JPH07318185A - Freezing apparatus - Google Patents

Abstract

PURPOSE:To direct a refrigerant to flow uniformly through a heat exchanger of each outdoor unit, and shave sensors. CONSTITUTION:There provided are a first outdoor unit 2A and a second outdoor unit 2B each of which includes a compressor 21, an outdoor heat exchanger 24, and an outdoor motor driven expansion valve 25. The outdoor units 2A, 2B are connected parallely with a main liquid line 4L, a main gas line 4G. An indoor heat exchanger 32 is provided, and a plurality of utilization units 3A, 3B are connected parallley with the main liquid line 41 and the main gas line 4G. A liquid stop valve V1 is provided on a liquid line 5LB on the side of the second outdoor unit 2B, and a gas stop, valve V2 is provided on the gas line 5GB. Further provided is a coupling gas line 10 having a coupling stop valve V4 for stopping a refrigerant flow when cooling operation of the second outdoor unit 2B is interrupted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus having a plurality of heat source units, and more particularly to measures for improving refrigerating operation efficiency.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner as a refrigeration system, as disclosed in Japanese Patent Laid-Open No. 4-208370, a plurality of indoor units are arranged in parallel with one outdoor unit by refrigerant pipes. There is a multi-type connected. The outdoor unit includes a compressor, a four-way switching valve, an outdoor heat exchanger, an outdoor electric expansion valve, and a receiver, while the indoor unit includes an indoor electric expansion valve and an indoor heat exchanger. Then, during the cooling operation, the refrigerant discharged from the compressor is condensed in the outdoor heat exchanger, decompressed by the indoor electric expansion valve, then evaporated in the indoor heat exchanger and circulated so as to return to the compressor, while the heating operation is performed. At times, the refrigerant discharged from the compressor is condensed in the indoor heat exchanger, decompressed by the outdoor electric expansion valve, evaporated in the outdoor heat exchanger, and circulated so as to return to the compressor. In the outdoor unit,
The capacity of the compressor is controlled according to the load of the indoor unit.

[0003]

In the above-mentioned air conditioner, since only one outdoor unit is conventionally provided, there are various types of capacities corresponding to the indoor load, that is, the number of connected indoor units. There was a problem that it was necessary to fabricate the outdoor unit. Then, when the indoor load and the capacity of the outdoor unit do not match, there is a problem that the capacity of the outdoor unit increases even though the indoor load is small. Therefore, it is conceivable to combine a plurality of outdoor units having different capacities, for example, two outdoor units in a multi-type. In that case, the capacity of the compressor of each outdoor unit may differ, and there is a problem of inefficiency. In other words, the compressor of the outdoor unit of 1 is 100%
The compressor of the other outdoor unit is 5
There is a case of operating at 0%, and if supercooling control is not performed during cooling operation, in an outdoor unit with a large refrigerant circulation amount, a flush occurs at the outlet side of the outdoor heat exchanger, and conversely, the refrigerant circulation amount. There is a problem that the supercooling becomes excessively large in the outdoor unit having a small number. Further, in the outdoor heat exchanger of each of the outdoor units, since a refrigerant corresponding to the capacity of the compressor flows, there is a problem that each outdoor unit requires a low pressure sensor or the like.

The present invention has been made in view of the above problems, and is intended to allow the refrigerant to flow evenly through the heat exchanger of each heat source unit and to share the sensor.

[0005]

Means for Solving the Problems In order to achieve the above object, the means taken by the present invention is one in which a gas side refrigerant pipe of a heat source side heat exchanger in each heat source unit can be connected by a connecting gas line. Is. Specifically, the means taken by the invention according to claim 1 is as follows. First, a compressor (21), one end of which is connected to the discharge side of the compressor (21) and the other end of which is a liquid line (5L).
A heat source side heat exchanger (24) connected to (A, 5LB), a plurality of heat source units (2A, 5GA, 5GB) connected to the gas side (5GA, 5GB) on the suction side of the compressor (21). 2B) is provided.
Then, the liquid lines (5LA, 5LB) and the gas lines (5LA) so that the heat source units (2A, 2B) are connected in parallel.
Main liquid line to which the outer ends of (GA, 5GB) are connected respectively
(4L) and the main gas line (4G) is provided, and has a use side expansion mechanism (33) and a use side heat exchanger (32), the main liquid line (4L) and the main gas line (4G) A plurality of utilization units (3A, 3B) connected in parallel with each other are provided. Furthermore, the above multiple heat source units (2A, 2B)
Liquid line (5LB) of at least one heat source unit (2B)
Is provided with a liquid opening / closing mechanism (V1) that is fully closed when the cooling operation of the heat source unit (2B) is stopped. In addition, both ends are connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B), and at least 1
When the cooling operation of the heat source unit (2B) is stopped, the connecting opening / closing mechanism (V
A connecting gas line (10) with 4) is provided.

Further, the means taken by the invention according to claim 2 is, as shown in FIG. 1, first, the compressor (21) and one end of which can be switched between the discharge side and the suction side of the compressor (21). Source side heat exchanger connected to the liquid line and the other end to the liquid line (5LA, 5LB)
(24) and has a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB), and a gas line (5GA, 5GB) on the discharge side and the suction side of the compressor (21). First connected to switchable
A heat source unit (2A) and a second heat source unit (2B) are provided. And each liquid line (5LA, 5LB) and each gas line so that each said heat source unit (2A, 2B) is connected in parallel.
(5GA, 5GB) is provided with a main liquid line (4L) and a main gas line (4G), which are connected to the outer ends thereof, respectively,
A plurality of utilization units (3A, 3B) having a utilization side heat exchanger (32) and connected in parallel to the main liquid line (4L) and the main gas line (4G) are provided. Further, the liquid line (5LB) on the second heat source unit (2B) side is provided with a liquid opening / closing means (V1) for closing the liquid line (5LB) when the operation of the second heat source unit (2B) is stopped, The gas line (5 GB) on the second heat source unit (2B) side is provided with the second heat source unit.
Gas switching mechanism (V2) that is fully closed when the heating operation of (2B) is stopped
Is provided. In addition, both ends are connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B), and at least one heat source unit (2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) that blocks the flow of the refrigerant to the stopped heat source unit (2B) when the cooling operation is stopped is provided.

In the means taken by the invention according to claim 3, as shown in FIG. 5, first, the compressor (21) and one end thereof can be switched between the discharge side and the suction side of the compressor (21). Source side heat exchanger connected to the liquid line and the other end to the liquid line (5LA, 5LB)
(24) and has a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB), and a gas line (5GA, 5GB) on the discharge side and the suction side of the compressor (21). First connected to switchable
A heat source unit (2A) and a second heat source unit (2B) are provided. Then, the main liquid line (4L) to which the outer ends of the liquid lines (5LA, 5LB) of the heat source units (2A, 2B) are respectively connected, and the gas line (5 of the first heat source unit (2A).
(GA) is provided with a main gas line (4G) to which the outer end side is connected, and has a use side heat exchanger (32), with respect to the main liquid line (4L) and the main gas line (4G). A plurality of utilization units (3A, 3B) connected in parallel are provided. Further, a branch line (5a) having one end connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in the first heat source unit (2A) is provided, and the main gas line (4G) is also provided. And the branch line (5a) are connected to each other, and have a constant high pressure passage (91) kept at a high pressure state and a constant low pressure passage (92) kept at a constant low pressure state, and the second heat source unit (2
The gas line (5 GB) on the B side is connected to the constant high pressure passage (91) so that the refrigerant can flow from the gas line (5 GB) toward the constant high pressure passage (91), and the second heat source unit (2B)
The gas line (5GB) on the side is such that the refrigerant always flows from the low pressure passage (92) toward the gas line (5GB).
A constant pressure circuit (9) connected to (92) is provided. In addition, the liquid line (5LB) on the second heat source unit (2B) side has a liquid line (5LB) when the operation of the second heat source unit (2B) is stopped.
A liquid opening / closing means (25) for closing the LB) is provided. In addition, both ends are respectively connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B), and when the cooling operation of at least one heat source unit (2B) is stopped,
A connecting gas line (10) having a connecting opening / closing mechanism (V4) for blocking the flow of the refrigerant to the stopped heat source unit (2B) is provided.

The means taken by the invention according to claim 4 is, as shown in FIGS. 6 and 7, firstly, a compressor (21),
The heat source side heat exchanger (24) having one end switchably connected to the discharge side and the suction side of the compressor (21) and the other end connected to the liquid lines (5LA, 5LB), and the liquid line (5LA , 5LB) and a heat source side expansion mechanism (25), and a high pressure passage (57a, 58a) that allows the refrigerant to flow in the discharge direction from the compressor (21) and the compressor.
Low pressure passage (57b, 58b) that allows refrigerant to flow in the suction direction of (21)
Provided with a plurality of heat source units (2A, 2B) whose base ends of gas lines (5GA, 5GB) branched to b) are switchably connected to the discharge side and the suction side of the compressor (21). Has been. Then, each liquid line (5LA, 5LB), each high pressure passage (57a, 58a) and each low pressure passage (57b, 58b) were connected so that each heat source unit (2A, 2B) was connected in parallel. A main liquid line (4L), a main high pressure gas line (4H) and a main low pressure gas line (4W) are provided, and the main liquid line (4L)
L) has a utilization side heat exchanger (32) connected to one end, and a utilization side expansion mechanism (33) provided between the utilization side heat exchanger (32) and the main liquid line (4L). Having the above-mentioned utilization side heat exchanger (32)
A plurality of utilization units (3, 3, ...) Connectably connected to the main high-pressure gas line (4H) and the main low-pressure gas line (4W) at the other end thereof are provided. In addition, the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in one heat source unit (2A) is connected to the gas side refrigerant of the heat source side heat exchanger (24) in the other heat source unit (2B). A connection opening / closing mechanism that allows the pipe (26) to communicate with each other and allows bidirectional refrigerant flow
A connecting gas line (10) having (V4) is provided.

In the means taken by the invention according to claim 5, as shown in FIG. 8, first, the compressor (21) and one end thereof can be switched between the discharge side and the suction side of the compressor (21). Source side heat exchanger connected to the liquid line and the other end to the liquid line (5LA, 5LB)
(24) and has a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB), and a high pressure passage (57a, 58a) that allows the refrigerant to flow in the discharge direction from the compressor (21). ) And a low pressure passage (57b, 58b) that allows the refrigerant to flow in the suction direction of the compressor (21), the base end of the gas line (5GA, 5GB) is the compressor (21).
A plurality of heat source units (2A, 2B) are provided that are switchably connected to the discharge side and the suction side. Then, each liquid line (5LA, 5LB), each high pressure passage (57a, 58a) and each low pressure passage (5) so that each heat source unit (2A, 2B) is connected in parallel.
Main liquid line (4L), main high-pressure gas line (4H) and main low-pressure gas line (4W) to which 7b and 58b) are respectively connected.
And the use side heat exchanger (32) whose one end is connected to the main liquid line (4L), and the use side heat exchanger (3
2) and the main liquid line (4L) has a utilization side expansion mechanism (33) provided between, the other end of the utilization side heat exchanger (32) is the main high pressure gas line (4H) and Main low pressure gas line
Multiple use units (3, 4W) switchably connected to (4W)
3,…) are provided. Furthermore, one end is connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in one heat source unit (2A), and the other end is connected to the main high pressure gas line (4).
H) and the main low-pressure gas line (4W), the high-pressure auxiliary passage (83) and the main low-pressure gas line (83) for allowing the refrigerant flow between the heat source unit (2A) and the main high-pressure gas line (4H) ( An auxiliary gas line (8a) having a low pressure auxiliary passage (84) that allows the refrigerant to flow between the heat source unit (2A) and the heat source unit (2A) is provided. In addition, the gas side refrigerant of the heat source side heat exchanger (24) in the other heat source unit (2B) to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in one heat source unit (2A) A connecting gas line (10) is provided, which is provided so that the pipes (26) communicate with each other and has a connecting opening / closing mechanism (V4) that allows bidirectional refrigerant flow.

Further, the means taken by the invention according to claim 6 is the invention according to claim 4 or 5, wherein one end communicates with the gas line (5GA) in one heat source unit (2A),
In addition, the other end is connected between the other heat source unit (2B) and the connection opening / closing mechanism (V4) in the connection gas line (10) and has a branch opening / closing mechanism (V27) that allows bidirectional refrigerant flow. A gas passage (10c) is provided. The means taken by the invention according to claim 7 is, in the invention according to any one of claims 4 to 6 above, connected between a main high pressure gas line (4H) and a main low pressure gas line (4W), A pressure equalizing passage (8c) having a pressure equalizing opening / closing mechanism (V30) for circulating and blocking the refrigerant from the main high pressure gas line (4H) to the main low pressure gas line (4W) is provided. Further, the means taken by the invention according to claim 8 is the liquid line (5LA, 5LB) and the main liquid line (4L) in the invention according to any one of claims 1 to 7 above.
A receiver (12) for connecting the liquid lines (5LA, 5LB) and the main liquid line (4L) is provided at the connecting portion.

[0011]

With the above construction, in the invention according to claim 1,
First, the high pressure gas refrigerant discharged from the compressor (21) of each heat source unit (2A, 2B) is condensed in the heat source side heat exchanger (24) to become a liquid refrigerant, and this liquid refrigerant is the main liquid line (4L). Join at. Particularly, in the invention according to claim 8, the refrigerant is the receiver (1
Merge at 2). After that, the liquid refrigerant is expanded to the use side expansion mechanism.
After being decompressed in (33), it is evaporated in the use side heat exchanger (32) to become a low pressure gas refrigerant, and this gas refrigerant is used in each gas line (5G
A, 5GB) and the compressor (2A, 2B) of each heat source unit (2A, 2B)
Returning to 1), this circulation operation is repeated to perform the cooling operation. When the cooling operation of the first heat source unit (2B) is stopped, the liquid opening / closing mechanism (V1) is closed to prevent the liquid refrigerant from accumulating. Further, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat-source units (2A, 2B) communicates with each other via the connecting gas line (10), and each heat-source-side heat exchanger ( 2
The circulation rate of the refrigerant flowing through 4) is almost even, and the COP (coefficient of performance) is improved.

