U.S. patent application number 14/055424 was filed with the patent office on 2014-09-25 for refrigerator.
This patent application is currently assigned to LG ELECTRONICS INC.. The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Yongjoo PARK, Changho SEO, Jaehoon SHIN, Heayoun SUL.
Application Number | 20140284025 14/055424 |
Document ID | / |
Family ID | 49554093 |
Filed Date | 2014-09-25 |
United States Patent
Application |
20140284025 |
Kind Code |
A1 |
SHIN; Jaehoon ; et
al. |
September 25, 2014 |
REFRIGERATOR
Abstract
A refrigerator with a main body including a refrigerating
compartment at a temperature higher than a freezing temperature and
a freezing compartment at a temperature lower than the freezing
temperature, a deep-freezing storage chamber within the main body
at a temperature lower than that of the freezing compartment. The
refrigerator further includes a compressor, a condenser connected
to an outlet-side of the compressor, a first expansion valve
connected to an outlet-side of the condenser, a first evaporator
connected to an outlet-side of the first expansion valve, and a
heater disposed outside the first expansion valve.
Inventors: |
SHIN; Jaehoon; (Seoul,
KR) ; SUL; Heayoun; (Seoul, KR) ; SEO;
Changho; (Seoul, KR) ; PARK; Yongjoo; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
49554093 |
Appl. No.: |
14/055424 |
Filed: |
October 16, 2013 |
Current U.S.
Class: |
165/63 |
Current CPC
Class: |
F25D 11/022 20130101;
F25B 2600/2513 20130101; F25B 2400/01 20130101; F25B 2341/0661
20130101; F25B 29/003 20130101; F25B 41/067 20130101; F25B 2400/073
20130101; F25B 2600/2511 20130101 |
Class at
Publication: |
165/63 |
International
Class: |
F25B 29/00 20060101
F25B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 22, 2013 |
KR |
10-2013-0031036 |
Claims
1. A refrigerator comprising: a main body comprising a
refrigerating compartment maintained at a temperature higher than a
freezing temperature and a freezing compartment maintained at a
temperature lower than the freezing temperature; a deep-freezing
storage chamber disposed within the main body, the deep-freezing
storage chamber being maintained at a temperature lower than that
of the freezing compartment; a compressor compressing a refrigerant
at a high temperature and a high pressure; a condenser connected to
an outlet-side of the compressor to condense the high-temperature
high-pressure refrigerant; a first expansion valve connected to an
outlet-side of the condenser to expand the refrigerant so that the
refrigerant has a low-temperature low-pressure two-phase state; a
first evaporator connected to an outlet-side of the first expansion
valve to change the refrigerant into a low-temperature low-pressure
gas refrigerant; and a heater disposed outside the first expansion
valve, the heater supplying heat into the first expansion valve to
lower an evaporation temperature of the refrigerant to a
temperature lower than that of the freezing compartment.
2. The refrigerator of claim 1, wherein the heater is disposed in
such a manner that the heater contacts an outer circumferential
surface of the first expansion valve.
3. The refrigerator of claim 2, wherein the compressor comprises a
linear compressor.
4. The refrigerator of claim 2, wherein the first evaporator is an
evaporator used for cooling cool air supplied into the
deep-freezing storage chamber.
5. The refrigerator of claim 4, further comprising: at least one
additional evaporator for cooling one or all of the refrigerating
compartment and the freezing compartment; and at least one
additional expansion valve connected to an inlet-side of the at
least one additional evaporator.
6. The refrigerator of claim 5, wherein the first expansion valve
and the at least one additional expansion valve are connected
parallel to each other, and the refrigerator further comprises: a
switching valve disposed the first and the at least one additional
expansion valves are branched to switch a flow direction of the
refrigerant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority benefit of Korean
Patent Application No. 10-2013-0031036 filed on Mar. 22, 2013,
which is herein incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to a refrigerator.
