U.S. patent application number 12/877131 was filed with the patent office on 2010-12-30 for control sytem for bottom freezer refrigerator with ice maker in upper door.
Invention is credited to Russell J. FALLON, Brent Alden JUNGE, Robert Thomas MILLS, Eric PAEZ, Ratnakar SAHASRADBUDHE, Martin Christopher SEVERANCE, Joseph Thomas WAUGH, Kristin Marie WEIRICH.
Application Number | 20100326096 12/877131 |
Document ID | / |
Family ID | 43379257 |
Filed Date | 2010-12-30 |
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United States Patent
Application |
20100326096 |
Kind Code |
A1 |
JUNGE; Brent Alden ; et
al. |
December 30, 2010 |
CONTROL SYTEM FOR BOTTOM FREEZER REFRIGERATOR WITH ICE MAKER IN
UPPER DOOR
Abstract
A refrigerator includes a main body defining a compartment, the
compartment having an access opening and a first wall, a door
supported by the main body for selectively closing at least part of
the access opening, a sub-compartment on the door, the
sub-compartment including a second wall having an opening, a heat
exchanger supported by the first wall and positioned so that when
the door is closed the heat exchanger is exposed to an interior of
the sub-compartment through the opening. The heat exchanger
includes a heat exchanging plate. A sealed refrigeration system
contains a working medium for cooling the heat exchanger and has
one or more segments attached to the heat exchanging plate. A fan
is configured to force air over the heat exchanging plate and into
the interior of the sub-compartment. A thermistor is coupled to the
heat exchanging plate for monitoring a temperature of the heat
exchanging plate. A controller is configured to adjust a speed of
the fan in dependence of the temperature of the heat-exchanging
plate detected by the thermistor.
Inventors: |
JUNGE; Brent Alden;
(Evansville, IN) ; SEVERANCE; Martin Christopher;
(Louisville, KY) ; FALLON; Russell J.;
(Louisville, KY) ; PAEZ; Eric; (Louisville,
KY) ; MILLS; Robert Thomas; (Louisville, KY) ;
SAHASRADBUDHE; Ratnakar; (Louisville, KY) ; WAUGH;
Joseph Thomas; (Louisville, KY) ; WEIRICH; Kristin
Marie; (Louisville, KY) |
Correspondence
Address: |
General Electric Company;GE Global Patent Operation
2 Corporate Drive, Suite 648
Shelton
CT
06484
US
|
Family ID: |
43379257 |
Appl. No.: |
12/877131 |
Filed: |
September 8, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12796776 |
Jun 9, 2010 |
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12877131 |
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12268090 |
Nov 10, 2008 |
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12796776 |
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Current U.S.
Class: |
62/82 ; 62/156;
62/186; 62/89 |
Current CPC
Class: |
F25C 1/00 20130101; F25D
21/08 20130101; F25D 17/065 20130101; F25D 23/04 20130101; F25B
2600/11 20130101; F25C 5/22 20180101 |
Class at
Publication: |
62/82 ; 62/186;
62/156; 62/89 |
International
Class: |
F25D 21/06 20060101
F25D021/06; F25D 17/06 20060101 F25D017/06 |
Claims
1. A refrigerator comprising: a main body defining a compartment,
the compartment having an access opening and a first wall; a door
supported by the main body for selectively closing at least part of
the access opening; a sub-compartment on the door, the
sub-compartment comprising a second wall having an opening; a heat
exchanger supported by the first wall and positioned so that when
the door is closed the heat exchanger is exposed to an interior of
the sub-compartment through the opening, the heat exchanger
comprising a heat exchanging plate; a sealed refrigeration system
containing a working medium for cooling the heat exchanger and
comprising one or more segments attached to the heat exchanging
plate; a fan configured to force air over the heat exchanging plate
and into the interior of the sub-compartment; a thermistor coupled
to the heat exchanging plate for monitoring a temperature of the
heat exchanging plate; and a controller configured to adjust a
speed of the fan in dependence of the temperature of the
heat-exchanging plate detected by the thermistor.
2. The refrigerator of claim 1, wherein the controller is
configured to adjust the speed of the fan to a low speed when the
detected temperature is below a pre-determined temperature
setpoint, and to a high speed when the detected temperature is
above the pre-determined temperature setpoint.
3. The refrigerator of claim 2, further comprising activating a
cooling cycle of the refrigeration system when the speed of the fan
is set to the high speed.
4. The refrigerator of claim 3, further comprising a wherein the
activation of the cooling cycle of the refrigeration system is
independent of a cooling requirement for the compartment of the
main body.
5. The refrigerator of claim 1, wherein the controller is
configured to detect an initiation of an ice formation cycle and
set a speed of the fan to high.
6. The refrigerator of claim 5, wherein the controller is
configured to activate the refrigeration system to cool the heat
exchanger when the speed of the fan is set to high.
7. The refrigerator of claim 5, wherein the controller is
configured measure an elapsed time from the initiation of the ice
formation cycle and set the speed of the fan to a low speed cycle
and the refrigeration system to a normal cooling cycle if the
elapsed time exceeds a pre-determined time period.
8. The refrigerator of claim 1, wherein the controller is
configured to detect that the refrigeration system is in a cooling
cycle, determine the temperature of the heat-exchanging plate and
adjust the speed of the fan to cool the interior of the
sub-compartment.
