U.S. patent application number 12/528596 was filed with the patent office on 2010-05-13 for heat exchanger of crossflow type.
This patent application is currently assigned to AIREC AB. Invention is credited to Sven Persson.
Application Number | 20100116479 12/528596 |
Document ID | / |
Family ID | 39635407 |
Filed Date | 2010-05-13 |
United States Patent
Application |
20100116479 |
Kind Code |
A1 |
Persson; Sven |
May 13, 2010 |
Heat exchanger of crossflow type
Abstract
The invention relates to a heat exchanger (1) of crossflow type
for heat exchange between different media, which heat exchanger (1)
comprises a plate stack (2) of heat transfer plates for first and
second plate types (3, 4). The plate types (3,4) are stacked 5
alternately on one another in the plate stack (2). Each plate type
(3, 4) has a side A and a side B with a heat exchange surface (9).
The heat exchange surface (9) comprises a pattern (10a, b). In the
plate stack (2), adjacent plate types (3, 4) form both first
throughflow ducts (14) and second throughflow ducts (15). Said
first throughflow ducts (14) have a larger volume than said second
throughflow ducts (15), the volume of a first medium (16) in said
10 first throughflow ducts (14) being greater than the volume of a
second medium (17) in said second throughflow ducts (15). Said
media (16, 17) are subject to heat transfer between them through
the heat exchange surface (9) between the ducts (14, 15), the
pressure drop of medium (16) flowing through the first throughflow
duct (14) being less than the pressure drop of medium (17) flowing
through the second throughflow duct (15).
Inventors: |
Persson; Sven; (Limhamn,
SE) |
Correspondence
Address: |
Mollborn Patents, Inc.
2840 Colby Drive
Boulder
CO
80305
US
|
Assignee: |
AIREC AB
Malmo
SE
|
Family ID: |
39635407 |
Appl. No.: |
12/528596 |
Filed: |
March 3, 2008 |
PCT Filed: |
March 3, 2008 |
PCT NO: |
PCT/SE08/50234 |
371 Date: |
August 25, 2009 |
Current U.S.
Class: |
165/166 ;
165/170 |
Current CPC
Class: |
F28D 1/0341 20130101;
F28D 9/0043 20130101; F28F 3/044 20130101 |
Class at
Publication: |
165/166 ;
165/170 |
International
Class: |
F28F 3/04 20060101
F28F003/04; F28D 9/00 20060101 F28D009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2007 |
SE |
0700570-5 |
Claims
1. A heat exchanger (1) of crossflow type for heat exchange between
different media, comprising a plate stack (2) which itself
comprises a number of heat transfer plates of a first plate type
(3) and of a second plate type (4), which plate types (3, 4) are
stacked alternately on one another in the plate stack (2) and each
have two opposite long sides (5a, b), two opposite short sides (6a,
b), first and second portholes (7, 8) disposed close to a short
side (6a), a side A which has a heat exchange surface (9), a side B
comprising the other side of said heat exchange surface (9), which
heat exchange surface (9) has a pattern (10a, b) comprising a
portion with dimples (11) and is disposed between the long and
short sides (5a, b, 6a, b), which heat exchange surface (9) of each
plate type (3, 4) is disposed between first and second planes (12,
13), whereby side A of a first plate type (3) is connected and
adjacent to side B of a second plate type (4) in a first plane (12)
between adjacent plate types (3, 4) forming a first throughflow
duct (14), and side B of a first plate type (3) is connected to
side A of a second plate type (4) in a second plane (13) between
adjacent plate types (3, 4) forming a second throughflow duct (15),
characterised in that said first throughflow duct (14) has a larger
volume than said second throughflow duct (15), whereby the volume
of a first medium (16) in said first throughflow duct (14) is
greater than the volume of the second medium (17) in said second
throughflow duct (15), which said media (16, 17) are subject to
heat transfer between them through the heat exchange surface (9)
between the ducts (14, 15), the pressure drop of the medium (16)
flowing through the first throughflow duct (14) being smaller than
the pressure drop of the medium (17) flowing through the second
throughflow duct (15).
2. A heat exchanger (1) according to claim 1, characterised in that
round each porthole (7, 8) in the first plate type (3) a first edge
region (18) is disposed in the first plane (12) and constitutes an
abutment surface against a second edge region (19) disposed round
each porthole (7, 8) of the second plate type (4), which second
plate type (4) is disposed on the first plate type (3) in the plate
stack (2), whereby side A of the first plate type (3) is connected
and adjacent to side B of the second plate type (4).
