U.S. patent application number 11/286354 was filed with the patent office on 2006-06-01 for air conditioning system.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Se-Dong Chang, Baik-Young Chung, Ju-Won Kim, Sai-Kee Oh, Bong-Soo Park, Chi-Woo Song.
Application Number | 20060112712 11/286354 |
Document ID | / |
Family ID | 35884025 |
Filed Date | 2006-06-01 |
United States Patent
Application |
20060112712 |
Kind Code |
A1 |
Chang; Se-Dong ; et
al. |
June 1, 2006 |
Air conditioning system
Abstract
An air conditioning system comprises an indoor unit in which a
first refrigerant flows, a first tank connected to an outlet side
refrigerant line of the indoor unit for sucking a first
refrigerant, a second tank connected to an inlet side refrigerant
line of the indoor unit and directly connected to the first tank at
a position lower than the first tank for feeding back the first
refrigerant stored in the first tank to the indoor unit, a
connection line disposed between the first tank and the second
tank, a pressure equalizing line disposed between the first tank
and the second tank, a heat source cycle for cooling the first
refrigerant inside the first tank by circulating a second
refrigerant and heating the first refrigerant of the second tank,
and a controller for controlling a plurality of switching valves
installed at the connection line and the pressure equalizing
line.
Inventors: |
Chang; Se-Dong; (Seoul,
KR) ; Oh; Sai-Kee; (Seoul, KR) ; Song;
Chi-Woo; (Seoul, KR) ; Chung; Baik-Young;
(Seoul, KR) ; Kim; Ju-Won; (Seoul, KR) ;
Park; Bong-Soo; (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: |
35884025 |
Appl. No.: |
11/286354 |
Filed: |
November 25, 2005 |
Current U.S.
Class: |
62/324.1 ;
62/434 |
Current CPC
Class: |
F25B 25/005 20130101;
F25B 2500/01 20130101; F25B 2400/16 20130101; F25B 13/00 20130101;
F25B 2700/04 20130101 |
Class at
Publication: |
062/324.1 ;
062/434 |
International
Class: |
F25B 13/00 20060101
F25B013/00; F25D 17/02 20060101 F25D017/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2004 |
KR |
98192/2004 |
Claims
1. An air conditioning system, comprising: an indoor unit in which
a first refrigerant flows; a first tank connected to an outlet side
refrigerant line of the indoor unit for sucking a first
refrigerant; a second tank connected to an inlet side refrigerant
line of the indoor unit and directly connected to the first tank at
a position lower than the first tank for feeding back the first
refrigerant stored in the first tank to the indoor unit; a
connection line disposed between the first tank and the second
tank; a pressure equalizing line disposed between the first tank
and the second tank; a heat source cycle for cooling the first
refrigerant inside the first tank by circulating a second
refrigerant, and heating the first refrigerant of the second tank;
and a controller for controlling a plurality of switching valves
installed at the connection line and the pressure equalizing
line.
2. The air conditioning system of claim 1, wherein the heat source
cycle comprises: a cooling unit installed at the first tank; a
heating unit connected to the cooling unit and installed at the
second tank; a compressor for supplying a second refrigerant to the
cooling unit and the heating unit; a first four-way valve installed
at an outlet side refrigerant line of the compressor; an
accumulator installed between the compressor and the first four-way
valve for introducing a second gaseous refrigerant to the
compressor; an outdoor heat exchanger for selectively radiating a
second refrigerant discharged from the compressor; a second
four-way valve installed at an inlet side refrigerant line of the
second tank; and an expansion valve installed at a refrigerant line
between the cooling unit and the heating unit.
3. The air conditioning system of claim 2, wherein the cooling unit
is installed in the first tank, and the heating unit is installed
in the second tank.
4. The air conditioning system of claim 1, further comprising: a
diaphragm installed in the first tank for dividing an inner space
of the first tank into an upper space and a lower space; a first
liquid refrigerant feed back line connecting the upper space to the
lower space and installed in the first tank, for feeding back the
first liquid refrigerant of the first tank into the second tank;
and a check valve installed at the first liquid refrigerant feed
back line.