9. The refrigerator of claim 1, wherein the controller is further
configured to terminate a defrost cycle of the refrigerator in
dependence of the temperature detected by the thermistor.
10. A method comprising: detecting a temperature of a heat
exchanging plate in a bottom freezer refrigerator having an ice
sub-compartment on the door of a top mounted fresh food
compartment; and activating a fan for moving air across the heat
exchanging plate and into the ice sub-compartment in dependence of
the detected temperature.
11. The method of claim 10, further comprising adjusting a speed of
the fan to a low speed when the detected temperature is below a
predetermined temperature setpoint and adjusting the speed of the
fan to a higher speed when the detected temperature is above the
predetermined temperature setpoint.
12. The method of claim 11, further comprising detecting that the
detected temperature is above a second predetermined temperature
setpoint, setting the speed of the fan to a high speed and
activating a refrigeration system of the refrigerator.
13. The method of claim 12, further comprising that the activation
of the refrigeration system occurs independently of a temperature
requirement for a fresh food or freezer compartment of the
refrigerator.
14. The method of claim 10, further comprising activating the fan
only when a refrigeration system for the refrigerator is in a
cooling mode.
15. The method of claim 10, further comprising: detecting that a
state of an ice maker in the ice sub-compartment is in an ice
formation cycle; setting a speed of the fan to a high speed; and
activating a refrigeration system for the refrigeration to a
cooling mode.
16. The method of claim 15, further comprising: determining a
pre-determined time period from a start of the ice formation cycle;
and setting the speed of the fan in dependence of the detected
temperature.
17. The method of claim 10, further comprising using a single
thermistor coupled to the heat exchanging plate to detect the
temperature of the heat exchanging plate.
18. The method of claim 10, further comprising: detecting a defrost
mode of the heat-exchanging plate; and deactivating the defrost
mode when the temperature of the heat-exchanging plate reaches a
pre-determined defrost temperature setpoint.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 12/796,776, filed on Jun. 9, 2010,
which is a continuation-in-part application of application Ser. No.
12/268,090, filed on Nov. 10, 2008, the disclosures of which are
incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] The presently disclosed embodiments relate generally to a
refrigerator. More particularly, the disclosed embodiments relate
to a "bottom freezer" type refrigerator having an ice
sub-compartment on the door for the top mounted fresh food
compartment.
[0003] Generally, a refrigerator includes a freezer compartment and
a fresh food compartment which are partitioned from each other to
store various foods at low temperatures in appropriate states for a
relatively long time.
[0004] It is now common practice in the art of refrigerators to
provide an automatic icemaker. In a "side-by-side" type
refrigerator where the freezer compartment is arranged to the side
of the fresh food compartment, the icemaker is usually disposed in
the freezer compartment, and ice is delivered through an opening on
the door for the freezer compartment. In this arrangement, ice is
formed by freezing water with cold air in the freezer compartment,
the air being made cold by the refrigeration system of the
refrigerator, which includes an evaporator disposed in the freezer
compartment.
[0005] In a "bottom freezer" type refrigerator, where the freezer
compartment is arranged below a top mounted fresh food compartment,
convenience necessitates that the icemaker is disposed in a
thermally insulated compartment mounted on the door for the top
mounted fresh food compartment. Ice is dispensed through an opening
on the door of the fresh food compartment. In such an arrangement
provision must be made for providing adequate cooling to the ice
sub-compartment to enable the icemaker to form ice and for the ice
to be stored.
[0006] Generally, in a refrigerator where the ice-making section,
which includes an ice sub-compartment, is mounted on the door for
the fresh food compartment, the ice-making section can only make
ice when the compressor is running When the compressor is not
running, the ice-making section will typically be too warm to make
or store ice. The cooling or refrigeration system will generally
follow cooling cycles that are based on the temperatures of the
fresh food and the freezer compartments, meaning that the
compressor will run only in response to the temperature
requirements of the compartments. It would be advantageous to be
able to separately monitor and control the temperature of the
ice-making section in order to maintain the desired temperatures
during ice formation and ice storage cycles.
BRIEF DESCRIPTION OF THE INVENTION
[0007] As described herein, the exemplary embodiments overcome one
or more of the above or other disadvantages known in the art.
[0008] In one aspect, the presently disclosed embodiments are
directed to a refrigerator. In one embodiment, the refrigerator
includes a main body defining a compartment, the compartment having
an access opening and a first wall, a door supported by the main
body for selectively closing at least part of the access opening, a
sub-compartment on the door, the sub-compartment comprising a
second wall having an opening, a heat exchanger supported by the
first wall and positioned so that when the door is closed the heat
exchanger is exposed to an interior of the sub-compartment through
the opening. The heat exchanger includes a heat exchanging plate. A
sealed refrigeration system contains a working medium for cooling
the heat exchanger and has one or more segments attached to the
heat exchanging plate. A fan is configured to force air over the
heat exchanging plate and into the interior of the sub-compartment.
A thermistor is coupled to the heat exchanging plate for monitoring
a temperature of the heat exchanging plate. A controller is
configured to adjust a speed of the fan in dependence of the
temperature of the heat-exchanging plate detected by the
thermistor.