[0003] Refrigerators are home appliances for storing foods at a low
temperature. For example, a refrigerator includes a refrigerating
compartment to store food in a refrigerated state and a freezing
compartment to store food in a frozen state.
[0004] Recently, demand for a refrigerator including a separate
storage chamber for cooling foods within a short time period to an
ultralow temperature has increased. To achieve the above-described
objects, a separate deep-freezing storage chamber is provided
within a freezing compartment. Also, a structure is provided in
which cool air within a vaporizing chamber is independently
supplied into the deep-freezing storage chamber through a cool air
passage connecting the deep-freezing storage chamber to the
vaporizing chamber. In the related art, since the cool air within
the vaporizing chamber is separately supplied into only the
deep-freezing storage chamber, the deep-freezing storage chamber
may have a temperature lower than that of the freezing compartment
without having an influence on the temperatures of the freezing
compartment and the refrigerating compartment.
[0005] Generally, refrigerators use an R-600a isobutene refrigerant
to lower a temperature of an evaporator to a temperature of about
-40.degree. C. to about -42.degree. C. However, the deep-freezing
storage chamber may require a temperature lower than that of the
evaporator, i.e., a temperature of about -50.degree. C. To
accomplish this, it may be insufficient to use only the separate
deep-freezing storage chamber.
[0006] To meet the demand of the deep-freezing cooling as described
above, a suction pipe connecting the evaporator to a compressor may
exchange heat with an expansion valve. Specifically, in the case
where the suction pipe and the expansion valve exchange heat to
reduce an evaporation temperature, the refrigerant passing through
the expansion valve may further decrease in temperature to increase
a heat absorption capacity, thereby increasing a cooling ability.
However, since an evaporation pressure itself is not decreased, it
may be difficult to decrease the evaporation temperature.
[0007] To solve the above-described limitation, an expansion valve
having a smaller diameter may be used. However, in this case,
although the evaporation pressure is decreased, a saturation
achievement rate of the refrigerant may be further reduced when the
evaporator absorbs heat to lower the temperature of the
deep-freezing storage chamber to a set temperature. That is, the
reduction in the saturation achievement rate of the refrigerant
represents the reduction in an amount of refrigerant which is
saturated to generate a gas by passing through the evaporator.
Thus, an amount of liquid refrigerant introduced into a gas/liquid
separator is greater than that of gas refrigerant. As a result, the
possibility to introduce more liquid refrigerant into the
compressor may be further increased. Thus, a condensation pressure
and an evaporation pressure in the whole refrigeration cycle may be
further increased. Furthermore, the introduction of liquid
refrigerant into the compressor may deteriorate performance of the
compressor or damage the compressor.
SUMMARY
[0008] One or more embodiments provide a refrigerator in which a
temperature of a deep-freezing storage chamber is further lowered
than that of a deep-freezing storage chamber according to the
related art to minimize damage of a compressor, and provide a
method for controlling the same.
[0009] In one embodiment, a refrigerator including: a main body
including a refrigerating compartment maintained at a temperature
higher than a freezing temperature and a freezing compartment
maintained at a temperature lower than the freezing temperature; a
deep-freezing storage chamber disposed within the main body, the
deep-freezing storage chamber being maintained at a temperature
lower than that of the freezing compartment; a compressor
compressing a refrigerant at a high temperature and a high
pressure; a condenser connected to an outlet-side of the compressor
to condense the high-temperature high-pressure refrigerant; a first
expansion valve connected to an outlet-side of the condenser to
expand the refrigerant so that the refrigerant has a
low-temperature low-pressure two-phase state; a first evaporator
connected to an outlet-side of the first expansion valve to change
the refrigerant into a low-temperature low-pressure gas
refrigerant; and a heater disposed outside the first expansion
valve, the heater supplying heat into the first expansion valve to
lower an evaporation temperature of the refrigerant to a
temperature lower than that of the freezing compartment.
[0010] The details of one or more embodiments are set forth in the
accompanying drawings and the description below. Other features
will be apparent from the description and drawings, and from the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a view illustrating a refrigeration cycle of a
refrigerator according to one embodiment.
