U.S. patent application number 12/457807 was filed with the patent office on 2010-05-27 for cooling system and method of controlling the same.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Hyen Young Choi, Jeong Su Han, Jung Hyeon Kim, Sang Jun Lee, O Do Ryu, Kook Jeong Seo, Ho Yoon.
Application Number | 20100126191 12/457807 |
Document ID | / |
Family ID | 42046396 |
Filed Date | 2010-05-27 |
United States Patent
Application |
20100126191 |
Kind Code |
A1 |
Han; Jeong Su ; et
al. |
May 27, 2010 |
Cooling system and method of controlling the same
Abstract
An oscillatory wave generating unit and an oscillatory wave
sensing unit are installed at both ends of a refrigerant pipe of an
evaporator of the cooling system, an amount of frost formed on the
refrigerant pipe is determined by comparing a wave form of an
oscillatory wave generated from one end of the refrigerant through
the oscillatory wave generating unit and a wave form of the
oscillatory wave sensed by the other one end of the refrigerant
through the oscillatory wave sensing unit, and whether or not a
defrosting operation is performed is determined by a result of the
determination. The cooling system increases the accuracy in sensing
the amount of the frost formed on the evaporator of a refrigerator,
a Kimchi refrigerator, or an air conditioner, and respectively
starts and ends the defrosting operation at proper points of time,
thus enhancing a heat-exchanging performance and increasing energy
efficiency.
Inventors: |
Han; Jeong Su; (Suwon-si,
KR) ; Lee; Sang Jun; (Suwon-si, KR) ; Seo;
Kook Jeong; (Osan-si, KR) ; Yoon; Ho;
(Yongin-si, KR) ; Kim; Jung Hyeon; (Hwaseong-si,
KR) ; Choi; Hyen Young; (Suwon-si, KR) ; Ryu;
O Do; (Suwon-si, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700, 1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
42046396 |
Appl. No.: |
12/457807 |
Filed: |
June 22, 2009 |
Current U.S.
Class: |
62/80 ;
62/151 |
Current CPC
Class: |
F25B 2700/111 20130101;
F25D 21/02 20130101 |
Class at
Publication: |
62/80 ;
62/151 |
International
Class: |
F25D 21/02 20060101
F25D021/02; F25D 21/06 20060101 F25D021/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2008 |
KR |
10-2008-117363 |
Claims
1. A cooling system comprising: an oscillatory wave generating unit
installed at one end of a refrigerant pipe and generating an
oscillatory wave; an oscillatory wave sensing unit installed at the
other end of the refrigerant pipe and sensing the oscillatory wave;
and a control unit determining an amount of frost formed on the
refrigerant pipe based on a difference of wave forms between the
oscillatory wave generated from the oscillatory wave generating
unit and the oscillatory wave sensed by the oscillatory wave
sensing unit.
2. The cooling system according to claim 1, wherein the difference
of wave forms is a phase difference between the oscillatory wave
generated from the oscillatory wave generating unit and the
oscillatory wave sensed by the oscillatory wave sensing unit.
3. The cooling system according to claim 1, wherein the difference
of wave forms is an amplitude difference between the oscillatory
wave generated from the oscillatory wave generating unit and the
oscillatory wave sensed by the oscillatory wave sensing unit.
4. The cooling system according to claim 1, wherein the control
unit controls a defrosting operation based on the amount of
frost.
5. The cooling system according to claim 4, wherein the control
unit determines an amount of frost remaining on the refrigerant
pipe based on the difference of wave forms in the defrosting
operation, and determines whether or not the defrosting operation
is terminated based on the amount of the remaining frost.
6. A cooling system comprising: a plurality of oscillatory wave
generating units installed on a refrigerant pipe and generating
oscillatory waves; a plurality of oscillatory wave sensing units
installed on the refrigerant pipe corresponding to the plurality of
oscillatory wave generating units and sensing the oscillatory
waves; and a control unit determining amounts of frost formed in
sections of the refrigerant pipe based on differences of wave forms
between the oscillatory waves generated from the oscillatory wave
generating units and the oscillatory waves sensed by the
oscillatory wave sensing units.
7. The cooling system according to claim 6, wherein the plurality
of oscillatory wave generating units sequentially generates the
oscillatory waves.
8. The cooling system according to claim 6, wherein: the
refrigerant pipe is divided into plural sections; and the plurality
of oscillatory wave generating units are respectively installed at
ends of the sections and the plurality of oscillatory wave sensing
units are respectively installed at the other ends of the
sections.
9. The cooling system according to claim 6, wherein the differences
of wave forms are phase differences between the oscillatory waves
generated from the plurality of oscillatory wave generating units
and the oscillatory waves sensed by the plurality of oscillatory
wave sensing units.
10. The cooling system according to claim 6, wherein the
differences of wave forms are amplitude differences between the
oscillatory waves generated from the plurality of oscillatory wave
generating units and the oscillatory waves sensed by the plurality
of oscillatory wave sensing units.
11. The cooling system according to claim 6, wherein the control
unit controls a defrosting operation based on the amounts of the
frost in respective sections.
12. The cooling system according to claim 11, wherein the control
unit determines amounts of frost remaining in the sections of the
refrigerant pipe in the defrosting operation, and determines
whether or not the defrosting operation is completed based on the
amounts of the remaining frost.
13. The cooling system according to claim 6, wherein the control
unit performs the defrosting operation when the amount of frost in
at least one section of the sections is more than a reference
amount.
14. A method of controlling a cooling system, comprising:
generating an oscillatory wave by operating an oscillatory wave
generating unit installed at one end of a refrigerant pipe; sensing
the oscillatory wave by an oscillatory wave sensing unit installed
at the other end of the refrigerant pipe; and determining an amount
of frost formed on the refrigerant pipe based on a difference of
wave forms between the generated oscillatory wave and the sensed
oscillatory wave.
15. The method according to claim 14, wherein the determination of
the amount of frost includes calculating a phase difference between
the generated oscillatory wave and the sensed oscillatory wave.
16. The method according to claim 14, wherein the determination of
the amount of frost includes calculating an amplitude difference
between the generated oscillatory wave and the sensed oscillatory
wave.
17. The method according to claim 14, further comprising
determining whether or not it is a defrosting time point based on
the amount of the frost formed on the refrigerant pipe.