5. The air conditioning system of claim 4, wherein the diaphragm is
horizontally disposed.
6. The air conditioning system of claim 1, wherein one side of the
connection line is connected to a lower portion of the first tank
and another side of the connection line is connected to a lower
portion of the second tank, one side of the pressure equalizing
line is connected to a lower portion of the first tank and another
side of the pressure equalizing line is connected to an upper
portion of the second tank, and the pressure equalizing line is
positioned to be higher than the connection line.
7. The air conditioning system of claim 1, wherein a refrigerant
level sensor for detecting a level of the first liquid refrigerant
inside the first tank is installed in the first tank.
8. The air conditioning system of claim 1, further comprising: a
cooling line having one side connected to a lower portion of the
second tank and another side connected to the indoor unit, for
introducing a first liquid refrigerant into the indoor unit; a
cooling line switching valve installed at the cooling line for
selectively opening or closing the cooling line; a heating line
having one side connected to an upper portion of the second tank
and another side connected to the indoor unit, for introducing a
first gaseous refrigerant into the indoor unit; and a heating line
switching valve installed at the heating line for selectively
opening or closing the heating line.
9. An air conditioning system, comprising: a first tank connected
to an outlet side refrigerant line of an indoor unit for sucking a
first liquid refrigerant; a second tank connected to an inlet side
refrigerant line of the indoor unit and directly connected to the
first tank at a position lower than the first tank for feeding back
the first liquid refrigerant stored in the first tank to the indoor
unit.
10. The air conditioning system of claim 9, further comprising: a
cooling unit installed at the first tank; a heating unit connected
to the cooling unit and installed at the second tank; a compressor
for supplying a second refrigerant to the cooling unit and the
heating unit; a first four-way valve installed at an outlet side
refrigerant line of the compressor; an accumulator installed
between the compressor and the first four-way valve for introducing
a second gaseous refrigerant to the compressor; an outdoor heat
exchanger for selectively radiating a second refrigerant discharged
from the compressor; a second four-way valve installed at an inlet
side refrigerant line of the second tank; and an expansion valve
installed at a refrigerant line between the cooling unit and the
heating unit.
11. The air conditioning system of claim 10, wherein the cooling
unit is installed in the first tank, and the heating unit is
installed in the second tank.
12. The air conditioning system of claim 9, further comprising: a
diaphragm installed in the first tank for dividing an inner space
of the first tank into an upper space and a lower space; a first
liquid refrigerant feed back line installed in the first tank for
feeding back the first liquid refrigerant of the first tank into
the second tank; and a check valve installed at the first liquid
refrigerant feed back line.
13. The air conditioning system of claim 12, wherein the diaphragm
is horizontally disposed.
14. The air conditioning system of claim 9, wherein one side of the
connection line is connected to a lower portion of the first tank
and another side of the connection line is connected to a lower
portion of the second tank, one side of the pressure equalizing
line is connected to a lower portion of the first tank and another
side of the pressure equalizing line is connected to an upper
portion of the second tank, and the pressure equalizing line is
positioned to be higher than the connection line.
15. The air conditioning system of claim 9, further comprising: a
cooling line having one side connected to a lower portion of the
second tank and another side connected to the indoor unit, for
introducing a first liquid refrigerant into the indoor unit; a
cooling line switching valve installed at the cooling line for
selectively opening or closing the cooling line; a heating line
having one side connected to an upper portion of the second tank
and another side connected to the indoor unit, for introducing a
first gaseous refrigerant into the indoor unit; and a heating line
switching valve installed at the heating line for selectively
opening or closing the heating line.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an air conditioning system,
and more particularly, to an air conditioning system having an
improved refrigerant circulation structure capable of smoothly
feeding back a refrigerant that circulates a refrigerant
circulation system.
