U.S. patent application number 11/831126 was filed with the patent office on 2008-02-07 for air conditioner and controlling method thereof.
This patent application is currently assigned to LG ELECTRONICS INC.. Invention is credited to Deok HUH, Gil Bong LEE, Won Hee LEE.
Application Number | 20080028773 11/831126 |
Document ID | / |
Family ID | 38997405 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080028773 |
Kind Code |
A1 |
LEE; Gil Bong ; et
al. |
February 7, 2008 |
AIR CONDITIONER AND CONTROLLING METHOD THEREOF
Abstract
An air conditioning system includes an indoor heat exchange unit
which exchanges heat with indoor air, and an outdoor heat exchange
unit which exchanges heat with outdoor air. The outdoor heat
exchange unit performs a defrosting operation to remove frost from
the outdoor heat exchange unit while the indoor heat exchange unit
simultaneously performs a heating operation to heat the indoor
air.
Inventors: |
LEE; Gil Bong; (Seoul,
KR) ; LEE; Won Hee; (Seoul, KR) ; HUH;
Deok; (Gyeonggi-do, KR) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
38997405 |
Appl. No.: |
11/831126 |
Filed: |
July 31, 2007 |
Current U.S.
Class: |
62/80 ; 165/240;
62/151 |
Current CPC
Class: |
F25B 2313/02741
20130101; F25B 2400/075 20130101; F25B 47/022 20130101; F25B 13/00
20130101 |
Class at
Publication: |
62/80 ; 165/240;
62/151 |
International
Class: |
F25D 21/06 20060101
F25D021/06; F25B 29/00 20060101 F25B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 3, 2006 |
KR |
10-2006-0073434 |
Claims
1. An air conditioning system, comprising: an indoor heat exchange
unit which exchanges heat with indoor air; and an outdoor heat
exchange unit which exchanges heat with outdoor air, wherein the
outdoor heat exchange unit performs a defrosting operation to
remove frost from the outdoor heat exchange unit while the indoor
heat exchange unit simultaneously performs a heating operation to
heat the indoor air.
2. The air conditioning system according to claim 1, further
comprising: a compressing unit that discharges high temperature
refrigerant; a switching unit connected to a discharge side of the
compressing unit, the outdoor heat exchange unit being connected to
the switching unit; an expansion unit connected to the outdoor heat
exchange unit, the indoor heat exchange unit being connected to the
expansion unit and the switching unit; and a bypass unit that
provides the high temperature refrigerant discharged from the
compressing unit to an intake side of the outdoor heat exchange
unit during the defrosting operation.
3. The air conditioning system according to claim 2, wherein the
bypass unit is connected to a refrigerant pipe between the
compressing unit and the switching unit.
4. The air conditioning system according to claim 2, wherein the
bypass unit is connected to a refrigerant pipe between the
switching unit and the indoor heat exchange unit.
5. The air conditioning system according to claim 4, further
comprising a connecting unit that provides refrigerant from a
discharge side of the expansion unit to a discharge side of the
outdoor heat exchange unit during the defrosting operation.
6. The air conditioning system according to claim 2, wherein an
accumulator comprising a heating unit is disposed at an intake side
of the compressing unit.
7. The air conditioning system according to claim 2, wherein the
compressing unit comprises a plurality of compressors, and the
bypass unit provides refrigerant discharged from at least one of
the compressors to the intake side of the outdoor heat exchange
unit during the defrosting operation.
8. The air conditioning system according to claim 2, further
comprising a refrigerant pipe connecting the compressing unit to
the switching unit, the refrigerant pipe comprising a valve which
is closed during the defrosting operation.
9. The air conditioning system according to claim 2, wherein the
bypass unit comprises a valve and a pressure controller.
10. The air conditioning system according to claim 2, wherein a
heating unit that heats refrigerant is disposed at an intake side
of the compressing unit.
11. An air conditioning system, comprising: a bypass unit that
provides refrigerant discharged from a compressing unit to an
intake side of an outdoor heat exchange unit during a defrosting
operation; and a connecting unit that provides expanded refrigerant
to a discharge side of the outdoor heat exchange unit during the
defrosting operation.
12. The air conditioning system according to claim 11, wherein the
bypass unit is connected to a refrigerant pipe between a switching
unit and an indoor heat exchange unit, and a refrigerant pipe
between an expansion unit and the outdoor heat exchange unit.
13. The air conditioning system according to claim 11, wherein the
connecting unit is connected to a refrigerant pipe between an
expansion unit and the outdoor heat exchange unit, and a
refrigerant pipe between a switching unit and the outdoor heat
exchange unit.