Further, in the invention according to claim 2, first, during the cooling operation, the compressor of each heat source unit (2A, 2B)
The high pressure gas refrigerant discharged from (21) is the heat source side heat exchanger (24).
Is condensed into liquid refrigerant, which is the main liquid line.
Merge at (4L). Particularly, in the invention according to claim 8, the refrigerant merges at the receiver (12). After that, the liquid refrigerant is decompressed by the use side expansion mechanism or the like, then evaporated in the use side heat exchanger (32) to become a low pressure gas refrigerant, and this gas refrigerant is divided into each gas line (5GA, 5GB). The flow is returned to the compressor (21) of each heat source unit (2A, 2B), and this circulation operation is repeated.
Furthermore, during heating operation, each heat source unit (2A, 2B)
The high-pressure gas refrigerant discharged from the compressor (21) of (1) joins the main gas line (4G) and then flows to the usage units (3A, 3B). Then, this gas refrigerant is condensed in the utilization side heat exchanger (32) to become a liquid refrigerant, and this liquid refrigerant is the main liquid-liquid line.
(4L) to each heat source unit (2A, 2B) side liquid line (5LA, 5L
It is divided into B). Particularly, in the invention according to claim 8, the refrigerant is split in the receiver (12). Thereafter, this liquid refrigerant is decompressed by the heat source side expansion mechanism (25), and then the heat source side heat exchanger (24).
To become a low-pressure gas refrigerant, and each heat source unit (2A, 2A
Returning to the compressor (21) of B), this circulation operation is repeated. Then, when the heating operation in the second heat source unit (2B) is stopped, the gas opening / closing mechanism (V2) is closed, and the liquid opening / closing is performed when the cooling operation and the heating operation in the second heat source unit (2B) are stopped. The mechanism (V1) is closed to prevent the liquid refrigerant from accumulating in the stopped second heat source unit (2B), and the first heat source unit (2A) and the utilization unit (3A, 3
Prevent the shortage of the amount of refrigerant between B). In particular, the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B) communicates with each other through the connecting gas line (10), and during cooling operation and heating operation. In any of the above cases, the circulation amount of the refrigerant flowing through each heat source side heat exchanger (24) becomes substantially equal, and the COP (coefficient of performance) is improved.

Further, in the invention according to claim 3, the gas refrigerant flowing into the second heat source unit (2B) and the second heat source unit.
The gas refrigerant discharged from (2B) passes between the gas line (5GB) and the main gas line (4G) via the constant high pressure passage (91) and the constant low pressure passage (92) of the constant pressure circuit (9). It will flow. Therefore, the gas opening / closing mechanism (V
It is possible to prevent the liquid refrigerant from accumulating in the second heat source unit (2B) without providing 2).

In the invention according to claim 4, first, when the utilization units (3, 3, ...) Are cooled, the heat source units (2A, 2B) are brought into a cooling cycle state, and the heat source units (2A, 2B) are brought into the cooling cycle state. 2B) high pressure gas refrigerant discharged from the compressor (21),
It condenses in the heat source side heat exchanger (24) to become a liquid refrigerant, and this liquid refrigerant joins in the main liquid line (4L). After that, the liquid refrigerant is divided into each usage unit (3, 3, ...), and in each usage unit (3, 3, ...), the liquid refrigerant is decompressed by the usage side expansion mechanism (33). After that, it is evaporated in the use side heat exchanger (32) to become a low pressure gas refrigerant, and this gas refrigerant passes through the main low pressure gas line (4W) and is split into the low pressure passages (57b, 58b). And, the gas refrigerant, each gas line (5GA, 5GB)
Then, it returns to the compressor (21) of each heat source unit (2A, 2B), and repeats this circulation operation. On the other hand, each usage unit
When heating (3,3, ...), the heat source unit (2A, 2B)
Becomes the heating cycle state, and the high pressure gas refrigerant discharged from the compressor (21) of each heat source unit (2A, 2B) is
GA, 5GB), after joining the main high-pressure gas line (4H) from each high-pressure passage (57a, 58a), each usage unit (3, 3, ...
). Then, in each usage unit (3, 3, ...), the gas refrigerant is condensed in the usage-side heat exchanger (32) to become a liquid refrigerant. The liquid refrigerant passes through the main liquid line (4L) and is split into the liquid passages (53, 54) on the heat source unit (2A, 2B) side. Thereafter, this liquid refrigerant is decompressed by the heat source side expansion mechanism (25), then evaporated in the heat source side heat exchanger (24) to become a low pressure gas refrigerant, and the compressor of each utilization unit (3, 3, ...). Returning to (21), this circulation operation is repeated. When, for example, one usage unit (3) performs heating operation during the cooling operation, simultaneous heating and cooling operation is performed, and during this simultaneous cooling and heating operation, one heat source unit (2A) enters the cooling cycle state. , The other heat source unit (2B) is in the heating cycle state. Then, the compressor (2A) of the heat source unit (2A) of 1
The high pressure gas refrigerant discharged from 1) is condensed in the heat source side heat exchanger (24) to become a liquid refrigerant, and part of the liquid refrigerant or all the liquid refrigerant flows to the other heat source unit (2B) side. After being decompressed,
It is evaporated in the heat source side heat exchanger (24), flows into the compressor (21) and is compressed. After that, the high-pressure gas refrigerant discharged from the compressor (21) flows through the gas line (5 GB), passes through the main high-pressure gas line (4H) as in the heating operation described above, and the heating operation unit (3 , 3,…). Subsequently, the liquid refrigerant condensed in the heating operation use units (3, 3, ...) Passes through the main liquid line (4L) and flows to the indoor unit in the cooling operation as in the cooling operation described above. Then, this liquid refrigerant evaporates in the cooling operation utilization unit (3, 3, ...) to become a low-pressure gas refrigerant, passes through the main low-pressure gas line (4W), and the compressor of the heat source unit (2A) in the cooling cycle state. (2
Returning to 1), this circulation operation is repeated to perform simultaneous cooling and heating operation.

Further, when the heat source units (2A, 2B) are operated in the same cycle, the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B) is connected to the connecting gas line. (10), and each heat source unit (2A,
Refrigerant flowing through the heat source side heat exchanger (24) of 2B) becomes almost even, and COP (coefficient of performance) is improved. Also,
In the invention according to claim 6, each heat source unit (2A, 2B)
In the heat source side heat exchanger (24), the gas side refrigerant pipe (26) communicates not only with the connecting gas line (10) but also through the branch connecting gas passage (10c), and each heat source unit (2A, 2B). The high-pressure refrigerant pressure and the low-pressure refrigerant pressure on the discharge side and the suction side of the compressor (21) become equal, and the high-pressure pressure sensor or the low-pressure pressure sensor or both sensors in each heat source unit (2A, 2B) can be shared.

According to the invention of claim 5, in addition to the operation of the invention of claim 4, for example, when the cooling capacity is required at the time of simultaneous heating and cooling operation, the compression of one heat source unit (2A) is performed. Part of the high-pressure gas refrigerant discharged from the machine (21) flows into the auxiliary gas line (8a), passes through the main high-pressure gas line (4H), and is used as a heating operation unit (3, 3, ...).
The high-pressure gas refrigerant condenses into a liquid refrigerant. This liquid refrigerant is used for both heat source units in the main liquid line (4L).
It joins with the liquid refrigerant from (2A, 2B) and flows into the utilization units (3, 3, ...) In the cooling operation. Further, when the heating capacity is high in the simultaneous heating and cooling operation, a part of the liquid refrigerant is supplied from the main liquid line (4L) to the usage unit (3) for the cooling operation, and the usage unit (3) is used. Evaporates to become a low-pressure gas refrigerant. The low-pressure gas refrigerant passes through the main low-pressure gas line (4W), the auxiliary gas line (8a), and joins with the low-pressure gas refrigerant of one heat source unit (2A).

According to the invention of claim 7, in addition to the operation of the invention of claim 4, the main low-pressure gas line
When equalizing (4W) to the main high-pressure gas line (4H), the above heat source unit (2A) is brought into a heating cycle state. Further, the operation of the other heat source unit (2B) is stopped and the pressure equalizing passage (8c) is communicated. In this state, the high pressure gas refrigerant discharged from the compressor (21) of the heat source unit (2A) is
From the gas line (5LA) to the main high-pressure gas line (4H), and from the pressure equalizing passage (8c) to the main low-pressure gas line (4W).
And the main low pressure gas line (4W) is equalized to a high pressure state. On the contrary, when the main high-pressure gas line (4H) is pressure-equalized to the main low-pressure gas line (4W), the operation of both heat source units (2A, 2B) is stopped and the pressure equalizing passage (8c) is communicated. . In this state, the main high pressure gas line
The high pressure gas refrigerant (4H) flows into the main low pressure gas line (4W), and the main high pressure gas line (4H) is pressure-equalized to a low pressure state.

[0018]

Therefore, according to the invention of claim 1,
The gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in the first heat source unit (2A) and the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in the other heat source unit (2B) The COP (coefficient of performance) can be improved because the refrigerants flowing through the heat source side heat exchangers (24) can be made almost even because they are communicated with each other. In addition, each heat source unit (2A, 2
Since the high pressure sensor during the cooling operation in B) can be shared, the number of parts can be reduced.
Also, at least one heat source unit (2B) liquid line (5L
Since the liquid open / close mechanism (V1) is provided in (B) so that the liquid open / close mechanism (V1) is fully closed when the cooling operation is stopped, liquid refrigerant accumulates in the stopped heat source unit (2B). The other heat source unit (2A) and the usage unit
It is possible to prevent the shortage of the refrigerant amount between (3A, 3B). As a result, a plurality of heat source units (2A, 2B) can be combined. In addition, heat source units (2
Since a plurality of heat source units (2A, 2B) can be combined with each other by producing (A, 2B), a small number of heat source units (2A, 2B) can cope with various types of loads.

Further, according to the invention of claim 2, the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B) is made to communicate with each other. Since the refrigerants flowing through the heat source side heat exchangers (24) can be made almost even, the COP (coefficient of performance) can be improved and at the time of cooling operation in each of the parent heat source units (2A, 2B). Since the high pressure sensor of 1 and the low pressure sensor of heating operation can be shared, the number of parts can be reduced. Furthermore, when the heating operation of the second unit (2B) is stopped, the refrigerant in the stopped second heat source unit (2B) can be reliably recovered in the first heat source unit (2A).
In addition, the gas line (5GB) of the second heat source unit (2B) is provided with a gas opening / closing mechanism (V2), and the liquid line (5LB) is provided with a liquid opening / closing mechanism (V1). Also, the liquid opening / closing mechanism (V1) is closed when the heating operation is stopped, and the gas opening / closing mechanism (V2) is closed when the heating operation of the second heat source unit (2B) is stopped. Heat source unit (2B)
It is possible to prevent the liquid refrigerant from accumulating in, and for example, to prevent the liquid refrigerant from accumulating in the receiver or the like. That is, the liquid refrigerant pressure during operation is higher than the saturation pressure equivalent to the outside air temperature, and the liquid refrigerant may accumulate in the receiver or the like, but this accumulation can be prevented. Further, it is possible to prevent the shortage of the refrigerant amount between the first heat source unit (2A) and the utilization unit (3A, 3B), and to prevent the liquid compression when the child heat source unit (2B) is restarted. Can be prevented. As a result, a plurality of heat source units (2A, 2B) can be combined. Also, since it is possible to create heat source units (2A, 2B) with different capacities and combine these multiple heat source units (2A, 2B), it is possible to use multiple types of heat source units (2A, 2B) Can correspond to.

According to the invention of claim 3, a constant pressure circuit is provided.
The second outdoor unit (2B) is equipped with (9).
Since the high-pressure gas refrigerant does not flow into the second outdoor unit (2B) when is stopped, it is possible to prevent the liquid refrigerant from accumulating. Furthermore, since the gas opening / closing mechanism (V2) in the invention of claim 2 can be omitted, the configuration can be simplified.

According to the invention of claim 4, as in the invention of claim 2, the gas of each heat source side heat exchanger (24) when each heat source unit (2A, 2B) is in the same cycle operation. The refrigerant flowing through the heat source side heat exchanger (24) of each heat source unit (2A, 2B) can be made almost even because the side refrigerant pipe (26) is communicated, so that COP (performance Coefficient) can be improved. In addition, multiple heat source units (2
Since it is not necessary to make a dedicated heat source unit compatible with the simultaneous heating and cooling system, it is possible to support various uses with each heat source unit (2A, 2B). . In particular, each heat source unit (2A, 2B)
Since the liquid line (5LA, 5LB) and the gas line (5GA, 5GB) are only extended, it can be used as a so-called normal heat source unit that does not perform simultaneous cooling and heating operation, so a small number of models Therefore, various operations can be performed, and the heat source unit (2A, 2B) having high versatility can be obtained. Also, heat source units with different capacities (2A, 2B)
Since it is possible to combine the heat source units (2A, 2B) with each other,
Can handle a plurality of indoor units (3, 3, ...), that is, can handle a wide variety of loads.

According to the invention of claim 5, since the auxiliary gas line (8a) is provided, when the demands for the cooling capacity and the heating capacity are balanced, and when the demand for the cooling capacity is large. In addition, even when the heating capacity is required to be large or the cooling and heating capacity is required to be small, the simultaneous cooling and heating operation can be performed. As a result, since the operating range can be expanded, it is possible to deal with various usage conditions. Further, by providing the auxiliary gas line (8a), only the compressor (21) of the one heat source unit (2A) is controlled linearly in accordance with the load by inverter control,
Since the compressor (21) of the other heat source unit (2B) is subjected to three-step unloading control and the operating range can be expanded as described above, it is possible to deal with various aspects with simple control.