[0012] FIG. 2 is a p-h diagram for comparing the refrigeration
cycle according to one embodiment to a general refrigeration cycle
according to the related art.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0013] In the following detailed description of the preferred
embodiments, reference is made to the accompanying drawings which
show by way of illustration specific preferred embodiments in which
the invention may be practiced. These embodiments are described in
sufficient detail to enable those skilled in the art to practice
the invention, and it is understood that other embodiments may be
utilized. Logical, structural, mechanical, electrical, and chemical
changes may be made without departing from the spirit or scope of
the invention. To avoid detail not necessary to enable those
skilled in the art to practice the invention, the description may
omit certain information known to those skilled in the art. The
following detailed description is, therefore, not to be taken in a
limiting sense, and the scope of the present disclosure is defined
only by the appended claims.
[0014] Hereinafter, a refrigerator and a method for controlling the
refrigerator according to one embodiment will be described in
detail with reference to the accompanying drawings.
[0015] A refrigerator includes: a main body including a
refrigerating compartment maintained at a temperature higher than a
freezing temperature and a freezing compartment maintained at a
temperature lower than the freezing temperature; a deep-freezing
storage chamber disposed within the main body, the deep-freezing
storage chamber being maintained at a temperature lower than that
of the freezing compartment; a compressor compressing a refrigerant
at a high temperature and a high pressure; a condenser connected to
an outlet-side of the compressor to condense the high-temperature
high-pressure refrigerant; a first expansion valve connected to an
outlet-side of the condenser to expand the refrigerant so that the
refrigerant has a low-temperature low-pressure two-phase state; a
first evaporator connected to an outlet-side of the first expansion
valve to change the refrigerant into a low-temperature low-pressure
gas refrigerant; and a heater disposed outside the first expansion
valve, the heater supplying heat into the first expansion valve to
lower an evaporation temperature of the refrigerant to a
temperature lower than that of the freezing compartment.
[0016] The heater may contact an outer circumferential surface of
the first expansion valve.
[0017] The compressor may include a linear compressor.
[0018] The first evaporator may be an evaporator used for cooling
cool air supplied into the deep-freezing storage chamber.
[0019] The refrigerator may further include at least one additional
evaporator for cooling one or all of the refrigerating compartment
and the freezing compartment and at least one additional expansion
valve connected to an inlet-side of the at least one additional
evaporator.
[0020] The first expansion valve and the at least one additional
expansion valve may be connected parallel to each other, and the
refrigerator may further include a switching valve disposed on a
position at which the first and additional expansion valves are
branched to switch a flow direction of the refrigerant.
[0021] FIG. 1 is a view illustrating a refrigeration cycle of a
refrigerator according to one embodiment.
[0022] Referring to FIG. 1, a refrigeration cycle 10 of a
refrigerator according to one embodiment includes a compressor
compressing a refrigerant into a high-temperature high-pressure gas
state; a condenser 12 disposed on an outlet-side of compressor 11
to phase-change the high-temperature high-pressure gas refrigerant
into a high-temperature high-pressure liquid refrigerant; expansion
valves 14 and 15 disposed on an outlet-side of condenser 12 to
expand the high-temperature high-pressure liquid refrigerant cooled
by passing through condenser 12, thereby changing the
high-temperature high-pressure liquid refrigerant into a
low-temperature low-pressure two-phase refrigerant; and evaporators
16 and 17 respectively disposed on outlet-sides of expansion valves
14 and 15 to phase-change the low-temperature low-pressure
two-phase refrigerant which is changed in phase by passing through
expansion valves 14 and 15 into a low-temperature low-pressure
liquid refrigerant.
[0023] Specifically, compressor 11 may include a linear compressor.
Alternatively, compressor 11 may include a fixed speed or inverter
compressor. When compressor 11 includes a linear compressor,
compressor 11 is controlled so that a top dead center operation is
performed in a deep-freezing cooling process.