14. The air conditioning system according to claim 11, wherein the
connecting unit is connected to a refrigerant pipe between an
expansion unit and the bypass unit.
15. The air conditioning system according to claim 11, wherein a
heating unit that heats refrigerant is disposed at an intake side
of the compressing unit.
16. A method for controlling an air conditioning system,
comprising: performing heat exchange with indoor air to heat the
indoor air; and simultaneously defrosting an outdoor heat exchange
unit when a defrosting operation is triggered.
17. The method according to claim 16, wherein defrosting the
outdoor heat exchange unit comprises discharging refrigerant from a
compressing unit, and providing a portion of the discharged
refrigerant to an intake side of the outdoor heat exchange unit via
a bypass unit.
18. The method according to claim 17, further comprising heating
refrigerant introduced to the compressing unit.
19. The method according to claim 16, wherein the defrosting
operation is triggered when the temperature of the outdoor heat
exchange unit is less than a predetermined temperature.
20. The method according to claim 16, wherein an indoor heat
exchange unit performs the heat exchange with the indoor air, and
refrigerant discharged from the indoor heat exchange unit is
provided to a discharge side of the outdoor heat exchange unit via
a connecting unit.
21. The method according to claim 20, wherein refrigerant
discharged from the indoor heat exchange unit is prevented from
flowing into an intake side of the outdoor heat exchange unit.
Description
[0001] This application claims the benefit of Korean Application
No. 10-2006-0073434, filed on Aug. 3, 2006, which is hereby
incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to an air conditioning system
and a controlling method thereof.
[0003] Generally, an air conditioning system is an apparatus for
heating/cooling an indoor space using a refrigerant cycle.
[0004] The air conditioning system provides high temperature
refrigerant compressed by a compressing unit to an indoor heat
exchanger to heat an indoor space. Refrigerant condensed at the
indoor heat exchanger expands and then is provided to an outdoor
heat exchange unit. Refrigerant evaporated at the outdoor heat
exchange unit flows into a compressing unit. At this point, when
outdoor temperature is low, humidity contained in air is frozen on
the surface of the outdoor heat exchange unit. When a large amount
of frost is generated on the surface of the outdoor heat exchange
unit, the heat exchange performance of the outdoor heat exchange
unit is considerably reduced, and efficiency of a refrigerant cycle
is considerably reduced on the whole. Therefore, a defrosting
operation is performed to remove frost generated on the outdoor
heat exchange unit. During the defrosting operation, refrigerant
circulates in an opposite direction to the direction of a heating
operation.
[0005] However, since the air conditioning system circulates
refrigerant in an opposite direction to a direction of the heating
operation during the defrosting operation, the air conditioning
system has not been able to heat an indoor space during the
defrosting operation. Also, since cooling air is supplied to the
indoor space during the defrosting operation, consumers have felt
unpleasant feeling. Also, since the indoor space that has been
heated is cooled again, heating energy has been lost.
SUMMARY
[0006] Embodiments provide an air conditioner capable of performing
a heating operation even while a defrosting operation is
performed.
[0007] Embodiments also provide an air conditioner capable of
reducing unpleasant feeling of consumers and preventing heating
energy loss.
[0008] In one embodiment, an air conditioning system includes an
indoor heat exchange unit which exchanges heat with indoor air, and
an outdoor heat exchange unit which exchanges heat with outdoor
air, where the outdoor heat exchange unit performs a defrosting
operation to remove frost from the outdoor heat exchange unit while
the indoor heat exchange unit simultaneously performs a heating
operation to heat the indoor air.
[0009] The air conditioning system may also include a compressing
unit that discharges high temperature refrigerant, a switching unit
connected to a discharge side of the compressing unit, the outdoor
heat exchange unit being connected to the switching unit, an
expansion unit connected to the outdoor heat exchange unit, the
indoor heat exchange unit being connected to the expansion unit and
the switching unit, and a bypass unit that provides the high
temperature refrigerant discharged from the compressing unit to an
intake side of the outdoor heat exchange unit during the defrosting
operation.
[0010] The bypass unit may be connected to a refrigerant pipe
between the compressing unit and the switching unit, and may be
connected to a refrigerant pipe between the switching unit and the
indoor heat exchange unit.
[0011] The air conditioning system may also include a connecting
unit that provides refrigerant from a discharge side of the
expansion unit to a discharge side of the outdoor heat exchange
unit during the defrosting operation.
[0012] An accumulator including a heating unit may be disposed at
an intake side of the compressing unit.