3. A heat exchanger (1) according to claim 1, characterised in that
a divider (20), preferably stamped, is disposed in the heat
exchange surface (9) of one plate type (3, 4), preferably the first
plate type, and extends from the short side (6a) where said
portholes (7, 8) are situated towards the second short side (6b),
which divider (20) is shorter than said long sides (5a, b), is
disposed between them and is disposed parallel between said long
sides (5a, b).
4. A heat exchanger (1) according to claim 3, characterised in that
the divider (20) of the first plate type (3) comprises a ridge (21)
or bottom (21) situated in the second plane (13) on side B of the
first plate type (3), whereby the divider (20) is connected to side
A of an adjacent second plate type (4), thereby forming between two
plate types (3, 4) a passage between a free end (22) of the divider
(20) and a short side (6b) of the plate types (3, 4).
5. A heat exchanger (1) according to claim 1, characterised in that
the first throughflow duct (14) is disposed between respective long
sides (5a, b) and between two adjacent plate types (3, 4) which are
connected to one another in said first plane (12).
6. A heat exchanger (1) according to claim 1, characterised in that
the second throughflow duct (15) is disposed in the second plane
(13) and extends between said ports (7, 8), whereby said second
throughflow duct (15) extends from the first short side (6a)
situated adjacent to the first porthole (7) towards the second
short side (6b) between the divider (20) and one long side (5a),
through the passage between the free end (22) of the divider (20)
and the second short side (6b) towards the first short side (6a)
between the second side of the divider (20) and the other long side
(5b), which first short side (6a) is also adjacent to the second
porthole (8), whereby said second throughflow duct (15) thus
extends in a U shape from the first porthole (7) round the divider
(20) and back on the other side of the divider (20) to the second
porthole (8).
7. A heat exchanger (1) according to claim 1, characterised in that
a third edge region (23) of the first plate type (3) is disposed in
the second plane (13) of the first plate type (3) and extends round
said plate type (3) both along each long side (5a, b) and along
each short side (6a, b), which edge regions (23) constitute an
abutment surface against the edge regions (23) of the second plate
type (4) which are disposed on the second plate type (4) in a
corresponding manner, which second plate type (4) is placed under
the first plate type (3) in the plate stack (2).
8. A heat exchanger (1) according to claim 1, characterised in that
each plate type (3, 4) has a rim (24) disposed on each short side
(6a, b).
9. A heat exchanger (1) according to claim 1, characterised in that
a number of distribution ducts (26 a-d) are disposed in a region
where the dimples (11) are adjacent to the edge region (18, 19) of
a porthole (7, 8), whereby said distribution ducts (26 a-d)
communicate with the respective portholes (7, 8) to which the
respective distribution ducts (26 a-d) lead.
10. A heat exchanger (1) according to claim 8, characterised in
that a draining duct (25) is disposed in the rim (24) or in the
immediate vicinity of the rim (24) and communicates with
throughflow ducts (14, 15) formed between two adjacent plate types
(3, 4).
11. A heat exchanger (1) according to claim 1, characterised in
that the configuration of the pattern (10a, b) of dimples (11) of
the first plate type (3) is such that the peaks of two adjacent
dimples (11) which point in the same direction have, disposed
between them at a level below the peaks, a valley situated higher
than the bottoms of two other adjacent dimples (11), which bottoms
point in the opposite direction from that of the peaks.
12. A heat exchanger (1) according to claim 1, characterised in
that the dimples (11) of the second plate type (4) point on side A
from the second plane (13) towards the first plane (12).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a heat exchanger of
crossflow type for heat exchange between different media according
to the preamble of claim 1.
BACKGROUND TO THE INVENTION
[0002] European patent specification EP 0984239 B1 refers to a heat
exchanger of crossflow type. The heat exchanger according to EP
0984239 B1 is composed of two plate types placed alternately on one
another to form a plate stack. Ducts are disposed between two
adjacent plates. The heat exchanger is adapted to receiving two
media for heat transfer between the two media. The ducts all have
substantially the same volume as one another. The fact that media
may differ in density makes it impossible to utilise heat exchange
between two media effectively enough when the respective ducts have
the same volume.
SUMMARY OF THE INVENTION
[0003] An object of the present invention is to provide a heat
exchanger capable of maximum and optimum heat transfer between two
media which flow in two ducts and are subject to heat transfer
through a duct wall.
[0004] A further object of the invention is to provide a device and
a method which are cost-effective compared with the state of the
art, which device is easy to construct, thereby making it possible
to optimise cost and time.