[0003] 2. Description of the Background Art
[0004] FIG. 1 is a construction view showing an air conditioning
system in accordance with the conventional art.
[0005] As shown, the conventional air conditioning system comprises
an indoor unit 111 for introducing a first refrigerant, a suction
tank 121 connected to an outlet side refrigerant line 111b of the
indoor unit 111 for sucking a first refrigerant, a discharge tank
141 disposed to be lower than the suction tank 121 and connected to
an inlet side refrigerant line 111a of the indoor unit 111 for
discharging a first refrigerant to the indoor unit 111, a middle
tank 131 installed between the suction tank 121 and the discharge
tank 141 for feeding back the first refrigerant stored in the
suction tank 121 to the discharge tank 141, and a heat source cycle
150 for depressurizing and cooling the first refrigerant of the
suction tank 121 by circulating a second refrigerant, and heating
the first refrigerant of the discharge tank 141.
[0006] The discharge tank 141 is positioned to be lower than the
middle tank 131, and the middle tank 131 is positioned to be lower
than the suction tank 121. That is, the suction tank 121, the
middle tank 131, and the discharge tank 141 are sequentially
positioned.
[0007] A first connection line 125 for connecting a lower portion
of the suction tank 121 to a lower portion of the middle tank 131
is installed between the suction tank 121 and the middle tank 131.
A switching valve 137 is installed at the first connection line
125.
[0008] A first pressure equalizing line 123 for connecting a lower
portion of the suction tank 121 to an upper portion of the middle
tank 131 is installed between the suction tank 121 and the middle
tank 131. The switching valve 137 is installed at the first
pressure equalizing line 123.
[0009] A second connection line 135 for connecting a lower portion
of the middle tank 131 to a lower portion of the discharge tank 141
is installed between the middle tank 131 and the discharge tank
141. The switching valve 137 is installed at the second connection
line 135.
[0010] A second pressure equalizing line 133 for connecting an
upper portion of the middle tank 131 to an upper portion of the
discharge tank 141 is installed between the middle tank 131 and the
discharge tank 141. The switching valve 137 is installed at the
second pressure equalizing line 133.
[0011] The heat source cycle 150 comprises a compressor 151 for
compressing a second refrigerant, a condenser 153 connected to an
outlet side refrigerant line 151a of the compressor 151 and
heat-exchanging with a first refrigerant inside the discharge tank
141, an evaporator 155 connected to an inlet side refrigerant line
151b of the compressor 151 and heat-exchanging with a first
refrigerant inside the suction tank 121, and an outdoor expansion
valve 157 installed at an outlet side refrigerant line 153a of the
condenser 153.
[0012] In the conventional air conditioning system, in case of the
heat source cycle 150, a second refrigerant provided from the
compressor 151 passes through the condenser 153, the outdoor
expansion valve 157, and the evaporator 155, and then is returned
to the compressor 151, which is repeated.
[0013] In case of a heat driving system 110, a first refrigerant
supplied from the discharge tank 141 passes through the indoor unit
111, and then is fed back to the suction tank 121, the middle tank
131, and the discharge tank 141, which is repeated.
[0014] The first refrigerant inside the discharge tank 141 is
heat-exchanged by the condenser 153 thus to be introduced into the
indoor unit 111. Then, the first refrigerant introduced into the
indoor unit 111 is heat-exchanged via an indoor expansion valve 115
and an indoor heat exchanger 113, thereby heating or cooling an
indoor room.
[0015] The first refrigerant having passed through the indoor unit
111 is introduced into the suction tank 121, and then is
heat-exchanged by the evaporator thus to be condensed. When the
first refrigerant having an amount more than a certain degree is
stored in the suction tank 121, a controller (not shown) controls
each switching valve 137 of the first pressure equalizing line 123
and the first connection line 125. Accordingly, the first
refrigerant stored in the suction tank 121 is fed back to the
middle tank 131 by a height difference between the suction tank 121
and the middle tank 131 and by a gravitation.
