JPH0674598A - Multichamber type air conditioner - Google Patents

Abstract

PURPOSE:To prevent abnormal rise and fall of refrigerant pressure with an inexpensive specifications by operating an outdoor side heat exchanger at an upstream side of an air passage as a condenser and that at a downstream side as an evaporator at the time of room cooling small capacity operation, and operating an outdoor heat exchanger at an upstream side of an air flow as an evaporator and that at a downstream side as a condenser at the time of room heating small capacity operation. CONSTITUTION:In the case of room cooling small capacity operation, two-way valves 10a-10c, two-way valves 11a, 11c, and an outdoor side two-way valve 22 are opened, an outdoor side two-way valve 23 is closed, an indoor side expansion valve 7a is opened in response to an indoor load, an outdoor side heat exchanger 19 of an upstream side of an air passage of an outdoor side fan 24 is used as a condenser, and an outdoor side heat exchanger 18 of a downstream side is used as an evaporator. In the case of only room heating small capacity operation, the valve 10a is opened, the valves 10b, 10c are closed, the valves 11b, 11c, 22 are opened, the valve 23 is closed, the valve 72 is set to an opening responsive to an indoor load, the exchanger 19 is used as an evaporator, the exchanger 18 is used as a condenser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioner, and more particularly to a refrigeration cycle for a multi-room air conditioner in which cooling and heating can be freely selected for each indoor unit.

[0002]

2. Description of the Related Art In recent years, individual air conditioning has progressed in building air conditioning. For multiple rooms with different loads, an indoor unit is installed in each room and connected to one outdoor unit. Individual air-conditioning by type air conditioners has been promoted.

Conventionally, as this type of multi-room air conditioner,
For example, there is one disclosed in Japanese Patent Laid-Open No. 2-97858.

The conventional multi-room air conditioner of the above-mentioned publication will be described below with reference to the drawings.

In FIG. 5, reference numeral 1 is an outdoor unit of a multi-room air conditioner, which comprises a compressor 2, a three-way valve 3 as a three-way switching mechanism, an outdoor heat exchanger 4, and an outdoor expansion valve 5. . An indoor unit 6 includes an indoor expansion valve 7 and an indoor heat exchanger 8. Reference numeral 9 denotes a branch unit, which includes a high pressure side two-way valve 10 and a low pressure side two-way valve 11.

One of the indoor heat exchangers 8 communicates with the high pressure gas pipe 12 via the high pressure side two-way valve 10 and also communicates with the low pressure gas pipe 13 via the low pressure side two way valve 11. The high-pressure side two-way valve 10 and the low-pressure side two-way valve 11 are opened and closed to be switchably connected to the high-pressure gas pipe 12 or the low-pressure gas pipe 13.

The other of the indoor heat exchangers 8 is connected to the liquid pipe 14 via the indoor expansion valve 7. It should be noted that three indoor units 6 are connected in this conventional example, and the subscripts a, b, and c are added to distinguish them.

Next, the operation of the multi-room air conditioner having the above structure will be described. First, the case of only the cooling operation will be described. The flow of the refrigerant in this case is indicated by solid arrows, and the open / closed states of the valves are as follows. That is, the high pressure side two-way valve 10
Is closed, the low pressure side two-way valve 11 is open, and each indoor expansion valve 7 has an opening degree corresponding to each indoor load.

The refrigerant discharged from the compressor 2 is a three-way valve 3
Is condensed and liquefied in the outdoor heat exchanger 4 and is guided to the liquid pipe 14 through the outdoor expansion valve 5. And the indoor expansion valve 7
Through the low pressure side two-way valve 11 and then to the low pressure gas pipe 13. Then, it returns to the compressor 2 and performs a cooling operation.

Next, the case of only the heating operation will be described. The flow of the refrigerant in this case is indicated by a dashed arrow, and the open / closed state of each valve is as follows. That is, the high pressure side two-way valve 10 is open, the low pressure side two-way valve 11 is closed, and each indoor expansion valve 7 has an opening degree according to each indoor load.

The refrigerant discharged from the compressor 2 is passed through the high-pressure gas pipe 12 and the high-pressure side two-way valve 10 to each indoor heat exchanger 8
Is introduced into the liquid pipe 14 through the indoor expansion valve 7 and is decompressed to a low pressure two-phase state by the outdoor expansion valve 5, and enters the outdoor heat exchanger 4 to be evaporated and vaporized. . After that, it returns to the compressor 2 via the three-way valve 3 to perform the heating operation.

