U.S. patent application number 11/148394 was filed with the patent office on 2006-07-27 for heat exchanger assembly.
This patent application is currently assigned to International Mezzo Technologies, Inc.. Invention is credited to Kevin W. Kelly, Patrick S. Luke, Kevin P. McCoy.
Application Number | 20060162910 11/148394 |
Document ID | / |
Family ID | 36695491 |
Filed Date | 2006-07-27 |
United States Patent
Application |
20060162910 |
Kind Code |
A1 |
Kelly; Kevin W. ; et
al. |
July 27, 2006 |
Heat exchanger assembly
Abstract
An apparatus providing high efficiency heat exchange between two
fluids is disclosed. The apparatus most commonly comprises multiple
thin panels with fluid channels directing the flow of the two
fluids, specifically: one or more flat panels aligned at some angle
to the flow of the fluid traveling through the shortest channel of
the thin panels. The panels are arranged in series and parallel, so
that the hot fluid travels through multiple thin panels. The
coolant is delivered to the thin panels through tubes or manifolds
while the hot fluid is delivered through a duct or other
piping.
Inventors: |
Kelly; Kevin W.; (Baton
Rouge, LA) ; Luke; Patrick S.; (Baton Rouge, LA)
; McCoy; Kevin P.; (Baton Rouge, LA) |
Correspondence
Address: |
ANTHONY P. IANNITELLI;INTERNATIONAL MEZZO TECHNOLOGIES, INC.
7167 FLORIDA BLVD.
BATON ROUGE
LA
70806
US
|
Assignee: |
International Mezzo Technologies,
Inc.
|
Family ID: |
36695491 |
Appl. No.: |
11/148394 |
Filed: |
June 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11041767 |
Jan 24, 2005 |
|
|
|
11148394 |
Jun 8, 2005 |
|
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Current U.S.
Class: |
165/148 |
Current CPC
Class: |
F28F 7/02 20130101; F28D
7/1615 20130101; F28D 7/0008 20130101 |
Class at
Publication: |
165/148 |
International
Class: |
F28D 1/00 20060101
F28D001/00 |
Claims
1. A heat exchanger for transferring heat between a first fluid and
a second fluid, comprising: a. A core made up of one or more thin
panel heat exchangers; and b. An apparatus for directing the first
fluid to the core, such as tubes or an integrated manifold; and c.
An apparatus for directing the second fluid to the core, such as
ducts or piping.
2. The heat exchanger of claim 1 in which the core is made up of
more than one thin panel heat exchanger.
3. The heat exchanger of claim 2 in which the thin panels are in
series such that the second fluid flow must pass through each panel
successively.
4. The heat exchanger of claim 3 in which the series of thin panels
in the core are placed so that the second fluid flow impinges the
panels normal to their largest face.
5. The heat exchanger of claim 4 in which the series of thin panels
in the core are aligned so that the second fluid flow channels
match up in successive panels.
6. The heat exchanger of claim 4 in which the series of thin panels
in the core are aligned so as to stagger the inlets of the second
fluid flow channels.
7. The heat exchanger of claim 3 in which the series of thin panels
in the core are placed to that the second fluid flow impinges the
panels at some angle other than normal to their largest face.
8. The heat exchanger of claim 7 in which the series of thin panels
in the core are aligned so that the second fluid flow channels
match up in successive panels.
9. The heat exchanger of claim 7 in which the series of thin panels
in the core are aligned so as to stagger the inlets of the second
fluid flow channels.
10. The heat exchanger of claim 2 in which the thin panels in the
core are arranged in parallel such that the second fluid flow may
pass through any of the panels.
11. The heat exchanger of claim 10 in which the thin panels in the
core are arranged so that the second fluid flow impinges the panels
normal to their largest face.
12. The heat exchanger of claim 10 in which the thin panels in the
core are placed so that the second fluid flow impinges the panels
at some angle other than normal to their largest face.
13. The heat exchanger of claim 12 in which the thin panels are
placed in a corrugated arrangement which results in a series of
v-shapes.
14. The heat exchanger of claim 2 in which the core is made up of
thin panels placed in a series and parallel configuration.
15. The heat exchanger of claim 14 in which the core is a stack
made up of multiple v-shapes in series.
16. The heat exchanger of claim 14 in which the core is made up of
multiple stacks of v-shapes in parallel.
17. The heat exchanger of claim 2 in which the thin panels contain
microchannels.
18. The heat exchanger of claim 14 in which the thin panels contain
microchannels.
19. The heat exchanger of claim 15 in which the thin panels contain
microchannels.
20. The heat exchanger of claim 16 in which the thin panels contain
microchannels.