[0009] In another aspect, the disclosed embodiments are directed to
a method. In one embodiment, the method includes detecting a
temperature of a heat exchanging plate in a bottom freezer
refrigerator having an ice sub-compartment on the door of a top
mounted fresh food compartment; and activating a fan for moving air
across the heat exchanging plate and into the ice sub-compartment
in dependence of the detected temperature.
[0010] These and other aspects and advantages of the exemplary
embodiments will become apparent from the following detailed
description considered in conjunction with the accompanying
drawings. It is to be understood, however, that the drawings are
designed solely for purposes of illustration and not as a
definition of the limits of the invention, for which reference
should be made to the appended claims. Moreover, the drawings are
not necessarily drawn to scale and that, unless otherwise
indicated, they are merely intended to conceptually illustrate the
structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings:
[0012] FIG. 1 is a perspective view of a refrigerator in accordance
with an exemplary embodiment of the invention;
[0013] FIG. 2 is a perspective view of the refrigerator of FIG. 1
with the doors for the main fresh food compartment being open and
with the drawer/door for the freezer compartment being removed;
[0014] FIG. 3A partially and schematically shows some of the
components of the refrigerator of FIG. 1, with one of the fresh
food compartment doors open and the other being removed and the
door for the sub-compartment and the drawer/door for the freezer
compartment being removed;
[0015] FIG. 3B is a perspective, partial view of a fresh food
compartment door of the refrigerator of FIG. 2;
[0016] FIG. 4 is a partial schematic view of the heat exchanger and
the ice sub-compartment of the refrigerator of FIG. 2 with the
fresh food compartment door being closed;
[0017] FIG. 5 is an enlarged, schematic view of the heat exchanger
of FIG. 4;
[0018] FIG. 6 is an enlarged, schematic side view of a portion of
the fresh food compartment door, viewed along line 9-9 in FIG.
4;
[0019] FIG. 7 partially and schematically shows some of the
components of the refrigerator of FIG. 1 including a controller;
and
[0020] FIG. 8 is a flow diagram of an embodiment of a method
incorporating aspects of the present disclosure.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE
INVENTION
[0021] Referring to FIGS. 1 and 2, a refrigerator in accordance
with an exemplary embodiment of the invention is generally
designated by reference numeral 100. The aspects of the disclosed
embodiments are directed to controlling the temperature of the ice
making compartment 300 of a door bottom mount refrigerator
independently of the fresh food and freezer compartments 102,
104.
[0022] The refrigerator 100 has a main body 101 which defines
therein a first, upper fresh food compartment 102 with a frontal
access opening 102A, and a second, lower, freezer compartment 104
with a frontal access opening 104A. The fresh food compartment 102
and the freezer compartment 104 are arranged in a bottom mount
configuration where the fresh food compartment 102 is disposed or
positioned above the freezer compartment 104. The main fresh food
compartment 102 is shown with two French doors 134 and 135.
However, a single door or other suitable door arrangement can be
used instead of the doors 134, 135. The freezer compartment 104 can
be closed by a drawer or a door 132, as shown in FIG. 1.
[0023] As shown in FIG. 2, the main body 101 of the refrigerator
100 includes a top wall 230 and two sidewalls 232. The top wall 230
connects the sidewalls 232 to each other at the top ends thereof. A
mullion 233, best shown in FIG. 2, connects the two sidewalls 232
to each other and separates the main compartment 102 from the
freezer compartment 104. The main body 101 also includes a bottom
wall 234, which connects the two sidewalls 232 to each other at the
bottom ends thereof, and a back wall 235. As is known in the art,
at least each of the sidewalls 232 includes an outer case 232A, a
liner 232B, and a thermal insulation layer 232C disposed between
the outer case 232A and the liner 232B (see FIG. 5). The thermal
insulation layer 232C is made of a thermal insulation material such
as a rigid polyurethane or other thermoset foam.
[0024] The drawer/door 132 and the doors 134, 135 close the frontal
access openings 104A, 102A, respectively.
[0025] Each of the doors 134, 135 is mounted to the main body 101
by a top hinge 136 and a bottom hinge 138, thereby being rotatable
approximately around the outer vertical edge of the fresh food
compartment 102 between an open position for accessing the
respective part of the fresh food compartment 102, as shown in FIG.
2, and a closed position for closing the respective part of the
fresh food compartment 102, as shown in FIG. 1.
[0026] Similarly, when an access door 132 is used for the freezer
compartment 104, it is rotatably attached to the main body 101 in a
similar fashion. When a drawer is used for the freezer compartment
104, it is slidably received in the interior or cavity defined by
the freezer compartment 104 in a known fashion.
[0027] As shown in FIGS. 2-4, an ice-making section 300 for
freezing water and selectively discharging ice is mounted on the
door 134 for the fresh food compartment 102. The ice-making section
300 is disposed substantially in the fresh food compartment 102
when the door 134 is in the closed position. The ice-making section
300 delivers ice through a chute formed in the door 134. The chute
extends downward and/or outward from the ice-making section 300,
with its lower end 202 being accessible from the exterior surface
side of the door 134 (see FIG. 1). The lower end 202 is preferably
positioned at a height facilitating convenient access to the ice.
Of course, the ice-making section 300 can be mounted on the door
135 instead.