Next, the case of the cooling main operation in the cooling / heating mixed operation will be described with reference to FIG. Here, the operating state of each indoor unit 6 is as follows: indoor unit 6a, 6b ...
c ... Heating, and the open / closed state of each valve is as follows. That is, the high pressure side two-way valves 10a and 10b are closed, and the high pressure side two-way valve 1
0c is open, low-pressure side two-way valves 11a and 11b are open, low-pressure side two-way valve 11c is closed, and each indoor expansion valve 7 has an opening degree according to each indoor load.

A part of the refrigerant discharged from the compressor 2 is condensed and liquefied in the outdoor heat exchanger 4 via the three-way valve 3, and is guided to the liquid pipe 14 via the outdoor expansion valve 5. The remaining refrigerant is guided to the indoor heat exchanger 6c via the high-pressure gas pipe 12 and the high-pressure two-way valve 10c, where it is condensed and liquefied and flows into the liquid pipe 14 via the indoor expansion valve 7c. , Outdoor heat exchanger 4
It merges with the refrigerant that has passed through. And the indoor expansion valve 7
flows into the indoor heat exchangers 8a, 8b via a, 7b,
After evaporating and vaporizing each, the low pressure side two-way valves 11a, 11
It is led to the low pressure gas pipe 13 via b. Then, it returns to the compressor 2 and performs a cooling main operation.

Next, the case of the heating-main operation in the cooling / heating mixed operation will be described with reference to FIG. Here, the operating state of each indoor unit 6 is as follows: indoor unit 6a, 6b ... Heating, indoor unit 6
c ... Cooling is performed, and the open / closed state of each valve is as follows. That is, the high pressure side two-way valves 10a and 10b are opened, and the high pressure side two-way valve 1
0c is closed, low-pressure two-way valves 11a and 11b are closed, low-pressure two-way valve 11c is open, and each indoor expansion valve 7 has an opening according to each indoor load.

The refrigerant discharged from the compressor 2 is guided to the indoor heat exchangers 8a and 8b via the high pressure gas pipe 12 and the high pressure two-way valves 10a and 10b, where it is condensed and liquefied and expanded indoors. It flows into the liquid pipe 14 via the valves 7a and 7b. Liquid pipe 1
Part of the refrigerant of No. 4 flows into the indoor heat exchanger 8c via the indoor expansion valve 7c, is vaporized and evaporated, respectively, and then flows into the low pressure gas pipe 13 via the low pressure two-way valve 11c. The remaining refrigerant is decompressed by the outdoor expansion valve 5 to a low pressure two-phase state, enters the outdoor heat exchanger 4, and is evaporated and vaporized. After that, it flows into the low-pressure gas pipe 13 through the three-way valve 3, and the low-pressure side two-way valve 11
After merging with the refrigerant that has passed through c, it returns to the compressor 2 to perform heating-main operation.

[0016]

However, the above-mentioned conventional configuration has the minimum compressor capacity (5. 5) in the case of the cooling small capacity operation (for example, 2.3 kW indoor unit operation with respect to 29.1 kW outdoor unit operation). Evaporation capacity 2.3 kW compared to 8 kW)
Since it is small and the condensing capacity is as large as 29.1 kW, the evaporation pressure drops extremely. In addition, heating small capacity operation (for example, 2
(2.3 kW indoor unit operation for 9.1 kW outdoor unit)
In the case of, the condensation capacity is 2.3 kW, which is smaller than the minimum capacity of the compressor (equivalent to 5.8 kW), and the evaporation capacity is large, 29.1 kW, so the condensation pressure rises extremely. As described above, there is a drawback that the evaporation pressure extremely decreases and the condensation pressure extremely increases during the cooling small capacity operation and the heating small capacity operation, which threatens the reliability of the compressor and the stable operating state of the system.

The present invention solves the conventional problems, and controls the evaporation capacity and the condensation capacity according to the operating state of the indoor unit with inexpensive specifications to secure the reliability of the compressor and the stable operating state of the system. In addition, it is an object of the present invention to provide a multi-room air conditioner capable of freely cooling and heating each indoor unit.

