U.S. patent application number 13/672076 was filed with the patent office on 2013-05-09 for refrigerator using non-azeotropic refrigerant mixture and control method thereof.
This patent application is currently assigned to KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION. The applicant listed for this patent is KOREA UNIVERSITY RESEARCH AND BUSINE, SAMUSNG ELECTRONICS CO., LTD.. Invention is credited to Yong Han Kim, Young Chan Kim, Kook-Jeong Seo, Won Jae YOON.
Application Number | 20130111933 13/672076 |
Document ID | / |
Family ID | 47323895 |
Filed Date | 2013-05-09 |
United States Patent
Application |
20130111933 |
Kind Code |
A1 |
YOON; Won Jae ; et
al. |
May 9, 2013 |
REFRIGERATOR USING NON-AZEOTROPIC REFRIGERANT MIXTURE AND CONTROL
METHOD THEREOF
Abstract
A refrigerator using a non-azeotropic refrigerant mixture (NARM)
and a control method thereof. The refrigerator reduces the
rotational speed of a freezing chamber fan or stopping the freezing
chamber fan for a designated time, and/or increasing the rotational
speed of a compressor in a simultaneous freezing/refrigerating
operation mode of an NARM cycle as compared to a freezing operation
mode, and may thus decrease evaporation latent heat of a
refrigerant consumed by a freezing chamber evaporator and
relatively increase evaporation latent heat of the refrigerant
usable in a refrigerating chamber evaporator without increase in a
charging amount of the refrigerant, thereby preventing
over-charging due to increase in the charging amount of the
refrigerant and reducing cycling loss.
Inventors: |
YOON; Won Jae; (Seoul,
KR) ; Kim; Young Chan; (Seoul, KR) ; Kim; Yong
Han; (Cheonan, KR) ; Seo; Kook-Jeong; (Suwon,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMUSNG ELECTRONICS CO., LTD.;
KOREA UNIVERSITY RESEARCH AND BUSINE; |
Suwon
Seoul |
|
KR
KR |
|
|
Assignee: |
KOREA UNIVERSITY RESEARCH AND
BUSINESS FOUNDATION
Seoul
KR
SAMSUNG ELECTRONICS CO., LTD.
Suwon
KR
|
Family ID: |
47323895 |
Appl. No.: |
13/672076 |
Filed: |
November 8, 2012 |
Current U.S.
Class: |
62/89 ; 62/419;
62/441; 62/56 |
Current CPC
Class: |
F25B 2600/112 20130101;
F25D 29/003 20130101; F25D 11/02 20130101; F25B 2600/0253 20130101;
F25B 9/006 20130101; F25D 17/065 20130101; F25D 29/00 20130101 |
Class at
Publication: |
62/89 ; 62/419;
62/441; 62/56 |
International
Class: |
F25D 17/06 20060101
F25D017/06; F25D 29/00 20060101 F25D029/00; F25D 11/02 20060101
F25D011/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 8, 2011 |
KR |
10-2011-0115911 |
Claims
1. A refrigerator comprising: a freezing chamber and a
refrigerating chamber; a compressor to compress a refrigerant; a
refrigerating chamber evaporator to cool the refrigerating chamber;
a freezing chamber evaporator provided at an upstream position as
compared to a position of the refrigerating chamber evaporator, and
to cool the freezing chamber; a freezing chamber fan to blow cool
air having undergone heat exchange in the freezing chamber
evaporator; and a controller to control operations of the
compressor and the freezing chamber fan, wherein the refrigerator
has a freezing operation mode and a simultaneous
freezing/refrigerating operation mode, and wherein the controller
changes a rotational speed of at least one of the freezing chamber
fan and the compressor so as to increase evaporation latent heat of
the refrigerant introduced into the refrigerating chamber
evaporator in the simultaneous freezing/refrigerating operation
mode as compared to the freezing operation mode.
2. The refrigerator according to claim 1, wherein the controller
lowers the rotational speed of the freezing chamber fan in the
simultaneous freezing/refrigerating operation mode as compared to
the freezing operation mode.
3. The refrigerator according to claim 1, wherein the controller
temporarily stops the rotational speed of the freezing chamber fan
in the simultaneous freezing/refrigerating operation mode.
4. The refrigerator according to claim 1, wherein the controller
increases the rotational speed of the compressor in the
simultaneous freezing/refrigerating operation mode as compared to a
freezing operation mode.
5. The refrigerator according to claim 1, wherein the controller
lowers the rotational speed of the freezing chamber fan or
temporarily stops the operation of the freezing chamber fan while
increasing the rotational speed of the compressor in the
simultaneous freezing/refrigerating operation mode as compared to
the freezing operation mode.
6. A control method of a refrigerator in which a freezing chamber
evaporator is provided at an upstream position as compared to a
position of the refrigerating chamber evaporator, and having a
freezing operation mode and a simultaneous freezing/refrigerating
operation mode, comprising: determining whether or not the
refrigerator operates in a simultaneous freezing/refrigerating
operation mode; and changing a rotational speed of at least one of
a freezing chamber fan and a compressor so as to increase
evaporation latent heat of a refrigerant introduced into the
refrigerating chamber evaporator, when the refrigerator operates in
the simultaneous freezing/refrigerating operation mode.
