U.S. patent application number 10/911696 was filed with the patent office on 2005-07-28 for air conditioner.
This patent application is currently assigned to LG ELECTRONICS INC.. Invention is credited to Choi, Sung Oh, Kim, Sung Chun, Park, Jong Han, Yoon, Seok Ho.
Application Number | 20050160763 10/911696 |
Document ID | / |
Family ID | 34651516 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050160763 |
Kind Code |
A1 |
Choi, Sung Oh ; et
al. |
July 28, 2005 |
Air conditioner
Abstract
Air conditioner including an outdoor unit installed in outdoor
having a compressor, an outdoor heat exchanger, an indoor unit
installed in indoor having an indoor heat exchanger, a distributor
for guiding refrigerant from the outdoor unit to the indoor unit
proper to an operation condition, and refrigerant passed through
the indoor unit to the outdoor unit, again, and a subcooling device
for subcooling the refrigerant passed through a heat exchange
process at the outdoor heat exchanger under an isobaric condition,
and guiding the subcooled refrigerant to the distributor, thereby
improving an air conditioning capability.
Inventors: |
Choi, Sung Oh;
(Gwangmyeong-si, KR) ; Park, Jong Han;
(Gwangmyeong-si, KR) ; Yoon, Seok Ho; (Seoul,
KR) ; Kim, Sung Chun; (Seoul, KR) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
34651516 |
Appl. No.: |
10/911696 |
Filed: |
August 5, 2004 |
Current U.S.
Class: |
62/513 |
Current CPC
Class: |
F25B 2313/007 20130101;
F25B 2313/02334 20130101; F25B 2313/0253 20130101; F25B 2400/13
20130101; F25B 2313/0231 20130101; F25B 13/00 20130101; F25B
2313/02331 20130101; F25B 40/02 20130101 |
Class at
Publication: |
062/513 |
International
Class: |
F25B 041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2004 |
KR |
P2004-5045 |
Claims
What is claimed is:
1. An air conditioner comprising: an outdoor unit installed in
outdoor having a compressor, an outdoor heat exchanger; an indoor
unit installed in indoor having an indoor heat exchanger; a
distributor for guiding refrigerant from the outdoor unit to the
indoor unit proper to an operation condition, and refrigerant
passed through the indoor unit to the outdoor unit, again; and a
subcooling device for subcooling the refrigerant passed through a
heat exchange process at the outdoor heat exchanger under an
isobaric condition, and guiding the subcooled refrigerant to the
distributor.
2. The air conditioner as claimed in claim 1, wherein the
subcooling device makes a portion of the refrigerant passed through
the heat exchange process at the outdoor heat exchanger to expand,
and the expanded portion of the refrigerant to heat exchange with
rest unexpanded refrigerant.
3. The air conditioner as claimed in claim 1, wherein the
subcooling device includes; a subcooling heat exchanger for making
an expanded portion of the refrigerant to heat exchange with rest
unexpanded refrigerant, a first connection pipeline having an
expansion device for expanding a portion of the refrigerant passed
through a heat exchange process at the outdoor heat exchanger, for
guiding expanded refrigerant to the subcooling heat exchanger, a
second connection pipeline for guiding unexpanded refrigerant to
the subcooling heat exchanger, a third connection pipeline for
guiding unexpanded refrigerant passed through the subcooling heat
exchanger to the distributor, and a fourth connection pipeline for
guiding the expanded refrigerant passed through the subcooling heat
exchanger to the refrigerant pipeline connected to a suction end of
the compressor.
4. The air conditioner as claimed in claim 3, wherein the
subcooling heat exchanger includes; a first flow pipeline having
one end connected to the second connection pipeline, and the other
end connected to the third connection pipeline for flow of
unexpanded refrigerant, and a second flow pipeline having one end
connected to the first connection pipeline, and the other end
connected to the fourth connection pipeline for making heat
exchange with the first flow pipeline, and flow of the expanded
refrigerant.
5. The air conditioner as claimed in claim 4, wherein the
subcooling heat exchanger has a double pipe structure.
6. The air conditioner as claimed in claim 5, wherein the second
flow pipeline is provided in an inside of the first flow pipeline
in a longitudinal direction.
7. The air conditioner as claimed in claim 6, wherein the
refrigerant flowing through the second flow pipeline has a flow
direction opposite to a flow direction of the refrigerant flowing
through the first flow pipeline.
