U.S. patent application number 10/014611 was filed with the patent office on 2002-07-04 for heat exchanger.
Invention is credited to Rittberger, Herbert, Wong, Shui-Wei.
Application Number | 20020084059 10/014611 |
Document ID | / |
Family ID | 4167899 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020084059 |
Kind Code |
A1 |
Rittberger, Herbert ; et
al. |
July 4, 2002 |
Heat exchanger
Abstract
A heat exchanger for exchanging heat between a cooler first air
flow and a warmer second air flow is disclosed. The heat exchanger
comprises a heat exchanger unit having a housing containing a
plurality of heat exchanger plates stacked together to form a
stack. Each heat exchanger plate has four corners and an aperture
located adjacent each comer, the heat exchanger plates being
dimensioned and configured such that the apertures of the heat
exchanger plates overlap to form a first, second, third and fourth
air passageways in the stack. The heat exchanger plates are further
configured to form an alternating series of first and second flat
parallel air chambers in the stack, the first set of air chambers
being continuous with the first and second air passages such that
air can pass between the first and second air passages through the
first set of air chambers, the second set of air chambers being
continuous with the third and fourth air passageways such that air
can pass between the third and fourth air passageways through the
second set of air chambers. The stack of heat exchanger plates are
further configured such that the first and second set or air
chambers are substantially air tight such that air does not leak
between the first and second set of air chambers. The heat
exchanger unit has a first and second side, the first, second,
third and fourth air passageways each having a first end open to
the first side of the heat exchanger unit at a first port and an
opposite second end opened to the second side of the heat exchanger
unit at a second port. The stack is further adapted such that each
port may be selectively plugged by a plug member, the heat
exchanger unit having four plug members, each plug member plugging
one end of each air passageway. Finally, the first, second, third
and fourth air conduits, are each operatively coupled to one of the
air passageways, the air conduits carrying the first and second air
flows.
Inventors: |
Rittberger, Herbert;
(Sturgeon Falls, CA) ; Wong, Shui-Wei;
(Scarborough, CA) |
Correspondence
Address: |
EUGENE J A GIERZAK
KEYSER MASON BALL
201 CITY CENTRE DRIVE
SUITE 701
MISSISSAUGA, ONTARIO
L5B 2T4
CA
|
Family ID: |
4167899 |
Appl. No.: |
10/014611 |
Filed: |
December 14, 2001 |
Current U.S.
Class: |
165/54 ; 165/166;
165/167 |
Current CPC
Class: |
F28F 9/026 20130101;
F28D 9/005 20130101 |
Class at
Publication: |
165/54 ; 165/166;
165/167 |
International
Class: |
F24H 003/02; F28F
003/00; F28F 003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2000 |
CA |
2.328.312 |
Claims
1. A heat exchanger for exchanging heat between a cooler first air
flow and a warmer second air flow, the heat exchanger comprising: a
heat exchanger unit having a housing containing a plurality of heat
exchanger plates stacked together to form a stack, each heat
exchanger plate having four corners and an aperture located
adjacent each corner, the heat exchanger plates dimensioned and
configured such that the apertures of the heat exchanger plates
overlap to form a first, second, third and fourth air passageways
in the stack, the heat exchanger plates further configured to form
an alternating series of first and second flat parallel air
chambers in the stack, the first set of air chambers being
continuous with the first and second air passages such that air can
pass between the first and second air passages through the first
set of air chambers, the second set of air chambers being
continuous with the third and fourth air passageways such that air
can pass between the third and fourth air passageways through the
second set of air chambers, the stack of heat exchanger plates
further configured such that the first and second set or air
chambers are substantially air tight such that air does not leak
between the first and second set of air chambers, the heat
exchanger unit having a first and second side, the first, second,
third and fourth air passageways each having a first end open to
the first side of the heat exchanger unit at a first port and an
opposite second end opened to the second side of the heat exchanger
unit at a second port, the stack being further adapted such that
each port may be selectively plugged by a plug member, the heat
exchanger unit having four plug members, each plug member plugging
one end of each air passageway, first, second, third and fourth air
conduits, each air conduit operatively coupled to one of the air
passageways, the air conduits carrying the first and second air
flows.
