U.S. patent application number 14/925499 was filed with the patent office on 2016-05-05 for air conditioner and method of controlling the same.
The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Donghwi KIM, Junseong PARK, Ilyoong SHIN.
Application Number | 20160123645 14/925499 |
Document ID | / |
Family ID | 54360946 |
Filed Date | 2016-05-05 |
United States Patent
Application |
20160123645 |
Kind Code |
A1 |
KIM; Donghwi ; et
al. |
May 5, 2016 |
AIR CONDITIONER AND METHOD OF CONTROLLING THE SAME
Abstract
An air conditioner includes a compressor; a flow switching part
disposed at an outlet side of the compressor to switch a flow
direction of a refrigerant according to whether a cooling operation
or heating operation is performed; an outdoor heat exchanger
connected to the flow switching part and having a plurality of the
refrigerant pipes to guide the refrigerant which heat-exchanges
with outdoor air; and a main expansion valve connected to one side
of the outdoor heat exchanger. A first inlet/outlet pipe connects
the flow switching part to the outdoor heat exchanger; and a second
inlet/outlet pipe connects the outdoor heat exchanger to the main
expansion valve, where the outdoor heat exchanger includes a header
to form a flowing space of the refrigerant and having an upper
header and a lower header; a check valve disposed between the upper
header and the lower header to guide the refrigerant to flow one
way; and a bypass pipe connecting the lower header to the second
inlet/outlet pipe and guiding a discharge of a liquid refrigerant
located in the lower header, and a bypass pipe valve controlling an
amount of the liquid refrigerant flowing through the bypass
pipe.
Inventors: |
KIM; Donghwi; (Seoul,
KR) ; PARK; Junseong; (Seoul, KR) ; SHIN;
Ilyoong; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Family ID: |
54360946 |
Appl. No.: |
14/925499 |
Filed: |
October 28, 2015 |
Current U.S.
Class: |
62/115 ;
62/160 |
Current CPC
Class: |
F25B 2600/2501 20130101;
F25B 39/00 20130101; F25B 49/02 20130101; F25B 13/00 20130101; F25B
2700/04 20130101; F25B 2313/02541 20130101; F25B 2313/02533
20130101; F25B 2313/0315 20130101 |
International
Class: |
F25B 49/02 20060101
F25B049/02; F25B 13/00 20060101 F25B013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2014 |
KR |
10-2014-0147976 |
Oct 29, 2014 |
KR |
10-2014-0147977 |
Oct 29, 2014 |
KR |
10-2014-0147978 |
Claims
1. An air conditioner comprising: a compressor; a flow switching
part disposed at an outlet side of the compressor to switch a flow
direction of a refrigerant according to whether a cooling operation
or heating operation is performed; an outdoor heat exchanger
connected to the flow switching part and having a plurality of the
refrigerant pipes to guide the refrigerant which heat-exchanges
with outdoor air; a main expansion valve connected to one side of
the outdoor heat exchanger; a first inlet/outlet pipe connecting
the flow switching part to the outdoor heat exchanger; and a second
inlet/outlet pipe connecting the outdoor heat exchanger to the main
expansion valve, wherein the outdoor heat exchanger comprises: a
header to form a flowing space of the refrigerant and including an
upper header and a lower header; a check valve disposed between the
upper header and the lower header to guide the refrigerant to flow
one way; a bypass pipe connecting the lower header to the second
inlet/outlet pipe and to guide a discharge of a liquid refrigerant
located in the lower header; and a bypass pipe valve that is
installed on the bypass pipe and controls an amount of the liquid
refrigerant flowing through the bypass pipe.
2. The air conditioner according to claim 1, further comprising a
detector disposed in the refrigerant flowing space of the header to
detect the amount of the liquid refrigerant in the lower
header.
3. The air conditioner according to claim 2, wherein the detector
comprises a liquid level sensor disposed in the refrigerant flowing
space of the header to detect a level of the liquid refrigerant
introduced into the lower header.
4. The air conditioner according to claim 3, wherein the liquid
level sensor comprises a first liquid level sensor disposed at a
lower side of the lower header such that a plurality of liquid
level sensors are disposed above the first liquid level sensor.
5. The air conditioner according to claim 2, wherein the detector
comprises a temperature sensor disposed in the refrigerant flowing
space of the header to detect a temperature of the liquid
refrigerant introduced into the lower header.
6. The air conditioner according to claim 5, wherein the
temperature sensor comprises a first temperature sensor disposed at
a lower side of the lower header such that a second temperature
sensor is disposed above the first temperature sensor.
7. The air conditioner according to claim 2, wherein, when the
amount of the liquid refrigerant measured by the detector is more
than a set range, the bypass pipe valve is opened, and the liquid
refrigerant stored in the outdoor heat exchanger is discharged from
the outdoor heat exchanger, and when the amount of the liquid
refrigerant measured by the detector is less than the set range,
the bypass pipe valve is closed.
8. The air conditioner according to claim 1, wherein the outdoor
heat exchanger further comprises a first refrigerant pipe connected
to the upper header; a connection pipe to guide the refrigerant
flowing through the first refrigerant pipe to the lower header; and
a refrigerant introduction pipe connecting the lower header to a
second refrigerant pipe, and the refrigerant introduction pipe
located higher than the connection pipe.
9. The air conditioner according to claim 8, wherein the
refrigerant introduction pipe comprises a lower introduction pipe
disposed at a lower side of the lower header such that a plurality
of upper introduction pipes is disposed above the lower
introduction pipe, and a height of the lower introduction pipe is
higher than a height of the connection pipe with respect to a
bottom of the outdoor heat exchanger.
10. The air conditioner according to claim 1, wherein the bypass
pipe extends from a surface of the lower header.
11. The air conditioner according to claim 1, wherein the bypass
pipe valve comprises an electronic expansion valve of which a
degree of opening is controllable.
12. The air conditioner according to claim 1, further comprising:
first and second distribution pipes branching from the second
inlet/outlet pipe; and a first and second distributors connected to
the respective first and second distribution pipes to branch and
introduce the refrigerant into the plurality of refrigerant
pipes.
13. The air conditioner according to claim 12, wherein the first
distributor is connected to the first distribution pipe and in
communication with the upper header; and the second distributor is
connected to the second distribution pipe and in communication with
the lower header.
14. The air conditioner according to claim 12, further comprising:
a first valve device disposed at the first distribution pipe; and a
second valve device disposed at the second distribution pipe.
15. The air conditioner according to claim 8, further comprising a
third valve device disposed at the connection pipe.
16. A method of controlling an air conditioner, comprising: driving
a cooling operation in an indoor unit to allow refrigerant
discharged from a compressor to be introduced into the outdoor heat
exchanger; detecting an amount of a liquid refrigerant introduced
into the outdoor heat exchanger by a detector; and controlling a
degree of opening of a valve disposed at a bypass pipe to discharge
the liquid refrigerant from the outdoor heat exchanger, by a
controller based on the detected amount of the liquid
refrigerant.
17. The method according to claim 16, wherein the controller
controls by opening the bypass pipe valve when the amount of the
liquid refrigerant detected by the detector is more than a set
range, and closes the bypass pipe valve when the amount of the
liquid refrigerant is less than the set range.
18. The method according to claim 16, wherein the detector
comprises a temperature sensor disposed at a refrigerant path of
the outdoor heat exchanger to detect a temperature of the
refrigerant, and the controller determines the amount of the liquid
refrigerant introduced into the outdoor heat exchanger based on a
temperature value of the refrigerant detected by the temperature
sensor.
19. The method according to claim 18, wherein the temperature
sensor comprises: a first temperature sensor disposed at a lower
side of the lower header; and a second temperature sensor disposed
above the first temperature sensor.
