U.S. patent application number 12/843200 was filed with the patent office on 2011-02-17 for integral evaporator and defrost heater system.
Invention is credited to Brian John Christen, Scot Reagen, David Wayne Skrzypchak, William Sprow.
Application Number | 20110036553 12/843200 |
Document ID | / |
Family ID | 43586739 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110036553 |
Kind Code |
A1 |
Christen; Brian John ; et
al. |
February 17, 2011 |
INTEGRAL EVAPORATOR AND DEFROST HEATER SYSTEM
Abstract
A heat exchanger system having a fluid passage operable to
fluidly communicate a first fluid and a heat transfer surface
extending from the fluid passage for transferring heat between the
first fluid and a second fluid. The system can further include a
heating element operably coupled to and selectively applying
thermal energy to at least one of the fluid passage and the heat
transfer surface.
Inventors: |
Christen; Brian John;
(Monroe, MI) ; Reagen; Scot; (Sylvania, OH)
; Skrzypchak; David Wayne; (Adrian, MI) ; Sprow;
William; (Adrian, MI) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
43586739 |
Appl. No.: |
12/843200 |
Filed: |
July 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61233156 |
Aug 12, 2009 |
|
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|
Current U.S.
Class: |
165/185 |
Current CPC
Class: |
F28F 19/006 20130101;
F28D 1/0477 20130101; F28F 1/16 20130101; F28F 1/26 20130101; F28F
2255/16 20130101 |
Class at
Publication: |
165/185 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Claims
1. A heat exchanger system comprising: a fluid passage operable to
fluidly communicate a first fluid; a heat transfer surface
extending from said fluid passage for transferring heat between
said first fluid and a second fluid; and a heating element operably
coupled to and selectively applying thermal energy to at least one
of said fluid passage and said heat transfer surface.
2. The heat exchanger system according to claim 1 wherein said
fluid passage and said heat transfer surface are formed from a
single sheet of material, said single sheet of material having
opposing ends and being formed to define said fluid passage, said
heat transfer surface, and a sealed area whereby said opposing ends
are joined.
3. The heat exchanger system according to claim 2 wherein said
sealed area is welded by laser, ultrasonics, or electric arc, or
brazed.
4. The heat exchanger system according to claim 2, wherein said
heating element is sheathed using said single sheet of
material.
5. The heat exchanger system according to claim 1 wherein said
fluid passage and said heat transfer surface are a unitarily-formed
extrusion.
6. The heat exchanger system according to claim 5 wherein said
heating element is encapsulated within said unitarily-formed
extrusion.
7. The heat exchanger system according to claim 1, further
comprising: a heater element passage formed with at least one of
said fluid passage and said heat transfer surface, said heater
element passage being sized to permit subsequent insertion of said
heating element therein.
8. The heat exchanger system according to claim 7 wherein said
heating element passage is fluidly separate from said fluid
passage.
9. The heat exchanger system according to claim 1 wherein said
heating element is mechanically coupled to at least one of said
fluid passage and said heat transfer surface.
10. The heat exchanger system according to claim 1 wherein said
heating element comprises varying thermal energy output along its
length for localized heating.
11. The heat exchanger system according to claim 1 wherein said
heat transfer surface comprises a wave-like shape.
12. The heat exchanger system according to claim 1 wherein said
heat transfer surface comprises a plurality of spines.
13. The heat exchanger system according to claim 1 wherein said
heat transfer surface is angled in a direction of flow of said
second fluid.
14. The heat exchanger system according to claim 1 wherein said
fluid passage comprises a round cross-sectional shape.
15. The heat exchanger system according to claim 1 wherein said
fluid passage comprises an oval cross-sectional shape.
16. The heat exchanger system according to claim 1 wherein said
fluid passage comprises an airfoil cross-sectional shape.
17. The heat exchanger system according to claim 1 wherein at least
one of said fluid passage and said heat transfer surface is made of
aluminum.
