JP6543898B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly to a remote condenser type air conditioner configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger.

  BACKGROUND Conventionally, there is a remote condenser type air conditioner configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger. As shown in Patent Document 1 (Japanese Patent Application Laid-Open No. 58-75676) as such a remote condenser type air conditioner, a plurality of indoor units (utilization units) having a compressor and an evaporator (indoor heat exchanger) There is a remote condenser type air conditioner connected to an outdoor unit having a condenser (outdoor heat exchanger) having a configuration divided into a plurality of independent refrigerant systems.

  In the configuration of the remote condenser type of Patent Document 1, the outdoor heat exchanger has a configuration divided into independent refrigerant systems so as to correspond to each usage unit. Therefore, cooling can be performed according to the cooling load (heat load) in each usage unit. Further, in this configuration, by providing a four-way switching valve or the like in each usage unit to make it possible to switch the flow direction of the refrigerant in each refrigerant system, it is possible to switch between cooling and heating in each usage unit. Is considered.

  However, in the configuration of the remote condenser type of Patent Document 1, even if cooling and heating can be switched in each use unit, as described above, the outdoor heat exchanger may correspond to each use unit. Since it has a configuration divided into independent refrigerant systems, when performing an operation in which a usage unit for cooling and a usage unit for heating are mixed (cooling and heating mixed operation), the usage unit for cooling and heating are used. Exhaust heat recovery can not be performed with the utilization unit.

  An object of the present invention is to provide a remote condenser type air conditioner configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger, and performing cooling and heating while performing exhaust heat recovery. It is to be able to perform mixed operation.

The air conditioning apparatus according to the first aspect includes a plurality of usage units, an outdoor unit, a liquid refrigerant communication pipe, a gas refrigerant communication pipe, and a control unit . The utilization unit includes a compressor, an indoor heat exchanger, and a utilization side switching mechanism that switches between a state in which the indoor heat exchanger functions as a radiator of refrigerant and a state in which the indoor heat exchanger functions as a refrigerant evaporator. . The outdoor unit does not have a compressor, and has an outdoor heat exchanger common to a plurality of usage units. The liquid refrigerant communication pipe is branched from the liquid refrigerant communication junction pipe connected to the outdoor unit so as to be in communication with the liquid side of the outdoor heat exchanger and the liquid refrigerant communication junction pipe and is communicated with the liquid side of each indoor heat exchanger And a plurality of liquid refrigerant communication branch pipes connected to each usage unit. The gas refrigerant communication pipe is branched from the gas refrigerant communication junction pipe connected to the outdoor unit so as to be in communication with the gas side of the outdoor heat exchanger and the gas refrigerant communication junction pipe so as to be in communication with each use side switching mechanism And a plurality of gas refrigerant communication branch pipes connected to each usage unit. The control unit controls the devices constituting the outdoor unit and the plurality of usage units so that an operation in which the indoor heat exchanger functioning as a refrigerant radiator and the indoor heat exchanger functioning as a refrigerant evaporator are mixed is performed. It is possible.

  Here, in the remote condenser type air conditioner configured by connecting the utilization unit having the compressor and the indoor heat exchanger to the outdoor unit having the outdoor heat exchanger, first, the utilization-side switching mechanism for each utilization unit Is provided so that cooling and heating can be switched and performed in each usage unit. Moreover, the outdoor heat exchanger is shared by a plurality of usage units, and the liquid side of the outdoor heat exchanger is branched to communicate with the liquid side of each indoor heat exchanger in the liquid refrigerant communication pipe and connected to each usage unit The outdoor heat exchanger is a refrigerant system common to a plurality of utilization units by branching the gas side of the outdoor heat exchanger in the gas refrigerant communication pipe so as to communicate with each utilization side switching mechanism and connecting it to each utilization unit I am trying to For this reason, here, when performing an operation (cooling and heating mixed operation) in which the usage unit performing cooling and the usage unit performing heating coexist, the refrigerant communication pipe between the usage unit performing cooling and the usage unit performing heating The outdoor heat exchanger can be made to function as a radiator or evaporator of the refrigerant according to the difference between the cooling load in the utilization unit for cooling and the heating load in the utilization unit for heating while exchanging the refrigerant through. In addition, since the compressor is provided in each usage unit, detailed operation control can be performed for each usage unit. For example, for a usage unit that performs heating, the target value of the discharge pressure (high pressure of the refrigeration cycle) of the compressor is set for each usage unit, and for the usage unit that performs cooling, the suction pressure of the compressor (for each usage unit The target value of the low pressure of the refrigeration cycle can be set, and the operating capacity of the compressor can be controlled to obtain such a target value.

  Thereby, here, in the remote condenser type air conditioner configured by connecting the utilization unit having the compressor and the indoor heat exchanger to the outdoor unit having the outdoor heat exchanger, cooling and heating while performing exhaust heat recovery Mixed operation can be performed.

  An air conditioning apparatus according to a second aspect of the present invention is the air conditioning apparatus according to the first aspect, wherein each usage unit includes a compressor unit including a compressor, and an indoor unit including an indoor heat exchanger. There is.

  Here, each utilization unit is configured by a compressor unit including a compressor and an indoor unit including an indoor heat exchanger. Therefore, the indoor unit can be disposed in and near the room, and the compressor unit including the compressor can be disposed at a location away from the room. Also, a plurality of indoor units can be connected to a common compressor unit for each group.

  Thereby, the noise and vibration by a compressor can be suppressed in a living room here. In addition, the number of compressor units can be reduced.

  The air conditioning apparatus according to a third aspect is the air conditioning apparatus according to the first or second aspect, wherein each utilization unit bypasses the compressor so that the refrigerant is drawn from the suction side of the compressor to the discharge side of the compressor It has a compressor bypass pipe that can be sent.

  Here, since the compressor bypass pipe is provided, it is possible to set, for each usage unit, whether to compress the refrigerant or to bypass the refrigerant without compressing the refrigerant. For this reason, in this case, it is possible to set, according to need, one that performs compression of the refrigerant and one that does not perform compression of the refrigerant among the use units that perform cooling and heating.

  As a result, in this case, it is possible to perform an operation in which the utilization unit for compressing the refrigerant by the compressor and the utilization unit for bypassing without compressing the refrigerant by the compressor coexist.

The air conditioning apparatus according to the fourth aspect has a plurality of usage units, an outdoor unit, a liquid refrigerant communication pipe, and a gas refrigerant communication pipe. The utilization unit includes a compressor, an indoor heat exchanger, and a utilization side switching mechanism that switches between a state in which the indoor heat exchanger functions as a radiator of refrigerant and a state in which the indoor heat exchanger functions as a refrigerant evaporator. . An outdoor unit has an outdoor heat exchanger common to a plurality of utilization units. The liquid refrigerant communication pipe is branched from the liquid refrigerant communication junction pipe connected to the outdoor unit so as to be in communication with the liquid side of the outdoor heat exchanger and the liquid refrigerant communication junction pipe and is communicated with the liquid side of each indoor heat exchanger And a plurality of liquid refrigerant communication branch pipes connected to each usage unit. The gas refrigerant communication pipe is branched from the gas refrigerant communication junction pipe connected to the outdoor unit so as to be in communication with the gas side of the outdoor heat exchanger and the gas refrigerant communication junction pipe so as to be in communication with each use side switching mechanism And a plurality of gas refrigerant communication branch pipes connected to each usage unit.