20. The method according to claim 16, wherein the detector
comprises a liquid level sensor disposed at a refrigerant path of
the outdoor heat exchanger to detect a level of the liquid
refrigerant, and the controller determines the amount of the liquid
refrigerant introduced into the outdoor heat exchanger based on a
level value of the liquid refrigerant detected by the liquid level
sensor.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority under 35 U.S.C. .sctn.119
to Korean Application No. 10-2014-0147976, filed in Korea on Oct.
29, 2014, No. 10-2014-0147977, filed in Korea on Oct. 29, 2014 and
No. 10-2014-0147978, filed in Korea on Oct. 29, 2014, whose entire
disclosure is hereby incorporated by reference.
BACKGROUND
[0002] 1. Field
[0003] An air conditioner and a method of controlling the same are
disclosed herein.
[0004] 2. Background
[0005] An air conditioner is an apparatus which maintains air in a
desired space at a desired temperature. Generally, the air
conditioner includes a compressor, a condenser, an expander and an
evaporator, and drives a refrigerant cycle by performing a
compression process, a condensation process, an expansion process
and an evaporation process of a refrigerant, and thus the desired
space may be heated or cooled.
[0006] The desired space may be a space according to a place in
which the air conditioner is used. For example, when the air
conditioner is disposed at home or an office, the desired space may
be an indoor space of a house or a building. When the air
conditioner is disposed in a vehicle, the desired space may be a
passenger compartment.
[0007] When the air conditioner performs a cooling operation, an
outdoor heat exchanger provided at an outdoor unit serves as the
condenser, and an indoor heat exchanger provided at an indoor unit
serves as the evaporator. However, when the air conditioner
performs a heating operation, the indoor heat exchanger serves as
the condenser, and the outdoor heat exchanger serves as the
evaporator.
[0008] FIG. 1 is a view illustrating a structure of a conventional
outdoor heat exchanger.
[0009] Referring to FIG. 1, the conventional outdoor heat exchanger
1 includes a plurality of refrigerant pipes 2 which are arranged in
a plurality of rows, a coupling plate 3 to which ends of the
refrigerant pipes 2 are coupled, and which supports the refrigerant
pipes 2, and a header 4 which branches the refrigerant into the
refrigerant pipes 2 or combines the refrigerant passed through the
refrigerant pipes 2.
[0010] The outdoor heat exchanger 1 further includes a return tube
7 which changes a flow direction of the refrigerant from one
refrigerant pipe 2 to another refrigerant pipe. For example, the
return tube 7 may change the flow direction of the refrigerant from
one refrigerant pipe 2, which is located in a first row of the
refrigerant pipes 2 disposed in two rows, to another refrigerant
pipe located in a second row.
[0011] The outdoor heat exchanger 1 further includes a plurality of
distributors 5 and 6. The plurality of distributors 5 and 6 include
a first distributor 5 which branches and introduces the refrigerant
into at least a part of the refrigerant pipes among the plurality
of refrigerant pipes 2, and a second distributor 6 which branches
and introduces the refrigerant into the rest of the plurality of
refrigerant pipes 2.
[0012] In the outdoor heat exchanger 1 as described above, opposing
flow directions of the refrigerant are respectively formed in the
heating and cooling operations.
[0013] For example, when the air conditioner performs the cooling
operation, the outdoor heat exchanger 1 serves as the condenser
(referring to a solid line arrow).
[0014] Specifically, the high pressure refrigerant compressed in
the compressor is introduced into the header 4, branched into the
plurality of refrigerant pipes 2, and heat-exchanged with outdoor
air while flowing through the refrigerant pipes 2. The
heat-exchanged refrigerant is combined at the first and second
distributors 5 and 6, and then flows toward the indoor heat
exchanger.
[0015] On the other hand, when the air conditioner performs the
heating operation, the outdoor heat exchanger 1 serves as the
evaporator (referring to a dotted line arrow).
[0016] Specifically, the refrigerant condensed in the indoor heat
exchanger may be depressurized while passing through the expander,
and then may be introduced into the outdoor heat exchanger 1. The
refrigerant is branched into the first and second distributors 5
and 6 at an entrance side of the outdoor heat exchanger 1, and then
introduced into the refrigerant pipes 2 through a plurality of
branch pipes connected to each distributor.
[0017] At this time, the refrigerant is heat-exchanged with the
outdoor air while flowing through the refrigerant pipes 2, and the
heat-exchanged refrigerant may be combined at the header 4 and then
may flow toward the compressor.
[0018] When the air conditioner performs the cooling operation, the
refrigerant passing through the outdoor heat exchanger 1 may be at
a high temperature and high pressure gaseous state. At this time,
to increase condensation efficiency of the refrigerant, it is
advantageous to reduce the number of paths branched to the outdoor
heat exchanger 1 and to increase a length of each of the paths.
[0019] That is, by increasing a length of a flow path of the
refrigerant, a flow speed of the refrigerant may be increased, and
thus a condensing pressure of the refrigerant may be reduced.
Therefore, the condensation efficiency, i.e., a phase change rate
to a liquid state may be improved.
[0020] However, when the air conditioner performs the heating
operation, the refrigerant passing through the outdoor heat
exchanger 1 has two phases, a gaseous refrigerant and a liquid
refrigerant. At this time, to reduce a pressure loss of the
refrigerant, it is advantageous to increase the number of the paths
branched to the outdoor heat exchanger 1 and to reduce the length
of each of the paths.
[0021] That is, a gaseous refrigerant of the two-phase refrigerant
may have a large pressure loss during flow. By reducing the length
of the flow path of the refrigerant and increasing the number of
the paths, the pressure loss, i.e., an evaporating pressure drop
may be prevented, and thus evaporation efficiency may be
improved.
[0022] However, according to the structure of the conventional
outdoor heat exchanger as illustrated in FIG. 1, when the air
conditioner performs the cooling operation and the heating
operation, the number of the paths through which the refrigerant is
branched to the outdoor heat exchanger and the length of each of
the paths are formed equally, and thus there is a problem that the
heat exchange efficiency is reduced.
[0023] That is, in the cooling operation, the condensing pressure
in the outdoor heat exchanger is increased, and thus the
condensation efficiency is degraded. In the heating operation, the
evaporating pressure in the outdoor heat exchanger is reduced, and
thus the evaporation efficiency is degraded.
SUMMARY
[0024] Therefore, the present disclosure is directed to an air
conditioner having an outdoor heat exchanger in which heat exchange
efficiency is improved, and a method of controlling the same.
[0025] According to an aspect, there is provided an air conditioner
including a compressor; a flow switching part disposed at an outlet
side of the compressor to switch a flow direction of a refrigerant
according to whether a cooling operation or heating operation is
performed; an outdoor heat exchanger connected to the flow
switching part and having a plurality of the refrigerant pipes to
guide the refrigerant which heat-exchanges with outdoor air; a main
expansion valve connected to one side of the outdoor heat
exchanger; a first inlet/outlet pipe connecting the flow switching
part to the outdoor heat exchanger; and a second inlet/outlet pipe
connecting the outdoor heat exchanger to the main expansion valve,
wherein the outdoor heat exchanger includes a header to form a
flowing space of the refrigerant and having an upper header and a
lower header; a check valve disposed between the upper header and
the lower header to guide the refrigerant to flow one way; and a
bypass pipe connecting the lower header to the second inlet/outlet
pipe and to guide a discharge of a liquid refrigerant located in
the lower header, and a bypass pipe valve which controls an amount
of the liquid refrigerant flowing through the bypass pipe.
[0026] The air conditioner may further include a detector disposed
in the refrigerant flowing space of the header to detect the amount
of the liquid refrigerant in the lower header.
[0027] The detector may include a liquid level sensor disposed in
the refrigerant flowing space of the header to detect a level of
the liquid refrigerant introduced into the lower header.
