U.S. patent application number 14/374052 was filed with the patent office on 2015-09-10 for heat exchanger.
This patent application is currently assigned to A-HEAT Allied Heat Exchange Technology AG. The applicant listed for this patent is A-HEAT Allied Heat Exchange Technology AG. Invention is credited to Marek Pyza.
Application Number | 20150253086 14/374052 |
Document ID | / |
Family ID | 45558728 |
Filed Date | 2015-09-10 |
United States Patent
Application |
20150253086 |
Kind Code |
A1 |
Pyza; Marek |
September 10, 2015 |
HEAT EXCHANGER
Abstract
Disclosed is a heat exchanger having a plurality of sheet
element arrangements, wherein the arrangements contain a plurality
of openings, wherein adjacent openings are separated from one
another, wherein in operation the openings are flowed through by a
first. The openings extend at least sectionally separately from one
another within the sheet element arrangement, wherein adjacent
sheet element arrangements are each arranged at a spacing from one
another so that a second fluid can flow in the intermediate space
between two adjacent sheet element arrangements. At least one of
the arrangements is interrupted by a cut-out so that the
arrangement has at least one first sheet element and one second
sheet element, with the second sheet element being so arranged such
that the second sheet element can be flowed through by the first
fluid subsequent to the first sheet element, with the cut-out
containing a flow-directing element.
Inventors: |
Pyza; Marek;
(Fuerstenfeldbruck, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
A-HEAT Allied Heat Exchange Technology AG |
Wien |
|
AT |
|
|
Assignee: |
A-HEAT Allied Heat Exchange
Technology AG
Wien
AT
|
Family ID: |
45558728 |
Appl. No.: |
14/374052 |
Filed: |
January 30, 2012 |
PCT Filed: |
January 30, 2012 |
PCT NO: |
PCT/EP2012/051454 |
371 Date: |
March 31, 2015 |
Current U.S.
Class: |
165/166 |
Current CPC
Class: |
F28F 2260/02 20130101;
F28D 1/05383 20130101; F28D 1/05391 20130101; F28F 1/022 20130101;
F28F 2210/08 20130101; F28F 3/08 20130101; F28D 1/05366 20130101;
F28F 13/06 20130101; F28D 7/1684 20130101; F28F 2210/00 20130101;
F28D 2001/028 20130101 |
International
Class: |
F28F 3/08 20060101
F28F003/08 |
Claims
1. A heat exchanger (1) which has a housing which contains a
plurality of sheet element arrangements (2, 12, 22), wherein the
sheet element arrangements contain a plurality of openings (6),
wherein adjacent openings are separated from one another, wherein
the openings are flowed through by a first fluid (7) in the
operating state, wherein the openings extend at least sectionally
separately from one another within the sheet element arrangement,
wherein adjacent sheet element arrangements are each arranged at a
spacing from one another so that a second fluid (8) can flow in the
intermediate space (15) between two adjacent sheet element
arrangements (2, 12, 22), wherein at least one of the sheet element
arrangements (2, 12, 22) is interrupted by a cut-out (5) so that
the sheet element arrangement has at least one first sheet element
(3) and one second sheet element (4), with the second sheet element
(4) being arranged with respect to the first sheet element (3) such
that the second sheet element (4) can be flowed through by the
first fluid (7) subsequent to the first sheet element (3), with the
cut-out (5) containing a flow-directing element (20).
2. The heat exchanger in accordance with claim 1, wherein the
cut-out (5) is designed so that a plurality of openings (6) at a
second end (17) of the first sheet element (3) open into the
cut-out (5) and the first fluid (7) can in turn be fed from the
cut-out (5) into a plurality of openings (6) which are arranged at
a first end (18) of the second sheet element (4).
3. The heat exchanger in accordance with claim 1, wherein the
cut-out contains a flow disruption element and/or a static
mixer.
4. The heat exchanger in accordance with claim 1, wherein the
cut-out is surrounded by a jacket element which is connected in a
fluid-tight manner to the first and second sheet elements.