Here, in the remote condenser type air conditioner configured by connecting the utilization unit having the compressor and the indoor heat exchanger to the outdoor unit having the outdoor heat exchanger, first, the utilization-side switching mechanism for each utilization unit Is provided so that cooling and heating can be switched and performed in each usage unit. Moreover, the outdoor heat exchanger is shared by a plurality of usage units, and the liquid side of the outdoor heat exchanger is branched to communicate with the liquid side of each indoor heat exchanger in the liquid refrigerant communication pipe and connected to each usage unit The outdoor heat exchanger is a refrigerant system common to a plurality of utilization units by branching the gas side of the outdoor heat exchanger in the gas refrigerant communication pipe so as to communicate with each utilization side switching mechanism and connecting it to each utilization unit I am trying to For this reason, here, when performing an operation (cooling and heating mixed operation) in which the usage unit performing cooling and the usage unit performing heating coexist, the refrigerant communication pipe between the usage unit performing cooling and the usage unit performing heating The outdoor heat exchanger can be made to function as a radiator or evaporator of the refrigerant according to the difference between the cooling load in the utilization unit for cooling and the heating load in the utilization unit for heating while exchanging the refrigerant through. In addition, since the compressor is provided in each usage unit, detailed operation control can be performed for each usage unit. For example, for a usage unit that performs heating, the target value of the discharge pressure (high pressure of the refrigeration cycle) of the compressor is set for each usage unit, and for the usage unit that performs cooling, the suction pressure of the compressor (for each usage unit The target value of the low pressure of the refrigeration cycle can be set, and the operating capacity of the compressor can be controlled to obtain such a target value.

Thereby, here, in the remote condenser type air conditioner configured by connecting the utilization unit having the compressor and the indoor heat exchanger to the outdoor unit having the outdoor heat exchanger, cooling and heating while performing exhaust heat recovery Mixed operation can be performed.

Also, each utilization unit here has a compressor bypass pipe capable of bypassing the compressor and sending the refrigerant from the suction side of the compressor to the discharge side of the compressor.

Here, since the compressor bypass pipe is provided, it is possible to set, for each usage unit, whether to compress the refrigerant or to bypass the refrigerant without compressing the refrigerant. For this reason, in this case, it is possible to set, according to need, one that performs compression of the refrigerant and one that does not perform compression of the refrigerant among the use units that perform cooling and heating.

As a result, in this case, it is possible to perform an operation in which the utilization unit for compressing the refrigerant by the compressor and the utilization unit for bypassing without compressing the refrigerant by the compressor coexist.

Furthermore, the control unit which controls the apparatus which comprises an outdoor unit and several utilization units is further provided here . The control unit has an operation mode in which an indoor heat exchanger functioning as a refrigerant radiator and an indoor heat exchanger functioning as a refrigerant evaporator are mixed. In this operation mode, the compressor bypass condition is In the case of filling, either the compressor of the utilization unit corresponding to the indoor heat exchanger functioning as a radiator of the refrigerant, or the compressor of the utilization unit corresponding to the indoor heat exchanger functioning as an evaporator of the refrigerant The compressor bypass control is performed to bypass the compressor stopped via the compressor bypass pipe and send the refrigerant from the suction side of the compressor stopped to the discharge side of the stopped compressor.

  Here, there is an operation mode in which an indoor heat exchanger functioning as a refrigerant radiator and an indoor heat exchanger functioning as a refrigerant evaporator coexist, that is, a usage unit performing cooling and a usage unit performing heating are mixed. There is a combined heating and cooling operation mode. In such an operation mode, since the refrigerant is exchanged between the utilization unit performing cooling and the utilization unit performing heating via the refrigerant communication pipe, the refrigeration cycle resulting from the outside air temperature, the cooling load, and the size of the heating load Depending on the conditions of high and low pressure, in a specific usage unit, cooling and heating may be performed without compression of the refrigerant in the compressor of the usage unit itself.

  For example, in combined cooling and heating combined operation where the cooling load of the entire plurality of usage units is larger than the heating load and the outdoor heat exchanger functions as a radiator of refrigerant, the outdoor temperature is high, and the outdoor heat exchange is performed. Under the condition that the pressure difference between the high pressure in the heat exchanger and the high pressure in the indoor heat exchanger for heating becomes small, the high pressure sent from the utilization unit for cooling without compression of the refrigerant by the compressor of the utilization unit for heating Heating can be performed with the In addition, in mixed heating / cooling combined operation in which the heating load of the entire plurality of usage units is larger than the cooling load and the outdoor heat exchanger functions as an evaporator of the refrigerant, the outdoor temperature is low, and the outdoor heat exchange is performed. On the condition that the pressure difference between the low pressure in the cooling unit and the low pressure in the indoor heat exchanger for cooling becomes small, the high pressure refrigerant in the utilization unit for heating without compression of the refrigerant by the compressor of the utilization unit for cooling Heating can be performed. Furthermore, in a mixed heating / cooling operation in which cooling load and heating load of the entire plurality of usage units are balanced, cooling is performed under the condition that the cooling load and the heating load are small and the difference between high and low pressure of the refrigeration cycle is small. Even if compression of the refrigerant is performed by either the compressor of the utilization unit or the compressor of the utilization unit performing heating, and compression of the refrigerant is not performed by the compressors of other utilization units, cooling and heating are performed in all utilization units. It can be carried out.

  Therefore, in this case, a condition that can perform cooling and heating without compression of the refrigerant in the specific usage unit as described above is set as the compressor bypass condition, and the compressor bypass in the cooling and heating mixed operation mode is set. When the condition is satisfied, the compressor bypass control provided in each utilization unit is used to perform the compressor bypass control.

  Thus, here, in the combined cooling and heating operation mode, when the compressor bypass condition is satisfied, the operation with the compressor of the specific usage unit can be appropriately stopped, and the compressor bypass condition is not satisfied. In addition, by operating all the compressors of the utilization unit that performs heating and cooling, efficient operation with two-stage compression can be performed.

  An air conditioner according to a fifth aspect is the first outdoor unit according to any of the air conditioners according to the first to third aspects, wherein the outdoor unit includes a first outdoor heat exchanger as an outdoor heat exchanger. And a second outdoor unit having a second outdoor heat exchanger as the outdoor heat exchanger. A state in which the first and second outdoor heat exchangers function as a refrigerant radiator or evaporator, and one of the first and second outdoor heat exchangers functions as a refrigerant radiator and the first and second outdoor heat It further has an outdoor side switching mechanism capable of switching between the state in which the other of the exchangers is made to function as a refrigerant evaporator. The first and second outdoor units are connected to the liquid refrigerant communication pipe and the gas refrigerant communication pipe via the outdoor switching mechanism.

  Here, since the first and second outdoor units are connected to the liquid refrigerant communication pipe and the gas refrigerant communication pipe via the outdoor switching mechanism, the outdoor heat exchanger functions as a refrigerant radiator for each outdoor unit. It is possible to set whether or not to function as a refrigerant evaporator. For this reason, here, among the two outdoor units, it is possible to set one that causes the outdoor heat exchanger to function as a radiator of the refrigerant and one that causes the outdoor heat exchanger to function as a refrigerant evaporator.

  Thereby, the operation which switches an outdoor unit which makes an outdoor heat exchanger function as a radiator of a refrigerant, and an outdoor unit which makes an outdoor heat exchanger function as an evaporator of a refrigerant can be performed by turns.