[0028] As illustrated in FIGS. 2 and 3A, the ice-making section 300
includes an ice sub-compartment 304 mounted on or partially formed
by the liner of the door 134. An icemaker 306 is disposed in the
sub-compartment 304. The ice-making section 300 preferably includes
an ice storage bin 308 disposed in the sub-compartment 304 and
below or underneath the icemaker 306. Since the fresh food
compartment 102 normally has a temperature higher than the freezing
point of water, the sub-compartment 304 is preferably thermally
insulated to prevent or substantially reduce undesired heat
transfer between air in the sub-compartment 304 and air in the
fresh food compartment 102. The sub-compartment 304 has a top wall
310, two sidewalls 312, 314, a bottom wall 316, a front wall 318,
and a back wall that can be formed by the inner liner of the door
134. As shown in FIG. 3B, preferably, the front wall 318 has an
opening 320, and an access door 322 is pivotably or rotatably
mounted to the front wall 318 in a known fashion for selectively
closing the opening 320. To facilitate cooling of the ice
sub-compartment 304, the sidewall 314 of the ice sub-compartment
304, which faces the sidewall 232S of the fresh food compartment
102 when the door 134 is closed, has an opening 314A. A gasket 317
is attached to the sidewall 314 and surrounds the opening 314A. The
function of the opening 314A and the gasket 317 will be discussed
in detail below.
[0029] Referring to FIG. 7, as is known in the art, water is
delivered to one or more ice molds (not shown) of the icemaker 306
and then frozen into ice cubes. The water supply 401 is controlled
by a valve 402. After the water is frozen into ice cubes, the ice
cubes may be discharged from the ice molds and stored in the ice
storage bin 308 until needed by a user. The ice cubes may be
dispensed or withdrawn by accessing the ice storage bin 308 through
the access door 322. The ice cubes, however, are typically
dispensed via a chute by an ice-dispensing device, such as an auger
or other mechanical device (not shown), installed in the door
134.
[0030] Referring now to FIG. 3A, in one embodiment, the
refrigeration system 350 of the refrigerator 100 is preferably a
single evaporator system. The system 350 includes evaporator 352
disposed in the freezer compartment 104, a compressor 354 disposed
downstream of the evaporator 352 and outside of the freezer
compartment 104, a condenser 356 disposed downstream of the
compressor 354, an expansion valve 358 disposed downstream of the
condenser 356, and a fluid connection loop 360 fluidly connecting
these elements 352-358 together. The refrigeration system 350
contains therein a working medium (i.e., the refrigerant). Unlike
known refrigerators, however, the fluid connection loop 360, which
connects the evaporator 352 to the compressor 354 for transmitting
the refrigerant, includes a serpentine portion 360A (i.e., the
cooling serpentine) disposed or embedded in the sidewall 232S of
the fresh food compartment 102 at a location proximate to the
opening 314A in door 134 when the door 134 is closed. By this
arrangement, the serpentine portion 360A can be used to cool the
ice sub-compartment 304 as hereinafter described.
[0031] As shown in FIG. 5, the liner 232B of the sidewall 232S of
the fresh food compartment 102 has an opening 372 that preferably
faces or is substantially aligned with the opening 314A of the
sidewall 314 of the sub-compartment 304 when the door 134 is in the
closed position. In one embodiment, a heat exchanger 370, which
includes a formed metal heat-exchanging plate 374, is attached to
the liner 232B and covers the opening 372. The heat exchanger 370
is thermally coupled to the serpentine portion 360A of the fluid
connection loop 360 so that the refrigerant, when passing through
the serpentine portion 360A, cools the heat-exchanging plate 374.
When the door 134 is closed, the heat-exchanging plate 374 is
substantially aligned with the opening 314A. The gasket 317
touches/presses the sidewall 232S and surrounds the heat-exchanging
plate 374 so that the heat-exchanging plate 374 is exposed to the
interior of the sub-compartment 304, while the gasket 317
substantially seals the heat-exchanging plate 374 and the interior
of the ice maker compartment 304 from the rest of the fresh food
compartment 102. In other words, when the door 134 is closed, part
of the sidewall 232S including the heat-exchanging plate 374, the
gasket 317 and the sub-compartment 304 form or define a
substantially sealed interior space.
[0032] Referring still to FIGS. 3A-5, preferably, the serpentine
portion 360A of the fluid connection loop 360 has a plurality of
bent sections 361. The heat-exchanging plate 374 preferably has a
plurality of projections 376 which extend outward from its first,
exposed surface 374E. Preferably, each of the projections 376 has a
curved cross-section (substantially semi-spherical cross sections
are shown in FIG. 5, so that the projections 376 also define
receiving channels 376R on the second, un-exposed, foam-facing
surface 374U of the heat-exchanging plate 374 for receiving the
respective bent sections 361. Such projections 376 enhance not only
the heat exchange between the bent sections 361 and the
heat-exchanging plate 374, but also the heat exchange between the
heat-exchanging plate 374 and the air in the ice sub-compartment
304.
[0033] As shown in FIGS. 4 and 5, an appearance enhancing louvered
cover 380 is preferably used to cover the heat-exchanging plate
374. The louvered cover 380, which is supported by the liner 232B,
is spaced apart from the heat-exchanging plate 374.