18. The method according to claim 17, further comprising:
performing a defrosting operation, when it is determined that it is
the defrosting time point; determining an amount of frost remaining
on the refrigerant pipe by generating an oscillatory wave and
sensing the oscillatory wave; and determining whether or not it is
a defrosting operation ending time point based on the amount of the
remaining frost.
19. A method of controlling a cooling system, comprising:
generating oscillatory waves by operating a plurality of
oscillatory wave generating units; sensing the oscillatory waves by
a plurality of oscillatory wave sensing units corresponding to the
plurality of oscillatory wave generating units; and determining
amounts of frost formed in sections of a refrigerant pipe based on
differences of wave forms between the generated oscillatory waves
and the sensed oscillatory waves.
20. The method according to claim 19, wherein the generation of the
oscillatory waves includes sequentially operating the plurality of
oscillatory wave generating units.
21. The method according to claim 19, wherein the sensing of the
oscillatory waves includes: dividing the refrigerant pipe into
plural sections; and respectively sensing the oscillatory waves in
the sections of the refrigerant pipe.
22. The method according to claim 19, wherein the determination of
the amounts of frost includes calculating phase differences between
the generated oscillatory waves and the sensed oscillatory
waves.
23. The method according to claim 19, wherein the determination of
the amounts of frost includes calculating amplitude differences
between the generated oscillatory waves and the sensed oscillatory
waves.
24. The method according to claim 19, further comprising
determining whether or not it is a defrosting time point based on
the amounts of frost formed in the sections of the refrigerant
pipe.
25. The method according to claim 24, further comprising:
performing a defrosting operation, when it is determined that it is
the defrosting time point; determining amounts of frost remaining
in the sections of the refrigerant pipe by generating oscillatory
waves and sensing the oscillatory waves; and determining whether or
not it is a defrosting operation ending time point based on the
amounts of the remaining frost.
26. The method according to claim 19, further comprising:
respectively comparing the amounts of frost in the sections with a
reference amount; and performing the defrosting operation, when the
amount of frost in at least one section of the sections is more
than the reference amount.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2008-0117363, filed on Nov. 25, 2008, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a cooling system and a
method of controlling the same, and more particularly to a cooling
system, which senses frost formed on an evaporator by heat
exchange, and a method of controlling the cooling system.
[0004] 2. Description of the Related Art
[0005] In general, cooling systems are apparatuses, which circulate
a refrigerant according to a refrigerating cycle and thus cool a
designated space, and include a refrigerator, a Kimchi
refrigerator, an air conditioner, etc.
[0006] Here, the refrigerating cycle changes a refrigerant into
four phases, such as compression, condensation, expansion, and
evaporation, and thus needs to be provided with a compressor, a
condenser, an expansion valve, an evaporator, etc. That is, when
the refrigerant in a gas state is compressed by the compressor and
is transmitted to the condenser, the compressed refrigerant
exchanges heat with surrounding air in the condenser and thus is
cooled. Thereafter, when the refrigerant in a liquid state obtained
by cooling is injected into the evaporator under the condition that
the flow rate of the refrigerant is adjusted by the expansion
valve, the refrigerant is rapidly expanded and evaporated, and thus
absorbs heat from surrounding air in the evaporator and supplies
cold air to an indoor space, such as the interior of a room,
thereby cooling the space. Thereafter, when the refrigerant in the
gas state obtained in the evaporator is transmitted again to the
compressor, the refrigerant in the gas state is compressed again
into the refrigerant in the liquid state, and the above
refrigerating cycle is repeated.
[0007] Since the surface temperature of the evaporator cooling the
indoor space through the refrigerating cycle is lower than the
temperature of air in the indoor space, moisture condensed from the
air of a relatively higher temperature in the indoor space is stuck
to the surface of the evaporator and thus frost is formed on the
surface of the evaporator. The frost formed on the surface of the
evaporator is gradually thickened as time goes by, and then the
heat-exchanging efficiency of air passing through the evaporator is
lowered and causes excessive power consumption.
[0008] In order to solve the problem, a defrosting operation, in
which the operating time of the compressor is accumulated, and a
heating unit installed around the evaporator is operated to remove
the frost formed on the surface of the evaporator, when the
accumulated operating time elapses a designated time, was
conventionally performed. However, this defrosting operation is
performed based on the operating time of the compressor regardless
of the real amount of the front formed on the surface of the
evaporator, and thus is limited in the effective removal of the
frost formed on the surface of the evaporator.
SUMMARY
[0009] Therefore, one aspect of the invention is to provide a
cooling system, which senses frost formed on an evaporator by heat
exchange, and a method of controlling the cooling system.
[0010] Additional aspects and/or advantages will be set forth in
part in the description which follows and, in part, will be
apparent from the description, or may be learned by practice of the
invention.
[0011] In accordance with one aspect, the present invention
provides a cooling system including an oscillatory wave generating
unit installed at one end of a refrigerant pipe and generating an
oscillatory wave; an oscillatory wave sensing unit installed at the
other end of the refrigerant pipe and sensing the oscillatory wave;
and a control unit determining an amount of frost formed on the
refrigerant pipe based on a difference of wave forms between the
oscillatory wave generated from the oscillatory wave generating
unit and the oscillatory wave sensed by the oscillatory wave
sensing unit.
[0012] The difference of wave forms may be a phase difference
between the oscillatory wave generated from the oscillatory wave
generating unit and the oscillatory wave sensed by the oscillatory
wave sensing unit.
[0013] The difference of wave forms may be an amplitude difference
between the oscillatory wave generated from the oscillatory wave
generating unit and the oscillatory wave sensed by the oscillatory
wave sensing unit.
[0014] The control unit may control a defrosting operation based on
the amount of frost.
[0015] The control unit may determine an amount of frost remaining
on the refrigerant pipe based on the difference of wave forms in
the defrosting operation, and determine whether or not the
defrosting operation is terminated based on the amount of the
remaining frost.
[0016] In accordance with another aspect, the present invention
provides a cooling system including a plurality of oscillatory wave
generating units installed on a refrigerant pipe and generating
oscillatory waves; a plurality of oscillatory wave sensing units
installed on the refrigerant pipe corresponding to the plurality of
oscillatory wave generating units and sensing the oscillatory
waves; and a control unit determining amounts of frost formed in
sections of the refrigerant pipe based on differences of wave forms
between the oscillatory waves generated from the oscillatory wave
generating units and the oscillatory waves sensed by the
oscillatory wave sensing units.