[0005] The aforesaid and other objects are achieved according to
the invention by the device described in the introduction having
the characteristics indicated in claim 1.
[0006] An advantage achieved with a device according to the
characterising part of claim 1 is that optimum heat transfer
between two different media of different densities becomes
possible.
[0007] Preferred embodiments of the device according to the
invention further have the characteristics indicated in subclaims
2-12.
[0008] According to an embodiment of the invention, a first edge
region in the first plane is disposed round respective portholes in
the first plate type and constitutes an abutment surface against a
second edge region disposed round respective portholes in the
second plate type, which second plate type is disposed on the first
plate type in the plate stack, whereby side A of the first plate
type is connected and adjacent to side B of the second plate type.
A first throughflow duct is thus formed between two adjacent plate
types.
[0009] According to a further embodiment of the invention, a
divider, preferably stamped or pressed, is disposed in the heat
transfer surface of one plate type, preferably the first plate
type, and extends from the short side where said portholes are
situated towards the other short side, which divider is shorter
than said long sides and is disposed between them and disposed
parallel between said long sides. An advantage of a divider in a
plate type in a heat exchanger is that it stiffens the structure of
the plate stack.
[0010] According to a further embodiment of the invention, the
divider in the plate comprises a ridge or bottom situated in the
second plane on a side B of the first plate type, whereby the
divider is connected to side A of an adjacent second plate type,
thereby forming between two plate types a passage between the free
end of the divider and a short side of the plate types. Said ridge
or bottom of the divider has a contact surface connecting to the
adjacent second plate type. The connection between two plate types
is by technology already known to one skilled in the art, e.g.
soldering, welding, adhesive, bonding etc.
[0011] According to a further embodiment of the invention, the
first throughflow duct is disposed between respective long sides
and disposed between two adjacent plate types which are connected
to one another in said first plane. As previously mentioned, the
divider extends from the first plane towards the second plane on a
side B of a first plate type. This means that on side A of the
first plate type the divider does not protrude from the surface and
has no effect on a flow on the side of the first plate type. As
previously mentioned, side A of a first plate type is connected to
side B of a second plate type, thereby forming said first
throughflow duct between said plate types. As the divider does not
affect the flow in the first throughflow duct, the duct may be
disposed between respective long sides of said adjacent plate
types.
[0012] According to a further embodiment of the invention, the
second throughflow duct is disposed in the second plane and extends
between said ports, whereby said second throughflow duct extends
from the first short side situated adjacent to the first port
towards the second short side between the divider and one long
side, through the passage disposed between the free end of the
divider and the second short side, and towards the first short side
between the second side of the divider and the second long side,
which first short side is also adjacent to the second port, whereby
said second throughflow duct thus extends in a U shape from the
first port round the divider and back on the second side of the
divider to the second port. The throughflow duct extending in a U
shape results in a longer flow path for the medium in the second
throughflow duct.
[0013] According to a further embodiment of the invention, the
third edge region of the first plate type is disposed in the second
plane of the plate type and extends round said plate type both
along each long side and along each short side, which edge regions
constitute an abutment surface against the edge region of the
second plate type which on the second plate type is disposed in a
corresponding manner, which second plate type is placed under the
first plate type in the plate stack. Side B of the first plate type
connects to side A of the second plate type in a second plane, thus
forming said second throughflow duct. This duct thus has an inlet
via the first porthole and an outlet via the second porthole.
[0014] According to a further embodiment of the invention, each
plate type has a rim disposed on each short side. The rim
constitutes an abutment surface adapted to connecting to an
adjacent plate type in the plate stack.
[0015] According to a further embodiment of the invention, a number
of ducts are disposed in a region where the dimples are adjacent to
the edge region of a port, whereby said ducts communicate with the
porthole to which the ducts lead. The ducts help to lead medium out
from the port to regions of the respective plate type to which it
is difficult to cause distribution of a medium. Rendering these
regions easier for a medium to reach may result in better
utilisation of the total heat exchange surface of the respective
plate type, through the medium being caused to spread and be
distributed over a larger area of the heat exchange surface because
the ducts lead part of the medium to regions of the heat exchange
surface to which access is difficult.
[0016] According to a further embodiment of the invention, a
draining duct is disposed in the rim, or in the immediate vicinity
of the rim, and communicates with ducts formed between two adjacent
plates. The draining duct takes the form of a hole arranged through
a plate type. The draining duct communicates with the first
throughflow duct. In the first throughflow duct, medium may be
stationary during operation at the short end of two connected plate
types. This is because part of a medium which flows through first
throughflow ducts between long sides of the plate types may remain
between the plate types, e.g. because the medium condenses. Hence
the need for a draining duct which can lead superfluous or
stationary medium away from the heat exchanger.