[0034] Referring to FIG. 5, in one embodiment, a defrost heater 378
can be thermally coupled to the heat-exchanging plate 374 to remove
frost that may form on the exposed surface of the heat-exchanging
plate 374. In one embodiment, the defrost heater 378 is an aluminum
foil defrost heater comprising foil layer 378A and resistive heater
coils 378B. In alternate embodiments, the defrost heater 378 can
comprise any suitable heater for warming the heat-exchanging plate
374. In this embodiment, the bent sections 361 of the serpentine
portion 360A are sandwiched between the heat-exchanging plate 374
and a layer of aluminum foil that overlays the foam-facing surface
374U of plate 374. A drain tube 382 (shown in FIG. 4), preferably
embedded in the sidewall, with an inlet proximate the lower end of
the heat-exchanging plate 374, is provided for directing the
defrost water to a drain pan (not shown) which may be the
evaporator drain pan. As shown in FIG. 5, a scoop 384 is located
proximate the lower ends of the heat-exchanging plate 374 and the
louvered cover 380 for directing the defrost water from the
heat-exchanging plate 374 and the louvered cover into the drain
tube 382. The scoop 384 may have a configuration that covers the
entire width of the heat-exchanging plate 374 and the entire width
of the louvered cover 380. Preferably the scoop 384 is made of a
flexible material such as rubber or soft plastic so as to not
interfere with the door foaming process.
[0035] Referring now to FIGS. 5-7, an electric fan 390 is located
in the ice sub-compartment 304 for facilitating the heat exchange
between the air in the ice sub-compartment 304 and the
heat-exchanging plate 374 when the door 132 is closed. Preferably,
the fan is disposed adjacent to the opening 314A. As shown in FIGS.
6 and 7, a louvered fan bracket 392 is preferably used to at least
partially cover the opening 314A and to support the fan 390. The
fan 390 directs air in the direction A towards the exposed surface
of heat-exchanging plate 374. As the air then moves over the
exposed surface of the plate 374, cooled by the coolant passing
through the cooling serpentine 360A, heat is absorbed by the plate
374 and the chilled air recirculates through the ice
sub-compartment 304. By this arrangement, the air in the ice
sub-compartment 304 is chilled sufficiently to form ice in the
icemaker during an ice forming cycle and maintain a freezing
temperature during an ice storage cycle.
[0036] The icemaker 306, the defrost heater 378 and the fan 390 may
be powered by a common power source or by a dedicated power source
of their own.
[0037] The aspects of the disclosed embodiments are directed to
controlling the temperature of the heat-exchanging plate 374 of a
door bottom mount refrigerator 100 for ice formation, ice storage
and defrost cycles. A single thermistor located on the
heat-exchanging plate 374 is used to determine a cooling fan speed
for the ice sub-compartment 304 as well as determine the time to
terminate a defrost cycle of the heat-exchanging plate 374.
[0038] In one embodiment, the temperature of the heat-exchanging
plate 374 is used as an indirect indicator of the temperature of
the ice making section 300, and in particular the ice
sub-compartment 304. As described above, the circulation of the
refrigerant through the serpentine portion 360A causes the
heat-exchanging plate 374 to cool and the fan 390 forces air across
the heat-exchanging plate 374. The cooled air is directed into the
ice sub-compartment 304, which causes the ice sub-compartment 304
to cool. As such, the sensed temperature of the heat-exchanging
plate 374 can be used as an indirect measure of the temperature of
ice sub-compartment 304. An inference is made that the temperature
of the ice sub-compartment 304 corresponds relatively to the
temperature of the heat-exchanging plate 374.
[0039] In one embodiment, as shown in FIGS. 3A and 7, a thermistor
405 is thermally coupled to the heat-exchanging plate 374. The
thermistor 405 is used to monitor or detect the temperature of the
heat-exchanging plate 374 and generally comprises a heat sensing
device, such as for example, a thermocouple. In alternate
embodiments, the thermistor 405 can comprise any suitable heat
detecting device or sensor that is configured to detect a relative
temperature of an object. The temperature of the heat-exchanging
plate 374 will herein be referred to as temperature T.
[0040] Generally, in a refrigerator 100 where the ice-making
section 300 is mounted on the door 134 for the fresh food
compartment 102, the ice-making section 300 can only make ice when
the compressor 354 is running When the compressor 354 is not
running, the ice sub-compartment 304 will typically be too warm to
make or store ice. The cooling or refrigeration system 350 will
generally follow cooling cycles that are based on the temperatures
of the fresh food 102 and the freezer compartments 104, meaning
that the compressor 354 will run only in response to the
temperature of the compartments 102, 104. However, because the ice
sub-compartment 304 is separate from the fresh food and freezer
compartments 102, 104, the temperature of the ice sub-compartment
needs to be separately monitored and controlled in order to
maintain the desired temperatures during ice formation and ice
storage cycles.
[0041] The aspects of the disclosed embodiments allow for the
monitoring and control of the temperature of the ice
sub-compartment 304 independently of compartments 102, 104. In
addition, temperature T as monitored by thermistor 405, is used to
control the speed of fan 390 and the independent control of the
compressor 354, even when the fresh food compartment 102 and the
freezer compartment 104 do not require cooling. This independent
monitoring and control of the temperature of ice sub-compartment
304 enables the ice sub-compartment 304 to maintain suitably cold
temperatures during ice forming and ice storage cycles.
[0042] During an ice formation cycle, it is desirable to maintain
temperatures in the ice sub-compartment 304 well below freezing,
such as in the range of approximately 0 to 10 degrees Fahrenheit.
