JP3351099B2 - Refrigeration equipment - Google Patents

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 a measure for improving the refrigerating operation efficiency.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 4-208370, an air conditioner as a refrigerating device has a plurality of indoor units connected in parallel to one outdoor unit by a refrigerant pipe. There are connected multi-types. 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.

During the cooling operation, the refrigerant discharged from the compressor is condensed in the outdoor heat exchanger, decompressed by the indoor electric expansion valve, and then circulated so as to evaporate in the indoor heat exchanger and return to the compressor. During the heating operation, the refrigerant discharged from the compressor is condensed in the indoor heat exchanger, decompressed by the outdoor electric expansion valve, and then circulated so as to evaporate in the outdoor heat exchanger and return to the compressor.

In the above outdoor unit, the capacity of the compressor is controlled in accordance with the load of the indoor unit.

[0005]

In the above-described air conditioner, only one outdoor unit is conventionally provided, so that various types of capacities are required according to the indoor load, that is, the number of connected indoor units. There is a problem that the outdoor unit must be manufactured. 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 despite the small indoor load.

Accordingly, it is conceivable to combine a plurality of outdoor units having different capacities, for example, two outdoor units in a multi-type.

[0007] At this time, the capacity of the compressor of each outdoor unit may be different, resulting in a problem that efficiency is poor.

That is, the compressor of one outdoor unit is 10
In the state where the compressor is operating at 0%, the compressor of another outdoor unit may be operating at 50%, and if the supercooling control is not performed during the cooling operation, the outdoor unit having a large refrigerant circulation amount may be used. On the outlet side of the outdoor heat exchanger, flashing occurs, and conversely, in an outdoor unit having a small amount of circulating refrigerant, there is a problem that excessive cooling is excessively large.

Further, in the outdoor heat exchanger of each outdoor unit, 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.

[0010] The present invention has been made in view of the above points, and is intended to allow the refrigerant to flow evenly to the heat exchangers of the respective heat source units and to share the sensor.

[0011]

Means for Solving the Problems In order to achieve the above-mentioned object, a means adopted by the present invention is that 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. It is.

More specifically, the means implemented by the invention according to claim 1 includes 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 (5LA, 5LA). 5LB) and a plurality of heat source units (2A, 2B) having a heat source side heat exchanger (24) connected to a gas line (5GA, 5GB) on the suction side of the compressor (21). Is provided.

The main liquid to which the outer ends of the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are connected so that the heat source units (2A, 2B) are connected in parallel. A line (4L) and a main gas line (4G) are provided, and a use-side expansion mechanism (33) and a use-side heat exchanger (32) are provided, and the main liquid line (4L) and the main gas line are provided.
(4G) multiple units connected in parallel (3
A, 3B) are provided.

Further, the plurality of 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 of each heat source unit (2
A, 2B), the gas-side refrigerant pipe (2
6) and at least the cooling of all heat source units (2A, 2B)
Allows refrigerant flow during chamber operation and one heat source unit (2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) for preventing refrigerant flow to the stopped heat source unit (2B) when the cooling operation is stopped is provided.

As shown in FIG. 1, the means according to the second aspect of the present invention can first switch between a compressor (21) and one end between a discharge side and a suction side of the compressor (21). Heat source side heat exchanger connected to the liquid line and the other end connected to the liquid line (5LA, 5LB)
(24) and a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB), and a gas line (5GA, 5GB) is provided on the discharge side and the suction side of the compressor (21). Is switchably connected to the first
A heat source unit (2A) and a second heat source unit (2B) are provided.

A main liquid line to which the outer ends of the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are connected so that the heat source units (2A, 2B) are connected in parallel. (4L) and a main gas line (4G), and a use side heat exchanger (32).
L) and a plurality of utilization units (3A, 3B) connected in parallel to the main gas line (4G).

Further, the liquid line (5LB) on the side of the second heat source unit (2B) 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 a gas switching mechanism (V2) that is fully closed when the heating operation of the second heat source unit (2B) is stopped. .

In addition, both ends of each heat source unit (2
A, 2B), the gas-side refrigerant pipe (2
6) and at least the cooling of all heat source units (2A, 2B)
Allows refrigerant flow during chamber operation and one heat source unit (2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) for preventing refrigerant flow to the stopped heat source unit (2B) when the cooling operation is stopped is provided.

As shown in FIG. 5, the means according to the third aspect of the present invention can first switch between a compressor (21) and one end between a discharge side and a suction side of the compressor (21). Heat source side heat exchanger connected to the liquid line and the other end connected to the liquid line (5LA, 5LB)
(24) and a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB), and a gas line (5GA, 5GB) is provided on the discharge side and the suction side of the compressor (21). Is switchably connected to the first
A heat source unit (2A) and a second heat source unit (2B) are provided.

A main liquid line (4L) to which an outer end of each liquid line (5LA, 5LB) of each heat source unit (2A, 2B) is connected, and a gas line of the first heat source unit (2A). A main gas line (4G) to which the outer end side of the (5GA) is connected is provided, and a use side heat exchanger (32) is provided, and the main liquid line (4L) and the main gas line (4G) are provided. A plurality of use 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. (4G) and the branch line (5a) are connected, and have a constantly high-pressure passage (91) always maintained in a high-pressure state and a constantly low-pressure passage (92) always maintained in a low-pressure state, and the second heat source unit ( The gas line (5GB) on the 2B) side is connected to the high-pressure passage (91) so that the refrigerant can always flow from the gas line (5GB) toward the high-pressure passage (91), and the second heat source unit (2
A constant-pressure circuit (9) connected to the low-pressure passage (92) is provided so that the gas line (5GB) on the B) side can always flow refrigerant from the low-pressure passage (92) toward the gas line (5GB). ing.

In addition, the liquid line (5LB) on the side of the second heat source unit (2B) has a liquid opening / closing means (25) for closing the liquid line (5LB) when the operation of the second heat source unit (2B) is stopped. Is provided.

In addition, both ends of each heat source unit (2
A, 2B), the gas-side refrigerant pipe (2
6) and at least the cooling of all heat source units (2A, 2B)
Allows refrigerant flow during chamber operation and one heat source unit (2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) for preventing refrigerant flow to the stopped heat source unit (2B) when the cooling operation is stopped is provided.

Further, as shown in FIGS. 6 and 7, the means taken by the invention according to claim 4 first includes a compressor (21),
A 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); , 5LB), and a high-pressure passage (57a, 58a) for allowing refrigerant to flow in the discharge direction from the compressor (21).
(21) low-pressure passages (57b, 58b) permitting refrigerant flow in the suction direction.
b) a plurality of heat source units (2A, 2B) whose base ends of the gas lines (5GA, 5GB) are switchably connected to the discharge side and the suction side of the compressor (21). Have been.

Each liquid line (5LA, 5LB) and each high-pressure passage are connected so that each heat source unit (2A, 2B) is connected in parallel.
(57a, 58a) and a main liquid line (4L), a main high-pressure gas line (4H), and a main low-pressure gas line (4W) to which the low-pressure passages (57b, 58b) are connected, respectively. User-side heat exchanger with one end connected to (4L)
(32), a use-side expansion mechanism (33) provided between the use-side heat exchanger (32) and the main liquid line (4L), and the use-side heat exchanger (32) The other end is connected to the main high pressure gas line (4
H) and a plurality of use units (3, 3, ...) switchably connected to the main low-pressure gas line (4W).

In addition, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) of one heat-source unit (2A) is connected to the heat-source-side heat exchanger (24) of another heat-source unit (2B). A gas-side refrigerant pipe (26) is provided so as to communicate with at least
A connection gas line (10) having a connection opening / closing mechanism (V4) that allows bidirectional refrigerant flow during cooling operation and heating operation of all the heat source units (2A, 2B ) is provided.

As shown in FIG. 8, the means adopted by the invention according to claim 5 is that, first, the compressor (21) and one end can be switched between the discharge side and the suction side of the compressor (21). Heat source side heat exchanger connected to the liquid line and the other end connected to the liquid line (5LA, 5LB)
(24) and a heat-source-side expansion mechanism (25) provided in the liquid lines (5LA, 5LB), and a high-pressure passage (57a, 58a) that allows refrigerant to flow in the discharge direction from the compressor (21). ) And low pressure passages (57b, 58b) allowing refrigerant flow in the suction direction of the compressor (21).
There are provided a plurality of heat source units (2A, 2B) that are switchably connected to the discharge side and the suction side of the heat source unit.

Each liquid line (5LA, 5LB) and each high-pressure passage are connected so that the heat source units (2A, 2B) are connected in parallel.
(57a, 58a) and a main liquid line (4L), a main high-pressure gas line (4H), and a main low-pressure gas line (4W) to which the low-pressure passages (57b, 58b) are connected, respectively. User-side heat exchanger with one end connected to (4L)
(32), a use-side expansion mechanism (33) provided between the use-side heat exchanger (32) and the main liquid line (4L), and the use-side heat exchanger (32) The other end is the main high pressure gas line (4
H) and a plurality of use units (3, 3, ...) switchably connected to the main low-pressure gas line (4W).

Further, 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 (4H) and the main low pressure gas line. Line (4W), a high-pressure auxiliary passage (83) that allows refrigerant flow between the heat source unit (2A) and the main high-pressure gas line (4H), and the main low-pressure gas line (4W) and the heat source unit ( An auxiliary gas line (8a) having a low-pressure auxiliary passage (84) that allows the refrigerant to flow to and from 2A) is 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 heat source side heat exchanger (24) in the other heat source unit (2B). A gas-side refrigerant pipe (26) is provided so as to communicate with at least
A connection gas line (10) having a connection opening / closing mechanism (V4) that allows bidirectional refrigerant flow during cooling operation and heating operation of all the heat source units (2A, 2B ) is provided.

Further, the means taken by the invention according to claim 6 is that, in the invention according to claim 4 or 5, one end communicates with the gas line (5GA) in one heat source unit (2A),
And a branch connection having a branch opening and closing mechanism (V27) connected between the other heat source unit (2B) and the connection opening and closing mechanism (V4) in the connection gas line (10) and allowing bidirectional refrigerant flow. A gas passage (10c) is provided.

[0033] Further, the means adopted by the invention according to claim 7 is that, in the invention according to any one of claims 4 to 6, the main high pressure gas line (4H) and the main low pressure gas line (4W) are connected. A pressure equalizing passage (8c) having a pressure equalizing opening / closing mechanism (V30) for connecting and blocking the refrigerant from the main high-pressure gas line (4H) to the main low-pressure gas line (4W) is provided.

[0034] In the invention according to the eighth aspect, in the invention according to any one of the first to seventh aspects, each liquid line (5LA, 5LB) is connected to the main liquid line (4L). A receiver (12) is provided at a connection between the liquid lines (5LA, 5LB) and the main liquid line (4L).

[0035]

According to the first aspect of the present invention,
First, the high-pressure gas refrigerant discharged from the compressor (21) of each heat source unit (2A, 2B) condenses in the heat source side heat exchanger (24) to become a liquid refrigerant, and this liquid refrigerant is supplied to the main liquid line (4L). To join. In particular, in the invention according to claim 8, the refrigerant is the receiver (1).
Merge in 2). Thereafter, the liquid refrigerant is supplied to the utilization side expansion mechanism.
After being decompressed in (33), it evaporates in the use side heat exchanger (32) to become a low-pressure gas refrigerant.
A, 5GB) and the compressor (2A) of each heat source unit (2A, 2B).
Returning to 1), the cooling operation is performed by repeating this circulation operation. When the cooling operation of the one heat source unit (2B) is stopped, the liquid opening / closing mechanism (V1) is closed to prevent accumulation of the liquid refrigerant.

The gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat-source units (2A, 2B) communicates via the connecting gas line (10). Exchanger (2
4) The circulation amount of the refrigerant flowing through becomes almost equal, and the COP (coefficient of performance) is improved.