2. A heat exchanger as defined in claim 1 wherein the first and
second air passageways are formed on opposite diagonal corners of
the heat exchanger plates, and wherein the third and fourth air
passageways are formed on opposite diagonal corners of the heat
exchanger plates.
3. A heat exchanger as defined in claim 2 wherein the first and
second air conduits are mounted to the first side of the heat
exchanger unit, and the third and fourth air conduits are mounted
to the second side of the heat exchanger unit, the first air
conduit being operatively coupled to two of the ports on the first
side of the heat exchanger unit, the second air conduit being
operatively coupled to the other two ports on the first side of the
heat exchanger unit, the third air conduit being operatively
coupled to two of the ports on the second side of the heat exchange
unit, and the fourth air conduit being operatively coupled to the
other two ports on the second side of the heat exchange unit.
4. A heat exchanger as defined in claim 3 wherein the heat
exchanger further comprises a plurality of substantially identical
heat exchanger units, each heat exchanger unit having its first
side mounted to the first and second air conduits and its second
side mounted to the third and fourth air conduits.
5. A heat exchanger plate for use in forming the heat exchanger
defined by claim 1, the heat exchanger plate comprising; (a) a flat
substantially rectangular sheet having a flat surface, four corners
and a peripheral rim, said rim having a height, (b) a first pair of
apertures formed on the sheet, each opening having a diameter and a
peripheral edge, each aperture positioned adjacent a corner of the
sheet, (c) a pair of collar portions extending perpendicularly from
the sheet, each collar portion positioned adjacent a corner, each
collar portion having a rim defining an opening, each rim having an
outside diameter slightly smaller than the diameter of the first
pair of apertures, (d) the collar portions and the apertures
positioned such that when two such heat exchanger plates are
stacked the rims of the collar portions of one plate extend through
the first pair of apertures of the adjacent heat exchanger plate,
the collar portion being further configured such that the rim
portion may be crimped around the peripheral edge surrounding the
first pair of apertures to form a substantially air tight seal.
6. A heat exchanger plate as defined in claim 5 wherein each collar
portion is formed on the sheet and has a cone shaped base, the base
extending at an acute angle from the surface of the sheet, the base
tapering to form the rim, the rim being substantially cylindrical,
the rim extending from the base at a shoulder.
7. A heat exchanger plate as defined in claim 6 wherein the
peripheral edge surrounding the first pair of apertures makes
contact with the shoulders of the collar portions.
8. A heat exchanger plate as defined in claim 7 wherein the acute
angle is greater than approximately 38.degree..
9. A heat exchange system comprising: (a) a heat exchange unit
adapted to communicate with: (i) a cool air duct; and (ii) a warm
air duct; wherein said heat exchange unit comprises a plurality of
heat exchange panels, the heat exchange panels being adapted to
form a stack of heat exchange panels within the heat exchange unit,
wherein the stack of heat exchange panels is adapted to define: (i)
a first passageway that communicates with said the cool air duct;
and (ii) a second passageway that communicated with the warm air
duct; wherein the first passageway and second passageway are
disposed such that the cool air in the first passageway is adapted
to be heated by the warm air in the second passageway.
Description
FIELD OF THE INVENTION
[0001] The invention relates generally to the field of heat
exchangers for exchanging heat between cold air and heated air.
BACKGROUND OF THE INVENTION
[0002] Countercurrent heat exchangers are well known. They
generally consist of a housing having a plurality of heat exchanger
plates which separate a first flow of fluid from a second flow of
fluid. The heat exchanger plates generally consist of substantially
flat plates which, while keeping the first and second flows
separate, bring both flows in sufficiently close proximity to
permit heat to be exchanged between the two flows.
[0003] Countercurrent heat exchangers are presently used in several
applications, however, their use in residential and commercial
building has been limited by their high cost. Heat exchanger plates
are usually welded or bonded together using expensive and time
consuming techniques. Furthermore, present day heat exchangers are
difficult to integrate into modern forced air heating and air
conditioning systems. Finally, due to their expense and complexity
of design, existing heat exchangers are difficult to customize. in
most cases, a heat exchanger requires the installer little
flexibility in duct positioning; thereby decreasing its appeal to
builders. A simplified, low cost and flexible heat exchanger system
would be easier to sell to the residential and commercial
construction industries.