[0024] Generally, the condenser 12 may be accommodated in a machine
room disposed in a rear side of the refrigerator to release heat to
the ambient air (e.g., indoor air). Also, a switching valve 13
including a three-way valve may be disposed between condenser 12
and the expansion valves 14 and 15. Switching valve 13 is used for
switching a flow direction of the refrigerant in a structure in
which main evaporator 16 is used for cooling the refrigerating
compartment, and the freezing compartment and deep-freezing
evaporator 17 is used for cooling the deep-freezing storage chamber
and are connected to parallel to each other. Here, the three-way
valve or a four-way valve may be used according to the number of
evaporators. For example, when one main evaporator is used, and
thus a cool air passage connecting the refrigerating compartment to
the freezing compartment is switched to independently control a
temperature of each of the storage compartments, the three-way
valve may be used. On the other hand, in a structure in which an
evaporator for the refrigerating compartment, an evaporator for the
freezing compartment, and an evaporator for the deep-freezing
evaporator are separately provided and connected parallel to each
other, the four-way valve may be applied to switch the flow
direction of the refrigerant.
[0025] One exemplary embodiment in which one main evaporator 16 is
used to cool the refrigerating compartment and the freezing
compartment, and a separate deep-freezing evaporator 17 is used for
cooling the deep-freezing storage chamber and is parallely
connected to main evaporator 16 will be described. Thus, main
expansion valve 15 and deep-freezing expansion valve 14 may be
respectively disposed on inlet-sides of the main evaporator 16 and
the deep-freezing evaporator 17, and the expansion valves 15 are
connected parallel to the outlet-side of the switching valve
13.
[0026] A separate heater 18 may be mounted on an outer
circumferential surface of deep-freezing expansion valve 14 to
reduce a temperature of the refrigerant passing through
deep-freezing expansion valve 14 to a temperature lower than that
of the freezing compartment. Heater 18 is operated in an operation
mode for cooling the deep-freezing storage chamber. When the
deep-freezing storage chamber is cooled to a set temperature, the
heater 18 may be stopped in operation.
[0027] Also, a condensation fan (not shown) and an evaporation fan
(not shown) may be respectively mounted outside condenser 12 and
evaporators 16 and 17 to heat-exchange the indoor air with the
refrigerant or air within the storage chamber with the
refrigerant.
[0028] FIG. 2 is a p-h diagram for comparing the refrigeration
cycle according to an embodiment to a general refrigeration cycle
according to a related art.
[0029] Referring to FIG. 2, in the general refrigeration cycle
according to the related art, and compression, condensation,
expansion, and evaporation are performed in an order of points a,
b, c, and d.
[0030] On the other hand, in the refrigeration cycle according to
an embodiment of the present disclosure, i.e., the refrigeration
cycle including heater 18 on the outer circumferential surface of
deep-freezing expansion valve 14, compression, condensation,
expansion, and evaporation are performed in an order of points e,
f, c, and g.
[0031] As shown in the p-h diagram, when heater 18 mounted on
deep-freezing expansion valve 14 is driven, the refrigerant passing
through deep-freezing expansion valve 14 may be dropped to an
evaporation pressure lower than that in the refrigerant cycle
according to the related art. Specifically, since the evaporation
pressure is lowered, the evaporation temperature is lowered. Thus,
since the evaporation temperature is lowered, cool air within the
deep-freezing storage chamber may be lowered in temperature to less
than that of cool air according to the related art.
[0032] The general refrigeration cycle according to the related art
in the p-h diagram of FIG. 2 represents a cycle diagram when any
heat-exchange member is not provided to the expansion valve. In a
case of a structure in which a suction pipe is heat-exchanged with
the expansion valve, heat may be transferred from the refrigerant
passing through the expansion valve to the refrigerant passing
through the suction pipe, an amount of gas refrigerant of the
refrigerant introduced into the compressor may be increased. Then,
the refrigerant passing through the expansion valve may be
decreased in temperature. Thus, an enthalpy line (a c-d line) of
the refrigerant may be further shifted to the left in the p-h
diagram. As a result, an enthalpy valve of the refrigerant at an
inlet of the evaporator may be decreased. That is, an amount of
heat absorbed into the evaporator may be increased to increase
cooling capacity. However, although the heat exchange may be
performed through the suction pipe, since the evaporation pressure
is not changed, it may be difficult to further reduce the
temperature of the cool air within the deep-freezing storage
chamber even though the cooling capacity is increased.