[0017] The plurality of oscillatory wave generating units may
sequentially generate the oscillatory waves.
[0018] The refrigerant pipe may be divided into plural sections;
and the plurality of oscillatory wave generating units may be
respectively installed at ends of the sections and the plurality of
oscillatory wave sensing units is respectively installed at the
other ends of the sections.
[0019] The differences of wave forms may be phase differences
between the oscillatory waves generated from the plurality of
oscillatory wave generating units and the oscillatory waves sensed
by the plurality of oscillatory wave sensing units.
[0020] The differences of wave forms may be amplitude differences
between the oscillatory waves generated from the plurality of
oscillatory wave generating units and the oscillatory waves sensed
by the plurality of oscillatory wave sensing units.
[0021] The control unit may control a defrosting operation based on
the amounts of the frost in respective sections.
[0022] The control unit may determine amounts of frost remaining in
the sections of the refrigerant pipe in the defrosting operation,
and determine whether or not the defrosting operation is completed
based on the amounts of the remaining frost.
[0023] The control unit may perform the defrosting operation when
the amount of frost in at least one section of the sections is more
than a reference amount.
[0024] In accordance with a further aspect, the present invention
provides a method of controlling a cooling system, including
generating an oscillatory wave by operating an oscillatory wave
generating unit installed at one end of a refrigerant pipe; sensing
the oscillatory wave by an oscillatory wave sensing unit installed
at the other end of the refrigerant pipe; and determining an amount
of frost formed on the refrigerant pipe based on a difference of
wave forms between the generated oscillatory wave and the sensed
oscillatory wave.
[0025] The determination of the amount of frost may include
calculating a phase difference between the generated oscillatory
wave and the sensed oscillatory wave.
[0026] The determination of the amount of frost may include
calculating an amplitude difference between the generated
oscillatory wave and the sensed oscillatory wave.
[0027] The method may further include determining whether or not it
is a defrosting time point based on the amount of the frost formed
on the refrigerant pipe.
[0028] The method may further include performing a defrosting
operation, when it is determined that it is the defrosting time
point; determining an amount of frost remaining on the refrigerant
pipe by generating an oscillatory wave and sensing the oscillatory
wave; and determining whether or not it is a defrosting operation
ending time point based on the amount of the remaining frost.
[0029] In accordance with a still further aspect, the present
invention provides a method of controlling a cooling system
including generating oscillatory waves by operating a plurality of
oscillatory wave generating units; sensing the oscillatory waves by
a plurality of oscillatory wave sensing units corresponding to the
plurality of oscillatory wave generating units; and determining
amounts of frost formed in sections of a refrigerant pipe based on
differences of wave forms between the generated oscillatory waves
and the sensed oscillatory waves.
[0030] The generation of the oscillatory waves may include
sequentially operating the plurality of oscillatory wave generating
units.
[0031] The sensing of the oscillatory waves may include dividing
the refrigerant pipe into plural sections; and respectively sensing
the oscillatory waves in the sections of the refrigerant pipe.
[0032] The determination of the amounts of frost may include
calculating phase differences between the generated oscillatory
waves and the sensed oscillatory waves.
[0033] The determination of the amounts of frost may include
calculating amplitude differences between the generated oscillatory
waves and the sensed oscillatory waves.
[0034] The method may further include determining whether or not it
is a defrosting time point based on the amounts of frost formed in
the sections of the refrigerant pipe.
[0035] The method may further include performing a defrosting
operation, when it is determined that it is the defrosting time
point; determining amounts of frost remaining in the sections of
the refrigerant pipe by generating oscillatory waves and sensing
the oscillatory waves; and determining whether or not it is a
defrosting operation ending time point based on the amounts of the
remaining frost.
[0036] The method may further include respectively comparing the
amounts of frost in the sections with a reference amount; and
performing the defrosting operation, when the amount of frost in at
least one section of the sections is more than the reference
amount.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments, taken in conjunction with
the accompanying drawings in which:
[0038] FIG. 1 is an exemplary view of a cooling system in
accordance with an embodiment;
[0039] FIG. 2 is a detailed exemplary view of a cooling system in
accordance with one embodiment;
[0040] FIG. 3 is a control diagram of the cooling system in
accordance with one embodiment;
[0041] FIG. 4, parts (a) and (b), and FIG. 5, parts (a) and (b),
are graphs illustrating wave forms of the cooling system in
accordance with one embodiment;
[0042] FIG. 6 is a flow chart illustrating a method of controlling
the cooling system in accordance with one embodiment;
[0043] FIG. 7 is a detailed exemplary view of a cooling system in
accordance with another embodiment;
[0044] FIG. 8 is a control diagram of the cooling system in
accordance with another embodiment; and
[0045] FIG. 9 is a flow chart illustrating a method of controlling
the cooling system in accordance with another embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0046] Reference will now be made in detail to the embodiments of
the present invention, an example of which is illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout. The embodiments are described below to
explain the present invention by referring to the annexed
drawings.
[0047] In these embodiments, among cooling systems using a
refrigerating cycle, a refrigerator will be exemplarily
described.
[0048] As shown in FIG. 1, the refrigerator includes a main body 10
provided with an opened front surface, and a storage chamber 20
provided in the main body 10 to store foods. The storage chamber 20
is horizontally divided into a freezing chamber and a cooling
chamber side by side by an intermediate diaphragm. The front
surfaces of the freezing chamber and the cooling chamber are
opened, and doors 30 to shield the freezing chamber and the cooling
chamber from the outside are respectively provided at the opened
front surfaces of the freezing chamber and the cooling chamber.
Further, a duct 40, through which air flows, is formed between the
main body 10 and the wall of the storage chamber 20, and a
plurality of holes, through which air in the storage chamber and
the duct 40 is circulated into each other, is formed through the
wall of the storage chamber 20.
[0049] An evaporator 50 to cool surrounding air through a cooling
effect that surrounding latent heat is absorbed by evaporating a
refrigerant supplied from a condenser (not shown), a fan 60 to
absorb air in the storage chamber 20 and transmit the air passed
through the evaporator 50 to the storage chamber 20, and a heating
unit 70 to remove frost formed on the evaporator 50 are installed
in the duct 40. Further, a compressor 80 to compress the
refrigerant and transmit the compressed refrigerant to the
condenser (not shown), and the condenser (not shown) to condense
the refrigerant in a high-temperature and high-pressure state
compressed by the compressor 80 through the radiation of heat are
installed in a machinery chamber provided in the lower portion of
the inside of the main body 10.
