[0001] The present disclosure relates to an air conditioner.
[0002] In general, air conditioners are apparatuses for cooling/heating an indoor space
or purifying air using a refrigerant cycle including a compressor, condenser, an expansion
mechanism, and an evaporator.
[0003] Air conditioners are classified into air conditioner in which a single indoor unit
is connected to a single outdoor unit and multi-type air conditioners in which a plurality
of indoor units are connected to one or more outdoor units to provide the effect of
a plurality of air conditioners.
[0004] The present invention provides an air conditioner according to claim 1. Preferred
embodiments are defined in the dependent claims.
[0005] In one embodiment, the air conditioner comprises an indoor unit; and an outdoor unit,
wherein the outdoor unit comprises: at least one compressor; an outdoor heat exchanger;
a supercooling unit configured to supercool a refrigerant; a first refrigerant pipe
allowing the supercooling unit to communicate with a suction side of the at least
one compressor; a first valve disposed at the first refrigerant pipe; a second refrigerant
pipe connecting the at least one compressor to the first refrigerant pipe; and a second
valve disposed at the second refrigerant pipe, wherein, in a first refrigerant flow
mode, a refrigerant flowing into the supercooling unit is introduced into the at least
one compressor through the second refrigerant pipe, and in a second refrigerant flow
mode, a refrigerant compressed by the at least one compressor is discharged into the
second refrigerant pipe.
[0006] 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.
[0007] Fig. 1 is a view illustrating a refrigerant cycle of an air conditioner according
to an embodiment.
[0008] Fig. 2 is a view illustrating a flow of a refrigerant when an air conditioner is
operate in a normal mode according to an embodiment.
[0009] Fig. 3 is a view illustrating a flow of a refrigerant when an air conditioner is
operated in an injection mode according to an embodiment.
[0010] Fig. 4 is a view illustrating a flow of a refrigerant when an air conditioner is
operated in a refrigerant bypass mode according to an embodiment.
[0011] Hereinafter, exemplary embodiments of the present disclosure will be described with
reference to the accompanying drawings. Regarding the reference numerals assigned
to the elements in the drawings, it should be noted that the same elements will be
designated by the same reference numerals, wherever possible, even though they are
shown in different drawings. Also, in the description of embodiments, detailed description
of well-known related structures or functions will be omitted when it is deemed that
such description will cause ambiguous interpretation of the present disclosure.
[0012] Also, in the description of embodiments, terms such as first, second, A, B, (a),
(b) or the like may be used herein when describing components of the present invention.
Each of these terminologies is not used to define an essence, order or sequence of
a corresponding component but used merely to distinguish the corresponding component
from other component(s). It should be noted that if it is described in the specification
that one component is "connected," "coupled" or "joined" to another component, the
former may be directly "connected," "coupled," and "joined" to the latter or "connected",
"coupled", and "joined" to the latter via another component.
[0013] Fig. 1 is a view illustrating a refrigerant cycle of an air conditioner according
to an embodiment.
[0014] Referring to Fig. 1, an air conditioner according to an embodiment may include an
outdoor unit 10 and an indoor unit 20 connected to the outdoor unit 10 through a refrigerant
pipe.
[0015] The indoor unit 20 includes a plurality of indoor units 21 and 22. For convenience
of description, although one outdoor unit is connected to two indoor units in the
current embodiment, the present disclosure is not limited to the number of indoor
unit and outdoor unit. That is, two or more indoor units may be connected to two or
more outdoor units or one indoor unit may be connected to one outdoor unit.
[0016] The outdoor unit 10 includes a compression unit 110 for compressing a refrigerant
and an outdoor heat exchanger 130 in which outdoor air is heat-exchanged with the
refrigerant.
[0017] The compression unit 110 may include one or more compressors. In the current embodiment,
the compression unit 110 including a plurality of compressors 111 and 112 will be
described as an example. A portion of the plurality of compressors 111 and 112 may
be an inverter compressor 111 having variable capacity and the other portion may be
a constant-speed compressor 112. Alternatively, the whole compressors 111 and 112
may be the constant-speed compressors or the inverter compressors. The plurality of
compressors 111 and 112 may be disposed in parallel. A portion of the plurality of
compressors 111 and 112 or the whole compressors 111 and 112 may be operated according
to the capacity of the indoor unit 20.