[0013] The compressing unit may include a plurality of compressors,
and the bypass unit may provide refrigerant discharged from at
least one of the compressors to the intake side of the outdoor heat
exchange unit during the defrosting operation.
[0014] The air conditioning system may also include a refrigerant
pipe connecting the compressing unit to the switching unit, the
refrigerant pipe including a valve which is closed during the
defrosting operation.
[0015] The bypass unit may include a valve and a pressure
controller.
[0016] A heating unit that heats refrigerant may be disposed at an
intake side of the compressing unit.
[0017] In another embodiment, an air conditioning system includes a
bypass unit that provides refrigerant discharged from a compressing
unit to an intake side of an outdoor heat exchange unit during a
defrosting operation, and a connecting unit that provides expanded
refrigerant to a discharge side of the outdoor heat exchange unit
during the defrosting operation.
[0018] The bypass unit may be connected to a refrigerant pipe
between a switching unit and an indoor heat exchange unit, and a
refrigerant pipe between an expansion unit and the outdoor heat
exchange unit.
[0019] The connecting unit may be connected to a refrigerant pipe
between an expansion unit and the outdoor heat exchange unit, and a
refrigerant pipe between a switching unit and the outdoor heat
exchange unit.
[0020] The connecting unit may be connected to a refrigerant pipe
between an expansion unit and the bypass unit.
[0021] A heating unit that heats refrigerant may be disposed at an
intake side of the compressing unit.
[0022] In another embodiment, a method for controlling an air
conditioning system includes performing heat exchange with indoor
air to heat the indoor air, and simultaneously defrosting an
outdoor heat exchange unit when a defrosting operation is
triggered.
[0023] Defrosting the outdoor heat exchange unit may include
discharging refrigerant from a compressing unit, and providing a
portion of the discharged refrigerant to an intake side of the
outdoor heat exchange unit via a bypass unit.
[0024] The method may also include heating refrigerant introduced
to the compressing unit.
[0025] The defrosting operation may be triggered when the
temperature of the outdoor heat exchange unit is less than a
predetermined temperature.
[0026] An indoor heat exchange unit may perform the heat exchange
with the indoor air, and refrigerant discharged from the indoor
heat exchange unit may be provided to a discharge side of the
outdoor heat exchange unit via a connecting unit.
[0027] Refrigerant discharged from the indoor heat exchange unit
may be prevented from flowing into an intake side of the outdoor
heat exchange unit.
[0028] According to the present disclosure, an outdoor heat
exchange unit can be operated to remove frost even while heating an
indoor space. Furthermore, since an indoor space can be heated
during a defrosting operation, complaints of consumers can be
resolved and heating energy loss can be prevented.
[0029] According to the present disclosure, since temperature of
refrigerant introduced to a compressing unit during a defrosting
operation can be raised, temperature of refrigerant introduced to a
compressing unit can be raised. Furthermore, since the temperature
of refrigerant introduced to the compressing unit is raised,
temperature of refrigerant discharged from the compressing unit is
raised, so that heating efficiency and system efficiency can be
enhanced on the whole.
[0030] 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
claims.
[0031] 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
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a circuit diagram of an air conditioning system
according to an embodiment.
[0033] FIG. 2 is a flowchart of a frost removing operating method
of the air conditioning system of FIG. 1.
[0034] FIG. 3 is a P-h line graph illustrating phase change of
refrigerant while the air conditioning system of FIG. 1 operates to
remove frost.
[0035] FIG. 4 is a circuit diagram of an air conditioning system
according to another embodiment.
[0036] FIG. 5 is a flowchart of a frost removing operating method
of the air conditioning system of FIG. 4.
[0037] FIG. 6 is a P-h line graph illustrating phase change of
refrigerant while the air conditioning system of FIG. 4 operates to
remove frost.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Reference will now be made in detail to the embodiments of
the present disclosure, examples of which are illustrated in the
accompanying drawings. However, the present disclosure is not
limited to the embodiments, but other embodiments can be easily
made by adding, modifying, or deleting another elements, which may
also fall within the scope of the present disclosure.
[0039] FIG. 1 is a circuit diagram of an air conditioning system
according to an embodiment, FIG. 2 is a flowchart of a frost
removing operating method of the air conditioning system of FIG. 1,
and FIG. 3 is a P-h line graph illustrating phase change of
refrigerant while the air conditioning system of FIG. 1 operates to
remove frost.
[0040] Referring to FIG. 1, the air conditioning system includes a
compressing unit 10. The compressing unit 10 can include a
plurality of compressors 11 and 12. At this point, the compressing
unit 10 includes a main compressor 11 and a subcompressor 12. The
main compressor 11 operates during all operations, and the
subcompressor 12 can operate only when necessary. Also, the
compressing unit 10 can consist of one compressor.