  An air conditioning apparatus according to a sixth aspect is the air conditioning apparatus according to the fifth aspect, further including a control unit that controls an outdoor unit including an outdoor switching mechanism and devices configuring a plurality of usage units. . The control unit includes an indoor heat exchanger that functions as a refrigerant radiator, and has an operation mode in which the first and second outdoor heat exchangers function as a refrigerant evaporator. Allowing the first outdoor heat exchanger to function as a refrigerant radiator and the second outdoor heat from a state in which the outdoor switching mechanism is operated and the first and second outdoor heat exchangers function as a refrigerant radiator or evaporator. The first outdoor heat exchanger is defrosted by switching the exchanger to a state of functioning as a refrigerant evaporator, and then the second outdoor heat exchanger is functioned as a refrigerant radiator and the first outdoor heat exchanger Is switched to a state of functioning as a refrigerant evaporator, thereby performing alternate defrost control for defrosting the second outdoor heat exchanger.

  Here, there is an indoor heat exchanger that functions as a refrigerant radiator, and there is at least one operating unit in which the first and second outdoor heat exchangers function as refrigerant evaporators, that is, heating is performed. There is an operation mode in which the outdoor heat exchanger functions as a refrigerant evaporator. When such an operation mode is continued, the outdoor heat exchanger frosts. For this reason, although it is necessary to perform a defrost by making an outdoor heat exchanger function as a radiator of a refrigerant temporarily, it is preferred at this time that heating of a utilization unit can also be continued.

  Therefore, here, the first outdoor heat exchanger and the second outdoor unit are utilized utilizing the fact that the first and second outdoor units are connected to the liquid refrigerant communication pipe and the gas refrigerant communication pipe via the outdoor switching mechanism. The alternate defrost control is performed to alternately defrost the heat exchangers.

  Thereby, here, in the operation mode in which at least one utilization unit performing heating operates and the outdoor heat exchanger functions as an evaporator of the refrigerant, the heating of the utilization units is continued while removing the two outdoor heat exchangers. It can do frost.

  As described above, according to the present invention, the following effects can be obtained.

  In the air conditioner according to the first aspect, the exhaust heat of the remote condenser type air conditioner is configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger. The cooling-heating mixed operation can be performed while collecting.

  In the air conditioner according to the second aspect, noise and vibration caused by the compressor can be suppressed in the living room. In addition, the number of compressor units can be reduced.

  In the air conditioning apparatus according to the third aspect, an operation can be performed in which a utilization unit that compresses the refrigerant by the compressor and a utilization unit that bypasses the refrigerant without compressing the refrigerant are mixed.

  In the air conditioning apparatus according to the fourth aspect, in the cooling and heating mixed operation mode, when the compressor bypass condition is satisfied, an operation can be performed in which the compressor of the specific usage unit is appropriately stopped, and the compressor bypass If the conditions are not satisfied, efficient operation with two-stage compression can be performed by operating all the compressors of the utilization unit that performs heating and cooling.

  In the air conditioner pertaining to the fifth aspect, the operation of alternately switching between an outdoor unit that causes the outdoor heat exchanger to function as a refrigerant radiator and an outdoor unit that causes the outdoor heat exchanger to function as a refrigerant evaporator may be performed. it can.

  In the air conditioner according to the sixth aspect, in the operation mode in which at least one usage unit for heating is present and the outdoor heat exchanger functions as an evaporator of the refrigerant, the heating of the usage unit is continued while the two outdoor units are maintained. The heat exchanger can be defrosted.

It is a schematic block diagram of the air conditioning apparatus concerning one Embodiment of this invention. It is a control block diagram of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant in the cooling only operation mode of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant in the heating all operation mode of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant in the heating / cooling operation mode (cooling main body) of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant at the time of compressor bypass control of the cooling / heating mixed operation mode (cooling main body) of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant in the heating / cooling operation mode (heating main body) of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant at the time of compressor bypass control of the heating / cooling operation mode (heating main body) of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant in the cooling / heating mixed operation mode (cooling / heating balance) of an air conditioning apparatus. It is a figure which shows the flow of the refrigerant | coolant at the time of compressor bypass control of the cooling / heating mixed operation mode (cooling / heating balance) of an air conditioning apparatus. It is a schematic block diagram (an outdoor unit is abbreviate | omitted and shown) of the air conditioning apparatus which connected several indoor units to the compressor unit. It is a schematic block diagram of the air conditioning apparatus which integrated the compressor unit and the indoor unit. It is a schematic block diagram (illustration abbreviate | omitted and shown some of utilization units) of the air conditioning apparatus of a modification. It is a figure which shows the flow of the refrigerant | coolant in the heating all operation mode of the air conditioning apparatus of a modification. It is a figure which shows the flow of the refrigerant | coolant at the time of alternate defrost control of the heating all operation mode of the air conditioning apparatus of a modification. It is a figure which shows the flow of the refrigerant | coolant at the time of alternate defrost control of the heating all operation mode of the air conditioning apparatus of a modification.

  Hereinafter, an embodiment of an air conditioner according to the present invention will be described based on the drawings. In addition, the specific structure of embodiment of the air conditioning apparatus concerning this invention is not restricted to following embodiment, It can change in the range which does not deviate from the summary of invention.

(1) Configuration FIG. 1 is a schematic configuration diagram of an air conditioner 1 according to an embodiment of the present invention. FIG. 2 is a control block diagram of the air conditioner 1. Next, the entire configuration of the air conditioner 1 will be described.

<Overall>
The air conditioner 1 is a remote condenser type air conditioner configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger, and is a vapor compression refrigeration cycle. By doing this, it is possible to perform indoor air conditioning in buildings and the like.

  Specifically, the air conditioner 1 has a plurality of (here, three) utilization units 3a, 3b, 3c, an outdoor unit 2, a liquid refrigerant communication pipe 6, and a gas refrigerant communication pipe 7. A plurality of utilization units 3a, 3b, 3c and the outdoor unit 2 are connected via the refrigerant communication pipes 6, 7 to constitute a refrigerant circuit 20 for performing a vapor compression type cycle. . Here, the utilization units 3a, 3b, 3c are provided in the building, and mainly, the compressors 41a, 41b, 41c, the indoor heat exchangers 52a, 52b, 52c, the indoor heat exchangers 52a, 52b, There are use side switching mechanisms 43a, 43b, 43c for switching between a state in which 52c functions as a refrigerant radiator and a state in which it functions as a refrigerant evaporator. In addition, the number of utilization units is not limited to three, and may be two or four or more. The outdoor unit 2 is provided outside the building, and mainly includes the outdoor heat exchanger 21 common to the plurality of usage units 3a, 3b, 3c. The liquid refrigerant communication pipe 6 is branched from the liquid refrigerant communication joint pipe 61 connected to the outdoor unit 2 so as to be in communication with the liquid side of the outdoor heat exchanger 21 and the liquid refrigerant communication joint pipe 61 and each indoor heat exchanger A plurality of liquid refrigerant communication branch pipes 62a, 62b, 62c connected to the respective usage units 3a, 3b, 3c are provided in communication with the liquid side of 52a, 52b, 52c. The gas refrigerant communication pipe 7 is branched from the gas refrigerant communication joint pipe 71 connected to the outdoor unit 2 so as to be in communication with the gas side of the outdoor heat exchanger 21 and the gas refrigerant communication joint pipe 71 to use each side switching mechanism A plurality of gas refrigerant communication branch pipes 72a, 72b, 72c are connected to the utilization units 3a, 3b, 3c in communication with the 43a, 43b, 43c. Thus, in this case, the outdoor unit 2 having the outdoor heat exchanger 21 is configured by connecting the usage units 3a, 3b, 3c having the compressors 41a, 41b, 41c and the indoor heat exchangers 52a, 52b, 52c. In the remote condenser type air conditioner 1 of the above, first, the use side switching mechanisms 43a, 43b, 43c are provided to the respective use units 3a, 3b, 3c, thereby cooling and heating in the respective use units 3a, 3b, 3c. Is made to be able to be switched. In addition, the outdoor heat exchanger 21 is shared by the plurality of usage units 3a, 3b, 3c, and the liquid side of the outdoor heat exchanger 21 in the liquid refrigerant communication pipe 6 is on the liquid side of each indoor heat exchanger 52a, 52b, 52c. It branches so as to communicate and connects to each usage unit 3a, 3b, 3c, and branches so that the gas side of the outdoor heat exchanger 21 communicates with each usage side switching mechanism 43a, 43b, 43c in the gas refrigerant communication pipe 7. The outdoor heat exchanger 21 forms a common refrigerant system (refrigerant circuit 20) to the plurality of usage units 3a, 3b, 3c by connecting the usage units 3a, 3b, 3c. For this reason, here, when performing an operation (cooling and heating mixed operation) in which the usage unit performing cooling and the usage unit performing heating coexist, the refrigerant communication pipe between the usage unit performing cooling and the usage unit performing heating Using the outdoor heat exchanger 21 as a refrigerant radiator or evaporator according to the difference between the cooling load in the utilization unit performing cooling and the heating load in the utilization unit performing heating while exchanging the refrigerant through 6 and 7 It is possible to Next, the detailed configuration of the air conditioner 1 will be described.