[0018] A discharge side pipe of each of the compressors 111 and 112 includes an individual
pipe 115 and a joint pipe 116. That is, the individual pipe 115 of each of the compressors
111 and 112 is jointed to the joint pipe 116. Oil separators 113 and 114 for separating
oil from the refrigerant may be disposed on the individual pipe 115. The oil separated
by the oil separators 113 and 114 may return to an accumulator 135 or each of the
compressors 111 and 112.
[0019] The joint pipe 116 is connected to a four-way valve 120 for switching a flow of the
refrigerant. The four-way valve 120 is connected to the outdoor heat exchanger 130
through a connection pipe 122. Also, the four-way valve 120 may be connected to the
accumulator 135, and the accumulator 135 may be connected to the compression unit
110.
[0020] The outdoor heat exchanger 130 includes a first heat exchanger part 131 and a second
heat exchanger part 132. The first and second heat exchanger parts 131 and 132 may
be independent heat exchangers separated from each other or a heat exchanger divided
into two parts in a single outdoor heat exchanger based on a refrigerant flow. The
first and second heat exchanger parts 131 and 132 may be horizontally or vertically
disposed with respect to each other. Also, the first and second heat exchanger parts
131 and 132 may have the same thermal capacity or capacities different from each other.
[0021] The refrigerant within the outdoor heat exchanger 130 may be heat-exchanged with
outdoor air blowing by a fan motor assembly 140 (including an outdoor fan and a fan
motor). The fan motor assembly may be provided in one or plurality. For example, Fig.
1 illustrates on outdoor fan motor assembly.
[0022] The outdoor unit 10 further includes an outdoor expansion mechanism 140. The outdoor
expansion mechanism 140 does not expand a refrigerant when the refrigerant passing
through the outdoor heat exchanger 130 passes, but expands a refrigerant when the
refrigerant which does not pass through the outdoor heat exchanger 130 passes.
[0023] The outdoor expansion mechanism 140 includes a first outdoor expansion valve 141
connected to the first heat exchanger part 131 and a second outdoor expansion valve
142 connected to the second heat exchanger part 132. Also, the first check valve 143
is parallely disposed with respect to the first outdoor expansion valve 141, and the
second check valve 144 is parallely disposed with respect to the second outdoor expansion
valve 142.
[0024] The refrigerant expanded by the first outdoor expansion valve 141 may flow into the
first heat exchanger part 131, and the refrigerant expanded by the second outdoor
expansion valve 142 may flow into the second heat exchanger part 132. For example,
each of the outdoor expansion valves 141 and 142 may be an electronic expansion valve
(EEV).
[0025] A bypass pipe unit is connected to the joint pipe 116. The bypass pipe unit connects
each of the heat exchanger parts 131 and 132 to each of the outdoor expansion valves
141 and 142. The bypass pipe unit may include a common pipe 150 connected to the joint
pipe 116 and first and second bypass pipes 151 and 152 branched from the common pipe
150. The first bypass pipe 151 is connected to a pipe connecting the first heat exchanger
part 131 to the first outdoor expansion valve 141, and the second bypass pipe 152
is connected to a pipe connecting the second heat exchanger part 132 to the second
outdoor expansion valve 142.
[0026] Also, a first bypass valve 153 is disposed in the first bypass pipe 151, and a second
bypass valve 154 is disposed in the second bypass pipe 152. For example, each of the
bypass valves 153 and 154 may be a solenoid valve through which a flow rate is adjustable.
For another example, the common pipe may be omitted in the bypass pipe unit, and the
first and second bypass pipes 151 and 152 may be connected to the joint pipe.
[0027] The bypass valves 153 and 154 may be opened during a heating operation. When the
bypass valves 153 and 154 are opened, a high-temperature refrigerant compressed by
the compression unit 110 may flow into the bypass pipes 151 and 152. When the high-temperature
flows into the bypass pipes 151 and 152, frosts on the outdoor heat exchanger 130
may be removed by the high-temperature refrigerant.
[0028] The outdoor expansion mechanism 140 may be connected to a supercooler 160 through
a liquid pipe 34. A supercooling pipe 162 for bypassing the refrigerant passing through
the supercooler 160 into the supercooler 160 is connected to the liquid pipe 34. Since
a structure of the supercooler 160 and a connection relationship between the pipes
may be realized by a previously well known structure, their detailed descriptions
will be omitted. A supercooling valve 164 which adjusts a flow rate of the refrigerant
and expands the refrigerant is disposed in the supercooling pipe 162. The supercooling
valve 164 may adjust a flow rate of the refrigerant flowing into a first refrigerant
pipe 170 that will be described later.