SUMMARY OF THE INVENTION
[0004] The present invention is a heat exchanger for exchanging
heat between a cooler first air flow and a warmer second air flow.
The heat exchanger comprises a heat exchanger unit having a housing
containing a plurality of heat exchanger plates stacked together to
form a stack. Each heat exchanger plate has four corners and an
aperture located adjacent each comer, the heat exchanger plates
being dimensioned and configured such that the apertures of the
heat exchanger plates overlap to form a first, second, third and
fourth air passageways in the stack. The heat exchanger plates are
further configured to form an alternating series of first and
second flat parallel air chambers in the stack, the first set of
air chambers being continuous with the first and second air
passages such that air can pass between the first and second air
passages through the first set of air chambers, the second set of
air chambers being continuous with the third and fourth air
passageways such that air can pass between the third and fourth air
passageways through the second set of air chambers. The stack of
heat exchanger plates are further configured such that the first
and second set or air chambers are substantially air tight such
that air does not leak between the first and second set of air
chambers. The heat exchanger unit has a first and second side, the
first, second, third and fourth air passageways each having a first
end open to the first side of the heat exchanger unit at a first
port and an opposite second end opened to the second side of the
heat exchanger unit at a second port. The stack is further adapted
such that each port may be selectively plugged by a plug member,
the heat exchanger unit having four plug members, each plug member
plugging one end of each air passageway. Finally, the first,
second, third and fourth air conduits, are each operatively coupled
to one of the air passageways, the air conduits carrying the first
and second air flows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1. Is a perspective view of a heat exchanger of the
present invention.
[0006] FIG. 2. Is a top view of a heat exchanger panel of the
present invention.
[0007] FIG. 3. Is a cross sectional view of the heat exchange panel
shown in FIG. 2 taken along line A-A.
[0008] FIG. 4. Is a long sectional view of the heat exchanger unit
shown in FIG. 1 taken along line B-B.
[0009] FIG. 5. Is a long sectional view of the heat exchanger unit
shown in FIG. 1 taken along line C-C.
[0010] FIG. 6. Is a cross sectional view of a portion of an air
passageway section of a heat exchanger of the present invention
wherein the air passageway has not yet been sealed.
[0011] FIG. 7. Is a cross sectional view of the portion of the heat
exchanger unit shown in FIG. 6 wherein the passageway has been
sealed.
[0012] FIG. 8. Is a top view of an alternate embodiment of the heat
exchanger panel.
[0013] FIG. 9. Is a cross sectional view of the heat exchanger
panel shown in FIG. 8 taken along line F-F.
[0014] FIG. 10. Is a cross sectional view of a portion of an air
passageway section of a heat exchanger in accordance with an
alternate embodiment of the present invention wherein the air
passageway has not yet been sealed.
[0015] FIG. 11. Is a cross sectional view of the portion of the
heat exchanger unit shown in FIG. 10 wherein the passageway has
been sealed.
[0016] FIG. 12. Is a front view of two heat exchangers made in
accordance with the present invention being mounted on the roof of
a building.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring firstly to FIG. 1, a heat exchanger system, shown
generally as item 10, can be used to transfer the heat from the
internal air of a building to the external air outside of the
building as the internal air is exhausted out of the building and
the cooler outside air is vented into the building. A heat
exchanger system made in accordance with the present invention
consists of a heat exchanger unit 12 mounted between exhaust
conduits 14 and intake conduits 16. Exhaust conduit 14 consists of
parallel conduits 18 and 20 while intake conduit 16 consists of
parallel conduits 22 and 24. Heat exchanger 12 consists of a
plurality of heat exchanger units 26, each of which is formed from
a plurality of heat exchanger plates 28. Heat exchanger unit 26 has
conduit 30 for receiving warm stale air from conduit 18. Heat
exchanger plates 28 channels the warm stale air from conduit 30
into opposite conduit 32 located on the other side of the heat
exchanger plates. Air from conduit 32 is exhausted into conduit 20
via a fan or other means known in the art.