<Outdoor unit>
The outdoor unit 2 is installed outdoors as described above, and constitutes a part of the refrigerant circuit 20. The outdoor unit 2 mainly includes an outdoor heat exchanger 21 and an outdoor expansion mechanism 22.

  The outdoor heat exchanger 21 is a heat exchanger for performing heat exchange between the refrigerant and the outdoor air. The gas side of the outdoor heat exchanger 21 is connected to the gas refrigerant communication junction pipe 71 of the gas refrigerant communication pipe 7, and the liquid side is connected to the outdoor expansion mechanism 22. Here, the outdoor unit 2 has an outdoor fan 23 for drawing the outdoor air into the outdoor unit 2 and exchanging heat with the refrigerant in the outdoor heat exchanger 21 and thereafter discharging the heat to the outside. That is, the outdoor unit 2 includes the outdoor fan 23 as a fan that supplies the outdoor heat exchanger 21 with outdoor air as a cooling source or a heating source of the refrigerant flowing through the outdoor heat exchanger 21. Here, a propeller fan or the like driven by the outdoor fan motor 24 is used as the outdoor fan 23.

  The outdoor expansion mechanism 22 is a mechanism for adjusting the flow rate of the refrigerant flowing through the outdoor heat exchanger 21 and the like. One end of the outdoor expansion mechanism 22 is connected to the liquid side of the outdoor heat exchanger 21, and the other end is connected to the liquid refrigerant communication merging pipe 61 of the liquid refrigerant communication pipe 6. Here, an electric expansion valve capable of adjusting the opening degree is used as the outdoor expansion mechanism 22.

  In addition, the outdoor unit 2 is provided with various sensors. Specifically, an outdoor heat exchange temperature sensor 25 for detecting the temperature of the refrigerant in the outdoor heat exchanger 21 and an outside air temperature sensor 26 for detecting the outside air temperature are provided.

<Usage unit>
The utilization units 3a, 3b, 3c are installed indoors as described above, and constitute a part of the refrigerant circuit 20. Here, the usage unit 3a mainly includes the compressor unit 4a including the compressor 41a and the indoor unit 5a including the indoor heat exchanger 52a, and the compressor unit 4a and the indoor unit 5a are used It is connected via the side refrigerant | coolant communication pipes 8a and 9a. Further, similarly to the usage unit 3a, the usage unit 3b mainly includes the compressor unit 4b including the compressor 41b and the indoor unit 5b including the indoor heat exchanger 52b, and the compressor unit 4b and the indoor The unit 5b is connected via the use side refrigerant communication pipes 8b and 9b. Furthermore, as in the usage units 3a and 3b, the usage unit 3c mainly includes a compressor unit 4c including a compressor 41c and an indoor unit 5c including an indoor heat exchanger 52c, and the compressor unit 4c The indoor unit 5c and the indoor unit 5c are connected via the use side refrigerant communication pipes 8c and 9c. The usage units 3b and 3c have the same configuration as the usage unit 3a, so in the following description, the configuration of the usage unit 3a (here, the compressor unit 4a and the indoor unit 5a, the usage-side refrigerant communication tube 8a, Only the configuration 9a) will be described, and the configuration of the usage units 3b and 3c will be omitted by replacing the subscript "a" of the reference numeral indicating each portion of the usage unit 3a with the subscript "b" or "c".

-Compressor unit-
The compressor unit 4a mainly includes a compressor 41a, a use side switching mechanism 43a, and a compressor bypass pipe 44a.

  The compressor 41a is a device for compressing the refrigerant and circulating the refrigerant. Here, the compressor 41a has a structure in which a rotary type or scroll type positive displacement compression element (not shown) is rotationally driven by a compressor motor 42a whose frequency (rotational speed) can be controlled by an inverter. . That is, the compressor 41a is configured to be able to control the operating capacity by changing the frequency (rotational speed). Both the suction side and the discharge side of the compressor 41a are connected to the use side switching mechanism 43a.

  The use side switching mechanism 43a is a mechanism for switching the flow direction of the refrigerant in the use unit 3a. The use side switching mechanism 43a switches the indoor heat exchanger 52a to a cooling cycle state that causes the indoor heat exchanger 52a to function as a refrigerant evaporator when cooling the usage unit 3a, and heats the indoor heat exchanger 52a as a refrigerant radiator when heating the usage unit 3a. Switch to the heating cycle state to act as. That is, at the time of cooling, the use side switching mechanism 43a connects the suction side of the compressor 41a and the gas side of the indoor heat exchanger 52a via the use side gas refrigerant communication pipe 9a (the use side switching mechanism 43a in FIG. 1). See the solid line of). Moreover, the discharge side of the compressor 41a and the gas refrigerant communication branch pipe 72a of the gas refrigerant communication pipe 7 are connected (see the solid line of the use side switching mechanism 43a in FIG. 1). In addition, at the time of heating, the use side switching mechanism 43a connects the discharge side of the compressor 41a and the gas side of the indoor heat exchanger 52a via the use side gas refrigerant communication pipe 9a (the use side switching mechanism 43a in FIG. 1). See the dashed line). Moreover, the suction side of the compressor 41a and the gas refrigerant communication branch pipe 72a of the gas refrigerant communication pipe 7 are connected (see the broken line of the use side switching mechanism 43a in FIG. 1). Here, a four-way switching valve is used as the use-side switching mechanism 43a, but by configuring a circuit configuration combining a plurality of on-off valves, a configuration similar to that of the four-way switching valve can be achieved. You may

  The compressor bypass pipe 44a is a refrigerant pipe capable of bypassing the compressor 41a and sending the refrigerant from the suction side of the compressor 41a to the discharge side of the compressor 41a in the compressor unit 4a. One end of the compressor bypass pipe 44a is connected between the use side switching mechanism 43a and the suction side of the compressor 41a, and the other end is between the discharge side of the compressor 41a and the use side switching mechanism 43a. It is connected. And the non-return mechanism 45a which accept | permits only the flow of the refrigerant | coolant from the suction side of the compressor 41a to the discharge side of the compressor 41a is provided in the compressor bypass pipe 44a. Although a check valve is used as the non-return mechanism 45a here, an on-off valve or the like may be used.