[0029] In the current embodiment, the supercooler 160, the supercooling pipe 162, and the
supercooling valve 164 supercool a refrigerant. Thus, the supercooler 160, the supercooling
pipe 162, and the supercooling valve 164 may be commonly called a supercooling unit.
[0030] The first refrigerant pipe 170 communicating with the supercooling pipe 162 and connected
to the accumulator 135 is connected to the supercooler 160. For example, the first
refrigerant pipe 170 may be connected to a pipe 121 connecting the four-way valve
120 to the accumulator 135. Also, a first valve 172 is disposed in the first refrigerant
pipe 170. For example, the first valve 172 may be a solenoid valve. Although the first
refrigerant pipe 170 is connected to a pipe 121 connected to the accumulator 135 in
the current embodiment, the present disclosure is not limited thereto. For example,
the first refrigerant pipe 170 may be connected to the accumulator 135 or between
the compression unit 110 and the accumulator 135. That is, in the current embodiment,
the first refrigerant pipe 170 may allow the supercooling unit to communicate with
a suction side of the compression unit 110.
[0031] A second refrigerant pipe is connected to the first refrigerant pipe 170. The second
refrigerant pipe includes a common pipe 180 and first and second branch pipes 182
and 184 branched from the common pipe 180. The first branch pipe 182 is connected
to the first compressor 111, and the second branch pipe 184 is connected to the second
compressor 112.
[0032] In the current embodiment, each of the compressors 111 and 112 may be a compressor
which enables the refrigerant to be compressed in multi-stages. Also, each of the
branch pipes 182 and 184 may communicate with a specific compression chamber (a compression
chamber in which a refrigerant compressed more than once is introduced) of a plurality
of compression chambers. For example, in case where the compressor has two compression
chambers (here, a refrigerant compressed in a first compression chamber is compressed
again in a second compression), the each of the branch pipes 182 and 184 may communicate
with the second compression chamber. Also, in case where the compressor has three
or more compression chambers, each of the branch pipes 182 and 184 may communicate
with one of the second compression chamber and the next compression chamber. A lower-pressure
region is defined at a suction side of the compressor, and a high-pressure region
is defined at a discharge side of the compressor. A region in which each of the branch
pipes 183 and 185 is connected may be a middle-pressure region.
[0033] Also, a first branch valve 183 is disposed in the first branch pipe 182, and a second
branch valve 185 is disposed in the second branch pipe 184. For example, each of the
branch valves 183 and 185 may be a solenoid valve. The first and second branch valves
183 and 185 may be called a second valve in reference to the first valve 172.
[0034] For another example, a valve may be omitted in the branch pipe, and a valve may be
disposed in the common pipe.
[0035] For another example, each of the branch pipes 183 and 185 may be connected to the
first refrigerant pipe.
[0036] The outdoor unit 10 may be connected to the indoor unit 20 through a gas pipe 31
and the liquid pipe 34. The substrate 31 may be connected to the four-way valve 120,
and the liquid pipe 34 may be connected to the outdoor expansion mechanism 140. That
is, a pipe connected to both sides of the supercooler 160 may be called the liquid
pipe 34.
[0037] Each of the indoor units 21 and 22 may include indoor heat exchangers 211 and 221,
indoor fans 212 and 222, and indoor expansion mechanisms 213 and 223. For example,
each of the indoor expansion mechanisms 213 and 223 may be an EEV.
[0038] Hereinafter, a refrigerant flow within the air conditioner according to the embodiment
will be described.
[0039] An operation mode of the air conditioner may include a normal mode (a normal cooling
mode, a normal heating mode, or a third refrigerant flow mode), an injection mode
(or a first refrigerant flow mode), and a refrigerant bypass mode (a second refrigerant
flow mode). The above-described modes may be classified according to a flow direction
of the refrigerant.
[0040] Fig. 2 is a view illustrating a flow of a refrigerant when an air conditioner is
operated in a normal mode according to an embodiment. For example, Fig. 2 illustrates
a refrigerant flow when the air conditioner is operated in a cooling mode.
