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|United States Patent Application
Herrera; Carlos A.
;   et al.
March 15, 2012
HEAT EXCHANGER FOR AN APPLIANCE
An improved heat exchanger for an appliance is provided. More
particularly, the present invention provides a new condenser for a
refrigerator that is formed from a conduit wound into the shape of a
conical helix. Extensions from the surface of the conduit provide
additional area for heat exchange. A fan can be aligned with the conical
helix to further improve heat transfer.
Herrera; Carlos A.; (Fisherville, KY)
; Beers; David Gardner; (Elizabeth, IN)
; Shaver; Scott Alan; (Louisville, KY)
; Hitzelberger; Joel Erik; (Louisville, KY)
; Junge; Brent Alden; (Evansville, IN)
; Kempiak; Michael John; (Osceola, IN)
GENERAL ELECTRIC COMPANY
October 21, 2010|
|Class at Publication:
||F25B 39/04 20060101 F25B039/04|
1. A refrigerator having a gas cooling device, comprising: a refrigerant
system including a condenser portion for cooling a refrigerant, said
condenser portion comprising: a thermally-conductive conduit wound in the
shape of a conical helix, the conical helix defining a spiral axis; and a
plurality of radial spine fins projecting from the surface of said
2. A refrigerator having a gas cooling device as in claim 1, further
comprising a fan to create an air flow over said thermally-conductive
3. A refrigerator having a gas cooling device as in claim 2, wherein said
the direction of the air flow is parallel to the spiral axis defined by
the conical helix of said thermally-conductive conduit.
4. A refrigerator having a gas cooling device as in claim 3, wherein the
conical helix of said thermally-conductive conduit tapers in the
direction opposite of the air flow.
5. A refrigerator having a gas cooling device as in claim 1, wherein said
thermally-conductive conduit comprises a copper tube.
6. A refrigerator having a gas cooling device as in claim 1, wherein said
refrigerator further comprises a compartment for receipt of said
thermally-conductive conduit, said compartment configured for directing
the flow air over said thermally-conductive conduit.
7. A refrigerator having a gas cooling device as in claim 1, wherein said
thermally-conductive conduit defines an air-flow passage within the
conical helix, the air-flow passage being unobstructed such that air may
flow freely through.
8. A refrigerator having a gas cooling device as in claim 1, further
comprising a fan positioned at an end of the conical helix of said
thermally-conductive conduit having the largest radius.
9. A gas cooling device for use in a refrigerator, the device comprising:
a conduit for carrying refrigerant, said conduit formed into the shape of
a conical helix having an axis about which the conical helix is coiled,
said conduit having a surface; and pin-like elements projecting from the
surface of the conduit; wherein said conduit and said pin-like elements
are constructed from one or more thermally-conductive materials.
10. A gas cooling device as in claim 9, further comprising a fan
positioned at one end of said conduit to create a flow of air over said
conduit and said pin-like elements.
11. A gas cooling device as in claim 10, wherein the flow of air is along
a direction perpendicular to the axis of said conduit.
12. A gas cooling device as in claim 10, wherein said fan is positioned
at the end of said conduit that has the largest radius from the axis of
the conical helix.
13. A gas cooling device as in claim 10, wherein the conical helix of
said conduit tapers in a direction opposite to the direction of the flow
14. A gas cooling device as in claim 9, wherein said conduit comprises
15. A gas cooling device as in claim 9, where said conduit is installed
within a condenser portion of a refrigerant loop on a refrigerator.
16. A gas cooling device as in claim 9, wherein said conduit defines an
air-flow passage within the conical helix, the air-flow passage being
unobstructed such that air may flow over and through the conduit.
FIELD OF THE INVENTION
 The present invention relates to an improved heat exchanger for an
appliance. More particularly, the present invention relates to a new
condenser for a refrigerator that is formed in the shape of a conical
BACKGROUND OF THE INVENTION
 Modern refrigerator appliances use a gas-based refrigerant to
provide cooling for the fresh food and/or freezer compartment of the
refrigerator. The refrigerant is circulated within a loop that includes
passage through the inside compartment(s) of the refrigerator. Heat is
withdrawn from inside the refrigerator by changing state from a liquid to
a gas. Thereafter, the refrigerant is compressed and subsequently cooled
by passage through a heat exchanger--more commonly referred to as a
condenser. The condenser is typically exposed to ambient air for heat
 The condenser's exchange of heat with ambient air requires that the
condenser have enough surface area to adequately dissipate the heat
created by compression. Typically, this surface area is provided, for
example, by configuring the condenser as metal tubing positioned on the
bottom or the rear of the refrigerator. Compressed refrigerant is
circulated through the metal tubing. As ambient air comes into contact
with the metal tubing, heat is exchanged and the refrigerant is cooled.