[0050] The evaporator 50 includes a refrigerant pipe 51, in which
the refrigerant flows, and a plurality of refrigerant pins (not
shown) mounted on the refrigerant pipe 51 to increase a
heat-exchanging efficiency. The evaporator 50 evaporates the
refrigerant in a low-temperature and low-pressure state at a low
temperature and a low pressure and exchanges heat with air having a
relatively higher temperature in the refrigerator, and thus serves
to lower the temperature in the refrigerator, and frost is
continuously formed on the refrigerant pipe 51 and the refrigerant
pins due to a temperature difference. Therefore, a defrosting
operation to remove the frost formed on the evaporator 50 is
indispensably performed. In order to perform the defrosting
operation, an amount of frost formed on the evaporator 50 needs to
be detected.
[0051] Thereby, in order to detect the amount of the front formed
on the refrigerant pipe 51, an oscillatory wave generating unit 91
and an oscillatory wave sensing unit 92 are installed on the
refrigerant pipe 51 of the evaporator 50. The oscillatory wave
generating unit 91 and the oscillatory wave sensing unit 92 will be
described with reference to FIG. 2.
[0052] The oscillatory wave generating unit 91 is installed at one
end of the refrigerant pipe 51 and generates an oscillatory wave,
and the oscillatory wave sensing unit 92 is installed at the other
end of the refrigerant pipe 51 and senses the oscillatory wave of
the refrigerant pipe 51. That is, when it is supposed that the
refrigerant flows from one end of the refrigerant pipe 51 to the
other end of the refrigerant pipe 51, one of the oscillatory wave
generating unit 91 and the oscillatory wave sensing unit 92 is
installed at one end of the refrigerant pipe 51 and the other one
of the oscillatory wave generating unit 91 and the oscillatory wave
sensing unit 92 is installed at the other end of the refrigerant
pipe 51.
[0053] A piezoelectric element or a small-sized motor, which can
generate an oscillatory wave, is used as an actuator of the
oscillatory wave generating unit 91. Further, actuators of various
kinds, which can generate an oscillation, may be used as the
actuator of the oscillatory wave generating unit 91.
[0054] A piezoelectric element or an acceleration sensor, which can
sense the oscillatory wave flowing along the refrigerant pipe 51,
convert the sensed oscillatory wave into a voltage, and output a
wave form corresponding to the voltage, is used as a sensor of the
oscillatory wave sensing unit 92. Further, sensors of various
kinds, which can convert an oscillatory wave into a voltage, may be
used as the sensor of the oscillatory wave sensing unit 92.
[0055] That is, the oscillatory wave generating unit 91 transmits
an oscillatory wave corresponding to a reference wave form having
regular frequency and amplitude, which are predetermined, to the
refrigerant pipe 51 according to the instructions of a control unit
100, and the oscillatory wave sensing unit 92 senses the
oscillatory wave flowing along the refrigerant pipe 51, converts
the sensed oscillatory wave into a voltage, and outputs the wave
form of the voltage to the control unit 100.
[0056] Here, the control unit 100 controls the cooling of the fan
60, the heating unit 70, and the compressor 80 and the defrosting
operation according to the wave form of the oscillatory wave
transmitted from the oscillatory wave sensing unit 92. This control
will be described with reference to FIG. 3.
[0057] FIG. 3 is a control diagram of the cooling system in
accordance with one embodiment. The cooling system includes the
oscillatory wave generating unit 91, the oscillatory wave sensing
unit 92, the control unit 100, a storing unit 110, a fan driving
unit 120, a heating unit driving unit 130, and a compressor driving
unit 140.
[0058] The oscillatory wave generating unit 91 generates an
oscillatory wave corresponding to the reference wave form having
regular frequency and amplitude, which are predetermined, at a set
time according to the instructions of the control unit 100, and
transmits the oscillatory wave to the refrigerant pipe 51.
[0059] The oscillatory wave sensing unit 92 senses the oscillatory
wave flowing along the refrigerant pipe 51, converts the sensed
oscillatory wave into a voltage, and outputs the wave form (sensed
wave form) of the voltage to the control unit 100.
[0060] Frost formed on the evaporator 50 becomes a resistance
factor to the flow of the oscillatory wave along the refrigerant
pipe 51, and changes the wave form of the oscillatory wave. That
is, the change degree of the reference wave form corresponding to
the oscillatory wave is varied according to the amount of the front
formed on the evaporator 50. This change of the reference wave form
will be described with reference to FIG. 4, parts (a) and (b), and
FIG. 5, parts (a) and (b).
[0061] FIG. 4, parts (a) and (b), respectively illustrate a
reference wave form and a sensed wave form of an oscillatory wave,
in case that the amount of the frost formed on the evaporator 50 is
small, and FIG. 5, parts (a) and (b), respectively illustrate a
reference wave form and a sensed wave form of an oscillatory wave,
in case that the amount of the frost formed on the evaporator 50 is
large. By comparison, a phase difference (T1) between the reference
wave form of FIG. 4, part (a), and the sensed wave form of FIG. 4,
part (b), is smaller than a phase difference (T2) between the
reference wave form of FIG. 5, part (a), and the sensed wave form
of FIG. 5, part (b), and an amplitude difference between the
reference wave form of FIG. 4, part (a), and the sensed wave form
of FIG. 4, part (b), is smaller than an amplitude difference
between the reference wave form of FIG. 5, part (a), and the sensed
wave form of FIG. 5, part (b). As described above, it is
appreciated that the oscillatory wave generated when the amount of
the frost formed on the evaporator 50 is large has a large phase
difference between the reference wave form and the sensed wave
form, a larger amplitude between the reference wave form and the
sensed wave form, and a more distorted shape of the sensed wave
form, compared with the oscillatory wave generated when the amount
of the frost formed on the evaporator 50 is small.
[0062] That is, as the amount of the frost formed on the evaporator
50 is increased, resisting force to the oscillatory wave is
increased, and a difference between an oscillatory wave generating
time and an oscillatory wave sensing time is increased and thus a
phase difference is increased. Further, an amplitude difference
between the reference wave form of the generated oscillatory wave
and the sensed wave form of the sensed oscillatory wave is
increased, and a distorted degree of the sensed oscillatory wave is
increased.