According to the second aspect of the present invention, first, during the cooling operation, the compressor of each heat source unit (2A, 2B)
The high-pressure gas refrigerant discharged from (21) is a heat source side heat exchanger (24)
To condense into a liquid refrigerant, which is the main liquid line
(4L) to join. In particular, in the invention according to claim 8, the refrigerant joins at the receiver (12). Thereafter, the liquid refrigerant is decompressed by a use-side expansion mechanism or the like, and then evaporates in a use-side heat exchanger (32) to become a low-pressure gas refrigerant, which is divided into gas lines (5GA, 5GB). Then, the flow returns to the compressor (21) of each heat source unit (2A, 2B), and this circulation operation is repeated.

Further, during the heating operation, the high-pressure gas refrigerant discharged from the compressor (21) of each of the heat source units (2A, 2B) merges in the main gas line (4G), and then,
(3A, 3B). Then, this gas refrigerant is condensed in the use side heat exchanger (32) to become a liquid refrigerant, and this liquid refrigerant flows from the main liquid-liquid line (4L) to the liquid line (5LA) on each heat source unit (2A, 2B) side. , 5LB). In particular, in the invention according to claim 8, the refrigerant is divided by the receiver (12). Thereafter, the liquid refrigerant is decompressed by the heat source side expansion mechanism (25), and then evaporated by the heat source side heat exchanger (24) to become a low pressure gas refrigerant, and the compressor (21A) of each heat source unit (2A, 2B). ) To repeat this circulating operation.

When the heating operation in the second heat source unit (2B) is stopped, the gas switching mechanism (V2) is closed,
Further, when the cooling operation and the heating operation in the second heat source unit (2B) are stopped, the liquid opening / closing mechanism (V1) is closed,
The liquid refrigerant is prevented from accumulating in the stopped second heat source unit (2B), and the shortage of the refrigerant amount between the first heat source unit (2A) and the utilization units (3A, 3B) is prevented.

In particular, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat source units (2A, 2B) communicates via the connecting gas line (10), so At any time during the heating operation, the circulation amount of the refrigerant flowing through each heat source side heat exchanger (24) becomes almost equal, and the COP (coefficient of performance) is improved.

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) is provided between the gas line (5 GB) 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). Will flow. Accordingly, the gas switching mechanism (V
Without the provision of 2), accumulation of the liquid refrigerant in the second heat source unit (2B) is prevented.

In the invention according to claim 4, when each of the utilization units (3, 3,...) Performs the cooling operation, the heat source units (2A, 2B) enter a cooling cycle state, and the respective heat source units (2A, The high-pressure gas refrigerant discharged from the compressor (21) of 2B)
The liquid refrigerant is condensed in the heat source side heat exchanger (24) to become a liquid refrigerant, and this liquid refrigerant joins in the main liquid line (4L). Thereafter, the liquid refrigerant is diverted to each of the usage units (3, 3, ...), and in each of the usage units (3, 3, ...), the pressure of the liquid refrigerant is reduced by the usage-side expansion mechanism (33). Thereafter, the gas refrigerant evaporates in the use-side heat exchanger (32) to become a low-pressure gas refrigerant. The gas refrigerant passes through the main low-pressure gas line (4W) and is divided into the low-pressure passages (57b, 58b). And, the above gas refrigerant is supplied to each gas line (5GA, 5GB)
Then, the operation returns to the compressor (21) of each heat source unit (2A, 2B), and this circulation operation is repeated.

On the other hand, when each of the utilization units (3, 3,...) Performs a heating operation, the heat source units (2A, 2B) enter a heating cycle state and discharge from the compressor (21) of each heat source unit (2A, 2B). The high-pressure gas refrigerant passes through the gas lines (5GA, 5GB), joins from the high-pressure passages (57a, 58a) to the main high-pressure gas line (4H), and is then split into the use units (3, 3, ...). . In each of the utilization units (3, 3, ...), the gas refrigerant is condensed in the utilization-side heat exchanger (32) to become a liquid refrigerant. This liquid refrigerant passes through the main liquid line (4L) and
The liquid is diverted to the liquid passages (53, 54) on the (2A, 2B) side. After that, the liquid refrigerant is decompressed by the heat source side expansion mechanism (25), and then evaporated by 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 circulating operation is repeated.

During the cooling operation, for example, when one utilization unit (3) performs the heating operation, simultaneous cooling and heating operation is performed. In the simultaneous cooling and heating operation, one heat source unit (2A) is used for the cooling operation. A cycle state is established, and the other heat source unit (2B) enters a heating cycle state. The high-pressure gas refrigerant discharged from the compressor (21) of the one heat source unit (2A) is condensed by the heat source side heat exchanger (24) to become a liquid refrigerant, and a part of the liquid refrigerant or all of the liquid refrigerant Is another heat source unit (2B)
After being decompressed, it is evaporated in the heat source side heat exchanger (24) and flows into the compressor (21) to be compressed.

Thereafter, 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), and uses the heating operation in the same manner as in the heating operation described above. Flow to the unit (3,3, ...).

Subsequently, the heating operation units (3,
The liquid refrigerant condensed in (3, ...) flows into the main liquid line (4L)
And flows to the indoor unit in the cooling operation in the same manner as in the cooling operation described above.

After that, the liquid refrigerant evaporates in the cooling operation use units (3, 3,...) To become a low-pressure gas refrigerant, passes through the main low-pressure gas line (4W), and enters the heat source unit (2A) in the cooling cycle state. Then, the circulation operation is repeated, and the simultaneous cooling and heating operation is performed.

When the heat source units (2A, 2B) are in the same cycle operation, 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 (2
The refrigerant flowing through the heat source side heat exchangers (A, 2B) of the heat exchanger (24) is almost uniform, and the COP (coefficient of performance) is improved.

Further, in the invention according to claim 6, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat source units (2A, 2B) is branched in addition to the connecting gas line (10). Each heat source unit (2
A, 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 each heat source unit
The high pressure sensor or the low pressure sensor or both sensors in (2A, 2B) can be used in common.

According to a fifth aspect of the present invention, in addition to the operation of the fourth aspect of the invention, for example, when simultaneous cooling and heating operations require a large cooling capacity, the compression of one heat source unit (2A) A 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 uses the heating operation units (3, 3, ...).
And the high-pressure gas refrigerant is condensed to become a liquid refrigerant. This liquid refrigerant is supplied to both heat source units in the main liquid line (4 L).
The liquid refrigerant from (2A, 2B) merges and flows to the cooling operation utilization unit (3, 3, ...).

In the simultaneous cooling and heating operation, if the demand for the heating capacity is large, a part of the liquid refrigerant is supplied from the main liquid line (4L) to the cooling operation use unit (3). It evaporates in (3) and becomes a low-pressure gas refrigerant. This low-pressure gas refrigerant passes through the main low-pressure gas line (4W), flows through the auxiliary gas line (8a), and
It will merge with the low-pressure gas refrigerant of (2A).

According to a seventh aspect of the present invention, in addition to the operation of the fourth aspect of the present invention, a main low-pressure gas line is provided.
When equalizing the pressure of (4W) to the main high-pressure gas line (4H), the first heat source unit (2A) is set to a heating cycle state. Further, the operation of the other heat source unit (2B) is stopped, and the pressure equalizing passage (8c) is connected. In this state, the high-pressure gas refrigerant discharged from the compressor (21) of the heat source unit (2A)
From the gas line (5LA) through the main high-pressure gas line (4H), through the 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, the main high-pressure gas line (4H)
When the pressure is 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 connected. In this state, the high-pressure gas refrigerant in the main high-pressure gas line (4H) flows into the main low-pressure gas line (4W), and the main high-pressure gas line (4H) is equalized to a low-pressure state.

[0054]

Therefore, according to the first aspect of the present invention,
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) Since the refrigerant flowing through each heat source side heat exchanger (24) can be made substantially uniform, the COP (coefficient of performance) can be improved.

Further, since the heat source units (2A, 2B) can share the high pressure sensor during the cooling operation, the number of parts can be reduced.

Further, a liquid opening / closing mechanism (V1) is provided in the liquid line (5LB) of at least one heat source unit (2B) so that the liquid opening / closing mechanism (V1) is completely closed when cooling operation is stopped. For this reason, the liquid refrigerant can be prevented from accumulating in the stopped heat source unit (2B), so that the shortage of the refrigerant amount between the other heat source units (2A) and the utilization units (3A, 3B) can be prevented. Can be prevented.

As a result, a plurality of heat source units (2A, 2B)
Can be combined. In addition, heat source units (2A, 2B) with different capacities were manufactured, and the heat source units (2
A, 2B) can be combined, so that a small number of heat source units (2A, 2B) can cope with various types of loads.

According to the second aspect of the present invention, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat-source units (2A, 2B) communicates. Since the refrigerant flowing through each heat source side heat exchanger (24) can be made substantially uniform, the COP (coefficient of performance) can be improved, and the cooling operation in each parent heat source unit (2A, 2B) can be performed. Since the high pressure sensor and the low pressure sensor during the heating operation can be shared, the number of parts can be reduced.

Further, 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 to the first heat source unit (2A).

The gas line of the second heat source unit (2B)
(5 GB) is provided with a gas switching mechanism (V2), and the liquid line (5LB) is provided with a liquid switching mechanism (V1), and when the cooling operation and the heating operation of the second unit (2B) are stopped, the liquid switching mechanism (V1) When the heating operation of the second heat source unit (2B) is stopped
In order to close (V2), it is possible to prevent the liquid refrigerant from accumulating in the stopped second heat source unit (2B), for example, to prevent the liquid refrigerant from accumulating in the receiver or the like. be able to. In other words, the liquid refrigerant pressure during operation is
Although the pressure is higher than the saturation pressure corresponding to the outside air temperature and the liquid refrigerant may accumulate in the receiver or the like, the accumulation can be prevented.

Further, it is possible to prevent a shortage of the refrigerant amount between the first heat source unit (2A) and the utilization units (3A, 3B), and to prevent the shortage of the sub heat source unit (2B) when the child heat source unit (2B) is restarted. Liquid compression can be prevented.

As a result, a plurality of heat source units (2A, 2B)
Can be combined. In addition, heat source units (2A, 2B) with different capacities were manufactured, and the heat source units (2
A, 2B) can be combined, so that a small number of heat source units (2A, 2B) can cope with various types of loads.

Further, in the invention according to claim 3, the constant pressure circuit
In order to provide (9), the second outdoor unit (2B)
Is stopped, the high-pressure gas refrigerant does not flow into the second outdoor unit (2B), so that accumulation of the liquid refrigerant can be prevented. Further, since the gas opening / closing mechanism (V2) according to the second aspect of the present invention can be omitted, the configuration can be simplified.

According to the fourth aspect of the present invention, similarly to the second aspect of the present invention, each heat source unit (2A, 2B) is provided with the gas of each heat source side heat exchanger (24) during the same cycle operation. Since the refrigerant flowing through the heat source-side heat exchangers (24) of the heat source units (2A, 2B) can be made almost uniform because the side refrigerant pipes (26) are communicated, the COP Coefficient) can be improved.

Further, since a plurality of heat source units (2A, 2B) are provided, it is not necessary to use a dedicated heat source unit corresponding to the simultaneous cooling and heating operation system, so that each heat source unit (2A, 2B) Thus, various uses can be supported.

In particular, since only the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are extended from the heat source units (2A, 2B), a so-called simultaneous cooling / heating operation is not performed. Since it can be used as a normal heat source unit, various operations can be performed with a small number of models, and a highly versatile heat source unit (2A, 2B) can be obtained.

Further, heat source units (2A, 2B) having different capacities
And the heat source units (2A, 2B) can be combined, so that a small number of types of heat source units (2A, 2B)
Can handle a plurality of indoor units (3, 3,...), That is, it can correspond to various types of loads.

According to the fifth aspect of the present invention, since the auxiliary gas line (8a) is provided, in addition to the case where the requirements of the cooling capacity and the heating capacity are balanced, the case where the demand of the cooling capacity is large In addition, even when the demand for the heating capacity is large and the demand for the cooling and heating capacity is small, the simultaneous cooling and heating operation can be performed. As a result, since the operation range can be expanded, it is possible to cope with various use states.

Also, by providing the auxiliary gas line (8a), only the compressor (21) of one heat source unit (2A) is controlled linearly according to the load by inverter control.
Since the compressor (21) of the other heat source unit (2B) is subjected to three-stage unload control and the operation range can be expanded as described above, various modes can be dealt with with simple control.