[0018] Heat exchanger unit 26 is also provided with conduits 34
which receives air from conduit 24. Air from conduit 34 is
channeled through heat exchanger plates 28 to conduit 36 at the
opposite end of plates 28. Conduit 24 is open to the outside of the
building, and is therefore filled with cooler fresh air. Cooler
fresh air is forced into conduit 24 by a fan or other means and
makes its way into conduit 34. Conduit 34 distributes the cooler
fresh air through plates 28, which exhaust into conduit 36. Conduit
36 in turn exhausts into conduit 22 which supplies the inside of
the building with fresh air. As warm stale air from inside the
building is forced through conduit 18 via a fan or other means, it
passes through conduit 30 and out conduit 32 where it is in turn
passed to conduit 20 and is exhausted out of the building. As the
air passes from conduit 30 to 32, it passes through plates 28.
Likewise, as air passes through conduit 34 to conduit 36, it passes
through plates 28. For the purposes of this patent application, the
air flow from conduit 30 to 32 will be referred to as the outgoing
air flow, and the air flow from conduit 34 to 36 will be referred
to as the ingoing air flow. As will be explained in greater detail,
plates 28 are adapted and configured to separate the ingoing and
outgoing air flows into separate ingoing and outgoing air channels.
These separate air channels are arranged such that the ingoing and
outgoing air flows travel in parallel but opposite directions
through plates 28. As will be explained in greater detail, plates
28 are further configured such that the ingoing and outgoing air
channels are in thermal contact, such that a portion of the heat
contained in the warmer air of the outgoing air channels is
transferred to the cooler air of the ingoing air channel. In this
way, warm stale air from the inside of a building may be used to
heat cold fresh air which is pumped into the building.
[0019] The capacity of heat exchanger plate 10 can be increased
simply by increasing the number of heat exchanger units 26. Hence,
if the heat exchanger capacity of heat exchanger 10 is to be
increased, additional heat exchanger units 26 are mounted between
conduits 14 and 16.
[0020] Referring now to FIG. 2, each heat exchanger plate 28
consists of a substantially flat metal plate having a flat surface
38, opposite ends 40 and 42, and opposite sides 44 and 46. Surface
38 is provided with a pair of apertures 48 and 50 towards opposite
ends 40 and 42. Aperture 50 is provided with corrugated rim 52
which assists in the formation of an air passageway. Preferably,
apertures 48 and 50 located at end 40 are in opposite orientation
to apertures 48 and 50 located towards end 42.
[0021] Referring now to FIG. 3, corrugated rim 52 surrounding
aperture 50 consists of outside wall 58, top 68, middle wall 56,
lower portion 62 and inner wall 60. Inner wall 60, bottom portion
62 and middle wall 56 are formed such that inner gap 64 is created
separating walls 56 and 60. Likewise, outer walls 58 and middle
wall 56 are separated by gap 70. Aperture 48 is defined by
horizontal wall 72 having shoulder 71 and lip 54. Wall 72 is
substantially perpendicular to surface 38. Side 44 forms an angular
wall rising perpendicularly from surface 38. Likewise, side 46
forms an angular wall having top surface 76 rising perpendicularly
from surface 38.
[0022] Turning now to FIGS. 4 and 5, each heat exchanger unit 26 is
formed from a plurality of heat exchanger plates 28 which are
stacked one on top of the other within housing 80 such that
apertures 48 of one heat exchanger plate is alined with aperture 50
of the heat exchanger plate immediately below. Apertures 48 and 50
of heat exchanger plates 28 form air conduits 34, 30, 32 and 36.
Heat exchanger plates 28 also form air chambers 84 and 82 which are
separated by heat exchanger surfaces 38. Due to the sealing
arrangement between apertures 48 and 50, conduit 34 is continuous
with chambers 82 while conduit 30 is continuous with chambers 84.
