JP2022181077A - air conditioner - Google Patents

Abstract

To provide an air conditioner capable of suppressing the amount of refrigerant leaking to an indoor unit side.SOLUTION: An air conditioner includes: an outdoor unit having a compressor, an outdoor heat exchanger, and a first throttle device; an indoor unit having an indoor heat exchanger and a second throttle device; and a liquid-side piping and a gas-side piping connecting the outdoor unit and the indoor unit. The air conditioner includes: a second open/close device provided at a middle of the gas-side piping; a frist open/close device provided at a middle of the liquid-side piping; a first bypass piping bypassing the first open/close device; a first check valve provided in the first bypass piping and flowing refrigerant only in one direction on the side of the outdoor unit from the side of the indoor unit; and a control part controlling the first open/close device to take a closing operation when a refrigerant leakage sensor provided in the indoor unit detects refrigerant leakage.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to air conditioners.

Patent Literature 1 discloses an air conditioner that reduces the amount of refrigerant leaking into the room when refrigerant leakage occurs.
The disclosed air conditioner includes an outdoor unit having a compressor, a refrigerant flow switching device, an outdoor heat exchanger, and a first throttle device, an indoor unit having an indoor heat exchanger and a second throttle device, and and a refrigerant pipe to be connected to the refrigerant circuit. A first opening/closing device is provided in the refrigerant pipe between the first expansion device and the second expansion device, and a second opening/closing device is provided in the refrigerant pipe between the refrigerant flow switching device and the indoor heat exchanger. are provided.
This air conditioner suppresses the inflow of refrigerant from the outdoor unit side to the indoor unit side by closing the first opening and closing device and the second opening and closing device when refrigerant leakage is detected.

WO2017/203606

The present disclosure provides an air conditioner that can reduce the amount of leaking refrigerant when refrigerant leakage occurs on the indoor unit side.

An air conditioner according to the present disclosure includes an outdoor unit having a compressor, an outdoor heat exchanger, and a first expansion device, an indoor unit having an indoor heat exchanger and a second expansion device, and an outdoor unit and an indoor unit. A liquid side pipe and a gas side pipe to be connected are provided. A second opening/closing device is provided in the middle of the gas side pipe, and a first opening/closing device is provided in the middle of the liquid side pipe. The first opening/closing device is bypassed by a first bypass pipe, and the first bypass pipe is provided with a first check valve that allows the refrigerant to flow only in one direction from the indoor unit side to the outdoor unit side. Furthermore, the air conditioner according to the present disclosure includes a control unit that controls to close the first opening/closing device when a refrigerant leakage sensor provided in the indoor unit detects refrigerant leakage.

In the air conditioner according to the present disclosure, when a refrigerant leaks indoors, the refrigerant in the pipes closer to the indoor unit than both the first switchgear and the second switchgear flows into the outdoor unit through the first bypass pipe. can be made Therefore, it is possible to reduce the amount of leakage of the refrigerant on the indoor unit side.

1 shows a schematic configuration of a refrigerant circuit according to Embodiment 1. FIG. FIG. 4 shows an example of a branch shape of the first bypass pipe according to Embodiment 1. FIG. Schematic diagram showing an outline of each device in Embodiment 1 Flowchart showing the operation of the air conditioner in Embodiment 1

(Knowledge, etc. on which this disclosure is based)
At the time when the inventors came up with the present disclosure, in air conditioners, it was common to use a mildly flammable or combustible refrigerant such as R32 refrigerant as a refrigerant used in the refrigeration cycle. . Therefore, if a large amount of refrigerant used in air conditioners leaks indoors, there is a possibility of fire, and there is a technology to reduce the amount of refrigerant leakage when refrigerant leakage occurs on the indoor unit side. did.
This air conditioner includes an outdoor unit having a compressor, a refrigerant flow switching device, an outdoor heat exchanger, and a first throttle device, an indoor unit having an indoor heat exchanger and a second throttle device, and connecting them. and a refrigerant circuit. A first opening/closing device is provided in the refrigerant pipe between the first expansion device and the second expansion device, and a second opening/closing device is provided in the refrigerant pipe between the refrigerant flow switching device and the indoor heat exchanger. are provided. This air conditioner suppresses the inflow of refrigerant from the outdoor unit side to the indoor unit side by closing the first opening and closing device and the second opening and closing device when refrigerant leakage is detected. This reduces the amount of refrigerant leakage on the indoor unit side.