According to the invention of claim 6, the gas-side refrigerant pipe (26) of the heat-source-side heat exchanger (24) in each of the heat source units (2A, 2B) is connected to the connecting gas line (10) and the branch connection. Since the communication is established by the gas passage (10c), 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) can be equalized. The high pressure sensor or the low 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 sensor and the low-pressure sensor only in one heat source unit (2A), the sensors of the other heat source units (2B) can be omitted. The number of parts can be reduced.

According to the seventh aspect of the present invention, since the equalizing passage (8c) is provided, the main high-pressure gas line is switched when the cooling / heating operation is switched in the use unit (3).
(4H) and the main low-pressure gas line (4W) can be equalized, so that generation of vibration and noise due to switching can be reliably prevented.

According to the invention of claim 8, each heat source unit (2) is provided by providing one receiver (12).
Since the receivers A and 2B) can be omitted, the number of parts can be reduced. Further, since the liquid refrigerant can be surely divided, even if the flash gas flows through the main liquid line (4L) or the like, the drift can be reliably prevented.

[0073]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 shows an embodiment according to the second aspect of the present invention.
(1) is an air conditioner as a refrigerating device, 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).

The outdoor unit (2A, 2B) comprises a compressor (21)
A four-way switching valve (22), an outdoor heat exchanger (24) that 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) that is a heat source side expansion mechanism. To form a heat source unit. A refrigerant pipe (26) is provided at one end of the outdoor heat exchanger (24) on the gas side, and a liquid line (5) is provided at the other end of the liquid side.
LA, 5LB) are connected 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 is connected to the liquid lines (5LA, 5LB). From the outdoor heat exchanger (24), the outdoor electric expansion valve (25) and a receiver (27) for storing a liquid refrigerant are provided in this order and connected to the main liquid line (4L).

Further, a gas line (5) is connected to the compressor (21).
GA, 5GB) is connected via a refrigerant pipe (26), and the gas line (5GA, 5GB) is connected to the compressor (21) by a four-way switching valve (22).
Are switchably connected to the suction side and the discharge side, and are connected to the main gas line (4G). Then, the refrigerant pipe (2) between the suction side of the compressor (21) and the four-way switching valve (22)
6) is provided with an accumulator (28).

The indoor units (3A, 3B) include an indoor heat exchanger (32), which is a use side heat exchanger in which an indoor fan (31) is arranged in proximity, and an indoor electric expansion, which is a use side expansion mechanism. valve
(33) to constitute a utilization unit, wherein the indoor heat exchanger
(32) is connected to the main liquid line (4L) and the main gas line (4G) via the indoor liquid pipe (34) and the indoor gas pipe (35), and the indoor electric expansion is connected to the indoor liquid pipe (34). A valve (33) is provided.

On the other hand, the two outdoor units (2A, 2B)
Is a device in which a first outdoor unit (2A) serving as a parent outdoor unit and a second outdoor unit (2B) serving as a child outdoor unit are connected in parallel. The capacity of each outdoor unit (2A, 2B)
The indoor load, that is, the compressor (21) of the first outdoor unit (2A) is set according to the number of connected indoor units (3A, 3B), and the compressor (21) of the first outdoor unit (2A) is controlled by an inverter. The compressor (21) of (2B) is configured for unload control which can be switched between 100% capacity, 50% capacity and 0% capacity.

Further, various sensors are provided in the first outdoor unit (2A) and the indoor units (3A, 3B). The first outdoor unit (2A) includes a discharge gas temperature sensor (Th1) for detecting a discharge gas refrigerant temperature of the compressor (21).
In the discharge side refrigerant pipe (26) of (21), a suction gas temperature sensor (Th2) for detecting a suction gas refrigerant temperature of the compressor (21) is connected to the compressor (21).
An outdoor liquid temperature sensor (Th3) that detects the liquid refrigerant temperature on the outdoor heat exchanger (24) side is connected to the liquid line (5LA) in the suction side refrigerant pipe (26).
An outdoor air temperature sensor (Th4) for detecting an outdoor air temperature is provided in the vicinity of the outdoor heat exchanger (24), respectively, and a high pressure sensor (HPS) for detecting a suction refrigerant pressure of the compressor (21).
A low-pressure pressure sensor (LPS) that detects the suction refrigerant pressure of the compressor (21) is connected to the discharge-side refrigerant pipe (26) of the compressor (21).
The suction side refrigerant pipes (26) of 1) are provided respectively.

Each of the indoor units (3A, 3B) includes:
An indoor liquid temperature sensor (Th5) that detects the liquid refrigerant temperature on the indoor heat exchanger (32) side is connected to the indoor liquid pipe (34), and an indoor gas temperature sensor that detects the gas refrigerant temperature on the indoor heat exchanger (32) side (Th6) is connected to the indoor gas pipe (35) by a room temperature sensor (T
h7) are provided near the indoor fans (31), respectively.

Then, the above sensors (Th1 to Th7, HPS, LP
S) is input to the controller (6), and the controller (6) detects the opening degree and the opening degree of each electric expansion valve (25, 33) based on the detection signal of each sensor (Th1 to Th7, HPS, LPS). Compressor (21)
Is 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 line (5LA, 5LB) on each of the outdoor units (2A, 2B). ) And gas lines (5GA, 5GB) are connected to the main liquid line (4L) and the main gas line (4G).

Specifically, the liquid lines (5LA, 5LB) are connected to liquid tubes (51, 52) extending outward from the outdoor units (2A, 2B).
And a liquid passage (53, 54) continuous with the outer end of the liquid pipe (51, 52). The liquid pipe (51, 52) has an inner end connected to the outdoor heat exchanger (24). Connected and the outdoor electric expansion valve (25)
And a receiver (27).

The gas lines (5GA, 5GB) are provided with gas pipes (55, 56) extending outward from the outdoor units (2A, 2B), and gas passages (55, 56) connected to the outer ends of the gas pipes (55, 56). 57, 58), and the gas pipes (55, 56) are connected to the compressor (21) via a four-way switching valve (22).

The main liquid line (4L) is connected to the main liquid pipe (41) extending toward the indoor unit (3A, 3B), and connected to one end of the main liquid pipe (41) and connected to the outdoor unit (2A). , 2B)
Side liquid passages (53, 54) are constituted by a continuous main liquid passage (42), and the other end of the main liquid pipe (41) is connected to the indoor unit
The indoor liquid piping (34) of (3A, 3B) is connected.

The main gas line (4G) is connected to the main gas pipe (43) extending toward the indoor unit (3A, 3B), and connected to one end of the main gas pipe (43) and connected to the outdoor unit (2).
Main gas passage with continuous gas passages (57, 58) on the A, 2B) side
(44), and the other end of the main gas pipe (43) is connected to the indoor gas pipe (35) of the indoor unit (3A, 3B).

The piping unit (11) is provided with a liquid passage (53, 54) of a liquid line (5LA, 5LB) and a gas passage (5GA, 5GB) of a gas line (5GA, 5GB) on each outdoor unit (2A, 2B) side. 57,5
8), the main liquid passage (42) of the main liquid line (4L) and the main gas passage (44) of the main gas line (4G) are integrally formed as a unit.

Further, in the piping unit (11), a liquid stop valve (V1) and a gas stop valve (V2) are integrally unitized. The gas stop valve (V2) is connected to the gas passage (58) in the gas line (5 GB) on the side of the second outdoor unit (2B).
And a gas opening / closing mechanism that opens and closes the gas passage (58) .The gas stop valve (V2) further includes a gas passage (58) on the second outdoor unit (2B) side and a main gas line. (4G)
Located close to the connection with the main gas passage (44) of the
The second outdoor unit (2B) is configured to be fully closed when the second outdoor unit (2B) is stopped during the heating operation based on the control signal of the controller (6).

The liquid stop valve (V1) is provided in a liquid passage (54) in the liquid line (5LB) on the second outdoor unit (2B) side to open and close the liquid passage (54). Wherein the liquid stop valve (V1) is provided with the second outdoor unit (2B).
Side liquid passage (54) and main liquid line (4L)
2) placed close to the connection with the controller
Based on the control signal of (6), the second outdoor unit (2B) is configured to be fully closed when the second outdoor unit (2B) is stopped during the cooling and heating operations.

The compressor (2) is connected to the second outdoor unit (2B).
A bypass line (29) 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 provided. The controller (6) includes a second outdoor unit (2B)
Immediately after the heating operation is stopped, 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) in the open state for a predetermined time, for example, 1 to 2 minutes, and the first outdoor unit (2A).
A refrigerant discharging means (61) for discharging to the side is provided.

Further, the controller (6) is provided with a refrigerant amount detecting means (62) and a refrigerant collecting means (63). The refrigerant amount detecting means (62) detects that the outdoor electric expansion valve (25) of the first outdoor unit (2A) is fully open and the outdoor liquid temperature is in the heating operation and when the second outdoor unit (2B) is stopped. Sensor (Th
3) When the superheat degree of the refrigerant of the outdoor heat exchanger (24) based on the detection signal of the suction gas temperature sensor (Th2) becomes equal to or higher than a predetermined temperature, it is configured to detect the refrigerant quantity shortage.

The refrigerant collecting means (63) is a refrigerant amount detecting means.
When (62) detects the shortage of the refrigerant amount, 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 squeezed for a predetermined time. To reduce the liquid refrigerant to a saturation pressure equivalent to the outside air temperature,
The liquid refrigerant of the stopped second outdoor unit (2B) is configured to evaporate and recover. Incidentally, the refrigerant recovery means (63)
When the outdoor electric expansion valve (25) of the stopped second outdoor unit (2B) is not open, the outdoor electric expansion valve (25) is also opened for a predetermined time.

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 connecting gas line (10) 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 connected to the second outdoor unit (2B). ) Is connected to the gas-side refrigerant pipe (26) of the outdoor heat exchanger (24). Further, the connection gas line (10) is connected to a connection gas pipe (10) extending outside each outdoor unit (2A, 2B).
A connecting gas passage (10b) is continuously formed at the outer end of a), and the connecting gas passage (10b) is fully closed when the cooling operation of the second outdoor unit (2B) is stopped. Outdoor unit (2B)
A connection stop valve (V4), which is a connection opening / closing mechanism for preventing the refrigerant from flowing to the air, is provided.

The connecting gas passage (10b) and the connecting stop valve (V4) are integrated into the piping unit (11) to form a unit.

-Operation of Embodiment 1- Next, the control operation of the air conditioner (1) will be described.

First, during the cooling operation, the four-way switching valve
(22) changes to the broken line in FIG. 1, and the high-pressure gas refrigerant discharged from the compressor (21) of both outdoor units (2A, 2B) is supplied to the outdoor heat exchanger.
The liquid refrigerant is condensed in (24) to become 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 by the indoor heat exchanger (32) to become a low-pressure gas refrigerant. (57, 58), return to the compressor (21) of each outdoor unit (2A, 2B), and repeat this circulation operation.

On the other hand, during the heating operation, the four-way switching valve (22) is switched to the solid line in FIG.
The high-pressure gas refrigerant discharged from the compressor (21) of (B) flows into the piping unit (11), and the main gas passage of the piping unit (11)
After merging at (44), it flows to the indoor units (3A, 3B). Then, the gas refrigerant is condensed in the indoor heat exchanger (32) to become a liquid refrigerant, and this liquid refrigerant flows from the main liquid passage (42) of the piping unit (11) to the outdoor units (2A, 2B). Liquid passage (5
3, 54). Thereafter, the liquid refrigerant is decompressed by the outdoor electric expansion valve (25), and then evaporates in the outdoor heat exchanger (24) to become a low-pressure gas refrigerant, and the compressor (21) of each outdoor unit (2A, 2B) To repeat this circulating operation.

At the time of the cooling operation and the heating operation,
The controller (6) controls the degree of opening of each indoor electric expansion valve (33) and each outdoor electric expansion valve (25), and the compressor (21) in each outdoor unit (2A, 2B) according to the indoor load. Control the capacity of Specifically, the controller (6)
100% capacity and 50% compressor (21) of outdoor unit (2B)
In addition to controlling the capacity, the capacity of the compressor (21) of the first outdoor unit (2A) is controlled substantially linearly according to the load by inverter control. Then, the indoor unit (3
If the load on the first outdoor unit (2A) is reduced by the load of the first outdoor unit (2A), the operation of the second outdoor unit (2B) is stopped.