[0041] Referring to Fig. 2, when the air conditioner is operated in the normal cooling mode,
a high-temperature high-pressure refrigerant discharged from the compression unit
110 of the outdoor unit 10 may flow toward the outdoor heat exchanger 130 by switching
the refrigerant flow through the flow-way valve 120.
[0042] The refrigerant flowing toward the outdoor heat exchanger 130 is condensed while
flowing into each of the heat exchanger parts 131 and 132. Here, in the normal cooling
mode of the air conditioner, the bypass valves 153 and 154 and the outdoor expansion
valves 141 and 142 are closed.
[0043] Thus, the refrigerant discharged from the compression unit 110 does not pass through
each of the bypass pipes 151 and 152. Also, the refrigerant discharged from each of
the heat exchanger parts 131 and 132 passes through each of the check valves 143 and
144.
[0044] Then, the condensed refrigerant flows into the supercooler 160. A portion of the
refrigerant passing through the supercooler 160 is expanded by the supercooling valve
164 while flowing into the supercooling pipe 162. The refrigerant expanded by the
supercooling valve 164 is introduced into the supercooler 160 and heat-exchanged with
the condensed refrigerant flowing along the liquid pipe 34.
[0045] According to the current embodiment, the refrigerant flowing along the supercooling
pipe 162 may drop in temperature and pressure while passing through the supercooling
valve 164. Thus, the refrigerant passing through the supercooling valve 164 has a
temperature relatively less than that of the refrigerant flowing into the liquid pipe
34. Thus, the condensed refrigerant is supercooled while passing through the supercooler
160. As the condensed refrigerant is supercooled, a low-temperature refrigerant may
be introduced into the indoor heat exchanger. Thus, a quantity of heat absorbed from
the indoor air may further increase to improve the overall cooling performance of
the air conditioner.
[0046] Here, in case where the air conditioner is operated in a normal heating mode, the
refrigerant may be supercooled also. Here, the supercooled refrigerant is introduced
into the outdoor heat exchanger. Thus, the heating performance of the air conditioner
may be improved.
[0047] The refrigerant within the supercooling pipe 162 passes through the supercooler 160
to flow into the first refrigerant pipe 170. Here, in the normal cooling mode of the
air conditioner, the first valve 172 is opened, and the each of the branch valves
183 and 185 is closed (which have the same state in the normal heating mode). Thus,
the refrigerant introduced into the supercooling pipe 162 is introduced into the accumulator
135 without being bypassed to each of the compressors 111 and 112.
[0048] The refrigerant flowing into the liquid pipe 34 is introduced into each of the indoor
units 21 and 22. The refrigerant introduced into each of the indoor units 21 and 22
is introduced into each of the indoor heat exchangers 211 and 221 after the refrigerant
is expanded by the indoor expansion mechanisms 213 and 223. The refrigerant is evaporated
while flowing into each of the indoor heat exchangers 211 and 221 and then is moved
into the outdoor unit 10 along the gas pipe 31. Then, the refrigerant is introduced
into the accumulator 135 via the four-way valve 120. A gaseous refrigerant of the
refrigerant introduced into the accumulator 135 is introduced into the compression
unit 110.
[0049] Fig. 3 is a view illustrating a flow of a refrigerant when an air conditioner is
operated in an injection mode according to an embodiment. For example, Fig. 3 illustrates
a refrigerant flow when the air conditioner is operated in the injection mode.
[0050] Referring to Fig. 3, the injection mode of the air conditioner is basically equal
to the normal cooling mode except for operations of the first valve 172 and the branch
valves 183 and 185. Thus, only the features different from those of the normal cooling
mode of the air conditioner will be described below.
[0051] In case where a differential pressure between a high pressure and a low pressure
of the compression unit 110 is equal to or greater than a reference pressure (the
high pressure is equal to or greater than the reference pressure or the low pressure
is equal to or less than the reference pressure) or a compression ratio (a ratio of
a high pressure to a low pressure) is equal to or less than a reference compression
ratio during the normal cooling mode of the air conditioner, the first valve 172 is
closed and each of the branch valves 183 and 185 are opened.
[0052] Thus, the refrigerant discharged from the supercooler 160 into the first refrigerant
pipe 170 is injected into each of the compressors 111 and 112 along the common pipe
180 and each of the branch pipes 182 and 184. Here, the refrigerant injected into
the compressors 111 and 112 has a middle pressure corresponding to a pressure between
a pressure of the discharge side of the compressor and a pressure of the suction side
of the compressor.