In alternate embodiments, the temperature of the ice
sub-compartment 304 during an ice formation cycle can be any
suitable freezing temperature. When the compressor 354 is running,
the temperature of the heat exchanging plate 374 will generally be
colder than the ice sub-compartment 304. Increasing the speed of
the fan 390 in this state or cycle will increase the heat transfer
across the heat exchanging plate 374 and correspondingly reduce the
temperature of the ice sub-compartment 304. Thus, in order to
optimize the heat transfer and cooling during the ice formation
cycle, the speed of the fan 390 is set to a high speed while the
compressor 354 is running.
[0043] Thermistor 405 can be used during the ice formation cycle to
monitor the temperature of the heat-exchanging plate 374 to ensure
that the temperature remains in a suitable freezing range for ice
formation. Temperature T of the heat-exchanging plate 374 during
ice formation can also be used to run compressor 354 even when
compartments 102, 104 do not require cooling, and to increase or
decrease fan speed to ensure that an appropriate temperature is
maintained for ice formation in the ice sub-compartment 304.
[0044] When the ice-making section 300 is not in the ice formation
cycle, the ice-making section 300 will typically be in an ice
storage cycle. In this state, the temperature of the ice
sub-compartment 304 can be maintained at a temperature that is
warmer than the freezing temperature range for ice formation. In
one embodiment, a desired temperature of the ice sub-compartment
304 during the ice storage cycle is approximately 20 degrees
Fahrenheit. In the ice storage cycle, when the heat exchanging
plate 374 is cold, or in the range of 0 to 10 degrees Fahrenheit,
or such other suitable freezing temperature, the inference is made
that the temperature of the ice sub-compartment 304 is in the range
of a suitable freezing temperature and does not require additional
cooling. The fan 390 can be set to run at a slow speed and/or cycle
off. When the temperature of the heat exchanging plate 374 is
warmer than 0 to 10 degrees Fahrenheit, the fan 390 can be set to
run at a higher speed in order to provide additional cooling to the
ice sub-compartment 304. When the temperature T exceeds a
pre-determined temperature setpoint, such as for example, 20
degrees Fahrenheit, the speed of the fan 390 can be set to high,
and the compressor 354 activated.
[0045] In one embodiment, both during ice formation and ice
storage, when the fan 390 is activated or turned on, the compressor
354 will also be on, or activated. The activation of the compressor
354 can occur whenever the fan 390 comes on or only when the speed
of the fan 390 is set to high. In one embodiment, the speed of the
fan 390 can be adjusted across a range, where the speed of the fan
390 increases as the temperature T of the heat-exchanging plate 374
increases. Once the compressor 354 is activated, the temperature of
the heat-exchanging plate 374 will decrease. The speed of the fan
390 can be accordingly adjusted to lower speeds as the temperature
of the heat-exchanging plate 374 decreases, depending upon the
cooling and temperature requirement for the ice sub-compartment 304
at the time.
[0046] In one embodiment, the temperature reading of the thermistor
405 from the heat-exchanging plate 374 is also used to control and
terminate a defrost cycle of the refrigerator 100. When the defrost
cycle is initiated, the defrost heater 378 is energized to warm the
heat-exchanging plate 374 in order to melt any frost build-up or
accumulation from the heat-exchanging plate 374. The defrost heater
378 can be de-energized when the temperature reading of the
thermistor 405 indicates that the temperature of the
heat-exchanging plate is above the freezing point or other
pre-determined temperature set point, such as for example 40
degrees Fahrenheit. Alternatively, the defrost heater can be
de-energized at any suitable point where it can be determined that
all of the frost has melted.
[0047] In one embodiment, the defrost heater 378 remains energized
until the temperature of the heat-exchanging plate 374, as detected
by the thermistor 405 is at a suitable temperature setpoint above
the freezing point, or a pre-determined time period has elapsed. It
may be desirable to control the length of time that the defrost
heater 378 remains energized, in the event that the thermistor 405
malfunctions or becomes disconnected. Thus, in one embodiment, in
addition to controlling the defrost cycle based on the temperature
of the heat-exchanging plate 374, a maximum time period for the
defrost heater 378 to remain energized will also be set.
[0048] Since the temperature of the heat-exchanging plate 374 is
measured remotely from the ice sub-compartment 304, the temperature
of the ice sub-compartment 304 cannot be obtained directly from the
reading of thermistor 405. Generally, the temperature of the
heat-exchanging plate 374 will be colder than the temperature of
the ice sub-compartment 304 when the compressor 354 and fan 309 are
running In one embodiment, the temperature difference can be
approximately 10 degrees Fahrenheit. In one embodiment, an estimate
of the temperature of the ice sub-compartment 304 is based on the
reading of the thermistor 405. The estimate can take into account
any one or more factors or parameters that may affect the
correlation of temperature readings from the temperature of the
heat-exchanging plate 374 to the ice sub-compartment 304. In one
embodiment, these parameters can include, for example, the average
of the readings from thermistor 405, a delay or offset factor, the
freezer temperature and the ambient air temperature. In alternate
embodiments, any suitable environmental or other factor that may
affect the temperature reading of the thermistor 405 can be
considered in estimating the temperature of the ice sub-compartment
304.