18. The heat exchanger system according to claim 1 wherein said
fluid passage and said heat transfer surface are each made of
different material.
19. The heat exchanger system according to claim 1 wherein said
fluid passage, said heat transfer surface, and said heating element
collectively form an arcuate shape along at least a portion
thereof.
20. A heat exchanger system comprising: a first passage operable to
fluidly communicate a first fluid; a first heat transfer surface
extending from said first passage for transferring heat between
said first fluid and a second fluid; a first heating element
operably coupled to and selectively applying thermal energy to at
least one of said first passage and said first heat transfer
surface; a second passage operable to fluidly communicate said
first fluid; a second heat transfer surface extending from said
second passage for transferring heat between said first fluid and a
second fluid; and a connecting passage fluidly coupling said first
passage and said second passage for communication of said first
fluid.
21. The heat exchanger system according to claim 20 wherein at
least said first passage and said second passage together forming
an arcuate shape along at least a portion thereof.
22. The heat exchanger system according to claim 20 wherein at
least said first passage and said first heat transfer surface are a
unitarily-formed extrusion.
23. The heat exchanger system according to claim 20, further
comprising: a second heating element operably coupled to at least
one of said second passage and said second heat transfer
surface.
24. The heat exchanger system according to claim 20 wherein said
first passage and said first heat transfer surface are formed from
a single sheet of material, said single sheet of material having
opposing ends and being formed to define said first passage, said
first heat transfer surface, and a sealed area whereby said
opposing ends are joined.
25. The heat exchanger system according to claim 20 wherein said
connecting passage fluidly couples said first passage and said
second passage in parallel.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/233,156, filed on Aug. 12, 2009. The entire
disclosure of the above application is incorporated herein by
reference.
FIELD
[0002] The present disclosure relates to heat exchangers and, more
particularly, to an integrally formed evaporator having a defrost
heater system.
BACKGROUND AND SUMMARY
[0003] This section provides background information related to the
present disclosure which is not necessarily prior art. This section
also provides a general summary of the disclosure, and is not a
comprehensive disclosure of its full scope or all of its
features.
[0004] Heat exchangers are used in a wide variety of applications
and come in a wide variety of configurations to fit these various
applications. A typical heat exchanger uses a fluid transporting
unit or tube portion operable to transport a fluid therethrough,
such as heat conducting tubing arranged in a sinuous configuration,
and a plurality of heat conducting fins (fin bank) in heat
conducting contact with the tube portion. One fluid flows through
the tube portion and another fluid flows along the outer surface of
the tube portion between the fins thereon to transfer heat between
the two fluids. Typically the tube portion is arranged in a sinuous
configuration with substantially straight segments being
interconnected by connecting segments (typically semicircular
segments) so that the fluid flowing within the tube portion passes
through the fin bank a desired number of times. Due to the
differing applications that the heat exchangers are used in, the
heat exchangers will come in a variety of shapes that require fins
having differing quantities of columns of openings that the
straight segments pass through.
[0005] The fins are typically stamped from a sheet of heat
conducting material with a die configured to produce a plurality of
columns of openings in the sheet for each stamp of the die (i.e.,
2, 3, 4, etc. columns per stamp). The number of rows of openings in
each column is determined by the height of the sheet of heat
conducting material from which the fins are stamped (i.e., the
sheet can have a height that yields 2, 3, 4, etc. rows of openings
per stamp of the die).
[0006] Tube and fin evaporators, being a type of heat exchanger,
have been used for decades in a wide variety of applications. These
devices have been optimized to a point where little can be gained
without a major leap in technology.
[0007] For example, in refrigeration and freezer applications, an
evaporator is often installed with a defrost heater. The defrost
heater must be sheathed to protect it from moisture and attached to
the evaporator. The sheathing and attachment method often result in
added cost that adds no additional value to the final product.
Therefore, it has been found that by making the evaporator and
heater an integral piece can greatly reduce the overall cost of
manufacturing the product. With current technology, complex shapes
must often be avoided as they tend to collect frost and are
correspondingly difficult to defrost.