Further, the controller (6) closes the liquid stop valve (V1) when the cooling operation and the heating operation of the second outdoor unit (2B) are stopped, and stops 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 the liquid refrigerant is higher than the saturation pressure corresponding to the outside air temperature, the liquid refrigerant may accumulate in the receiver (27), so that the accumulation is prevented.

The controller (6) closes the gas stop valve (V2) when the heating operation of the second outdoor unit (2B) is stopped, and the liquid refrigerant accumulates in the stopped second outdoor unit (2B). And prevent shortage of the amount of refrigerant between the first outdoor unit (2A) and the outdoor units (2A, 2B).

Further, immediately after the heating operation of the second outdoor unit (2B) is stopped, the refrigerant discharge means (61) is connected to the bypass stop valve (V3) and the outdoor electric expansion valve (25) of the second outdoor unit (2B). ), The liquid stop valve (V1) and the gas stop valve (V2) are kept open for a predetermined time, for example, for 1-2 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 stopped second outdoor unit (2B)
The liquid refrigerant in (2B) is discharged to the main liquid line (4L) or the like to prevent a shortage of the refrigerant amount.

That is, when the refrigerant flows through the main gas line (4G) or the like, the pressure of the refrigerant decreases due to the pressure loss. However, during the heating operation, the indoor unit (3A, 3B) does not have the same length as the pipe length. The difference in pressure loss is corrected by the indoor electric expansion valve (33). As a result, since the refrigerant pressure in the main liquid line (4L) becomes smaller 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.

During the stoppage of the heating operation of the second outdoor unit (2B), the refrigerant amount detecting means (62) detects whether or not the refrigerant amount is insufficient, that is, the first outdoor unit (2A).
The outdoor electric expansion valve (25) is fully open and the outdoor liquid temperature sensor
(Th3) and the refrigerant superheat degree of the outdoor heat exchanger (24) based on the detection signal of the suction gas temperature sensor (Th2) becomes equal to or higher than a predetermined temperature,
Detects a refrigerant shortage.

When the refrigerant amount detecting means (62) detects a shortage of the refrigerant amount, the refrigerant collecting means (63) sets the liquid stop valve (V
1) is opened for a predetermined time, and the indoor electric expansion valve (3) is opened.
3) is squeezed for a predetermined time to reduce the liquid refrigerant to a saturated pressure corresponding to the outside air temperature, evaporate the liquid refrigerant of the stopped second outdoor unit (2B), and collect the refrigerant to the first outdoor unit (2A). Note that, at this time, the refrigerant recovery means (63) does not operate the outdoor electric expansion valve (25) when the outdoor electric expansion valve (25) in the stopped second outdoor unit (2B) is not open. It is opened for a predetermined time.

Further, as a feature of the present invention, both the outdoor units (2) are used in both the cooling operation and the heating operation.
(A, 2B) is operating, the connection stop valve (V4) is open, and during the cooling operation, the high-pressure gas refrigerant flows almost equally through both outdoor heat exchangers (24), and during the heating operation, As a result, the low-pressure gas refrigerant flows almost evenly through both outdoor heat exchangers (24).

For example, during the cooling operation, when the operating capacity of the second outdoor unit (2B) becomes larger than the load, a part of the refrigerant discharged from the compressor (21) is connected to the connecting gas line (10).
Through the outdoor heat exchanger (2) in the first outdoor unit (2A).
4) will flow.

Further, during the heating operation, if the operating capacity of the second outdoor unit (2B) becomes larger than the load, the first outdoor unit (2B)
Part of the refrigerant from the outdoor heat exchanger (24) in the outdoor unit (2A) passes through the connecting gas line (10), and the second outdoor unit (2
It will be sucked into the compressor (21) of B).

When the cooling operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) is fully closed, and the gas stop valve (V2) is opened as described above.
The refrigerant of the second outdoor unit (2B) is sucked into the low pressure side of the first outdoor unit (2A).

When the heating operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) is kept open, and the gas stop valve (V2) is fully closed as described above. The refrigerant of the second outdoor unit (2B) is connected to the connecting gas line (1
0) and is sucked into the low pressure side of the first outdoor unit (2A).

-Effect of Embodiment 1- Therefore, according to the present embodiment, the first outdoor unit (2A)
Gas-side refrigerant pipe (26) of the outdoor heat exchanger (24) and the second
In order to communicate with the gas-side refrigerant pipe (26) of the outdoor heat exchanger (24) in the outdoor unit (2B), the refrigerant flowing through each outdoor heat exchanger (24) should be approximately equalized. Therefore, the COP (coefficient of performance) can be improved.

Further, since the high pressure sensor for the cooling operation and the low pressure sensor for the heating operation in each outdoor unit (2A, 2B) can be shared, 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) is kept open, so that the refrigerant in the stopped second outdoor unit (2B) can be reliably discharged. It can be collected in the first outdoor unit (2A).

Further, since a gas stop valve (V2) is provided in the gas line (5 GB) on the side of the second outdoor unit (2B), the second
When heating operation of the outdoor unit (2B) is stopped, the gas stop valve (V
2) can be closed to prevent liquid refrigerant from accumulating in the stopped second outdoor unit (2B), and the first outdoor unit
The shortage of the refrigerant amount between (2A) and the indoor units (3A, 3B) can be prevented.

Further, since the liquid line (5LB) on the side of the second outdoor unit (2B) is provided with the liquid stop valve (V1), the cooling operation and the heating operation in the second outdoor unit (2B) are stopped. By closing the liquid stop valve (V1), accumulation of the liquid refrigerant in the receiver (27) and the like can be prevented.

As a result, a plurality of outdoor units (2A, 2B)
Can be combined. Also, outdoor units (2A, 2B) with different capacities were manufactured, and two outdoor units (2A, 2B)
Can be combined, so that a small number of outdoor units (2A, 2B) can be used for a plurality of indoor units (3A, 3B).

Since the refrigerant discharging means (61) is provided, immediately after the heating operation of the second outdoor unit (2B) is stopped, the high-pressure gas refrigerant is supplied to the liquid line (5LB) on the second outdoor unit (2B) side. ), And the second outdoor unit (2
Since the liquid refrigerant in B) can be discharged to the main liquid line (4L) or the like, the shortage of the refrigerant amount can be reliably prevented.

In addition, when the refrigerant amount detecting means (62) and the refrigerant collecting means (63) are provided, when the refrigerant amount is detected to be insufficient,
The indoor electric expansion valve (33) is squeezed to lower the liquid refrigerant to a saturated pressure corresponding to the outside air temperature, evaporate the liquid refrigerant of the stopped second outdoor unit (2B) and transfer the refrigerant to the first outdoor unit (2A). Due to the recovery, the shortage of the refrigerant amount can always be reliably prevented.

The piping connection between each outdoor unit (2A, 2B) and each indoor unit (3A, 3B) is connected to the piping unit (11).
In addition, it is possible to reliably maintain the inclination angle of the pipe required for the return of the oil and the like, and to surely keep the horizontal pipe at the place where the horizontal pipe is required. As a result, it is possible to reliably return the oil, prevent the liquid refrigerant from being flushed, and perform a highly reliable air-conditioning operation. Furthermore, since the number of pipes for installing two outdoor units (2A, 2B) can be reduced, the number of man-hours for piping work can be reduced, and the work can be simplified.

Embodiment 2 As shown in FIG. 2, in this embodiment, one receiver (12) is provided in a piping unit (11). The receiver
(12) is arranged at a connection portion 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 each outdoor unit is in a cooling operation. The liquid refrigerant from (2A, 2B) is joined to the main liquid line (4L), and the liquid refrigerant from the main liquid line (4L) is distributed to each outdoor unit (2A, 2B) during the heating operation. .

At this time, the receiver (27) in FIG. 1 is omitted from each of the outdoor units (2A, 2B), and instead of closing the liquid stop valve (V1), an outdoor electric expansion valve (25) is provided. Since it is fully closed, the liquid stop valve (V1) is omitted. When the operation of the second outdoor unit (2B) is stopped, the outdoor electric expansion valve (25) of the second outdoor unit (2B) is controlled to be fully closed to constitute a liquid opening / closing mechanism.

The second outdoor unit (2B) is connected to the auxiliary bypass line (29) in parallel with the bypass line (29).
a) is provided. The auxiliary bypass line (29a) is provided with a check valve (V5) that allows 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),
When the heating operation of the outdoor unit (2B) is stopped, the refrigerant of the second outdoor unit (2B) is drawn into the low pressure side of the first outdoor unit (2A) through the connecting gas line (10). At this time, the four-way switching valve (22) may be stopped in the cooling cycle as shown by the solid line in FIG. 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, the receiver of each outdoor unit (2A, 2B) can be omitted by providing one receiver (12), so that the number of parts can be reduced.

Further, since the liquid refrigerant can be surely divided, even if the flash gas flows through the main liquid line (4L) or the like, the drift can be reliably prevented.

In addition, the structure of the connecting gas line (10), etc., and the functions and effects are the same as 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) that can flow 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.

In addition, the configuration of the connecting gas line (10), etc., and the functions and effects are the same as those of the second embodiment shown in FIG. Note that the bypass stop valve (V3) is configured bidirectionally and the auxiliary bypass line (29a) is omitted.

FIG. 4 shows an external pressure equalizing type reversing valve (1a) showing another modification of the gas stop valve (V2). Is connected to a pilot circuit (14). The pilot circuit (14) includes a check valve (V8, V9) and is connected to the main gas line (4G) and the main liquid line (4L) to guide the high-pressure refrigerant. 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.

Although not shown, the external pressure equalizing type reversible valve (1a) comprises a valve body and a pilot valve. The valve body is connected to a gas passage (58) on the second outdoor unit (2B) side. The gas passage (58) is switched between a communicating state and a closed state.

On the other hand, the pilot valve is connected to the high pressure circuit.
(14a) and the low-pressure circuit (14b) are connected, and high or low pressure is guided to the valve body by the control signal of the controller (6), and the gas passage (58) is communicated or shut off.

In addition, the structure of the connecting gas line (10) and the operation and effects are the same as those of the previous embodiment of FIG.

Embodiment 4 FIG. 5 shows another embodiment, which is an embodiment of the present invention according to claim 3, and which is applied to the gas stop valve (V2) in the second embodiment shown in FIG. Instead, branch line (5a) and constant pressure circuit
(9) is provided.

The branch line (5a) is connected to the first outdoor unit (2
A) A branch passageway (5c) is continuously formed at an outer end of a branch pipe (5b) extending outward from the outside pipe, and an inner end of the branch pipe (5b) is connected to an outdoor heat exchanger in the first outdoor unit (2A). (24) and four-way selector valve
(22) is connected to the refrigerant pipe (26). The outer end of the branch passage (5c) is connected to a constant pressure circuit (9).

On the other hand, the constant pressure circuit (9) is always a high pressure passage.
(91) and an always-low pressure passage (92), and one end of each of the always-high pressure passage (91) and the always-low pressure passage (92) has a check valve (V12, V1
The other end is connected to the main passage (44) of the main gas line (4G) via a four-way switching valve (V14). Above regular high pressure passage (9
The check valve (V12) of (1) is connected from the branch passage (5c) to the constant high-pressure passage.
(91) to allow refrigerant flow and always check valve in low pressure passage (92)
(V13) is configured to allow the refrigerant to flow from the low-pressure passage (92) to the branch passage (5c). Further, the four-way switching valve (V14) is switched to a broken line during the cooling operation, the low-pressure gas refrigerant is always switched to the low-pressure passage (92), during the heating operation is switched to a solid line, the high-pressure gas refrigerant is always switched to the high-pressure passage (91) It is configured to lead to.

Further, the main gas passage (44) and the gas passage (58) on the side of the second outdoor unit (2B) allow the refrigerant to flow toward the high pressure passage (91) at all times. Check valve
(V15, V16) and is always kept in a high pressure state. The constant low pressure passage (92) is connected to the main gas passage (44) and the gas passage (58) on the second outdoor unit (2B) side. It is connected to the main gas passage (44) and the gas passage (58) via check valves (V17, V18) that allow the refrigerant to flow, and is always kept at a low pressure.