[0041] Check valves 15 can be disposed at refrigerant pipes 111 on
the discharge side of the compressing unit 10, respectively, to
prevent refrigerant discharged from the compressing unit 10 from
flowing backward.
[0042] A switching unit 20 is connected to the refrigerant pipes
111 on the discharge side of the compressing unit 10. At this
point, examples of the switching unit 20 may include a 4-way valve.
The switching unit 20 controls a circulating direction of
refrigerant.
[0043] An indoor heat exchange unit 30 is connected to the
switching unit 20. An expansion unit 40 is connected to the indoor
heat exchange unit 30. Examples of the expansion unit 40 may
include a linear expansion valve (LEV) and a capillary tube that
expands refrigerant.
[0044] An outdoor heat exchange unit 50 is connected to the
expansion unit 40. The switching unit 20 is connected to the
outdoor heat exchange unit 50.
[0045] An accumulator 60 is disposed at the compressing unit 10 and
a refrigerant pipe 114 on the intake side of the switching unit 20.
The accumulator 60 provides only gas refrigerant of refrigerant
introduced from the switching unit 20 to the compressing unit 10.
The accumulator 60 can include a separate heating unit (not shown)
for heating refrigerant.
[0046] A bypass unit 110 branches off from the refrigerant pipe 111
of the compressing unit 10. At this point, the bypass unit 110 can
branch off from the refrigerant pipe 111 of the compressor 12 of
the compressing unit 10. That is, the bypass unit 110 can branch
off from the refrigerant pipe(s) 111 of one or more compressors of
the plurality of compressors 11 and 12.
[0047] The bypass unit 110 can be connected to a refrigerant pipe
112 connecting the discharge side of the expansion unit 40 and the
intake side of the compressing unit 10 during a heating operation.
For example, the bypass unit 110 is connected between the discharge
side of the expansion unit 40 and the refrigerant pipe 112 at the
intake side of the outdoor heat exchange unit 50 during a heating
operation.
[0048] The bypass unit 110 includes a first valve 101. At this
point, in the case where bypass units 110 branch off from
refrigerant pipes at the discharge sides of two or more compressors
11 and 12, respectively, the first valve 101 can be disposed at
each of the bypass units 110. Examples of the first valve 101 may
include an open/close valve for opening/closing the bypass unit
110.
[0049] Also, the bypass unit 110 can include a pressure controller
103 for controlling the pressure of refrigerant. The pressure
controller 103 controls the pressure of refrigerant such that
refrigerant discharged from the compressing unit 10 via the bypass
unit 110 has pressure similar to the pressure of refrigerant that
has passed through the expansion unit 40.
[0050] Also, a second valve 102 can be provided at a portion of the
refrigerant pipe 111 that is located between a portion branching
off from the bypass unit 110 and the switching unit 20. The second
valve 102 allows refrigerant discharged from predetermined
compressors 11 and 12 to be discharged to only the bypass unit
110.
[0051] An operation of an embodiment having the above-described
construction will be described below. The air conditioning system
can be selectively operated in a cooling or heating mode. A heating
operation will be described below.
[0052] Referring to FIGS. 1 and 2, when the air conditioning system
is operated in the heating mode (S11), refrigerant is compressed
with high temperature and high pressure by the compressing unit 10.
At this point, only the main compressor 11 can operate or both the
main compressor 11 and the subcompressor 12 can operate depending
on a heating capacity.
[0053] Refrigerant compressed by the compressing unit 10 is guided
to the indoor heat exchange unit 30 by the switching unit 20. At
this point, the first valve 101 is closed, and the second valve 102
is opened.
[0054] Heat exchange between refrigerant and indoor air is
performed at the indoor heat exchange unit 30. At this point, the
refrigerant that passes through the indoor heat exchange unit 30 is
condensed by exchanging heat with the indoor air. Also, the indoor
air that has exchanged heat with the refrigerant at the indoor heat
exchange unit 30 is discharged to an indoor space to heat the
indoor space.
[0055] Refrigerant discharged from the indoor heat exchange unit 30
reaches the expansion unit 40. The refrigerant is expanded to low
temperature and low pressure while passing through the expansion
unit 40. The expanded refrigerant flows into the outdoor heat
exchange unit 50. The refrigerant of the outdoor heat exchange unit
50 absorbs heat from outside air to change into a gas state.
[0056] Refrigerant discharged from the outdoor heat exchange unit
50 flows into the switching unit 20, which performs a switching
operation such that the refrigerant flows into the accumulator 60.