21. The heat exchanger of claim 2 also comprising some additional
material attached to the thin panels so as to provide secondary
heat transfer surfaces for the second fluid, such as fins, pins or
expanded foam.
22. The heat exchanger of claim 14 in which the thin panels have
secondary heat transfer surfaces for the second fluid, such as
fins, pins or expanded foam.
23. The heat exchanger of claim 15 in which the thin panels have
secondary heat transfer surfaces for the second fluid, such as
fins, pins or expanded foam.
24. The heat exchanger of claim 16 in which the thin panels have
secondary heat transfer surfaces for the second fluid, such as
fins, pins or expanded foam.
25. The heat exchanger of claim 21, in which the secondary heat
transfer surfaces are arrayed so as to control the distribution of
flow for the second fluid through the thin panel.
Description
REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a continuation-in-part of co-pending
application identified as U.S. patent application Ser. No.
11/041,767, filed Jan. 24, 2005, the disclosure of which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to heat exchangers,
particularly very high efficiency heat exchangers and heat
exchanger systems.
SUMMARY OF THE INVENTION
[0003] Heat exchangers are used in a great many mechanical and
electrical systems. Some of the most commonly known applications
include the condenser of a refrigerator or the radiator of an
automobile. Increasingly, customers have demanded high efficiency
heat exchangers for cooling computer chips and other electronic
components. This demand, among others, produces a continuing need
for increased efficiency in a smaller volume.
[0004] Compact heat exchangers are used in applications which
demand low overall mass or weight. Until recently, such a heat
exchanger was incapable of transferring the amounts of heat
necessary for certain applications, such as an automobile. It is
desirable to reduce the size of the necessary heat exchanger while
maintaining the rate of heat exchange. Unfortunately, the small
features which allow for high heat transfer create correspondingly
high pressure drops in the working fluids.
[0005] The rate of heat transfer for a given heat exchanger is
related to the surface area-to-volume ratio of the fluid channels.
Advances in microfabrication allow the design of a heat exchanger
to increase the amount of surface area in relation to the overall
volume. As is well understood in the field, the overall heat
transfer of a given fluid channel increases when the hydraulic
diameter of that channel decreases. So-called microchannels provide
the reduction in hydraulic diameter necessary to produce the
required heat transfer performance.
[0006] Typically, the prior art defines a microchannel as any fluid
flow channel with a smallest dimension less than 2.0 mm. See, e.g.,
WO 2004/017008 A1. Microchannels necessarily impose a significant
increase in pressure drop over more conventional flow channels.
[0007] In further illustration, U.S. Patent Application
2002/0125001 A1 discusses, in detail, the history of so-called
micro heat exchangers and highlights the high pressure drops
created in those designs. The heat exchanger disclosed in that
application consists of two sets of microchannels. The length of
the first fluid channels, claimed for the first time, is less than
6.0 mm and preferably less than 1.0 mm. At the same time, that heat
exchanger shows that the first fluid channels number at least 50
per square centimeter, preferably as much as 1000 per square
centimeter.
[0008] These inventions describe and explain the need for thin
panel heat exchangers, defined as a heat exchanger with shortest
fluid channel less than 2.0 cm long.
[0009] The inventions described in existing Patents and patent
applications such as U.S. Patent Application 2002/0125001 A1
demonstrate the utility of thin panels for high heat transfer
performance in a small volume. Even these breakthroughs, however,
are subject to limitations based on allowable pressure drops. In
addition, sometimes a single thin panel heat exchanger cannot
provide the required heat transfer because it does not provide
enough surface area.
[0010] The current invention extends the utility of these thin
panel designs by providing multiple orientations and other options
which serve to increase the effective surface area without
necessarily increasing the frontal area of the heat exchanger
system.
[0011] For instance, a typical thin panel heat exchanger is
oriented so that its shortest flow channels are parallel to the
approaching external fluid flow (the impinging flow). This is
intended to minimize the pressure drop for that external fluid. The
current invention, however, contemplates a thin panel heat
exchanger inclined so that the approaching external fluid flow is
no longer parallel to the fluid channels in the panel. With an
inclined panel, the ratio of surface area to frontal area increases
dramatically.
[0012] Experimentation has proven that a thin panel of the sort
contemplated by the inventions discussed above may be inclined
eighty (80) degrees from perpendicular with no appreciable effect
on pressure drop. If a system is amenable to some pressure drop,
the thin panels may be inclined to eighty five (85) degrees from
perpendicular.
[0013] Experimentation has also proven that inclination of such a
panel does not adversely affect the heat transfer properties of the
panel, assuming the eventual configuration of headers, manifolds or
other components assures proper distribution of fluid through both
the internal and external channels.
[0014] Once it is established that a panel may be inclined, two
panels may be included in a heat exchanger system by making a `v`
shape. In fact, such a v-shape may be repeated many times to create
a system with a great number of panels and still retain the
advantages of a small frontal area.