  Moreover, various sensors are provided in the compressor unit 4a. Specifically, a suction / discharge pressure sensor 46a is provided which detects the pressure of the refrigerant flowing between the use side switching mechanism 43a and the gas side of the indoor heat exchanger 52a. Here, the pressure of the refrigerant on the suction side of the compressor 41a is detected by the suction / discharge pressure sensor 46a during cooling of the use unit 3a, and the pressure of the refrigerant on the discharge side of the compressor 41a is calculated during heating of the use unit 3a. Although detection is possible, pressure sensors may be provided on the suction side of the compressor 41a and the discharge side of the compressor 41a.

-Indoor unit-
The indoor unit 5a mainly includes a use side expansion mechanism 51a and an indoor heat exchanger 52a.

  The use side expansion mechanism 51a is a mechanism for adjusting the flow rate of the refrigerant flowing through the indoor heat exchanger 52a and the like. One end of the utilization side expansion mechanism 51a is connected to the liquid refrigerant communication branch pipe 62a of the liquid refrigerant communication pipe 6 via the utilization side liquid refrigerant communication pipe 8a, and the other end is connected to the liquid side of the indoor heat exchanger 52a ing. Here, an electric expansion valve capable of adjusting the opening degree is used as the use side expansion mechanism 51a.

  The indoor heat exchanger 52a is a heat exchanger for performing heat exchange between the refrigerant and the indoor air. The gas side of the indoor heat exchanger 52a is connected to the use side switching mechanism 43a via the use side gas refrigerant communication pipe 9a, and the liquid side is connected to the use side expansion mechanism 51a. Here, the indoor unit 5a has an indoor fan 53a for supplying the indoor air after the indoor air is sucked into the indoor unit 5a and heat-exchanged with the refrigerant in the indoor heat exchanger 52a. That is, the indoor unit 5a includes the indoor fan 53a as a fan that supplies indoor air as a cooling source or a heating source of the refrigerant flowing through the indoor heat exchanger 52a to the indoor heat exchanger 52a. Here, as the indoor fan 53a, a centrifugal fan, a multi-blade fan or the like driven by the indoor fan motor 54a is used.

-Utilization side refrigerant communication pipe-
The utilization side liquid refrigerant communication pipe 8a is a refrigerant pipe for exchanging liquid refrigerant between the liquid refrigerant communication branch pipe 62a of the liquid refrigerant communication pipe 6 and the utilization side expansion mechanism 51a of the indoor unit 5a through the compressor unit 4a. is there.

  The utilization side gas refrigerant communication pipe 9a is a refrigerant pipe for exchanging a gas refrigerant between the utilization side switching mechanism 43a of the compressor unit 4a and the gas side of the indoor heat exchanger 52a of the indoor unit 5a.

<Control unit>
The air conditioner 1 controls the operation of the devices that constitute the outdoor unit 2 and the usage units 3a, 3b, 3c (here, the compressor units 4a, 4b, 4c and the indoor units 5a, 5b, 5c). have. The control unit 10 is a micro controller provided to control each of the outdoor unit 2 and the usage units 3a, 3b, 3c (here, the compressor units 4a, 4b, 4c and the indoor units 5a, 5b, 5c). It has a computer, memory, etc. In addition, although the control part 10 is illustrated as what is provided in the outdoor unit 2 here for convenience, the actual control part 10 is the outdoor unit 2 and utilization unit 3a, 3b, 3c (here, compression The control units of the machine units 4a, 4b, 4c and the indoor units 5a, 5b, 5c) are connected by communication. The control unit 10 performs various operations such as cooling and heating described below.

(2) Operation and Control FIG. 3 is a diagram showing the flow of the refrigerant in the cooling only operation mode of the air conditioner 1. FIG. 4 is a diagram showing the flow of the refrigerant in the heating only operation mode of the air conditioner 1. FIG. 5 is a diagram showing the flow of the refrigerant in the mixed heating and operation mode (mainly cooling) of the air conditioner 1. FIG. 6 is a diagram showing the flow of the refrigerant at the time of the compressor bypass control in the mixed heating operation mode (cooling main operation) of the air conditioner 1. FIG. 7 is a diagram showing the flow of the refrigerant in the heating / cooling mixed operation mode (mainly heating) of the air conditioning apparatus 1. FIG. 8 is a view showing the flow of the refrigerant at the time of the compressor bypass control in the mixed heating operation mode (mainly heating) of the air conditioner 1. FIG. 9 is a diagram showing the flow of the refrigerant in the combined heating and cooling operation mode (cooling and heating balance) of the air conditioner 1. FIG. 10 is a diagram showing the flow of the refrigerant at the time of the compressor bypass control in the combined heating and cooling operation mode (cooling and heating balance) of the air conditioner 1. Next, the operation and control of the air conditioner 1 will be described.

<Full cooling operation mode>
In the cooling only operation mode, for example, all of the use units 3a, 3b, 3c perform the cooling operation (that is, all the indoor heat exchangers 52a, 52b, 52c function as a refrigerant evaporator), and outdoor heat exchange When the condenser 21 functions as a refrigerant radiator, the refrigerant circuit 20 of the air conditioner 1 is configured as shown in FIG. 3 (for the flow of the refrigerant, the arrow attached to the refrigerant circuit 20 of FIG. reference).

  Specifically, in the use units 3a, 3b, 3c (here, the compressor units 4a, 4b, 4c), the use side switching mechanisms 43a, 43b, 43c are in the cooling cycle state (indicated by solid lines in FIG. 3) By switching to the state), all the indoor heat exchangers 52a, 52b, 52c of the usage units 3a, 3b, 3c (here, the indoor units 5a, 5b, 5c) function as a refrigerant evaporator and the outdoor unit The two outdoor heat exchangers 21 function as radiators for the refrigerant.

  In such a refrigerant circuit 20, the high-pressure gas refrigerant of the refrigeration cycle compressed and discharged by the compressors 41a, 41b, 41c passes through the use side switching mechanisms 43a, 43b, 43c to use units 3a, 3b, 3c (herein Then, the compressor unit 4a, 4b, 4c) sends it to the gas refrigerant communication branch pipes 72a, 72b, 72c.

  Then, the high-pressure gas refrigerants sent to the gas refrigerant communication branch pipes 72a, 72b and 72c are sent from the gas refrigerant communication pipe 7 to the outdoor heat exchanger 21 of the outdoor unit 2 after joining in the gas refrigerant communication junction pipe 71. Be

  Then, the high-pressure gas refrigerant sent to the outdoor heat exchanger 21 releases heat by heat exchange with the outdoor air as a cooling source supplied by the outdoor fan 23 in the outdoor heat exchanger 21. The high-pressure refrigerant that has dissipated heat in the outdoor heat exchanger 21 is sent from the outdoor unit 2 to the liquid refrigerant communication merging pipe 61 of the liquid refrigerant communication pipe 6 through the outdoor expansion mechanism 22.

  Then, the refrigerant sent to the liquid refrigerant communication merging pipe 61 is branched to the liquid refrigerant communication branch pipes 62a, 62b and 62c, and then the refrigerant of the utilization units 3a, 3b and 3c (here, the indoor units 5a, 5b and 5c). It is sent to the use side expansion mechanism 51a, 51b, 51c. Specifically, the refrigerant branched into the liquid refrigerant communication branch pipes 62a, 62b and 62c passes through the compressor units 4a, 4b and 4c and the use side liquid refrigerant communication pipes 8a, 8b and 8c to produce the indoor units 5a, 5b and 5c, respectively. 5c is sent to the use side expansion mechanism 51a, 51b, 51c.