Further, according to the invention of claim 6, the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B) is connected to the gas line (10) and the branch connection. Since the gas passage (10c) communicates with each other, it is possible to equalize the high pressure refrigerant pressure and the low pressure refrigerant pressure on the discharge side and the suction side of the compressor (21) in each heat source unit (2A, 2B). The high-pressure pressure sensor or the low-pressure pressure sensor in each heat source unit (2A, 2B) can be shared, or both sensors can be shared. As a result, by providing the high-pressure pressure sensor and the low-pressure pressure sensor only in the one heat source unit (2A), the sensors of the other heat source unit (2B) can be omitted, so that the control accuracy is not deteriorated. The number of parts can be reduced.

Further, according to the invention of claim 7, since the pressure equalizing passage (8c) is provided, the main high pressure gas line is switched at the time of switching the cooling / heating operation in the utilization unit (3).
Since (4H) and the main low-pressure gas line (4W) can be pressure-equalized, it is possible to reliably prevent generation of vibration and noise due to switching. Further, according to the invention of claim 8, the receiver of each heat source unit (2A, 2B) can be omitted by providing one receiver (12), so that the number of parts can be reduced. Furthermore, since the liquid refrigerant can be reliably split, the main liquid line
Even if the flush gas flows in (4 L) or the like, it is possible to reliably prevent the uneven flow.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings. Example 1 FIG. 1 shows an example of the invention according to claim 2,
(1) is an air conditioner as a refrigeration system, which includes two outdoor units (2A, 2B) and two indoor units (3A, 3B)
Are connected in parallel to the main liquid line (4L) and the main gas line (4G), respectively. The outdoor unit (2A, 2B), a compressor (21), a four-way switching valve (22),
An outdoor heat exchanger (24), which is a heat source side heat exchanger in which an outdoor fan (23) is arranged in close proximity, and an outdoor electric expansion valve (25), which is a heat source side expansion mechanism, constitute a heat source unit. . A refrigerant pipe (26) is provided at one end of the outdoor heat exchanger (24) on the gas side.
However, liquid lines (5LA, 5LB) are connected to the other end on the liquid side, respectively. The gas side refrigerant pipe (26) is switchably connected to the discharge side and the suction side of the compressor (21) by the four-way switching valve (22), and the liquid line (5LA, 5LB) is an outdoor unit. The outdoor electric expansion valve (25) and the receiver (27) for storing the liquid refrigerant are sequentially provided from the heat exchanger (24) and connected to the main liquid line (4L). Furthermore, a gas line (5GA, 5GB) is connected to the compressor (21) through a refrigerant pipe (26), and the gas line (5GA, 5GB) is compressed by a four-way switching valve (22). Machine
It is switchably connected to the suction side and the discharge side of (21) and is connected to the main gas line (4G). And
An accumulator (28) is provided in the refrigerant pipe (26) between the suction side of the compressor (21) and the four-way switching valve (22). In addition, the indoor unit (3A, 3B), the indoor heat exchanger (32) is a utilization side heat exchanger in which the indoor fan (31) is arranged in proximity.
And an indoor electric expansion valve (33) which is a use side expansion mechanism to form a usage unit, and the indoor heat exchanger (32) is provided with an indoor liquid pipe (34) and an indoor gas pipe (35). Is connected to the main liquid line (4L) and the main gas line (4G), and the indoor electric expansion valve (33) is provided in the indoor liquid pipe (34).
On the other hand, each of the two outdoor units (2A, 2B) is a unit in which a first outdoor unit (2A) which is a parent outdoor unit and a second outdoor unit (2B) which is a child outdoor unit are connected in parallel. The capacity of each outdoor unit (2A, 2B) is set according to the indoor load, that is, the number of connected indoor units (3A, 3B), and the compressor (21A) of the first outdoor unit (2A) is set. )
Is configured for inverter control, the second outdoor unit (2B)
The compressor (21) of (1) is configured with unload control capable of switching between 100% capacity, 50% capacity and 0% capacity.

Further, the first outdoor unit (2A) and each indoor unit (3A, 3B) are provided with various sensors. In the first outdoor unit (2A), a discharge gas temperature sensor (Th1) for detecting the discharge gas refrigerant temperature of the compressor (21) is installed in the compressor.
A suction gas temperature sensor (Th2) for detecting the suction gas refrigerant temperature of the compressor (21) is provided in the discharge side refrigerant pipe (26) of the compressor (21).
An outdoor liquid temperature sensor (Th3) for detecting the temperature of the liquid refrigerant on the outdoor heat exchanger (24) side is installed in the liquid line (5LA) on the suction side refrigerant pipe (26).
In addition, an outside air temperature sensor (Th4) for detecting the outdoor air temperature is provided near the outdoor heat exchanger (24), and a high pressure sensor (HPS) for detecting the suction refrigerant pressure of the compressor (21).
Is connected to the discharge side refrigerant pipe (26) of the compressor (21) by a low pressure sensor (LPS) that detects the suction refrigerant pressure of the compressor (21).
They are provided in the suction side refrigerant pipes (26) of 1), respectively. In addition, each indoor unit (3A, 3B) has an indoor heat exchanger (3
The indoor liquid temperature sensor (Th5) that detects the liquid refrigerant temperature on the 2) side is installed in the indoor liquid pipe (34), and the indoor gas temperature sensor (Th6) that detects the gas refrigerant temperature on the indoor heat exchanger (32) side is installed indoors. Gas pipe (35)
A room temperature sensor (Th7) for detecting the indoor air temperature is provided near the indoor fan (31). Then, the detection signals of each of the above sensors (Th1 to Th7, HPS, LPS) are input to the controller (6), and the controller (6) causes each sensor (Th1
~ Th7, HPS, LPS) each electric expansion valve (25,
The opening degree of 33) and the capacity of the compressor (21) are controlled.

On the other hand, the air conditioner (1) is provided with a piping unit (11), and the piping unit (11) is connected to the liquid lines (5LA, 5LB) on the outdoor units (2A, 2B) side. ) And the gas line (5GA, 5GB) are connected to the main liquid line (4L) and the main gas line (4G). Specifically, the liquid line (5LA, 5LB) is a liquid pipe (51, 52) extending outward from each outdoor unit (2A, 2B), and a liquid continuous to the outer end of the liquid pipe (51, 52). It is composed of passages (53, 54), and the liquid pipes (51, 52) are
The inner end is connected to the outdoor heat exchanger (24), and the outdoor electric expansion valve (25) and the receiver (27) are provided. The gas lines (5GA, 5GB) above are the outdoor units (2A, 2GB
Gas pipes (55, 56) extending outward from B), and the gas pipes (55, 5)
The gas pipes (55, 56) are connected to the compressor (21) via a four-way switching valve (22). Has been done. Above main liquid line (4
L) is the main liquid pipe extending to the indoor unit (3A, 3B) side
(41) and a main liquid passage (42) continuous to one end of the main liquid pipe (41) and the liquid passages (53, 54) on the outdoor units (2A, 2B) side are continuous. The indoor liquid pipe (34) of the indoor unit (3A, 3B) is connected to the other end of the main liquid pipe (41). The main gas line (4G) is a main gas pipe (43) extending to the indoor unit (3A, 3B) side, and continuous to one end of the main gas pipe (43) and each outdoor unit (2A,
2B) side gas passages (57, 58) are connected to the main gas passage (4
4), and the indoor gas pipe (35) of the indoor unit (3A, 3B) is connected to the other end of the main gas pipe (43).
And, the piping unit (11) is the outdoor unit (2A,
2B) side liquid lines (5LA, 5LB) liquid passages (53, 54) and gas lines (5GA, 5GB) gas passages (57, 58), and main liquid line (4L) main liquid passage (42) And main gas line
The (4G) main gas passage (44) is integrally formed into a unit.

Further, the piping unit (11) is integrally formed with a liquid stop valve (V1) and a gas stop valve (V2). The gas stop valve (V2) is a gas passage (58) in the gas line (5GB) on the second outdoor unit (2B) side.
A gas opening / closing mechanism for opening / closing the gas passage (58), and the gas stop valve (V2) is connected to the gas passage (58) on the second outdoor unit (2B) side and the main gas line. (4G)
Is located close to the connection with the main gas passage (44) of
Based on the control signal of the controller (6), it is configured to be fully closed when the second outdoor unit (2B) is stopped during the heating operation. Also, the liquid stop valve (V1) is
The liquid passage (54) in the liquid line (5LB) on the second outdoor unit (2B) side constitutes a liquid opening / closing mechanism for opening and closing the liquid passage (54), and the liquid stop valve (V1) is It is placed close to the connection between the liquid passage (54) on the second outdoor unit (2B) side and the main liquid passage (42) of the main liquid line (4L), based on the control signal from the controller (6). It is configured to be fully closed when the second outdoor unit (2B) is stopped during the cooling and heating operations.

The second outdoor unit (2B) includes a compressor (2
A bypass line (29) that is connected to the discharge side and the suction side of the compressor (21) by bypassing 1) is provided, and the bypass line (29) opens and closes the bypass line (29). A bidirectional bypass stop valve (V3) is installed. Then, the controller (6) has a second outdoor unit (2B).
The bypass stop valve (V3), the outdoor electric expansion valve (25), the liquid stop valve (V1) and the gas stop valve (V
2) and the liquid refrigerant in the second outdoor unit (2B) is opened for a predetermined time, for example, 1 to 2 minutes, and the first outdoor unit (2A)
Refrigerant discharging means (61) for discharging to the side is provided. Further, the controller (6) is provided with a refrigerant amount detection means (62) and a refrigerant recovery means (63). The refrigerant amount detecting means
(62) is an outdoor electric expansion valve (2) of the first outdoor unit (2A) during heating operation and when the second outdoor unit (2B) is stopped.
When 5) is fully open and the refrigerant superheat degree of the outdoor heat exchanger (24) based on the detection signals of the outdoor liquid temperature sensor (Th3) and the suction gas temperature sensor (Th2) exceeds the specified temperature, the insufficient amount of refrigerant is detected. Is configured to. The refrigerant recovery means (63),
When the refrigerant amount detecting means (62) detects the refrigerant amount shortage, the liquid stop valve (V1) is opened for a predetermined time when the second outdoor unit (2B) is stopped during the heating operation, and the indoor electric expansion valve (33) is also provided. Is squeezed for a predetermined time to reduce the liquid refrigerant to a saturation pressure corresponding to the outside air temperature, and the liquid refrigerant in the stopped second outdoor unit (2B) is evaporated and recovered. The refrigerant recovery means (63) also opens the outdoor electric expansion valve (25) for a predetermined time when the outdoor electric expansion valve (25) in the stopped second outdoor unit (2B) is not opened. Is configured to let.

Further, as a feature of the present invention, a connecting gas line (10) is provided between the first outdoor unit (2A) and the second outdoor unit (2B). The connected gas line (1
0) has one end connected to the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the first outdoor unit (2A), and the other end in the outdoor heat exchanger (24 in the second outdoor unit (2B). ) Is connected to the gas side refrigerant pipe (26). Further, in the connecting gas line (10), a connecting gas passage (10b) is continuously formed at an outer end of a connecting gas pipe (10a) extending outward from each outdoor unit (2A, 2B). (10b) is a connection stop valve (V4) which is a connection opening / closing mechanism that is fully closed when the cooling operation of the second outdoor unit (2B) is stopped and blocks the refrigerant flow to the second outdoor unit (2B). Is provided. The connection gas passage (10b) and the connection stop valve (V4) are integrated into the piping unit (11) to form a unit.

-Operational Behavior of First Embodiment- Next, the control operation of the air conditioner (1) will be described. First, during cooling operation, the four-way selector valve (2
2) is changed to the broken line in Fig. 1, and the high pressure gas refrigerant discharged from the compressors (21) of both outdoor units (2A, 2B) is transferred to the outdoor heat exchanger (2).
It condenses in 4) and becomes a liquid refrigerant, and this liquid refrigerant joins in the main liquid passage (42) of the piping unit (11). After that, the liquid refrigerant is decompressed by the indoor electric expansion valve (33) and then evaporated in the indoor heat exchanger (32) to become a low pressure gas refrigerant, and this gas refrigerant is passed through each gas passage in the piping unit (11). Divide into (57, 58),
The circulation operation is repeated by returning to the compressor (21) of each outdoor unit (2A, 2B). On the other hand, during heating operation, the four-way switching valve (22) is switched to the solid line in FIG. 11), after joining in the main gas passage (44) of the piping unit (11), the indoor unit (3A, 3A
B). And, this gas refrigerant, the indoor heat exchanger (3
It condenses in 2) and becomes a liquid refrigerant, and this liquid refrigerant flows from the main liquid passage (42) of the piping unit (11) to each outdoor unit (2A, 2B).
It is diverted to the liquid passage (53, 54) on the side. Then, this liquid refrigerant is decompressed by the outdoor electric expansion valve (25), and then the outdoor heat exchanger.
(24) evaporates to become low-pressure gas refrigerant, and each outdoor unit (2
It returns to the compressor (21) of A, 2B) and repeats this circulation operation. During the above cooling operation and heating operation, the controller (6) controls the opening degree of each indoor electric expansion valve (33) and each outdoor electric expansion valve (25), and each outdoor unit (corresponding to the indoor load). It controls the capacity of the compressor (21) in 2A, 2B). Specifically, the controller (6) controls the compressor (21) of the second outdoor unit (2B) to have 100% capacity and 50% capacity, and also controls the compressor (2) of the first outdoor unit (2A).
The capacity of 1) is controlled almost linearly according to the load by inverter control. And the indoor unit (3A, 3B)
When the load on the second outdoor unit (2A) is reduced and the capacity of the first outdoor unit (2A) can be dealt with, the operation of the second outdoor unit (2B) is stopped.