The accumulator 60 allows only gas refrigerant to flow into the
compressing unit 10.
[0057] Meanwhile, when the heating operation is performed under low
outside temperature condition, humidity contained in outside air is
formed on the surface of the outside heat exchange unit 50. When
the humidity is frozen on the surface of the outside heat exchange
unit 50, it changes into frost. At this point, since the outside
heat exchange unit 50 serves as an evaporator, the frost of the
outside heat exchange unit 50 hinders a heat exchange operation
between the outside heat exchange unit 50 and the outside air.
Also, since the temperature of the refrigerant discharged from the
outside heat exchanger unit 50 is lowered, the temperature of
refrigerant flowing into the compressing unit 10 is also lowered.
Therefore, the temperature of refrigerant discharged from the
compressing unit 10 is lowered, which reduces heating efficiency of
the air conditioning system.
[0058] To prevent reduction in heating efficiency of the air
conditioning system, when more than a predetermined amount of frost
is formed on the outside heat exchange unit 50, a defrosting
operation for melting the frost formed on the outside heat exchange
unit 50 is performed. At this point, during the defrosting
operation, the temperature of the outside heat exchange unit 50 is
detected, and whether the detected temperature is less than a
predetermined temperature is judged (S12). When the detected
temperature is less than the predetermined temperature, the
defrosting operation is performed.
[0059] Also, the defrosting operation can be performed when the
heating operation is performed for a predetermined time. At this
point, the heating operating time should be set in advance in a
control unit (not shown) to correspond to each outside
temperature.
[0060] When the defrosting operation starts, refrigerant discharged
from the compressing unit 10 sequentially flows through the
switching unit 20, the indoor heat exchange unit 30, the expansion
unit 40, and the outdoor heat exchange unit 50. At this point, high
temperature refrigerant discharged from the compressing unit 10
continuously flows into the indoor heat exchange unit 30 to heat an
indoor space. Also, this refrigerant flowing is substantially the
same as that during a heating operation.
[0061] Simultaneously, the first valve 101 is opened (S13), and the
second valve 102 is closed. At this point, a portion of refrigerant
from the compressing unit 10 flows along the bypass unit 110. The
refrigerant flowing through the bypass unit 110 is controlled to
have a predetermined pressure by the pressure controller 103. Also,
an amount of refrigerant flowing into the switching unit 20 can be
increased by slightly opening an opening degree of the second valve
102.
[0062] High temperature refrigerant of the bypass unit 110 flows
into the refrigerant pipe 112 on the intake side of the outdoor
heat exchange unit 50. At this point, the high temperature
refrigerant of the bypass unit 110 mixes with low temperature
refrigerant discharged from the expansion unit 40. Therefore, the
mixed refrigerant in the refrigerant pipe 112 on the intake side of
the outdoor heat exchange unit 50 has temperature considerably
raised in comparison with the temperature of the refrigerant
discharged from the expansion unit 40.
[0063] The mixed refrigerant of the refrigerant pipe 112 flows into
the outdoor heat exchange unit 50. The mixed refrigerant melts
frost formed on the surface of the outdoor heat exchange unit 50.
At this point, the refrigerant discharged from the outdoor heat
exchange unit 50 has relatively higher temperature than that of the
discharged refrigerant in the heating operation. Therefore, the
temperature of refrigerant is raised at the intake side of the
compressing unit 10, so that the performance of the air
conditioning system is enhanced on the whole.
[0064] An indoor space can be heated and simultaneously frost
formed on the outdoor heat exchange unit 50 can be removed by
allowing high temperature refrigerant to flow into the intake side
of the outdoor heat exchange unit 50 (S14). Therefore, a heating
operation does not need to be suspended in order to perform a
separate defrosting operation.
[0065] In the above description, though an operation for removing
frost formed on the outdoor heat exchange unit 50 is referred to as
the defrosting operation, the front removing operation according to
the present disclosure means an operation where a heating operation
and a defrosting operation are performed simultaneously.
[0066] Referring to FIG. 3, assuming that a heating operation cycle
and a defrosting cycle are ideally performed, refrigerant changes
along a line of C1-C2-C3-C4-C1 during the heating operation cycle,
and refrigerant changes along a line of C6-C7-C3-C5-C7 during the
defrosting cycle.
[0067] At this point, a pressure at the discharge side of the
compressing unit 10 becomes C1, and a pressure at the discharge
side of the expansion unit 40 becomes C2 during the heating
operation cycle.