[0018]

To achieve this object, the present invention provides a compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor heat exchanger, and a first outdoor expansion valve. A second outdoor expansion valve, a first outdoor two-way valve, a second outdoor two-way valve,
An outdoor unit, which comprises an outdoor fan, an outdoor unit in which the first outdoor heat exchanger is installed on the downstream side of the air flow path of the outdoor fan, and the second outdoor heat exchanger is installed on the upstream side, and an indoor expansion valve , A plurality of indoor units consisting of an indoor heat exchanger, a high-pressure two-way valve, consisting of a plurality of branch units installed low-pressure two-way valve, the outdoor unit and each branch unit is a high-pressure gas pipe,
The low pressure gas pipe and the liquid pipe are connected, the first passage of the four-way valve communicates with the high pressure gas pipe, and the second passage of the four-way valve communicates with the low pressure gas pipe. One communicates with the third passage of the four-way valve via the second outdoor two-way valve, and connects the pipe between the first outdoor heat exchanger and the second outdoor two-way valve. The first outdoor two-way valve communicates with the fourth passage of the four-way valve, and one of the second outdoor heat exchangers communicates with the third passage of the four-way valve, The other one of the second outdoor heat exchangers is configured to be merged and connected to the liquid pipe via the first and second outdoor expansion valves.

[0019]

With the above-described structure, the present invention operates the outdoor heat exchanger on the upstream side of the air passage of the outdoor fan as a condenser and the outdoor heat exchanger on the downstream side as an evaporator during a small capacity cooling operation. As a result, the evaporation pressure is prevented from decreasing and the outdoor heat exchanger on the upstream side of the air passage of the outdoor fan operates as an evaporator and the outdoor heat exchanger on the downstream side operates as a condenser during heating small capacity operation. As a result, the rise of the condensation pressure is prevented, a stable pressure state is maintained, and the reliability of the compressor and the stable operating state of the system are ensured.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The same parts as those of the prior art will be designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 15 denotes an outdoor unit of a multi-room air conditioner, which includes a compressor 16, a four-way valve 17, a first outdoor heat exchanger 18, a second outdoor heat exchanger 19, and a second outdoor heat exchanger 19. No. 1 outdoor expansion valve 20, second outdoor expansion valve 21, first outdoor two-way valve 22, second outdoor two-way valve 23, outdoor fan 2
It consists of 4 and.

The first outdoor heat exchanger 18 is located downstream of the air flow path of the outdoor fan 24, and the second outdoor heat exchanger 1 is located upstream thereof.
9, the first passage 17a of the four-way valve 17 communicates with the high-pressure gas pipe 12, the second passage 17b of the four-way valve 17 communicates with the low-pressure gas pipe 13, and one of the first outdoor heat exchangers 18 The first outdoor heat exchanger 18 is connected to one of the second outdoor heat exchangers 19 through the second outdoor two-way valve 23 so as to be joined and connected to the third passage 17c of the four-way valve 17. Between the second outdoor two-way valve 23 and the fourth passage 17d of the four-way valve 17 is connected via the first outdoor two-way valve 22, and the first and second outdoor heat exchangers are connected. The other one of 18 and 19 is joined and connected to the liquid pipe 14 via the first and second outdoor expansion valves 20 and 21.

Next, the operation in such a configuration will be described. First, the case of only the cooling operation will be described. The flow of the refrigerant in this case is indicated by solid arrows, and the open / closed states of the valves are as follows. That is, the high-pressure two-way valve 10 is closed, the low-pressure two-way valve 11 is open, the first outdoor two-way valve 22 is closed, the second outdoor two-way valve 23 is open, and each indoor expansion valve 7 Is an opening degree according to each indoor load.

The refrigerant discharged from the compressor 16 is condensed and liquefied by the first outdoor heat exchanger 18 and the second outdoor heat exchanger 19 via the four-way valve 17, and the first outdoor expansion valve 20. ，
It is guided to the liquid pipe 14 via the second outdoor expansion valve 21.
Then, after flowing into each indoor heat exchanger 8 through the indoor expansion valve 7 and evaporating and vaporizing, respectively, it returns to the compressor 16 through the low pressure side two-way valve 11 and the low pressure gas pipe 13 to perform the cooling operation. To do.

The case of only the cooling small capacity operation will be described. Here, the operating state of each indoor unit 6 is the indoor unit 6a.
... Cooling, indoor units 6b, 6c ... Stopped, and the flow of the refrigerant in this case is indicated by broken line arrows, and the open / closed state of each valve is as follows. That is, the high-pressure side two-way valve 10 is closed and the low-pressure side two-way valve 1
1 is open, the first outdoor two-way valve 22 is open, the second outdoor two-way valve 23 is closed, the indoor expansion valve 7a is opened according to the indoor load, and the indoor expansion valves 7b and 7c are It is fully closed.