Natural convection created by movement of the heated air across the
surface of the metal tubing can facilitate the exchange of heat by
carrying heated air away from the condenser, which will be replaced by
 There are certain challenges to the use of this conventional
approach. For example, the addition of metal tubing onto the rear of the
refrigerator increases the depth required for placement of the
refrigerator within, for example, a kitchen area. For compact
applications, such as under-the-counter installations, space is limited
such that it may be difficult to use enough tubing or provide sufficient
ventilation to achieve the necessary amount of heat exchange. Increasing
the length of the tubing used for the condenser can increase the heat
exchange capacity of the refrigerator but at the expense of increased
materials costs for manufacture. The use of natural convection for the
movement of air across the condenser can be inefficient for certain
applications. Finally, the tubing of the condenser will frequently
collect dust that is infrequently (if at all) removed by cleaning. Such
dust will eventually decrease the heat exchange capability of the
condenser as it builds up on the tubing.
 Accordingly, an improved heat exchanger for cooling of the
compressed gas portion of a refrigeration loop (i.e. condenser) is
needed. More particularly, a heat exchanger that can provide improved
efficiency in cooling the compressed gas would be useful. Such a heat
exchanger for a refrigerator condenser that can be efficiently used in
compact appliance designs would also be beneficial. Additionally, a heat
exchanger that can also tolerate dust would provide additional
BRIEF DESCRIPTION OF THE INVENTION
 Aspects and advantages of the invention will be set forth in part
in the following description, or may be obvious from the description, or
may be learned through practice of the invention.
 In one exemplary embodiment of the invention, a refrigerator having
a gas cooling device is provided. The refrigerator includes a refrigerant
system having a condenser portion for cooling a refrigerant. The
condenser portion is constructed from a thermally-conductive conduit
wound in the shape of a conical helix. The conical helix defines a spiral
axis. A plurality of radial spine fins project from the surface of the
thermally-conductive conduit to provide additional surface area for heat
 In another exemplary embodiment, the present invention provides a
gas cooling device for use in a refrigerator. The gas cooling device
includes a conduit for carrying refrigerant. The conduit is formed into
the shape of a conical helix having an axis about which the conical helix
is coiled. The conduit has a surface with pin-like elements projecting
from the surface. The conduit and the pin-like elements are constructed
from one or more thermally-conductive materials.
 These and other features, aspects and advantages of the present
invention will become better understood with reference to the following
description and appended claims. The accompanying drawings, which are
incorporated in and constitute a part of this specification, illustrate
embodiments of the invention and, together with the description, serve to
explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
 A full and enabling disclosure of the present invention, including
the best mode thereof, directed to one of ordinary skill in the art, is
set forth in the specification, which makes reference to the appended
figures, in which:
 FIG. 1 provides a front view of a refrigerator, with doors to the
fresh food and freezer compartment opened, according to an exemplary
embodiment of the present invention.
 FIG. 2 provides a schematic of a refrigeration loop having an
exemplary embodiment of a heat exchanger according to the present
 FIG. 3 illustrates a perspective view of an exemplary embodiment of
a heat exchanger of the present invention.
 FIG. 4 provides a top view of the exemplary embodiment of FIG. 3.
 FIG. 5 provides a perspective, end view of an exemplary embodiment
of a heat exchanger of the present invention including a conduit covered
with radial spine fins.