However, in the conventional technology, when both the first switchgear and the second switchgear are closed, the refrigerant flowing in the piping on the indoor unit side is more likely to flow on the indoor unit side than both the first switchgear and the second switchgear. remaining in the refrigerant pipe. Therefore, the inventors have discovered the problem that the entire amount of the isolated refrigerant may leak depending on the operating conditions, and have come to constitute the main subject of the present disclosure in order to solve the problem.
Accordingly, the present disclosure provides an air conditioner that can reduce the amount of leaking refrigerant when refrigerant leakage occurs on the indoor unit side.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially the same configurations may be omitted.
It should be noted that the accompanying drawings and the following description are provided to allow those skilled in the art to fully understand the present disclosure and are not intended to limit the claimed subject matter thereby.

(Embodiment 1)
Embodiment 1 will be described below with reference to FIGS. 1 to 4. FIG.

[1-1. Constitution]
[1-1-1. Configuration of refrigerant circuit]
FIG. 1 is a diagram showing a schematic configuration of a refrigerant circuit in an air conditioner 1 according to Embodiment 1 of the present disclosure.
According to this embodiment, the air conditioner 1 includes an outdoor unit 10, a plurality of (two in this embodiment) indoor units 30, and a gas side pipe 20 connecting the outdoor unit and the indoor unit. and a liquid side pipe 40.
Although FIG. 1 illustrates a refrigerant circuit in which two indoor units 30 are connected in parallel, only one indoor unit 30 or three or more indoor units 30 may be connected in parallel.

The outdoor unit 10 includes a compressor 11 , a refrigerant flow switching device 13 , an outdoor heat exchanger 15 and a first expansion device 17 .
The compressor 11 and the refrigerant flow switching device 13 are connected to each other by a discharge side pipe 12 through which the refrigerant compressed by the compressor 11 is discharged, and a suction side pipe 19 corresponding to the suction flow path of the compressor 11. there is One of the discharge-side pipe 12 and the suction-side pipe 19 communicates with the pipe connected to the outdoor heat exchanger 15 via the refrigerant flow switching device 13, and the other communicates with the gas-side pipe 20 connected to the indoor unit 30. communicated. The refrigerant flow switching device 13 switches the flow path of the refrigerant to change whether the air conditioner 1 performs the heating operation or the cooling operation.

The compressor 11 sucks the refrigerant from the suction side pipe 19 , compresses the sucked refrigerant into a high temperature and high pressure state, and then discharges it through the discharge side pipe 12 .
The outdoor heat exchanger 15 exchanges heat between the refrigerant and the outside air. During heating, the heat of the outside air is applied to the refrigerant to function as an evaporator that heats the refrigerant, and during cooling, the heat of the refrigerant is applied to the outside air to cool the refrigerant, functioning as a condenser.
The first expansion device 17 functions as a pressure reducing valve, and reduces the pressure of the high-pressure refrigerant during cooling to cool it.

Each indoor unit 30 includes an indoor heat exchanger 31 , a blower 33 , a second expansion device 35 and a refrigerant leakage sensor 37 .
The indoor heat exchanger 31 exchanges heat between the refrigerant and indoor air. The blower 33 sends the air after heat exchange by the indoor heat exchanger 31 from the indoor unit 30 into the room to adjust the indoor temperature. The opening degree of the second expansion device 35 is variable, and the room temperature is adjusted by adjusting the flow rate of the refrigerant flowing into each indoor unit 30 .
The refrigerant leakage sensor 37 is attached near the indoor heat exchanger 31 and detects refrigerant leaking out of the refrigerant circuit.