Further, the controller (6) closes the liquid stop valve (V1) at the time of stopping the cooling operation and the heating operation of the second outdoor unit (2B) to prevent the accumulation of the liquid refrigerant in the receiver (27) and the like. To prevent. In other words, the liquid refrigerant pressure during operation is
Since it is higher than the saturation pressure equivalent to the outside air temperature, the liquid refrigerant may be accumulated in the receiver (27), so that the accumulation is prevented. Further, the controller (6) is a gas stop valve when the heating operation of the second outdoor unit (2B) is stopped.
(V2) is closed to prevent the liquid refrigerant from accumulating in the stopped second outdoor unit (2B), and the first outdoor unit
The shortage of the amount of refrigerant between (2A) and the outdoor unit (2A, 2B) is prevented. Further, immediately after the heating operation of the second outdoor unit (2B) is stopped, the refrigerant discharge means (61) causes the bypass stop valve (V3) and the outdoor electric expansion valve (2) of the second outdoor unit (2B).
5) The liquid stop valve (V1) and the gas stop valve (V2) are opened for a predetermined time, for example, for 1 to 2 minutes. As a result, the high pressure gas refrigerant flows from the first outdoor unit (2A) to the liquid line (5LB) via the gas line (5GB) of the second outdoor unit (2B), and the second outdoor unit (2
The liquid refrigerant in B) is discharged to the main liquid line (4L) and the like to prevent a shortage of the refrigerant amount. In other words, when the refrigerant flows through the main gas line (4G), etc., the refrigerant pressure will decrease due to pressure loss, but during heating operation, in the indoor unit (3A, 3B), the pressure loss in the pipe length etc. The difference is corrected by the indoor electric expansion valve (33). As a result, since the refrigerant pressure in the main liquid line (4L) becomes lower than the discharge pressure of the compressor (21), the liquid refrigerant in the second outdoor unit (2B) is discharged to the main liquid line (4L) and the like. Will be done.

Further, during the heating operation stop of the second outdoor unit (2B), the refrigerant amount detecting means (62) detects whether or not the amount of refrigerant is insufficient, that is, the first outdoor unit (2A).
Outdoor electric expansion valve (25) is fully open and outdoor temperature sensor
When the refrigerant superheat degree of the outdoor heat exchanger (24) based on the detection signals of (Th3) and the suction gas temperature sensor (Th2) becomes equal to or higher than a predetermined temperature, the insufficient amount of refrigerant is detected. And the refrigerant amount detecting means
When (62) detects a refrigerant shortage, the refrigerant recovery means (63),
The liquid stop valve (V1) is opened for a predetermined time, and the indoor electric expansion valve (33) is throttled for a predetermined time to reduce the liquid refrigerant to a saturation pressure equivalent to the outside air temperature, and the second outdoor unit (2B) is stopped.
The liquid refrigerant is evaporated to collect the refrigerant in the first outdoor unit (2A). At this time, the refrigerant recovery means (63) also includes the outdoor electric expansion valve (25) when the outdoor electric expansion valve (25) in the stopped second outdoor unit (2B) is not open. It will be opened for a predetermined time.

Further, as a feature of the present invention, both the outdoor unit (2) is used during both the cooling operation and the heating operation.
(A, 2B) is operating, the connection stop valve (V4) is opened, high-pressure gas refrigerant flows through both outdoor heat exchangers (24) almost uniformly during cooling operation, and during heating operation. The low-pressure gas refrigerant flows through the outdoor heat exchangers (24) almost uniformly. For example, during the cooling operation, the second outdoor unit (2
When the operating capacity of B) increases with the load, the compressor (21)
A part of the refrigerant discharged from the refrigerant flows through the connecting gas line (10) to the outdoor heat exchanger (24) in the first outdoor unit (2A). Further, during the heating operation, when the operating capacity of the second outdoor unit (2B) becomes large with respect to the load, part of the refrigerant from the outdoor heat exchanger (24) in the first outdoor unit (2A) becomes a connected gas line ( 10) Pass through 2nd outdoor unit
It will be sucked into the compressor (21) of (2B). Further, when the cooling operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) is fully closed, and as described above, the gas stop valve (V2) is in the open state, and the second outdoor unit (2B) is opened. The refrigerant) is sucked into the low pressure side of the first outdoor unit (2A). Further, when the heating operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) maintains the open state, and the gas stop valve (V2) is fully closed as described above. Refrigerant for outdoor unit (2B) is connected gas line (10)
Will be sucked to the low pressure side of the first outdoor unit (2A).

-Effect of Embodiment 1- Therefore, according to this embodiment, the first outdoor unit (2A) is used.
And the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the
The refrigerant flowing through each outdoor heat exchanger (24) should be made almost even, as it should be in communication with the gas side refrigerant piping (26) of the outdoor heat exchanger (24) in the outdoor unit (2B). Therefore, the COP (coefficient of performance) can be improved. Furthermore, since the high pressure sensor during the cooling operation and the low pressure sensor during the heating operation can be shared in each outdoor unit (2A, 2B), the number of parts can be reduced. Furthermore, when the heating operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) remains open,
The refrigerant in the stopped second outdoor unit (2B) can be reliably collected in the first outdoor unit (2A).

Since a gas stop valve (V2) is provided in the gas line (5GB) on the side of the second outdoor unit (2B), the second
When the heating operation of the outdoor unit (2B) is stopped, the gas stop valve (V
2) can be closed to prevent the liquid refrigerant from accumulating in the stopped second outdoor unit (2B).
It is possible to prevent a shortage of the refrigerant amount between the (2A) and the indoor units (3A, 3B). The second outdoor unit (2B)
Since the liquid stop valve (V1) was installed in the liquid line (5LB) on the side,
When the cooling operation and the heating operation in the second outdoor unit (2B) are stopped, the liquid stop valve (V1) is closed and the receiver (2
It is possible to prevent the liquid refrigerant from accumulating in 7) and the like. As a result, a plurality of outdoor units (2A, 2B) can be combined. In addition, outdoor units with different capacities (2
A, 2B) can be manufactured and two outdoor units (2A, 2B) can be combined, so a small number of outdoor units
(2A, 2B) can support multiple indoor units (3A, 3B).

Further, since the refrigerant discharge means (61) is provided, the high pressure gas refrigerant is supplied to the liquid line (5LB) on the second outdoor unit (2B) side immediately after the heating operation of the second outdoor unit (2B) is stopped. ) To the second outdoor unit (2
Since the liquid refrigerant in B) can be discharged to the main liquid line (4L) or the like, it is possible to reliably prevent the shortage of the refrigerant amount. Further, if the refrigerant amount detection means (62) and the refrigerant recovery means (63) are provided, and if a shortage of the refrigerant amount is detected, the indoor electric expansion valve (33) is throttled to bring the liquid refrigerant to a saturation pressure equivalent to the outside air temperature. Since the liquid refrigerant in the stopped second outdoor unit (2B) is evaporated to collect the refrigerant in the first outdoor unit (2A), it is possible to reliably prevent the shortage of the refrigerant amount. In addition, the piping connection between each outdoor unit (2A, 2B) and each indoor unit (3A, 3B) is configured in the piping unit (11), so the piping inclination angle required for oil return etc. can be ensured. In addition to being able to maintain the above, it is possible to reliably keep the position requiring horizontal piping in the horizontal state. As a result, the oil can be reliably returned and the liquid refrigerant can be prevented from being flushed, so that highly reliable air conditioning operation can be performed. Furthermore, since it is possible to reduce the number of pipes when installing the two outdoor units (2A, 2B), it is possible to reduce the man-hours of the plumbing work and to simplify the work.

Embodiment 2 As shown in FIG. 2, in this embodiment, one receiver (12) is provided in the piping unit (11). The receiver
(12) is located at the connection between the liquid passages (53, 54) on the side of each outdoor unit (2A, 2B) and the main liquid passage (42), and stores the liquid refrigerant, while at the same time, each outdoor unit during cooling operation. Liquid refrigerant from (2A, 2B) will be joined to the main liquid line (4L), and liquid refrigerant from the main liquid line (4L) will be distributed to each outdoor unit (2A, 2B) during heating operation. . At that time, in each outdoor unit (2A, 2B), the receiver (27) in FIG. 1 is omitted, and instead of closing the liquid stop valve (V1),
Since the outdoor electric expansion valve (25) is fully closed, the liquid stop valve
(V1) is omitted. And the second outdoor unit
When the operation of (2B) is stopped, the outdoor electric expansion valve (25) of the second outdoor unit (2B) is controlled to be fully closed to form a liquid opening / closing mechanism. Further, the second outdoor unit (2B) is provided with an auxiliary bypass line (29a) in parallel with the bypass line (29). The auxiliary bypass line (29a) is provided with a check valve (V5) that allows the refrigerant to flow from the suction side to the discharge side of the compressor (21). That is, if the bypass stop valve (V3) of the bypass line (29) is a one-way valve that allows the refrigerant to flow from the discharge side to the suction side of the compressor (21), the second outdoor unit (2B) When the heating operation of the unit is stopped, the refrigerant in the second outdoor unit (2B) is connected to the connected gas line.
It will be sucked to the low pressure side of the first outdoor unit (2A) through (10), but at this time, the four-way switching valve (22) will stop in the cooling cycle as shown by the solid line in FIG. Sometimes. In this case, since the refrigerant needs to flow through the compressor (21), the auxiliary bypass line (29a) is provided so that the refrigerant can be reliably sucked. Therefore, according to the present embodiment, since the receiver of each outdoor unit (2A, 2B) can be omitted by providing one receiver (12), the number of parts can be reduced. Furthermore,
Since the liquid refrigerant can be reliably divided, even if the flush gas flows through the main liquid line (4L) or the like, uneven flow can be reliably prevented. Other than that, the configuration, operation, and effects of the connecting gas line (10) and the like are similar to those of the first embodiment shown in FIG.

Embodiment 3 FIG. 3 is a valve circuit showing a modification of the gas stop valve (V2).
(13) The first flow path (13) having a check valve (V6) capable of flowing from the second outdoor unit (2B) to the main gas line (4G)
a) and a second flow path (13b) having a stop valve (V7) that opens during cooling operation. Other than that, the configuration, operation and effects of the connecting gas line (10) and the like are similar to those of the second embodiment of FIG. The bypass stop valve (V3) is bidirectional and the auxiliary bypass line (29a) is omitted.

-Modification of Third Embodiment- FIG. 4 shows an external pressure equalizing type reversible valve (1a) showing another modification of the gas stop valve (V2). Is connected to the pilot circuit (14). The pilot circuit (14) is provided with a check valve (V8, V9) and is connected to the main gas line (4G) and the main liquid line (4L), and a high pressure circuit (14a) for guiding high pressure refrigerant, and a check valve. The low pressure circuit (14b) is provided with valves (V10, V11) and is connected to the main gas line (4G) and the main liquid line (4L) to maintain a low pressure state. The external pressure equalizing type reversible valve (1a) is composed of a valve body and a pilot valve (not shown), and the valve body is
The gas passage (58) on the second outdoor unit (2B) side is connected, and the gas passage (58) is switched between a communication state and a closed state. On the other hand, the pilot valve is connected to the high pressure circuit (1
4a) and the low pressure circuit (14b) are connected, high pressure or low pressure is led to the valve body by the control signal of the controller (6), and the gas passage (58) is connected or cut off. In addition, the configuration and operation of the connected gas line (10), etc.
The effect is similar to that of the previous embodiment shown in FIG.

-Embodiment 4- FIG. 5 shows another embodiment, which is an embodiment of the invention according to claim 3 and is the same as the gas stop valve (V2) in the second embodiment shown in FIG. Instead, branch line (5a) and constant pressure circuit
(9) and are provided. The branch line (5a) is
A branch passage (5c) is continuously formed at an outer end of a branch pipe (5b) extending outside the first outdoor unit (2A), and an inner end of the branch pipe (5b) has the first outdoor unit (2A). ) Is connected to the refrigerant pipe (26) between the outdoor heat exchanger (24) and the four-way switching valve (22). The outer end of the branch passage (5c) is a constant pressure circuit.
It is connected to (9). On the other hand, the constant pressure circuit (9) includes a constant high pressure passage (91) and a constant low pressure passage (92), and one end of the constant high pressure passage (91) and the constant low pressure passage (92) has a check valve. (V12, V13) to the branch passage (5c), the other end is connected to the main gas line via a four-way switching valve (V14).
It is connected to the (4G) main gas passage (44). The non-return valve (V12) of the constant high pressure passage (91) allows the refrigerant to flow from the branch passage (5c) to the constant high pressure passage (91), and the low pressure passage (9)
The check valve (V13) of 2) is a branch passage from the constant low pressure passage (92).
It is configured to allow the refrigerant to flow to (5c). Further, the four-way switching valve (V14) is switched to a broken line during cooling operation, the low-pressure gas refrigerant is constantly switched to the low-pressure passage (92), and the heating operation is switched to a solid line, and the high-pressure gas refrigerant is constantly switched to the high-pressure passage (91). Is configured to lead to. In addition, the constant high pressure passage (9
1) is a check valve (V15, V16) in which the main gas passage (44) and the gas passage (58) on the side of the second outdoor unit (2B) always allow the refrigerant to flow toward the high pressure passage (91). The main gas passage (44) and the gas passage (58) on the second outdoor unit (2B) side are connected to each other via the main gas passage (44). ) And a gas passage (58) through check valves (V17, V18) that allow the refrigerant to flow, and are always kept in a low pressure state. And the constant pressure circuit (9)
And the branch passage (5c) are integrated into the piping unit (11) to form a unit.