5. The heat exchanger in accordance with claim 4, wherein the
jacket element contains the flow-directing element (20) which can
be designed as a fin (21) and/or as a groove (23) and/or as a
projection (25).
6. The heat exchanger in accordance with claim 1, wherein the
cut-out (5) is formed by the second end (17) of the first sheet
element (3), by the first end (18) of the second sheet element (4)
and by the jacket element (10, 11), with the first sheet element
(3) and the second sheet element (4) having a common center plane
and the sheet elements being arranged behind one another with
respect to the flow direction of the first fluid (7).
7. The heat exchanger in accordance with claim 1, wherein the
openings (6) are formed as channels (9) in the sheet elements (3,
4).
8. The heat exchanger in accordance with claim 7, wherein the
flow-directing element (20) is arranged at least sectionally at an
angle (27) to the channels (9).
9. The heat exchanger in accordance with claim 7, wherein the
flow-directing element (20) includes an angle (27) with the
channels (9) which is in the range from 10.degree. up to and
including 75.degree., preferably in the range from 10.degree. up to
and including 60.degree., particularly preferably in the range from
10.degree. up to and including 45.degree..
10. The heat exchanger in accordance with claim 4, wherein the
jacket element contains projections which project into the cut-out
and form flow disruption elements.
11. The heat exchanger in accordance with claim 1, wherein the
cut-out extends over between 5% and 40% of the length (26) of the
heat exchanger, with the length (26) of the heat exchanger being
measured in the main flow direction of the first fluid (7) flowing
within the sheet elements.
12. The heat exchanger in accordance with claim 1, wherein the
cut-out (5) substantially extends over the total width (28) of the
heat exchanger.
13. The heat exchanger in accordance with claim 1, wherein an
installation element (13) is provided for maintaining the spacing
between two adjacent sheet element arrangements (2, 12, 22).
14. The method of operating a heat exchanger in accordance with
claim 1, including a step in which the first fluid (7) is mixed on
its flow path within the sheet element arrangement (2, 12, 22)
between its inlet into the sheet element arrangement and its outlet
from the sheet element arrangement.
15. The method in accordance with claim 14, wherein the second
fluid (8) flowing between adjacent sheet element arrangements flows
in a cross-flow to the first fluid (7).
Description
[0001] The invention relates to a heat exchanger for the exchange
of heat between a coolant and a gas which can in particular be
air.
[0002] The use of heat exchange systems is known in a number of
applications from the prior art which can practically not be
overseen. Heat exchangers are used in refrigeration systems such as
in common domestic refrigerators, in air-conditioning plants for
buildings or in vehicles of all kinds, above all in motor vehicles,
aircraft and ships, as water coolers or oil coolers in internal
combustion engines, in mobile or stationary operation, as
condensers or evaporators in refrigerant circuits.
[0003] A heat exchanger of this type is known, for example, from
U.S. Pat. No. 4,876,778. The structure of the heat exchanger is
such that cooling water flows within tubes which are arranged
between a plurality of sheets and air flows around the sheets.
Cooling water and air flow toward one another in a cross-flow. The
provided sheets are arranged in parallel to one another and are
separated from one another by spacer elements. Such spacer elements
can be formed as corrugated sheets, for example.
[0004] In the following, a distinction should be made between
"laminar heat exchangers", on the one hand, and "minichannel heat
exchangers" or "microchannel heat exchangers", on the other
hand.
[0005] The laminar heat exchangers which have been well known for a
very long time serve, like all types of heat exchangers, for the
transfer of heat between two media, e.g. from a coolant to air or
vice versa. The first fluid flowing in the interior of the channels
of the heat exchanger is also called a heat carrier in the
following. The second fluid flowing around the channels is called a
transport fluid in the following. Both the heat carrier and the
transport fluid can be present in the liquid or gaseous state.