The gas side pipe 20 is provided with a second opening/closing device 25 . The second opening/closing device 25 is open during operation of the air conditioner 1 and shuts off the refrigerant flow in the gas-side pipe 20 by being closed.
In the present embodiment, the second opening/closing device 25 is provided at a portion where the gas side pipe 20 is not branched toward each indoor unit 30 , that is, near the outdoor unit 10 on the gas side pipe 20 .

The gas side pipe 20 includes a second bypass pipe 21 that bypasses the second opening/closing device 25 .
The second bypass pipe 21 is provided with a second check valve 23 . The second check valve 23 is installed so that the refrigerant can flow only in one direction from the indoor unit 30 side to the outdoor unit 10 side.

The liquid side pipe 40 connects the first expansion device 17 inside the outdoor unit 10 and the second expansion device 35 inside each indoor unit 30 .
The liquid side pipe 40 has a first opening/closing device 45 . The first opening/closing device 45 is open during operation of the air conditioner 1 and shuts off the refrigerant flow in the liquid-side pipe 40 by being closed.
In this embodiment, the first opening/closing device 45 is provided near the outdoor unit 10 on the liquid side pipe 40 .

The liquid side pipe 40 includes a first bypass pipe 41 that bypasses the first opening/closing device 45 . The first bypass pipe 41 is provided with a first check valve 43 . The first check valve 43 is installed so that the refrigerant can flow only in one direction from the indoor unit 30 side to the outdoor unit 10 side.

Here, the branch between the liquid-side pipe 40 and the first bypass pipe 41 is, for example, as shown in FIG. can also be formed so as to branch into
Also, the diameter of the first bypass pipe 41 can be set to be equal to or larger than the diameter of the liquid-side pipe 40 at the branch source, for example. When the first bypass pipe 41 is formed as in the above two examples, pressure loss is reduced when the refrigerant flows through the first bypass pipe 41 toward the outdoor unit 10 when detecting a refrigerant leak, which will be described later. .
Also, the first bypass pipe 41 and the liquid side pipe 40 may be arranged horizontally. In this case, the refrigerant is less likely to be trapped in the first bypass pipe 41 and the liquid-side pipe 40, and pressure loss when the refrigerant flows through the first bypass pipe 41 and the liquid-side pipe 40 can be suppressed.

Further, the liquid side pipe 40 is connected to the suction side pipe 19 by the outdoor bypass pipe 14 inside the outdoor unit 10 . A suction side opening/closing device 16 is provided in the middle of the outdoor bypass pipe 14 . The suction side opening/closing device 16 is closed during operation of the air conditioner 1 to block the flow of the refrigerant. Therefore, the outdoor bypass pipe 14 communicates the refrigerant between the liquid side pipe 40 and the suction side pipe 19 only while the suction side opening/closing device 16 is open when refrigerant leaks, which will be described later.

[1-1-2. Configuration of control unit]
Next, a control configuration in Embodiment 1 will be described.
FIG. 3 is a block diagram showing the control configuration of the air conditioner 1. As shown in FIG. However, for the convenience of explanation, portions that do not require communication with the control unit 50, such as the outdoor heat exchanger 15, are omitted. Moreover, in FIG. 3, only one indoor unit is shown.

In this embodiment, the controller 50 is housed inside the outdoor unit 10, as shown in FIG. The control unit 50 includes a processor such as CPU and MPU, and memory such as ROM and RAM. The control unit 50 is connected to each device shown in FIG. 3 by a wired or wireless communication line, and controls each connected device.
The control unit 50 is connected to each device of the outdoor unit 10, each indoor unit 30, the first opening/closing device 45, and the second opening/closing device 25, respectively.
The control unit 50 controls the compressor 11, the refrigerant flow switching device 13, and the first throttle device 17 in the outdoor unit 10 by reading and executing a control program stored in the memory. Also, the controller 50 is connected to an indoor unit controller 51 in each indoor unit 30 .