  Then, the refrigerant sent to the use side expansion mechanisms 51a, 51b, 51c is adjusted in flow rate by the use side expansion mechanisms 51a, 51b, 51c, and then the indoor fans 53a, 53b are made in the indoor heat exchangers 52a, 52b, 52c. , 53c by heat exchange with the room air supplied to the low pressure gas refrigerant. On the other hand, the indoor air is cooled and supplied indoors to cool the use units 3a, 3b, 3c. Low-pressure gas refrigerant evaporated in the indoor heat exchangers 52a, 52b, 52c is transferred to the use-side switching mechanisms 43a, 43b, 43c of the compressor units 4a, 4b, 4c through the use-side gas refrigerant communication pipes 9a, 9b, 9c. Sent. The low-pressure gas refrigerant sent to the use side switching mechanisms 43a, 43b, 43c is returned to the suction side of the compressors 41a, 41b, 41c and compressed again.

  Thus, the operation in the cooling only operation mode is performed. In addition, although all the utilization units 3a, 3b, and 3c demonstrated cooling in this case, it is not limited to this, For example, any one or two of utilization units 3a, 3b, 3c Even when cooling is performed to stop another usage unit, it is included in the cooling only operation mode.

  Further, in such a cooling only operation mode, for example, for the use units 3a, 3b, 3c for cooling, target values of suction pressures (low pressure of the refrigeration cycle) of the compressors 41a, 41b, 41c are used for each use unit. The operating capacities of the compressors 41a, 41b, 41c may be controlled so as to obtain such target values. Here, as the actual measurement value of the suction pressure of the compressors 41a, 41b, 41c, the pressure of the refrigerant detected by the suction / discharge pressure sensors 46a, 46b, 46c can be used.

<All heating operation mode>
In the all heating operation mode, for example, all of the use units 3a, 3b, 3c perform heating operation (that is, all the indoor heat exchangers 52a, 52b, 52c function as a radiator of refrigerant), and outdoor heat exchange When the unit 21 functions as a refrigerant evaporator, the refrigerant circuit 20 of the air conditioner 1 is configured as shown in FIG. 4 (for the flow of the refrigerant, the arrows attached to the refrigerant circuit 20 in FIG. reference).

  Specifically, in the use units 3a, 3b, 3c (here, the compressor units 4a, 4b, 4c), the use side switching mechanisms 43a, 43b, 43c are in the heating cycle state (indicated by the broken line in FIG. 4) By switching to the state), all the indoor heat exchangers 52a, 52b, 52c of the utilization units 3a, 3b, 3c (here, the indoor units 5a, 5b, 5c) function as a radiator of the refrigerant and the outdoor unit The two outdoor heat exchangers 21 are in a state of functioning as a refrigerant evaporator.

  In such a refrigerant circuit 20, the high pressure gas refrigerant of the refrigeration cycle compressed and discharged by the compressors 41a, 41b, 41c is used side switching mechanisms 43a, 43b, 43c and used side gas refrigerant communication pipes 9a, 9b, The heat is sent to the indoor heat exchangers 52a, 52b, 52c of the usage units 3a, 3b, 3c (here, the indoor units 5a, 5b, 5c) through 9c. The high-pressure gas refrigerant sent to the indoor heat exchangers 52a, 52b, 52c exchanges heat with the indoor air supplied by the indoor fans 53a, 53b, 53c in the indoor heat exchangers 52a, 52b, 52c. It releases heat and becomes a high pressure refrigerant. On the other hand, indoor air is heated and supplied indoors, and heating of utilization unit 3a, 3b, 3c is performed. The high-pressure refrigerant that has dissipated heat in the indoor heat exchangers 52a, 52b, 52c is sent to the use side expansion mechanisms 51a, 51b, 51c. The refrigerant sent to the use side expansion mechanisms 51a, 51b, 51c is adjusted in flow rate by the use side expansion mechanisms 51a, 51b, 51c, and then the use side liquid refrigerant communication pipes 8a, 8b, 8c and the compressor units 4a, 4b , 4c, from the utilization units 3a, 3b, 3c to the liquid refrigerant communication branch pipes 62a, 62b, 62c of the liquid refrigerant communication pipe 6.

  Then, the refrigerants sent to the liquid refrigerant communication branch pipes 62a, 62b and 62c are sent from the liquid refrigerant communication pipe 6 to the outdoor expansion mechanism 22 of the outdoor unit 2 after joining in the liquid refrigerant communication joint pipe 61.

  Then, after the flow rate of the refrigerant sent to the outdoor expansion mechanism 22 is adjusted in the outdoor expansion mechanism 22, heat exchange is performed with the outdoor air as a heat source supplied by the outdoor fan 23 in the outdoor heat exchanger 21. Evaporates into a low pressure gas refrigerant. The low pressure gas refrigerant evaporated in the outdoor heat exchanger 21 is sent from the outdoor unit 2 to the gas refrigerant communication merging pipe 71 of the gas refrigerant communication pipe 7.

  Then, the low pressure gas refrigerant sent to the gas refrigerant communication junction pipe 71 is branched into the gas refrigerant communication branch pipes 72a, 72b, 72c, and then used units 3a, 3b, 3c (here, the compressor units 4a, 4b, 4c) is sent to the use side switching mechanism 43a, 43b, 43c. The low-pressure gas refrigerant sent to the use side switching mechanisms 43a, 43b, 43c is returned to the suction side of the compressors 41a, 41b, 41c and compressed again.

  Thus, the operation in the heating only operation mode is performed. Here, although the case where all of utilization units 3a, 3b, 3c heats was explained, it is not limited to this, for example, any one or two of utilization units 3a, 3b, 3c When heating and stopping other usage units are also included in the all heating operation mode.

  In such a heating only operation mode, for example, for the usage units 3a, 3b, 3c for heating, target values of discharge pressure (high pressure of the refrigeration cycle) of the compressors 41a, 41b, 41c for each usage unit The operating capacities of the compressors 41a, 41b, 41c may be controlled so as to obtain such target values. Here, as the actual measurement value of the discharge pressure of the compressors 41a, 41b, 41c, the pressure of the refrigerant detected by the suction / discharge pressure sensors 46a, 46b, 46c can be used.

<Heating / cooling mixed operation mode>
-Mainly cooling-
In the cooling / heating mixed operation mode (mainly cooling), for example, the use units 3a and 3b are for cooling, and the use unit 3c is for heating (that is, the indoor heat exchangers 52a and 52b function as a refrigerant evaporator and indoors) When the heat exchanger 52c functions as a radiator of refrigerant and the outdoor heat exchanger 21 functions as a radiator of refrigerant, the refrigerant circuit 20 of the air conditioner 1 is configured as shown in FIG. (For the flow of the refrigerant, refer to the arrow attached to the refrigerant circuit 20 in FIG. 5).

  Specifically, in the use units 3a and 3b (here, the compressor units 4a and 4b), the use side switching mechanisms 43a and 43b are switched to the cooling cycle state (the state shown by the solid line in FIG. 5) , Utilization unit 3c (here, in the compressor unit 4c), utilization unit 3a, 3b (here, by changing the utilization side switching mechanism 43c to the heating cycle state (state shown by the broken line in FIG. 5). The indoor heat exchangers 52a and 52b of the indoor units 5a and 5b) function as a refrigerant evaporator, and the indoor heat exchanger 52c of the usage unit 3c (here, the indoor unit 5c) function as a refrigerant radiator At the same time, the outdoor heat exchanger 21 of the outdoor unit 2 functions as a refrigerant radiator.

  In such a refrigerant circuit 20, the high-pressure gas refrigerant of the refrigeration cycle compressed and discharged by the compressors 41a and 41b passes through the use side switching mechanisms 43a and 43b to use units 3a and 3b (here, the compressor unit 4a). , 4b) to the gas refrigerant communication branch pipes 72a, 72b.