[0016] Next, the controller controls each switching valve 137 of
the second pressure equalizing line 133 and the second connection
line 135 in the same manner as the aforementioned manner.
Accordingly, the first refrigerant stored in the middle tank 131 is
fed back to the discharge tank 141.
[0017] However, in the conventional air conditioning system, the
first liquid refrigerant stored in the suction tank is fed back to
the discharge tank via the middle tank. Accordingly, an entire
volume of the air conditioning system is increased and an entire
height of the air conditioning system is increased, thereby having
a limitation in installing the air conditioning system and
increasing a fabrication cost.
[0018] Furthermore, in the conventional air conditioning system,
the first refrigerant has to be fed back by a height difference
among the suction tank, the middle tank, and the discharge tank and
by gravitation. Accordingly, the first refrigerant more than a
certain amount has to be stored in the suction tank and the
discharge tank.
BRIEF DESCRIPTION OF THE INVENTION
[0019] Therefore, an object of the present invention is to provide
an air conditioning system capable of simplifying an entire
structure thereof, facilitating to be installed, and reducing a
fabrication cost.
[0020] Another object of the present invention is to provide an air
conditioning system capable of minimizing an amount of a first
refrigerant stored in a first tank and a second tank.
[0021] To achieve these and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described herein, there is provided an air conditioning system,
comprising: an indoor unit in which a first refrigerant flows; a
first tank (a suction tank) connected to an outlet side refrigerant
line of the indoor unit for sucking a first refrigerant; a second
tank (a discharge tank) disposed to be lower than the suction tank
and connected to an inlet side refrigerant line of the indoor unit
for feeding back the first refrigerant stored in the first tank to
the indoor unit; a connection line disposed between the first tank
and the second tank; a pressure equalizing line disposed between
the first tank and the second tank; a heat source cycle for cooling
the first refrigerant inside the suction tank by circulating a
second refrigerant, and heating the first refrigerant of the
discharge tank; and a controller for controlling a plurality of
switching valves installed at the connection line and the pressure
equalizing line.
[0022] On a heat driving system including the indoor unit, the
first tank, and the second tank, the first refrigerant flows.
However, on the heat source cycle, the second refrigerant
flows.
[0023] In the heat driving system, the first refrigerant discharged
from the second tank is introduced into the first tank via the
indoor unit. The first gaseous refrigerant introduced into the
first tank is cooled and depressurized by a cooling unit of the
heat source cycle that will be later explained, and thus is
condensed into a first liquid refrigerant. The first liquid
refrigerant is directly fed back to the second tank without passing
through a middle tank differently from the conventional art. Then,
the first liquid refrigerant is introduced into the indoor unit via
a cooling line at the time of a cooling operation, or is converted
into a first gaseous refrigerant at the time of a heating operation
thus to be introduced into the indoor unit via a heating line. The
above circulation process is repeatedly performed.
[0024] The first tank is provided with a diaphragm therein, the
diaphragm for dividing an inner space of the first tank into an
upper space and a lower space.
[0025] A first liquid refrigerant feed back line is installed in
the first tank, and a check valve for preventing a backflow of a
first liquid refrigerant is installed at the first liquid
refrigerant feed back line.
[0026] One side of the connection line is connected to a lower
portion of the first tank, and another side thereof is connected to
a lower portion of the second tank. One side of the pressure
equalizing line is connected to a lower portion of the first tank,
and another side of the pressure equalizing line is connected to an
upper portion of the second tank. The pressure equalizing line is
positioned to be higher than the connection line.
[0027] A refrigerant level sensor for detecting a level of the
first liquid refrigerant inside the first tank is installed in the
lower space of the first tank.
[0028] The controller controls the switching valves according to a
detected result of the refrigerant level sensor.
[0029] A cooling line is installed between the indoor unit and the
second tank. One side of the cooling line is connected to a lower
portion of the second tank and another side thereof is connected to
the indoor unit so as to introduce a first liquid refrigerant into
the indoor unit.