The indoor unit control unit 51 includes a processor such as CPU and MPU, and a memory such as ROM and RAM. The indoor unit control unit 51 in each indoor unit 30 is connected to the control unit 50, and the second expansion device 35, the blower 33, and the refrigerant leakage sensor 37 in each indoor unit 30 are wired or wirelessly connected. are connected by a communication line.
The indoor unit control unit 51 controls the rotation speed of the blower 33 and the opening degree of the second throttle device 35 by reading and executing a control program stored in the memory. Further, when the refrigerant leakage sensor 37 detects refrigerant leakage, the indoor unit controller 51 transmits a refrigerant leakage detection signal to the controller 50 .

[1-2. motion]
The operation and effect of the air conditioner 1 configured as described above will be described below with reference to a flow chart.
FIG. 4 is a flow chart showing the operation when refrigerant leakage is detected during operation of the air conditioner 1 .

As shown in FIG. 4, while the air conditioner 1 is in operation (step SA1), the controller 50 determines whether or not a refrigerant leakage detection signal is received from the indoor unit controller 51 (step SA2). Here, when the control unit 50 determines that it has acquired the refrigerant leakage detection signal, the control unit 50 reduces the operating frequency of the compressor 11 (step SA3).
Next, the controller 50 determines whether or not the operation mode of the air conditioner 1 is the heating operation (step SA4).

At this time, if the control unit 50 determines that the air conditioner 1 is in the heating operation (step SA4: YES), the control unit 50 closes the second opening/closing device 25 (step SA5). 1 The opening/closing device 45 is closed (step SA6).
When the air conditioner 1 is in the heating operation, in the first opening/closing device 45, the refrigerant is flowing from the indoor unit 30 side to the outdoor unit 10 side at the time of step SA4. On the other hand, in the second opening/closing device 25, the refrigerant is flowing from the indoor unit 30 side to the outdoor unit 10 side at the time of step SA4.

Therefore, by closing the second opening/closing device 25 and then closing the first opening/closing device 45, the refrigerant flows through the second opening/closing device 25 from the outdoor unit 10 side to the indoor unit 30 side. 1. The time for the opening/closing device 45 to flow from the indoor unit 30 side to the outdoor unit 10 side becomes longer.
As a result, after both steps SA5 and SA6 are executed, the amount of refrigerant isolated in the refrigerant pipe located closer to the indoor unit 30 than both the first opening/closing device 45 and the second opening/closing device 25 is reduced. be.

Furthermore, in the present disclosure, a first bypass pipe 41 is provided bypassing the first opening/closing device 45 . The first bypass pipe 41 is provided with a first check valve 43 that allows the refrigerant to flow only in one direction from the indoor unit 30 side to the outdoor unit 10 side.
After step SA6 is executed, the refrigerant that is closer to the indoor unit 30 than both the first opening/closing device 45 and the second opening/closing device 25 passes through the first check valve 43 to flow through the first bypass pipe 41 to the outdoor unit. 10 side can be passed. Therefore, the amount of refrigerant confined in the piping around the indoor unit 30 after step SA6 is further reduced.

Next, the controller 50 opens the suction side opening/closing device 16 (step SA7). As a result, the outdoor bypass pipe 14 connects two points: the liquid side pipe 40 closer to the outdoor unit 10 than both the first opening/closing device 45 and the first check valve 43, and the suction side pipe 19 of the compressor 11. become communicative.
The suction-side pipe 19 is the lowest pressure portion in the refrigerant circuit of the air conditioner 1 . Therefore, by communicating the suction side pipe 19 and the liquid side pipe 40 , the pressure on the outdoor unit 10 side of the liquid side pipe 40 is lower than both the first opening/closing device 45 and the first check valve 43 .
As a result, when viewed from the first check valve 43, the pressure difference between the low-pressure refrigerant in the liquid-side pipe 40 on the outdoor unit 10 side and the high-pressure refrigerant on the indoor unit 30 side increases. . Therefore, it becomes easier for the refrigerant to flow from the indoor unit 30 side to the outdoor unit 10 side in the first check valve 43 . Therefore, the amount of refrigerant isolated in the refrigerant pipe located closer to the indoor unit 30 than both the first opening/closing device 45 and the second opening/closing device 25 is further reduced.