8. The air conditioner as claimed in claim 6, wherein the
refrigerant flowing through the second flow pipeline has a flow
direction the same with a flow direction of the refrigerant flowing
through the first flow pipeline.
9. The air conditioner as claimed in claim 5, wherein the first
flow pipeline is provided inside of the second flow pipeline in a
longitudinal direction.
10. The air conditioner as claimed in claim 5, wherein the
subcooling heat exchanger has a length of 1 m.about.2.5 m.
11. The air conditioner as claimed in claim 5, wherein the
subcooling heat exchanger further includes a heat exchange part on
an inside wall for making a heat exchange area larger.
12. The air conditioner as claimed in claim 11, wherein the heat
exchange part is projected inward from an inside wall of the inner
flow pipe.
13. The air conditioner as claimed in claim 12, wherein the heat
exchange part is provided on an inside wall of the inner flow pipe
in a circumferential direction.
14. The air conditioner as claimed in claim 12, wherein the heat
exchange part is provided on an inside wall of the inner flow pipe
in a flow direction of the refrigerant.
15. The air conditioner as claimed in claim 12, wherein the heat
exchange part is provided on an inside wall of the inner flow pipe
in a helix.
16. The air conditioner as claimed in claim 3, wherein the
expansion device is an electronic expansion valve.
17. The air conditioner as claimed in claim 3, further comprising
an accumulator on a refrigerant pipeline connected to the suction
end of the compressor for separating gaseous refrigerant from
liquid refrigerant.
18. The air conditioner as claimed in claim 12, wherein the fourth
connection pipeline is connected to a refrigerant pipeline
connected to a refrigerant inlet to the accumulator.
19. The air conditioner as claimed in claim 1, wherein the
subcooling device is provided to a predetermined position of an
inside of the outdoor unit.
20. The air conditioner as claimed in claim 1, wherein the outdoor
unit further includes a switching device for switching a flow
direction of the refrigerant from the compressor to the outdoor
heat exchanger or the distributor selectively proper to an
operation condition.
Description
[0001] This application claims the benefit of the Korean
Application No. P2004-0005045 filed on Jan. 27, 2004, which is
hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to air conditioners, and more
particularly, to an air conditioner of an improved air conditioning
capability.
[0004] 2. Background of the Related Art
[0005] In general, the air conditioner cools or heats a room space,
such as a residential space, a restaurant, a library, or an office,
is provided with a compressor, and a heat exchanger to circulate
refrigerant for cooling/heating the room space.
[0006] The air conditioner is developed to a multi-type air
conditioner which can cools and heats at the same time enabling to
cool or heat all rooms in the same operation mode, for maintaining
a more comfortable room environment without being influenced from
external weather or environment.
[0007] Such a related art multi-type air conditioner has a
plurality of indoor units each installed in each room and connected
to one outdoor unit, for cooling or heating all rooms in a cooling
or heating mode.
[0008] However, in a case the related art multi-type air
conditioner is applied to one, such as a high building having a
complicate structure, and varieties of positions and purposes of
rooms therein, pipelines from the outdoor unit to the indoor units
become lengthy, to cause a pressure drop of the refrigerant
introduced into the indoor unit, and drop of an air conditioning
efficiency of the multi-type air conditioner.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is directed to an air
conditioner that substantially obviates one or more of the problems
due to limitations and disadvantages of the related art.
[0010] An object of the present invention is to provide an air
conditioner having an improved air conditioning capability.
[0011] Other object of the present invention is to provide an air
conditioner which can minimize a pressure loss of refrigerant
flowing in a refrigerant pipe caused by lengthy refrigerant
pipeline for guiding the refrigerant, and secure a subcooling state
of refrigerant introduced into an expansion device.
[0012] Additional features and advantages of the invention will be
set forth in the description which follows, and in part will be
apparent to those having ordinary skill in the art upon examination
of the following or may be learned from practice of the invention.
The objectives and other advantages of the invention will be
realized and attained by the structure particularly pointed out in
the written description and claims hereof as well as the appended
drawings.
[0013] To achieve these objects and other advantages and in
accordance with the purpose of the present invention, as embodied
and broadly described herein, the air conditioner includes an
outdoor unit installed in outdoor having a compressor, an outdoor
heat exchanger, an indoor unit installed in indoor having an indoor
heat exchanger, a distributor for guiding refrigerant from the
outdoor unit to the indoor unit proper to an operation condition,
and refrigerant passed through the indoor unit to the outdoor unit,
again, and a subcooling device for subcooling the refrigerant
passed through a heat exchange process at the outdoor heat
exchanger under an isobaric condition, and guiding the subcooled
refrigerant to the distributor.