[0030] A heating line is installed between the indoor unit and the
second tank. One side of the heating line is connected to an upper
portion of the second tank and another side thereof is connected to
the indoor unit so as to introduce a first gaseous refrigerant into
the indoor unit. A heating line switching valve for switching the
heating line is installed at the heating line.
[0031] The heat source cycle comprises a cooling unit installed at
the first tank, a heating unit connected to the cooling unit and
installed at the second tank, a compressor for supplying a second
refrigerant to the cooling unit and the heating unit, a first
four-way valve installed at an outlet side refrigerant line of the
compressor, an accumulator installed between the compressor and the
first four-way valve for introducing a second gaseous refrigerant
to the compressor, an outdoor heat exchanger for selectively
radiating a second refrigerant discharged from the compressor, a
second four-way valve installed at an inlet side refrigerant line
of the second tank, and an expansion valve installed at a
refrigerant line between the cooling unit and the heating unit.
[0032] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0034] In the drawings:
[0035] FIG. 1 is a construction view showing an air conditioning
system in accordance with the conventional art;
[0036] FIG. 2 is a construction view showing an air conditioning
system according to a preferred embodiment of the present
invention, which shows a refrigerant flow at the time of a cooling
operation;
[0037] FIG. 3 is a block diagram showing a control process of the
air conditioning system of FIG. 2; and
[0038] FIG. 4 is a construction view showing the air conditioning
system according to a preferred embodiment of the present
invention, which shows a refrigerant flow at the time of a heating
operation.
DETAILED DESCRIPTION OF THE INVENTION
[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.
[0040] Hereinafter, an air conditioning system according to a
preferred embodiment of the present invention will be explained
with reference to the attached drawings.
[0041] FIG. 2 is a construction view showing an air conditioning
system according to a preferred embodiment of the present
invention, which shows a refrigerant flow at the time of a cooling
operation, FIG. 3 is a block diagram showing a control process of
the air conditioning system of FIG. 2, and FIG. 4 is a construction
view showing the air conditioning system according to a preferred
embodiment of the present invention, which shows a refrigerant flow
at the time of a heating operation.
[0042] As shown, the air conditioning system according to the
present invention comprises an indoor unit 11 for introducing a
first refrigerant, a first tank 21 connected to an outlet side
refrigerant line 11a of the indoor unit 11 for sucking a first
refrigerant, a second tank 41 directly connected to the first tank
21 at a position lower than the first tank 21 and connected to an
inlet side refrigerant line 11b of the indoor unit 11 for feeding
back the first refrigerant stored in the first tank 21 to the
indoor unit, a connection line 31 disposed between the first tank
21 and the second tank 41, a pressure equalizing line 35 disposed
between the first tank 21 and the second tank 41, a heat source
cycle 2 for cooling the first refrigerant inside the first tank 21
by circulating a second refrigerant and heating the first
refrigerant of the second tank 41, and a controller 65 for
controlling a plurality of switching valves 33 and 37 installed at
the connection line 31 and the pressure equalizing line 35.
[0043] The indoor unit 11 is installed at an indoor room in order
to perform a cooling operation or a heating operation. An indoor
heat exchanger 13 and an indoor expansion valve 15 are installed in
the indoor unit 11.
[0044] On a heat driving system 1 including the indoor unit 11, the
first tank 21, and the second tank 41, the first refrigerant flows.
However, on the heat source cycle 2, the second refrigerant flows.
The first refrigerant and the second refrigerant are converted into
a liquid phase and a gaseous phase while flowing on the heat
driving system and the heat source cycle, respectively, thereby
performing a heat exchange.
[0045] In the heat driving system 1, the first refrigerant
discharged from the second tank 41 is introduced into the first
tank 21 via the indoor unit 11. A first gaseous refrigerant of the
first refrigerant introduced into the first tank 21 is cooled and
depressurized by a cooling unit 54 of the heat source cycle 2 that
will be later explained, and thus is condensed into a first liquid
refrigerant. The first liquid refrigerant is directly fed back to
the second tank 41 by the controller 65 without passing through a
middle tank differently from the conventional art.