Conduit 34 is sealed at one end by cap 96 and conduit 30 is sealed
at one end by cap 90. As air travels through conduit 34 it travels
through air chambers 82 and out of air conduit 36. Likewise, as air
travels through conduit 30 it travels into chambers 84 and out of
conduit 32. Surfaces 38 of heat exchanger plates 28 separate the
air flow in chambers 82 and 84. It will be appreciated that the air
in chamber 82 is flowing in a parallel but opposite direction to
the air in chambers 84. Since heat exchanger plates 28 are made of
aluminum or sheet metal or some other such material, heat is
exchanged between chambers 82 and 84 in a counter flow
arrangement.
[0023] One of the advantages of the present heat exchanger plate
design is that by simply capping different apertures, a different
pattern of air flow can be created in the heat exchanger unit. For
example, considering the embodiment shown in FIGS. 4 and 5, heat
exchanger unit 12 has eight possible ports through which air may
pass into or out of the heat exchanger unit. In particular, heat
exchanger unit 12 has ports 86a, 86b, 92a, 92b, 94a, 94b, 88a and
88b. These ports can either be left opened or closed, depending on
the particular air flow pattern desired. In the particular example
shown in FIGS. 4 and 5, ports 86a, 92b, 88a and 94b are left open,
while ports 92a, 86b, 94a and 88b are closed off by caps 90 and 96.
This particular arrangement of open and closed ports permits a
first airflow D between ports 86a and 88a and a second air flow E
between ports 94b and 92b. If first airflow D represents the
ingoing air flow and second airflow E represents the outgoing air
flow, then cold fresh air would flow into port 86a, pick up heat
from airflow E and then exhaust as warmer fresh air out of port
88a. Likewise, warmer stale air would enter port 92b, exchange its
heat with air flow D, and exhaust as cooler stale air out port 94b.
By capping different ports, a different air flow pattern can be
created. For example, by capping ports 88a and 94b and opening
ports 88b and 94a, a different counter current air flow pattern is
created.
[0024] It will be appreciated that depending on the needs of the
customer, certain air flow patterns may be more desirable than
others. The particular arrangement shown in FIG. 1 shows fresh air
being carried by conduits 24 and 22 of intake conduits 16 while
stale air is carried in conduits 18 and 20 of exhaust conduit 14.
In some applications, this particular arrangement may not be
optimal since there will be a temperature difference between
conduits 24/22 and conduits 18/20. in some applications, this may
result in condensation build up. If condensation buildup is a
problem, it may be preferable to keep both of the "warm" air flows
together in the same intake or exhaust conduit. The versatility of
the present design permits each heat exchanger unit to be
customized to meet particular applications. All that is required to
alter the internal air flow pattern is a number of caps 90 and 96.
In this way, each heat exchanger can be tailored to the specific
needs of the customer.
[0025] Referring now to FIG. 6, the method of sealing heat
exchanger plates 28 will now be disclosed. The inside diameter of
aperture 48 is selected such that lip 72 of first heat exchanger
plate 98 can fit between middle wall 56 and inner wall 60 of lower
heat exchanger plate 100. Surfaces 38 of heat exchanger plates 98
and 100 define chamber 102. The height of walls 58 and 56 define
the height of chamber 102. Outer wall 58 and middle wall 56 form a
rigid annular structure which supports heat exchanger plate 98.
Aperture 48 is dimensioned such that lip 72 fits within gap 64
defined by middle wall 56 and inner wall 60 of heat exchanger plate
100. Inner wall 60 is dimensioned such that lip 66 projects above
surface 38 of heat exchanger plate 98.
[0026] As seen in FIG. 7, plate 98 and 100 are sealed together such
that relatively little air leaks from chamber 102 into aperture 50.
The sealing is accomplished by deforming inner wall 60 and adjacent
lip 66 such that lip 66 makes contact with shoulder 71 of upper
heat exchanger plate 98. To ensure that lip 66 makes contact with
shoulder 71 all along the periphery of aperture 50, lip 72 is
selected to be sufficiently long such that rim 54 of lip 72 makes
contact with lower portion 62 of lower heat exchanger plate 100.