[0068] On the other hand, during the defrosting cycle, a pressure
at the discharge side of the compressing unit 10 becomes P1. At
this point, since a portion of compressed refrigerant is bypassed
to the refrigerant pipe 112 on the intake side of the outdoor heat
exchange unit 50 via the bypass unit 110, the pressure of the
portion of the compressed refrigerant becomes C3 while it passes
through the expansion unit 40. Also, since the bypassed refrigerant
mixes with refrigerant at the exit side of the expansion unit 40,
the pressure of the mixed refrigerant is raised to C3, and the
temperature is also raised. At this point, since the temperature at
the entry side of the outdoor heat exchange unit 50 is raised in
comparison with that during the heating operation, the frost formed
on the surface of the outdoor heat exchange unit 50 is removed.
Also, the temperature of refrigerant discharged from the outdoor
heat exchange unit 50 is raised in comparison with that during the
heating operation, the temperature of refrigerant at the entry side
of the compressing unit 10 is also raised. Accordingly, the
defrosting cycle moves upward in FIG. 3, so that efficiency of the
air conditioning system is enhanced on the whole.
[0069] Next, an air conditioning system according to another
embodiment will be described below.
[0070] FIG. 4 is a circuit diagram of an air conditioning system
according to another embodiment, FIG. 5 is a flowchart of a frost
removing operating method of the air conditioning system of FIG. 4,
FIG. 6 is a P-h line graph illustrating phase change of refrigerant
while the air conditioning system of FIG. 4 operates to remove
frost.
[0071] Referring to FIG. 4, the air conditioning system includes a
compressing unit 201 for compressing refrigerant in high pressure.
A switching unit 202 is connected to the refrigerant discharge side
of the compressing unit 201. Examples of the switching unit 202
include a 4-way valve.
[0072] An outdoor heat exchange unit 203, an indoor heat exchange
unit 205, and an accumulator 206 are connected to the switching
unit 202. The accumulator 206 is connected to the refrigerant
intake side of the compressing unit 201. An expansion unit 204 is
installed at a refrigerant pipe connecting the outdoor heat
exchange unit 203 with the indoor heat exchange unit 205. Examples
of the expansion unit 204 may include an LEV and a capillary
tube.
[0073] The refrigerant pipe between the switching unit 202 and the
indoor heat exchange unit 205, and the refrigerant pipe between the
expansion unit 204 and the outdoor heat exchange unit 203 are
connected to a bypass unit 210, which can include an open/close
valve 211. Also, the bypass unit 210 can be provided with a
pressure controller 212. The pressure controller 212 reduces the
pressure of refrigerant such that the pressure of the refrigerant
becomes similar to that of refrigerant from the expansion unit 204
when the refrigerant discharged from the compressing unit 201 flows
into the refrigerant pipe between the expansion unit 204 and the
outdoor heat exchange unit 203 via the bypass unit 210.
[0074] The refrigerant pipe between the expansion unit 204 and the
outdoor heat exchange unit 203, and the refrigerant pipe between
the switching unit 202 and the outdoor heat exchange unit 203 are
connected to a connecting unit 220. At this point, the connecting
unit 220 can be connected to the refrigerant pipe between the
expansion unit 204 and the bypass unit 210. The connecting unit 220
can be provided with an open/close valve 221. The open/close valve
221 can be disposed at a portion where the refrigerant pipe between
the expansion unit 204 and the outdoor heat exchange unit 203, and
the connecting unit 220 are connected to each other. At this point,
examples of the open/close valve 221 may include a 3-way valve.
Also, the open/close valve 221 can be disposed at the connecting
unit 220. The connecting unit 220 can be provided with a pressure
controller (not shown).
[0075] A heating unit 207 can be disposed inside the accumulator
206. At this point, the heating unit 207 heats refrigerant received
in the accumulator 206.
[0076] An operation of the air conditioning system having the
above-described construction will be described below.
[0077] Referring to FIGS. 4 and 5, the air conditioning system is
operated in a cooling or heating mode as refrigerant is circulated
in one or the other direction. Refrigerant cycle during the cooling
operation is opposite to that during the heating operation.
Accordingly, only heating operation will be described below.
[0078] When the air conditioning system is operated in a heating
mode, refrigerant compressed by the compressing unit 201 flows into
the switching unit 202. The switching unit 202 performs a switching
operation such that the refrigerant flows into the indoor heat
exchange unit 205. At this point, the open/close valve 211 of the
bypass unit 210 is closed.
[0079] Refrigerant flowing through the indoor heat exchange unit
205 exchanges heat with indoor air to heat an indoor space. At this
point, the indoor heat exchange unit 203 serves as a condenser.