7. The control method according to claim 6, wherein the changing of
the rotational speed of at least one of the freezing chamber fan
and the compressor includes lowering the rotational speed of the
freezing chamber fan in the simultaneous freezing/refrigerating
operation mode as compared to the freezing operation mode.
8. The control method according to claim 6, wherein the changing of
the rotational speed of at least one of the freezing chamber fan
and the compressor includes temporarily stopping the rotational
speed of the freezing chamber fan in the simultaneous
freezing/refrigerating operation mode as compared to the freezing
operation mode.
9. The control method according to claim 6, wherein the changing of
the rotational speed of at least one of the freezing chamber fan
and the compressor includes increasing the rotational speed of the
compressor in the simultaneous freezing/refrigerating operation
mode as compared to the freezing operation mode.
10. The control method according to claim 6, wherein the changing
of the rotational speed of at least one of the freezing chamber fan
and the compressor includes lowering the rotational speed of the
freezing chamber fan or temporarily stopping the operation of the
freezing chamber fan while increasing the rotational speed of the
compressor in the simultaneous freezing/refrigerating operation
mode as compared to the freezing operation mode.
11. The refrigerator according to claim 1, wherein the refrigerant
is a non-azeotropic refrigerant mixture.
12. The control method according to claim 6, wherein the
refrigerant is a non-azeotropic refrigerant mixture.
13. A refrigerator comprising: a compressor to compress a
refrigerant; a refrigerating chamber evaporator to cool the
refrigerating chamber; a freezing chamber evaporator to cool the
freezing chamber, and provided at an upstream position than a
position of the refrigerating chamber evaporator; and a controller
to control an operation of the compressor, wherein the refrigerator
has a freezing operation mode and a simultaneous
freezing/refrigerating operation mode, and the controller changes
the rotational speed of the compressor so as to increase
evaporation latent heat of the refrigerant introduced into the
refrigerating chamber evaporator in the simultaneous
freezing/refrigerating operation mode as compared to the freezing
operation mode.
14. The refrigerator according to claim 13, wherein the controller
increases the rotational speed of the compressor in the
simultaneous freezing/refrigerating operation mode as compared to
the freezing operation mode.
15. The refrigerator according to claim 13, wherein the refrigerant
is a non-azeotropic refrigerant mixture.
16. A control method of a refrigerator in which a freezing chamber
evaporator is provided at an upstream position than a position of
the refrigerating chamber evaporator, and having a freezing
operation mode and a simultaneous freezing/refrigerating operation
mode, comprising: determining whether the refrigerator operates in
a simultaneous freezing/refrigerating operation mode; and changing
the rotational speed of a compressor as compared to the freezing
operation mode so as to increase evaporation latent heat of a
refrigerant introduced into the refrigerating chamber evaporator
when the refrigerator operates in the simultaneous
freezing/refrigerating operation mode.
17. The control method according to claim 16, wherein the changing
of the rotational speed of the compressor includes increasing the
rotational speed of the compressor in the simultaneous
freezing/refrigerating operation mode as compared to the freezing
operation mode.
18. The control method according to claim 16, wherein the
refrigerant is a non-azeotropic refrigerant mixture.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of Korean
Patent Application No. 10-2011-0115911, filed on Nov. 8, 2011 in
the Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present disclosure relate to a
refrigerator using a non-azeotropic refrigerant mixture (NARM) and
a control method thereof.
[0004] 2. Description of the Related Art
[0005] Non-azeotropic refrigerant mixtures (NARMs) are
refrigerants, the temperature of which is changed during a phase
change process differently from pure refrigerants generally used in
refrigerators.
[0006] Efficiency of a refrigerator may be improved by applying
such a non-azeotropic refrigerant to a refrigerant cycle.
[0007] If the non-azeotropic refrigerant is used, a refrigerant
temperature at a point where evaporation is started becomes lower
than the mean evaporation temperature. By applying such a fact to
operation of a freezing chamber, the mean evaporation temperature
may be raised as compared to a pure refrigerant, and thus a
compression ratio may be reduced. For this reason, a refrigerator
using an NARM cycle is configured such that the refrigerant first
passes through a freezing chamber evaporator and then passes
through a refrigerating chamber evaporator differently from a
general refrigerator.
[0008] Therefore, a refrigerant charging amount may be increased
compared to that of a conventional refrigerant cycle and a
refrigerating chamber evaporator may be installed at a position
further upstream than a freezing chamber evaporator.
[0009] In the conventional refrigerant cycle, the refrigerating
chamber evaporator first uses evaporation latent heat of a
refrigerant and then the freezing chamber evaporator uses remaining
latent heat during simultaneous freezing/refrigerating operation.
Here, although evaporation latent heat of the refrigerant usable in
the freezing chamber evaporator is sufficient, freezing chamber
heat load is supplemented in an independent freezing operation mode
and thus operation of the cycle is not hindered.