[0028] The liquid level sensor may include a first liquid level
sensor disposed at a lower side of the lower header such that a
plurality of liquid level sensors are disposed above the first
liquid level sensor.
[0029] The detector may include a temperature sensor disposed in
the refrigerant flowing space of the header to detect a temperature
of the liquid refrigerant introduced into the lower header.
[0030] The temperature sensor may include a first temperature
sensor disposed at a lower side of the lower header such that a
second temperature sensor provided above the first temperature
sensor.
[0031] When the amount of the liquid refrigerant measured by the
detector is more than a set range, the bypass pipe valve may be
opened, and thus the refrigerant stored in the outdoor heat
exchanger may be discharged from the outdoor heat exchanger, and
when the amount of the liquid refrigerant measured by the detector
is less than the set range, the bypass pipe valve may be
closed.
[0032] The outdoor heat exchanger may further include a first
refrigerant pipe connected to the upper header; a connection pipe
to guide the refrigerant flowing through the first refrigerant pipe
to the lower header; and a refrigerant introduction pipe connecting
the lower header to a second refrigerant pipe, and the refrigerant
introduction pipe may be higher than the connection pipe.
[0033] The refrigerant introduction pipe may include a lower
introduction pipe disposed at a lower side of the lower header such
that a plurality of upper introduction pipes is disposed above the
lowermost introduction pipe, and a height of the lower introduction
pipe may be higher than a height of the connection pipe with
respect to a bottom of the outdoor heat exchanger.
[0034] The bypass pipe may extend from a surface of the lower
header.
[0035] The bypass pipe valve may include an electronic expansion
valve of a degree of opening is controllable.
[0036] The air conditioner may further include first and second
distribution pipes branching from the second inlet/outlet pipe; and
a first and second distributors connected to the respective first
and second distribution pipes to branch and introduce the
refrigerant into the plurality of refrigerant pipes.
[0037] The first distributor is connected to the first distribution
pipe and in communication with the upper header; and a second
distributor is connected to the second distribution pipe and in
communication with the lower header.
[0038] The air conditioner may further include a first valve device
disposed at the first distribution pipe; and a second valve device
disposed at the second distribution pipe.
[0039] The air conditioner may further include a third valve device
disposed at the connection pipe.
[0040] According to another aspect, there is provided method of
controlling an air conditioner, including driving a cooling
operation in an indoor unit; heat-exchanging a refrigerant to be
discharged to the indoor unit through an outdoor heat exchanger,
and introducing the refrigerant into the outdoor heat exchanger;
detecting an amount of a liquid refrigerant introduced into the
outdoor heat exchanger through a detector; and controlling a degree
of opening of a valve disposed at a bypass pipe to discharge the
liquid refrigerant from the outdoor heat exchanger, by a controller
based on the detected amount of the liquid refrigerant.
[0041] The controller controls by opening the bypass pipe valve
when the amount of the liquid refrigerant detected by the detector
is more than a set range, and may close the bypass pipe valve, when
the amount of the liquid refrigerant is less than the set
range.
[0042] The detector may include a temperature sensor disposed at a
refrigerant path of the outdoor heat exchanger to detect a
temperature of the refrigerant, and the amount of the liquid
refrigerant introduced into the outdoor heat exchanger may be
detected through a temperature value of the refrigerant detected by
the temperature sensor.
[0043] The temperature sensor may include a first temperature
sensor disposed at a lower side of the lower header; and a second
temperature sensor disposed above the first temperature sensor.
[0044] The detector may include a liquid level sensor disposed at a
refrigerant path of the outdoor heat exchanger to detect a level of
the liquid refrigerant, and the amount of the liquid refrigerant
introduced into the outdoor heat exchanger may be detected through
a level value of the liquid refrigerant detected by the liquid
level sensor.
[0045] 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
[0046] Embodiments will be described in detail with reference to
the following drawings in which like reference numerals refer to
like elements, and wherein:
[0047] FIG. 1 is a view illustrating a conventional outdoor heat
exchanger;
[0048] FIG. 2 is a view illustrating a structure of an air
conditioner according to an embodiment of the present
invention;
[0049] FIG. 3 is a view illustrating a main structure of an outdoor
heat exchanger according to the embodiment of the present
invention;
[0050] FIG. 4 is an enlarged view of a lower header of the outdoor
heat exchanger according to the embodiment of the present
invention;
[0051] FIG. 5 is a view illustrating a case in which a lowermost
introduction pipe is formed lower than a height of a connection
pipe;
[0052] FIG. 6 is an enlarged view of a lower head having a
temperature sensor according to another embodiment of the present
invention;
[0053] FIG. 7 is a block diagram of the air conditioner according
to the embodiment of the present invention;
[0054] FIG. 8 is a flowchart of a method of controlling the outdoor
heat exchanger according to a first embodiment of the present
invention; and
[0055] FIG. 9 is a flowchart of a method of controlling the outdoor
heat exchanger according to a second embodiment of the present
invention.
DETAILED DESCRIPTION
[0056] Reference will now be made in detail to the embodiments of
the present disclosure, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals may refer to
like or corresponding elements throughout the drawings and repeated
description thereof may be omitted. In addition, the components may
be described interchangeably as "modules" and "parts" in this
specification merely for the sake of convenience, and these terms
do not have distinct meanings or roles. Also, in the following
description, if it is considered that the specific description of
the related and well known functions or structures may obscure the
gist of the present invention, the specific description may be
omitted. Also, the description proposed herein is just a preferable
example for the purpose of illustration only, not intended to limit
the scope of the invention, so it should be understood that other
equivalents and modifications could be made thereto without
departing from the spirit and scope of the invention.
[0057] FIG. 2 is a view illustrating a structure of an air
conditioner according to an embodiment of the present invention,
and FIG. 3 is a view illustrating a main structure of an outdoor
heat exchanger according to the embodiment of the present
invention.
[0058] Referring to FIG. 2, the air conditioner 10 according to the
embodiment of the present invention includes an outdoor unit which
is disposed at an outdoor area, and an indoor unit which is
disposed at an indoor area. The indoor unit includes an indoor heat
exchanger which heat-exchanges with indoor air. FIG. 2 illustrates
a structure of the outdoor unit.
[0059] The air conditioner 10 includes a plurality of compressors
110 and 112, and oil separators 120 and 122 which are disposed at
outlet sides of the plurality of compressors 110 and 112 to
separate oil from a refrigerant discharged from the plurality of
compressors 110 and 112.
[0060] The plurality of compressors 110 and 112 include a first
compressor 110 and a second compressor 112 which are connected in
parallel with each other. A discharge temperature sensor 114 which
detects a temperature of the compressed refrigerant may be provided
at each of the outlet sides of the first and second compressors 110
and 112.
[0061] The oil separators 120 and 122 include a first oil separator
120 which is disposed at the outlet side of the first compressor
110 and the second oil separator 122 which is disposed at the
outlet side of the second compressor 112.
[0062] The air conditioner 10 includes a collection path 116, for
collecting oil, from the oil separators 120 and 122 to the
compressors 110 and 112. The collection path 116 extends from each
of the outlet sides of the first and second oil separators 120 and
122 and then is combined, and the combined path may be connected
with pipes located at inlet sides of the first and second
compressors 110 and 112.
[0063] A dryer 127 and a capillary 128 may be installed at the
collection path 116.
[0064] A high pressure sensor 125 which detects a high pressure of
the refrigerant discharged from the compressors 110 and 112, and a
flow switching part 130 which guides the refrigerant passing
through the high pressure sensor 125 toward an outdoor heat
exchanger 200 or the indoor unit are provided at outlet sides of
the oil separators 120 and 122. For example, the flow switching
part 130 may include a four-way valve.
[0065] When the air conditioner performs a cooling operation, the
refrigerant flows into the outdoor heat exchanger 200 from the flow
switching part 130. On the other hand, when the air conditioner
performs a heating operation, the refrigerant flows from the flow
switching part 130 toward an indoor heat exchanger of the indoor
unit (not shown).