[0015] A typical thin panel heat exchanger disclosed in the prior
art contemplates the external fluid flow impinging perpendicular to
the face of the panel, as if the panel is mounted in a duct. In
that configuration, the panel may be plumbed so that an internal
fluid passed from one side of the duct to the other. If such a
panel is inclined away from the perpendicular, and especially if
multiple v-shape configurations are included, plumbing the internal
fluid flow requires new solutions.
[0016] The current invention also addresses this concern. Internal
fluid flow may be plumbed through tubes which feed one or more
panels. In addition, a manifold may feed internal fluid flow to all
of the panels at one time. The manifold can be made integrally with
structural members of the total heat exchanger system, providing
for a savings in total weight by removing mass which does not
facilitate heat transfer.
[0017] As an added bonus, once the thin panel cross flow micro heat
exchanger is created, a person having ordinary skill in the art
would be able to design heat exchanger systems which incorporate
multiple panels in various alignments, such as stacking panels. One
example of a heat exchanger system incorporates several thin panels
in a corrugated pattern to increase thermal transfer as a factor of
frontal area. If a single fluid flow passed through multiple
panels, these panels are described as `in series`. If a single
fluid flow may pass through one panel without passing through a
separate panel, these panels are described as `in parallel`.
[0018] These and other embodiments and features of the present
invention will become even more apparent from the following
detailed description of preferred embodiments, the accompanying
figures, and the appended claims. As used in this description, the
term "microchannel" is used to mean a channel with at least one
dimension on the scale of 2.0 mm or less. A "thin panel heat
exchanger" is used to mean a heat exchanger with the shortest fluid
flow channel less than 2.0 cm in length.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a simple embodiment of a thin panel heat
exchanger in accordance with the previously claimed invention.
[0020] FIG. 2 is a picture showing a complete view of a heat
exchanger panel, including tubes which provide the coolant-side
flow to the panel. Fluid 1 flows through the tubes to the internal
channels of the thin panel, while Fluid 2 impinges the panel normal
to the plane of the panel.
[0021] FIG. 3 contains three photographs of a heat exchanger system
employing four thin panel heat exchangers. Each panel is set at an
angle to the impinging flow to increase heat transfer as a function
of frontal area. Coolant flow is delivered to the thin panels via
the tubes extending from the housing. The air flow arrives via a
rectangular duct which matches the housing shown.
[0022] FIG. 4 is a representation of a corrugated multi-panel heat
exchanger, one of the applications of the current invention. It
includes a coolant inlet. The water is then distributed among the
separate panels by the integral manifold. After traveling through
the panels, here arranged in parallel, the coolant is collected by
another manifold and fed into piping or some other outlet path.
[0023] FIG. 5 is a drawing of one of the manifolds used to both
mount and plumb the thin panels in a corrugated arrangement such as
that used in FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A schematic illustration of an embodiment of a thin panel
heat exchanger is shown in FIG. 1 (not drawn to scale). In FIG. 1,
the circular tubes are flow paths for a hot gas. The broad faces of
the thin panel provide one large channel for the liquid flow path.
This liquid flow path is broken up by the multitude of circular
tubes. This arrangement creates a relatively large amount of
primary surface area for heat transfer between the two fluids.
[0025] The flat panel illustrated in FIG. 1 is only an example of a
thin panel heat exchanger. Any heat exchanger which has a shortest
fluid flow channel less than 2.0 cm can be used to take advantage
of the current invention.
[0026] FIG. 2 is a picture of a thin panel heat exchanger made part
of a heat exchanger system which delivers coolant to the panel
through tubes. Each tube has a slot in which the panel may be
mounted. The panel is brazed or otherwise fixedly connected to the
tubes. Fluid 1, typically the coolant, is delivered to the interior
of the panel through the upper tube and removed via the lower
tube.
[0027] This figure does not illustrate the plumbing for the other
fluid flow, but the entire panel may be mounted inside a duct or
other piping to provide cooling for Fluid 2 flowing through that
duct.
[0028] FIG. 3 includes several pictures of a more complex heat
exchanger system. In this system, four large thin panel heat
exchangers are mounted in a v-configuration. This system allows
greater thermal efficiency in a small frontal area than a single
panel would allow. The cooling fluid is fed into the panels by
means of an integral manifold at the top and the bottom of the heat
exchanger assembly. The hot side fluid flows into the heat
exchanger through the open area shown.
[0029] FIG. 4 is a conceptual design using multiple thin panel heat
exchangers in a corrugated arrangement. The dimensions shown are
illustrative only. Persons having ordinary skill in the art will be
able to array thin panel heat exchangers in a variety of
configurations to take advantage of the unique qualities of the
current invention.