This structure permits lip 72 to resist the force of the tool which
is used to deform edge 66 against shoulder 71. It has been
discovered that if edge 54 of lip 72 does not make contact with
bottom portion 62, then a tight seal between shoulder 71 and edge
66 is less likely to occur.
[0027] An alternate embodiment of the heat exchanger plates of the
present invention is shown in FIGS. 8, 9, 10 and 11. The alternate
embodiment essentially consists of an alternate structure for the
sealing of the heat exchanger plates. As seen in FIG. 8, heat
exchanger plate 150 consists of a substantially flat metal plate
having flat surface 152 opposite ends 154 and 156 and opposite
sides 158 and 160. Flat surface 152 is provided with a pair of
apertures 162 and 164 toward end 154 and apertures 166 and 168
toward end 156. Apertures 164 and 166 are provided with rim 170 and
172, respectively.
[0028] Referring now to FIG. 9, rim 172 consists of a cone like
base 176 surrounding a cylindrical collar 174. Base 176 is at an
angle (alpha) relative to flat surface 152. Collar 174 is at an
angle beta to base 176. It will be appreciated that base 176
consists of a cone-like base extending outwardly from collar 174.
Collar 174 has an upper rim 182 which defines the diameter of
opening 166. Base 176 and collar 174 are dimensioned such that rim
182 projects above ledges 178 and 180. Aperture 162 is formed on
flat surface 152 as a simple aperture having rim 176. The diameter
of aperture 162 is slightly higher than the outside diameter of
collar 174. Preferably, aperture 162 is approximately 20 thousandth
in radius larger than the outside diameter of collar 174.
[0029] Referring now to FIGS. 10 and 11, heat exchanger plates 150
can be stacked one on top of the other as in the previous
embodiment. When heat exchange plates 150 are stacked one on top of
the other, a plurality of parallel air chambers 188 and 190 are
formed. An air passage way connecting air chambers 190 is formed by
openings 166, and base 176. Collar portion 174 of a lower heat
exchanger plate is inserted into aperture 162 of a corresponding
upper heat exchanger plate such that collar portion 174 pass
through aperture 162, as shown in FIG. 10. To seal the gap
separating rim 196 from collar 174, collar 174 is bent around rim
196 as shown in FIG. 11. Angle alpha is selected to ensure that
collar 174 can be deformed to seal aperture 162 without causing
flat surfaces 152 to deform. It has been discovered that if angle
alpha equals 38 degrees or less, and if collar 174 is approximately
0.03 inches in height between rim 182 and point 184 where the
collar meets base 176, then wall 174 may be bent around rim 196 of
aperture 162 without causing any significant deformation of flat
surface 152. Experiments using aluminum 50-52 sheeting having a
thickness of 0.02 inches, showed that an angle alpha of 38 degrees
permitted tight sealing of aperture 162 without significant
buckling of surface 152. By contrast, when Alpha angles of 40
degrees or 42 degrees were attempted, significant buckling of flat
surface 152 occurred. Furthermore, where alpha was greater than 38
degrees, very poor ceiling around rim 196 was obtained.
[0030] As mentioned previously, one of the advantages of the
present invention is how the air flow patterns in the heat
exchanger can be modified to suit the particular needs of the
customer. This is particularly evident when two heat exchangers are
to be coupled for high volume applications. Referring now to FIG.
12, if building 200 requires a higher capacity of fresh air
ventilation, then two heat exchangers, 104 and 106 may be mounted
to roof 202. In order to ensure that only one hole is made in the
roof to accommodate the exhaust ducts, exhaust conduit 108 of heat
exchanger 106 and exhaust conduit 110 of heat exchanger 104 can be
arranged such that the two exhaust conduits are side by side. This
side by side arrangement permits the exhaust conduits of both heat
exchangers 104 and 106 to be coupled to the same exhaust fan (not
shown), thereby simplifying the installation of the units.
[0031] Specific embodiments of the present invention have been
disclosed; however, several variations of the disclosed embodiments
could be envisioned as within the scope of this invention. It is to
be understood that the present invention is not limited to the
embodiments described above, but encompasses any and all
embodiments within the scope of the following claims.
* * * * *