[0066] When air conditioner performs the cooling operation, the
refrigerant condensed in the outdoor heat exchanger 200 passes
through a main expansion valve (an electronic expansion valve) 260.
At this time, the main expansion valve 260 is completely opened,
and thus does not perform a decompression action on the
refrigerant. That is, the main expansion valve 260 may be installed
at an outlet side of the outdoor heat exchanger 200 based on the
cooling operation.
[0067] The refrigerant passing through the main expansion valve 260
passes through a heat sinking panel 265. The heat sinking panel 265
may be provided at an electronic unit in which a heat generating
component is provided.
[0068] For example, the heat generating component may include a
power module (an intelligent power module (IPM)). It may be
understood that the IPM is a module in which a drive circuit and a
protection circuit having a self-protecting function of a power
device, such as MOSFET and IGBT, are installed.
[0069] The condensed refrigerant contacts the heat sinking panel
265, and cools the heat generating component.
[0070] The air conditioner 10 further includes a supercooling heat
exchanger 270 into which the refrigerant passing through the heat
sinking panel 265 is introduced, and a supercooling distributor 271
which is provided at an inlet side of the supercooling heat
exchanger 270 to branch the refrigerant. The supercooling heat
exchanger 270 serves as a middle heat exchanger which
heat-exchanges with a first refrigerant circulating in a system
after some (a second refrigerant) of the first refrigerant is
branched.
[0071] Here, the first refrigerant is a refrigerant which is
introduced into the supercooling heat exchanger 270 via the
supercooling distributor 271, and may be supercooled by the second
refrigerant. The second refrigerant may absorb heat from the first
refrigerant.
[0072] The air conditioner 10 includes a supercooling path 273
which is provided at an outlet side of the supercooling heat
exchanger 270 to allow the second refrigerant to be branched from
the first refrigerant. A supercooling expander 275 which
depressurizes the second refrigerant is provided at the
supercooling path 273. The supercooling expander 275 may include an
electronic expansion valve (EEV).
[0073] The second refrigerant in the supercooling path 273 may be
introduced into the supercooling heat exchanger 270, may
heat-exchange with the first refrigerant, and then may flow to an
inlet side of a gas-liquid separator 280. The air conditioner 10
further includes a super-cooled discharge temperature sensor 276
which detects a temperature of the second refrigerant passed
through the supercooling heat exchanger 270.
[0074] The gas-liquid separator 280 is a device which separates and
outputs a gaseous refrigerant before the refrigerant is introduced
into the compressors 110 and 112. The separated gaseous refrigerant
may be introduced into the compressors 110 and 112.
[0075] While a refrigeration cycle is driven, the evaporated
refrigerant may be introduced into the gas-liquid separator 280 via
the flow switching part 130. At this time, the evaporated
refrigerant is combined with the second refrigerant passing through
the supercooling heat exchanger 270, and then introduced into the
gas-liquid separator 280.
[0076] A suction temperature sensor 282 which detects a temperature
of the refrigerant to be suctioned into the compressors 110 and 112
may be provided at an inlet side of the gas-liquid separator
280.
[0077] Meanwhile, the first refrigerant passing through the
supercooling heat exchanger 270 may be introduced into the indoor
unit through an indoor unit connection pipe 279. The air
conditioner 10 further includes a liquid line temperature sensor
278 which is provided at the outlet side of the supercooling heat
exchanger 270 to detect a temperature of the first refrigerant
passed through the supercooling heat exchanger 270, i.e., a
temperature of the supercooled refrigerant.
[0078] Hereinafter, the outdoor heat exchanger 200 and a peripheral
structure thereof will be described.
[0079] The air conditioner 10 includes a first inlet/outlet pipe
201a which is connected from the flow switching part 130 to one
side of the outdoor heat exchanger 200, and a second inlet/outlet
pipe 201b which is connected from the other side of the outdoor
heat exchanger 200 to the main expansion valve 260.
[0080] For example, the first inlet/outlet pipe 201a may be
connected to an upper portion of a header 205, i.e., an upper
header 205a, and the second inlet/outlet pipe 201b may be connected
to a lower portion of the header 205, i.e., a lower header
205b.
[0081] When the air conditioner 10 performs the cooling operation,
the refrigerant is introduced into the outdoor heat exchanger 200
through the first inlet/outlet pipe 201a, and also discharged from
the outdoor heat exchanger 200 through the second inlet/outlet pipe
201b.
[0082] On the other hand, when the air conditioner 10 performs the
heating operation, the refrigerant is introduced into the outdoor
heat exchanger 200 through the second inlet/outlet pipe 201b, and
discharged from the outdoor heat exchanger 200 through the first
inlet/outlet pipe 201a.
[0083] The outdoor heat exchanger 200 includes a refrigerant pipe
202. For example, a plurality of refrigerant pipes 202 may be
provided to form two rows in a horizontal direction and a plurality
of columns in a vertical direction. The plurality of refrigerant
pipes 202 may be disposed to be spaced apart from each other.
[0084] The plurality of refrigerant pipes 202 may be bent and then
may extend longitudinally. For example, in FIG. 3, the plurality of
refrigerant pipes 202 may be formed to extend toward a rear of the
figure and then to extend again toward a front thereof. In this
case, the plurality of refrigerant pipes 202 may have a U
shape.
[0085] The outdoor heat exchanger 200 further includes a coupling
plate 203 which supports the refrigerant pipes 202. The coupling
plate 203 includes a first plate 203a which supports one side of
the refrigerant pipes 202 having a bent shape, and a second plate
203b which supports the other side thereof. The first and second
plates 203a and 203b extend vertically.
[0086] The outdoor heat exchanger 200 further includes a return
pipe 204 which is coupled to ends of the plurality of refrigerant
pipes 202 to guide the refrigerant flowing in one refrigerant pipe
202 to another refrigerant pipe 202. A plurality of return pipes
204 are provided, and coupled to one side of the first and second
plates 203a and 203b.
[0087] The outdoor heat exchanger 200 further includes the header
205 which forms a flow space of the refrigerant. The header 205 may
be configured to branch and introduce the refrigerant into the
plurality of refrigerant pipes 202 or to combine the refrigerant
heat-exchanged at the plurality of refrigerant pipes 202 according
to whether the air conditioner 10 performs the cooling operation or
the heating operation. The header 205 extends vertically
corresponding to an extension direction of the first plate
203a.
[0088] A plurality of refrigerant introduction pipes 232 extend
between the header 205 and the first plate 203a. The plurality of
refrigerant introduction pipes 232 extend from the header 205, and
are connected to the refrigerant pipes 202 which are supported by
the first plate 203a. And the plurality of refrigerant introduction
pipes 232 may be disposed to be vertically spaced apart from each
other.
[0089] When the air conditioner 10 performs the cooling operation,
the refrigerant in the header 205 may be introduced into the
refrigerant pipes 202 through the plurality of refrigerant
introduction pipes 232. On the other hand, when the air conditioner
10 performs the heating operation, the refrigerant in the
refrigerant pipes 202 may be introduced into the header 205 through
the refrigerant introduction pipes 232.
[0090] The air conditioner 10 further includes a plurality of
distributors 210 and 220 which branch and introduce the refrigerant
into the outdoor heat exchanger 200 based on the heating operation.
The plurality of distributors 210 and 220 include a first
distributor 210 and a second distributor 220.
[0091] The air conditioner 10 further includes a first distribution
pipe 211 and a second distribution pipe 221 which are branched from
the second inlet/outlet pipe 201b to the respective first and
second distributors 210 and 220. The first distribution pipe 211
and the second distribution pipe 221 may extend from a branch part
201c to the respective first and second distributors 210 and
220.