The constant pressure circuit (9) and the branch passage (5c)
Are integrated into the piping unit (11) to form a unit.

-Effect of Embodiment 4- Therefore, the above constant pressure circuit
(9) and the refrigerant recovery passage (8a), the gas passage (58) of the second outdoor unit (2B) is connected to the connecting gas line when the second outdoor unit (2B) stops during the heating operation. (10) and the low-pressure side of the first outdoor unit (2A) through the low-pressure passage (92), and the accumulation of the liquid refrigerant in the second outdoor unit (2B) is prevented. Further, since the gas stop valve (V2) in FIG. 2 can be omitted, the number of parts can be reduced.

In addition, since the refrigerant discharge means (61) and the refrigerant recovery means (63) can be omitted as in the embodiment shown in FIG. 1, the structure can be further simplified.

In addition, the structure of the connecting gas line (10) and the operation and effects are the same as those of the second embodiment shown in FIG. 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, wherein two outdoor units (2A, 2B) and a plurality of indoor units (3, 3, 3) are provided. ..) 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).

The outdoor units (2A, 2B) are constructed in the same manner as in the second embodiment shown in FIG.
9) and the auxiliary bypass line (29a) are not shown.

The gas lines (5GA, 5GB) are switchably connected to the suction side and the discharge side of the compressor (21) by a four-way switching valve (22), and the main high pressure gas line (4H) And it is connected to the main low pressure gas line (4W).

The indoor units (3, 3,...) Are constructed in the same manner as the second embodiment shown in FIG. 2, except that the indoor gas pipe (35) is connected to the indoor high-pressure pipe (36). Low pressure piping (37)
And 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 pipe (34), a part of the indoor gas pipe (35), the indoor high-pressure pipe (36), and the indoor low-pressure pipe (37) are connected to a pipe kit (7). Are formed integrally.

The piping kit (7) includes a high pressure valve (71) and a low pressure valve.
(72) and a low-pressure bypass (73) and a high-pressure bypass (74). The high-pressure valve (71) is provided in the indoor high-pressure pipe (36), 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) are connected to the indoor heat exchanger (32).
The communication between the main high-pressure gas line (4H) and the main low-pressure gas line (4W) has been switched, and the indoor heat exchanger (32)
When the device functions as an evaporator (during cooling), the low pressure valve (72)
When functioning as a condenser (at the time of heating), the high-pressure valves (71) are opened.

Further, 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), and is connected to the bypass valve (75) and the capillary (73). 76)
And a pipe heat exchanger (77) is formed between the pipe and the indoor liquid pipe (34). And the low pressure bypass passage
(73) prevents the liquid refrigerant flowing out of the indoor heat exchanger (32) from being flushed during the heating operation.

The high-pressure bypass (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 bypasses the condensate that accumulates in the indoor high-pressure pipe (36) during cooling.

On the other hand, the piping unit (11) is the same as the first embodiment.
Unlike the fourth embodiment, the liquid lines (5LA, 5LB) and gas lines (5GA, 5GB) and the main liquid line (4L), the main high-pressure gas line (4H), and the main low-pressure line on each outdoor unit (2A, 2B) side Connected to gas line (4W).

Specifically, similarly to the second embodiment, the liquid lines (5LA, 5LB) are provided with liquid pipes (51, 52) extending outward from the outdoor units (2A, 2B) and the liquid pipes (5LA, 5LB). Liquid passages (53, 54) connected to the outer ends of the gas lines (5, 52).
A, 5 GB) is composed of a gas pipe (55, 56) extending outward from the outdoor unit (2A, 2B), and a gas passage (57, 58) connected to the outer end of the gas pipe (55, 56). Have been. Further, the gas passages (57, 58) are composed of a high pressure passage (57a, 58a) and a low pressure passage (57b,
58b), and the high-pressure passages (57a, 58a) allow refrigerant to flow from the compressor (21) in the discharge direction. Gas line
Check valves (V21, V22) are provided to allow refrigerant flow toward (4H).

The low pressure passages (57b, 58b) are
Check valves (V23, V24) are provided to allow refrigerant flow in the suction direction of (21) and specifically allow refrigerant flow from the main low-pressure gas line (4W) to the outdoor units (2A, 2B). ing.
That is, the outdoor unit (2A, 2B) has two extended liquid tubes (51, 52) and gas tubes (55, 56), and is configured as a dedicated outdoor unit of the simultaneous cooling and heating operation system. Absent.

The main liquid line (4L) is an indoor unit
The main liquid pipe (41a) extending to the (3, 3,...) Side and the liquid in the liquid lines (5A, 5B) connected to one end of the main liquid pipe (41a) and on the outdoor unit (2A, 2B) side. The main liquid passage (41b) is connected to the passages (51, 52). The main liquid pipe (41a) is connected to the branch liquid pipe (41c, 41c,
...), and each of the branch liquid pipes (41c) is connected to the indoor unit.
(3, 3, ...) are connected to the indoor liquid pipe (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,...).
And a main high-pressure gas passage (57a, 58a) connected to one end of the main high-pressure gas pipe (42a) and connected to a high-pressure passage (57a, 58a) in a gas line (5GA, 5GB) on each of the outdoor units (2A, 2B). Four
2b). The main high-pressure gas pipe (42a) is branched into branch high-pressure pipes (42c, 42c,...) Via a flow divider (45), and each of the branch high-pressure pipes (42c) is connected to the indoor unit (3, 3, 3).
..) Is connected to the indoor high-pressure pipe (36).

The main low-pressure gas line (4W) is connected to the main low-pressure gas pipe (43a) extending toward the indoor unit (3, 3,...).
And a main low-pressure gas passage (57b, 58b) connected to one end of the main low-pressure gas pipe (43b) and connected to the low-pressure passage (57b, 58b) in the gas line (5GA, 5GB) on each of the outdoor units (2A, 2B). Four
3b).

The main low-pressure gas pipe (43a) is branched into branch low-pressure pipes (43c, 43c,...) Via a flow divider (45), and each of the branch low-pressure pipes (43c) is connected to the indoor unit (3, 3). , ...) are connected to the indoor low-pressure pipe (37).

The piping unit (11) is connected to the liquid passages of the liquid lines (5LA, 5LB) and the gas passages (57, 58) of the gas lines (5GA, 5GB) on the outdoor unit (2A, 2B) side. The main liquid passage (41b) of the main liquid line (4L), the main high pressure gas passage (42b) of the main high pressure gas line (4H), and the main low pressure gas passage (43b) of the main low pressure gas line (4W). It is integrally formed with the check valves (V21 to V24) to form a unit.

On the other hand, as a feature of the present invention, similarly to 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.

The connecting gas line (10) 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 connected to the second outdoor unit (2B). ) Is connected to the gas-side refrigerant pipe (26) of the outdoor heat exchanger (24). Further, the connection gas line (10) is connected to a connection gas pipe (10) extending outside each outdoor unit (2A, 2B).
A connecting gas passage (10b) is continuously formed at the outer end of a), and the connecting gas passage (10b) is fully closed when the cooling operation of the second outdoor unit (2B) is stopped. Outdoor unit (2B)
A connection stop valve (V4), which is a connection opening / closing mechanism for preventing the refrigerant from flowing to the air, is provided.

The connecting gas passage (10b) and the connecting stop valve (V4) are integrated into the piping unit (11) to form a unit.

-Operation of Embodiment 5- Next, a control operation in the air conditioner (1) will be described.

First, when the indoor units (3, 3,...) Are operated for cooling, the four-way switching valve (22) is switched to the solid line in FIG. 6, and the compressor (21) of both outdoor units (2A, 2B) is switched. ) Is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant,
This liquid refrigerant is supplied to the main liquid passage (41b) of the piping unit (11).
To join. Thereafter, the liquid refrigerant is divided into the indoor units (3, 3,...) By the flow divider (45), while being divided into the indoor units.
In (3, 3, ...), the high pressure valve (71) is closed and the low pressure valve (7
2), the liquid refrigerant is supplied to the indoor electric expansion valve (33)
After being depressurized in the indoor heat exchanger (32), it evaporates into a low-pressure gas refrigerant, which passes from the indoor low-pressure pipe (37) through the main low-pressure gas line (4W) and passes through the pipe unit (11). The flow branches to each of the low pressure passages (67, 68). The gas refrigerant is supplied from each gas line (5GA, 5GB) to each outdoor unit (2A, 2G).
Returning to the compressor (21) of B), this circulation operation is repeated.

When the indoor units (3, 3,...) Are operated for heating, the four-way switching valve (22) is switched to a broken line in FIG. 6 and the compressors of both outdoor units (2A, 2B) are operated. The high-pressure gas refrigerant discharged from (21) passes through the gas line (5GA, 5GB), joins from the high-pressure passages (57a, 58a) to the main high-pressure gas passage (42b) in the piping unit (11), and then branches. The water is divided into the indoor units (3, 3, ...) by the vessel (45). In each of the indoor units (3, 3,...), The high-pressure valve (71) is opened and the low-pressure valve (72) is closed, so that the gas refrigerant passes through the indoor high-pressure pipe (36) and The liquid refrigerant is condensed in the heat exchanger (32) to become a liquid refrigerant.

The liquid refrigerant passes through the main liquid line (4L) and is diverted from the main liquid passage (41b) of the piping unit (11) to the liquid passages (53, 54) on the outdoor unit (2A, 2B) side. You. Thereafter, the liquid refrigerant is reduced in pressure by the outdoor electric expansion valve (25), and then evaporates in the outdoor heat exchanger (24) to become a low-pressure gas refrigerant,
Returning to the compressor (21) of each outdoor unit (2A, 2B), this circulation operation is repeated.

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 the heating operation. When,
Conversely, during the heating operation, for example, the high pressure valve (71) and the low pressure valve (72) of one indoor unit (3) are switched, and
When the indoor units (3) perform the cooling operation, the simultaneous cooling and heating operation is performed.

In this simultaneous cooling and heating operation, the four-way switching valve (22) of the first outdoor unit (2A) is switched to a solid line in FIG. 6 and the first outdoor unit (2A) enters a cooling cycle state. The four-way switching valve (22) of the second outdoor unit (2B) is switched to the broken line in FIG. 1, and the second outdoor unit (2B) enters the heating cycle state. Then, the compressor (2) of the first outdoor unit (2A)
The high-pressure gas refrigerant discharged from 1) is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and the liquid refrigerant is supplied to the piping unit (11).
And part or all of the liquid refrigerant flows through the liquid passage (54) on the second outdoor unit (2B) side to the second outdoor unit (2B), and the outdoor electric expansion valve (25 After being decompressed in the step (2), it is evaporated in the outdoor heat exchanger (24) and flows into the compressor (21) to be compressed. Thereafter, 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) in the same manner as in the heating operation described above. Flows through the main high-pressure gas line (4H) to the indoor units (3, 3,...) For heating operation.

Subsequently, the indoor unit (3,
The liquid refrigerant condensed in the indoor heat exchanger (32) in (3, ...)
Flow divider (4) through the branch liquid pipe (41c) of the main liquid line (4L)
5). At this time, if 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 for heating operation
The liquid refrigerant from (3, 3, ...) merges, and this liquid refrigerant passes through the branch liquid pipe (41c) and, similarly to the above-described cooling operation, the indoor unit (3, 3, ...) in the cooling operation. Flows to

After that, the liquid refrigerant evaporates in the indoor unit (3, 3,...) Of the cooling operation to become a low-pressure gas refrigerant, passes through the main low-pressure gas line (4W), and passes through the low-pressure gas refrigerant of the first outdoor unit (2A). Returning to the compressor (21) of the first outdoor unit (2A) via the gas line (6A), the circulation operation is repeated, and the simultaneous cooling and heating operation is performed.

In the simultaneous cooling and heating operation described above,
When the first outdoor unit (2A) is in the cooling cycle state,
The outdoor unit (2B) was brought into the heating cycle state, but the four-way switching valve (22) of the first outdoor unit (2A) was switched to the broken line in FIG. 1 to bring the first outdoor unit (2A) into 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 supplied to the outdoor heat exchanger (24).
The liquid refrigerant is condensed to form a liquid refrigerant, and a part or all of the liquid refrigerant flows to the first outdoor unit (2A) and evaporates to
It is compressed in (21) and flows through the main high-pressure gas line (4H).