[0014] The subcooling device makes a portion of the refrigerant
passed through the heat exchange process at the outdoor heat
exchanger to expand, and the expanded portion of the refrigerant to
heat exchange with rest unexpanded refrigerant.
[0015] The subcooling device includes a subcooling heat exchanger
for making an expanded portion of the refrigerant to heat exchange
with rest unexpanded refrigerant, a first connection pipeline
having an expansion device for expanding a portion of the
refrigerant passed through a heat exchange process at the outdoor
heat exchanger, for guiding expanded refrigerant to the subcooling
heat exchanger, a second connection pipeline for guiding unexpanded
refrigerant to the subcooling heat exchanger, a third connection
pipeline for guiding unexpanded refrigerant passed through the
subcooling heat exchanger to the distributor, and a fourth
connection pipeline for guiding the expanded refrigerant passed
through the subcooling heat exchanger to the refrigerant pipeline
connected to a suction end of the compressor.
[0016] The subcooling heat exchanger includes a first flow pipeline
having one end connected to the second connection pipeline, and the
other end connected to the third connection pipeline for flow of
unexpanded refrigerant, and a second flow pipeline having one end
connected to the first connection pipeline, and the other end
connected to the fourth connection pipeline for making heat
exchange with the first flow pipeline, and flow of the expanded
refrigerant.
[0017] The subcooling heat exchanger has a double pipe structure.
The second flow pipeline is provided in an inside of the first flow
pipeline in a longitudinal direction.
[0018] The refrigerant flowing through the second flow pipeline has
a flow direction opposite to a flow direction of the refrigerant
flowing through the first flow pipeline, or a flow direction the
same with a flow direction of the refrigerant flowing through the
first flow pipeline.
[0019] The first flow pipeline is provided inside of the second
flow pipeline in a longitudinal direction.
[0020] The subcooling heat exchanger has a length of 1 m.about.2.5
m.
[0021] The subcooling heat exchanger further includes a heat
exchange part on an inside wall for making a heat exchange area
larger.
[0022] The heat exchange part is projected inward from an inside
wall of the inner flow pipe. In more detail, the heat exchange part
is provided on an inside wall of the inner flow pipe in a
circumferential direction.
[0023] The heat exchange part is provided on an inside wall of the
inner flow pipe in a longitudinal direction, or in a helix.
[0024] The expansion device is an electronic expansion valve.
[0025] The air conditioner further includes an accumulator on a
refrigerant pipeline connected to the suction end of the compressor
for separating gaseous refrigerant from liquid refrigerant.
[0026] The fourth connection pipeline is connected to a refrigerant
pipeline connected to a refrigerant inlet to the accumulator.
[0027] The subcooling device is provided to a predetermined
position of an inside of the outdoor unit.
[0028] The outdoor unit further includes a switching device for
switching a flow direction of the refrigerant from the compressor
to the outdoor heat exchanger or the distributor selectively proper
to an operation condition.
[0029] The present invention provides a multi-type air conditioner
which enables some of rooms operative in a cooling mode, while
other rooms are operative in a heating mode according to room
environments, improves degrees of freedom of installation of the
multi-type air conditioner, and maintains a subcooling state of the
refrigerant.
[0030] It is to be understood that both the foregoing description
and the following detailed description of the present invention are
exemplary and explanatory and are intended to provide further
explanation of the invention claimed.
BRIEF DESCRITPION OF THE DRAWINGS
[0031] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this application, illustrate embodiment(s) of
the invention and together with the description serve to explain
the principle of the invention.
[0032] In the drawings;
[0033] FIG. 1 illustrates a system diagram of an air conditioner in
accordance with one preferred embodiment of the present
invention;
[0034] FIG. 2 illustrates a system diagram of an air conditioner in
accordance with another preferred embodiment of the present
invention;
[0035] FIG. 3 illustrates a system diagram of one preferred
embodiment of a subcooling device provided to the air conditioner
in FIGS. 1 or 2;
[0036] FIG. 4 illustrates a perspective view of one preferred
embodiment of a subcooling heat exchanger in the subcooling device
in FIG. 3;
[0037] FIG. 5 illustrates a perspective view of another preferred
embodiment of a subcooling heat exchanger in the subcooling device
in FIG. 3; and
[0038] FIG. 6 illustrates a P-h diagram of a refrigerating cycle of
a multi-type air conditioner of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. In describing the
embodiments, identical parts will be given the same names and
reference symbols, and repetitive description of which will be
omitted.