[0008] Therefore, according to the principles of the present
teachings, a heat exchanger system is provided that comprises a
fluid passage operable to fluidly communicate a first fluid and a
heat transfer surface extending from the fluid passage for
transferring heat between the first fluid (i.e. refrigerant) and a
second fluid (i.e. air). In some embodiments, the heat exchanger
system can comprise a heating element operably coupled to the fluid
passage and/or the heat transfer surface to provide, in some cases,
a defrost function. At least the fluid passage and the heat
transfer surface can be a unitarily-formed extrusion.
[0009] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0010] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0011] FIG. 1 is a perspective view of a heat exchanger system
having a plurality of spines according to some embodiments of the
present teachings;
[0012] FIG. 2 is a perspective view of a heat exchanger system
according to some embodiments of the present teachings;
[0013] FIG. 3 is a perspective view of a heat exchanger system
having a heating system according to some embodiments of the
present teachings;
[0014] FIG. 4 is a perspective view of the heat exchanger system
having a heating system and a plurality of spines according to some
embodiments of the present teachings;
[0015] FIG. 5 is a perspective view of a heat exchanger
(evaporator) incorporating the principles of the present teachings;
and
[0016] FIG. 6 is a schematic cross-sectional view of the heat
exchanger system having a heating system.
[0017] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0018] Example embodiments will now be described more fully with
reference to the accompanying drawings. Example embodiments are
provided so that this disclosure will be thorough, and will fully
convey the scope to those who are skilled in the art. Numerous
specific details are set forth such as examples of specific
components, devices, and methods, to provide a thorough
understanding of embodiments of the present disclosure. It will be
apparent to those skilled in the art that specific details need not
be employed, that example embodiments may be embodied in many
different forms and that neither should be construed to limit the
scope of the disclosure.
[0019] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a", "an" and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0020] When an element or layer is referred to as being "on",
"engaged to", "connected to" or "coupled to" another element or
layer, it may be directly on, engaged, connected or coupled to the
other element or layer, or intervening elements or layers may be
present. In contrast, when an element is referred to as being
"directly on," "directly engaged to", "directly connected to" or
"directly coupled to" another element or layer, there may be no
intervening elements or layers present. Other words used to
describe the relationship between elements should be interpreted in
a like fashion (e.g., "between" versus "directly between,"
"adjacent" versus "directly adjacent," etc.). As used herein, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0021] Referring to FIGS. 1 and 2, according to some embodiments of
of the present teachings, a heat exchanger system 20 is provided
having a fluid a fluid passage 22 extending therethrough configured
and adapted to fluidly carry coolant refrigerant or other fluid
therein. Heat exchanger system 20 can further comprise an
integrally-formed heat transfer surface 32 extending from fluid
passage 22. Heat transfer surface 32 being configured and adapted
to transfer thermal energy between the coolant refrigerant within
fluid passage 22 and a fluid, such as air, external to heat
exchanger system 20 adjacent heat transfer surface 32, as will be
described in greater detail.
[0022] In some embodiments, heat exchanger system 20 can comprise a
thin sheet of material. This thin sheet can be made from any one of
a number of materials or alloys, such as aluminum, that have
desired conductivity properties. This thin sheet material can be
roll formed to achieve uniformity and desired material
properties.
[0023] In some embodiments, heat exchanger system 20 can be
extruded as a single unitary member defining at least fluid passage
22 and heat transfer surface 32. The extrusion can be made from any
one of a number of materials or alloys, such as aluminum, that have
desired conductivity and extrusion properties. It should be
recognized that extruding heat exchanger system 20 provides several
advantages over conventional manufacturing techniques, such as
improved heat transfer capability per material weight, reduced
manufacturing costs by simultaneously forming the fluid passage 22
and heat transfer surface 32, reduced material requirements due to
the improved mechanical properties of extrusions, and simplified
cross-sectional shaping of the overall structure for improved fluid
flow within fluid passage 22 and external to heat exchanger system
20.