On the other hand, when the control unit 50 determines that the air conditioner 1 is not in the heating operation (step SA4: NO), the control unit 50 first closes the first opening/closing device 45 (step SA8). Next, the controller 50 closes the second opening/closing device 25 (step SA9).
In this case, the air conditioner 1 is performing cooling operation. Therefore, the direction in which the refrigerant flows in the first opening/closing device 45 and the second opening/closing device 25 is the opposite direction to that when the air conditioner 1 is performing the heating operation.
Therefore, in the reverse order of the heating operation, step SA8 is executed first, and then step SA9 is executed. The amount of refrigerant sequestered in the located refrigerant piping is reduced.

After step SA7 or step SA9 is executed, controller 50 completely stops compressor 11 (step SA10). After that, the operation at the time of refrigerant leakage detection is ended (step SA11).

[1-3. effects, etc.]
As described above, in the present embodiment, the air conditioner 1 includes the outdoor unit 10 having the compressor 11, the outdoor heat exchanger 15, and the first expansion device 17, the indoor heat exchanger 31, and the second expansion device. and an indoor unit 30 having . In addition, the air conditioner 1 includes a liquid side pipe 40 and a gas side pipe 20 that connect the outdoor unit 10 and the indoor unit 30, a second opening and closing device 25 provided in the middle of the gas side pipe 20, and a liquid side and a first opening/closing device 45 provided in the middle of the pipe 40 . Furthermore, the air conditioner 1 includes a first bypass pipe 41 that bypasses the first opening/closing device 45, and a first bypass pipe 41 that is provided in the first bypass pipe 41 and allows the refrigerant to flow only in one direction from the indoor unit 30 side to the outdoor unit 10 side. A check valve 43 is provided. The air conditioner 1 includes a control unit 50 that controls the first opening/closing device 45 to close when the refrigerant leakage sensor 37 provided in the indoor unit 30 detects refrigerant leakage.

As a result, even after the refrigerant leaks during the heating operation of the air conditioner 1 and the first opening/closing device 45 and the second opening/closing device 25 are closed, the refrigerant is released to the outside through the first bypass pipe 41. It can flow to the machine 10 side. Therefore, the amount of refrigerant remaining on the indoor unit 30 side is reduced, and the amount of refrigerant leaking into the room can be reduced.

Further, as in the present embodiment, the air conditioner 1 includes the outdoor bypass pipe 14 formed to connect the liquid side pipe 40 and the suction side pipe 19 in the outdoor unit 10, and the outdoor bypass pipe 14 may be configured to include the suction side opening/closing device 16 .
As a result, refrigerant leakage occurs during heating operation of the air conditioner 1, and after the first opening/closing device 45 and the second opening/closing device 25 are closed, the suction side opening/closing device 16 is opened. A pressure gradient in the first bypass pipe 41 can be increased. Therefore, the refrigerant can easily flow to the outdoor unit 10 side, and the amount of refrigerant remaining on the indoor unit 30 side can be reduced, thereby reducing the amount of refrigerant leaking into the room.