Further, as a feature of the present invention, both the outdoor units (2) are used in both the cooling operation and the heating operation.
(A, 2B) is operating, the connection stop valve (V4) is open, and during the cooling operation, the high-pressure gas refrigerant flows almost equally through both outdoor heat exchangers (24), and during the heating operation, As a result, the low-pressure gas refrigerant flows almost evenly through both outdoor heat exchangers (24).

For example, during the cooling operation, when the operating capacity of the second outdoor unit (2B) becomes large with respect to the load, a part of the refrigerant discharged from the compressor (21) becomes part of the connection gas line (10).
Through the outdoor heat exchanger (2) in the first outdoor unit (2A).
4) will flow.

In the heating operation, if the operating capacity of the second outdoor unit (2B) becomes larger than the load, the first
Part of the refrigerant from the outdoor heat exchanger (24) in the outdoor unit (2A) passes through the connecting gas line (10), and the second outdoor unit (2
It will be sucked into the compressor (21) of B).

When the cooling operation of the second outdoor unit (2B) stops, the connection stop valve (V4) is fully closed, and as described above, the gas stop valve (V2) is in the open state.
The refrigerant of the second outdoor unit (2B) is sucked into the low pressure side of the first outdoor unit (2A).

When the heating operation of the second outdoor unit (2B) is stopped, the connection stop valve (V4) remains open, and the gas stop valve (V2) is fully closed as described above. The refrigerant of the second outdoor unit (2B) is connected to the connecting gas line (1
0) and is sucked into the low pressure side of the first outdoor unit (2A).

-Effect of Embodiment 5- According to the present embodiment, therefore, similarly to the first embodiment, the gas-side refrigerant pipe (26) of the outdoor heat exchanger (24) in the first outdoor unit (2A) is provided. ) And the gas-side refrigerant pipe (26) of the outdoor heat exchanger (24) in the second outdoor unit (2B), the refrigerant flowing through each outdoor heat exchanger (24) is substantially Since they can be equalized, the COP (coefficient of performance) can be improved.

Further, since the high pressure sensor for the cooling operation and the low pressure sensor for the heating operation in each outdoor unit (2A, 2B) can be shared, 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) is kept open, so that the refrigerant in the stopped second outdoor unit (2B) is reliably discharged. It can be collected in the first outdoor unit (2A).

Further, since two outdoor units (2A, 2B) are provided, it is not necessary to use a dedicated outdoor unit corresponding to the simultaneous cooling and heating operation system. Therefore, each outdoor unit (2A, 2B) Thus, various uses can be supported.

In particular, since only the liquid lines (5LA, 5LB) and the gas lines (5GA, 5GB) are extended from the outdoor units (2A, 2B), the so-called simultaneous cooling / heating operation is not performed. Since it can be used as a normal outdoor unit, various operations can be performed with a small number of models, and a highly versatile outdoor unit (2A, 2B) can be obtained.

In addition, outdoor units (2A, 2B) having different capacities
And the two outdoor units (2A, 2B) can be combined, so a small number of outdoor units (2A, 2B)
B) can handle a plurality of indoor units (3, 3,...), That is, various types of loads.

In addition, when the piping connection between the liquid lines (5LA, 5LB) and the main liquid line (4L) is formed in the piping unit (11), the piping inclination angle required for oil return and the like is determined. It is possible to surely keep a horizontal pipe at a place where a horizontal pipe is required. As a result, it is possible to reliably return the oil, prevent the liquid refrigerant from being flushed, and perform a 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, wherein the air conditioner (1) of embodiment 5 shown in FIG. , An auxiliary gas line (8a) is provided to adjust the operation capacity.

The auxiliary gas line (8a) has an auxiliary gas passage (82) continuously formed at the outer end of an auxiliary gas pipe (81) extending outside the first outdoor unit (2A). The inner end of (81) is the outdoor heat exchanger in the first outdoor unit (2A).
The refrigerant pipe (26) is connected between the (24) and the four-way switching valve (22). The auxiliary gas passage (82) is a high-pressure auxiliary passage.
(83) and a low-pressure auxiliary passage (84). The high-pressure auxiliary passage (83) is connected to the main high-pressure gas passage (42b), and is connected to the main high-pressure gas from the first outdoor unit (2A). A check valve (V25) that allows the refrigerant to flow toward the line (4H) is provided. On the other hand, the low-pressure auxiliary passage (84) is connected to the main low-pressure gas passage (43b), and is a check valve (4) that allows refrigerant to flow from the main low-pressure gas line (4W) to the first outdoor unit (2A). V26) is provided. The auxiliary gas line (8a) adjusts the cooling capacity and the heating capacity of both 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 branch connecting gas having a branch stop valve (V27). The passage (10c) is connected. One end of the branch connection gas passage (10c) is connected to the gas passage (57) in the gas line (5LA) on the first outdoor unit (2A) side, and the other end is connected to the connection gas line (10). Connection stop valve
The branch stop valve (V27) is connected to the second outdoor unit (2B) side from (V4), and constitutes a branch opening / closing mechanism that allows bidirectional refrigerant flow.

The branch connection gas passage (10c) and the second stop valve (V27) are integrated into the piping unit (11) to form a unit.

In this embodiment, the receiver (27) is provided in each of the outdoor units (2A, 2B) and the liquid stop valve (V1), as in the first embodiment shown in FIG. .

-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, FIG.
The operation is similar to that of the fifth embodiment shown in FIG. 7, and the auxiliary gas line (8a) does not participate in the operation.

Next, in the simultaneous cooling and heating operation, when the demand for the cooling capacity is large, the operation is as shown in FIG. For example, there is a case where one indoor unit (3) performs a heating operation and all other indoor units (3, 3,...) Perform a cooling 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 and
The outdoor unit (2A) and the second outdoor unit (2B) enter a cooling cycle state, and the compressor (2A) of both the outdoor units (2A, 2B)
The gas refrigerant discharged from 1) is supplied to the outdoor heat exchanger (24)
Then, the liquid refrigerant is condensed into a liquid refrigerant, and most of the liquid refrigerant joins the main liquid line (4L) and flows through the main liquid line (4L).

On the other hand, the compressor of the first outdoor unit (2A)
Part of the high-pressure gas refrigerant discharged from (21) flows into the auxiliary gas line (8a), flows from the high-pressure auxiliary passage (83) through the main high-pressure gas line (4H), and flows into the indoor unit (3) for heating operation. The high-pressure gas refrigerant condenses to become a liquid refrigerant. This liquid refrigerant is
In the flow divider (45) of the main liquid line (4L), the refrigerant merges with the liquid refrigerant from the outdoor units (2A, 2B), flows into the indoor unit (3, 3,. It becomes a gas refrigerant, returns to the compressor (21) of each outdoor unit (2A, 2B) through the main low-pressure gas line (4W), and repeats this circulation operation.

In the case of simultaneous heating and cooling operation, if the demand for the heating capacity is large, the operation is as shown in FIG. For example, one indoor unit (3) performs a cooling operation and all other indoor units (3, 3,...) Perform a 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, and the first outdoor unit (2A) and the second outdoor unit (2B) are heated. In the cycle state, the high-pressure gas refrigerant discharged from the compressors (21) of both outdoor units (2A, 2B) is supplied to the gas lines (5GA, 5G, respectively).
B) High pressure gas line through high pressure passage (57a, 58a)
(4H), and flow to the indoor unit (3, 3, ...) for heating operation.

The gas refrigerant is condensed into liquid refrigerant in the indoor units (3, 3,...), And flows into the main liquid line (4L). Thereafter, the liquid refrigerant is mostly passed through the main liquid line (4L) in the flow divider (45) of the main liquid line (4L), and passed through the outdoor heat exchanger (24) of each of the outdoor units (2A, 2B). To evaporate into low-pressure gas refrigerant.

On the other hand, in the indoor unit (3) for the cooling operation, a part of the liquid refrigerant is supplied to the flow divider of the main liquid line (4L).
It is split at (45), supplied through the branch liquid pipe (41c), and evaporated at the indoor unit (3) to become a low-pressure gas refrigerant. This low-pressure gas refrigerant passes through the main low-pressure gas line (4W),
The gas flows through the auxiliary gas line (8a) from the low-pressure auxiliary passage (84) and merges with the low-pressure gas refrigerant of the first outdoor unit (2A). Thereafter, each of the low-pressure gas refrigerants is supplied to each outdoor unit.
Returning to the compressor (21) of (2A, 2B), this circulation operation is repeated.

Further, in the simultaneous cooling / heating operation, when the demands for the cooling capacity and the heating capacity are both small and the demand for the cooling capacity is large, the state becomes as shown in FIG. 10. In this case, the second outdoor unit (2B) stops the operation.

On the other hand, in the first outdoor unit (2A), the four-way switching valve (22) switches to a solid line to enter a cooling cycle state, and discharges from the compressor (21) of the first outdoor unit (2A). The gas refrigerant is condensed in the outdoor heat exchanger (24) to become a liquid refrigerant, and flows through the main liquid line (4L).

Also, the compressor of the first outdoor unit (2A)
Part of the high-pressure gas refrigerant discharged from (21) flows into the auxiliary gas line (8a), flows from the high-pressure auxiliary passage (83) through the main high-pressure gas line (4H), and flows into the indoor unit (3) for heating operation. The high-pressure gas refrigerant condenses to become a liquid refrigerant. This liquid refrigerant is
At the flow divider (45) of the main liquid line (4L), the refrigerant merges with the liquid refrigerant from the first outdoor unit (2A), flows to the indoor unit (3, 3,. Becomes
Through the main low pressure gas line (4W), the first outdoor unit (2
Returning to the compressor (21) of A), this circulation operation is repeated.

Further, in the simultaneous cooling and heating operation, when both the demands for the cooling capacity and the heating capacity are small and the demand for the heating capacity is large, the result is as shown in FIG. 11, and in this case, as in FIG. Then, the operation of the second outdoor unit (2B) is stopped.

On the other hand, in the first outdoor unit (2A), the four-way switching valve (22) switches to a solid line to enter a heating cycle state, and the high-pressure gas discharged from the compressor (21) of the first outdoor unit (2A). Refrigerant flows through the main high-pressure gas line (4H) through the gas line (5GA), and the indoor unit (3, 3, 3,
…). And this indoor unit
At (3, 3,...), The liquid refrigerant is condensed to become a liquid refrigerant, and this liquid refrigerant flows to the main liquid line (4L). Thereafter, the liquid refrigerant is mostly passed through the main liquid line (4L) in the flow divider (45) of the main liquid line (4L), and the first outdoor unit (2A)
Evaporates into a low-pressure gas refrigerant in the outdoor heat exchanger (24).

In the indoor unit (3) for cooling operation, a part of the liquid refrigerant is supplied to the flow divider of the main liquid line (4L).
The liquid is split at (45), supplied through the branch liquid pipe (41c), and evaporated at the indoor unit (3) to become a low-pressure gas refrigerant. The 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 merges with the low-pressure gas refrigerant of the first outdoor unit (2A).
Thereafter, each of the low-pressure gas refrigerants is supplied to the first outdoor unit (2A).
And the circulation operation is repeated.

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) performs the cooling cycle. In this state, the second outdoor unit (2B) enters the heating cycle state or the reverse state, and executes the simultaneous cooling and heating operation.

When the operation of the second outdoor unit (2B) is stopped, the liquid stop valve (V1) is closed and the receiver (2B) is closed.
7) Prevents accumulation of liquid refrigerant in the apparatus. That is, since the liquid refrigerant pressure during operation is higher than the saturation pressure corresponding to the outside air temperature, the liquid refrigerant may accumulate in the receiver (27), and this accumulation is prevented.

Further, when the second outdoor unit (2B) stops, the gas passage (64) of the second outdoor unit (2B) is connected to the main low-pressure gas line (4W) via the refrigerant recovery passage (8b). As a result, the refrigerant in the second outdoor unit (2B) is recovered to the main low-pressure gas line (4W), and the accumulation of the liquid refrigerant in the second outdoor unit (2B) is prevented.