[0080] Refrigerant condensed by the indoor heat exchange unit 205
flows into the expansion unit 204 and is expanded with low
temperature and low pressure. The expanded refrigerant flows into
the outdoor heat exchange unit 203. Refrigerant of the outdoor heat
exchange unit 203 exchanges heat with outside air. At this point,
the outdoor heat exchange unit 203 serves as an evaporator.
[0081] Refrigerant of the outdoor heat exchange unit 203 flows into
the switching unit 202. At this point, the open/close valve 221 of
the connecting unit 220 is closed.
[0082] The switching unit 202 performs a switching operation such
that refrigerant introduced from the outdoor heat exchange unit 203
flows into the accumulator 206. Only gas phase refrigerant of
refrigerant that has flowed into the accumulator 206 flows into the
compressing unit 201. At this point, the heating unit 207 of the
accumulator 206 operates to heat the refrigerant of the accumulator
206. Then, the temperature of the refrigerant introduced into the
compressing unit 201 is raised, so that efficiency of the heating
cycle can be enhanced.
[0083] When outdoor temperature is low during a heating operation
of the air conditioning system, humidity contained in air is formed
on the surface of the outdoor heat exchange unit 203. At this
point, when frost is formed on the outdoor heat exchange unit 203,
the heat exchange performance of the outdoor heat exchange unit 203
considerably reduces.
[0084] To prevent reduction in the heating efficiency of the air
conditioning system, a defrosting operation for melting frost
formed on the outdoor heat exchange unit 203 is performed when more
than a predetermined amount of frost is formed on the outdoor heat
exchange unit 203.
[0085] At this point, during the defrosting operation, the
temperature of the outside heat exchange unit 203 is detected, and
whether the detected temperature is less than a predetermined
temperature is judged (S22). When the detected temperature is less
than the predetermined temperature, the defrosting operation is
performed.
[0086] Also, the defrosting operation can be performed when the
heating operation is performed for a predetermined time. At this
point, the heating operating time should be set in advance in a
control unit (not shown) to correspond to each outside
temperature.
[0087] When the defrosting operation starts (S23), refrigerant
discharged from the compressing unit 201 flows into the switching
unit 202 and the indoor heat exchange unit 205. At this point, the
open/close valve 211 of the bypass unit 210 is opened (S24).
[0088] At this point, a portion of refrigerant discharged from the
switching unit 202 flows into the intake side of the outdoor heat
exchange unit 203 via the bypass unit 210 to remove frost formed on
the outdoor heat exchange unit 203 (S23).
[0089] Simultaneously, a portion of refrigerant discharged from the
switching unit 202 flows into the indoor heat exchange unit 205. At
this point, the high temperature refrigerant of the indoor heat
exchange unit 205 heat an indoor space.
[0090] Refrigerant discharged from the indoor heat exchange unit
205 sequentially flows into the expansion unit 204. At this point,
the valve 221 of the connecting unit 220 is switched such that
refrigerant discharged from the expansion unit 204 flows to the
discharge side of the outdoor heat exchange unit 203 (S25). At this
point, the refrigerant discharged from the outside heat exchange
unit 203 mixes with expanded refrigerant flowing through the
connecting unit 220. Also, the refrigerant expanded by the
expansion unit 204 is prevented from flowing into the outside heat
exchange unit 203 by the valve 221 of the connecting unit 220.
[0091] As descried above, the indoor space is heated and
simultaneously frost formed on the outside heat exchange unit 203
can be removed (S14). Therefore, a heating operation does not need
to be suspended to perform a separate defrosting operation.
[0092] In the above description, though an operation for removing
frost formed on the outdoor heat exchange unit 203 is referred to
as the defrosting operation, the front removing operation according
to the present disclosure means an operation where a heating
operation and a defrosting operation are performed
simultaneously.
[0093] Whether a defrosting operation of the outdoor heat exchange
unit 203 has been completed is judged (S26). At this point, when
the temperature of the outdoor heat exchange unit 203 reaches a
predetermined temperature, it is judged that the defrosting
operation has been completed. When it is judged that the defrosting
operation has been completed, a heating operation starts again
(S21).
[0094] Referring to FIG. 6, when the heating operation is
performed, refrigerant changes its phase while it passes through a
process of {circle around (1)}.fwdarw.{circle around
(2)}.fwdarw.{circle around (5)}.fwdarw.{circle around (6)}.