[0017] According to a further embodiment of the invention, the
configuration of the pattern of dimples in the first plate type is
such that the peaks of two adjacent dimples pointing in the same
direction have, disposed between them at a level below the peaks, a
valley situated higher than the bottoms of two other adjacent
dimples, which bottoms point in the opposite direction from that of
the peaks. The dimples contribute to the heat exchange surface
being larger than if it was flat.
[0018] According to a further embodiment of the invention, the
dimples of the second plate type point on side A from the second
plane towards the first plane. On side A of said second plate type
in the second plane, flat regions are disposed between the dimples.
These flat regions constitute an abutment surface for peaks of
dimples belonging to the first plate type which connects to the
second plate type. On side A of the second plate type, the flat
regions are so disposed that a peak portion of the divider on a
second plate type can be placed against said regions and be
connected to them.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A preferred embodiment of the device according to the
invention is described below in more detail with reference to the
attached schematic drawings, which only show the parts needed for
understanding the invention.
[0020] FIG. 1 depicts a view of a plate stack for a heat
exchanger.
[0021] FIG. 2 depicts a view of the plate stack where the
constituent plate types parted from one another for the sake of
clarity.
[0022] FIG. 3 depicts a view of a first plate type.
[0023] FIG. 4 depicts a section through the first plate type.
[0024] FIG. 5 depicts a view of a second plate type.
[0025] FIG. 6 depicts a section through the second plate type.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION
[0026] FIG. 1 depicts a heat exchanger (1) comprising a plate stack
(2). The plate stack (2) is made up of a number of heat transfer
plates, some comprising a first plate type (3) and some a second
plate type (4).
[0027] The heat exchanger (1) according to FIG. 1 is of crossflow
type. The plate types (3, 4) are so disposed in the heat exchanger
(1) that their long sides (5a, b) are open, whereby a medium can
flow through the heat exchanger (1) from a long side (5a) to
another long side (5b). Short sides (6a, b) are with advantage
connected to one another between adjacent plate types (3, 4).
[0028] FIG. 2 depicts a view of the plate stack (2) where the plate
types (3, 4) are separated from one another in order to make clear
their positions and how respective media flow between respective
pairs of plates. FIG. 2 shows the plate stack (2) made up of two
plate types (3, 4) stacked alternately on one another. Each plate
type (3, 4) has first and second portholes (7, 8). Said portholes
(7, 8) are situated near a short side (6a) of the respective plate
type. Each plate type (3, 4) has a heat exchange surface (9). Said
heat exchange surface (9) has a pattern (10a, b) comprising a
number of dimples (11). The configuration of the dimples differs
between the respective plate types (3, 4). This is explained in
more detail below. FIG. 2 illustrates how the respective media flow
through the heat exchanger (1). It shows clearly that the flows
cross one another in the heat exchanger (1), hence the name heat
exchanger of crossflow type.
[0029] FIG. 3 depicts a first plate type (3). The pattern (10a) of
the first plate type (3) extends between a first plane (12) and a
second plane (13). This is illustrated in FIG. 4, which depicts a
section through the first plate type (3) parallel with the short
sides (6a, b) and through the respective portholes (7, 8). The
first plate type has a side A and a side B. In FIG. 3, side A is
the side of the first plate type (3) which is visible to the
reader. Side B constitutes the underside of the first plate type
(3) in FIG. 3.
[0030] FIG. 5 depicts a second plate type (4). The pattern (10b) of
the second plate type (4) extends in a manner corresponding to that
of the first plate type (3) between second and first planes (13,
12). Upon abutment between two plate types (3, 4) which constitute
a pair of plates, the planes (12, 13) of a pair of plates coincide.
This means that in a plate pair it is possible, for example, for
the two plate types to relate to either of the planes (12, 13). The
first and second planes (12, 13) of the second plate type (4) are
illustrated in FIG. 6, which depicts a section through the second
plate type (4) parallel with the short sides (6a, b) and through
the respective portholes (7, 8). The second plate type has a side A
and a side B. In FIG. 5, side A is the side of the second plate
type (4) which is visible to a reader. Side B constitutes the
underside of the second plate type (4) in FIG. 5.