[0024] In some embodiments, heat exchanger system 20 can be
contoured or otherwise shaped to any desired configuration. In some
embodiments, this desired configuration generally comprises a
hollow fluid passage 22 sized to carry liquid refrigerant
therethrough to facilitate thermodynamic heat transfer. In some
embodiments using a thin sheet material, heat exchanger system 20
can be shaped such that an end 26 of the sheet is adjacent to a
mid-section 28 of the sheet. This relative proximal relationship of
end 26 to mid-section 28 can extend over a sealed and/or
overlapping region 30. The sealed region 30 can be sealed to form a
fluid tight connection via conventional welding, laser welding,
ultrasonic welding, electric arc welding, or other means, such as
brazing, bonding, or otherwise joining. It should be appreciated
that sealed or overlapping region 30 can comprise any one of a
number of sealing joints, such as a lap joint, butt joint, weld
joint, or, in some embodiments as discussed herein, being unitarily
extruded. In some embodiments, sealed region 30 can comprise a
narrow layer of silicon rich alloy coated on the sheet to
facilitate brazing. It should be recognized that a similar profile
can be used in connection with embodiments formed through extrusion
with the obvious elimination of the need to seal mid-section 28. It
should be appreciated that in some embodiments a separate fluid
passage member, such as a tubular member (i.e. perhaps made of
plastic or other material), can be used as fluid passage 22 and the
thin sheet material can be wrapped or otherwise formed about the
tubular member to minimize the complexity of ensuring fluid sealing
of fluid passage 22.
[0025] As described above, heat exchanger system 20 can further
comprise heat transfer surface 32. In some embodiments, heat
transfer surface 32 can extend from mid-section 28 to form a heat
transfer section particularly suited to enhanced heat transfer from
the liquid refrigerant to a fluid external to heat exchanger system
20, such as ambient air. The fluid passage 22 can be shaped or
extruded to include any one of a number of shapes, such as round,
oval, airfoil, and the like. Moreover, the heat exchanger system 20
can be bent or extruded in a serpentine pattern to form an
evaporator to fit within the allowable envelope or the
refrigeration or air conditioning device (see FIG. 5). It should be
appreciated that heat exchanger system 20 can be formed as a
straight, arcuate, or other unique shape or pattern, such as
spiral, sinusoidal, curved, conical, or the like.
[0026] In some embodiments, the heat transfer surface 32 can be cut
or otherwise shaped to include a plurality of spines 34 that
enhance heat transfer. Similarly, in some embodiments, the heat
transfer surface 32 can be angled in the direction of airflow to
improve heat transfer.
[0027] Heat transfer can be considered paramount in such
applications and as such refrigerant passage 22 can similarly be
shaped to enhance heat transfers, such as defining a round, oval,
or airfoil shape.
[0028] With particular reference to FIGS. 3 and 4, heat exchanger
system 20 can further comprise a heating element 40 coupled to the
thin sheet or coextruded with fluid passage 22 and heat transfer
surface 32. That is, in the thin sheet embodiments, heating element
40 can be sheathed in intimate contact with the thin sheet.
Moreover, heating element 40 can be contained or otherwise
sandwiched at or near sealed region 30 to protect heating element
40 from damage and further provide improved heat transfer during
defrost cycles. Heating element 40 can be coupled or captured to
thin sheet 22 during the forming process to simplify manufacturing
thereof. In some embodiments, a heater element passage 42 can be
formed during shaping of thin sheet 22 and heating element 40 can
be inserted therein. The thin sheet 22 acts as the sheath for the
heating element 40.