[0092] The air conditioner 10 further includes a first valve device
215 which is installed at the first distribution pipe 211 to
control an amount of the refrigerant flowing through the first
distribution pipe 211, and a second valve device 225 which is
installed at the second distribution pipe 221 to control an amount
of the refrigerant flowing through the second distribution pipe
221.
[0093] The first and second valve devices 215 and 225 may be an
electronic expansion valve of which an opening degree may be
controlled.
[0094] The air conditioner 10 further includes a plurality of
capillary tubes 207 which extend from the first and second
distributors 210 and 220 to the plurality of refrigerant pipes 202.
When the air conditioner 10 performs the heating operation, the
refrigerant is branched to the first distributor 210 and the second
distributor 220, and flows to the refrigerant pipes 202 through the
plurality of capillary tubes 207.
[0095] The air conditioner 10 further includes branch pipes 209
which connect the plurality of capillary tubes 207 with the
refrigerant pipes 202. The branch pipe 209 may branch the
refrigerant flowing through the capillary tube 207 into two
directions, i.e., toward one refrigerant pipe 202 and toward
another refrigerant pipe 202. For example, the branch pipe 209 may
be a Y-shaped branch pipe. A plurality of branch pipes 209 may be
provided corresponding to the number of the plurality of capillary
tubes 207.
[0096] When the air conditioner 10 performs the heating operation,
the refrigerant introduced into the refrigerant pipes 202 through
the plurality of capillary tubes 207 connected to the first
distributor 210 is heat-exchanged, and then introduced into the
upper header 205a of the header 205. The refrigerant introduced
into the refrigerant pipes 202 through the plurality of capillary
tubes 207 connected to the second distributor 220 is
heat-exchanged, and then introduced into the lower header 205b of
the header 205.
[0097] That is, the header 205 includes the upper header 205a which
is in communication with the first distributor 210, and the lower
header 205b which is in communication with the second distributor
220. In FIG. 3, an imaginary division line t1 which divides the
upper header 205a from the lower header 205b is indicated.
[0098] The air conditioner 10 further includes a check valve 240
which is installed between the upper header 205a and the lower
header 205b. The check valve 240 allows a flow of the refrigerant
from the lower header 205b to the upper header 205a, and restricts
the flow of the refrigerant from the upper header 205a to the lower
header 205b.
[0099] Therefore, when the air conditioner 10 performs the heating
operation, the refrigerant introduced into the refrigerant pipes
202 through the second distributor 220 may be heat-exchanged, may
be introduced into the lower header 205b, and may be guided to the
upper header 205a by the check valve 240. And the refrigerant
introduced into the refrigerant pipes 202 through the first
distributor 210 may be heat-exchanged, may be introduced into the
upper header 205a, may be combined with the refrigerant introduced
from the lower header 205b, and may flow to the first inlet/outlet
pipe 201a.
[0100] The air conditioner 10 further includes a connection pipe
230 which extends from one point of the first distribution pipe 211
to the lower header 205b. A third valve device 235 which controls a
flow rate of the refrigerant in the connection pipe 230 may be
installed at the connection pipe 230. For example, the third valve
device 235 may include a solenoid valve which may be controlled to
be switched on/off, or the electronic expansion valve of which the
opening degree is allowed.
[0101] When the air conditioner 10 performs the cooling operation,
the refrigerant flowing from the first distributor 210 to the first
distribution pipe 211 may be introduced into the lower header 205b
through the connection pipe 230.
[0102] The air conditioner 10 further includes a bypass pipe 250
which extends from a lower end of the header 205, i.e., a lower end
of the lower header 205b to the second inlet/outlet pipe 201b. When
the air conditioner 10 performs the cooling operation, the bypass
pipe 250 is formed to divert a liquid refrigerant accumulated at a
lower portion of the header 205 to the second inlet/outlet pipe
201b, i.e., the outlet side of the outdoor heat exchanger 200.
[0103] Hereinafter, a flow of the refrigerant in the air
conditioner 10 while the air conditioner 10 performs the heating
operation and the cooling operation will be described with
reference to FIGS. 2 and 3.
[0104] First, when the air conditioner 10 performs the heating
operation, oil is separated from the high temperature and high
pressure refrigerant compressed in the first and second compressors
110 and 112, while the refrigerant passes through the first and
second oil separators 120 and 122, and the separated oil is
returned to the first and second compressors 110 and 112 through
the collection path 116. And the refrigerant from which the oil is
separated flows toward the indoor unit via the flow switching part
130.
[0105] The refrigerant introduced into the indoor unit is condensed
in the indoor heat exchanger, and the condensed refrigerant is
introduced into the supercooling heat exchanger 270 through the
indoor unit connection pipe 279. At this time, some of the
refrigerant may be branched to the supercooling path 273, may be
depressurized in the supercooling expander 275, and then may be
introduced into the supercooling heat exchanger 270.
[0106] Therefore, the condensed refrigerant and the refrigerant
flowing through the supercooling path 273 heat-exchange with each
other, and thus the condensed refrigerant may be supercooled.
[0107] The supercooled refrigerant passed through the supercooling
heat exchanger 270 may cool the heat generating component of the
electronic unit, while passing through the heat sinking panel 265,
and may be depressurized in the main expansion valve 260.
[0108] The depressurized refrigerant may be branched from the
branch part 201c to the first and second distribution pipes 211 and
221, and then may be introduced into the first and second
distributors 210 and 220, respectively. At this time, the first and
second valve devices 215 and 225 may be opened by a predetermined
opening degree. For example, the first and second valve devices 215
and 225 may be completely opened.
[0109] The refrigerant flowing to the first distributor 210 is
introduced into the refrigerant pipes 202 through the plurality of
capillary tubes 207, heat-exchanged and then introduced into the
upper header 205a. The refrigerant flowing to the second
distributor 220 is introduced into the refrigerant pipes 202
through the plurality of capillary tubes 207, heat-exchanged and
then introduced into the lower header 205b. At this time, the
refrigerant may evaporate while being heat-exchanged.
[0110] The refrigerant introduced into the lower header 205b flows
to the upper header 205a, and is combined with the refrigerant
introduced into the upper header 205a. At this time, the
refrigerant in the lower header 205b may flow to the upper header
205a via the check valve 240 (referring to the dotted line
arrow).
[0111] The combined refrigerant may be discharged to the first
inlet/outlet pipe 201a connected to the upper header 205a, and may
be introduced into the gas-liquid separator 280 via the flow
switching part 130, and the separated gaseous refrigerant may be
suctioned into the first and second compressors 110 and 112. This
cycle may be repeated.
[0112] Like this, when the air conditioner 10 performs the heating
operation, the refrigerant may be introduced into the outdoor heat
exchanger 200 through the first and second distributors 210 and
220, and heat exchange may be performed using all of a path at a
side of the first distributor 210 and a path at a side of the
second distributor 220.
[0113] Therefore, the flow path of the refrigerant in the outdoor
heat exchanger 200 is reduced, but the number of paths branched to
the outdoor heat exchanger 200 is increased. Accordingly, the
pressure loss of the refrigerant may be reduced, and thus the
evaporating pressure drop may be prevented, and the evaporation
efficiency may be improved.
[0114] When the air conditioner 10 performs the cooling operation,
the oil is separated from the high temperature and high pressure
refrigerant compressed in the first and second compressors 110 and
112, while the refrigerant passes through the first and second oil
separators 120 and 122, and the separated oil is returned to the
first and second compressors 110 and 112 through the collection
path 116. And the refrigerant from which the oil is separated flows
toward the first inlet/outlet pipe 201a via the flow switching part
130, and is introduced into the header 205 of the outdoor heat
exchanger 200.
[0115] The refrigerant introduced into the header 205 is located at
the upper header 205a, and restricted from being introduced into
the lower header 205b by the check valve 240.