Water, oil, air or a coolant can be named by way of example as the
heat carrier or the transport fluid. One of these media is cooled
correspondingly by the heat transfer, whereas the other medium is
heated.
[0006] Generally, the transport fluid, that is e.g., the air, has a
considerably smaller heat transfer coefficient than the heat
carrier, that is e.g. the coolant or heating medium, which
circulates within the channels of the heat exchanger. This is
balanced by greatly different heat transfer surfaces for the two
media. The medium having the high heat transfer coefficient flows
in the channel. Thin metal sheets, e.g. ribs or lamellae, are
attached to its outer side so that the outer surface of the channel
has a heat transfer surface which is enlarged in comparison with
the inner surface of the channel and at which the heat transfer
with the transport fluid takes place.
[0007] The ratio of outer surface to inner surface of the channel
in this respect depends on the lamella geometry, which is in turn
determined by the channel diameter, the arrangement of the channels
and the spacing of the channels from one another, and on the
lamella spacing d'. The lamella spacing d' is selected differently
for different applications. Purely thermodynamically, however, it
should be as small as possible, but not so small that the pressure
loss on the side of the transport fluid is too large.
[0008] An efficient optimum is at approximately 2 mm, which is a
typical value for condensers and dry coolers.
[0009] The efficiency is in this respect substantially determined
by the fact that the heat which is transferred between the lamella
surface and the transport fluid has to be transferred to the
channel via heat conduction through the lamellae. This heat
transfer is the more effective, the higher the conductivity or the
thickness of the lamella is, but also the smaller the spacing
between the channels is. One speaks of lamella efficiency here.
Aluminum is therefore primarily used as the lamella material today
which has a high heat conductivity (approx. 220 W/mK) at economic
conditions. The spacing of the channels should be as small as
possible in this respect. Thermodynamically, a solution would be
ideal which has a plurality of channels with small diameters at a
small spacing from one another. A substantial cost factor is,
however, also the working time for the widening and soldering of
the channels. It would increase very disproportionately with such a
geometry.
[0010] A new class of heat exchangers, so-called minichannel or
also microchannel heat exchangers, was therefore already developed
some years ago which are manufactured using a completely different
process and almost correspond to the ideal of a laminar heat
exchanger. They contain minichannels or microchannels with a very
small diameter which is in the order of 1 mm. Extruded aluminum
sections are preferably used for the manufacture of these
minichannels or microchannels.
[0011] A heat exchanger block is essentially made up of one or more
laminar heat exchangers or from one or more microchannel heat
exchangers, with in each case an inlet side of the heat exchanger
block being soldered in a pressure tight manner to an outlet
element and with an outlet side of the heat exchanger block being
soldered in a pressure tight manner to an inlet element. A
connection flange is provided in each case in this respect at the
outlet element and at the inlet element of the heat exchanger block
including one or more heat exchangers so that the heat exchanger
block can be flow-connected to an external system, e.g. to a
refrigeration machine, such that the heat carrier can be supplied
from the outlet element through the heat exchanger to the inlet
element in the operating state for the exchange of heat with the
transport fluid under a predefinable operating pressure.
[0012] The microchannels are arranged in sheet elements. The
microchannels extend substantially parallel to one another and are
not connected to one another so that the heat carrier, that is the
first fluid, is supplied to the sheet element in a microchannels,
flows through the sheet element in this microchannel and leaves
again in the same microchannel. The transport fluid flows to the
microchannels in cross channels. The transport fluid outputs heat
to the heat carrier or takes up heat from the heat carrier via the
walls of the sheet element. Due to the cross-flow, the ingoing
temperature of the transport fluid therefore differs from its
outgoing temperature since heat is either taken up or output on the
path through the heat exchanger. This causes an inhomogeneous
temperature distribution in the microchannels.
[0013] In large-area heat exchangers having a heat exchange surface
of a plurality of square meters, these temperature differences can
result in heat stresses and thus in mechanical stresses of the
microchannels which can result in damage to the heat exchanger.