[0049] In one embodiment, the temperature readings of the
thermistor 405 are averaged over a specific time period or time
duration. The averaging may be performed while the fan 390 is
running to lessen the direct effect of the heat-exchanging plate
374 on the thermistor 405.
[0050] The temperature of the freezer compartment 104 will also
have an effect on the temperature reading of the thermistor 405. In
one embodiment, the average temperature of the heat exchanging
plate 374 can be a function of the temperature of the freezer
compartment 104, since when the compressor 354 is running, the
refrigerant is circulating through the serpentine portion 360A, and
having a cooling effect on the heat-exchanging plate 374. In one
embodiment, the temperature of the freezer compartment 104 is
factored into the estimate of the temperature of the ice
sub-compartment 304 from the temperature reading by the thermistor
405.
[0051] Additionally, in one embodiment, the ambient temperature
outside the refrigerator 100 can be factored into the algorithm for
estimating the temperature of the ice sub-compartment 304 from the
reading of the thermistor 405. Generally, the ambient temperature
will affect the heat leakage into the fresh food and freezer
compartments 102, 104. This leakage can affect the temperature
reading by the thermistor 405. Each of these factors can be taken
into account when estimating the temperature of the ice
sub-compartment 304 from the temperature reading by the thermistor
405. In one embodiment, a look-up table can be constructed based on
known or predetermined relationships between the temperature
reading of the thermistor 405 from the heat-exchanging plate 374
and the temperature of the ice sub-compartment 304.
[0052] FIG. 7 illustrates an example of one embodiment of a
refrigerator 100 that includes a controller 410 that can be used
for controlling the refrigerator 100 in accordance with the aspects
of the disclosed embodiments. In this embodiment, controller 410 is
configured to control the various functions of the refrigerator 100
and the ice making section 300 in response to the sensed
temperature T of the heat exchanging plate 374, and other
operational events and environmental effects. Although the
controller 410 is shown in this example as a separate subsystem of
the refrigerator 100, in one embodiment, the controller 410 is
embodied as an integral component of the refrigerator 100.
[0053] In one embodiment, the icemaker 306 obtains water for
preparing ice cubes from water supply 401 though an appropriate
valve 402. The icemaker 306 can include a sensor 403A that is
configured to detect the actuation of the valve 402 for filling the
ice molds (not shown) of the icemaker 306. In one embodiment, the
sensor 403A comprises a water flow sensor that detects the flow of
water through the valve or the opening of the valve. Signal 404A
that is generated by sensor 403A can be used by the controller 410
to determine that the icemaker 306 is in an ice formation cycle. As
previously noted, the dispensing of ice from the icemaker 306 can
also be used as an indication to activate the ice formation cycle.
In one embodiment, the icemaker 306 includes a sensor 403B that is
configured to detect the movement of the auger (not shown) for
dispensing ice. The sensor 403B can comprise a Hall effect sensor,
or such other suitable sensor that is configured to detect movement
of the auger, or an activation switch that detects the activation
of the ice dispenser. Signal 404B generated by sensor 403B can be
used by the controller 404 as an indication to initiate an ice
formation cycle as is described herein.
[0054] In one embodiment, the controller 410 is electrically
coupled to the fan 390 and refrigeration system 350. The controller
410 is configured to provide a speed control signal 404C to the fan
390. The speed control signal 390 is used to adjust and set the
speed of the fan 390 in accordance with the embodiments disclosed
herein. For example, when the controller 410 detects the initiation
of the ice formation mode, the controller 410 can activate the
refrigeration system 350 and set the speed of the fan 390 to high.
Generally, the initiation of the ice formation cycle will override
the control of the refrigeration system 350 by the fresh food and
freezer compartments 102, 104. The controller 410 can enable the
refrigeration system 350, and in particular compressor 354, to run
even though the temperatures of the fresh food and freezer
compartments 102, 104 do not call for additional cooling. In one
embodiment, the controller 410 is configured to control the
components of the refrigeration system 350 to avoid overcooling of
the fresh food or freezer compartments 102, 104, when the heat
exchanger 370 is being cooled.
[0055] The thermistor 405 is mounted at the heat-exchanging plate
374, and suitably positioned to detect the temperature T of the
heat-exchanging plate 374. In one embodiment, the thermistor 405 is
configured to generate a signal 404D that can be used by the
controller 410 to determine a temperature of the heat exchanging
plate 374.
[0056] FIG. 8 illustrates one example of a process flow
incorporating aspects of the disclosed embodiments. In one
embodiment, it is determined 801 whether an ice formation cycle is
active or an elapsed time period since a last activation of the ice
formation cycle is greater than a pre-determined time period. The
pre-determined time period can be any suitable time period, such as
for example, two hours. Generally, the pre-determined time period
is a period during which ice will form or harden during an ice
formation cycle.
[0057] If the ice formation cycle is active or less than two hours
has elapsed since the activation of the ice formation cycle, the
state 810 of the fan 390 set to high and the compressor 354 is set
to on.