[0116] The refrigerant in the upper header 205a is introduced into
the refrigerant pipes 202 fixed to the first plate 203a through the
plurality of refrigerant introduction pipes 232. The refrigerant in
the refrigerant pipes 202 is heat-exchanged, and then flows to the
plurality of capillary tubes 207 through the branch pipes 209. At
this time, the refrigerant may be primarily condensed while being
heat-exchanged.
[0117] The refrigerant in the plurality of capillary tubes 207 is
combined in the first distributor 210, and introduced into the
lower header 205b through the first distribution pipe 211 and the
connection pipe 230. At this time, the first valve device 215 is
closed, and thus the refrigerant is restricted from flowing to the
branch part 201c. And the third valve device 235 is turned on, or
opened by a predetermined opening degree, and allows the
refrigerant to flow to the connection pipe 230.
[0118] The refrigerant introduced into the lower header 205b is
introduced into the plurality of refrigerant pipes 202 fixed to the
first plate 203a through the plurality of refrigerant introduction
pipes 232. And the refrigerant may be secondarily condensed while
flowing through the plurality of refrigerant pipes 202.
[0119] The secondarily condensed refrigerant is introduced into the
second distributor 220 through the branch pipes 209 and the
plurality of capillary tubes 207. The refrigerant in the second
distributor 220 flows through the second inlet/outlet pipe 201b via
the second distribution pipe 221 and the branch part 201c, and is
discharged from the outdoor heat exchanger 200.
[0120] The refrigerant discharged from the outdoor heat exchanger
200 may flow toward the indoor unit via the heat sinking panel 265
and the supercooling heat exchanger 270. The refrigerant may be
expanded and evaporated in the indoor unit, and then may be
suctioned into the first and second compressors 110 and 120 via the
flow switching part 130 and the gas-liquid separator 280. This
cycle may be repeated.
[0121] Like this, when the air conditioner 10 performs the cooling
operation, the refrigerant introduced into the outdoor heat
exchanger 200 is primarily condensed in the refrigerant pipes 202
connected to a side of the upper header 205a, and secondarily
condensed in the refrigerant pipes 202 connected to a side of the
lower header 205b. Therefore, the flow path of the refrigerant in
the outdoor heat exchanger 200 is increased, but the number of
paths branched to the outdoor heat exchanger 200 is reduced.
Accordingly, the flow speed of the refrigerant is increased, and
the condensing pressure is reduced, and thus the condensation
efficiency may be improved.
[0122] Meanwhile, the lower header 205b may be filled with the
liquid refrigerant. Specifically, the refrigerant is primarily
condensed while flowing through the refrigerant pipes 202 connected
to the upper header 205a, and thus may have two phases. Therefore,
the refrigerant introduced into the lower header 205b through the
connection pipe 230 may be in a state in which a gas phase and a
liquid phase are included.
[0123] Since the liquid refrigerant has a greater specific gravity
than the gaseous refrigerant, the liquid refrigerant may fill a
lower side of the lower header 205b. It may be understood that the
liquid refrigerant is a refrigerant which is completely condensed
and which does not need the heat exchange any more. Therefore, when
the liquid refrigerant is introduced into the refrigerant pipes 202
and then heat-exchanged again, heat exchange performance of the
heat exchanger may be degraded, and the pressure loss due to the
liquid refrigerant may occur.
[0124] Therefore, the embodiment is characterized by providing the
bypass pipe 250 which diverts the liquid refrigerant to the outlet
side of the outdoor heat exchanger 200. The bypass pipe 250 extends
from the lower header 205b to the second inlet/outlet pipe 201b,
and discharges the refrigerant accumulated in the lower header 205b
to the second inlet/outlet pipe 201b during the cooling
operation.
[0125] Hereinafter, a structure of the lower header 205b will be
described in detail with reference to FIG. 4.
[0126] FIG. 4 is an enlarged view of the lower header 205b of the
outdoor heat exchanger according to the embodiment of the present
invention.
[0127] Referring to FIG. 4, the outdoor heat exchanger 200
according to the embodiment of the present invention includes the
bypass pipe 250 which diverts the liquid refrigerant in the header
205 to the outlet side of the outdoor heat exchanger 200.
[0128] The bypass pipe 250 extends from a lower portion of the
lower header 205b of the header 205 toward the second inlet/outlet
pipe 201b.
[0129] The outdoor heat exchanger 200 according to the embodiment
of the present invention includes the plurality of refrigerant
introduction pipes 232 which extend from the lower header 205b to
the plurality of refrigerant pipes 202. The plurality of
refrigerant introduction pipes 232 include a lowermost introduction
pipe 232a, and a plurality of upper introduction pipes 232b which
are disposed above the lowermost introduction pipe 232a. A height
H2 of the lowermost introduction pipe 232a may be formed higher
than a height H1 of the connection pipe 230 which extends from one
point of the first distribution pipe 211 to the lower header 205b.
Here, it may be understood that each of the heights H2 and H1 is a
distance from a reference line t0, and, for example, the reference
line t0 may be a base which forms a bottom of the outdoor unit, or
a ground surface.
[0130] Like this, since the height H1 of the connection pipe 230 is
formed lower than the height H2 of the lowermost introduction pipe
232a, the liquid refrigerant in the lower header 205b may be
prevented from being introduced into the lowermost introduction
pipe 232a.
[0131] FIG. 5 is a view illustrating a case in which the lowermost
introduction pipe is formed lower than the height of the connection
pipe.
[0132] Hereinafter, an effect of the outdoor heat exchanger in
which the height of the connection pipe 230 is designed lower than
the height of the lowermost introduction pipe 232a will be
described with reference to FIGS. 4 and 5.
[0133] As described above, the refrigerant introduced into the
lower header 205b through the connection pipe 230 simultaneously
contains the gas phase and the liquid phase refrigerant. However,
since the liquid refrigerant has a greater specific gravity than
the gaseous refrigerant, the liquid refrigerant fills the lower
side of the lower header 205b, and the gaseous refrigerant fills
above the liquid refrigerant. Therefore, a part of the plurality of
refrigerant pipes which are in communication with the lower header
205b are blocked by the liquid refrigerant.
[0134] As illustrated in FIG. 5, since the refrigerant introduction
pipes 232 disposed at an area A in which a liquid refrigerant L is
located are blocked by the liquid refrigerant L, the gaseous
refrigerant to be secondarily condensed may flow through only the
refrigerant introduction pipes 232 disposed at an area B.
Therefore, the gaseous refrigerant may not smoothly flow to the
plurality of refrigerant introduction pipes 232, and thus the
condensation efficiency and the heat exchange performance of the
outdoor heat exchanger are degraded.
[0135] However, in the embodiment shown in FIG. 4, since the height
H2 of the lowermost introduction pipe 232a is formed higher than
the height H1 of the connection pipe 230, the plurality of
refrigerant introduction pipes 232 are prevented from being blocked
by the liquid refrigerant L, and thus the condensation efficiency
and the heat exchange performance of the outdoor heat exchanger 200
may be improved.
[0136] Also, since the bypass pipe 250 is provided, the liquid
refrigerant in the lower header 205b may be diverted to the outlet
side of the outdoor heat exchanger 200, and thus the heat exchange
performance of the outdoor heat exchanger 200 may be improved.
[0137] In other words, since the liquid refrigerant filling the
lower side of the lower header 205b is a refrigerant which does not
need to heat exchange, the liquid refrigerant may be diverted to
the outlet side of the outdoor heat exchanger 200 through the
bypass pipe 250, and the gaseous refrigerant which needs to heat
exchange may be effectively heat-exchanged by the openings of all
the plurality of refrigerant introduction pipes 232.
[0138] And since the bypass pipe 250 extends downward from a lower
surface of the lower header 205b, the gaseous refrigerant in the
lower header 205b may be prevented from being discharged through
the bypass pipe 250 by a pressure difference between the gaseous
refrigerant and the liquid refrigerant.