[0046] Then, the first liquid refrigerant fed back to the second
tank 41 is introduced into the indoor unit 11 via a cooling line 43
with a low temperature and pressure state at the time of a cooling
operation. On the contrary, at the time of a heating operation, the
first gaseous refrigerant of an upper space 41a of the second tank
41 is introduced into the indoor unit 11 via a heating line 47 with
a high temperature and pressure state. The above circulation
process is repeatedly performed.
[0047] The first tank 21 is provided with a diaphragm 23 therein,
the diaphragm for dividing an inner space of the first tank 21 into
an upper space 21a and a lower space 21b.
[0048] A first liquid refrigerant feed back line 25 for feeding
back the first liquid refrigerant disposed on the diaphragm 23 of
the upper space 21a to the lower space 21b is installed in the
first tank 21.
[0049] Also, a check valve 27 for preventing a backflow of the
first liquid refrigerant is installed at the first liquid
refrigerant feed back line 25.
[0050] Preferably, the diaphragm 23 is horizontally installed for
the following reason. The first gaseous refrigerant introduced into
the first tank 21 is condensed into a first liquid refrigerant, and
then is disposed on the diaphragm 23. The first liquid refrigerant
disposed on the diaphragm 23 is smoothly fed back to the second
tank 41 through the first liquid refrigerant feed back line 25 and
a connection line 31 that will be later explained.
[0051] One side of the connection line 31 is connected to a lower
portion of the first tank 21, and another side thereof is connected
to a lower portion of the second tank 41. The switching valve 33
for selectively opening or closing the connection line 31 is
installed at the connection line 31.
[0052] One side of the pressure equalizing line 35 is connected to
a lower portion of the first tank 21, and another side of the
pressure equalizing line 35 is connected to an upper portion of the
second tank 41. The switching valve 37 for selectively opening or
closing the pressure equalizing line 35 is installed at the
pressure equalizing line 35. The pressure equalizing line 35 is
positioned to be higher than the connection line 31.
[0053] A refrigerant level sensor 28 for detecting a level of the
first liquid refrigerant inside the first tank 21 is installed in
the lower space 21b of the first tank 21.
[0054] The controller 65 controls a first four-way valve and a
second four-way valve at the time of a cooling operation and a
heating operation. Also, the controller 65 controls the switching
valves 33 and 37 according to a detected result of the refrigerant
level sensor 28.
[0055] The cooling line 43 is installed between the indoor unit 11
and the second tank 41. One side of the cooling line 43 is
connected to a lower portion of the second tank 41 and another side
thereof is connected to the indoor unit 11 so that the first liquid
refrigerant can be introduced into the indoor unit 11. A switching
valve 45 for selectively opening or closing the cooling line 43 is
installed at the cooling line 43.
[0056] The heating line 47 is installed between the indoor unit 11
and the second tank 41. One side of the heating line 47 is
connected to an upper portion of the second tank 41 and another
side thereof is connected to the indoor unit 11 so that the first
liquid refrigerant can be introduced into the indoor unit 11. A
switching valve 49 for selectively opening or closing the heating
line 47 is installed at the heating line 43.
[0057] The heat source cycle comprises a cooling unit 54 installed
at the first tank 21, a heating unit 52 connected to the cooling
unit 54 and installed at the second tank 41, a compressor 51 for
supplying a second refrigerant to the cooling unit 54 and the
heating unit 52, a first four-way valve 53 installed at an outlet
side refrigerant line 51a of the compressor 51 for converting a
second refrigerant line, an accumulator 59 installed between the
compressor 51 and the first four-way valve 53 for introducing a
second gaseous refrigerant to the compressor 51, an outdoor heat
exchanger 55 for selectively radiating a second refrigerant
discharged from the compressor 51, a second four-way valve 61
installed at an inlet side refrigerant line 41a of the second tank
41 for converting a second refrigerant line, and an expansion valve
63 installed at a refrigerant line between the cooling unit 54 and
the heating unit 52.