[0014] It is therefore an object of the invention to homogenize the
temperature distribution in the coolant in the flow direction of
the gas.
[0015] The object of the invention is satisfied by a heat exchanger
having the following features: The heat exchanger has a housing
which contains a plurality of sheet element arrangements. The sheet
element arrangements contain openings, for example in the form of
tubes, which can be flowed through by a first fluid in the
operating state. Microchannels in the sense of the preceding
statements can also be provided. The openings extend at least
sectionally separate from one another within the sheet element
arrangement. Adjacent sheet element arrangements are each arranged
at a spacing from one another so that a second fluid can flow in
the intermediate space between two adjacent sheet element
arrangements. The flow direction of the second fluid preferably
takes place substantially cross-wise to the flow direction of the
first fluid. This means that the first fluid and the second fluid
preferably flow in a cross-flow toward one another.
[0016] At least one of the sheet element arrangements is
interrupted by a cut-out so that the sheet element arrangement has
at least one first sheet element and one second sheet element. The
second sheet element is arranged with respect to the first sheet
element such that the second sheet element can be flowed through by
the first fluid subsequent to the first sheet element, with the
cut-out containing a flow-deflecting element. A mixture of the
individual flows of the first fluid which reach the cut-out via the
openings takes place within the cut-out.
[0017] In accordance with an embodiment, the cut-out is designed
such that a plurality of openings open unto the cut-out at a second
end of the first sheet element and the first fluid can in turn be
fed from the cut-out into a plurality of openings at a first end of
the second sheet element. The cut-out can in particular be designed
such that a plurality of tubes, channels or microchannels open into
such a cut-out at a first end thereof and the first fluid is in
turn fed from the cut-out into a plurality of tubes, channels or
microchannels of the second sheet element.
[0018] In accordance with an embodiment, the cut-out contains a
flow disruption element so that an eddy formation and/or deflection
of the flow takes place. Alternatively or additionally to this, the
cut-out can contain a static mixer. The cut-out can be surrounded
by a jacket element which is connected in a fluid-tight manner to
the first and second sheet elements. The jacket element can in
particular contain the flow-directing element such as grooves
and/or fins and/or projections. The cut-out is formed by the second
end of the first sheet element, by the first end of the second
sheet element and by the jacket element, with the first sheet
element and the second sheet element having a common center plane
and the sheet elements being arranged behind one another with
respect to the flow direction of the first fluid.
[0019] The openings can in particular be formed as channels in the
sheet elements. The grooves can be arranged at least sectionally at
an angle to the channels. The grooves can include an angle with the
channels which is in the range from 10.degree. up to and including
75.degree., preferably in the range from 10.degree. up to and
including 60.degree., particularly preferably in the range from
10.degree. up to and including 45.degree..
[0020] In accordance with an alternative embodiment, the jacket
element can include projections which project into the cut-out and
form flow disruption elements.
[0021] The cut-out advantageously extends over between 5% and 40%
of the length of the heat exchanger, with the length of the heat
exchanger being measured in the main flow direction of the first
fluid flowing within the sheet elements. To ensure a temperature
compensation over the total width of the heat exchanger, it is
advantageous if the cut-out extends substantially over the total
width of the heat exchanger.
[0022] In accordance with an embodiment, an installation element
can be provided for maintaining the distance between two adjacent
sheet elements. The installation element can in particular be
formed as a corrugated, thin-walled spacer element.
[0023] The invention also relates to a method of operating a heat
exchanger in accordance with any one of the preceding embodiments
including a step in which the first fluid is mixed on its flow path
within the sheet element arrangement between its inlet into the
sheet element arrangement and its outlet from the sheet element
arrangement. In accordance with an advantageous variant, the second
fluid flows between adjacent sheet element arrangements in a
cross-flow to the first fluid. The second fluid thus flows
transversely to the first fluid. The first fluid can in particular
be a coolant. The second fluid can in particular be a gas,
advantageously air. The sheet elements can be made as sections in
which the coolant moves in a plurality of separate, parallel
channels. Viewed in the direction of the first fluid, these
channels for the first fluid are disposed after one another.