[0139] Meanwhile, the air conditioner 10 further includes a bypass
pipe valve 252 which is installed at the bypass pipe 250 to control
an amount of the refrigerant flowing through the bypass pipe
250.
[0140] The bypass pipe valve 252 may include an electronic
expansion valve of which an opening degree may be controlled.
[0141] When the bypass pipe valve 252 is opened, the liquid
refrigerant filling the lower side of the lower header 205b is
diverted to the outlet side of the outdoor heat exchanger 200, and
when the bypass pipe valve 252 is closed, the liquid refrigerant
filling the lower side of the lower header 205b is prevented from
flowing to the outlet side of the outdoor heat exchanger 200.
[0142] As described above, the refrigerant introduced into the
lower header 205b through the connection pipe 230 is in the state
in which the gas phase and the liquid phase are included.
Therefore, since the liquid refrigerant has the greater specific
gravity than the gaseous refrigerant, the liquid refrigerant may
fill the lower side of the lower header 205b. Since the liquid
refrigerant is a refrigerant which is completely condensed and
which does not need to heat exchange any more, the liquid
refrigerant may be diverted to the outlet side of the outdoor heat
exchanger 200 through the bypass pipe 250, and thus the heat
exchange performance of the outdoor heat exchanger 200 may be
enhanced.
[0143] Also, since a flow of the liquid refrigerant to the outlet
side of the outdoor heat exchanger 200 may be controlled by
controlling the opening degree of the bypass pipe valve 252, the
liquid refrigerant may be prevented from accumulating at one side
due to force of gravity, and the pressure loss of the refrigerant
may be minimized, and thus efficiency of the cooling operation may
be maximized.
[0144] Meanwhile, a detector 30 (see, for example, FIG. 7) which
detects the amount of the refrigerant may be provided at a
refrigerant flowing space of the header 205. Specifically, the
detector 30 is disposed at a path in the lower header 205b in which
the primarily condensed refrigerant flows.
[0145] The detector 30 which detects an amount of the liquid
refrigerant may be provided at the lower header 205b. Hereinafter,
a method of detecting the amount of the liquid refrigerant using
the detector 30 will be described.
[0146] FIG. 6 is an enlarged view of the lower head having a
temperature sensor according to another embodiment of the present
invention.
[0147] FIG. 4 illustrates the lower header 205b in which a liquid
level sensor 290 is provided, and FIG. 6 illustrates the lower
header 205b in which a temperature sensor 300 is provided. The
liquid level sensor 290 and the temperature sensor 300 are an
example for detecting the amount of the liquid refrigerant
introduced into the lower header 205b. However, the present
invention is not limited thereto, and various structures for
detecting the amount of the liquid refrigerant may be provided.
Also, both of the liquid level sensor 290 and the temperature
sensor 300 may be disposed at the lower header 205b.
[0148] Referring to FIG. 4, the detector 30 may include the liquid
level sensor 290 which is provided at an inside of the lower header
205b to detect a level of the liquid refrigerant introduced into
the lower header 205b.
[0149] Specifically, the liquid level sensor 290 may be provided at
a refrigerant path of the lower header 205b to be in contact with
the liquid refrigerant, and thus to detect a liquid level in the
lower header 205b. That is, when the liquid level sensor 290 is in
contact with the liquid refrigerant, it indicates that the liquid
refrigerant is introduced into the lower header 205b to a height at
which the liquid level sensor is installed, and thus the amount of
the liquid refrigerant may be detected by calculating the height at
which the liquid level sensor is installed in the lower header
205b.
[0150] For example, the liquid level sensor 290 may be disposed
between the bypass pipe 250 and the connection pipe 230. Since the
plurality of refrigerant introduction pipes 232 to which the
refrigerant in the lower header 205b flows so as to be secondarily
condensed are blocked by an increase in the amount of the liquid
refrigerant, the gaseous refrigerant which is required to be
condensed may not be introduced into the refrigerant pipes 202.
Therefore, the liquid level sensor 290 is installed between the
connection pipe 230 and the bypass pipe 250, and when the liquid
refrigerant is at an amount that is detected by the liquid level
sensor 290, the bypass pipe valve 252 may be opened, and thus the
liquid refrigerant may be discharged to an outside of the outdoor
heat exchanger 200. Due to the discharge of the liquid refrigerant,
the gaseous refrigerant is introduced into the refrigerant pipes
202, and a secondary condensing process is performed.
[0151] Meanwhile, a plurality of liquid level sensors 290 may be
disposed. When the plurality of liquid level sensors 290 are
provided, the liquid level sensors 290 may include a first liquid
level sensor 292 which is disposed at the lowermost side of the
lower header 205b, and a plurality of liquid level sensors 293
which are disposed above the first liquid level sensor 292. That
is, the liquid level sensors 290 may be provided at the inside of
the lower header 205b to be spaced upward from each other at
regular intervals from the lower surface of the lower header 205b.
In this case, there is an advantage that the amount of the liquid
refrigerant introduced into the lower header 205b may be detected
more specifically.
[0152] Referring to FIG. 6, the detector 30 may include the
temperature sensor 300 which is provided at the inside of the lower
header 205b to detect a temperature of the liquid refrigerant
introduced into the lower header 205b.
[0153] The temperature sensor 300 may include a first temperature
sensor 302 which is installed adjacent to the lower surface of the
lower header 205b, and a second temperature sensor 304 which is
installed adjacent to an upper surface of the lower header
205b.
[0154] Specifically, the first temperature sensor 302 is provided
at the lower portion of the lower header 205b to be relatively
close to the bypass pipe 250, and the second temperature sensor 304
is provided at the upper portion of the lower header 205b to be
relatively close to the check valve 240. Therefore, the first
temperature sensor 302 may be referred to as a lower sensor 302,
and the second temperature sensor 304 may be referred to as an
upper sensor 304.
[0155] The positions of the first and second temperature sensors
302 and 304 are just an example, and may be variously installed to
have different installation heights in the lower header 205b.
[0156] A method of detecting the amount of the liquid refrigerant
introduced into the lower header 205b using the temperature sensor
300 will be described.
[0157] When the bypass pipe valve 252 is closed, and thus the lower
header 205b is filled from a lower end thereof with the liquid
refrigerant, the first temperature sensor 302 adjacent to the lower
end thereof detects the temperature of the liquid refrigerant.
However, since the gaseous refrigerant is located at the upper
portion of the lower header 205b which is not filled with the
liquid refrigerant, and the gaseous refrigerant has a relatively
higher temperature than the liquid refrigerant, the first
temperature sensor 302 detects a relatively lower temperature than
the second temperature sensor 304.
[0158] When the liquid refrigerant is continuously introduced into
the lower header 205b, the liquid refrigerant fills the lower
header 205b to an installation height of the second temperature
sensor 304. Therefore, the second temperature sensor 304 also
detects the temperature of the liquid refrigerant which is
approximately similar to a value of the temperature detected by the
first temperature sensor 302. Accordingly, it may be detected that
the liquid refrigerant fills the lower header 205b to the
installation height of the second temperature sensor 304.
[0159] Meanwhile, a plurality of temperature sensors 300 which are
more than two may be provided. When more than two temperature
sensors 300 are provided, the temperature sensors 300 may be
provided at the inside of the lower header 205b to be spaced upward
from each other at regular intervals from the lower surface of the
lower header 205b. In this case, there is an advantage that the
amount of the liquid refrigerant introduced into the lower header
205b may be detected more specifically.
[0160] Also, there is another advantage in that it is possible to
grasp a supercooled degree of the liquid refrigerant and the
gaseous refrigerant through the temperature sensor 300 and thus,
determine a cooled state.
[0161] FIG. 7 is a block diagram of the air conditioner according
to the embodiment of the present invention.