[0058] The cooling unit 54 is installed in the first tank 21, and
the heating unit 52 is installed in the second tank 41.
[0059] Besides the structure that the cooling unit 54 is installed
in the first tank 21 and the heating unit 52 is installed in the
second tank 41, any structure for cooling the first refrigerant of
the first tank 21 and heating the first refrigerant of the second
tank 41 is possible. An unexplained reference numeral 57 denotes a
fan.
[0060] An operation of the air conditioning system according to the
preferred embodiment of the present invention will be
explained.
[0061] As shown in FIG. 2, the second refrigerant that circulates
on the heat source cycle 2 is compressed by the compressor 51 at
the time of a cooling operation. Then, the refrigerant passes
through the first four-way valve 53, the outdoor heat exchanger 55,
the second four-way valve 61, the heating unit 52, the outdoor
expansion valve 63, the cooling unit 54, the second four-way valve
61, the first four-way valve 53, and the accumulator 59, and then
is introduced into the compressor 51. The above circulation process
is repeatedly performed.
[0062] The controller 65 closes the heating line switching valve
49, but opens the cooling line switching valve 45. Accordingly, the
first liquid refrigerant stored in the second tank 41 is introduced
into the indoor unit 11 through the cooling line 43 and the inlet
side refrigerant line 11b of the indoor unit 11. The first liquid
refrigerant introduced into the indoor unit 11 passes through the
indoor expansion valve 15 and the indoor heat exchanger 13 thus to
be expanded and heat-exchanged. Then, the first liquid refrigerant
absorbs latent heat, and thereby cools the indoor room.
[0063] A first gaseous refrigerant vaporized after passing through
the indoor expansion valve 15 is introduced into the first tank 21
via the outlet side refrigerant line 11b of the indoor unit 11.
Then, the first gaseous refrigerant is cooled by the cooling unit
54, depressurized, condensed into a first liquid refrigerant, and
then is disposed on the diaphragm 23.
[0064] When a certain amount of the first liquid refrigerant is
stored in the lower space 21b of the first tank 21 by a pressure
difference that will be later explained, the refrigerant level
sensor 28 detects the first liquid refrigerant.
[0065] The controller 65 opens the switching valves 33 and 37, and
opens the connection line 31 and the pressure equalizing line 35,
thereby feeding back the first liquid refrigerant stored in the
lower space 21b to the second tank 41.
[0066] Since the second tank 41 is positioned to be lower than the
first tank 21, the first liquid refrigerant is fed-back to the
second tank 41 from the first tank 21 by a gravitation
difference.
[0067] The first gaseous refrigerant of the second tank 41 is
introduced into the lower space 21b of the first tank 21 through
the pressure equalizing line 35. Then, when the controller 65
closes the connection line 31 and the pressure equalizing line 35,
the first gaseous refrigerant introduced into the lower space 21b
of the first tank 21 loses its heat by the first liquid refrigerant
stored in the upper space 21a of the first tank 21 thereby to be
condensed into a first liquid refrigerant. Under the state, a
pressure difference between the upper space 21a and the lower space
21b of the first tank 21 is generated. Accordingly, the first
liquid refrigerant disposed on the diaphragm 23 in the upper space
21a is introduced into the lower space 21b of the first tank 21
through the first liquid refrigerant line 25. The first liquid
refrigerant stored in the lower space 21b of the first tank 21 is
fed-back to the second tank 41 in the same manner as the
aforementioned manner.
[0068] The first liquid refrigerant fed-back to the second tank 41
thus to be stored in the lower space 41b of the second tank 41 is
introduced into the indoor unit 11 through the cooling line 43.
Then, the first liquid refrigerant passes through the indoor
expansion valve 15 and the indoor heat exchanger 13 thus to be
expanded and heat-exchanged, thereby cooling the indoor room.