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

[0204]

[Table 1]

More specifically, for example, all the indoor units (3,
(3,...) Perform the cooling operation and both the first outdoor unit (2A) and the second outdoor unit (2B) are in the cooling cycle state (Table 1).
-), The high pressure reversing valve (V28) and the low pressure reversing valve (V29) are closed, the connection stop valve (V4) is open, the branch stop valve (V27) is closed, and both outdoor units (2A, 2B) are closed. ), The high-pressure refrigerant pressure on the discharge side of the compressor (21) and the low-pressure refrigerant pressure on the suction side are equal.

Further, all the indoor units (3, 3,...) Perform the heating operation to perform the first outdoor unit (2A) and the second outdoor unit (2B).
Are both in the heating cycle state (see Table 1), the high pressure reversing valve (V28) and the low pressure reversing valve (V29) are closed,
The connection stop valve (V4) opens, the branch stop valve (V27) is closed, and the compressor (21) in both outdoor units (2A, 2B)
, The high-pressure refrigerant pressure on the discharge side becomes equal to the low-pressure refrigerant pressure on the suction side.

Further, during the simultaneous cooling / heating operation in which the indoor units (3, 3,...) Perform the heating operation and the cooling operation, the first outdoor unit (2A) enters the cooling cycle state, and the second outdoor unit (2B) operates. 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 discharge side of the compressor (21) in both outdoor units (2A, 2B). Are equal in pressure. 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 outdoor units (2A, 2B) becomes equal.

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

Further, 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), the connection stop valve (V4) is opened as described above, so that in the cooling cycle state, the high-pressure gas refrigerant In the heating cycle state, the low-pressure gas refrigerant flows in the both outdoor heat exchangers (24) almost evenly in the both outdoor heat exchangers (24).

For example, in the cooling cycle state,
When the operating capacity of the second outdoor unit (2B) increases with respect to the load, a part of the refrigerant discharged from the compressor (21) passes through the connecting gas line (10) and the outdoor heat in the first outdoor unit (2A). It will flow to the exchanger (24).

In the heating cycle state, when the operating capacity of the second outdoor unit (2B) becomes larger than the load, a part of the refrigerant sucked into the compressor (21) of the first outdoor unit (2A) is removed. It flows to the second outdoor unit (2B) through the connecting gas line (10).

-Effect of Embodiment 6- Therefore, according to the present embodiment, the connection gas line (10) and the branch connection gas passage (10c) are provided.
The outdoor unit (2A) is provided with a high-pressure pressure sensor (HPS) and a low-pressure pressure sensor (LPS), while the second outdoor unit (2B) is provided with an indoor unit (3, 3,...) From a four-way switching valve (22). ), The refrigerant pressure of the second outdoor unit (2B) can be detected only by providing one common pressure sensor (CSP) in the gas pipe (62).

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 equal to the high pressure sensor (HPS) of the first outdoor unit (2A). It can be detected by a pressure sensor (LPS). As a result, it is only necessary to provide the common pressure sensor (CSP) in the second outdoor unit (2B), the number of parts can be reduced, and the refrigerant flowing through each outdoor heat exchanger (24) is made almost uniform. Therefore, the COP (coefficient of performance) can be improved.

In addition to the provision of the auxiliary gas line (8a), in addition to the case where the requirements for the cooling capacity and the heating capacity are balanced, the case where the demand for the cooling capacity is large, Simultaneous cooling and heating operation can be performed when the demand is large and the cooling and heating capacity requirements are both small. As a result, since the operation range can be expanded, it is possible to cope with various use states.

Further, by providing the auxiliary gas line (8a), only the compressor (21) of the first outdoor unit (2A) is subjected to inverter control to perform linear control corresponding to the load, and the second outdoor unit (8a) is controlled. Since the compressor (21) of 2B) has three stages of unload control and the operating range can be expanded as described above, various modes can be dealt with with simple control.

Other functions and effects are the same as those of the fourth embodiment shown in FIGS.

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.
Reversible valves (V28, V29) are provided in place of (V25, V26) to share the sensor.

That is, the high-pressure auxiliary passage (83) in the auxiliary gas line (8a) is provided with a high-pressure auxiliary passage allowing bidirectional refrigerant flow between the first outdoor unit (2A) and the main high-pressure gas line (4H). A reversible valve (V28) is provided, and the first outdoor unit (2A) and the main low-pressure gas line are provided in the low-pressure auxiliary passage (84).
(4W) low-pressure reversible valve (V
29) is provided. The high-pressure reversible valve (V28) and the low-pressure reversible valve (V29) are provided integrally with the piping unit (11).

In the first outdoor unit (2A), a refrigerant pipe (26) on the discharge side of the compressor (21) is provided with a high pressure sensor (HPS) for detecting the pressure of the discharged refrigerant. Two
The refrigerant pipe (26) on the suction side of 1) is provided with a low-pressure pressure sensor (LPS) for detecting the suction refrigerant pressure. In the second outdoor unit (2B), both pressure sensors are omitted.

In addition, the configuration of the connection gas line (10)
This is the same as 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, all the indoor units (3, 3,...) Perform the cooling operation to perform the first outdoor unit (2A) and the second outdoor unit (2B).
Is in the cooling cycle state, the double reversing valve (V2
8, V29) are both closed.

Further, as shown in FIG. 12, the simultaneous cooling and heating operation is performed, the four-way switching valve (22) of the first outdoor unit (2A) is switched to a solid line, and the first outdoor unit (2A) is heated. When the four-way switching valve (22) of the second outdoor unit (2B) is switched to a solid line and the second outdoor unit (2B) is in the cooling cycle state, the high-pressure reversible valve (V28) is closed. Then, 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 (2B ) Low pressure refrigerant pressure (LP) of the first outdoor unit (2A)
S).

Therefore, since the low-pressure refrigerant pressure is common, the excess or deficiency of the cooling capacity is determined by the compressor (2A) in the first outdoor unit (2A).
It can be controlled by a combination of the capacity of 1) and the capacity of the compressor (21) in the second outdoor unit (2B). Also, the capacity of the compressor (21) and the outdoor electric expansion valve are controlled so that the low-pressure refrigerant pressure does not become abnormally low due to the drift of the liquid refrigerant or the like.
The opening of (25) will be controlled.

On the other hand, all the indoor units (3, 3,...) Perform the heating operation, and the first outdoor unit (2A) and the second outdoor unit (2B)
Is in the heating cycle state, the two-way reversing valve (V2
8, V29) are both closed.

Further, as shown in FIG. 13, the simultaneous cooling and heating operation is performed, the four-way switching valve (22) of the first outdoor unit (2A) is switched to a solid line, and the first outdoor unit (2A) is operated in the cooling cycle. When the four-way switching valve (22) of the second outdoor unit (2B) is switched to a solid line and the second outdoor unit (2B) is in a heating cycle state, the high-pressure reversible valve (V28) is opened. Then, the low pressure reversible valve (V29) is closed. As a result, in any of the above cases, the high-pressure refrigerant pressure of the second outdoor unit (2B) becomes equal to the high-pressure refrigerant pressure of the first outdoor unit (2A), and the second outdoor unit (2B ) High pressure refrigerant pressure (HP) of the first outdoor unit (2A)
S).

Therefore, since the high-pressure refrigerant pressure is common, the excess or deficiency of the heating capacity is determined by the compressor (2) in the first outdoor unit (2A).
It can be controlled by a combination of the capacity of 1) and the capacity of the compressor (21) in the second outdoor unit (2B). Then, the capacity of the compressor (21) and the opening of the outdoor electric expansion valve (25) are controlled so that the high-pressure refrigerant pressure does not become abnormally high.

The other operations in this embodiment are described in FIGS.
This is the same as the sixth embodiment shown in FIG. 11, and in the operation states of FIGS. 8 and 10, the low-pressure reversible valve (V29) is closed and the high-pressure reversible valve (V28) is opened. 9 and 11, the low pressure reversible valve (V29) is opened and the high pressure reversible valve (V2
8) Close. Further, it goes without saying that the operation shown in FIGS. 6 and 7 can be performed.

-Effect of Embodiment 7- Accordingly, according to the present embodiment, the high-pressure pressure sensor (HPS)
By providing the low pressure pressure sensor (LPS) only in the first outdoor unit (2A), the sensor of the second outdoor unit (2B) can be omitted, and the number of parts can be reduced without lowering the control accuracy. Can be reduced.

In addition, the operating capacity can be adjusted in the same manner as in the embodiment shown in FIGS. 8 to 11, and the check valve (V2
5, V26) can be shared by merely replacing the reversible valves (V28, V29), so that the operating range can be expanded and the number of sensors can be reduced.

Other effects are the same as 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 and is not limited to the sixth embodiment shown in FIGS.
In the embodiment, a pressure equalizing passage (8c) is provided to enable equalization of the main high-pressure gas line (4H) and the main low-pressure gas line (4W).

That is, the equalizing passage (8c) is provided between the main high-pressure gas passage (42b) of the main high-pressure gas line (4H) and the main low-pressure gas passage (43b) of the main low-pressure gas line (4W). And a pressure equalizing valve (V30) is provided. The pressure equalizing valve (V30) constitutes a pressure equalizing opening / closing mechanism for flowing and blocking 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 (84) are connected to the first outdoor unit by the auxiliary gas passage (82).
An auxiliary reversible valve (V31) is provided on the (2A) side, and the auxiliary reversible valve (V3
1) constitutes an auxiliary opening / closing mechanism that is closed when equalizing the pressure of the main low-pressure gas line (4W) to the main high-pressure gas line (4H).

The pressure equalizing passage (8c) and the pressure equalizing valve (V30)
The auxiliary reversible valve (V31) is provided integrally with the piping unit (11).

In addition, the configuration of the connecting gas line (10)
This is the same as the sixth embodiment shown in FIGS.

-Operation and Effect of Eighth Embodiment- Next, a pressure equalizing operation of the eighth embodiment will be described.

This equalizing operation is performed in the indoor unit (3, 3,...).
For example, when switching from the cooling operation to the heating operation in one indoor unit (3), the low-pressure valve (72) is closed and the high-pressure valve (71) is opened.

When equalizing the main low-pressure gas line (4W) to the main high-pressure gas line (4H), as shown in FIG. 14, the four-way switching valve (22) of the first outdoor unit (2A) is changed to a solid line. The first outdoor unit (2A) is switched to the heating cycle state. 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 compressor of the first outdoor unit (2A)
The high-pressure gas refrigerant discharged from (21) passes through the main high-pressure gas line (4H) from the gas line (5GB), flows into the main low-pressure gas line (4W) from the equalizing passage (8c), and The line (4W) is equalized to high pressure.

On the contrary, the main high-pressure gas line (4H)
When the pressure is equalized to the main low-pressure gas line (4W), the operation of both outdoor units (2A, 2B) is stopped and the equalizing valve (V30) is opened as shown in FIG. In this state, the high-pressure gas refrigerant in the main high-pressure gas line (4H) flows into 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
(8c), the main high-pressure gas line is switched when the indoor unit (3) switches between the cooling and heating operations.
(4H) and the main low-pressure gas line (4W) can be equalized, so that generation of vibration and noise due to switching can be reliably prevented.

Other functions and effects are the same as those of the sixth embodiment shown in FIGS.

The pressure equalizing passage (8c) of this embodiment may be provided in the seventh embodiment shown in FIGS. 12 and 13. In this case, it is not necessary to provide the auxiliary reversible valve (V31).

Embodiment 9 FIG. 16 shows another embodiment, in which the second outdoor unit (2
B1), a third outdoor unit (2B2) is provided in addition to the second outdoor unit (2B1) and the third outdoor unit (2B2).
2) has the same configuration as the second outdoor unit (2B) in FIG. 6 and FIG.

That is, the second outdoor unit (2B1)
For the first outdoor unit (2A), a connection gas line (10) having a connection stop valve (V4a) and a branch stop valve are provided similarly to the connection gas line (10) and the branch connection passage (10c) shown in FIG. (V27a) are connected via a branch connection passage (10c). Similarly, the third outdoor unit (2B2)
Connection stop valve (V4b) for the first outdoor unit (2A)
Connecting gas line (101) having a branch stop valve (V27b)
Are connected via a branch connection passage (10c1) having

Each of the connection stop valves (V4a, V4b)
And the respective branch stop valves (V27a, V27b) correspond to FIGS.
The operation is performed as shown in Table 2 below, similarly to the sixth embodiment.