[0010] However, in case of such a serial NARM cycle, the freezing
chamber evaporator is installed at a position further upstream than
the refrigerating chamber evaporator and thus the refrigerating
chamber evaporator uses evaporation latent heat remaining after use
in the freezing chamber evaporator. Since cooling operation of the
refrigerating chamber needs to be finished in the simultaneous
freezing/refrigerating operation mode (because there is no
independent refrigerating operation mode in the conventional
refrigerant cycle), evaporation latent heat remaining after use in
the freezing chamber evaporator needs to be sufficient to perform
the cooling operation of the refrigerating chamber.
[0011] For this reason, the charging amount of the refrigerant in
the NARM cycle is increased. Increase in the charging amount of the
refrigerant causes overcharge of the refrigerant during independent
freezing operation, thus producing side effects, such as lowering
of system efficiency. Because over-charging of the refrigerant at
an amount more than a proper level causes increase of input of the
compressor and rise of an evaporation temperature due to increase
in the operating pressure of the cycle.
[0012] Further, increase in the charging amount of the refrigerant
serves to increase loss generated by ON/OFF operation of the
refrigerator. Such loss is referred to as cycling loss, and is
generated in a refrigerator system in which the ON/OFF operation of
the refrigerator is continuously performed. However, the cycling
loss tends to increase together with increase in the charging
amount of the refrigerant. The cycling loss may be divided into
migration loss generated due to transfer of a high-pressure
refrigerant distributed at a high-pressure side to a low-pressure
side when a compressor is turned off, and redistribution loss to
reach again a stable cycle operation state by transferring a part
of the refrigerant located at the low-pressure side to the
high-pressure side when the compressor is turned on, and both
losses increase also together with increase in the charging amount
of the refrigerant.
SUMMARY
[0013] Therefore, it is an aspect of the present disclosure to
provide a refrigerator using a non-azeotropic refrigerant mixture
(NARM) which increases evaporation latent heat usable in a
refrigerating chamber evaporator during simultaneous
freezing/refrigerating operation without increase in the charging
amount of a refrigerant in a NARM cycle, and a control method of
the refrigerator.
[0014] Additional aspects of the disclosure 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
disclosure.
[0015] In accordance with an aspect of the present disclosure, a
refrigerator includes a freezing chamber and a refrigerating
chamber, a compressor to compress a refrigerant, a condenser to
cool the refrigerant discharged from the compressor, a
refrigerating chamber evaporator to cool the refrigerating chamber,
a freezing chamber evaporator provided between the condenser and
the refrigerating chamber evaporator at a position further upstream
than the refrigerating chamber evaporator and to cool the freezing
chamber, a freezing chamber fan blowing cool air having undergone
heat exchange in the freezing chamber evaporator, and a controller
to control operation of the compressor and the freezing chamber
fan, wherein the controller changes the rotational speed of at
least one of the freezing chamber fan and the compressor so as to
increase the amount of the refrigerant introduced into the
refrigerating chamber evaporator in a simultaneous
freezing/refrigerating operation mode.
[0016] The controller may lower the rotational speed of the
freezing chamber fan in the simultaneous freezing/refrigerating
operation mode as compared to a freezing operation mode.
[0017] The controller may temporarily lower the rotational speed of
the freezing chamber fan to 0 in the simultaneous
freezing/refrigerating operation mode.
[0018] The controller may increase the rotational speed of the
compressor in the simultaneous freezing/refrigerating operation
mode as compared to a freezing operation mode.
[0019] The controller may lower the rotational speed of the
freezing chamber fan in the simultaneous freezing/refrigerating
operation mode as compared to a freezing operation mode or
temporarily stop the operation of the freezing chamber fan in the
simultaneous freezing/refrigerating operation mode, and may
increase the rotational speed of the compressor in the simultaneous
freezing/refrigerating operation mode as compared to the freezing
operation mode.
[0020] In accordance with another aspect of the present disclosure,
a control method of a refrigerator in which a freezing chamber
evaporator is provided at a position further upstream than the
refrigerating chamber evaporator includes determining whether or
not the refrigerator is in a simultaneous freezing/refrigerating
operation mode, and changing the rotational speed of at least one
of a freezing chamber fan and a compressor so as to increase the
amount of a refrigerant introduced into the refrigerating chamber
evaporator, upon determining that the refrigerator is in the
simultaneous freezing/refrigerating operation mode.
[0021] The change of the rotational speed of at least one of the
freezing chamber fan and the compressor may include lowering the
rotational speed of the freezing chamber fan in the simultaneous
freezing/refrigerating operation mode as compared to a freezing
operation mode.
[0022] The change of the rotational speed of at least one of the
freezing chamber fan and the compressor may include temporarily
lowering the rotational speed of the freezing chamber fan to 0 in
the simultaneous freezing/refrigerating operation mode.
[0023] The change of the rotational speed of at least one of the
freezing chamber fan and the compressor may include increasing the
rotational speed of the compressor in the simultaneous
freezing/refrigerating operation mode as compared to a freezing
operation mode.