-Effects of the fourth embodiment- Therefore, since the constant pressure circuit (9) and the refrigerant recovery passageway (8a) are provided, when the second outdoor unit (2B) is stopped during the heating operation, the second outdoor unit (2B) is stopped. The gas passageway (58) of the outdoor unit (2B) communicates with the low pressure side of the first outdoor unit (2A) via the connecting gas line (10) and the low pressure passageway (92), and the second outdoor unit ( The accumulation of liquid refrigerant in 2B) is prevented. Since the gas stop valve (V2) in FIG. 2 can be omitted, the number of parts can be reduced. In addition, the refrigerant discharge means (61) as in the embodiment shown in FIG.
Since the refrigerant recovery means (63) can be omitted, the configuration can be further simplified. In addition, the configuration, operation, and effects of the connecting gas line (10), etc. are shown in the second part of FIG.
It is similar to the embodiment. The bypass line (29) and the like are not shown.

Embodiment 5 FIGS. 6 and 7 show an embodiment of the invention according to claim 4, which is two outdoor units (2A, 2B) and a plurality of indoor units (3, 3,). ...) are connected in parallel to the main liquid line (4L), the main high pressure gas line (4H) and the main low pressure gas line (4W), respectively. The outdoor unit (2
A, 2B) is constructed similarly to the second embodiment shown in FIG. 2, but with the bypass line (29) and the auxiliary bypass line (29).
a) is not shown. Also, gas line (5GA, 5GB)
Is connected to the suction side and the discharge side of the compressor (21) by a four-way switching valve (22) and is connected to the main high pressure gas line (4H) and the main low pressure gas line (4W). There is. Further, the indoor unit (3, 3, ...) Is configured similarly to the second embodiment shown in FIG. 2, but the indoor gas pipe (35) is an indoor high pressure pipe (36) and an indoor low pressure pipe (36). 37) and are connected to. The indoor high pressure pipe (36) is connected to the main high pressure gas line (4H), and the indoor low pressure pipe (37) is connected to the main low pressure gas line (4W).

Further, a part of the indoor liquid piping (34), a part of the indoor gas piping (35), the indoor high pressure piping (36) and the indoor low pressure piping (37) are a piping kit (7). Are integrally formed by. The piping kit (7) includes a high pressure valve (71) and a low pressure valve (72).
And a low pressure bypass path (73) and a high pressure bypass path (74). The high-pressure valve (71) is an indoor high-pressure pipe (3
6), the low pressure valve (72) is provided in the indoor low pressure pipe (37), the high pressure valve (71) and the low pressure valve (72), the main high pressure gas line (4H) to the indoor heat exchanger (32). ) And the main low pressure gas line
The communication with (4W) is switched, and when the indoor heat exchanger (32) functions as an evaporator (during cooling), the low pressure valve (72) increases the pressure when it functions as a condenser (during heating). Each valve (71) opens. Furthermore, the low-pressure bypass passage (73) is connected to the indoor liquid pipe (34) and the downstream side of the low-pressure valve (72) in the indoor low-pressure pipe (37), the bypass valve (75) and the capillary (76). A pipe heat exchanger (77) is formed between the indoor liquid pipe (34) and the pipe heat exchanger (77). Then, the low-pressure bypass path (7
In 3), the liquid refrigerant flowing out from the indoor heat exchanger (32) is prevented from flushing during the heating operation. The high-pressure bypass passage (74) is connected to the indoor gas pipe (35) and the upstream side of the high-pressure valve (71) in the indoor high-pressure pipe (36), and is provided with a flow rate-adjusting capillary (78). And high-pressure indoor piping (3
6) The condensate collected in etc. is bypassed.

On the other hand, the piping unit (11) is the same as in the first embodiment.
Different from the fourth embodiment, liquid lines (5LA, 5LB) and gas lines (5GA, 5GB), main liquid line (4L), main high pressure gas line (4H) and main low pressure of each outdoor unit (2A, 2B) side It is connected to the gas line (4W). Specifically, the above liquid lines (5LA, 5LB) are the same as in the second embodiment, except that
Liquid pipes (51, 52) extending outward from (2A, 2B) and the liquid pipes (51, 52).
It is composed of a liquid passage (53, 54) continuous to the outer end of (52),
The gas lines (5GA, 5GB) include a gas pipe (55, 56) extending outward from the outdoor unit (2A, 2B) and a gas passage (57, 58) continuous to the outer end of the gas pipe (55, 56). ) And. Furthermore, the gas passages (57, 58) are high pressure passages (57a, 58).
a) and a low pressure passage (57b, 58b), the high pressure passage (57a, 58a) allows the refrigerant flow in the discharge direction from the compressor (21), specifically, each outdoor unit Check valves (V21, V22) that allow the refrigerant to flow from (2A, 2B) to the main high-pressure gas line (4H) are provided. In addition, the low pressure passage (5
7b, 58b) is a check valve that allows the refrigerant to flow in the suction direction of the compressor (21) and specifically allows the refrigerant to flow from the main low-pressure gas line (4W) to the outdoor unit (2A, 2B). (V23, V2
4) is provided. That is, the outdoor unit (2A, 2B)
The two of the liquid pipes (51, 52) and the gas pipes (55, 56) are extended, and they are not configured as a dedicated outdoor unit of the simultaneous heating and cooling system.

The main liquid line (4 L) is an indoor unit
The liquid in the liquid line (5A, 5B) continuous to the main liquid pipe (41a) extending to the (3, 3, ...) side and one end of the main liquid pipe (41a) and on each outdoor unit (2A, 2B) side The main liquid passage (41b) is connected to the passages (51, 52). The main liquid pipe (41a) is provided with a branch liquid pipe (41c, 41c, ...
), Each of the branch liquid pipes (41c) is connected to the indoor unit.
It is connected to the (3,3, ...) Indoor liquid piping (34). The main high-pressure gas line (4H) is connected to the main high-pressure gas pipe (42a) extending toward the indoor unit (3, 3, ...) side, and is continuous to one end of the main high-pressure gas pipe (42a) and is connected to each outdoor unit (2A). , 2B) side gas lines (5GA, 5GB) and main high-pressure gas passages (57a, 58a) are connected to the main high-pressure gas passage (42b). The main high-pressure gas pipe (42a) is branched to a branch high-pressure pipe (42c, 42c, ...) Through a flow divider (45), and each branch high-pressure pipe
(42c) is the indoor high pressure piping (3) of the indoor unit (3,3, ...).
Connected to 6). Above main low pressure gas line (4W)
Is a main low-pressure gas pipe (43a) extending to the indoor unit (3, 3, ...) Side, and a gas line (continuous to one end of the main low-pressure gas pipe (43b) and on each outdoor unit (2A, 2B) side ( (5GA, 5GB)
And a main low-pressure gas passage (43b) connected to the low-pressure passages (57b, 58b). The main low-pressure gas pipe (43a) is divided into low-pressure pipes (43c, 43c, ...
), And each branch low-pressure pipe (43c) is connected to the indoor low-pressure pipe (37) of the indoor unit (3, 3, ...). The piping unit (11) is connected to each outdoor unit (2A, 2
Liquid passage (5LA, 5LB) on the (B) side, gas passages (57, 58) for gas lines (5GA, 5GB), and main liquid line (4
L) main liquid passage (41b) and main high pressure gas line (4H)
Main high pressure gas passage (42b) and main low pressure gas line
(4W) main low-pressure gas passage (43b) and the above check valve (V21 ~
It is integrally formed with V24) into a unit.

On the other hand, as a feature of the present invention, as in the first embodiment of FIG. 1, a connecting gas line (10) is provided between the first outdoor unit (2A) and the second outdoor unit (2B). Is provided. One end of the connecting gas line (10) is a gas side refrigerant pipe (2) of the outdoor heat exchanger (24) in the first outdoor unit (2A).
6) and the other end is connected to the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the second outdoor unit (2B). Further, in the connecting gas line (10), a connecting gas passage (10b) is continuously formed at an outer end of a connecting gas pipe (10a) extending outward from each outdoor unit (2A, 2B). (10b) is a connection stop valve that is a connection opening / closing mechanism that is fully closed when the cooling operation of the second outdoor unit (2B) is stopped to prevent the refrigerant from flowing into the second outdoor unit (2B).
(V4) is provided. Then, the connection gas passage (10
b) and the connection stop valve (V4) are integrated into the piping unit (11) to form a unit.

-Operation of Embodiment 5- Next, the control operation of the air conditioner (1) will be described. First, when cooling each indoor unit (3, 3, ...), the four-way switching valve (22) switches to the solid line in Fig. 6 and discharges from the compressor (21) of both outdoor units (2A, 2B). The high-pressure gas refrigerant is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and the liquid refrigerant joins in the main liquid passage (41b) of the piping unit (11). Thereafter, the liquid refrigerant is divided into the indoor units (3, 3, ...) In the flow divider (45), while the indoor units are separated.
In (3,3, ...), the high pressure valve (71) is closed and the low pressure valve (7
Since 2) is opened, the above liquid refrigerant is used for indoor electric expansion valve (33).
After being decompressed by, the indoor heat exchanger (32) evaporates into a low-pressure gas refrigerant, and this gas refrigerant passes from the indoor low-pressure pipe (37) through the main low-pressure gas line (4W) and in the piping unit (11). Divide into each low pressure passage (67, 68). Then, the gas refrigerant is supplied from each gas line (5GA, 5GB) to each outdoor unit (2A, 2GB).
Returning to the compressor (21) of B), this circulation operation is repeated. Further, when the indoor units (3, 3, ...) Are heated, the four-way switching valve (22) switches to the broken line in FIG. 6, and the compressors (21) of both outdoor units (2A, 2B) are switched. The high-pressure gas refrigerant discharged from the gas line (5GA, 5GB) passes through the piping unit.
At (11), after joining the high pressure passages (57a, 58a) to the main high pressure gas passage (42b), the flow is divided into the indoor units (3, 3, ...) By the flow divider (45). And each indoor unit
In (3,3, ...), the high pressure valve (71) is opened and the low pressure valve (7
2) is closed, so the above gas refrigerant is used for indoor high pressure piping (36).
Through the indoor heat exchanger (32) to be a liquid refrigerant. This liquid refrigerant passes through the main liquid line (4L), and the piping unit
From the main liquid passage (41b) of (11) to each outdoor unit (2A, 2B)
It is diverted to the liquid passage (53, 54) on the side. Then, this liquid refrigerant is decompressed by the outdoor electric expansion valve (25), and then the outdoor heat exchanger.
(24) evaporates to become low-pressure gas refrigerant, and each outdoor unit (2
It returns to the compressor (21) of A, 2B) and repeats this circulation operation.

On the other hand, during the cooling operation, for example, the high pressure valve (71) and the low pressure valve (72) of one indoor unit (3) are switched, and this one indoor unit (3) performs heating operation. When,
On the contrary, during the heating operation, for example, the high pressure valve (71) and the low pressure valve (72) of one indoor unit (3) are switched to each other.
When one indoor unit (3) performs cooling operation, simultaneous cooling and heating operation is performed. During the simultaneous heating and cooling operation, the four-way switching valve (22) of the first outdoor unit (2A) is switched to the solid line in FIG. 6 to bring the first outdoor unit (2A) into the cooling cycle state, and the second outdoor unit Unit (2B) four-way switching valve
(22) is switched to the broken line in FIG. 1 to bring the second outdoor unit (2B) into the heating cycle state. And the first outdoor unit
The high-pressure gas refrigerant discharged from the compressor (21) of (2A) is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and this liquid refrigerant flows into the piping unit (11) and a part of the liquid refrigerant. , Or all of the liquid refrigerant flows to the second outdoor unit (2B) through the liquid passage (54) on the second outdoor unit (2B) side, and after being decompressed by the outdoor electric expansion valve (25), the outdoor It is evaporated in the heat exchanger (24) and flows into the compressor (21) for compression. After that, the high-pressure gas refrigerant discharged from the compressor (21) flows through the gas line (6B) on the second outdoor unit (2B) side, and passes through the piping unit (11) as in the heating operation described above. Flow through the main high pressure gas line (4H) to the indoor units (3,3, ...) In heating operation. Then, the liquid refrigerant condensed in the indoor heat exchanger (32) in the indoor unit (3, 3, ...) In the heating operation is transferred to the main liquid line (4).
It flows into the flow divider (45) through the branch liquid pipe (41c) of L). At that time, when the liquid refrigerant flows from the first outdoor unit (2A) to the main liquid line (4L), the liquid refrigerant from the first outdoor unit (2A) and the indoor unit (3, 3, , And the liquid refrigerant flows through the branch liquid pipe (41c) to the indoor units (3, 3, ...) In the cooling operation as in the cooling operation described above. Then, this liquid refrigerant evaporates in the air-conditioning indoor units (3, 3, ...) to become a low-pressure gas refrigerant, passes through the main low-pressure gas line (4W), and goes through the low-pressure gas line ( 6A) and returns to the compressor (21) of the first outdoor unit (2A), and repeats this circulation operation,
Simultaneous cooling and heating operation will be performed.

In the simultaneous heating and cooling operation described above,
When the first outdoor unit (2A) is in the cooling cycle state,
The outdoor unit (2B) is in the heating cycle state, but the four-way switching valve (22) of the first outdoor unit (2A) is switched to the broken line in FIG. 1 to put the first outdoor unit (2A) in the heating cycle state. The same applies when the four-way switching valve (22) of the second outdoor unit (2B) is switched to the solid line in FIG. 6 and the second outdoor unit (2B) is in the cooling cycle state. At that time, the high-pressure gas refrigerant discharged from the compressor (21) of the second outdoor unit (2B) is the outdoor heat exchanger (24).
Is condensed into liquid refrigerant, and some or all of the liquid refrigerant flows into the first outdoor unit (2A), evaporates and is compressed.
It is compressed at (21) and flows through the main high pressure gas line (4H).