The refrigerant discharged from the compressor 16 is condensed and liquefied by the second outdoor heat exchanger 19 via the four-way valve 17.
Part of the refrigerant that has passed through the second outdoor expansion valve 21 is the liquid pipe 14
Be led to. Then, it flows into the indoor heat exchanger 8a through the indoor expansion valve 7a, evaporates and vaporizes, and then flows into the low pressure gas pipe 13 through the low pressure two-way valve 11a. Further, the remaining refrigerant that has passed through the second outdoor expansion valve 21 flows into the first outdoor heat exchanger 18 via the first outdoor expansion valve 20,
After evaporating and vaporizing, the first outdoor two-way valve 22 and four-way valve 1
The refrigerant flows into the low pressure gas pipe 13 through 7, and merges with the refrigerant flowing in the indoor unit, and then returns to the compressor 16 to perform the cooling small capacity operation.

Therefore, the cooling small capacity operation (for example, the outdoor unit 2
When the minimum capacity of the compressor is 5.8 kW when the indoor unit is operated at 2.3 kW with respect to 9.1 kW, the second outdoor heat exchanger 19 on the upstream side of the air passage of the outdoor fan 24 is connected to the condenser and the downstream. By operating the first outdoor heat exchanger 18 on the side as an evaporator, the hot air after passing through the condenser and the evaporator can be heat-exchanged, so that the evaporation temperature is increased and the evaporation pressure is reduced. It is possible to prevent and secure a stable state in a cycle.

Next, the case of only the heating operation will be described with reference to FIG. The flow of the refrigerant in this case is indicated by solid arrows, and the open / closed states of the valves are as follows. That is, the high pressure side two-way valve 10 is open, the low pressure side two-way valve 11 is closed, the first outdoor two-way valve 22 is closed, the second outdoor two-way valve 23 is open, and each indoor expansion valve 7 is opened. Is an opening degree according to each indoor load.

The refrigerant discharged from the compressor 16 is guided to each indoor heat exchanger 8 via the high pressure gas pipe 12 and the high pressure two-way valve 10, where it is condensed and liquefied to the indoor expansion valve 7. Through the liquid pipe 14 and is depressurized to a low pressure two-phase state by the first outdoor expansion valve 20 and the second outdoor expansion valve 21, and the first outdoor heat exchanger 18 and the second outdoor It enters the heat exchanger 19 and evaporates and vaporizes. After that, it returns to the compressor 16 via the four-way valve 17 to perform the heating operation.

The case of only the heating small capacity operation will be described. Here, the operating state of each indoor unit 6 is the indoor unit 6a.
... Heating, indoor units 6b, 6c ... are stopped, and the flow of the refrigerant in this case is indicated by broken line arrows, and the open / closed state of each valve is as follows. That is, the high-pressure two-way valve 10a is open, the high-pressure two-way valves 10b and 10c are closed, the low-pressure two-way valve 11a is closed, the low-pressure two-way valves 11b and 11c are open, and the first outdoor two-way valve 22 is open, the second outdoor two-way valve 23 is closed, the indoor expansion valve 7a is opened according to the indoor load, and the indoor expansion valves 7b and 7c are fully closed.

A part of the refrigerant discharged from the compressor 16 is
It is guided to the indoor heat exchanger 8a via the high-pressure gas pipe 12 and the high-pressure two-way valve 10a, where it is condensed and liquefied and flows into the liquid pipe 14 via the indoor expansion valve 7a. The remaining refrigerant discharged from the compressor 16 is guided to the first outdoor heat exchanger 18 via the four-way valve 17 and the first outdoor two-way valve 22, where it is condensed and liquefied. The first outdoor expansion valve 20 flows into the liquid pipe 14, joins the refrigerant flowing through the indoor unit, and is decompressed by the second outdoor expansion valve 21 to a low-pressure two-phase state. It enters the exchanger 19 and is vaporized. After that, it returns to the compressor 16 through the four-way valve 17 to perform the heating operation and small capacity operation.