[0040] For better understanding of the present invention, functions
of the air conditioner will be described. The air conditioner
controls temperature, humidity, motion, and cleanliness of air so
as to be suitable to a purpose of use for a particular area, for an
example, room spaces, such as residential space, office,
restaurant, and the like.
[0041] In a cooling operation, the air conditioner cools a room by
compressing low pressure refrigerant having absorbed heat from the
room and discharging the heat to an outdoor air, and, in a heating
operation, heats the room by an opposite operation of the above
process.
[0042] FIG. 1 illustrates a system diagram of an air conditioner in
accordance with one preferred embodiment of the present invention,
of a concurrent heating/cooling multi-type air conditioner that
cools/heats rooms at the same time.
[0043] Referring to FIG. 1, the concurrent heating/cooling
multi-type air conditioner includes an outdoor unit 10, a
distributor 20, and a plurality of indoor units 30a, 30b, and 30c
in each of rooms.
[0044] The outdoor unit 10 includes a compressor 11, an outdoor
heat exchanger 12, an outdoor fan 13 on one side of the outdoor
heat exchanger, a switching device 15 for switching a compressed
refrigerant flow from the compressor 11 to the outdoor heat
exchanger or the distributor selectively proper to operation modes,
and accumulator 14 on a refrigerant pipeline connected to a suction
end of the compressor for separating vapor phase refrigerant from
liquid phase refrigerant.
[0045] The outer unit 10 is connected to the distributor 20 by the
switching device through a first pipeline 21 for guiding high
pressure refrigerant from the compressor 11 to the distributor
through the outdoor heat exchanger 12, a second refrigerant
pipeline 22 for guiding the refrigerant from the compressor 11 to
the distributor 20 directly, and a third refrigerant pipeline 23
connected between the distributor 20 and the suction end of the
compressor 11.
[0046] Each of the indoor units 30a, 30b, and 30c includes an
indoor heat exchanger 31a, 31b, or 31c, and an expansion device
32a, 32b, or 32c for expanding refrigerant introduced into the
indoor heat exchanger to a preset state in a cooling mode.
[0047] The distributor 20 is designed such that the refrigerant is
guided from the outdoor unit 10 to the expansion device 32a, 32b,
or 32c of the indoor unit directly if the indoor unit is operated
in the cooling mode, and the refrigerant is guided from the outdoor
unit 10 to the indoor heat exchanger 31a, 31b, or 31c of the indoor
unit directly if the indoor unit is operated in the heating
mode.
[0048] For this, the distributor 20 includes first refrigerant
branch pipelines 21a, 21b, and 21c branched from the first
refrigerant pipeline 21 as many as a number of the indoor units,
and connected to the indoor unit expansion devices 32a, 32b, and
32c respectively, second refrigerant branch pipelines 22a, 22b, and
22c branched from the second refrigerant pipeline and connected to
the indoor heat exchangers 31a, 31b, and 31c respectively, and
third refrigerant branch pipelines 23a, 23b, and 23c branched from
the third refrigerant pipeline 23, and connected to the indoor heat
exchangers 31a, 31b, and 31c, respectively. The second refrigerant
branch pipelines 22a, 22b, and 22c have first electronic shut off
valves 26a, 26b, and 26c, respectively, and the third refrigerant
branch pipeline 23a, 23b, and 23c have second electronic shut off
valves 27a, 27b, and 27c, respectively.
[0049] According to above system, in a case the indoor unit is
operated in the heating mode, the first electronic shut off valve
on the second refrigerant branch pipeline connected to the indoor
unit is opened, and the second electronic shut off valve on the
third refrigerant branch pipeline connected to the indoor unit is
closed, such that the refrigerant flows from the compressor 11 to
the indoor heat exchanger through the second refrigerant pipeline
22, and the second refrigerant branch pipeline connected to the
indoor unit. In a case of the indoor unit operated in the cooling
mode, the first electronic shut off valve on the second refrigerant
branch pipeline connected to the indoor unit operated in the
cooling mode is closed, and the second electronic shut off valve on
the third refrigerant branch pipeline connected to the indoor unit
is opened, such that the refrigerant having introduced through the
first refrigerant branch pipeline connected to the indoor unit, and
expanded at the indoor unit expansion device is introduced into the
third refrigerant pipeline 23 through the indoor heat exchanger of
the indoor unit and the third refrigerant branch pipeline connected
to the indoor unit.