[0053] In the current embodiment, since the refrigerant having the middle pressure is injected
into each of the compressors 111 and 112, the differential pressure between the high
pressure and the low pressure of each of the compressors 111 and 112 is reduced. Thus,
the refrigerant discharged from the compressors 111 and 112 to flow into the condenser
(the outdoor heat exchanger during the cooling or the indoor heat exchanger during
the heating) increases in flow rate to improve the cycle performance.
[0054] In case where a differential pressure between a high pressure and a low pressure
is less than the reference pressure or a compression ratio (a ratio of a high pressure
to a low pressure) is greater than the reference compression ratio during the injection
mode of the air conditioner, the branch valves 183 and 185 are closed and the first
valve 172 is opened. Thus, the air conditioner is operated in the normal cooling mode.
[0055] Fig. 4 is a view illustrating a flow of a refrigerant when an air conditioner is
operated in a refrigerant bypass mode according to an embodiment. For example, Fig.
4 illustrates a refrigerant flow when the air conditioner is switched from the cooling
mode into the refrigerant bypass mode.
[0056] Referring to Fig. 4, the refrigerant bypass mode of the air conditioner is basically
equal to the normal cooling mode except for operations of the branch valves 183 and
185 and the supercooling valve 164. Thus, only the features different from those of
the normal cooling mode of the air conditioner will be described below.
[0057] In case where a cycle load increases (for example, a high pressure of the compression
unit is greater than the reference pressure) during the normal cooling mode of the
air conditioner, the supercooling valve 164 is closed and each of the branch valves
183 and 185 are opened.
[0058] Thus, the middle-pressure refrigerant compressed in a portion of the plurality of
compression chambers of each of the compressors 111 and 112 is bypassed to the branch
pipes 182 and 184. The refrigerant bypassed to the branch pipes 182 and 184 is introduced
into the first refrigerant pipe 170 via the common pipe 180. Then, the refrigerant
is introduced into the accumulator via the first refrigerant pipe 170.
[0059] According to the current embodiment, since the middle-pressure refrigerant within
the compressors 111 and 112 is discharged from the compressors 111 and 112 to flow
into the accumulator 135, a flow rate of each of the compressors 111 and 112 decreases.
Thus, the high-pressure refrigerant within the compressors 111 and 112 may decrease
in pressure to reduce the cycle load.
[0060] Also, according to the current embodiment, since the branch pipes serve as channels
for injecting the refrigerant as well as channels for discharging the middle-pressure
refrigerant, it is unnecessary to provide a separate pipe for bypassing the refrigerant.
Thus, the refrigerant cycle may be simplified in structure and manufacturing costs
may be reduced.
[0061] Also, since middle-pressure refrigerant is bypassed in the compressors 111 and 112,
a flow rate of the bypassed refrigerant is less than that of the bypassed high-pressure
refrigerant. Thus, it is unnecessary to provide a separate capillary in the second
refrigerant pipe.
[0062] In case where the cycle load decreases (for example, the compression unit has a high
pressure equal to or less than the reference pressure) during the refrigerant bypass
mode of the air conditioner, the branch valves 183 and 185 are closed and the supercooling
valve 164 is opened. Thus, the air conditioner is operated in the normal cooling mode.
[0063] Although the case in which the air conditioner is operated in the normal cooling
mode is described as example in the foregoing embodiment, the present disclosure is
not limited thereto. For example, the foregoing embodiment may be applied to a case
in which the air conditioner is operated in a normal heating mode. That is, the normal
heating mode of the air conditioner may be switched into the injection mode or the
refrigerant bypass mode.
[0064] Even though all the elements of the embodiments are coupled into one or operated
in the combined state, the present disclosure is not limited to such an embodiment.
That is, all the elements may be selectively combined with each other without departing
the scope of the invention. Furthermore, when it is described that one comprises (or
includes or has) some elements, it should be understood that it may comprise (or include
or has) only those elements, or it may comprise (or include or have) other elements
as well as those elements if there is no specific limitation. Unless otherwise specifically
defined herein, all terms including technical or scientific terms are to be given
meanings understood by those skilled in the art. Like terms defined in dictionaries,
generally used terms needs to be construed as meaning used in technical contexts and
are not construed as ideal or excessively formal meanings unless otherwise clearly
defined herein.