[0063] The control unit 100 transmits the reference wave regular
frequency and regular amplitude, which are predetermined, to the
oscillatory wave generating unit 91 at a set time, determines the
amount of the frost formed on the evaporator 50 by comparing the
sensed wave form with the reference wave, when the sensed wave form
is inputted from the oscillatory wave sensing unit 92 to the
control unit 100, and performs a defrosting operation at the
optimum defrosting time point according to a result of the
determination.
[0064] Here, the control unit 100 measures the amount of the frost
formed on the refrigerant pipe 51 of the evaporator 50 based on at
least one of the phase difference and the amplitude difference
between the reference wave form of the oscillatory wave generated
from the oscillatory wave generating unit 91 and the sensed wave
form of the oscillatory wave sensed by the oscillatory wave sensing
unit 92.
[0065] To be more particular, in case that the control unit 100
determines the amount of frost using the phase difference between
the wave forms, the control unit 100 calculates the phase
difference by comparing the phase of the sensed wave form of the
oscillatory wave with the phase of the reference wave form of the
oscillatory wave, and determines the amount of frost by comparing
the calculated phase difference with a phase difference data stored
in the storing unit 110.
[0066] In case that the control unit 100 determines the amount of
frost using the amplitude difference between the wave forms, the
control unit 100 calculates the amplitude difference by comparing
the amplitude of the sensed wave form of the oscillatory wave with
the amplitude of the reference wave form of the oscillatory wave,
and determines the amount of frost by comparing the calculated
amplitude difference with an amplitude difference data stored in
the storing unit 110.
[0067] In case that the control unit 100 determines the amount of
frost using the phase difference and the amplitude difference
between the wave forms, the control unit 100 calculates the phase
difference by comparing the phase of the sensed wave form of the
oscillatory wave with the phase of the reference wave form of the
oscillatory wave, calculates the amplitude difference by comparing
the amplitude of the sensed wave form of the oscillatory wave with
the amplitude of the reference wave form of the oscillatory wave,
and determines the amount of frost by matching the calculated phase
difference and the calculated amplitude difference with each other
and comparing the obtained matching value with a phase difference
and amplitude difference matching data stored in the storing unit
110.
[0068] Further, the control unit 100 determines whether or not it
is a defrosting time point by comparing the determined amount of
frost with a reference amount of frost, and operates of the heating
unit 70 to perform a defrosting operation, when it is determined
that it is a defrosting time point.
[0069] The control unit 100 determines whether or not a defrosting
operation executing time reaches a predetermined reference time,
and stops the heating unit 70, when it is determined that the
defrosting operation executing time reaches the predetermined
reference time.
[0070] Otherwise, the control unit 100 determines the amount of
frost remaining on the refrigerant pipe 51 of the evaporator 50 by
controlling the operation of a frost amount measuring unit 90
during the defrosting operation, and determines whether or not the
operation of the heating unit 70 is stopped by determining whether
or not it is a defrosting operation ending time point according to
a result of the determination. Here, a method of determining the
amount of frost remaining on the refrigerant pipe 51 by controlling
the operation of the frost amount measuring unit 90 is equal to a
method of determining the amount of the frost formed on the
refrigerant pipe 51 by controlling the operation of the frost
amount measuring unit 90.
[0071] As described above, the defrosting operation is performed at
a proper point of time and is stopped at a proper point of time,
and thus power consumed by the defrosting operation is cut
down.
[0072] The storing unit 110 stores a frost amount data
corresponding to the phase difference data between the reference
wave form and the sensed wave form of the oscillatory wave, and a
frost amount data corresponding to the amplitude difference data
between the reference wave form and the sensed wave form of the
oscillatory wave. The storing unit 110 further stores a frost
amount data corresponding to the phase difference and amplitude
difference matching data. The storing unit 110 further stores a
reference amount of frost.
[0073] The fan driving unit 120 rotates the fan 60 at a
predetermined speed according to the operation mode of the
refrigerator, the heating unit driving unit 130 operates the
heating unit 70 according to the instructions of the control unit
100, when the amount of the frost formed on the evaporator 50
reaches the predetermined reference amount of frost, and stops the
operation of the heating unit 70 according to the instructions of
the control unit 100, the compressor driving unit 140 turns on/off
the compressor 80 based on the operation mode of the refrigerator
to maintain the inside of the storage chamber at a designated set
temperature corresponding to the operation mode, and stops the
compression of the refrigerant by the compressor 80 according to
the instructions of the control unit 100 in the defrosting
operation. This method of controlling the cooling system will be
described with reference to FIG. 6.
[0074] FIG. 6 is a flow chart illustrating a method of controlling
the cooling system in accordance with one embodiment of the present
invention.
[0075] The compressor 80 is turned on/off according to the
refrigerating cycle corresponding to an operation mode selected by
a user, and the rotation of the fan 60 is controlled and thus the
inside of the storage chamber is maintained at the designated
temperature. Then, the operation of the frost amount measuring unit
90 is periodically controlled, and thus the amount of the frost
formed on the refrigerant pipe 51 of the evaporator 50 is
determined.
[0076] To be more particular, the oscillatory wave generating unit
91 of the frost amount measuring unit 90 is operated and generates
an oscillatory wave corresponding to the reference wave form having
predetermined regular frequency and regular amplitude (operation
301), and transmits the oscillatory wave to the refrigerant pipe
51. Then, the oscillatory wave flows along the refrigerant pipe 51,
and the oscillatory wave sensing unit 92 of the frost amount
measuring unit 90 senses the oscillatory wave (operation 302). The
oscillatory wave sensing unit 92 converts the sensed oscillatory
wave into a voltage, and outputs the wave form of the voltage.
[0077] When the oscillatory wave flows along the refrigerant pipe
51, the shape of the oscillatory wave is changed, i.e., the sensed
wave form is decreased in amplitude and is distorted, by the frost
formed on the refrigerant pipe 51. That is, the reference wave form
and the sensed wave form of the oscillatory wave become different.
Further, a time (a phase) taken to sense the oscillatory wave,
generated from the oscillatory wave generating unit 91, by the
oscillatory wave sensing unit 92 is varied according to the amount
of the frost formed on the refrigerant pipe 51.