[0050] Moreover, the distributor 20 includes a bypass pipe 25
connected between the second refrigerant pipeline 22, and the third
refrigerant pipeline 23, and an electronic conversion valve 25a on
the bypass pipe for converting high pressure refrigerant stagnant
at the second refrigerant pipeline 22 into a low pressure
refrigerant, for preventing liquefaction of the refrigerant due to
the stagnation of high pressure refrigerant in a case all the
indoor units are operated in the cooling mode.
[0051] In the meantime, the concurrent heating/cooling multi-type
air conditioner further includes a subcooling device 100 on the
first refrigerant pipeline 21 connected between the outdoor heat
exchanger 12 and the distributor 20.
[0052] The subcooling device 100 subcools the refrigerant passed
through a heat exchange process at the outdoor heat exchanger under
an isobaric condition, and guides to the distributor, i.e., expands
a portion of the refrigerant from the outdoor heat exchanger 12,
makes the expanded refrigerant to heat exchange with rest of the
refrigerant discharged from the outdoor heat exchanger, and flowing
toward the distributor 20 following the first refrigerant pipeline
21, and introduce into the third refrigerant pipeline 23 connected
between the distributor 20 and the suction end of the compressor
11. The subcooling device 100 will be described in detail with
reference to FIGS. 3.about.5, later.
[0053] In addition to above system, it is preferable that the
distributor 20 further includes a supplementary subcooling device
24 of a coaxial tube fitted between the distributor 20 and the
first refrigerant pipeline 21. The supplementary subcooling device
24 secures subcooling of the refrigerant introduced into the indoor
heat exchangers 31 a, 3 lb, and 31c by means of heat exchange
between refrigerants.
[0054] As another embodiment of the air conditioner of the present
invention, a cooling/heating selective multi-type air conditioner
will be described with reference to FIG. 2. FIG. 2 illustrates a
system diagram of an air conditioner in accordance with another
preferred embodiment of the present invention.
[0055] The cooling/heating selective multi-type air conditioner
includes an outdoor unit 50, a distributor 60, and a plurality of
indoor units 70a, 70b, and 70c in each room, for operating all the
indoor units in a cooling mode, or heating mode.
[0056] The outdoor unit 50 includes a compressor 51, an outdoor
heat exchanger 52, an outdoor fan 53 on one side of the outdoor
heat exchanger, a switching device 55 for switching a compressed
refrigerant flow from the compressor 51 to the outdoor heat
exchanger or the distributor selectively proper to operation modes,
and an accumulator 54 on a refrigerant pipeline connected to a
suction end of the compressor 51 for separating vapor phase
refrigerant from liquid phase refrigerant.
[0057] The outer unit 50 is connected to the distributor 60 by the
switching device 55 through a first pipeline 61 for guiding high
pressure refrigerant from the compressor 51 to the distributor
through the outdoor heat exchanger 52, a second refrigerant
pipeline 62 having one end connected to a refrigerant pipeline
connected to a discharge end of the compressor 51 for guiding the
refrigerant from the compressor 51 to the distributor 60 directly,
and a third refrigerant pipeline 63 connected between the
distributor 60 and the suction end of the compressor 51.
[0058] Each of the indoor units includes an indoor heat exchanger
71a, 71b, or 71c, and an expansion device 72a, 72b, or 72c for
expanding refrigerant introduced into the indoor heat exchanger to
a preset state in a cooling mode.
[0059] The distributor 60 is designed such that the refrigerant is
guided from the first connection pipeline 61 to the expansion
device 72a, 72b, or 72c of the indoor unit directly if all the
indoor units 70a, 70b, and 70c are operated in the cooling mode,
and the refrigerant is guided from the first connection pipeline 62
to the indoor heat exchanger 71a, 71b, or 71c of the indoor unit
directly if all the indoor units 70a, 70b, and 70c are operated in
the heating mode.