  Then, after the high-pressure gas refrigerants sent to the gas refrigerant communication branch pipes 72a and 72b merge in the gas refrigerant communication joint pipe 71, a part of the high pressure gas refrigerants passes through the gas refrigerant communication branch pipe 72c and the utilization unit 3c (here, compression The remaining portion is sent from the gas refrigerant communication pipe 7 to the outdoor heat exchanger 21 of the outdoor unit 2.

  Then, the high-pressure gas refrigerant sent to the use side switching mechanism 43c is compressed and discharged by the compressor 41c. The gas refrigerant discharged from the compressor 41c is sent to the indoor heat exchanger 52c of the use unit 3c (here, the indoor unit 5c) through the use side switching mechanism 43c and the use side gas refrigerant communication pipe 9c. The high-pressure gas refrigerant sent to the indoor heat exchanger 52c exchanges heat with the indoor air supplied by the indoor fan 53c in the indoor heat exchanger 52c, thereby releasing heat and becoming a high-pressure refrigerant. On the other hand, the room air is heated and supplied indoors to heat the usage unit 3c. The high-pressure refrigerant that has dissipated heat in the indoor heat exchanger 52c is sent to the use-side expansion mechanism 51c. The flow rate of the refrigerant sent to the use side expansion mechanism 51c is adjusted by the use side expansion mechanism 51c, and then the liquid refrigerant in the liquid refrigerant communication pipe 6 from the use unit 3c is transmitted through the use side liquid refrigerant communication pipe 8c and the compressor unit 4c. It is sent to the contact branch pipe 62c.

  Further, the high-pressure gas refrigerant sent to the outdoor heat exchanger 21 releases heat by heat exchange with the outdoor air as a cooling source supplied by the outdoor fan 23 in the outdoor heat exchanger 21. The high-pressure refrigerant that has dissipated heat in the outdoor heat exchanger 21 is sent from the outdoor unit 2 to the liquid refrigerant communication merging pipe 61 of the liquid refrigerant communication pipe 6 through the outdoor expansion mechanism 22.

  Then, the refrigerant sent from the liquid refrigerant communication branch pipe 62c is joined to the liquid refrigerant communication branch pipe 61c, and the refrigerant is further branched into the liquid refrigerant communication branch pipes 62a and 62b. , Sent to the use-side expansion mechanism 51a, 51b of the indoor unit 5a, 5b). Specifically, the refrigerant branched into the liquid refrigerant communication branch pipes 62a, 62b is used side expansion mechanism 51a of the indoor units 5a, 5b through the compressor units 4a, 4b and the use side liquid refrigerant communication pipes 8a, 8b, Sent to 51b.

  The refrigerant sent to the use side expansion mechanisms 51a and 51b is adjusted in flow rate by the use side expansion mechanisms 51a and 51b, and then the indoor air supplied by the indoor fans 53a and 53b in the indoor heat exchangers 52a and 52b. And heat exchange to evaporate the low pressure gas refrigerant. On the other hand, indoor air is cooled and supplied indoors to cool the use units 3a and 3b. The low pressure gas refrigerant evaporated in the indoor heat exchangers 52a and 52b is sent to the use side switching mechanisms 43a and 43b of the compressor units 4a and 4b through the use side gas refrigerant communication pipes 9a and 9b. The low-pressure gas refrigerant sent to the use side switching mechanisms 43a and 43b is returned to the suction side of the compressors 41a and 41b and compressed again.

  In this manner, the operation in the cooling / heating mixed operation mode (mainly cooling) is performed. Although the case where the use units 3a and 3b perform cooling and the use unit 3c perform heating has been described here, the invention is not limited thereto, and a use unit for performing cooling and a use unit for performing heating And the combined cooling load of the plurality of utilization units 3a, 3b, 3c is greater than the heating load, and the outdoor heat exchanger 21 functions as a radiator of the refrigerant, the cooling / heating mixed operation mode Included in (Cooling mainly).

  Also, in such a combined cooling / heating operation mode (mainly cooling), for the use units 3a and 3b for cooling, for example, target values of the suction pressure (low pressure of the refrigeration cycle) of the compressors 41a and 41b are used for each use unit. The target value of discharge pressure (high pressure of the refrigeration cycle) of the compressor 41c is set for the use unit 3c that sets and heats, and the operating capacity of the compressors 41a, 41b, 41c is obtained so as to obtain such a target value. May be controlled. Here, as the actual measurement values of the suction pressure and the discharge pressure of the compressors 41a, 41b and 41c, the pressure of the refrigerant detected by the suction / discharge pressure sensors 46a, 46b and 46c can be used.

  Further, in the above-mentioned combined cooling / heating operation mode (mainly cooling), the refrigerant compressed by the compressor 41c in the utilization unit 3c is compressed by the compressor 41a, 41b of the utilization units 3a, 3b (i.e., two stages) Since heating using a compressed refrigerant is performed, efficient operation is possible. In particular, it is particularly effective under the condition that the outside air temperature is low and the pressure difference with the high pressure in the indoor heat exchanger (in the above, the indoor heat exchanger 52c) performing heating and high pressure in the outdoor heat exchanger 21 becomes large.

  However, conversely, heating is performed under the condition that the outside air temperature is high and the pressure difference with the high pressure in the indoor heat exchanger (in the above, the indoor heat exchanger 52c) performing the high pressure and heating in the outdoor heat exchanger 21 is small. Even if compression of the refrigerant is not performed by the compressor 41c of the utilization unit (here, utilization unit 3c), heating is performed with the high-pressure refrigerant sent from the utilization units (here, utilization units 3a, 3b) performing cooling. Can.

  Therefore, in this case, a condition where heating can be performed without compression of the refrigerant in the specific usage unit as described above is set as the compressor bypass condition, and in the case where the compressor bypass condition is satisfied, The compressor bypass control is performed using the compressor bypass pipes 44a, 44b, and 44c provided in the usage units 3a, 3b, and 3c.

  Specifically, for example, when the outside air temperature is higher than a predetermined outside air temperature, or the pressure difference between the high pressure in the outdoor heat exchanger 21 and the high pressure in the indoor heat exchanger that performs heating is smaller than a predetermined pressure difference In this case, it is determined that the compressor bypass condition is satisfied, and the compressor bypass control as shown in FIG. 6 is performed. That is, the compressor 41c is stopped in the usage unit 3c for heating (the usage unit 3c corresponding to the indoor heat exchanger 52c functioning as a refrigerant radiator) in the same cooling / heating mixed operation (see FIG. 5) as described above. The compressor bypass control is performed to bypass the compressor 41c stopped via the compressor bypass pipe 44c and send it from the suction side of the compressor 41c stopping the refrigerant to the discharge side of the compressor 41c stopped.

  Thereby, here, when the compressor bypass condition is satisfied in the cooling / heating mixed operation mode (cooling main), the compressor 41c of the specific usage unit (here, usage unit 3c for heating) is appropriately stopped. When the compressor bypass condition is not satisfied, the efficiency with two-stage compression can be achieved by operating all the compressors 41a, 41b, 41c of the utilization units 3a, 3b, 3c that perform heating and cooling. Good driving.

  As the outside air temperature used as the compressor bypass condition, the temperature detected by the outside air temperature sensor 26 can be used. Further, the pressure difference between the high pressure in the outdoor heat exchanger 21 and the high pressure in the indoor heat exchanger for heating is detected by the suction / discharge pressure sensor of the utilization unit for cooling that is among the suction / discharge pressure sensors 46a, 46b, 46c. The pressure difference between the refrigerant pressure and the refrigerant pressure detected by the suction / discharge pressure sensor of the utilization unit performing heating can be used.