[0030] FIG. 5 illustrates a typical manifold used to create a
corrugated arrangement similar to the one depicted in FIG. 4. The
thin panels are mounted in slots (10), which provide structural
support for the core of the heat exchanger assembly. Each slot (10)
has an inlet port (15) which provides fluid flow to the panel. The
ports (15) are all fed by a single inlet (20) made integral with
the manifold. In this manner, multiple panels may be mounted at an
angle to the impinging fluid flow and coolant delivered through a
single fitting.
[0031] In order to increase the total amount of heat transfer
between the working fluids, additional surface area may be added to
the thin panel. This may be done by attaching fins, pins or
expanded metal foam to one or more of the thin panels. Depending on
the material comprising the body of the thin panel, additional
structures may be plated, brazed, welded or otherwise attached. The
most typical application is to attach fins to the downstream face
of the thin panel, that is, away from the impingement of the fluid
streams.
[0032] It is well understood by persons having ordinary skill in
the art that the addition of secondary heat transfer surfaces such
as fins, pins or expanded metal foam will cause additional pressure
drop for the fluid encountering such secondary surfaces. This
effect can be used by one skilled to adjust the flow through a
panel. For instance, it is understood that a thin panel heat
exchanger, when inclined away from perpendicular to the fluid flow,
may see a maldistribution of fluid flow to the downstream portion
of the panel. Secondary surfaces may be selectively mounted to
redirect fluid flow to the upstream portion of the thin panel.
Fabrication of the Heat Exchanger Assembly
[0033] There are many ways to build a complete heat exchanger
system using the current invention. A single thin panel may be
plumbed with tubing to provide the internal flow (coolant flow).
That tubing may be attached by brazing, welding or with an epoxy
adhesive. The thin panel, with its plumbing in place, may be
mounted in a duct or other piping system. That duct would be used
to deliver the external flow to the thin panel heat exchanger. A
potential mounting system is clamping the thin panel with gaskets
to the duct or piping.
[0034] Multiple thin panels may be attached in a similar manner.
Tubes can be used to deliver coolant flow, and the thin panels can
be mounted in a duct, whether perpendicular to the flow through the
duct, or inclined at some angle. Once again, the panels may be
clamped to the duct using a gasket.
[0035] In the preferred embodiment, the thin panels are mounted
first to a housing. This housing, such as that shown in FIG. 4,
includes integral manifolds to both feed and remove the coolant to
the heat exchanger panels. The manifold contains slots for mounting
the thin panels. In each slot, there is a hole which allows fluid
flow from piping or tubes to pass into the internal fluid channels
of the thin panel. A typical manifold is depicted in FIG. 5.
[0036] In the preferred embodiment, the thin panel heat exchangers
are fixedly connected to both the top and bottom manifold. If the
panels are metal, typical brazing, soldering or welding techniques
are appropriate methods of connection.
[0037] Two manifolds make up the top and bottom of the main flow
channel for the hot side flow. An entry manifold receives coolant
flow and feeds it to the thin panels. The exit manifold collects
coolant flow from the thin panels. In addition, sides may be
attached to the manifold panels to complete a main flow channel.
The housing, comprising two manifolds and the side panels, can be
bolted or otherwise mounted to the duct, piping, or other flow path
for the external fluid.
[0038] The preferred embodiment of the manifold is as depicted in
FIG. 5. The thin panel heat exchangers are mounted with open faces
in slots machined in the manifold (10). Each slot (10) has an inlet
port (15) which provides fluid flow to the panel. The ports (15)
are all fed by a single inlet (20) made integral with the manifold.
In this manner, multiple panels may be mounted at an angle to the
impinging fluid flow and coolant delivered through a single
fitting.
[0039] Coolant flow may be delivered to the manifolds in any of a
number of methods known to those having ordinary skill in the art.
Most typical is rigid or flexible tubing from the coolant supply to
the entry manifold and from the exit manifold back to the coolant
supply.
[0040] Once the assembly is complete, it can be placed in the flow
path of the external fluid flow, such as the air duct of a vehicle
or air conditioner. Persons having ordinary skill in the art will
be able to design appropriate interfaces, such as flanges and
gaskets, to properly attach the heat exchanger assembly to such a
duct.
[0041] Each and every patent, patent application and printed
publication referred to above is incorporated herein by reference
in toto to the fullest extent permitted as a matter of law.
[0042] This invention is susceptible to considerable variation in
its practice. The forgoing description, therefore, should not be
construed as limiting the invention to the particular embodiments
presented hereinabove. Rather, what is intended to be covered is as
set forth in the ensuing claims and the equivalents thereof
permitted as a matter of law.
* * * * *