[0069] The first gaseous refrigerant is introduced into the first
tank 21 via the outlet side refrigerant line 11b of the indoor unit
11. Then, the first gaseous refrigerant is cooled by the cooling
unit 54, depressurized, condensed into a first liquid refrigerant,
and then is disposed on the diaphragm 23 of the first tank 21. The
above circulation process is repeatedly performed.
[0070] As shown in FIG. 4, the second refrigerant that circulates
on the heat source cycle 2 is compressed by the compressor 51 at
the time of a heating operation. Then, the refrigerant passes
through the first four-way valve 53, the second four-way valve 61,
the heating unit 52, the outdoor expansion valve 63, the cooling
unit 54, the second four-way valve 61, the outdoor heat exchanger
55, the first four-way valve 53, and the accumulator 59, and then
is introduced into the compressor 51. The above circulation process
is repeatedly performed.
[0071] The controller 65 closes the switching valve 45, but opens
the switching valve 49. Accordingly, the first gaseous refrigerant
stored in the second tank 41 is introduced into the indoor unit 11
through the heating line 47 and the inlet side refrigerant line 11a
of the indoor unit 11. The first gaseous refrigerant introduced
into the indoor unit 11 passes through the indoor expansion valve
15 and is heat-exchanged by the indoor heat exchanger 13, thereby
heating the indoor room.
[0072] The first gaseous refrigerant having passed through the
indoor heat exchanger 13 is introduced into the first tank 21 via
the outlet side refrigerant line 11a of the indoor unit 11. Then,
the first gaseous refrigerant is cooled by the cooling unit 54,
depressurized, condensed into a first liquid refrigerant, and then
is disposed on the diaphragm 23 of the first tank 21.
[0073] The first liquid refrigerant disposed on the diaphragm 23
inside the upper space 21a is introduced into the lower space 21b
of the first tank 21 by the aforementioned pressure difference
between the upper space 21a and the lower space 21b. When a certain
amount of the first liquid refrigerant is stored in the lower space
21b, the controller 65 feeds back the first liquid refrigerant
inside the lower space 21b of the first tank 21 to the second tank
41.
[0074] The first liquid refrigerant fed-back to the second tank 41
thus to be stored in the lower space 41b of the second tank 41 is
introduced into the indoor unit 11 through the heating line 47.
Then, the first liquid refrigerant passes through the indoor
expansion valve 15 and the indoor heat exchanger 13 thus to
heat-exchanged, thereby heating the indoor room.
[0075] The first gaseous refrigerant having passed through the
indoor heat exchanger 13 is introduced into the upper space 21a of
the first tank 21 through the outlet side refrigerant line 11a of
the indoor unit 11. Then, the first gaseous refrigerant is cooled
by the cooling unit 54, depressurized, condensed into a first
liquid refrigerant, and then is disposed on the diaphragm 23 of the
first tank 21.
[0076] As aforementioned, in the present invention, the first
liquid refrigerant stored in the first tank is fed-back to the
second tank without passing through a middle tank. Accordingly, a
height difference between the first tank and the second tank is
decreased, thereby simplifying an entire structure of the air
conditioning system, facilitating to install the air conditioning
system, and reducing a fabrication cost.
[0077] Furthermore, in the present invention, since the first
refrigerant is fed-back not only by the height difference between
the first tank and the second tank but also by the diaphragm
installed in the first tank, an amount of the first refrigerant
stored in the first tank and the second tank is more decreased than
in the conventional art.
[0078] As the present invention may be embodied in several forms
without departing from the spirit or essential characteristics
thereof, it should also be understood that the above-described
embodiments are not limited by any of the details of the foregoing
description, unless otherwise specified, but rather should be
construed broadly within its spirit and scope as defined in the
appended claims, and therefore all changes and modifications that
fall within the metes and bounds of the claims, or equivalence of
such metes and bounds are therefore intended to be embraced by the
appended claims.
* * * * *