Further, as in the present embodiment, the air conditioner 1 may be configured to include a second bypass pipe 21 that connects two points across the second opening/closing device 25 in the gas side pipe 20 . In this case, the second bypass pipe 21 includes a second check valve 23 that allows the refrigerant to flow only in one direction from the indoor unit 30 side to the outdoor unit 10 side.
As a result, the refrigerant leaks during cooling operation of the air conditioner 1, and even after the first opening/closing device 45 and the second opening/closing device 25 are closed, the refrigerant is allowed to flow through the second bypass pipe 21 to the outside of the room. It can flow to the machine 10 side. Therefore, even during cooling operation of the air conditioner 1, the amount of refrigerant remaining on the indoor unit 30 side is reduced, and the amount of refrigerant leaking into the room can be reduced.

(Other embodiments)
As described above, Embodiment 1 has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments with modifications, replacements, additions, omissions, and the like.
Therefore, other embodiments will be exemplified below.

In Embodiment 1, only one first opening/closing device 45 is provided near the outdoor unit 10 on the liquid side pipe 40 . Similarly, only one second opening/closing device 25 is provided near the outdoor unit 10 on the gas side pipe 20 .
However, the first opening/closing device 45 and the second opening/closing device 25 may be installed so as to block the refrigerant flow from the outdoor unit 10 side to the vicinity of the indoor unit 30 . Therefore, the arrangement of the first opening/closing device 45 and the second opening/closing device 25 is not limited to the vicinity of the outdoor unit 10 on both the liquid side pipe 40 and the gas side pipe 20 .
However, when the first opening/closing device 45 and the second opening/closing device 25 are arranged as in Embodiment 1, the first opening/closing device 45 and the second opening/closing device 25 are used one by one. Therefore, in the configuration described in Embodiment 1, the device cost and installation cost of the first switchgear 45 and the second switchgear 25 can be reduced, and the communication connection with the control unit 50 can be simplified.
In addition, one first opening/closing device 45 is provided for each pipe branched toward each indoor unit 30 of the liquid-side pipe 40, and a second opening/closing device 25 is provided for each indoor unit 30 of the gas-side pipe 20. It is good also as a structure which provides one for each branch piping.
According to this configuration, the volume in the refrigerant pipe including the leak point near the indoor unit 30, which is divided by the closing of both the first opening and closing device 45 and the second opening and closing device 25, is equal to that of the configuration in the first embodiment. becomes smaller than Therefore, the amount of refrigerant remaining on the side of the indoor unit 30 that may leak is reduced, and the amount of leakage of refrigerant on the side of the indoor unit 30 is further reduced.

In Embodiment 1, as an example of the operation when the control unit 50 of the air conditioner 1 receives the refrigerant leakage detection signal, when the control unit 50 determines that the air conditioner 1 is in heating operation, first It has been explained that after the second opening/closing device 25 is closed, the first opening/closing device 45 is closed and then the suction side opening/closing device 16 is opened.
However, in order to reduce the amount of refrigerant confined in the piping on the indoor unit 30 side, the closing operation of the second opening/closing device 25, the closing operation of the first opening/closing device 45, and the opening operation of the suction side opening/closing device 16 are performed. Just do it.
Therefore, the closing operation of the first opening/closing device 45 and the opening operation of the suction side opening/closing device 16 may be performed simultaneously, or the order in which they are performed may be changed.

When the closing operation of the first opening/closing device 45 is performed after the opening operation of the suction side opening/closing device 16, while the first opening/closing device 45 is open, the liquid-side pipe 40 is closed by the first opening/closing device 45. The pressure inside the pipe on the outdoor unit 10 side is reduced. This makes it easier for the refrigerant to flow from the indoor unit 30 side to the outdoor unit 10 side in the liquid-side pipe 40 than in the first embodiment. Therefore, the amount of refrigerant that may leak remaining on the indoor unit 30 side becomes smaller, and the amount of refrigerant leakage on the indoor unit 30 side is further reduced.
However, if the opening operation of the suction side opening/closing device 16 is performed after the closing operation of the first opening/closing device 45 as in Embodiment 1, the opening of the liquid side pipe 40 is performed after the first opening/closing device 45 is closed. The pressure inside the pipe on the side of the outdoor unit 10 is lower than the first opening/closing device 45 . That is, since the first opening/closing device 45 is closed while the pressure gradient in the liquid-side pipe 40 is small, the impact received when the first opening/closing device 45 is closed is reduced.