[0060] For this, the distributor 60 includes first refrigerant
branch pipelines 61a, 61b, and 61c branched from the first
refrigerant pipeline 61 as many as a number of the indoor units
70a, 70b, and 70c, and connected to the indoor unit expansion
devices 72a, 72b, and 72c respectively, second refrigerant branch
pipelines 62a, 62b, and 62c branched from the second refrigerant
pipeline 62 and connected to the indoor heat exchangers 71a, 71b,
and 71c of the indoor units respectively, and an electronic shut
off valves 64 at a position before the second refrigerant pipeline
62 is branched to the second refrigerant branch pipelines. The
third refrigerant pipeline 63 is connected to the other end of the
second refrigerant pipeline 62.
[0061] According to above system, in a case all the indoor units
70a, 70b, and 70c are operated in the cooling mode, the electronic
shut off valve 64 on the second refrigerant branch pipeline 62 is
closed, such that the refrigerant flows from the compressor 51 to
the expansion devices 72a, 72b, and 72c through the first
refrigerant branch pipelines 61a, 61b, and 61c connected to the
first refrigerant pipeline 61 and the indoor units 70a, 70b, and
70c by the switching device 55, and expands at the expansion
devices 72a, 72b, and 72c, and is drawn into the compressor 51
through the indoor heat exchanger 71a, 71b, and 71c, the second
refrigerant branch pipelines 62a, 62b, and 62c, and the third
refrigerant pipeline 63.
[0062] In a case all the indoor units 70a, 70b, and 70c are
operated in the heating mode, the electronic shut off valve 64 on
the second refrigerant branch pipeline 62 is opened, such that the
refrigerant flows from the compressor 51 to the indoor heat
exchangers 71a, 71b, and 71c through the second refrigerant branch
pipelines 61a, 61b, and 61c connected to the second refrigerant
pipeline 62 and the indoor units 70a, 70b, and 70c by the switching
device 55, heat exchanges at the indoor heat exchangers 71a, 71b,
and 71c, and is drawn into the compressor 51 through the expansion
devices 72a, 72b, and 72c, the first refrigerant branch pipelines
61a, 61b, and 61c, and the first refrigerant pipeline 61.
[0063] In the meantime, the heating/cooling selective multi-type
air conditioner further includes a subcooling device 100 on the
first refrigerant pipeline 21 connected between the outdoor heat
exchanger 12 and the distributor 20.
[0064] The subcooling device 100 subcools the refrigerant passed
through a heat exchange process at the outdoor heat exchanger 52
under an isobaric condition, and guides to the distributor, i.e.,
expands a portion of the refrigerant from the outdoor heat
exchanger 52, makes the expanded refrigerant to heat exchange with
rest of the refrigerant discharged from the outdoor heat exchanger,
and flowing toward the distributor 60 following the first
refrigerant pipeline 61, and introduce into the third refrigerant
pipeline 63 connected between the distributor 60 and the suction
end of the compressor 51.
[0065] A system of the subcooling device 100 applied to the
concurrent, or selective heating/cooling multi-type air conditioner
will be described with reference to FIGS. 3.about.5.
[0066] The subcooling device 106 includes a subcooling heat
exchanger 110, an expansion device 120, and connection pipes to the
subcooling heat exchanger.
[0067] In more detail, the subcooling device 100 includes a
subcooling heat exchanger 110 for heat exchange between a portion
of refrigerant expanded and rest of refrigerant not expanded, a
first connection pipeline 131 having the expansion device 120 for
expanding the portion of refrigerant passed through a heat exchange
process at the outdoor heat exchanger, and connected to the first
refrigerant pipeline 21, or 61 for guiding expanded refrigerant to
the subcooling heat exchanger 110, a second connection pipeline 132
for guiding the refrigerant not expanded to the subcooling heat
exchanger 110, a third connection pipeline 133 for guiding the
unexpanded refrigerant passed through, heat exchanged, and
subcooled at the subcooling heat exchanger 110 to the distributor
20 or 60, and a fourth connection pipeline 134 for guiding the
expanded refrigerant passed through, and heat exchanged at the
subcooling heat exchanger to the third refrigerant pipeline
connected to the suction end of the compressor 11 or 51.
[0068] The subcooling heat exchanger 110 has flow passages designed
to introduce the refrigerant from the outdoor heat exchanger 12 or
52 in a plurality of paths. For this, it is preferable that the
subcooling heat exchanger 110 includes a first flow pipeline 111
having one end connected to the second connection pipeline 132, and
the other end connected to the third connection pipeline 133 for
flow of the unexpanded high temperature refrigerant, and a second
flow pipeline 112 having one end connected to the first connection
pipeline 131, and the other end connected to the fourth connection
pipeline 134, for heat exchange with the first flow pipeline 111,
and flow of the low temperature expanded refrigerant.