[0024] The heat transfer differs from one channel to the next
channel for a plurality of reasons. On the one hand, the floating
temperature difference varies due to different local temperatures
of the first fluid; on the other hand, the ratio of liquid phase to
gaseous phase can vary when the second fluid is present in a liquid
phase and in a gaseous phase, which influences the total efficiency
of the heat exchanger.
[0025] More than one cut-out can in particular be arranged in a
sheet element arrangement. When a plurality of cut-outs are
provided, each of the cut-outs can contain a flow-deflecting
element. In particular a mixture of the second fluid can take place
so that a temperature balance occurs in the second fluid and a
homogenization of the temperature profile occurs over the length
and the width of the heat exchanger.
[0026] The performance of a heat exchanger can in particular be
substantially increased when the sheet element arrangements have a
large width and/or length and/or the flow speed of the first fluid
is small.
[0027] A heat exchanger in accordance with the invention can in
particular be built in a larger length and the number of the sheet
arrangements can be reduced by up to two thirds with respect to the
prior art.
[0028] The invention will be explained in the following with
reference to the drawings. There are shown:
[0029] FIG. 1 a view of a sheet element arrangement in accordance
with a first embodiment of the invention;
[0030] FIG. 2 a view of a stack of sheet element arrangements;
[0031] FIG. 3 a side view of an arrangement of sheet elements;
[0032] FIG. 4 a plan view of the arrangement of sheet elements in
accordance with FIG. 3;
[0033] FIG. 5 a detail of the plan view in accordance with FIG.
4;
[0034] FIG. 6 a side view of an arrangement of sheet elements in
accordance with a second embodiment;
[0035] FIG. 7 a plan view of the arrangement of sheet elements in
accordance with FIG. 6;
[0036] FIG. 8 a detail of the side view in accordance with FIG.
6;
[0037] FIG. 9 a view of a stack of sheet elements; and
[0038] FIG. 10 a view of a sheet element arrangement in accordance
with the second embodiment of the invention.
[0039] FIG. 1 illustrates a view of a sheet element arrangement 2
in accordance with a first embodiment of the invention for a heat
exchanger 1. The sheet element arrangement includes a first sheet
element 3, a second sheet element 4 and a cut-out 5 which is
arranged between the first sheet element 3 and the second sheet
element 4. A first fluid 7 enters unto the first sheet element 3,
flows through the openings 6 in the direction of the cut-out 5,
into the cut-out 5, and subsequently leaves the cut-out 5 through
the openings 6 of the second sheet element 4.
[0040] The first fluid 7 is a heat carrier and can be either a
heating medium or a cooling medium. The first fluid 7 is preferably
present in the liquid aggregate state since its heat conductivity
is substantially higher than that of a gaseous fluid and the heat
exchange area available for the first fluid is smaller than for the
second fluid. The openings 6 in the first and second sheet elements
3, 4 have a spacing from one another so that each of the openings 6
forms a channel 9 separate from the other openings and closed at
the jacket side. The channel 9 can in particular have the form of a
tube and/or can be formed as a microchannel having the dimensions
described in the introduction.
[0041] The first fluid 7 flows through these microchannels which
can have corrugated installations which are not shown in the
drawing. These corrugated installations serve for the enlarging of
the heat exchange surface available for the heat transfer. Lattice
structures, mesh-like structures or porous structures can naturally
also be provided instead of the corrugated installations. The
channels 9 can be formed as tubes or also as oval or quadrangular,
in particular rectangular, channels which have been manufactured
from an extruded section by means of an extrusion process. A
plurality of microchannels can hereby be arranged in the sheet
element arrangement. In particular aluminum or an aluminum alloy
has proven itself as a material for the channels 9.