DETAILED DESCRIPTION OF THE INVENTION
 The present invention relates to an improved heat exchanger for an
appliance. More particularly, the present invention relates to a new
condenser for a refrigerator that is formed from conduit wound into the
shape of a conical helix. Extensions from the surface of the conduit
provide additional area for heat exchange. Reference now will be made in
detail to embodiments of the invention, one or more examples of which are
illustrated in the drawings. Each example is provided by way of
explanation of the invention, not limitation of the invention. In fact,
it will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention without
departing from the scope or spirit of the invention. For instance,
features illustrated or described as part of one embodiment can be used
with another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and their
 FIG. 1 provides a front view of a representative refrigerator 10
incorporating an exemplary embodiment of a heat exchanger 66 of the
present invention. For illustrative purposes, the present invention is
described with a refrigerator 10 having a construction as shown and
described further below. As used herein, a refrigerator includes
appliances such as a freezer, refrigerator/freezer combination, compact,
and any other style or model of a refrigerator. Accordingly, other
configurations including multiple and different styled compartments could
be used with refrigerator 10, it being understood that the configuration
shown in FIG. 1 is by way of example only.
 Refrigerator 10 includes a fresh food storage compartment 12 and a
freezer storage compartment 14. Freezer compartment 14 and fresh food
compartment 12 are arranged side-by-side within an outer case 16 and
defined by inner liners 18 and 20 therein. A space between case 16 and
liners 18 and 20, and between liners 18 and 20, is filled with
foamed-in-place insulation. Outer case 16 normally is formed by folding a
sheet of a suitable material, such as pre-painted steel, into an inverted
U-shape to form top and side walls of case 16. A bottom wall of case 16
normally is formed separately and attached to the case side walls and to
a bottom frame that provides support for refrigerator 10. Inner liners 18
and 20 are molded from a suitable plastic material to form freezer
compartment 14 and fresh food compartment 12, respectively.
Alternatively, liners 18, 20 may be formed by bending and welding a sheet
of a suitable metal, such as steel. The illustrative embodiment includes
two separate liners 18, 20 as it is a relatively large capacity unit and
separate liners add strength and are easier to maintain within
manufacturing tolerances. In smaller refrigerators, a single liner is
formed and a mullion spans between opposite sides of the liner to divide
it into a freezer compartment and a fresh food compartment.
 A breaker strip 22 extends between a case front flange and outer
front edges of liners 18, 20. Breaker strip 22 is formed from a suitable
resilient material, such as an extruded acrylo-butadiene-styrene based
material (commonly referred to as ABS). The insulation in the space
between liners 18, 20 is covered by another strip of suitable resilient
material, which also commonly is referred to as a mullion 24. In one
embodiment, mullion 24 is formed of an extruded ABS material. Breaker
strip 22 and mullion 24 form a front face, and extend completely around
inner peripheral edges of case 16 and vertically between liners 18, 20.
Mullion 24, insulation between compartments, and a spaced wall of liners
separating compartments, sometimes are collectively referred to herein as
a center mullion wall 26. In addition, refrigerator 10 includes shelves
28 and slide-out storage drawers 30, sometimes referred to as storage
pans, which normally are provided in fresh food compartment 12 to support
items being stored therein.
 Refrigerator 10 is controlled by a microprocessor (not shown)
according to user preference via manipulation of a control interface 32
mounted in an upper region of fresh food storage compartment 12 and
coupled to the microprocessor. A shelf 34 and wire baskets 36 are also
provided in freezer compartment 14. In addition, an ice maker 38 may be
provided in freezer compartment 14.
 A freezer door 42 and a fresh food door 44 close access openings to
fresh food and freezer compartments 12, 14, respectively. Each door 42,
44 is mounted to rotate about its outer vertical edge between an open
position, as shown in FIG. 1, and a closed position (not shown) closing
the associated storage compartment. Freezer door 42 includes a plurality
of storage shelves 46, and fresh food door 44 includes a plurality of
storage shelves 48.
 FIG. 2 is an elevational schematic view of refrigerator 10 (shown
in FIG. 1) including an exemplary sealed cooling system 60. In accordance
with known refrigerators, refrigerator 10 includes a machinery
compartment 62 that at least partially contains components for executing
a known vapor compression cycle for cooling air. The components include a
compressor 64, a heat exchanger or condenser 66, an expansion valve 68,
and an evaporator 70 connected in series and charged with a refrigerant.
Evaporator 70 is also a type of heat exchanger which transfers heat from
air passing over the evaporator to a refrigerant flowing through
evaporator 70 thereby causing the refrigerant to vaporize. As such,
cooled air is produced and configured to refrigerate compartments 12, 14
of refrigerator 10.
