 1 and/or it may also contain, for
example, corrosion-inhibiting additives.
[0071] FIG. 6 shows a perspective ghosted view of a two-stage heat
exchanger, the flow elements of which are formed from flat tubes 40
and cavities 50 between them, the flow assemblies according to the
invention for fluids 1 and 2 or fluids 1 and 3 being arranged on
top of one another, and the fluid 1 whose temperature is to be
controlled having its inlet and outlet on the same side. Cooling
fins 99 which increase the surface area and contribute to
increasing the heat transfer coefficient between fluids 1 and 2 are
indicated between the flat tubes. The compressive strength is
increased by soldering the cooling fins 99 from flat tube to flat
tube.
[0072] FIG. 7 shows a perspective ghosted view of a two-stage heat
exchanger, the flow elements of which are formed from flat tubes 41
and from cavities 51 between them, with the flow assemblies
according to the invention for fluids 1 and 2 or fluids 1 and 3
being arranged next to one another and the fluid 1 whose
temperature is to be controlled having its inlet and outlet on
opposite sides.
[0073] FIG. 8 shows a perspective ghosted view of a two-stage heat
exchanger, the flow elements of which are formed from flat tubes
and from cavities between them, with the flow assemblies according
to the invention for fluids 1 and 2 or fluids 1 and 3 being
arranged on top of one another, in accordance with FIG. 5, but with
the possibility of dispensing with a feed and a discharge and a
housing for the flow assembly for fluids 1 and 2, on account of the
use of a gaseous fluid 2, preferably the ambient air. The direction
of flow of the fluid 2 is indicated by the arrow illustrated next
to the corresponding reference numeral.
[0074] FIG. 9 illustrates a perspective ghosted view of a two-stage
heat exchanger in accordance with FIG. 5, with the second heat
exchange stage in the form of the flow assembly for fluids 1 and 3
being used or dispensed with depending on the alternative
arrangement, indicated by the dashed outflow direction of fluid 1,
of the outflow device for fluid 1 on the same side as or the
opposite side to the inflow for fluid 1.
[0075] FIG. 10 illustrates a perspective ghosted view of a
two-stage heat exchanger as shown in FIG. 7, in which it is
possible to use more flat tubes than in FIG. 7. A characteristic
feature of this exemplary embodiment is that fluids 2 and 3 are one
fluid, similarly to in FIG. 4. In this exemplary embodiment, fluids
2 and 3 flow into the heat exchanger at different mass flow rates
and temperatures. The two fluids mix with one another substantially
in the common fluid collection device for fluids 2 and 3 and then
flow out in mixed form via the common fluid outflow device. FIG. 10
additionally shows a plan view of this exemplary embodiment which
illustrates that the flow assembly comprising the fluids 1 and 3 is
operated predominantly in cocurrent, the flow assembly comprising
the fluids 1 and 2 is operated predominantly in countercurrent and
not predominantly in crosscurrent in accordance with FIG. 7.
[0076] This variant has advantages with regard to the cooling of
exhaust gases. In the high-temperature flow assembly (HT flow
assembly) comprising the fluids 1 and 3, in accordance with the
plan view, a very large amount of coolant flows in cocurrent with
the very hot exhaust gas through the cooler. The cocurrent
arrangement substantially prevents the coolant from boiling. In the
low-temperature flow assembly (LT flow assembly) comprising the
fluids 1 and 2, a considerably smaller cool mass flow of coolant
flows in countercurrent to the exhaust gas, which has already been
greatly cooled. Here, countercurrent connection can be permitted,
since there is no longer a risk of boiling, on account of the
exhaust-gas cooling which has already taken place. The
countercurrent connection has the advantage that the heat exchange
between exhaust gas and coolant is very high and the exhaust gas
can be intensively cooled.
[0077] FIG. 11 shows that the position of the fluid inflow and
outflow device, depending on the particular application, may also
be set in such a way that the flow through the entire cooler is in
countercurrent (A) or cocurrent (B). This is possible if there is
no risk of the coolant(s) boiling.
[0078] FIG. 12 diagrammatically depicts the incorporation of a
cooler 300 as shown in FIG. 10 for the case of exhaust gas cooling
for an internal combustion engine 400. Numerous circuit
arrangements are conceivable; it is advantageous if the LT flow
assembly 311 of the cooler 300 has a low mass flow, which is cooled
to a very low temperature by air in a separate low-temperature
cooler 310, flowing through it. This low mass flow is branched off
from the main flow downstream of the main air cooler 320 and cooled
in the low-temperature cooler 310. The HT flow assembly 321 of the
two-stage cooler 300 has a greater mass flow at a higher
temperature level, which is branched off directly from the mass
flow of coolant flowing to the main air cooler 320, flowing through
it.
[0079] It is also conceivable for the two-stage heat exchanger to
have a dedicated coolant circuit, i.e. not to be incorporated in
the actual engine cooling circuit. It is also possible for the LT
circuit to have a dedicated pump.
* * * * *