[0078] The control unit 100 compares the sensed wave form of the
oscillatory wave sensed by the oscillatory wave sensing unit 92
with the reference wave form of the oscillatory wave generated from
the oscillatory wave generating unit 91 (operation 303), and thus
determines the amount of the frost formed on the refrigerant pipe
51 of the evaporator 50 (operation 304). That is, the control unit
100 determines the amount of the frost formed on the refrigerant
pipe 51 of the evaporator 50 based on at least one of a phase
difference and an amplitude phase between the reference wave form
and the sensed wave form of the oscillatory wave.
[0079] To be more particular, first, in a case where the control
unit 100 determines the amount of the frost using the phase
difference between the wave forms, the control unit 100 calculates
the phase difference by comparing the phase of the sensed wave form
of the oscillatory wave with the phase of the reference wave form
of the oscillatory wave, and determines the amount of the frost by
comparing the calculated phase difference with the phase difference
data stored in the storing unit 110.
[0080] Secondly, in a case where the control unit 100 determines
the amount of the frost using the amplitude difference between the
wave forms, the control unit 100 calculates the amplitude
difference by comparing the amplitude of the sensed wave form of
the oscillatory wave with the amplitude of the reference wave form
of the oscillatory wave, and determines the amount of the frost by
comparing the calculated amplitude difference with the amplitude
difference data stored in the storing unit 110.
[0081] Thirdly, in a case where the control unit 100 determines the
amount of the frost using the phase difference and the amplitude
difference between the wave forms, the control unit 100 calculates
the phase difference by comparing the phase of the sensed wave form
of the oscillatory wave with the phase of the reference wave form
of the oscillatory wave, calculates the amplitude difference by
comparing the amplitude of the sensed wave form of the oscillatory
wave with the amplitude of the reference wave form of the
oscillatory wave, and determines the amount of the frost by
matching the calculated phase difference and the calculated
amplitude difference with each other and comparing the obtained
matching value with the phase difference and amplitude difference
matching data stored in the storing unit 110.
[0082] The control unit 100 determines whether or not it is a
defrosting operation time point by comparing the amount of the
frost determined by the above method with the reference amount of
frost (operation 305). That is, when the amount of the frost formed
on the refrigerant pipe 51 is more than the reference amount of
frost, the control unit 100 determines that it is the defrosting
operation time point, and operates the heating unit 70 to perform
the defrosting operation (operation 306).
[0083] Further, the control unit 100 determines whether of not the
defrosting operation executing time reaches a predetermined
reference time by counting the defrosting operation executing time,
and stops the operation of the heating unit 70, when it is
determined that the defrosting operation executing time reaches the
reference time.
[0084] Otherwise, the control unit 100 determines the amount of
frost remaining on the refrigerant pipe 51 of the evaporator 50 by
controlling the operations of the oscillatory wave generating unit
91 and the oscillatory wave sensing unit 92 in the defrosting
operation, and determines whether or not the operation of the
heating unit 70 is stopped according to a result of the
determination. Here, the method of determining the amount of frost
remaining on the refrigerant pipe 51 by controlling the operations
of the oscillatory wave generating unit 91 and the oscillatory wave
sensing unit 92 is equal to the method of determining the amount of
the frost formed on the refrigerant pipe 51 by controlling the
operations of the oscillatory wave generating unit 91 and the
oscillatory wave sensing unit 92.
[0085] The defrosting operation is performed at a proper point of
time and is stopped at a proper point of time, as described above,
and thus power consumed by the defrosting operation is cut
down.
[0086] FIG. 7 is a detailed exemplary view of a cooling system in
accordance with another embodiment, and FIG. 8 is a control diagram
of the cooling system in accordance with another embodiment.
[0087] As a refrigerant flows along a refrigerant pipe 51, the
refrigerant is varied in pressure and temperature and thus the
amounts of frost formed on respective sections of the refrigerant
pipe 51 are varied. Therefore, in order to measure the amounts of
frost formed in the respective sections of the refrigerant pipe 51,
the refrigerant pipe 51 of the evaporator 50 is divided into a
plurality of sections, and frost amount measuring units 90 are
respectively installed at the sections to measures the amounts of
frost formed in the respective sections of the refrigerant pipe
51.
[0088] That is, an oscillatory wave generating unit 93 and an
oscillatory wave sensing unit 94 in a pair are installed in each of
the plural sections of the refrigerant pipe 51. As shown in FIG. 7,
one of the oscillatory wave generating units 93 and the oscillatory
wave sensing units 94 is installed at one end of each of the
sections of the refrigerant pipe 51, and the other one of the
oscillatory wave generating units 93 and the oscillatory wave
sensing units 94 is installed at the other end of each of the
sections of the refrigerant pipe 51.
[0089] The plural oscillatory wave generating units 93 sequentially
transmits oscillatory waves corresponding to a reference wave form
having regular frequency and amplitude, which are predetermined, to
the refrigerant pipe 51 according to the instructions of a control
unit 200, and the plural oscillatory wave sensing units 94 senses
the oscillatory waves flowing along the corresponding sections of
the refrigerant pipe 51, convert the sensed oscillatory waves into
voltages, and output the wave forms (sensed wave forms) of the
voltages to the control unit 200.
[0090] Here, the control unit 200 controls the cooling of the fan
60, the heating unit 70, and the compressor 80 and the defrosting
operation according to changes in the wave forms of the oscillatory
waves transmitted from the plural oscillatory wave sensing units
94. This control will be described with reference to FIG. 8.
[0091] FIG. 8 is a control diagram of the cooling system in
accordance with another embodiment. The cooling system includes the
plural oscillatory wave generating unit 93, the plural oscillatory
wave sensing units 94, the control unit 200, a storing unit 210, a
fan driving unit 220, a heating unit driving unit 230, and a
compressor driving unit 240.
[0092] The plural oscillatory wave generating units 93-1 to 93-n
sequentially generate oscillatory waves corresponding to the
reference wave form having regular frequency and amplitude, which
are predetermined, at a set time according to the instructions of
the control unit 200, and transmit the oscillatory waves to the
refrigerant pipe 51. The plural oscillatory wave sensing units 94-1
to 94-n sense the oscillatory waves flowing along the corresponding
sections of the refrigerant pipe 51, convert the sensed oscillatory
waves into voltages, and output the wave forms (sensed wave forms)
of the voltages to the control unit 200.