 From evaporator 70, vaporized refrigerant flows to compressor 64,
which operates to increase the pressure of the refrigerant. This
compression of the refrigerant raises its temperature, which is lowered
by passing the gaseous refrigerant through condenser 66 where heat
exchange with ambient air takes place so as to cool the refrigerant. A
fan 72 is used to pull air across condenser 66, as illustrated by arrows
A, so as to provide forced convection for a more rapid and efficient heat
exchange between the refrigerant and the ambient air.
 Expansion valve 68 further reduces the pressure of refrigerant
leaving condenser 66 before being fed as a liquid to evaporator 70.
Collectively, the vapor compression cycle components in a refrigeration
circuit, associated fans, and associated compartments are sometimes
referred to as a sealed refrigeration system operable to force cold air
through refrigeration compartments 12, 14. The refrigeration system
depicted in FIG. 2 is provided by way of example only. It is within the
scope of the present invention for other configurations of the
refrigeration system to be used as well.
 Referring now to FIG. 3, a close-up of an exemplary embodiment of
the heat exchanger or condenser 66 is provided. As shown, condenser 66 is
constructed from a thermally-conductive conduit 74 wound into the shape
of a conical helix having axis T-T. A conical (a/k/a conic) helix can be
described as a spiral wrapped over a conical surface. Each loop 76 of the
conical helix of conduit 74 is at a radius R. Preferably, the radius R of
each successive loop 76 increases along axis T-T in the direction of air
flow shown by arrows A. Stated differently, the conical helix of
condenser 66 tapers in a direction opposite to that of the air flow
induced by fan 72. However, it should be understood that the opposite
direction for air flow A may also be used as well.
 In addition, for the exemplary embodiment of FIG. 3, fan 72 is
located at an end 78 of conduit 74 having the largest radius R for loops
76. The blades of fan 72 are configured to pull air across the conduit 74
of condenser 66. As shown in FIG. 4, the interior 80 of conduit 74
remains unobstructed so that air may flow freely within the interior 80
of conduit 74 as well.
 The use of a conical helix as shown for the construction of conduit
74 increases the heat transfer capability of condenser 66. It is believed
that this configuration improves contact between condenser 66 and air
flowing across it. More specifically, the use of fan 72 further increases
the heat transfer efficiency by providing for a more rapid supply of
non-heated air to condenser 66 and by increasing the overall heat
transfer coefficient therebetween by increasing the velocity of the air
flow above that which would occur solely by natural convection if fan 72
were not used. Additionally, the conical helix improves the flow of air
across all portions of conduit 74, thereby reducing the tendency for a
build-up of dust on condenser 66 that would otherwise reduce its heat
 To further improve the flow of air for heat exchange, condenser 66
may be positioned within a compartment created by walls 82 positioned
about condenser 66 and fan 72. Walls 82 assist fan 72 in providing for a
flow of air across condenser 66 to further improve heat transfer. Walls
82 can be, for example, positioned within machinery compartment 62 to
help direct the flow of unheated air from outside the refrigerator 10 and
across condenser 66. Furthermore, by using fan 72 and/or walls 82, the
velocity of air across condenser 66 can be increased which aids in
reducing the build-up of dust that can reduce the heat exchange
capability of condenser 66.
 As shown more particularly in FIG. 5, the surface of conduit 74 is
covered with multiple, pin-like elements or fins 84 that project out
radially from conduit 74. Radial spine fins 84 increase the area
available for heat transfer with the air. As heated refrigerant flows
through conduit 74, heat energy is conducted from the refrigerant and
into radial spine fins 84 where additional surface area is provided for
heat exchange with air passing across condenser 66. As such, radial spine
fins 84 further increase the heat transfer capability of condenser 66.
 Preferably condenser 66 and radial spine fins 84 are constructed
from a thermally-conductive material such as one or more metals. For
example, condenser 66 may be readily constructed from copper that can be
wound into the conic helix as discussed above. However, other conductive
materials may be used as well.
 This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in the art
to practice the invention, including making and using any devices or
systems and performing any incorporated methods. The patentable scope of
the invention is defined by the claims, and may include other examples
that occur to those skilled in the art. Such other examples are intended
to be within the scope of the claims if they include structural elements
that do not differ from the literal language of the claims, or if they
include equivalent structural elements with insubstantial differences
from the literal languages of the claims.
* * * * *