[0247]

[Table 2]

More specifically, for example, the indoor unit (3, 3,
…) During the simultaneous cooling / heating operation in which the heating operation and the cooling operation are performed (see Table 2- (6)), the first outdoor unit (2A) enters the cooling cycle state, and the second outdoor unit (2B1) enters the heating cycle state. Becomes Then, the third outdoor unit (2B2) enters a cooling cycle state, a heating cycle state or a stop state in accordance with the fluctuation of the cooling capacity and the heating capacity, and in this cooling cycle state, the connection stop valve (V4b) is opened. , The branch stop valve (V27b) is closed, and in the heating cycle state, the connection stop valve (V4b) is closed and the branch stop valve
(V27b) is open and in the stopped state, the connection stop valve (V4b)
Is closed, and the branch stop valve (V27b) is opened. As a result, in each of the outdoor units (2A, 2B1, 2B2), the high-pressure refrigerant pressure on the discharge side and the low-pressure refrigerant pressure on the suction side of the compressor (21) become equal.

Other structures, functions and effects are shown in FIGS.
The sixth embodiment is similar to the sixth embodiment of FIG. 11, but is provided with reversible valves (V28, V29) shown in FIGS. 12 and 13 instead of the check valves (V25, V26).

-Other Embodiments- In each of the embodiments described above, an air conditioner capable of reversible operation in a cooling / heating cycle has been described. However, as an invention of claim 1, an air conditioner dedicated to cooling may be used. . In 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. Unit (2B)
When the cooling operation is stopped, the liquid stop valve (V1) is fully closed.

In the first to fourth embodiments, three or more outdoor units (2) may be provided.

Further, the branch connection gas passage (10
c) may be provided in the fifth embodiment shown in FIGS.

The pressure equalizing passage (8c) of the eighth embodiment is the same as that of FIG.
And the fifth embodiment shown in FIG.

[Brief description of the 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 a main part 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 modification of the gas stop valve.

FIG. 5 is a main part refrigerant circuit diagram showing a fourth embodiment of the present invention.

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

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

FIG. 8 is a main part refrigerant circuit diagram showing a sixth embodiment of the present invention.

FIG. 9 is a refrigerant circuit diagram of a main part showing an operation state of a sixth embodiment.

FIG. 10 is a refrigerant circuit diagram of a main part showing an operation state of a sixth embodiment.

FIG. 11 is a refrigerant circuit diagram of a main part showing an operation state of a sixth embodiment.

FIG. 12 is a main part refrigerant circuit diagram showing a seventh embodiment of the present invention.

FIG. 13 is a refrigerant circuit diagram of a main part showing an operation state of the seventh embodiment.

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

FIG. 15 is a refrigerant circuit diagram of a main part showing an operation state of the eighth embodiment.

FIG. 16 is a main part refrigerant circuit diagram 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 Equalizing passage 10 Connecting gas line 10c Branch connecting gas passage 12 Receiver V1 Liquid stop valve (liquid opening and closing mechanism) V2 Gas stop valve (gas opening and closing mechanism) V4 Connection stop valve (connection opening and closing mechanism) V27 Branch Stop valve (branch opening / closing mechanism) V30 Equalizing valve (equalizing opening / closing mechanism)

Claims (8)

(57) [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 gas lines (5GA, 5GB) connected to the suction side of the compressor (21), and the respective heat source units (2A, 2B) connected in parallel. The main liquid line (4L) and the main gas line (4G) to which the outer ends of each liquid line (5LA, 5LB) and each gas line (5GA, 5GB) are connected, respectively, and the use side expansion mechanism (33) And a plurality of use units (3A, 3B) connected in parallel to the main liquid line (4L) and the main gas line (4G). A liquid opening / closing mechanism (V1) that 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), respectively Re is connected to the gas side refrigerant pipe of the heat source-side heat exchanger (24) (26) in the refrigerant flow during the cooling operation at least all the heat source units (2A, 2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) for allowing and stopping the refrigerant flow to the stopped heat source unit (2B) when the cooling operation of the one heat source unit (2B) is stopped. A refrigeration apparatus characterized by the above-mentioned. 2. A compressor (21), one end of which is switchably connected to a discharge side and a suction side of the compressor (21), and the other end of which is a liquid line.
(5LA, 5LB), a heat source side heat exchanger (24) connected to the liquid line (5LA, 5LB), and a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB). Gas lines on the discharge side and the suction side
(5GA, 5GB) switchably connected to the first heat source unit (2
A) and the second heat source unit (2B), and the outer ends of each liquid line (5LA, 5LB) and each gas line (5GA, 5GB) so that each heat source unit (2A, 2B) is connected in parallel. It has a main liquid line (4L) and a main gas line (4G) connected to each other, and a use side heat exchanger (32), and is in parallel with the main liquid line (4L) and the main gas line (4G). A plurality of connected use 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 (5B) is stopped.
LB) and a liquid opening / closing means (V1) for closing the second heat source unit (2B). The gas switching 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), respectively, and at least the total heat source unit (2A, 2B) Refrigerant circulation during cooling operation
A connection gas line (10) having a connection opening / closing mechanism (V4) for allowing and stopping the refrigerant flow to the stopped heat source unit (2B) when the cooling operation of the one heat source unit (2B) is stopped. A refrigeration apparatus characterized by the above-mentioned. 3. A compressor (21), one end of which is switchably connected to a discharge side and a suction side of the compressor (21), and the other end of which is a liquid line.
(5LA, 5LB), a heat source side heat exchanger (24) connected to the liquid line (5LA, 5LB), and a heat source side expansion mechanism (25) provided in the liquid line (5LA, 5LB). Gas lines on the discharge side and the suction side
(5GA, 5GB) switchably connected to the first heat source unit (2
A) and a second heat source unit (2B); a main liquid line (4L) to which the outer ends of the liquid lines (5LA, 5LB) of the heat source units (2A, 2B) are connected; It has a main gas line (4G) to which the outer end side of the gas line (5GA) of the unit (2A) is connected, and a use side heat exchanger (32), and the main liquid line (4L) and the main gas line (4G) ), A plurality of utilization units (3A, 3B) connected in parallel with each other, and a heat source side heat exchanger (24) in the first heat source unit (2A).
Branch line (5) with one end connected to the gas side refrigerant pipe (26)
a), the main gas line (4G) and the branch line (5a) are connected, and a constantly high-pressure passage (91) constantly maintained at a high pressure state and a constantly low-pressure passage (92) constantly maintained at a low pressure state Have, second
A gas line (5 GB) on the side of the heat source unit (2B) is connected to the always high pressure passage (91) so that refrigerant can flow from the gas line (5GB) toward the always high pressure passage (91). 2 Gas line (5GB) on heat source unit (2B) side is always low pressure passage
A constant pressure circuit (9) connected to the low-pressure passage (92) so that the refrigerant can flow from (92) toward the gas line (5GB); and a liquid line (5LB) on the second heat source unit (2B) side Liquid line (5) when the operation of the second heat source unit (2B) is stopped.
A liquid opening and closing means for closing the LB) (25), both ends are connected to the gas side refrigerant pipe (26) of the heat source units (2A, 2B) the heat source side heat exchanger in (24), at least all the heat source unit ( 2A, 2B)
A connection gas line (10) having a connection opening / closing mechanism (V4) for allowing and stopping the refrigerant flow to the stopped heat source unit (2B) when the cooling operation of the one heat source unit (2B) is stopped. A refrigeration apparatus characterized by the above-mentioned. 4. A compressor (21), one end of which is switchably connected to a discharge side and a suction side of the compressor (21), and the other end of which is a liquid line.
(5LA, 5LB) connected to the heat source side heat exchanger (24), and the liquid line (5LA, 5LB) provided with a heat source side expansion mechanism (25), from the compressor (21) The gas lines (5GA, 5GB) are branched into a high-pressure passage (57a, 58a) allowing the refrigerant flow in the discharge direction and a low-pressure passage (57b, 58b) allowing the refrigerant flow in the suction direction of the compressor (21). A plurality of heat source units (2) whose base ends are switchably connected to the discharge side and the suction side of the compressor (21).
A, 2B) and each liquid line (5LA, 5LB), each high-pressure passage (57a, 58a) and each low-pressure passage (57b, 58b) so that each heat source unit (2A, 2B) is connected in parallel. Main liquid lines (4
L), a main high-pressure gas line (4H) and a main low-pressure gas line (4W), a use-side heat exchanger (32) having one end connected to the main liquid line (4L), and a use-side heat exchanger ( 32) and main liquid line (4
L) and the other end of the use side heat exchanger (32) is connected to the main high-pressure gas line (4H) and the main low-pressure gas line (4W). And a plurality of use units (3, 3, ...) switchably connected to a gas source refrigerant pipe (26) of a heat source side heat exchanger (24) in one heat source unit (2A). The gas-side refrigerant pipe (26) of the heat source-side heat exchanger (24) in the heat source unit (2B) is provided so as to communicate with at least the total heat source units (2A, 2A).
A refrigeration apparatus comprising: a connection gas line (10) having a connection opening / closing mechanism (V4) that allows bidirectional refrigerant flow during the cooling operation and the heating operation in B) . 5. A compressor (21), one end of which is switchably connected to a discharge side and a suction side of the compressor (21), and the other end of which is a liquid line.
(5LA, 5LB) connected to the heat source side heat exchanger (24), and the liquid line (5LA, 5LB) provided with a heat source side expansion mechanism (25), from the compressor (21) The gas lines (5GA, 5GB) are branched into a high-pressure passage (57a, 58a) allowing the refrigerant flow in the discharge direction and a low-pressure passage (57b, 58b) allowing the refrigerant flow in the suction direction of the compressor (21). A plurality of heat source units (2) whose base ends are switchably connected to the discharge side and the suction side of the compressor (21).
A, 2B) and each liquid line (5LA, 5LB), each high-pressure passage (57a, 58a) and each low-pressure passage (57b, 58b) so that each heat source unit (2A, 2B) is connected in parallel. Main liquid lines (4
L), a main high-pressure gas line (4H) and a main low-pressure gas line (4W), a use-side heat exchanger (32) having one end connected to the main liquid line (4L), and a use-side heat exchanger ( 32) and main liquid line (4
L) and the other end of the use side heat exchanger (32) is connected to the main high-pressure gas line (4H) and the main low-pressure gas line (4W). And a plurality of use units (3, 3, ...) switchably connected to each other, and a heat source side heat exchanger in one heat source unit (2A) at 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), and the heat source unit (2A) and the main high-pressure gas line ( 4H) and a low-pressure auxiliary passage (84) that allows refrigerant flow between the main low-pressure gas line (4W) and the heat source unit (2A). A gas line (8a) and a heat source side heat exchanger (24) in another heat source unit (2B) with respect to a gas side refrigerant pipe (26) of a heat source side heat exchanger (24) in one heat source unit (2A) Gas-side refrigerant pipe (26) is provided so as to communicate with at least the total heat source units (2A, 2A).
A refrigeration apparatus comprising: a connection gas line (10) having a connection opening / closing mechanism (V4) that allows bidirectional refrigerant flow during the cooling operation and the heating operation in B) . 6. The refrigeration system according to claim 4, wherein one end of the gas line (5A) in one heat source unit (2A) is provided.
A), and a branch opening and closing mechanism (the other end of which is connected between the other heat source unit (2B) and the connection opening and closing mechanism (V4) in the connection gas line (10) to allow bidirectional refrigerant flow. A refrigeration apparatus comprising a branch connection gas passage (10c) having V27). 7. The refrigeration apparatus 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 flowing and blocking refrigerant from the main high-pressure gas line (4H) to the main low-pressure gas line (4W). A refrigeration apparatus characterized by the following. 8. The refrigeration apparatus according to claim 1, wherein a receiver (12) connecting each of the liquid lines (5LA, 5LB) and the main liquid line (4L) is connected to each of the liquid lines (5LA). , 5LB) and the main liquid line (4L).