Further, as a feature of the present invention, both the outdoor unit (2
(A, 2B) is operating, the connection stop valve (V4) is opened, high-pressure gas refrigerant flows through both outdoor heat exchangers (24) almost uniformly during cooling operation, and during heating operation. The low-pressure gas refrigerant flows through the outdoor heat exchangers (24) almost uniformly. For example, during the cooling operation, the second outdoor unit (2
When the operating capacity of B) increases with the load, the compressor (21)
A part of the refrigerant discharged from the refrigerant flows through the connecting gas line (10) to the outdoor heat exchanger (24) in the first outdoor unit (2A). Further, during the heating operation, when the operating capacity of the second outdoor unit (2B) becomes large with respect to the load, part of the refrigerant from the outdoor heat exchanger (24) in the first outdoor unit (2A) becomes a connected gas line ( 10) Pass through 2nd outdoor unit
It will be sucked into the compressor (21) of (2B). Further, when the cooling operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) is fully closed, and as described above, the gas stop valve (V2) is in the open state, and the second outdoor unit (2B) is opened. The refrigerant) is sucked into the low pressure side of the first outdoor unit (2A). Further, when the heating operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) maintains the open state, and the gas stop valve (V2) is fully closed as described above. Refrigerant for outdoor unit (2B) is connected gas line (10)
Will be sucked to the low pressure side of the first outdoor unit (2A).

-Effect of Fifth Embodiment-Accordingly, according to the present embodiment, the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the first outdoor unit (2A) is the same as in the first embodiment. ) And the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the second outdoor unit (2B) are connected to each other, and the refrigerant flowing through each outdoor heat exchanger (24) is Since they can be made uniform, COP (coefficient of performance) can be improved. Furthermore, since the high pressure sensor during the cooling operation and the low pressure sensor during the heating operation can be shared in each outdoor unit (2A, 2B), the number of parts can be reduced. Furthermore, the second outdoor unit
When the heating operation of (2B) is stopped, the connection stop valve (V4) is still open, so the refrigerant in the stopped second outdoor unit (2B) is reliably collected in the first outdoor unit (2A). be able to.

Further, since the two outdoor units (2A, 2B) are provided, it is not necessary to provide a dedicated outdoor unit corresponding to the simultaneous heating and cooling operation system, so each outdoor unit (2A, 2B) Therefore, it can be used for various purposes. In particular, since the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are only extended from the outdoor units (2A, 2B), the so-called normal outdoor that does not perform simultaneous heating and cooling operation. Since it can be used as a unit,
Various types of operation can be performed with a small number of models, making it a highly versatile outdoor unit (2A, 2B).
In addition, we made outdoor units (2A, 2B) with different capacities
Since it is possible to combine two outdoor units (2A, 2B), a small number of outdoor units (2A, 2B) can handle multiple indoor units (3, 3, ...), that is, multiple types of loads. be able to. In addition, connect the piping connection between the above liquid lines (5LA, 5LB) and the main liquid line (4L) to the piping unit (11).
With the above configuration, it is possible to reliably maintain the pipe inclination angle required for oil return and the like, and it is also possible to reliably maintain the horizontal position where horizontal piping is required. As a result, it is possible to reliably return the oil, prevent flash of the liquid refrigerant, and perform highly reliable air conditioning operation.

-Embodiment 6- FIG. 8 shows another embodiment, which is an embodiment of the invention according to claims 5 and 6, and is an air conditioner (1) of Embodiment 5 shown in FIG. In the above, the auxiliary gas line (8a) is provided so that the operating capacity can be adjusted. The auxiliary gas line (8
In a), the auxiliary gas passage (82) is continuously formed at the outer end of the auxiliary gas pipe (81) extending outside the first outdoor unit (2A),
The inner end of the auxiliary gas pipe (81) is the first outdoor unit (2A).
Is connected to the refrigerant pipe (26) between the outdoor heat exchanger (24) and the four-way switching valve (22). In addition, the auxiliary gas passage
The (82) is branched into a high pressure auxiliary passage (83) and a low pressure auxiliary passage (84), and the high pressure auxiliary passage (83) is connected to the main high pressure gas passage (42b) and at the same time as the first outdoor unit. A check valve (V25) is provided which allows the refrigerant to flow from the unit (2A) to the main high pressure gas line (4H). On the other hand, the low-pressure auxiliary passage (84) is connected to the main low-pressure gas passage (43b) and is connected to the first outdoor unit (2W) from the main low-pressure gas line (4W).
A check valve (V26) that allows the refrigerant to flow toward A) is provided. The auxiliary gas line (8a) adjusts the cooling capacity and the heating capacity of both the outdoor units (2A, 2B).

The connecting gas line (10) has a connecting gas passage (10b) connected to the auxiliary gas passage (82) of the auxiliary gas line (8a) and a branched connecting gas having a branch stop valve (V27). The aisle (10c) is connected. One end of the branch connecting gas passage (10c) is connected to the gas passage (57) in the gas line (5LA) on the side of the first outdoor unit (2A), and the other end is in the connecting gas line (10). Connection stop valve
(V4) is connected to the second outdoor unit (2B) side, and the branch stop valve (V27) constitutes a branch opening / closing mechanism that allows bidirectional refrigerant flow. And the branch connecting gas passage
(10c) and the second stop valve (V27) are the above piping unit (1
It is integrated into 1) and unitized. In this embodiment, as in the first embodiment of FIG. 1, each outdoor unit (2A, 2B) is provided with a receiver (27) and a liquid stop valve (V1).

-Operation of Embodiment 6- Next, the operation of the air conditioner (1) shown in FIG. 8 will be described with reference to FIGS. First, when all the indoor units (3, 3, ...) Are in the cooling operation or in the heating operation, they operate similarly to the fifth embodiment shown in FIGS. 6 and 7, and the auxiliary gas line (8a) does not participate in driving motion. Next, in the simultaneous cooling / heating operation, when the demand for the cooling capacity is large, the state is as shown in FIG. For example, this is the case where one indoor unit (3) is in heating operation and all other indoor units (3, 3, ...) Are in cooling operation. At that time, the first outdoor unit (2A) and the second outdoor unit (2A)
The four-way switching valve (22) of (B) is switched to a solid line, the first outdoor unit (2A) and the second outdoor unit (2B) enter the cooling cycle state, and the compressor of the both outdoor units (2A, 2B) The gas refrigerant discharged from (21) is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and most of the liquid refrigerant joins the main liquid line (4L) and the main liquid line (4L ) Will flow. On the other hand, a part of the high pressure gas refrigerant discharged from the compressor (21) of the first outdoor unit (2A) is part of the auxiliary gas line (8a).
Flow from the high pressure auxiliary passage (83) to the main high pressure gas line (4
After passing through H), it flows into the indoor unit (3) in the heating operation, and the high-pressure gas refrigerant is condensed to become a liquid refrigerant. This liquid refrigerant merges with the liquid refrigerant from both the outdoor units (2A, 2B) in the flow divider (45) of the main liquid line (4L) and flows to the indoor units (3, 3, ...) in the cooling operation. , Evaporates to a low-pressure gas refrigerant,
Each outdoor unit (2A, 2A) through the main low pressure gas line (4W)
It returns to the compressor (21) of 2B) and repeats this circulation operation.

Further, when the heating capacity is greatly requested during the simultaneous heating and cooling operation, the operation becomes as shown in FIG. For example, this is a case where one indoor unit (3) is performing cooling operation and all other indoor units (3, 3, ...) Are performing heating operation. At that time, the four-way switching valve (22) of the first outdoor unit (2A) and the second outdoor unit (2B) is switched to a solid line to heat the first outdoor unit (2A) and the second outdoor unit (2B). The high pressure gas refrigerant discharged from the compressors (21) of both outdoor units (2A, 2B) enters the gas line (5GA, 5G
Main high pressure gas line through high pressure passage (57a, 58a) of B)
It joins at (4H) and flows to the indoor units (3,3, ...) In heating operation. And this indoor unit (3,3, ...)
Then, the gas refrigerant is condensed into a liquid refrigerant, and this liquid refrigerant flows into the main liquid line (4L). Then, the liquid refrigerant, in the flow divider (45) of the main liquid line (4L), most of it passes through the main liquid line (4L), the outdoor heat exchanger (24) of each outdoor unit (2A, 2B) Evaporates to become a low-pressure gas refrigerant. On the other hand, in the indoor unit (3) of the cooling operation, a part of the liquid refrigerant is diverted by the flow divider (45) of the main liquid line (4L) and supplied through the branch liquid pipe (41c) to the indoor unit (3). It vaporizes in the unit (3) to become a low pressure gas refrigerant. This low-pressure gas refrigerant flows through the main low-pressure gas line (4W), the low-pressure auxiliary passage (84), the auxiliary gas line (8a), and the first outdoor unit (2A).
Will join the low-pressure gas refrigerant. Then, each low-pressure gas refrigerant, each outdoor unit (2A, 2B) compressor (21)
Then, this circulation operation is repeated.

Further, when both the cooling capacity and the heating capacity are small in the simultaneous heating and cooling operation and the cooling capacity is large, the situation is as shown in FIG. 10. In this case, the second outdoor unit (2B) stops operation. on the other hand,
In the first outdoor unit (2A), the four-way switching valve (22)
Changes to a solid line and enters a cooling cycle state, and the gas refrigerant discharged from the compressor (21) of the first outdoor unit (2A) is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and the main liquid line It will flow through (4L). In addition, a part of the high-pressure gas refrigerant discharged from the compressor (21) of the first outdoor unit (2A) flows into the auxiliary gas line (8a), and from the high-pressure auxiliary passage (83) to the main high-pressure gas line (4H). The high-pressure gas refrigerant condenses into a liquid refrigerant by flowing through the indoor unit (3) in the heating operation. This liquid refrigerant merges with the liquid refrigerant from the first outdoor unit (2A) in the flow divider (45) of the main liquid line (4L),
It flows into the indoor unit (3,3, ...) in the cooling operation, evaporates into a low pressure gas refrigerant, passes through the main low pressure gas line (4W) and returns to the compressor (21) of the first outdoor unit (2A), The circulation operation will be repeated.

Further, in the simultaneous heating and cooling operation, when both the cooling capacity and the heating capacity are small, and the heating capacity is large, the situation is as shown in FIG. 11, and in this case, the same as in FIG. Then, the second outdoor unit (2B) is stopped. On the other hand, in the first outdoor unit (2A), the four-way switching valve (22) is switched to the solid line to enter the heating cycle state, and the high pressure gas refrigerant discharged from the compressor (21) of the first outdoor unit (2A) is It will flow through the main high pressure gas line (4H) through the gas line (5GA) and then to the indoor units (3,3, ...) In heating operation. And this indoor unit (3,3, ...)
Then, the liquid refrigerant is condensed to become a liquid refrigerant, and this liquid refrigerant flows into the main liquid line (4L). Then, the liquid refrigerant, in the flow divider (45) of the main liquid line (4L), mostly passes through the main liquid line (4L), in the outdoor heat exchanger (24) of the first outdoor unit (2A) Evaporate to a low pressure gas refrigerant. Also, in the indoor unit (3) for cooling operation, a part of the liquid refrigerant is diverted by the flow divider (45) of the main liquid line (4L), and the branch liquid pipe
It is supplied through (41c) and evaporated in the indoor unit (3) to become a low pressure gas refrigerant. The low-pressure gas refrigerant passes through the main low-pressure gas line (4W), the low-pressure auxiliary passage (84) and the auxiliary gas line (8a), and joins with the low-pressure gas refrigerant of the first outdoor unit (2A). After that, the low-pressure gas refrigerants described above return to the compressor (21) of the first outdoor unit (2A) and repeat this circulation operation.

Also in this embodiment, as in the fifth embodiment shown in FIGS. 6 and 7, when the demands for the cooling capacity and the heating capacity are balanced, the first outdoor unit (2A) cools the cooling cycle. In the state, the second outdoor unit (2B) enters the heating cycle state or the opposite state, and the simultaneous cooling / heating operation is executed.

When the operation of the second outdoor unit (2B) is stopped, the liquid stop valve (V1) is closed and the receiver (2B) is closed.
Prevent the accumulation of liquid refrigerant in 7) etc. That is, since the liquid refrigerant pressure during operation is higher than the saturation pressure equivalent to the outside air temperature, there is a possibility that the liquid refrigerant will accumulate in the receiver (27), so this accumulation is prevented. Furthermore, when the second outdoor unit (2B) is stopped, the second outdoor unit (2B) is stopped.
The gas passage (64) of (2B) communicates with the main low pressure gas line (4W) via the refrigerant recovery passage (8b), and the refrigerant of the second outdoor unit (2B) is connected to the main low pressure gas line (4W). To collect the liquid refrigerant in the second outdoor unit (2B).

On the other hand, the connection stop valve (V4) and the branch stop valve (V27), which are the features of the present invention, operate as shown in Table 1.

[Table 1] Specifically, for example, all the indoor units (3, 3, ...) Are cooling-operated to perform the first outdoor unit (2A) and the second outdoor unit (2B).
When both are in the cooling cycle state (see Table 1-), the high pressure reversible valve (V28) and the low pressure reversible valve (V29) are closed, while the connection stop valve (V4) is opened and the branch stop valve (V2
7) is closed, and the high pressure refrigerant pressure on the discharge side and the low pressure refrigerant pressure on the suction side of the compressor (21) in both outdoor units (2A, 2B) become equal. Also, all indoor units (3,3, ...)
If the first outdoor unit (2A) and the second outdoor unit (2B) are both in the heating cycle state due to heating operation (see Table 1-), the high pressure reversible valve (V28) and the low pressure reversible valve (V29) are closed. Meanwhile, the connection stop valve (V4) is opened, the branch stop valve (V27) is closed, and the high pressure refrigerant pressure on the discharge side and the low pressure side on the suction side of the compressor (21) in both outdoor units (2A, 2B). The refrigerant pressures become equal.