[0069] It is preferable that the subcooling heat exchanger 110 has
a double pipe structure with an inner flow pipe and an outer flow
pipe on an outside of the inner flow pipe, for improving a heat
exchange efficiency of the refrigerant.
[0070] In the present invention, it is preferable that the inner
flow pipe is the second flow pipeline 112, and the outer flow pipe
is the first flow pipeline 111, for flow of the expanded low
temperature refrigerant in the inner flow pipe 112, and the high
temperature refrigerant discharged from the outdoor heat exchanger
12 or 52 in the outer flow pipe 111, to prevent dew from forming on
a surface of the subcooling heat exchanger 110. Of course, it is
apparent that the outer flow pipe of the subcooling heat exchanger
110 can be connected to the first connection pipeline 131, and the
second connection pipeline 132 can be connected to the second
connection pipeline 132. However, in this instance, since the outer
flow pipeline has the relatively low temperature refrigerant
flowing therein, it is liable that dew is formed on the surface of
the subcooling heat exchanger 110.
[0071] The subcooling heat exchanger 110 may have a variety of
structures as far as the structure brings the two flow pipes 111,
and 112 into contact. As one example, the subcooling heat exchanger
may have a structure in which the second flow pipe winds the first
flow pipe several times. Moreover, it is preferable that the two
flow pipes 111, and 112 are formed of a material having a good
thermal conductivity.
[0072] In order to prevent liquid refrigerant from entering into
the compressor, it is preferable that the fourth connection
pipeline 134 is connected to a predetermined position of the third
refrigerant pipeline 23, and 63 which is connected to the inlet of
the accumulator 14 or 54.
[0073] Of course, it is apparent that the fourth connection
pipeline 134 can be connected to the third refrigerant pipeline 23
between the compressor 11, or 51, and the accumulator 14, or 54.
Since the refrigerant is expanded to a substantially gas state,
even though the refrigerant is introduced into the compressor 11,
or 51, stability of the compressor 11, or 51 is not harmed
much.
[0074] It is preferable that the first to fourth pipelines 131,
132, 133, and 134 are connected to the subcooling heat exchanger
110 such that the high temperature refrigerant flowing in the first
flow pipeline 111 has a flow direction opposite to a flow direction
of the low temperature expanded refrigerant, for enhancing a heat
exchange efficiency. Of course, depending on a design condition of
the subcooling heat exchanger 100, it is possible that the first to
fourth pipelines 131, 132, 133, and 134 are connected to the
subcooling heat exchanger 110 such that the high temperature
refrigerant flowing in the first flow pipeline 111 has a flow
direction opposite to a flow direction of the low temperature
expanded refrigerant.
[0075] It is preferable that the inner flow pipe of the subcooling
heat exchanger has a heat exchange part 113a, or 113b for making a
heat exchange area larger.
[0076] In more detail, the heat exchange part 113a, or 113b are
inward projections from the inner flow pipe, the second flow pipe
112, for preventing an increase of flow resistance of the
refrigerant flowing along the first flow pipeline 111, and
increasing a heat exchange area of the refrigerant flowing through
the second flow pipeline 112.
[0077] Of course, the heat exchange part 113a, or 113b may be
formed both on the inside/outside walls of the inner flow pipe, or
both on the inside/outside of the inner flow pipe, and on an inside
wall of the outer flow pipeline.
[0078] The heat exchange part 113a, or 113b may be formed on the
inside wall surface of the inner flow pipe in a form of a ring
along a circumferential direction, or as shown in FIG. 4, in a form
of a helix along the flow direction, or as shown in FIG. 5, in a
form thin, and extended along the flow direction of the
refrigerant. Those structures enable to increase the thermal
efficiency of the refrigerant, while decreasing a flow resistance
of the expanded refrigerant.
[0079] Above forms of the heat exchange part 113a, or 113b are only
a few embodiments, and it is apparent that there can be many
variations of the heat exchange part 113a, or 113b.