[0029] However, in the extrusion embodiment, heating element 40 can
be disposed within a heating element passage 42 formed in heat
exchanger system 20. Heating element passage 42 can be coextruded
during the formation of fluid passage 22 and heat transfer surface
32 so as to form a unitary extrusion having fluid passage 22, heat
transfer surface 32, and heating element passage 42. In some
embodiments, heating element passage 42 is extruded around heating
element 40, thereby encapsulating heating element 40. In some
embodiments, heating element passage 42 is extruded for later
insertion of heating element 40.
[0030] It should be appreciated that by incorporating heating
element 40 into the structure of heat exchanger system 20,
particularly adjacent and integral with fluid passage 22 and heat
transfer surface 32, heating element 40 can more rapidly defrost
the heat exchanger system, thereby allowing more complex, higher
performing geometries to be used. Moreover, it should be
appreciated that heating element 40 of the present teachings
further provides improved defrosting efficiency due to its proximal
positioning relative to fluid passage 22 and/or heat transfer
surface 32. This proximal positioning is maximized by the unique
structure of the present teachings.
[0031] Therefore, according to the principles of the present
teachings, a heat exchanger system is provided that comprises a
fluid passage operable to fluidly communicate a first fluid and a
heat transfer surface extending from the fluid passage for
transferring heat between the first fluid and a second fluid. The
heat exchanger system can further comprise a heating element that
is operably coupled to and capable of selectively applying thermal
energy to at least one of the fluid passage and the heat transfer
surface. The heating element can be sheathed or otherwise covered
or encapsulated to protect the heating element.
[0032] In some embodiments, the heat exchanger system can be
configured such that the fluid passage and the heat transfer
surface are formed from a single sheet of material. The single
sheet of material can have opposing ends and can be shaped to
define the fluid passage, the heat transfer surface, and a sealed
area between the fluid passage and the heat transfer surface where
the opposing ends are joined. These ends can be welded by laser,
ultrasonics, electric arc or other means. In some embodiments, a
layer of silicon rich alloy can be disposed at the overlapping area
to facilitate brazing.
[0033] In some embodiments, the heat exchanger system can be
configured such that the fluid passage and the heat transfer
surface are a unitarily-formed extrusion. If desired, the heating
element can be encapsulated within the unitarily-formed
extrusion.
[0034] However, in some embodiments, a heater element passage can
be formed with at least one of the fluid passage and the heat
transfer surface. The heater element passage can be sized to permit
subsequent insertion of the heating element therein. The heating
element passage can be fluidly separate from the fluid passage.
Although, in some embodiments, the heating element can be
mechanically coupled to at least one of the fluid passage and the
heat transfer surface. The heating element can be operated such
that its thermal energy output is varied along its length for
localized heating.
[0035] In some embodiments, the heat transfer surface can define a
wave-like shape and/or a plurality of spines. The heat transfer
surface can be angled in a direction of flow of the second fluid
for improved heat transfer.
[0036] In some embodiments, the fluid passage can define a round
cross-sectional shape, an oval cross-sectional shape, an airfoil
cross-sectional shape, or other desired configuration.
[0037] It should be appreciated that at least one of the fluid
passage and the heat transfer surface can be made of aluminum,
and/or can be made of different materials.
[0038] In some embodiments, the aforementioned structure can be
combined with similar structure as a multi-passage heat exchanger
system and/or can define an arcuate shape. It should be appreciated
that the heat exchanger system can be formed as a straight,
arcuate, or other unique shape or pattern, such as spiral,
serpentine, sinusoidal, curved, conical, or the like. Moreover, in
some embodiments, a plurality of passages can be operably coupled
to define a multi-passage heat exchanger system. The plurality of
passages as described herein can be joined via connecting
passage(s), jumper tube(s) and/or can comprise headers in parallel
or series to form a single refrigerant carrying device. In some
embodiment, only a single heating element can be used for the
multi-passage heat exchanger system.
[0039] Finally, it should be appreciated that the aforementioned
first fluid can comprise a refrigerant and the second fluid can
comprise air.
[0040] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the invention, and all such modifications are intended to be
included within the scope of the invention.
* * * * *