[0024] The change of the rotational speed of at least one of the
freezing chamber fan and the compressor may include lowering the
rotational speed of the freezing chamber fan in the simultaneous
freezing/refrigerating operation mode as compared to a freezing
operation mode or temporarily stopping the operation of the
freezing chamber fan in the simultaneous freezing/refrigerating
operation mode, increasing the rotational speed of the compressor
in the simultaneous freezing/refrigerating operation mode as
compared to the freezing operation mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and/or other aspects of the disclosure will become
apparent and more readily appreciated from the following
description of embodiments, taken in conjunction with the
accompanying drawings of which:
[0026] FIG. 1 is a longitudinal-sectional view of a refrigerator in
accordance with an embodiment of the present disclosure;
[0027] FIG. 2 is a circuit diagram illustrating a non-azeotropic
refrigerant mixture (NARM) cycle of the refrigerator in accordance
with an embodiment of the present disclosure;
[0028] FIG. 3 is a control block diagram of the refrigerator in
accordance with an embodiment of the present disclosure;
[0029] FIG. 4 is a timing diagram illustrating rotational speed
change of a freezing chamber fan in a freezing operation mode and a
simultaneous freezing/refrigerating operation mode of the
refrigerator in accordance with an embodiment of the present
disclosure;
[0030] FIG. 5 is a timing diagram illustrating rotational speed
change of a compressor in the freezing operation mode and the
simultaneous freezing/refrigerating operation mode of the
refrigerator in accordance with an embodiment of the present
disclosure;
[0031] FIG. 6 is a flowchart illustrating a control method of a
refrigerator in accordance with an embodiment of the present
disclosure; and
[0032] FIG. 7 is a flowchart illustrating a control method of a
refrigerator in accordance with another embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0033] Reference will now be made in detail to embodiments of the
present disclosure, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to
like components throughout.
[0034] FIG. 1 is a longitudinal-sectional view of a refrigerator in
accordance with an embodiment of the present disclosure.
[0035] As shown in FIG. 1, the refrigerator in accordance with an
embodiment of the present disclosure includes a freezing chamber 12
located above a diaphragm 11 forming a part of a main body 10 and
provided with the opened front surface, a freezing chamber door 13
opening or closing the opened front surface of the freezing chamber
12, a refrigerating chamber 14 located under the diaphragm 11 and
provided with the opened front surface, a refrigerating chamber
door 15 opening or closing the opened front surface of the
refrigerating chamber 14, and a compressor 16 provided at a rear
portion of the lower portion of the main body 10.
[0036] A freezing chamber heat exchange device 30 and 31 and a
refrigerating chamber heat exchange device 40 and 41 performing
heat exchange are provided between the rear surface portions of the
freezing chamber 12 and the refrigerating chamber 14 and the main
body 10, respectively.
[0037] A freezing chamber temperature sensor 17 and a refrigerating
chamber temperature sensor 18 are provided at designated portions
of the walls of the freezing chamber 12 and the refrigerating
chamber 14.
[0038] Shelves 19 and baskets 20 to store food are provided within
the freezing chamber 12 and the refrigerating chamber 14.
[0039] A machinery chamber which is a separate space is provided at
the rear portion of the lower portion of the main body 10, and the
compressor 16 and the condenser 50 are provided within the
machinery chamber.
[0040] The freezing chamber heat exchange device 30 and 31 includes
a freezing chamber evaporator 30 to cool air in the freezing
chamber 12 through heat exchange, and a freezing chamber fan 31
installed above the freezing chamber evaporator 30 and circulating
cool air having passed through the freezing chamber evaporator 30
to the inside of the freezing chamber 12.
[0041] A suction hole 32 through which air in the freezing chamber
12 is sucked by driving of the freezing chamber fan 31 is formed
below the freezing chamber evaporator 30, and a plurality of
discharge holes 33 to uniformly discharge cool air blown by the
freezing chamber fan 31 to the inside of the freezing chamber 12 is
formed on the rear surface of the freezing chamber 12.
[0042] Similar to the freezing chamber heat exchange device 30 and
31, the refrigerating chamber heat exchange device 40 and 41
includes a refrigerating chamber evaporator 40 to cool air in the
refrigerating chamber 14 through heat exchange, and a refrigerating
chamber fan 41 installed above the refrigerating chamber evaporator
40 and circulating cool air having passed through the refrigerating
chamber evaporator 40 to the inside of the refrigerating chamber
14.
[0043] A suction channel 42 to suck air in the refrigerating
chamber 14 by driving of the refrigerating chamber fan 41 is
provided below the refrigerating chamber evaporator 40, and a
plurality of discharge holes 43 to uniformly discharge cool air
blown by the refrigerating chamber fan 41 to the inside of the
refrigerating chamber 14 is formed on the rear surface of the
refrigerating chamber 14.
[0044] FIG. 2 is a view illustrating a non-azeotropic refrigerant
mixture (NARM) cycle of the refrigerator in accordance with an
embodiment of the present disclosure.
[0045] As shown in FIG. 2, the refrigerator having the NARM cycle
includes the compressor 16, a condenser 50, a capillary tube 60,
the freezing chamber evaporator 30 and the refrigerating chamber
evaporator 40, and these components are sequentially connected to
refrigerant flow channels represented by solid lines.
[0046] The capillary tube 60 is an example of an expansion device
which decompresses and expands a refrigerant discharged from the
condenser 50.
[0047] A condenser fan 51 which sucks air at the outside of the
refrigerator into the condenser 50 and then discharges the air to
the outside of the refrigerator so as to rapidly perform heat
exchange with air at the outside of the refrigerator is provided
around the condenser 50.