[0080] It is preferable that the subcooling device 100 with the
subcooling heat exchanger 110 is mounted on an inside of the
outdoor unit 10 or 50. In more detail, a length of the first
refrigerant pipeline 21 or 61 between the subcooling device 100 and
the outdoor heat exchanger 12 or 52 is made shorter, to make the
refrigerant from the outdoor heat exchanger 12 or 52 heat exchange,
for preventing expansion of a portion of the refrigerant in the
first refrigerant pipeline 21, and subcooled liquid refrigerant is
supplied to the distributor 20, for minimizing pressure drop of the
refrigerant at the first refrigerant pipeline 21, or 61.
[0081] It is preferable that the subcooling heat exchanger 110 has
a length of 1.about.2.5 m, for adequate heat exchange of the low
temperature refrigerant expanded at the expansion device 120 on the
first connection pipeline 131 and the unexpanded refrigerant
flowing through the second connection pipeline at the subcooling
heat exchanger 110.
[0082] Since operations of the subcooling devices 100 provided to
the concurrent heating/cooling multi-type air conditioner, and the
selective heating/cooling multi-type air conditioner are almost
identical, the operation of the present invention will be described
with reference to the concurrent heat/cooling multi-type air
conditioner a majority of which indoor units 30b and 30c are in
cooling mode, and a minority of which indoor units 30a are in a
heating mode.
[0083] At first, when the concurrent heat/cooling multi-type air
conditioner is put into operation, the refrigerant compressed to a
high pressure at, and discharged from the compressor 11 is
introduced into the outdoor heat exchanger 12 by the switching
device 15. The high pressure refrigerant heat exchanges with the
outdoor air, and condenses as the outdoor fan 13 rotates, and
discharged to the first refrigerant pipeline 21 connected to the
subcooling device 100.
[0084] A portion of the refrigerant introduced into the subcooling
device 100 following the first refrigerant pipeline 21 is expanded
to a low temperature refrigerant by the expansion device 120 on the
first connection pipeline 131, and flows through the second flow
pipeline 112, rest of the refrigerant introduced into the
subcooling device 100 following the first refrigerant pipeline 21
is introduced into the first flow pipeline 111 by the second
connection pipeline 132, to heat transfer to each other, such that
the refrigerant flowing through the first flow pipeline 111 is
subcooled under an isobaric state.
[0085] Next, the refrigerant from the first flow pipeline 111 of
the subcooling heat exchanger 110 is introduced into the
distributor 20 through the third connection pipeline 133 and the
first refrigerant pipeline 21 in an unexpanded state, guided to the
indoor units 30b, and 30c through the first refrigerant branch
pipelines 21b and 21c connected to the indoor units operative in
the cooling mode, passes through an expansion process and heat
exchange process to cool respective rooms, is drawn into the
compressor 11 through the third refrigerant branch pipeline 23b,
and 23c, the third refrigerant pipeline 23, and the accumulator
14.
[0086] The refrigerant from the second flow pipeline 112 of the
subcooling heat exchanger 110 is introduced into the accumulator 14
guided by the fourth connection pipeline 134 and the third
connection pipeline 23, separated into gaseous refrigerant and
liquid refrigerant, and drawn into the compressor 11.
[0087] In the meantime, a portion of the refrigerant from the
compressor 11 is introduced into the distributor 20 directly
without passing through the outdoor heat exchanger 12, and
introduced into the indoor unit 30a through the second refrigerant
branch pipeline 22a connected to the indoor unit 30a operative in
the heating mode, passes through a heat exchange process to heat
the room, and joins with the refrigerant flowing through the first
refrigerant pipeline following through the first refrigerant branch
pipeline 21a connected to the indoor unit operative in the heating
mode.
[0088] FIG. 6 illustrates a P-h diagram of a refrigerating cycle of
a multi-type air conditioner of the present invention.
[0089] The air conditioner of the present invention has the
following advantages.
[0090] First, even if a length of the first refrigerant pipeline
between the outdoor unit and the indoor unit is extensive,
refrigerant pressure drop is minimized and refrigerant capability
is improved owing to the subcooling device that provides subcooled
refrigerant.
[0091] Second, the noise occurred at the time of expansion of the
refrigerant at the expansion device of the indoor unit can be
minimized owing to introduction of the subcooled high pressure
refrigerant thereto.
[0092] Third, the minimized pressure drop of the refrigerant
introduced into the indoor unit permits to minimize a capacity of
the compressor provided to the air conditioner, enabling to save a
production cost, and minimize a volume of the air conditioner.
[0093] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit or scope of the invention. Thus,
it is intended that the present invention cover the modifications
and variations of this invention provided they come within the
scope of the appended claims and their equivalents.
* * * * *