Further, during the simultaneous heating / cooling operation in which the indoor units (3, 3, ...) Perform heating operation and cooling operation, the first outdoor unit (2A) enters the cooling cycle state and the second outdoor unit (2B) In the heating cycle state (see Table 1), the high pressure reversible valve (V28) is opened, the low pressure reversible valve (V29) is closed, and the compressor (21) in both outdoor units (2A, 2B) is closed.
The high-pressure refrigerant pressure on the discharge side becomes equal. On the other hand, the connection stop valve (V4) is closed, the branch stop valve (V27) is opened, and the low-pressure refrigerant pressure on the suction side of the compressor (21) in both the outdoor units (2A, 2B) becomes equal. Also, during the simultaneous heating / cooling operation in which the indoor units (3,3, ...) Perform heating operation and cooling operation, the first outdoor unit (2A) enters the heating cycle state and the second outdoor unit (2B) enters the cooling cycle state. (See Table 1), the high pressure reversible valve (V28) is closed, the low pressure reversible valve (V29) is opened, and both outdoor units (2
The low-pressure refrigerant pressure on the suction side of the compressor (21) in A, 2B) becomes equal. On the other hand, the connection stop valve (V4) is closed, the branch stop valve (V27) is opened, and both outdoor units (2
The high-pressure refrigerant pressure on the discharge side of the compressor (21) in A, 2B) becomes equal.

Furthermore, the first outdoor unit (2A) and the second outdoor unit (2A)
When both the outdoor unit (2B) is in the cooling cycle state or the heating cycle state (see Table 1-), as described above, the connection stop valve (V4) opens, so that in the cooling cycle state, the high pressure gas refrigerant is Both the outdoor heat exchangers (24) flow almost uniformly, and in the heating cycle state, the low-pressure gas refrigerant flows through the both outdoor heat exchangers (24) approximately evenly. For example, in the cooling cycle state, the second outdoor unit
When the operating capacity of (2B) becomes larger than the load, the compressor (2B)
Part of the refrigerant discharged from 1) flows through the connecting gas line (10) to the outdoor heat exchanger (24) in the first outdoor unit (2A). Further, in the heating cycle state, when the operating capacity of the second outdoor unit (2B) becomes large with respect to the load, part of the refrigerant drawn into the compressor (21) of the first outdoor unit (2A) is connected to the connecting gas line. It will flow through the (10) to the second outdoor unit (2B).

-Effect of Sixth Embodiment-Accordingly, according to this embodiment, the connecting gas line (10) and the branch connecting gas passage (10c) are provided.
The outdoor unit (2A) is provided with a high pressure sensor (HPS) and a low pressure sensor (LPS), while the second outdoor unit (2B) is connected to the indoor unit (3, 3, ... It is possible to detect the refrigerant pressure of the second outdoor unit (2B) only by providing one common pressure sensor (CSP) in the gas pipe (62) located at (2). That is, the refrigerant pressure of the gas side refrigerant pipe (26) of the outdoor heat exchanger (24) in the second indoor unit (2B) is the high pressure sensor (HPS) and the low pressure sensor (HPS) of the first outdoor unit (2A). LPS) and can be detected. As a result, only the common pressure sensor (CSP) need be provided in the second outdoor unit (2B), the number of parts can be reduced, and the refrigerant flowing through the outdoor heat exchangers (24) can be made almost even. Therefore, the COP (coefficient of performance) can be improved.

Further, since the auxiliary gas line (8a) is provided, the demands of the cooling capacity and the heating capacity are balanced, the demand of the cooling capacity is large, and the heating capacity of the heating capacity is large. When the demand is large and the demand for the heating and cooling capacity is small, the simultaneous cooling and heating operation can be performed. As a result, since the operating range can be expanded, it is possible to deal with various usage conditions. In addition, by providing the above-mentioned auxiliary gas line (8a), only the compressor (21) of the first outdoor unit (2A) is subjected to linear control corresponding to the load by inverter control,
Since the compressor (21) of the outdoor unit (2B) is controlled in three stages of unloading and the operating range can be expanded as described above, various modes can be dealt with by simple control. Other actions and effects are similar to those of the fourth embodiment shown in FIGS. 6 and 7.

-Embodiment 7- FIGS. 12 and 13 show another embodiment, and FIGS.
Check valve of auxiliary gas line (8a) in the sixth embodiment shown in FIG.
A reversible valve (V28, V29) is provided in place of (V25, V26) to share the sensor. That is, the high pressure auxiliary passage (83) in the auxiliary gas line (8a) has a high pressure reversible valve (2) that allows bidirectional refrigerant flow between the first outdoor unit (2A) and the main high pressure gas line (4H). V28) is provided, and a low pressure reversible valve (V29) that allows bidirectional refrigerant flow between the first outdoor unit (2A) and the main low pressure gas line (4W) is provided in the low pressure auxiliary passageway (84). It is provided. The high pressure reversible valve (V28) and the low pressure reversible valve (V29) are connected to the piping unit (1
It is integrated with 1). Further, in the refrigerant pipe (26) on the discharge side of the compressor (21) in the first outdoor unit (2A), a high pressure sensor (HPS) for detecting the discharge refrigerant pressure is provided, and the high pressure sensor (HPS) of the compressor (21) is provided. The suction side refrigerant pipe (26) is provided with a low pressure sensor (LPS) for detecting the suction refrigerant pressure. And, in the second outdoor unit (2B),
Both pressure sensors are omitted. Other than that, the configuration of the connecting gas line (10) and the like is similar to that of the sixth embodiment shown in FIGS.

-Operation of Embodiment 7- Next, the operation of the embodiment shown in FIGS. 12 and 13 will be described. First, when all the indoor units (3, 3, ...) are in the cooling operation and the first outdoor unit (2A) and the second outdoor unit (2B) are in the cooling cycle state, both reversible valves (V28, V2
9) is closed together. Further, as shown in FIG. 12, the four-way switching valve of the first outdoor unit (2A) is operated simultaneously with cooling and heating.
(22) is switched to a solid line to turn the first outdoor unit (2A) into a heating cycle state, and the four-way switching valve of the second outdoor unit (2B)
When (22) is switched to the solid line and the second outdoor unit (2B) is in the cooling cycle state, the high pressure reversible valve (V28) is closed and the low pressure reversible valve (V29) is opened. As a result, in any of the above cases, the low-pressure refrigerant pressure of the second outdoor unit (2B) becomes equal to the low-pressure refrigerant pressure of the first outdoor unit (2A), and the second outdoor unit (2
The low pressure refrigerant pressure of B) will be detected by the low pressure sensor (LPS) of the first outdoor unit (2A). Therefore,
Since the low-pressure refrigerant pressure is common, the excess and deficiency of the cooling capacity is controlled by the combination of the capacity of the compressor (21) in the first outdoor unit (2A) and the capacity of the compressor (21) in the second outdoor unit (2B). can do. Further, the capacity of the compressor (21) and the opening degree of the outdoor electric expansion valve (25) are controlled so that the low-pressure refrigerant pressure does not become an abnormally low pressure due to the uneven flow of the liquid refrigerant.

On the other hand, all the indoor units (3, 3, ...) Are operated by heating and the first outdoor unit (2A) and the second outdoor unit (2B).
Is in the heating cycle, both reversible valves (V2
8, V29) are closed together. In addition, as shown in FIG. 13, the simultaneous cooling and heating operation is performed, and the four-way switching valve (22) of the first outdoor unit (2A) is switched to a solid line so that the first outdoor unit (2A)
Becomes the cooling cycle state, the four-way switching valve (22) of the second outdoor unit (2B) is switched to the solid line, and the second outdoor unit (2B)
Is in the heating cycle, the high pressure reversible valve (V2
8) is opened and the low pressure reversible valve (V29) is closed. As a result, in any of the above cases, the second outdoor unit (2B)
The high pressure refrigerant pressure of the first outdoor unit (2A) is equal to the high pressure refrigerant pressure of the second outdoor unit (2B), which is important during the heating cycle.
Will be detected by the High Pressure Pressure Sensor (HPS). Therefore, since the high-pressure refrigerant pressure is common, the excess or deficiency of the heating capacity is combined with the capacity of the compressor (21) in the first outdoor unit (2A) and the capacity of the compressor (21) in the second outdoor unit (2B). Can be controlled by. Then, the capacity of the compressor (21) and the opening degree of the outdoor electric expansion valve (25) are controlled so that the high-pressure refrigerant pressure does not become an abnormally high pressure.

Other operations in this embodiment are shown in FIG.
Similar to the sixth embodiment shown in FIG. 11, in the operating state of FIGS. 8 and 10, the low pressure reversible valve (V29) is closed and the high pressure reversible valve (V28) is opened. Further, in the operation state of FIG. 9 and FIG. 11, the low pressure reversible valve (V29) is opened and the high pressure reversible valve (V29) is opened.
28) is closed. Further, it goes without saying that the operation shown in FIGS. 6 and 7 can be performed.

-Effect of Embodiment 7- Therefore, according to this embodiment, the high pressure sensor (HPS) is used.
Since the low pressure sensor (LPS) is provided only in the first outdoor unit (2A), the sensor in the second outdoor unit (2B) can be omitted, and the number of parts can be reduced without lowering the control accuracy. Can be reduced. Further, the operating capacity can be adjusted in the same manner as the embodiment shown in FIGS. 8 to 11, and the check valve (V25, V26) is replaced by the reversible valve (V28, V29).
Since the sensor can be shared by simply replacing it with the above, the operating range can be expanded and the number of sensors can be reduced. Other effects are similar to those of the sixth embodiment shown in FIGS.

[Embodiment 8] FIGS. 14 and 15 show another embodiment, which is an embodiment of the invention according to claim 7, which is the sixth embodiment shown in FIGS.
In the embodiment, the pressure equalizing passage (8c) is provided to enable the pressure equalization between the main high pressure gas line (4H) and the main low pressure gas line (4W). That is, the pressure equalizing passage (8c) is the main high pressure gas passage (42b) of the main high pressure gas line (4H).
And the main low-pressure gas passage (4W) of the main low-pressure gas line (4W)
It is connected between 3b) and a pressure equalizing valve (V30) is installed. The pressure equalizing valve (V30) constitutes a pressure equalizing opening / closing mechanism for circulating and blocking the refrigerant from the main high pressure gas passage (42b) to the main low pressure gas passage (43b). The high pressure auxiliary passage (83) and the low pressure auxiliary passage (8
An auxiliary reversible valve (V31) is provided on the first outdoor unit (2A) side from 4), and the auxiliary reversible valve (V31) is a main low pressure gas line.
It constitutes an auxiliary opening / closing mechanism that is closed when the (4W) pressure is equalized to the main high-pressure gas line (4H). The pressure equalizing passage (8c), the pressure equalizing valve (V30) and the auxiliary reversible valve (V31) are integrally provided in the piping unit (11). Other than that, the configuration of the connecting gas line (10) and the like is similar to that of the sixth embodiment shown in FIGS.

-Operation and Effect of Eighth Embodiment- Next, the pressure equalizing operation of the present embodiment will be described. This pressure equalizing operation is performed when switching the operating states of the indoor units (3, 3, ...). For example, in one indoor unit (3), when switching from cooling operation to heating operation, the low pressure valve (72 ) Is closed and the high pressure valve (71) is opened. When the main low-pressure gas line (4W) is equalized to the main high-pressure gas line (4H), the four-way switching valve (22) of the first outdoor unit (2A) is switched to the solid line as shown in FIG. Put the first outdoor unit (2A) into the heating cycle. Further, the operation of the second outdoor unit (2B) is stopped, the auxiliary reversible valve (V31) is closed, and the pressure equalizing valve (V30) is opened. In this state, the high pressure gas refrigerant discharged from the compressor (21) of the first outdoor unit (2A) is
From the gas line (5GB) through the main high-pressure gas line (4H), through the pressure equalizing passage (8c) to the main low-pressure gas line (4W), the main low-pressure gas line (4W) is equalized to a high pressure state. It On the contrary, when equalizing the pressure of the main high-pressure gas line (4H) to the main low-pressure gas line (4W), the operation of both outdoor units (2A, 2B) is stopped and the pressure equalizing valve
Open (V30). In this state, the high-pressure gas refrigerant in the main high-pressure gas line (4H) becomes the main low-pressure gas line (4W).
And the main high pressure gas line (4H) is equalized to a low pressure state. Therefore, according to this embodiment, the pressure equalizing passage (8
Since c) is provided, the main high pressure gas line (4
Since H) and the main low-pressure gas line (4W) can be pressure-equalized, it is possible to reliably prevent generation of vibration and noise due to switching. Other actions and effects are shown in FIG.
~ The same as the sixth embodiment of Fig. 11.

The pressure equalizing passage (8c) of this embodiment may be provided in the seventh embodiment shown in FIGS. 12 and 13, in which case the auxiliary reversible valve (V31) need not be provided.

-Embodiment 9- FIG. 16 shows another embodiment, in which the second outdoor unit (2
B1) is provided with a third outdoor unit (2B2), and the second outdoor unit (2B1) and the third outdoor unit (2
B2) has the same structure as the second outdoor unit (2B) in FIGS. 6 and 8. That is, the second outdoor unit
(2B1) is the same as the connecting gas line (10) and the branch connecting passage (10c) shown in FIG. 6 for the first outdoor unit (2A).
It is connected via a connection gas line (10) having a connection stop valve (V4a) and a branch connection passage (10c) having a branch stop valve (V27a). In addition, the third outdoor unit (2B2)
Similarly, is connected to the first outdoor unit (2A) via a connection gas line (101) having a connection stop valve (V4b) and a branch connection passage (10c1) having a branch stop valve (V27b). There is.

Then, each of the above connection stop valves (V4a, V4b)
And each branch stop valve (V27a, V27b)
Similar to the sixth embodiment, it operates as shown in Table 2 below.