[0031] In the plate stack, side A of the first plate type (3) forms
together with side B of the adjacent second plate type a first
throughflow duct (14, see FIG. 2). Side B of the first plate type
(3) and side A of the second plate type form together a second
throughflow duct (15, see FIG. 2). A first medium (16) flows in the
first throughflow duct (14). A second medium (17) flows in the
second throughflow duct (15). Said first and second media (16, 17)
are subject to heat exchange between them through the respective
plate types (3, 4).
[0032] The first plate type (3) has round each porthole a first
edge region (18, see FIGS. 3, 4). This first edge region (18) is
situated in the first plane (12) of the plate type (3). Said first
edge region (18) has the function of an abutment surface. This is
because the first edge region (18) is adapted to abutting against a
second edge region (19). This second edge region (19) is situated
round the respective portholes of an adjacent second plate type (4,
see FIGS. 5, 6) in the plate stack (2). Said second edge region
(19) is situated in the first plane (12) of the second plate type
(4). Upon abutment between the two plate types (3, 4) said edge
regions (18, 19) coincide and are adjacent to one another in the
same first plane (12). The short sides (6a, b) of said adjacent
plate types (3, 4) are with advantage connected to one another in
the first plane (12). The first throughflow duct (14) is disposed
between said adjacent plate types (3, 4, see FIG. 2).
[0033] A divider (20) is disposed in the first plate type (3, see
FIG. 3). This divider (20) is with advantage pressed or stamped in
the first plate type (3). Alternatively a separate divider may be
fitted permanently to the heat exchange surface (9) of the first
plate type (3). The divider (20) extends from one short side (6a)
towards the other short side (6b) between and parallel with the
long sides (5a, b) and between the portholes (7, 8). The divider
(20) has a bottom (21) situated in the second plane (13) of the
first plate type (3, see FIG. 4).
[0034] Said divider (20) with its bottom (21) on side B of the
first plate type (3) is adapted to abutting against a side A of the
second plate type (4). As previously mentioned, upon contact
between side B of a first plate type (3) and side A of a second
plate type (4) the bottom (21) of the divider (20) connects to side
B of said second plate type (4). The long sides (5a, b) and short
sides (6a, b) of adjacent plate types (3, 4) connect to one another
with advantage in the second plane (13). The divider (20) is
shorter than the long sides (5a, b). The divider (20) has a free
end (22). The fact that the divider (20) is shorter than the long
sides (5a, b) results in there being a passage between the free end
(22) of the divider (20) and the other short side 6b between side B
of a first plate type (3) and side A of a second plate type (4).
The second throughflow duct (15) is disposed between said plate
types (3, 4). The first porthole (7) communicates with the second
porthole (8) via a medium which flows in the second throughflow
duct (15).
[0035] A third edge region (23) extends along the respective long
sides (5a, b) and short sides (6a, b) of both the first and second
plate types (3, 4). This third edge region (23) is situated in the
second plane (13) of the respective plate types (3, 4). The
respective third edge regions (23) of the respective plate types
(3, 4) are adapted to abutting against and being connected to one
another.
[0036] A rim (24) is disposed on the respective short sides (6a, b)
of the respective plate types (3, 4). The respective rims (24) on
respective adjacent plate types (3, 4) are so disposed that the
rims (24) can abut against and be connected to one another. A
draining duct (25) is disposed in the rim (24) along the second
short side (6b) of the first plate type (3, see FIG. 3). The
draining duct (25) takes the form of a hole through the rim (24) of
the first plate type (3). It is thus possible to remove via the
draining duct (25) any medium remaining in a plate pair, e.g. as a
result of condensation. In an alternative embodiment (not shown in
the figures) the respective short sides between adjacent plates in
the plate stack are open, whereby adjacent rims on the short sides
do not seal against each other.
[0037] A number of distribution ducts (26 a-d, see FIG. 5) situated
in the second plate type (4) extend from the respective first and
second edge regions (14, 15) round the respective portholes (7, 8)
to a number of dimples situated round said portholes (7, 8) in the
heat exchange surface (9). The distribution ducts (26 a-d) lead
medium from the ports (7, 8) to the parts of the heat exchange
surface (9) which are difficult for the flow to reach. The
distribution ducts (26 a-d) are pressed or stamped in the second
plate type (4).
[0038] The dimples of the first plate type (3) differ in
configuration from the dimples of the second plate type (4). The
result in each throughflow duct (14, 15) is duct surface
irregularity which helps to increase the turbulence of a medium
flowing through said throughflow ducts (14, 15).
[0039] The invention is not limited to the embodiment referred to
but may be varied and modified within the scopes of the claims set
out below, as partly described above.
* * * * *