[0093] At this time, the oscillatory waves generated from the
plurality oscillatory wave generating units 93-1 to 93-n may have
different frequencies, and the oscillatory waves sensed by the
plural oscillatory wave sensing units 94-1 to 94-n may have the
corresponding frequencies of the oscillatory waves generated from
the plurality oscillatory wave generating units 93-1 to 93-n.
Thereby, the plurality oscillatory wave generating units 93-1 to
93-n may generate oscillatory waves at the same point of time.
[0094] When the oscillatory wave generated from one section of the
refrigerant pipe 51 flows along the refrigerant pipe 51, frost
formed in the section of the refrigerant pipe 51 becomes a
resistance factor to the flow of the oscillatory wave, and changes
the wave form of the oscillatory wave. Further, the traveling times
of the oscillatory waves are changed according to the amounts of
the frost in the respective sections of the refrigerant pipe
51.
[0095] The control unit 200 sequentially transmits the reference
wave having predetermined regular frequency and regular amplitude
to the oscillatory wave generating units 93-1 to 93-n of the frost
amount measuring unit 90, and determines the amounts of the frost
formed in the respective sections of the refrigerant pipe 51 based
on the changes of the wave forms of the oscillatory waves in the
respective sections, when the sensed wave forms in the respective
sections are inputted from the oscillatory wave sensing units 94-1
to 94-n to the control unit 200. Here, the control unit 200
measures the amounts of the frost formed in the respective sections
of the refrigerant pipe 51 based on at least one of phase
differences and amplitude differences between the reference wave
forms and the sensed wave forms of the oscillatory waves in the
respective sections.
[0096] To be more particular, first, in a case where the control
unit 200 determines the amounts of the frost using the phase
differences between the wave forms, the control unit 200 calculates
the phase differences by comparing the phases of the sensed wave
forms of the oscillatory waves in the respective sections with the
phase of the reference wave form of the oscillatory wave, and
determines the amounts of the frost in the respective sections by
comparing the calculated phase differences with a phase difference
data stored in the storing unit 210.
[0097] Secondly, in a case where the control unit 200 determines
the amounts of the frost using the amplitude differences between
the wave forms, the control unit 200 calculates the amplitude
differences by comparing the amplitudes of the sensed wave forms of
the oscillatory waves in the respective sections with the amplitude
of the reference wave form of the oscillatory wave, and determines
the amounts of the frost in the respective sections by comparing
the calculated amplitude differences with an amplitude difference
data stored in the storing unit 210.
[0098] Thirdly, in a case where the control unit 200 determines the
amounts of the frost using the phase differences and the amplitude
differences between the wave forms, the control unit 200 calculates
the phase differences by comparing the phases of the sensed wave
forms of the oscillatory waves in the respective sections with the
phase of the reference wave form of the oscillatory wave,
calculates the amplitude differences by comparing the amplitudes of
the sensed wave forms of the oscillatory waves in the respective
sections with the amplitude of the reference wave form of the
oscillatory wave, and determines the amounts of the frost in the
respective sections by matching the calculated phase differences
and the calculated amplitude differences with each other and
comparing the obtained matching values with a phase difference and
the amplitude difference matching data stored in the storing unit
210.
[0099] Further, the control unit 200 determines whether or not it
is a defrosting time point by respectively comparing the determined
amounts of the frost in the sections with a reference amount of
frost, and operates of the heating unit 70 to perform a defrosting
operation, when it is determined that it is a defrosting time
point. Here, in a case where the amount of the frost formed in at
least one section is more than the reference amount of frost, the
control unit 200 determines that it is a defrosting time point.
[0100] The control unit 200 determines whether or not a defrosting
operation executing time reaches a predetermined reference time,
and stops the operation of the heating unit 70, when it is
determined that the defrosting operation executing time reaches the
predetermined reference time.
[0101] Otherwise, the control unit 200 determines the amounts of
the frost remaining in the respective sections of the refrigerant
pipe 51 of the evaporator 50 by controlling the operations of the
oscillatory wave generating units 93 and the oscillatory wave
sensing units 94 during the defrosting operation, and determines
whether or not the operation of the heating unit 70 is stopped by
determining whether or not it is a defrosting operation ending time
point according to a result of the determination. Here, a method of
determining the amounts of the frost remaining in the respective
sections of the refrigerant pipe 51 by controlling the operations
of the oscillatory wave generating units 93 and the oscillatory
wave sensing units 94 is equal to a method of determining the
amounts of the frost formed in the respective sections of the
refrigerant pipe 51 by controlling the operations of the
oscillatory wave generating units 93 and the oscillatory wave
sensing units 94.
[0102] As described above, the defrosting operation is performed at
a proper point of time and is stopped at a proper point of time,
and thus power consumed by the defrosting operation is cut
down.
[0103] The storing unit 210 stores frost amount data corresponding
to the phase difference data between the reference wave forms of
the oscillatory waves generated from the oscillatory wave
generating units 93-1 to 93-n and the sensed wave forms of the
oscillatory waves sensed by the oscillatory wave sensing units 94-1
to 94-n, and frost amount data corresponding to the amplitude
difference data between the reference wave forms of the oscillatory
waves generated from the oscillatory wave generating units 93-1 to
93-n and the sensed wave forms of the oscillatory waves sensed by
the oscillatory wave sensing units 94-1 to 94-n. The storing unit
210 further stores frost amount data corresponding to the phase
difference and the amplitude difference matching data. The storing
unit 210 further stores a reference amount of frost.
[0104] The fan driving unit 220 rotates the fan 60 at a
predetermined speed according to the operation mode of the
refrigerator, the heating unit driving unit 230 operates the
heating unit 70 according to the instructions of the control unit
200, in case that the amounts of the frost formed on the evaporator
50 reach the predetermined reference amount of frost, and stops the
operation of the heating unit 70 according to the instructions of
the control unit 200, the compressor driving unit 240 turns on/off
the compressor 80 based on the operation mode of the refrigerator
to maintain the inside of the storage chamber at a designated set
temperature corresponding to the operation mode, and stops the
compression of the refrigerant by the compressor 80 according to
the instructions of the control unit 200 in the defrosting
operation. This method of controlling the cooling system will be
described with reference to FIG. 9.
[0105] FIG. 9 is a flow chart illustrating a method of controlling
the cooling system in accordance with another embodiment.