[Table 2] Specifically, for example, at the time of simultaneous heating / cooling operation in which the indoor units (3, 3, ...) Perform heating operation and cooling operation (Table 2- (6)
), The first outdoor unit (2A) enters the cooling cycle state, and the second outdoor unit (2B1) enters the heating cycle state. Then, the third outdoor unit (2B2) enters a cooling cycle state, a heating cycle state, or a stopped state due to fluctuations in the cooling capacity and the heating capacity, and in this cooling cycle state, the connection stop valve (V4b) is opened. , Branch stop valve (V
27b) is closed, and in the heating cycle state, the connection stop valve (V4b) is closed, the branch stop valve (V27b) is opened,
In the stopped state, the connection stop valve (V4b) is closed and the branch stop valve (V27b) is opened. As a result, the high pressure refrigerant pressure on the discharge side and the low pressure refrigerant pressure on the suction side of the compressor (21) in each of the outdoor units (2A, 2B1, 2B2) become equal. Other configurations, actions and effects are shown in FIG.
~ Similar to the sixth embodiment of Fig. 11, but with check valves (V25, V26)
Instead, a reversible valve (V28, V29) shown in FIGS. 12 and 13 is provided.

-Other Embodiments-In each of the embodiments, the air conditioner capable of reversible operation in the heating / cooling cycle has been described. However, the invention of claim 1 may be an air conditioner dedicated to cooling. . As one embodiment in this case, the four-way switching valve (22) and the outdoor electric expansion valve (25) in FIG. 1 are omitted, and the gas stop valve (V2) is omitted, so that the second outdoor Unit (2B)
When the cooling operation of is stopped, the liquid stop valve (V1) is fully closed. Also, in the first to fourth embodiments, three or more outdoor units (2) may be provided. Further, the branch connecting gas passage (10c) of the sixth embodiment may be provided in the fifth embodiment shown in FIGS. 6 and 7. Further, the pressure equalizing passage (8c) of the eighth embodiment may be provided in the fifth embodiment shown in FIGS. 6 and 7.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner showing a first embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram of essential parts showing a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram of an air conditioner showing a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram of an air conditioner showing a modified example of a gas stop valve.

FIG. 5 is a refrigerant circuit diagram of essential parts showing a fourth embodiment of the present invention.

FIG. 6 is a refrigerant circuit diagram on the outdoor unit side showing a fifth embodiment of the present invention.

FIG. 7 is a refrigerant circuit diagram on the indoor unit side showing a fifth embodiment of the present invention.

FIG. 8 is a refrigerant circuit diagram of essential parts showing a sixth embodiment of the present invention.

FIG. 9 is a refrigerant circuit diagram of essential parts showing an operating state of the sixth embodiment.

FIG. 10 is a refrigerant circuit diagram of essential parts showing an operating state of the sixth embodiment.

FIG. 11 is a refrigerant circuit diagram of essential parts showing an operating state of the sixth embodiment.

FIG. 12 is a refrigerant circuit diagram of essential parts showing a seventh embodiment of the present invention.

FIG. 13 is a refrigerant circuit diagram of essential parts showing an operating state of the seventh embodiment.

FIG. 14 is a refrigerant circuit diagram of essential parts showing an eighth embodiment of the present invention.

FIG. 15 is a refrigerant circuit diagram of essential parts showing an operating state of an eighth embodiment.

FIG. 16 is a refrigerant circuit diagram of essential parts showing a ninth embodiment of the present invention.

[Explanation of symbols]

 1 Air conditioner 2A, 2B Outdoor unit (heat source unit) 21 Compressor 24 Outdoor heat exchanger (heat source side heat exchanger) 25 Outdoor electric expansion valve (heat source side expansion mechanism) 26 Refrigerant piping 3A, 3B Indoor unit (use unit) ) 32 Indoor heat exchanger (use side heat exchanger) 33 Indoor electric expansion valve (use side expansion mechanism) 4L Main liquid line 4G Main gas line 4H Main high pressure gas line 4W Main low pressure gas line 5LA, 5LB Liquid line 5GA, 5GB Gas line 8a Auxiliary gas line 8c Pressure equalizing passage 10 Connection gas line 10c Branch connection Gas passage 12 Receiver V1 Liquid stop valve (liquid opening / closing mechanism) V2 Gas stop valve (gas opening / closing mechanism) V4 Connection stop valve (connection opening / closing mechanism) V27 Branch Stop valve (branch opening / closing mechanism) V30 Pressure equalizing valve (equalizing pressure opening / closing mechanism)

Claims (8)

[Claims] 1. A compressor (21) and a heat source side heat exchanger (24) having one end connected to the discharge side of the compressor (21) and the other end connected to a liquid line (5LA, 5LB). A plurality of heat source units (2A, 2B) having a gas line (5GA, 5GB) connected to the suction side of the compressor (21) and the heat source units (2A, 2B) are connected in parallel. The main liquid line (4L) and the main gas line (4G) to which the outer ends of the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are connected, respectively, and the use side expansion mechanism (33) And a use side heat exchanger (32), a plurality of use units (3A, 3B) connected in parallel to the main liquid line (4L) and the main gas line (4G), and the plurality of A liquid opening / closing mechanism (V1 which is provided in the liquid line (5LB) of at least one heat source unit (2B) of the two heat source units (2A, 2B) and is fully closed when the cooling operation of the heat source unit (2B) is stopped. ) And both ends Each heat source unit (2A, 2B) is connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24), and when the cooling operation of at least one heat source unit (2B) is stopped, the stopped heat source unit (2B ), And a connection gas line (10) having a connection opening / closing mechanism (V4) for preventing the refrigerant from flowing into the refrigeration system. 2. A compressor (21), one end of which is switchably connected to the discharge side and the suction side of the compressor (21) and the other end of which is a liquid line.
(5LA, 5LB) having a heat source side heat exchanger (24) connected to the liquid line (5LA, 5LB) has a heat source side expansion mechanism (25), the compressor (21) of Gas line on discharge side and suction side
(5GA, 5GB) First heat source unit (2
A) and the second heat source unit (2B) and the outer end side of each liquid line (5LA, 5LB) and each gas line (5GA, 5GB) so that the respective heat source units (2A, 2B) are connected in parallel. It has a main liquid line (4L) and a main gas line (4G) that are connected to each other, and a use side heat exchanger (32), and is connected in parallel to the main liquid line (4L) and the main gas line (4G). A plurality of connected usage units (3A, 3B) and a liquid line (5LB) on the side of the second heat source unit (2B) are provided, and when the operation of the second heat source unit (2B) is stopped, the liquid line (5
The liquid open / close means (V1) for closing the LB) and the gas line (5GB) on the second heat source unit (2B) side are fully closed when the heating operation of the second heat source unit (2B) is stopped. The gas opening / closing mechanism (V2) and both ends are connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B), and at least one heat source unit (2B) is cooled. A refrigerating apparatus comprising: a connecting gas line (10) having a connecting opening / closing mechanism (V4) for blocking the flow of the refrigerant to the stopped heat source unit (2B) when the operation is stopped. 3. A compressor (21), one end of which is switchably connected to the discharge side and the suction side of the compressor (21) and the other end of which is a liquid line.
(5LA, 5LB) having a heat source side heat exchanger (24) connected to the liquid line (5LA, 5LB) has a heat source side expansion mechanism (25), the compressor (21) of Gas line on discharge side and suction side
(5GA, 5GB) First heat source unit (2
A) and the second heat source unit (2B), the main liquid line (4L) to which the outer ends of the liquid lines (5LA, 5LB) of the heat source units (2A, 2B) are connected, respectively, and the first heat source It has a main gas line (4G) to which the outer end of the gas line (5GA) of the unit (2A) is connected, and a heat exchanger (32) on the use side, and the main liquid line (4L) and the main gas line (4G). ), A plurality of utilization units (3A, 3B) connected in parallel, and the heat source side heat exchanger (24) in the first heat source unit (2A)
The gas line side refrigerant pipe (26) of the branch line (5
a) and the main gas line (4G) and the branch line (5a) are connected, and a constant high pressure passage (91) that is always kept in a high pressure state and a constant low pressure passage (92) that is always kept in a low pressure state. Have, second
The gas line (5GB) on the heat source unit (2B) side is connected to the constant high pressure passage (91) so that the refrigerant can flow from the gas line (5GB) toward the high pressure passage (91). 2 Gas line (5GB) on the heat source unit (2B) side is always in the low pressure passage
A constant pressure circuit (9) continuously connected to the low pressure passage (92) so that the refrigerant can flow from (92) to the gas line (5 GB), and a liquid line (5LB) on the second heat source unit (2B) side. Is installed in the liquid line (5) when the operation of the second heat source unit (2B) is stopped.
The liquid opening / closing means (25) for closing the LB) and both ends are connected to the gas side refrigerant pipe (26) of the heat source side heat exchanger (24) in each heat source unit (2A, 2B), and at least one heat source unit (2B) when the cooling operation is stopped, a refrigeration apparatus characterized by comprising a connection gas line (10) having a connection opening / closing mechanism (V4) for blocking the refrigerant flow to the stopped heat source unit (2B) . 4. A compressor (21), one end of which is switchably connected to the discharge side and the suction side of the compressor (21) and the other end of which is a liquid line.
(5LA, 5LB) has a heat source side heat exchanger (24) connected, and the liquid line (5LA, 5LB) has a heat source side expansion mechanism (25), from the compressor (21) Of the gas line (5GA, 5GB) branched into the high pressure passage (57a, 58a) that allows the refrigerant to flow in the discharge direction and the low pressure passage (57b, 58b) that allows the refrigerant to flow in the suction direction of the compressor (21). A plurality of heat source units whose base ends are switchably connected to the discharge side and the suction side of the compressor (21) (2A,
2B) and each liquid source (5LA, 5LB), each high pressure passage (57a, 58a) and each low pressure passage (57b, 58b) are connected so that each heat source unit (2A, 2B) is connected in parallel. The main liquid line (4
L), a main high-pressure gas line (4H) and a main low-pressure gas line (4W), a utilization side heat exchanger (32) whose one end is connected to the main liquid line (4L), and the utilization side heat exchanger ( 32) and the main liquid line (4
L) and the utilization side expansion mechanism (33) provided between the other side of the utilization side heat exchanger (32) the main high pressure gas line (4H) and the main low pressure gas line (4W) A plurality of utilization units (3, 3, ...) Switchably connected to the gas source refrigerant pipe (26) of the heat source side heat exchanger (24) in one heat source unit (2A). A gas line refrigerant pipe (26) of the heat source side heat exchanger (24) in the heat source unit (2B) is provided so as to communicate with each other, and a connecting gas line having a connecting opening / closing mechanism (V4) that allows bidirectional refrigerant flow ( 10) A refrigerating device comprising: 5. A compressor (21), one end of which is switchably connected to the discharge side and the suction side of the compressor (21) and the other end of which is a liquid line.
(5LA, 5LB) has a heat source side heat exchanger (24) connected, and the liquid line (5LA, 5LB) has a heat source side expansion mechanism (25), from the compressor (21) Of the gas line (5GA, 5GB) branched into the high pressure passage (57a, 58a) that allows the refrigerant to flow in the discharge direction and the low pressure passage (57b, 58b) that allows the refrigerant to flow in the suction direction of the compressor (21). A plurality of heat source units whose base ends are switchably connected to the discharge side and the suction side of the compressor (21) (2A,
2B) and each liquid source (5LA, 5LB), each high pressure passage (57a, 58a) and each low pressure passage (57b, 58b) are connected so that each heat source unit (2A, 2B) is connected in parallel. The main liquid line (4
L), a main high-pressure gas line (4H) and a main low-pressure gas line (4W), a utilization side heat exchanger (32) whose one end is connected to the main liquid line (4L), and the utilization side heat exchanger ( 32) and the main liquid line (4
L) and a use side expansion mechanism (33) provided between the other side of the use side heat exchanger (32) the main high pressure gas line (4H) and the main low pressure gas line (4W) Source heat exchanger in a plurality of utilization units (3,3, ...), which are switchably connected to each other, and a heat source unit (2A) with one end
(24) is connected to the gas side refrigerant pipe (26), and the other end is connected to the main high pressure gas line (4H) and the main low pressure gas line (4W), the heat source unit (2A) and the main high pressure gas line ( 4H) and a high-pressure auxiliary passage (83) that allows the refrigerant to flow between the main low pressure gas line (4W) and the heat source unit (2A) and a low-pressure auxiliary passage that allows the refrigerant to flow between the auxiliary (84) The gas line (8a) and the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in one heat-source unit (2A) to the heat-source-side heat exchanger (24) in the other heat-source unit (2B) And a connection gas line (10) having a connection opening / closing mechanism (V4) which is provided so that the gas side refrigerant piping (26) of the same communicates with each other and allows bidirectional refrigerant flow. . 6. The refrigeration apparatus according to claim 4 or 5, wherein the gas line (5G) in the heat source unit (2A) has one end.
A branching opening / closing mechanism that communicates with A) and has the other end connected between the other heat source unit (2B) and the connecting opening / closing mechanism (V4) in the connecting gas line (10) to allow bidirectional refrigerant flow ( V27)
A refrigerating apparatus comprising a branch connecting gas passage (10c) having 7. The refrigeration system according to claim 4, wherein the main high pressure gas line (4H) and the main low pressure gas line (4W).
And a pressure equalizing passage (8c) having a pressure equalizing opening / closing mechanism (V30) for circulating and blocking the refrigerant from the main high pressure gas line (4H) to the main low pressure gas line (4W). Refrigerating device characterized in that 8. The refrigerating apparatus according to any one of claims 1 to 7, wherein a receiver (12) connecting each liquid line (5LA, 5LB) and a main liquid line (4L) includes each liquid line (5LA). , 5LB) and the main liquid line (4L) are connected to each other.