Further, in the operation of Embodiment 1, when the control unit 50 determines that the air conditioner 1 is in cooling operation, the first opening/closing device 45 is closed, then the second opening/closing device 25 is closed, and then the compression He explained that the plane 11 would be completely stopped.
However, in the present disclosure, the second opening/closing device 25 may be closed, and the suction side opening/closing device 16 may be opened, and then the compressor 11 may be completely stopped.
As a result, even when the control unit 50 receives the refrigerant leakage detection signal during the cooling operation of the air conditioner 1, the refrigerant pipe including the compressor 11 is closed when the compressor 11 is stopped. become. Therefore, even if the complete stop of the compressor 11 is delayed, an increase in the internal pressure of the pipe communicating with the discharge side pipe 12 of the compressor 11 can be suppressed. Thereby, failure of the air conditioner 1 can be suppressed.

However, when the opening operation of the suction side switchgear 16 is not executed during cooling operation as in the first embodiment, the pressure difference between the outdoor unit 10 side and the indoor unit 30 side in the gas side pipe 20 is It becomes larger than when the opening operation is performed. This makes it easier for the refrigerant to flow from the indoor unit 30 side to the outdoor unit 10 side. Therefore, the leakage amount of the refrigerant on the indoor unit 30 side is significantly reduced as compared with the case where step SA7 is executed.

Note that the above-described embodiment is for illustrating the technology in the present disclosure, and various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

It can be applied to an air conditioner having a switchgear for countermeasures against refrigerant leakage. Specifically, the present disclosure can be applied to an air conditioner or the like that closes a switchgear with refrigerant flowing when refrigerant leakage is detected.

1 Air conditioner 10 Outdoor unit 11 Compressor 12 Discharge side pipe 13 Refrigerant flow switching device 14 Outdoor bypass pipe 15 Outdoor heat exchanger 16 Suction side opening and closing device 17 First expansion device 19 Suction side pipe 20 Gas side pipe 21 Second Bypass pipe 23 Second check valve 25 Second opening/closing device 30 Outdoor unit 31 Indoor heat exchanger 33 Air blower 35 Second expansion device 37 Refrigerant leakage sensor 40 Liquid side pipe 41 First bypass pipe 43 First check valve 45 First Opening/closing device 50 control section 51 indoor unit control section

Claims (3)

an outdoor unit having a compressor, an outdoor heat exchanger, and a first expansion device;
an indoor unit having an indoor heat exchanger and a second expansion device;
a liquid side pipe and a gas side pipe that connect the outdoor unit and the indoor unit;
In an air conditioner comprising
a second opening/closing device provided in the middle of the gas side pipe;
a first opening/closing device provided in the middle of the liquid side pipe;
a first bypass pipe that bypasses the first opening/closing device;
a first check valve provided in the first bypass pipe and allowing the refrigerant to flow only in one direction from the indoor unit side to the outdoor unit side;
An air conditioner, comprising: a control unit that controls to close the first opening/closing device when refrigerant leakage is detected by a refrigerant leakage sensor provided in the indoor unit. The outdoor unit is
an outdoor bypass pipe that communicates between the first expansion device and the first opening/closing device of the liquid side pipe and the suction flow path of the compressor;
a suction side opening/closing device provided in the middle of the outdoor bypass pipe,
The air conditioner according to claim 1, wherein the control unit opens the suction side opening/closing device when closing the first opening/closing device. The gas side piping is
a second bypass pipe that bypasses the second opening/closing device;
A second check valve provided in the second bypass pipe and allowing the refrigerant to flow only in one direction from the indoor unit side to the outdoor unit side,
The air conditioner according to claim 1 or 2, wherein the control unit controls to close the second opening/closing device when the refrigerant leakage sensor detects refrigerant leakage.

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