[0106] The compressor 80 is turned on/off according to the
refrigerating cycle corresponding to an operation mode selected by
a user, and the rotation of the fan 60 is controlled and thus the
inside of the storage chamber is maintained at the designated
temperature. Then, the operations of the plural frost amount
measuring units 90 are periodically controlled, and thus the frost
amount measuring units 90 respectively determine the amounts of the
frost formed in the sections of the refrigerant pipe 51 of the
evaporator 50.
[0107] To be more particular, the plural oscillatory wave
generating units 93 are sequentially operated and generate
oscillatory waves corresponding to the reference wave form having
predetermined regular frequency and regular amplitude (operation
401), and transmit the oscillatory waves to the refrigerant pipe
51. Then, the oscillatory waves sequentially flow along the
respective sections of the refrigerant pipe 51, and the oscillatory
wave sensing units 94 installed at the corresponding sections sense
the oscillatory waves (operation 402). The plural oscillatory wave
sensing units 94 convert the sensed oscillatory waves into
voltages, and output the wave forms (sensed wave forms) of the
voltages.
[0108] Here, the sensed wave forms in the respective sections of
the refrigerant pipe 51 are varied, i.e., are decreased in
amplitude and distorted, according to the amounts of the frost in
the sections. Further, phase differences between the reference wave
forms of the oscillatory waves generated from the oscillatory wave
generating units 93 and the sensed wave forms of the oscillatory
waves sensed by the oscillatory wave sensing units 94 are varied
according to the amounts of the frost formed in the respective
sections of the refrigerant pipe 51.
[0109] The control unit 200 compares the sensed wave forms of the
oscillatory waves with the reference wave forms of the oscillatory
waves (operation 403), and then determines the amounts of the frost
formed in the respective sections of the refrigerant pipe 51 based
on the changes in the wave forms of the oscillatory waves. That is,
the control unit 200 determines the amounts of the frost formed in
the respective sections of the refrigerant pipe 51 of the
evaporator 50 based on at least one of phase differences and
amplitude phases between the reference wave forms and the sensed
wave forms of the oscillatory waves in the respective sections
(operation 404).
[0110] To be more particular, first, in a case where the control
unit 200 determines the amounts of the frost using the phase
differences between the wave forms, the control unit 200 calculates
the phase differences by comparing the phases of the sensed wave
forms of the oscillatory waves in the respective sections with the
phases of the reference wave forms of the oscillatory waves, and
determines the amounts of the frost in the respective sections by
comparing the calculated phase differences with the phase
difference data stored in the storing unit 210.
[0111] Secondly, in a case where the control unit 200 determines
the amounts of the frost using the amplitude differences between
the wave forms, the control unit 200 calculates the amplitude
differences by comparing the amplitudes of the sensed wave forms of
the oscillatory waves in the respective sections with the
amplitudes of the reference wave forms of the oscillatory waves,
and determines the amounts of the frost in the respective sections
by comparing the calculated amplitude differences with the
amplitude difference data stored in the storing unit 210.
[0112] Thirdly, in a case where the control unit 200 determines the
amounts of the frost using the phase differences and the amplitude
differences between the wave forms, the control unit 200 calculates
the phase differences by comparing the phases of the sensed wave
forms of the oscillatory waves in the respective sections with the
phase of the reference wave forms of the oscillatory waves,
calculates the amplitude differences by comparing the amplitudes of
the sensed wave forms of the oscillatory waves in the respective
sections with the amplitude of the reference wave forms of the
oscillatory waves, and determines the amounts of the frost in the
respective sections by matching the calculated phase differences
and the calculated amplitude differences with each other and
comparing the obtained matching values with the phase difference
and the amplitude difference matching data in the storing unit
210.
[0113] The control unit 200 determines whether or not it is a
defrosting operation time point by comparing the amounts of the
frost formed in the respective sections with the reference amount
of frost (operation 405). That is, when the amount of the frost
formed in at least one section of the refrigerant pipe 51 is more
than the reference amount of frost, the control unit 200 determines
that it is the defrosting operation time point (operation 406), and
operates the heating unit 70 to perform the defrosting operation
(operation 407).
[0114] Further, the control unit 200 determines whether of not a
defrosting operation executing time reaches a predetermined
reference time by counting the defrosting operation executing time,
and stops the operation of the heating unit 70, when it is
determined that the defrosting operation executing time reaches the
reference time.
[0115] Otherwise, the control unit 200 determines the amount of
frost remaining on the refrigerant pipe 51 of the evaporator 50 by
controlling the operation of at least one pair of the oscillatory
wave generating unit 93 and the oscillatory wave sensing unit 94 in
the defrosting operation, and determines whether or not the
operation of the heating unit 70 is stopped according to a result
of the determination. Here, the at least one pair of the
oscillatory wave generating unit 93 and the oscillatory wave
sensing unit 94 is installed in a section, in which it is
determined that the amount of frost formed is larger than the
reference amount of frost.
[0116] The defrosting operation is performed at a proper point of
time and is stopped at a proper point of time, as described above,
and thus power consumed by the defrosting operation is cut
down.
[0117] In accordance with one aspect of the present invention, the
amount of the frost formed on the refrigerant pipe of the
evaporator is sensed by comparing a wave form of an oscillatory
wave generated from one end of the refrigerant and a wave form of
the oscillatory wave sensed by the other one end of the
refrigerant, thus increasing the accuracy in sensing the amount of
the frost formed on the refrigerator.
[0118] In accordance with another aspect of the present invention,
it is possible to prevent the lowering of a heat-exchanging
performance and the excessive consumption of power due to the
formation of frost during a heat-exchanging process of the cooling
system, such as a refrigerator, a Kimchi refrigerator, or an air
conditioner. That is, the amount of the frost formed on the
evaporator is accurately sensed and a proper defrosting operation
starting time point and a proper defrosting operation ending time
point are determined, thereby optimizing the defrosting operation
and thus enhancing a heat-exchanging performance and increasing
energy efficiency.
[0119] In accordance with a further aspect of the present
invention, the amounts of frost formed in sections of the
refrigerant pipe are easily sensed, thereby optimizing the
defrosting operation although the amounts of frost in the
respective sections are different.
[0120] Although embodiments of the invention have been shown and
described, it would be appreciated by those skilled in the art that
changes may be made in these embodiments without departing from the
principles and spirit of the invention, the scope of which is
defined in the claims and their equivalents.
* * * * *