[0033] Also, in a case where the deep-freezing expansion valve has
a diameter less than that of the main expansion valve, a
refrigerant state point (e.g., point d) when the expansion is
completed, i.e., an evaporation pressure at the inlet of the
deep-freezing evaporator may be further decreased, and also, an
enthalpy valve at the deep-freezing evaporator may be increased.
That is, in the p-h diagram, the point d may be shifted down and to
the right. As a result, the refrigerant may be further decreased in
temperature to decrease the temperature of the deep-freezing
storage chamber. However, due to the decrease in the temperature of
the deep-freezing storage chamber, an amount of refrigerant which
is changed in phase from the liquid refrigerant to the gas
refrigerant in the refrigerant passing through the evaporator may
be reduced. That is, if it is assumed that the refrigerant passing
through the evaporator absorbs energy having the same heat from the
indoor air, an amount of refrigerant which is changed in phase from
the liquid refrigerant to the gas refrigerant may be reduced. This
may represent the reduction in a saturation achievement rate of the
refrigerant. As a result, possibility of the introduction of the
liquid refrigerant into the compressor may be further
increased.
[0034] As proposed in one embodiment, when heater 18 is mounted on
the surface of deep-freezing expansion valve 14, outlet point d of
the deep-freezing expansion valve (or the outlet point of the
deep-freezing evaporator) may be moved to point g in an ideal
state. In an actual refrigeration cycle, point g may be located at
a point that is further shifted to the right.
[0035] If it is assumed that the evaporator absorbs the energy
having the same heat, quality of the refrigerant at the inlet of
the compressor, i.e., quality of the refrigerant at an inlet of a
gas/liquid separator may be further increased in the current
embodiment when compared to the case in which the expansion valve
is changed in diameter. This may represent that the saturation
achievement rate of the refrigerant is not reduced. Thus, the
possibility of the introduction of the liquid refrigerant into the
compressor may be significantly decreased.
[0036] As described above, since heater 18 provided in one
embodiment is attached to deep-freezing expansion valve 17, the
evaporation temperature and pressure of the refrigerant passing
through deep-freezing expansion valve 17 may be significantly
reduced when compared to those of a refrigerant in the related art.
Thus, the deep-freezing storage chamber may be cooled to a
temperature significantly lower than that of the freezing
compartment. That is to say, although a refrigerant passing through
the expansion valve to which the heater is not mounted is lowered
to a temperature of about -40.degree. C., the refrigerant passing
through the expansion valve to which the heater is mounted may be
lowered to a temperature of a maximum -50.degree. C.
[0037] According to the method for controlling the refrigerator
including the above-described constitutions, the separate heater
may be provided to the expansion valve connected to the inlet-side
of the evaporator for the deep-freezing storage chamber to further
decrease the evaporator pressure when compared to that in the
related art. Thus, the evaporator may be lowered up to a
temperature of a maximum -50.degree. C. In addition, the
deterioration in the saturation achievement rate of the refrigerant
which occurs when the expansion valve is changed in diameter may
not occur, preventing the compressor from being degraded in
performance or damaged.
[0038] Although embodiments have been described with reference to a
number of illustrative embodiments thereof, it should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art that will fall within the spirit and scope
of the principles of this disclosure. More particularly, variations
and modifications are possible in the component parts and/or
arrangements of the subject combination arrangement within the
scope of the disclosure, the drawings and the appended claims. In
addition to variations and modifications in the component parts
and/or arrangements, alternative uses will also be apparent to
those skilled in the art.
* * * * *