[0048] A freezing chamber fan 31 which sucks air at the inside of
the freezing chamber 12 into the freezing chamber evaporator 30 and
then discharges the air to the inside of the freezing chamber 12 so
as to rapidly perform heat exchange with air at the inside of the
freezing chamber 12 is provided around the freezing chamber
evaporator 30.
[0049] A refrigerating chamber fan 41 which sucks air at the inside
of the refrigerating chamber 14 into the refrigerating chamber
evaporator 40 and then discharges the air to the inside of the
refrigerating chamber 14 so as to rapidly perform heat exchange
with air at the inside of the refrigerating chamber 14 is provided
around the refrigerating chamber evaporator 40.
[0050] Further, a 3-way valve 70, i.e., a flow channel switch valve
to selectively change the respective refrigerant flow channels, is
provided at an intersection of a refrigerant pipe connecting the
freezing chamber evaporator 30 and the refrigerating chamber
evaporator 40 and a refrigerant pipe connecting the freezing
chamber evaporator and the inlet side of the compressor 16.
[0051] The NARM cycle having the above-described configuration is
performed by circulating a non-azeotropic refrigerant mixture
(NARM) along the components shown by arrows represented by dotted
lines.
[0052] The temperature of the NARM is changed during a phase change
process differently from pure refrigerants generally used in
refrigerators. That is, the temperature of the NARM is raised as
the NARM is evaporated.
[0053] In general, efficiency of a refrigerator cycle increases as
a compression ratio between a high-pressure side and a low-pressure
side is reduced, and such a compression ratio is restricted by the
refrigerant evaporation temperature of a freezing chamber
evaporator. For example, if it is desired to keep the freezing
chamber at a temperature of -20.degree. C., the evaporation
temperature needs to be lower than such a temperature and thus the
temperature of the inside of the freezing chamber acts as a
critical point in decreasing the compression ratio.
[0054] If the NARM is used under this condition, the refrigerant
temperature at a point where evaporation is started is lower than
the mean evaporation temperature, and thus, by applying the NARM to
operation of the freezing chamber, the mean evaporation temperature
may be raised as compared to a pure refrigerant and a compression
ratio may be reduced.
[0055] For this reason, the refrigerator using the NARM cycle is
configured such that the refrigerant first passes through the
freezing chamber evaporator 30 and then passes through the
refrigerating chamber evaporator 40 differently from a general
refrigerator.
[0056] Therefore, in the NARM cycle, the freezing chamber
evaporator 30 is located at a position further upstream than the
refrigerating chamber evaporator 40.
[0057] Now, the flow of the refrigerant in the NARM cycle will be
described. The refrigerant discharged from the compressor 16
reaches the 3-way valve 70 via the condenser 50, the capillary tube
60 and the freezing chamber evaporator 30. The refrigerant pipe at
the 3-way valve 70 is branched so that the refrigerant having
passed through the freezing chamber evaporator 30 is introduced
into the inlet side of the compressor 16 via the refrigerating
chamber evaporator 40 or is introduced directly into the compressor
16 bypassing the refrigerating chamber evaporator 40 according to
switching of the 3-way valve 70.
[0058] That is, according to switching of the 3-way valve 70, a
freezing/refrigerating cycle in the order of the compressor 16, the
condenser 50, the capillary tube 60, the freezing chamber
evaporator 30, the refrigerating chamber evaporator 40 and then the
compressor 16, and a freezing cycle in the order of the compressor
16, the condenser 50, the capillary tube 60, the freezing chamber
evaporator 30 and then the compressor 16 are formed.
[0059] If it is desired to introduce the refrigerant having passed
through the freezing chamber evaporator 30 into the refrigerating
chamber evaporator 40, a refrigerant flow channel A of the 3-way
valve 70 is opened and a refrigerant flow channel B is closed by
turning the 3-way valve 70 on. Further, if it is desired to
introduce the refrigerant having passed through the freezing
chamber evaporator 30 into the compressor 16 bypassing the
refrigerating chamber evaporator 40, the refrigerant flow channel A
of the 3-way valve 70 is closed and the refrigerant flow channel B
is opened by turning the 3-way valve 70 off.
[0060] In the simultaneous freezing/refrigerating operation mode, a
refrigerant in a gas phase compressed into a high-temperature and
high-pressure state by the compressor 16 of the refrigerator is
introduced into the condenser 50. The condenser 50 converts the
refrigerant from the gas phase to a liquid phase by emitting heat
to the outside through heat exchange with air at the outside of the
refrigerator introduced by the condenser fan 51. The refrigerant in
the liquid phase having passed through the condenser 50 is
decompressed via the capillary tube 60, and is then introduced
sequentially into the freezing chamber evaporator 30 and the
refrigerating chamber evaporator 40. The freezing chamber
evaporator 30 converts the refrigerant from the liquid phase to the
gas phase by absorbing heat at the inside of the freezing chamber
through heat exchange with air at the inside of the refrigerator
introduced by the freezing chamber fan 31. Cool air is generated by
such phase conversion of the refrigerant, and the generated cool
air is introduced into the freezing chamber by the freezing chamber
fan 31 and lowers the temperature of the freezing chamber. Further,
the refrigerating chamber evaporator 40 converts the refrigerant
from the liquid phase to the gas phase by absorbing heat at the
inside of the refrigerating chamber through heat exchange between
with air at the inside of the refrigerator introduced by the
refrigerating chamber fan 41. Cool air is generated by such phase
conversion of the refrigerant, and the generated cool air is
introduced into the refrigerating chamber by the refrigerating
chamber fan 41 and lowers the temperature of the refrigerating
chamber. The refrigerant having passed through the refrigerating
chamber evaporator 40 is introduced into the inlet side of the
compressor 16.