[0095] When the defrosting operation is performed, refrigerant that
has flowed into the indoor heat exchange unit 205, of refrigerant
that has passed through the compressor 201 is lowered in its
temperature while it passes through a process of {circle around
(2)}.fwdarw.{circle around (5)}. On the other hand, refrigerant
bypassed by the bypass unit 210 passes through a process of {circle
around (2)}.fwdarw.{circle around (3)} by the pressure controller
212, and is lowered in its pressure to the pressure at the entry of
the outdoor heat exchange unit 203.
[0096] Also, the bypassed refrigerant passes through {circle around
(3)}.fwdarw.{circle around (4)} while it passes through the outdoor
heat exchange unit 203. Here, while the bypassed refrigerant passes
through the outdoor heat exchange unit 203, the temperature of a
pipe of the outdoor heat exchange unit 203 is raised. Also, frost
on the outdoor heat exchange unit 203 is removed by the bypassed
refrigerant.
[0097] Meanwhile, refrigerant that passes through the indoor heat
exchange unit 205 undergoes a process of {circle around
(5)}.fwdarw.{circle around (6)} while it passes through the
expansion unit 204. Also, the bypassed refrigerant and the
refrigerant that has passed through the expansion unit 204 merge at
the exit of the outdoor heat exchange unit 203. In detail, during a
refrigerant mixing process, refrigerant that has passed through the
outdoor heat exchange unit 203 is lowered in its temperature while
it undergoes a process of {circle around (4)}.fwdarw.{circle around
(7)}, and refrigerant that has passed through the expansion unit
204 is raised in its temperature while it undergoes a process of
{circle around (6)}.fwdarw.{circle around (7)}.
[0098] Meanwhile, the refrigerant that has merged at the exit of
the outdoor heat exchange unit 203 flows into the accumulator 206,
and is heated at the heating unit 207. That is, the mixed
refrigerant is overheated inside the accumulator 207 to undergo a
process of {circle around (7)}.fwdarw.{circle around (1)}. After
that, the refrigerant is introduced to the entry of the compressing
unit 201 by the switching unit 202.
[0099] As described above, frost formed on the outdoor heat
exchange unit 203 can be removed without suspension of a heating
operation. Therefore, the defrosting operation according to the
present disclosure means a heating operation and a defrosting
operation are performed simultaneously.
[0100] According to the present disclosure, a heating operation is
performed even during a defrosting operation to reduce unpleasant
feeling of a consumer, and reduce heating energy.
[0101] 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, various
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.
[0102] The foregoing embodiments and advantages are merely
exemplary and are not to be construed as limiting the present
invention. The present teaching can be readily applied to other
types of apparatuses. The description of the present invention is
intended to be illustrative, and not to limit the scope of the
claims. Many alternatives, modifications, and variations will be
apparent to those skilled in the art.
[0103] The illustrations of the embodiments described herein are
intended to provide a general understanding of the structure of the
various embodiments. The illustrations are not intended to serve as
a complete description of all of the elements and features of
apparatus and systems that utilize the structures or methods
described herein. Many other embodiments may be apparent to those
of skill in the art upon reviewing the disclosure. Other
embodiments may be utilized and derived from the disclosure, such
that structural and logical substitutions and changes may be made
without departing from the scope of the disclosure. Accordingly,
the disclosure and the figures are to be regarded as illustrative
rather than restrictive.
[0104] One or more embodiments of the disclosure may be referred to
herein, individually and/or collectively, by the term "invention"
merely for convenience and without intending to voluntarily limit
the scope of this application to any particular invention or
inventive concept. Moreover, although specific embodiments have
been illustrated and described herein, it should be appreciated
that any subsequent arrangement designed to achieve the same or
similar purpose may be substituted for the specific embodiments
shown. This disclosure is intended to cover any and all subsequent
adaptations or variations of various embodiments. Combinations of
the above embodiments, and other embodiments not specifically
described herein, will be apparent to those of skill in the art
upon reviewing the description.
[0105] The above disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments which fall within the true spirit and scope of the
present invention. Thus, to the maximum extent allowed by law, the
scope of the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
[0106] Although the invention has been described with reference to
several exemplary embodiments, it is understood that the words that
have been used are words of description and illustration, rather
than words of limitation. As the present invention may be embodied
in several forms without departing from the spirit or essential
characteristics thereof, it should also be understood that the
above-described embodiments are not limited by any of the details
of the foregoing description, unless otherwise specified. Rather,
the above-described embodiments should be construed broadly within
the spirit and scope of the present invention as defined in the
appended claims. Therefore, changes may be made within the metes
and bounds of the appended claims, as presently stated and as
amended, without departing from the scope and spirit of the
invention in its aspects.
* * * * *