Therefore, the heating small capacity operation (for example, the outdoor unit 2
When the minimum capacity of the compressor is 5.8 kW when the indoor unit is operated at 2.3 kW with respect to 9.1 kW, the second outdoor heat exchanger 19 on the upstream side of the air passage of the outdoor fan 24 is connected to the evaporator and the downstream. By operating the first outdoor heat exchanger 18 on the side as a condenser, the low temperature air after passing through the evaporator can be heat-exchanged with the condenser, so that the condensing temperature is lowered and the condensing pressure is increased. It is possible to prevent and secure a stable state in a cycle.

Next, the case of the cooling main operation will be described with reference to FIG. Here, the operating state of each indoor unit 6 is indoor unit 6a, 6b ... Cooling, indoor unit 6c ... Heating, and the open / closed state of each valve is as follows. That is, the high pressure side two-way valves 10a, 1
0b is closed, high pressure two-way valve 10c is open, low pressure two-way valve 11
a and 11b are open, the low pressure side two-way valve 11c is closed, the first outdoor side two-way valve 22 is closed, the second outdoor side two-way valve 23 is open, and each indoor expansion valve 7 is loaded to each indoor load. It is the opening degree according to the above.

A part of the refrigerant discharged from the compressor 16 is
It is condensed and liquefied by the first outdoor heat exchanger 18 and the second outdoor heat exchanger 19 via the four-way valve 17, and is liquefied via the first outdoor expansion valve 20 and the second outdoor expansion valve 21. It is guided to the pipe 14. The remaining refrigerant flows into the high-pressure gas pipe 12, is guided to the indoor heat exchanger 8c via the high-pressure two-way valve 10c, and is condensed and liquefied there to flow through the indoor expansion valve 7c to the liquid pipe 14c. And joins the refrigerant flowing through the first outdoor heat exchanger 18 and the second outdoor heat exchanger 19.

Then, they flow into the indoor heat exchangers 8a and 8b through the indoor expansion valves 7a and 7b, and are vaporized and vaporized, respectively, and then guided to the low pressure gas pipe 13 through the low pressure two-way valves 11a and 11b. Return to compressor 16.

Next, the case of heating-main operation will be described with reference to FIG. Here, the operating state of each indoor unit 6 is indoor unit 6a, 6b ... Heating, indoor unit 6c ... Cooling, and the opening / closing state of each valve is as follows. That is, the high pressure side two-way valves 10a, 1
0b is open, high-pressure two-way valve 10c is closed, low-pressure two-way valve 11
a, 11b are closed, the low pressure side two-way valve 11c is open, the first outdoor side two-way valve 22 is closed, the second outdoor side two-way valve 23 is open, and each indoor expansion valve 7 is loaded to each indoor load. It is the opening degree according to the above.

The refrigerant discharged from the compressor 16 flows into the high pressure gas pipe 12 and is guided to the indoor heat exchangers 8a and 8b via the high pressure two-way valves 10a and 10b, where it is condensed and liquefied. It flows into the liquid pipe 14 through the indoor expansion valves 7a and 7b.

A part of the refrigerant in the liquid pipe 14 is used as the indoor expansion valve 7
It flows into the indoor heat exchanger 8c via c, evaporates and vaporizes, and then flows into the low pressure gas pipe 13 via the low pressure side two-way valve 11c. The remaining refrigerant is the first outdoor expansion valve 20,
The second outdoor expansion valve 21 reduces the pressure to a low-pressure two-phase state,
First outdoor heat exchanger 18, second outdoor heat exchanger 19
Enter and evaporate. After that, it flows into the low-pressure gas pipe 13 through the four-way valve 17, merges with the refrigerant that has passed through the low-pressure two-way valve 11c, and then returns to the compressor 16.

As described above, during the cooling small capacity operation, the outdoor heat exchanger upstream of the air passage of the outdoor fan is the condenser, the downstream outdoor heat exchanger is the evaporator, and the heating small capacity operation is By operating the outdoor heat exchanger on the upstream side as an evaporator and the outdoor heat exchanger on the downstream side as a condenser, it is possible to prevent the decrease in evaporation pressure and the increase in condensation pressure that have occurred in the past, and to improve the cycle The stable state can be secured.