[0042] The first sheet element 3 has a first end 16 which contains
the inlet openings of the openings 6 through which the first fluid
7 is conducted into the first sheet element 3. The outlet openings
of the openings 6 are arranged at a second end 17 of the first
sheet element 3.
[0043] The second sheet element 4 has a first end 18 which contains
the inlet openings of the openings 6 through which the first fluid
7 is conducted into the second sheet element 4. The outlet openings
of the openings 6 are arranged at a second end 19 of the second
sheet element 4.
[0044] In particular in accordance with FIG. 1, the cut-out 5 is
designed so that a plurality of openings 6 at the second end 17 of
the first sheet element 3 open into the cut-out 5 and the first
fluid 7 can in turn be fed from the cut-out 5 into a plurality of
openings which are arranged at the first end 18 of the second sheet
element 4.
[0045] The cut-out is a hollow space which extends between the
first and second sheet elements 3, 4 and which is surrounded by a
jacket element. The cut-out 5 is formed by the second end 17 of the
first sheet element 3, by the first end 18 of the second sheet
element 19 and by the jacket element, with the first sheet element
3 and the second sheet element 4 having a common center plane and
the sheet elements 3, 4 being arranged behind one another with
respect to the flow direction of the first fluid 7.
[0046] In the present representation, the jacket element is made up
of an upper jacket part 10 and a lower jacket part 11. The upper
jacket part 10 is shown in the non-assembled state in the manner of
an exploded drawing so that the structure of the lower jacket part
11 is visible. Instead of an upper and lower jacket part, the
jacket element can also be made in one piece. The first and second
sheet elements can be subsequently connected to the jacket element,
that is, they can, for example, be plugged into openings of the
jacket element for the first and second sheet elements. A
fluid-tight connection between the sheet element is made possible
by a seal element, by a slight oversize of the sheet element
relative to the jacket element or by subsequent welding of the
jacket element and the sheet element.
[0047] The upper jacket part 10 and the lower jacket part 11 have
flow-directing elements 20. The flow-directing elements 20 are
formed as fins 21. Alternatively to this, only one of the upper or
lower jackets parts can naturally have fins 21 and the respective
other one of the upper or lower jacket parts can have a smooth
surface or grooves 23. A plurality of current-directing elements 20
is usually provided, in particular when the heat exchanger has a
large width. However, a single flow-directing element would satisfy
the function of a deflection of the flow of the first fluid 7.
[0048] The flow-directing element 20 can in particular be arranged
at least sectionally at an angle to the channels 9. The
flow-directing element preferably includes an angle with the
channels which is in the range from 10.degree. up to and including
75.degree., preferably in the range from 10.degree. up to and
including 60.degree., particularly preferably in the range from
10.degree. up to and including 45.degree..
[0049] To achieve an improved mixing, the flow-directing elements
20 of the upper jacket part 10 can include a different angle 27
with the channels 9 than the current-directing elements 20 of the
lower jacket part 11. The angle 27 is shown in FIG. 5.
[0050] In accordance with an alternative embodiment, the jacket
element, or at least one of the upper or lower jacket parts 10, 11,
contains projections 25 which project into the cut-out 5 and form
flow disruption elements.
[0051] The cut-out 5 advantageously extends over between 5% and 40%
of the length 26 of the heat exchanger, with the length 26 of the
heat exchanger being measured in the main flow direction of the
first fluid 7 flowing within the sheet elements 3, 4. In FIG. 3,
the length 26 of the heat exchanger is shown as the sum of the
lengths of the sheet elements and of the cut-out 5.
[0052] The cut-out 5 can in particular extend substantially over
the total width 28 of the heat exchanger 1. The width 28 of the
heat exchanger 1 substantially corresponds to the width of the
sheet element arrangement and is shown in FIG. 5.