[0061] On the other hand, in the freezing operation mode, a
refrigerant in a gas phase compressed into a high-temperature and
high-pressure state by the compressor 16 of the refrigerator is
introduced into the condenser 50. The condenser 50 converts the
refrigerant from the gas phase to a liquid phase by emitting heat
to the outside through heat exchange with air at the outside of the
refrigerator introduced by the condenser fan 51. The refrigerant in
the liquid phase having passed through the condenser 50 is
decompressed via the capillary tube 60, and is then introduced into
the freezing chamber evaporator 30. The freezing chamber evaporator
30 converts the refrigerant from the liquid phase to the gas phase
by absorbing heat at the inside of the freezing chamber through
heat exchange with air at the inside of the refrigerator introduced
by the freezing chamber fan 31. Cool air is generated by such phase
conversion of the refrigerant, and the generated cool air is
introduced into the freezing chamber by the freezing chamber fan 31
and lowers the temperature of the freezing chamber. The refrigerant
having passed through the freezing chamber evaporator 30 is
introduced into the inlet side of the compressor 16.
[0062] The refrigerator having the above-described configuration
includes an operation control device 100 which increases
evaporation latent heat of the refrigerant usable in the
refrigerating chamber evaporator 40 in the simultaneous
freezing/refrigerating operation mode.
[0063] FIG. 3 is a control block diagram of the refrigerator in
accordance with an embodiment of the present disclosure, FIG. 4 is
a timing diagram illustrating rotational speed change of the
freezing chamber fan in the freezing operation mode and the
simultaneous freezing/refrigerating operation mode of the
refrigerator in accordance with an embodiment of the present
disclosure, and FIG. 5 is a timing diagram illustrating rotational
speed change of the compressor in the freezing operation mode and
the simultaneous freezing/refrigerating operation mode of the
refrigerator in accordance with an embodiment of the present
disclosure.
[0064] As shown in FIG. 3, the operation control device 100
includes a controller 110 which stores programs in the simultaneous
freezing/refrigerating operation mode and the freezing operation
mode and thus outputs control signals to the respective components
to cool both the freezing chamber 12 and the refrigerating chamber
14 in the simultaneous freezing/refrigerating operation mode and to
cool the freezing chamber 12 alone in the freezing operation
mode.
[0065] Particularly, the controller 110 reduces evaporation latent
heat of the refrigerant consumed by the freezing chamber evaporator
30 in the simultaneous freezing/refrigerating operation mode and
thus relatively increases evaporation latent heat of the
refrigerant consumed by the refrigerating chamber evaporator 40.
For this purpose, the controller 110 changes the rotational speed
of at least one of the freezing chamber fan 31 and/or the
compressor 16 so as to increase evaporation latent heat of the
refrigerant introduced into the refrigerating chamber evaporator
40.
[0066] As a control method of the freezing chamber fan 31, a method
of reducing the rotational speed of the freezing chamber fan 31 in
the simultaneous freezing/refrigerating operation mode or a method
of stopping the freezing chamber fan 31 for a designated time in
the simultaneous freezing/refrigerating operation mode may be used.
These methods is to relatively increase evaporation latent heat
usable in the refrigerating chamber evaporator 40 by relatively
reducing evaporation latent heat consumed by the freezing chamber
evaporator 30. Therethrough, cooling operation of the refrigerating
chamber may be performed without increasing the amount of the
refrigerant.
[0067] In addition to the control method of the freezing chamber
fan 31, a control method of the rotational speed of an inverter
compressor may be used. In such a method, the rotational speed of
the compressor in the simultaneous freezing/refrigerating operation
is increased as compared to the freezing operation, thereby
exhibiting similar effects to the control method of the freezing
chamber fan 31. If the rotational speed of the compressor 16 in the
simultaneous freezing/refrigerating operation is increased, the
mass flow rate of the refrigerant circulating in the cycle is
increased at the same refrigerant charging amount and thus
evaporation latent heat of the refrigerant of a relatively larger
amount may be used in the refrigerating chamber evaporator 40.
[0068] The freezing chamber temperature sensor 17 to sense the
temperature of the freezing chamber 12 and the refrigerating
chamber temperature sensor 18 to sense the temperature of the
refrigerating chamber 14 are electrically connected to the input
side of the controller 110.
[0069] Further, the compressor 16, the freezing chamber fan 31, the
refrigerating chamber fan 41 and the condenser fan 51 operated by
control signals from the controller 110 are electrically connected
to the output side of the controller 110.