[0040]

As is apparent from the above description, the present invention provides a compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor heat exchanger, a first outdoor expansion valve and a first outdoor expansion valve. The second outdoor expansion valve, the first outdoor two-way valve, the second outdoor two-way valve, and the outdoor fan. The first outdoor heat exchange is provided on the downstream side of the air flow path of the outdoor fan. Unit, an outdoor unit in which the second outdoor heat exchanger is installed on the upstream side, a plurality of indoor units including an indoor expansion valve and an indoor heat exchanger, a high-pressure two-way valve, and a low-pressure two-way valve The outdoor unit and each of the branch units are connected by a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe, and the first passage of the four-way valve is connected to the high-pressure gas pipe and the four-way valve. Of the first outdoor heat exchanger is connected to the low pressure gas pipe, and one of the first outdoor heat exchangers is connected via the second outdoor two-way valve. The four-way valve is connected to the third passage of the one-way valve, and the pipe between the first outdoor heat exchanger and the second outdoor two-way valve is connected via the first outdoor two-way valve. Of the second outdoor heat exchanger, one of the second outdoor heat exchangers is in communication with the third passage of the four-way valve, and the other one of the first and second outdoor heat exchangers is The liquid pipe is joined and connected via the first and second outdoor expansion valves.

Therefore, in the multi-room type air conditioner of the present invention, during the cooling small capacity operation, the outdoor heat exchanger on the upstream side of the air passage of the outdoor fan evaporates the outdoor heat exchanger on the downstream side. In the small capacity heating and heating operation, by operating the outdoor heat exchanger on the upstream side as an evaporator and the outdoor heat exchanger on the downstream side as a condenser, the decrease in evaporation pressure and the condensing pressure Ascent can be prevented and a stable cycle can be secured.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram showing a cooling operation state of a multi-room air conditioner according to a first embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram showing a heating operation state of the multi-room air conditioner of the same embodiment.

FIG. 3 is a refrigeration cycle diagram showing a cooling-main operation state of the multi-room air conditioner of the embodiment.

FIG. 4 is a refrigeration cycle diagram showing a heating-main operation state of the multi-room air conditioner of the same embodiment.

FIG. 5 is a refrigeration cycle diagram of a conventional multi-room air conditioner.

FIG. 6 is a refrigeration cycle diagram showing a cooling main operation state of a conventional multi-room air conditioner.

FIG. 7 is a refrigeration cycle diagram showing a heating-based operation state of a conventional multi-room air conditioner.

[Explanation of symbols]

 6 Indoor unit 7 Indoor expansion valve 8 Indoor heat exchanger 9 Branch unit 10 High pressure two-way valve 11 Low pressure two way valve 12 High pressure gas pipe 13 Low pressure gas pipe 14 Liquid pipe 15 Outdoor unit 16 Compressor 17 Four way valve 17a Four-way valve first passage 17b Four-way valve second passage 17c Four-way valve third passage 17d Four-way valve fourth passage 18 First outdoor heat exchanger 19 Second outdoor heat exchanger 20 First chamber Outer expansion valve 21 second outdoor expansion valve 22 first outdoor two-way valve 23 second outdoor two-way valve 24 outdoor fan

Claims (1)

[Claims] 1. A compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor heat exchanger, a first outdoor expansion valve, a second
Outdoor expansion valve, a first outdoor two-way valve, a second outdoor two-way valve, and an outdoor fan. The first outdoor heat is provided downstream of the outdoor fan in the air flow path. An exchanger, an outdoor unit in which the second outdoor heat exchanger is installed on the upstream side, a plurality of indoor units including an indoor expansion valve and an indoor heat exchanger, a high pressure two-way valve, and a low pressure two A plurality of branch units with a one-way valve installed, and the outdoor unit and each of the branch units are connected by a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe, and the first passage of the four-way valve , A second passage of the four-way valve communicates with the low-pressure gas pipe, and one of the first outdoor heat exchangers communicates with the third passage of the four-way valve via the second outdoor two-way valve. In addition, the pipe between the first outdoor heat exchanger and the second outdoor two-way valve and the fourth passage of the four-way valve are connected to the first outdoor It communicates via a two-way valve, one of the second outdoor heat exchangers communicates with the third passage of the four-way valve, and the other one of the first and second outdoor heat exchangers , The first and second outdoor expansion valves are joined together to the liquid pipe, and one of the indoor heat exchangers includes the high-pressure gas pipe or the low-pressure gas pipe and the high-pressure two-way valve, A multi-chamber air conditioner that is switchably connected by opening and closing the low-pressure side two-way valve, and the other one of the indoor heat exchangers is connected to the liquid pipe via the indoor expansion valve.