[0065] Although embodiments have been described with reference to a number of illustrative
embodiments thereof, it will be understood by those skilled in the art that various
changes in form and details may be made therein without departing from the scope of
the invention as defined by the appended claims. Therefore, the preferred embodiments
should be considered in descriptive sense only and not for purposes of limitation,
and also the technical scope of the invention is not limited to the embodiments. Furthermore,
is defined not by the detailed description of the invention but by the appended claims,
and all differences within the scope will be construed as being comprised in the present
disclosure.
1. An air conditioner comprising:
an indoor unit (20); and
an outdoor unit (10),
wherein the outdoor unit (10) comprises:
at least one compressor (111, 112);
an outdoor heat exchanger (130);
a supercooling unit (160) configured to supercool a refrigerant;
a first refrigerant pipe (170) allowing the supercooling unit (160) to communicate
with a suction side of the at least one compressor (111, 112);
a first valve (172) disposed at the first refrigerant pipe (170);
a second refrigerant pipe (180) connecting the at least one compressor (111, 112)
to the first refrigerant pipe (170); and
a second valve disposed at the second refrigerant pipe (180), wherein, in a first
refrigerant flow mode, a refrigerant flowing into the supercooling unit (160) is introduced
into the at least one compressor (111, 112) through the second refrigerant pipe (180),
and
in a second refrigerant flow mode, a refrigerant compressed by the at least one compressor
(111, 112) is discharged into the second refrigerant pipe (180).
2. The air conditioner according to claim 1, wherein, in a third refrigerant flow mode,
the refrigerant flowing into the supercooling unit (160) flows toward the suction
side of the at least one compressor (111, 112) via the first refrigerant pipe (170).
3. The air conditioner according to claim 2, wherein the air conditioner is configured
to perform the first refrigerant flow mode in a case where a differential pressure
between a high pressure and a low pressure of the at least one compressor (111, 112)
exceeds a reference pressure or a compression ratio of the high pressure to the low
pressure is equal to or less than a reference compression ratio.
4. The air conditioner according to claim 3, wherein, when a starting condition of the
first refrigerant flow mode is satisfied during the third refrigerant flow mode, the
air conditioner is configured to perform the first refrigerant flow mode.
5. The air conditioner according to claim 3, wherein, when a starting condition of the
second refrigerant flow mode is satisfied during the third refrigerant flow mode,
the air conditioner is configured to perform the second refrigerant flow mode.
6. The air conditioner according to claim 2, wherein, in the first refrigerant flow mode,
the first valve (172) is closed and the second valve is opened.
7. The air conditioner according to claim 2, wherein the air conditioner is configured
to perform the second refrigerant flow mode in a case where a high-pressure of the
at least one compressor (111, 112) exceeds a reference pressure.
8. The air conditioner according to claim 7, wherein the supercooling unit (160) further
comprises a supercooling valve (164) for adjusting a flow rate of the refrigerant
flowing into the first refrigerant pipe (170), and
in the second refrigerant flow mode, the supercooling valve (164) is closed and the
first (172) and second valves are opened.
9. The air conditioner according to claim 8, wherein, in the third refrigerant flow mode,
the supercooling valve (164) and the first valve (172) are opened and the second valve
is closed.
10. The air conditioner according to claim 1, wherein the at least one compressor (111,
112) comprises a plurality of compression chambers for compressing the refrigerant
in multi-stages, and
the second refrigerant pipe (180) communicates with one of the plurality of compression
chambers in which the refrigerant compressed more than once is introduced of the plurality
of compression chambers.
11. The air conditioner according to claim 1, wherein the compressor is provided in plurality,
and
the second refrigerant pipe comprises a common pipe (180) connected to the first refrigerant
pipe (170) and a plurality of branch pipes (182, 184) branched from the common pipe
(180) and respectively connected to the compressors (111, 112).
12. The air conditioner according to claim 11, wherein the second valve is disposed in
the common pipe.
13. The air conditioner according to claim 11, wherein the second valve (183, 185) is
disposed in each of the branch pipes (182, 184).
14. The air conditioner according to claim 1, wherein the compressor is provided in plurality,
the second refrigerant pipe comprises branch pipes connected to the first refrigerant
pipe (170) and each of the compressors (111, 112), and
the second valve is disposed in each of the branch pipes.