[0070] The controller 110 includes a fan speed control circuit 111
increasing and decreasing the rotational speed of the freezing
chamber fan 31 and a compressor speed control circuit 112
increasing and decreasing the rotational speed of the compressor
16.
[0071] The 3-way valve 70 operated by a control signal from the
controller 110 is electrically connected to the output side of the
controller 110.
[0072] The above-described controller 110 performs one of the
freezing operation mode and the simultaneous freezing/refrigerating
operation mode. The controller 110 opens or closes the respective
refrigerant flow channels A and B through the 3-way valve 70 in the
freezing operation mode or the simultaneous freezing/refrigerating
operation mode, thereby forming a freezing cycle or a
freezing/refrigerating cycle.
[0073] As shown in FIG. 4, the controller 110 rotates the freezing
chamber fan 31 at a reference speed N1 in the freezing operation
mode, and decreases the rotational speed of the freezing chamber
fan 31 to a speed N2 which is lower than the reference speed N1 in
the simultaneous freezing/refrigerating operation mode. Thereby,
evaporation latent heat of the refrigerant consumed by the freezing
chamber evaporator 30 in the simultaneous freezing/refrigerating
mode may be reduced, and thus evaporation latent heat of the
refrigerant usable in the refrigerant chamber evaporator 40 may be
relatively increased.
[0074] Further, the controller 110 operates the freezing chamber
fan 31 for a reference operation time in the freezing operation
mode, and operates the freezing chamber fan 31 for a time shorter
than the reference operation time in the freezing/refrigerating
operation time. That is, the controller 110 forms a temporary
stoppage section where the freezing chamber fan 31 is temporarily
stopped in the simultaneous freezing/refrigerating operation
mode.
[0075] As shown in FIG. 5, the controller 110 rotates the
compressor 16 at a reference speed N1 in the freezing operation
mode, and increases the rotational speed of the compressor 16 to a
speed N2 which is higher than the reference speed N1 in the
simultaneous freezing/refrigerating operation mode. Thereby,
evaporation latent heat of the refrigerant usable in the
refrigerant chamber evaporator 40 in the simultaneous
freezing/refrigerating mode may be relatively increased.
[0076] FIG. 6 is a flowchart illustrating a control method of a
refrigerator in accordance with an embodiment of the present
disclosure.
[0077] With reference to FIG. 6, the controller 110 first senses
the temperature of the freezing chamber 12, and determines whether
or not a freezing operation condition is satisfied by comparing the
sensed temperature with a predetermined temperature (Operation
200).
[0078] As a result of the determination of Operation 200, if it is
determined that the freezing operation condition is satisfied, the
controller 110 turns the compressor 16 on (Operation 202). At this
time, the controller 110 changes the refrigerant flow channel
through the 3-way valve 70 so that the refrigerant having passed
through the freezing chamber evaporator 30 is introduced into the
inlet side of the compressor 16.
[0079] After turning-on of the compressor 16, the controller 110
rotates the freezing chamber fan 31 at a predetermined speed, i.e.,
a reference speed FS_r (Operation 204).
[0080] After rotation of the freezing chamber fan 31, the
controller 110 determines whether or not a freezing operation off
condition is satisfied (Operation 206).
[0081] As a result of the determination of Operation 206, if it is
determined that the freezing operation off condition is satisfied,
the controller 110 turns the compressor 16 off (Operation 208) and
turns the freezing chamber fan 31 off (Operation 210).
[0082] Thereafter, the controller 110 determines whether or not a
simultaneous freezing/refrigerating operation condition is
satisfied (Operation 212).
[0083] As a result of the determination of Operation 212, if it is
determined that the simultaneous freezing/refrigerating operation
condition is satisfied, the controller 110 turns the compressor 16
on (Operation 214). At this time, the controller 110 changes the
refrigerant flow channel through the 3-way valve 70 so that the
refrigerant having passed through the freezing chamber evaporator
30 is introduced into the inlet side of the compressor 16 via the
refrigerating chamber evaporator 40.
[0084] After turning-on of the compressor 16, the controller 110
rotates the freezing chamber fan 31 at a speed FS (FS<FS_r)
which is lower than the predetermined reference speed FS_r
(Operation 216). At this time, the controller 110 operates the
refrigerating chamber fan 41 at a reference speed RS.
[0085] On the other hand, as the result of the determination of
Operation 200, if it is determined that the freezing operation
condition is not satisfied, the controller 110 moves to Operation
212 and then performs subsequent Operations.
[0086] Further, as the result of the determination of Operation
212, if it is determined that the simultaneous
freezing/refrigerating operation condition is not satisfied, the
controller 110 returns to the predetermined routine.
[0087] FIG. 7 is a flowchart illustrating a control method of a
refrigerator in accordance with another embodiment of the present
disclosure.
[0088] With reference to FIG. 7, the controller 110 first senses
the temperature of the freezing chamber 12, and determines whether
or not a freezing operation condition is satisfied by comparing the
sensed temperature with a predetermined temperature (Operation
300).