[0058] If the ice formation cycle is not active and the elapsed
time period exceeds the pre-determined time period, an ice storage
cycle or mode 802 of the ice-making section 300 is enabled. In one
embodiment, in the ice storage cycle, a speed of the fan 390 is
initially set to a low speed or off. The speed of the fan 390 can
also be cycled on and off according to a pre-determined duty cycle,
such as for example, approximately 50%. In one embodiment, in the
ice storage mode, the cycles of the compressor 354 will generally
correspond to the typical cooling cycles that are based on the
temperature requirements of the fresh food 102 and the freezer
compartments 104. In this state, when the compressor 354 cycles on
due to a call from the fresh food or freezer compartments 102, 104,
the heat-exchanging plate 374 will also be cooled. If the fan 390
runs during this period, cooling will be provided to the ice
sub-compartment 304 as described above.
[0059] In the ice storage mode 802, once the fan 390 is set to low
or off, the temperature T of the heat-exchanging plate 374 is
monitored by thermistor 405. In one embodiment, it is determined
804 if the temperature of the heat exchanging plate 374 is in the
range of approximately 0-10 degrees Fahrenheit. If yes, the speed
of the fan 390 remains at the low, off or cycling setting 805. If
the temperature of the heat exchanging plate 374 exceeds the range
of 0-10 degrees Fahrenheit, the speed of the fan 390 can be
increased at 806. In one embodiment, the speed of the fan 390 can
be increased incrementally over a range from low to high and can be
adjusted relative to the detected temperature. For example, in one
embodiment, if the temperature is in the range of 0-10 degrees, the
speed of the fan 390 can be set to off, or cycled on/off as
described above. If the temperature is in a range of approximately
10-15 degrees Fahrenheit, the speed of the fan 390 can be increased
to a mid-level speed. A high speed setting of the fan 390 can be
activated when the temperature T is at or above approximately 20
degrees Fahrenheit.
[0060] Correspondingly, if the temperature T decreases, the speed
of the fan 390 can be reduced. For example, if the temperature T
falls below 10 degrees Fahrenheit, the setting of the fan 390 can
be adjusted to be off or in the cycling state 805. If it is
determined 809 that the temperature T remains less than
approximately 20 degree Fahrenheit, or in the range of 10 to 20
degrees Fahrenheit, the speed of the fan 390 can continue to be
adjusted 806 accordingly. If the temperature exceeds approximately
20 degrees Fahrenheit, the fan 390 and compressor 354 can be set to
the high/on state 810.
[0061] In one embodiment, the fan 390 will only be on when the
compressor 354 is on. When the compressor 354 is on, the
heat-exchanging plate 374 will be cooled by the circulating working
medium. Generally, when the compressor 354 is on, the temperature T
of the heat-exchanging plate 374 will be cooler than the ice
sub-compartment 304.
[0062] The disclosed embodiments may also include software and
computer programs incorporating the process steps and instructions
described above. In one embodiment, the programs incorporating the
process described herein can be stored on or in a computer program
product and executed in one or more computers. The controller 410
illustrated in FIG. 7 can include computer readable program code
means stored on a computer readable storage medium, such as a
memory for example, for carrying out and executing the process
steps described herein. In one embodiment, the computer readable
program code is stored in a memory of the apparatus 700. In
alternate embodiments, the computer readable program code can be
stored in memory or memory medium that is external to, or remote
from, the controller 410. The memory can be direct coupled or
wireless coupled to the controller 410.
[0063] The controller 410 may be linked to another computer system
or controller (not shown), such that the controllers are capable of
sending information to each other and receiving information from
each other. In one embodiment, the controller 410 could include a
server computer or controller adapted to communicate with a
network, such as for example, a wireless network or the
Internet.
[0064] The controller 410 is generally adapted to utilize program
storage devices embodying machine-readable program source code,
which is adapted to cause the controller 410 to perform the method
steps and processes disclosed herein. The program storage devices
incorporating aspects of the disclosed embodiments may be devised,
made and used as a component of a machine utilizing optics,
magnetic properties and/or electronics to perform the procedures
and methods disclosed herein. In alternate embodiments, the program
storage devices may include magnetic media, such as a diskette,
disk, memory stick or computer hard drive, which is readable and
executable by a computer. In other alternate embodiments, the
program storage devices could include optical disks,
read-only-memory ("ROM") floppy disks and semiconductor materials
and chips.
[0065] The controller 410 may also include a microprocessor for
executing stored programs, and may include a data storage or memory
device on its program storage device for the storage of information
and data. The computer program or software incorporating the
processes and method steps incorporating aspects of the disclosed
embodiments may be stored in one or more computer systems or on an
otherwise conventional program storage device.
[0066] The aspects of the disclosed embodiments are directed to
controlling the temperature of the heat-exchanging plate 374 of a
door bottom mount refrigerator 100 for ice formation, ice storage
and defrost cycles. A single thermistor located on the
heat-exchanging plate 374 is used to determine a cooling fan speed
for the ice sub-compartment 304 as well as determine the time to
terminate a defrost cycle of the heat-exchanging plate 374. The
monitoring and control of the temperature of the ice
sub-compartment 304 is carried out independently of the fresh food
and freezer compartments 102, 104.
[0067] Moreover, it is expressly intended that all combinations of
those elements and/or method steps which perform substantially the
same function in substantially the same way to achieve the same
results are within the scope of the invention. Moreover, it should
be recognized that structures and/or elements and/or method steps
shown and/or described in connection with any disclosed form or
embodiment of the invention may be incorporated in any other
disclosed or described or suggested form or embodiment as a general
matter of design choice. It is the intention, therefore, to be
limited only as indicated by the scope of the claims appended
hereto.
* * * * *