[0162] Referring to FIG. 7, the air conditioner 10 may include a
controller 20, a detector 30, a memory 40 and a valve driver 50.
Elements illustrated in FIG. 7 are not essential to realize the air
conditioner, and thus the air conditioner 10 described in the
specification may have more elements or less elements than the
above-described ones.
[0163] More specifically, the detector 30 among the elements is an
element which detects the amount of the refrigerant introduced into
the lower header 205b, as described above, and may include the
liquid level sensor 290 and/or the temperature sensor 300.
[0164] Various set values are inputted to the memory 40. For
example, the set values may include an opening degree of the bypass
pipe valve 252, an installation height of the liquid level sensor
290, a set range for a difference value of the temperature sensor
300 and so on.
[0165] The valve driver 50 receives a command from the controller
based on information about the liquid refrigerant detected by the
detector 30, and controls the opening degree of the bypass pipe
valve 252. Specifically, the valve driver 50 includes a first valve
driver 51 which controls the opening degree of the first valve
device 215, a second valve driver 52 which controls the opening
degree of the second valve device 225, a third valve driver 53
which controls the opening degree of the third valve device 235,
and a fourth valve driver 54 which controls the opening degree of
the bypass pipe valve 252.
[0166] Typically, the controller 20 controls an overall operation
of the air conditioner 10. The controller 20 serves to process a
signal and information input or output through the above-described
elements, or to drive the elements. The controller 20 may be a
microprocessor, a digital signal processor (DSP), integrated
circuit, or the like.
[0167] Hereinafter, a method of controlling the outdoor heat
exchanger 200 will be described using an example in which the air
conditioner 10 performs the cooling operation.
[0168] FIG. 8 is a flowchart of the method of controlling the
outdoor heat exchanger according to a first embodiment of the
present invention.
[0169] Referring to FIG. 8, the air conditioner 10 performs the
cooling operation (S100). The refrigerant introduced into the upper
header 205a is introduced into the lower header 205b via the
refrigerant pipe 202, the branch pipe 209, the first distributor
210 and the connection pipe 230.
[0170] Therefore, in the lower header 205b, there is the
refrigerant having the two phases of the gaseous refrigerant and
the liquid refrigerant which are mixed. However, since the liquid
refrigerant has the greater specific gravity than the gaseous
refrigerant, the liquid refrigerant fills the lower side of the
lower header 205b. At this time, the liquid level sensor 290
detects the liquid refrigerant filling the lower header 205b
(S110).
[0171] And whether the level of the liquid refrigerant is increased
to an installation height of the liquid level sensor 290 in the
lower header 205b is detected (S120). When the level of the liquid
refrigerant is lower than the liquid level sensor 290, the bypass
pipe valve 252 is closed (S140), and thus the lower header 205b is
continuously filled with the liquid refrigerant.
[0172] However, when the level of the liquid refrigerant is
increased to the installation height of the liquid level sensor
290, the controller 20 sends a signal to the valve driver 50, and
thus the fourth valve driver 54 opens the bypass pipe valve 252
(S130). Therefore, the liquid refrigerant introduced into the lower
header 205b is diverted to the outlet side of the outdoor heat
exchanger 200 through the bypass pipe 250, and thus the heat
exchange performance in the outdoor heat exchanger 200 may be
improved. Meanwhile, the gaseous refrigerant contained in the
introduced refrigerant is introduced into the plurality of
refrigerant introduction pipes 232, and then secondarily
condensed.
[0173] FIG. 9 is a flowchart of a method of controlling the outdoor
heat exchanger according to a second embodiment of the present
invention.
[0174] Referring to FIG. 9, the air conditioner 10 performs the
cooling operation (S200). The refrigerant introduced into the upper
header 205a is introduced into the lower header 205b via the
refrigerant pipe 202, the branch pipe 209, the first distributor
210 and the connection pipe 230.
[0175] The temperature sensor 300 detects the temperature of the
introduced refrigerant (S210).
[0176] The plurality of temperature sensors 300 are provided to
have heights different from each other. Since the gaseous
refrigerant contained in the refrigerant having the two phases has
a different temperature from the liquid refrigerant, and the lower
side of the lower header 205b is filled with the liquid
refrigerant, a temperature detected at the lower surface of the
lower header 205b is lower at the beginning.
[0177] That is, the first temperature sensor 302 among the
plurality of temperature sensors is disposed at the lower side of
the lower header 205b first detects the temperature of the liquid
refrigerant. The second temperature sensor 304 is disposed at the
upper side of the lower header 205b. When the lower header 205b is
filled with the liquid refrigerant to the installation height of
the second temperature sensor 304, the second temperature sensor
304 detects the temperature of the liquid refrigerant.
[0178] In other words, in the beginning, the temperature detected
by the first temperature sensor 302 which detects the temperature
of the liquid refrigerant is lower than that detected by the second
temperature sensor 304 which detects the temperature of the gaseous
refrigerant. When the liquid refrigerant fills continuously, and
thus the second temperature sensor 304 detects the temperature of
the liquid refrigerant, the first and second temperature sensors
302 and 304 have the similar temperature values.
[0179] The controller 20 compares the first temperature sensor 302
with the second temperature sensor 304 (S220). When a difference
between the temperature values detected by the first and second
temperature sensors 302 and 304 deviates from a set range in the
memory 40, it indicates that the liquid refrigerant has not filled
to the installation height of the second temperature sensor 304,
and thus the controller 20 controls the valve driver 50 so that the
fourth valve driver 54 has the bypass pipe valve 252 closed (S240).
When the bypass pipe valve 252 is closed, the lower header 205b is
continuously filled with the liquid refrigerant.
[0180] However, when the difference between the temperature values
detected by the first and second temperature sensors 302 and 304 is
within the set range, it indicates that the liquid refrigerant has
filled to the installation height of the second temperature sensor
304, and thus the controller 20 sends a command to the valve driver
50 to open the bypass pipe valve 252 (S230). Therefore, the liquid
refrigerant introduced into the lower header 205b is diverted to
the outlet side of the outdoor heat exchanger 200 through the
bypass pipe 250, and thus the heat exchange performance of the
outdoor heat exchanger 200 may be improved.
[0181] The air conditioner and the method of controlling the same
have the following effects.
[0182] During the cooling operation and the heating operation of
the air conditioner, the number of the paths through which the
refrigerant passes through the outdoor heat exchanger and the
length of each of the paths are formed differently, and thus the
heat exchange efficiency in the outdoor heat exchanger can be
improved.
[0183] Specifically, when the air conditioner performs the heating
operation, the number of the paths through which the refrigerant is
introduced into the outdoor heat exchanger can be reduced, and the
length of each of the paths can be increased. Therefore, the flow
speed of the refrigerant is increased, and the condensing pressure
is reduced, and thus the condensation efficiency can be
improved.
[0184] Also, since there is provided the bypass pipe through which
the liquid refrigerant in the lower side of the header of the
outdoor heat exchanger is diverted to the outlet side of the
outdoor heat exchanger, the liquid refrigerant can be prevented
from accumulating at the lower side of the header during the
cooling operation.
[0185] Eventually, since the liquid refrigerant which is already
condensed, and thus does not need to heat exchange can be
discharged from the outdoor heat exchanger, the heat exchange
performance (the condensation performance) of the outdoor heat
exchanger can be improved, and the pressure loss due to the liquid
refrigerant can be prevented.
[0186] Also, there is an advantage that it is possible to detect
the state of the amount of the liquid refrigerant and the gaseous
refrigerant through the detecting sensor provided at the lower
header.
[0187] Also, there is another advantage that the cooling efficiency
and the heat exchange efficiency of the heat exchanger can be
enhanced by controlling the opening degree of the valve provided at
the bypass pipe according to detected information.
[0188] 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.
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