[0089] As a result of the determination of Operation 300, if it is
determined that the freezing operation condition is satisfied, the
controller 110 rotates the compressor 16 at a predetermined speed,
i.e., a reference speed CS_r (Operation 302). At this time, the
controller 110 changes the refrigerant flow channel through the
3-way valve 70 so that the refrigerant having passed through the
freezing chamber evaporator 30 is introduced into the inlet side of
the compressor 16.
[0090] After rotation of the compressor 16 at the predetermined
reference speed CS_r, the controller 110 rotates the freezing
chamber fan 31 at a predetermined speed, i.e., a reference speed
FS_r (Operation 304).
[0091] After rotation of the freezing chamber fan 31 at the
predetermined reference speed FS_r, the controller 110 determines
whether or not a freezing operation off condition is satisfied
(Operation 306).
[0092] As a result of the determination of Operation 306, if it is
determined that the freezing operation off condition is satisfied,
the controller 110 turns the compressor 16 off (Operation 308) and
turns the freezing chamber fan 31 off (Operation 310).
[0093] Thereafter, the controller 110 determines whether or not a
simultaneous freezing/refrigerating operation condition is
satisfied (Operation 312).
[0094] As a result of the determination of Operation 312, if it is
determined that the simultaneous freezing/refrigerating operation
condition is satisfied, the controller 110 rotates the compressor
16 at a speed CS (CS>CS_r) which is higher than the
predetermined reference speed CS_r (Operation 314). At this time,
the controller 110 changes the refrigerant flow channel through the
3-way valve 70 so that the refrigerant having passed through the
freezing chamber evaporator 30 is introduced into the inlet side of
the compressor 16 via the refrigerating chamber evaporator 40.
[0095] After rotation of the compressor 16 at the speed CS, the
controller 110 rotates the freezing chamber fan 31 at the
predetermined reference speed FS_r or a speed FS (FS<FS_r) which
is lower than the predetermined reference speed FS_r (Operation
316). At this time, the controller 110 operates the refrigerating
chamber fan 41 at a reference speed RS.
[0096] On the other hand, as the result of the determination of
Operation 300, if it is determined that the freezing operation
condition is not satisfied, the controller 110 moves to Operation
312 and then performs subsequent Operations.
[0097] Further, as the result of the determination of Operation
312, if it is determined that the simultaneous
freezing/refrigerating operation condition is not satisfied, the
controller 110 returns to the predetermined routine.
[0098] In order to maximize effects of the NARM, the dryness and
temperature of the refrigerant at the inlet of the evaporator need
to be lowered, and for this purpose, sub-coolers may be mounted.
The sub-coolers lower the dryness of the refrigerant at the inlet
of the freezing chamber evaporator 30 (the outlet of the capillary
tube) through heat exchange between the refrigerant pipe at the
outlet of the condenser 50 and the refrigerant pipe at the outlet
of the refrigerating chamber evaporator 40, and may thus lower the
temperature of the refrigerant at the inlet of the freezing chamber
evaporator 30. The number and positions of the sub-coolers may be
varied according to characteristics of the cycle, and for example,
two sub-coolers may be used.
[0099] A sub-cooler performing heat exchange between the
low-pressure side refrigerant pipe between the freezing chamber
evaporator 30 and the refrigerating chamber evaporator 40 and the
refrigerant pipe of the condenser 50 is referred to as a low
temperature heat exchanger (LTHX), and serves both to lower the
temperature of the refrigerant at the inlet of the freezing chamber
evaporator and to raise a refrigerating chamber evaporation
temperature. Since operation of the refrigerating chamber 14 uses a
part of evaporation latent heat of the refrigerant, the dryness of
which is high, and the refrigerating chamber evaporation
temperature of the NARM becomes higher than that of a pure
refrigerant. This reduces a heat exchange temperature difference
between the refrigerant and air, thus reducing thermodynamic
irreversible loss. Since the irreversible loss is reduced in
inverse proportion to the refrigerant chamber evaporation
temperature, the LTHX may maximize reduction in the irreversible
loss.
[0100] On the other hand, a sub-cooler performing heat exchange
between the outlet of the evaporator and the refrigerant pipe of
the condenser is referred to as a high temperature heat exchanger
(HTHX). Such an HTHX serves to lower the temperature of the
refrigerant at the inlet of the evaporator in the same manner as
the LTHX.
[0101] As is apparent from the above description, a refrigerator in
accordance with an embodiment of the present disclosure reduces the
rotational speed of a freezing chamber fan or stopping the freezing
chamber fan for a designated time, and/or increasing the rotational
speed of a compressor in a simultaneous freezing/refrigerating
operation mode of an NARM cycle as compared to a freezing operation
mode, and may thus decrease evaporation latent heat of a
refrigerant consumed by a freezing chamber evaporator and
relatively increase evaporation latent heat of the refrigerant
usable in a refrigerating chamber evaporator without increase in a
charging amount of the refrigerant, thereby preventing
over-charging due to increase in the charging amount of the
refrigerant and reducing cycling loss.
[0102] Although a few embodiments of the present disclosure 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 disclosure, the
scope of which is defined in the claims and their equivalents. For
example, the technical features of the present disclosure may be
applied to a direct cooling refrigerator such as a KimChi
refrigerator. In this case, the method of controlling the
rotational speed of the compressor as describe above may be
applied.
* * * * *