[0053] FIG. 2 shows a stack of sheet element arrangements 2, 12, 22
which form a heat exchanger 1. These sheet element arrangements 2,
12, 22 are located in a housing which is omitted in the
representation to be able to better illustrate the operation of the
heat exchanger. Each of the sheet element arrangements 2, 12, 22
can be made up of the first and second sheet elements 3, 4 shown in
FIG. 1 as well as of a cut-out 5.
[0054] A second fluid 8, also called a transport fluid, can flow
above and/or beneath each sheet element arrangement 2, 12, 22. The
second fluid 8, which is usually gaseous, can be heated by means of
the heating medium or can be cooled by means of the coolant
depending on the desired function of the heat exchanger 1.
[0055] The intermediate space 15, which is flowed through by the
second fluid 8, can contain installation elements 13 which are
shown as corrugated structures in FIG. 2. The installation elements
13 are in heat conductive contact with the respective adjacent
sheet element arrangements so that heat can be transferred via the
installation elements 13. The installation elements 13 thus also
serve for the increase of the heat exchange surface. The
installation elements can also be formed as fins or, as above,
contain lattice structures, mesh-like structures or porous
structures. Furthermore, the installation elements can also be
formed as serrated sections in V-shape or W-shape.
[0056] FIG. 3 shows a side view of a sheet element arrangement in
accordance with the first embodiment. The thickness of the jacket
element, composed of an upper and lower jacket part 10, 11, in this
respect exceeds the thickness of the first and second sheet
elements 3, 4. This has the consequence that the spacing between
adjacent sheet element arrangements is smaller at the point at
which the jacket element is located. In accordance with the variant
shown in FIG. 10, installation elements 29 are therefore provided
between the jacket elements of adjacent sheet element arrangements
which have a smaller height than the installation elements 13.
[0057] FIG. 4 shows a plan view of the arrangement of sheet
elements in accordance with FIG. 3. The view corresponds to the
arrangement of FIG. 1 when the upper jacket part 10 is removed. The
length of the sheet element arrangement 2 is here defined as the
length of the first and second sheet elements 3, 4 as well as the
length of the cut-out 5 which is not visible here.
[0058] FIG. 5 is a detail of the plan view in accordance with FIG.
4 and shows a part of the lower jacket element 11 as well as the
fins 21 which form the flow-directing element 20. The width 28 of
the sheet element arrangement is likewise shown.
[0059] FIG. 6 shows a side view of a sheet element arrangement in
accordance with a second embodiment of the invention. This sheet
element arrangement differs by the structure of the first and
second sheet elements 3, 4 which have a porous structure through
which the first fluid 7 can flow instead of channels. The cut-out
contains a plurality of projections 25 as flow-directing elements
which can form disruption elements 24 for the flow. These
projections can be local elevated portions or can also be fins or
grooves extending over a part of the length and/or width of the
cut-out.
[0060] FIG. 7 shows a plan view of the arrangement of sheet
elements in accordance with FIG. 6 and has an analog structure to
FIG. 3; see therefore the description of FIG. 3.
[0061] FIG. 8 shows a detail of the side view in accordance with
FIG. 6. The flow-directing elements 20 are formed as fins. The fins
of the upper jacket part and of the lower jacket part come to lie
on one another in the installed state. The first fluid can thus
only flow past these fins and is deflected by the fins and mixed by
the deflection and/or eddying. The temperature drop which the first
fluid has in the direction of the width of the heat exchanger is
thus balanced.
[0062] FIG. 9 shows a view of a stack of sheet elements similar to
FIG. 2. Unlike FIG. 2, the installation elements 29 between the
jacket elements of the cut-outs 5 are also shown which differ in
their height from the installation elements 13 which are arranged
between the sheet elements 3, 4.
[0063] FIG. 10 shows a view of a sheet element arrangement in
accordance with the second embodiment of the invention. The upper
and lower jacket parts 10, 11 are shown as transparent elements so
that the projections are visible which extend cross-wise over a
part of the inner surface of at least one of the jacket parts in
the form of fin pairs.
* * * * *