-Mainly heating-
In the cooling / heating mixed operation mode (mainly heating), for example, the usage unit 3a is for cooling, and the usage units 3b and 3c are for heating (that is, the indoor heat exchanger 52a functions as a refrigerant evaporator, and indoor heat exchange When the outdoor heat exchanger 21 functions as a refrigerant evaporator, the refrigerant circuit 20 of the air conditioner 1 is configured as shown in FIG. 7. (For the flow of the refrigerant, refer to the arrow attached to the refrigerant circuit 20 in FIG. 7).

  Specifically, in the use unit 3a (here, the compressor unit 4a), the use side switching mechanism 43a is switched to the cooling cycle state (the state shown by the solid line in FIG. 7), and the use units 3b and 3c. (Here, in the compressor units 4b and 4c), the use unit 3a (here, the indoor unit) is switched by switching the use side switching mechanism 43b and 43c to the heating cycle state (state shown by the broken line in FIG. 7). The indoor heat exchanger 52a of 5a) functions as a refrigerant evaporator, and the indoor heat exchangers 52b and 52c of the usage units 3b and 3c (here, the indoor units 5b and 5c) function as a refrigerant radiator. At the same time, the outdoor heat exchanger 21 of the outdoor unit 2 functions as an evaporator of the refrigerant.

  In such a refrigerant circuit 20, the high-pressure gas refrigerant of the refrigeration cycle compressed and discharged by the compressor 41a passes from the utilization unit 3a (here, the compressor unit 4a) through the utilization-side switching mechanism 43a. It is sent to the pipe 72a.

  Then, the high pressure gas refrigerant sent to the gas refrigerant communication branch pipe 72a passes through the gas refrigerant communication joint pipe 71 and the gas refrigerant communication branch pipes 72b and 72c to the utilization units 3b and 3c (here, the compressor units 4b and 4c). Is sent to the user side switching mechanism 43b, 43c.

  Then, the high pressure gas refrigerant sent to the use side switching mechanisms 43b and 43c is compressed and discharged by the compressors 41b and 41c. The gas refrigerant discharged from the compressors 41b and 41c is used as the indoor heat of the use units 3b and 3c (here, the indoor units 5b and 5c) through the use side switching mechanisms 43b and 43c and the use side gas refrigerant communication pipes 9b and 9c. It is sent to the exchangers 52b and 52c. The high-pressure gas refrigerant sent to the indoor heat exchangers 52b and 52c dissipates heat by exchanging heat with the indoor air supplied by the indoor fans 53b and 53c in the indoor heat exchangers 52b and 52c, and thus the high-pressure refrigerant become. On the other hand, indoor air is heated and supplied indoors, and heating of utilization units 3b and 3c is performed. The high-pressure refrigerant that has dissipated heat in the indoor heat exchangers 52b and 52c is sent to the use side expansion mechanisms 51b and 51c. The refrigerant sent to the use side expansion mechanisms 51b and 51c is adjusted in flow rate by the use side expansion mechanisms 51b and 51c, and then used through the use side liquid refrigerant communication pipes 8b and 8c and the compressor units 4b and 4c, the use unit 3b, It is sent to the liquid refrigerant communication branch pipes 62b and 62c of the liquid refrigerant communication pipe 6 from 3c.

  Then, after the refrigerants sent to the liquid refrigerant communication branch pipes 62b and 62c merge in the liquid refrigerant communication joint pipe 61, a part of the refrigerant is used through the liquid refrigerant communication branch pipe 62a (here, the indoor unit 5a) The remaining portion is sent from the liquid refrigerant communication pipe 6 to the outdoor expansion mechanism 22 of the outdoor unit 2. Specifically, the refrigerant branched into the liquid refrigerant communication branch pipe 62a is sent to the use side expansion mechanism 51a of the indoor unit 5a through the compressor unit 4a and the use side liquid refrigerant communication pipe 8a.

  Then, the refrigerant sent to the use side expansion mechanism 51a is evaporated by performing heat exchange with the indoor air supplied by the indoor fan 53a in the indoor heat exchanger 52a after the flow rate is adjusted in the use side expansion mechanism 51a. It becomes a low pressure gas refrigerant. On the other hand, the room air is cooled and supplied indoors to cool the use unit 3a. The low-pressure gas refrigerant evaporated in the indoor heat exchanger 52a is sent to the use-side switching mechanism 43a of the compressor unit 4a through the use-side gas refrigerant communication pipe 9a. The low-pressure gas refrigerant sent to the use side switching mechanism 43a is returned to the suction side of the compressor 41a and compressed again.

  In addition, after the flow rate of the refrigerant sent to the outdoor expansion mechanism 22 is adjusted in the outdoor expansion mechanism 22, heat exchange is performed with the outdoor air as a heat source supplied by the outdoor fan 23 in the outdoor heat exchanger 21. Evaporates into a low pressure gas refrigerant. The low-pressure gas refrigerant evaporated in the outdoor heat exchanger 21 is sent from the outdoor unit 2 to the gas refrigerant communication junction pipe 71 of the gas refrigerant communication pipe 7, and merges with the gas refrigerant from the gas refrigerant communication branch pipe 72a.

  Thus, the operation in the heating / cooling mixed operation mode (mainly heating) is performed. Although the case where the usage unit 3a performs cooling and the usage units 3b and 3c perform heating has been described here, the present invention is not limited thereto, and a usage unit that performs cooling and a usage unit that performs heating And the combined heating load of the plurality of utilization units 3a, 3b, 3c is greater than the cooling load, and the outdoor heat exchanger 21 functions as a radiator of the refrigerant, the cooling / heating mixed operation mode Included in (Heating mainly).

  Further, in such a cooling / heating mixed operation mode (mainly heating), for example, a target value of suction pressure (low pressure of the refrigeration cycle) of the compressor 41a is set for the usage unit 3a for cooling, and the usage unit for heating For 3b and 3c, set target values for the discharge pressure (high pressure of the refrigeration cycle) of the compressors 41b and 41c for each usage unit, and the operating capacities of the compressors 41a, 41b and 41c so that such target values can be obtained. May be controlled. Here, as the actual measurement values of the suction pressure and the discharge pressure of the compressors 41a, 41b and 41c, the pressure of the refrigerant detected by the suction / discharge pressure sensors 46a, 46b and 46c can be used.

  Further, in the above-mentioned combined cooling / heating operation mode (mainly heating), in the use units 3b and 3c, the refrigerant compressed by the compressor 41a of the use unit 3a is further compressed by the compressors 41b and 41c (ie, two stages Since heating using a compressed refrigerant is performed, efficient operation is possible. In particular, it is particularly effective under the condition that the outside air temperature is high and the pressure difference with the low pressure in the indoor heat exchanger (in the above, the indoor heat exchanger 52a) performing cooling and the low pressure in the outdoor heat exchanger 21 becomes large.

  However, conversely, cooling is performed under the condition that the outside air temperature is low and the pressure difference with the low pressure in the indoor heat exchanger (in the above, the indoor heat exchanger 52a) performing cooling with the low pressure in the outdoor heat exchanger 21 becomes small. Even if compression of the refrigerant is not performed by the compressor 41a of the utilization unit (here, utilization unit 3a), heating can be performed with high-pressure refrigerant in the utilization units (here, utilization units 3b and 3c) that perform heating .

  Therefore, in this case, a condition where heating can be performed without compression of the refrigerant in the specific usage unit as described above is set as the compressor bypass condition, and in the case where the compressor bypass condition is satisfied, The compressor bypass control is performed using the compressor bypass pipes 44a, 44b, and 44c provided in the usage units 3a, 3b, and 3c.

  Specifically, for example, when the outside air temperature is lower than a predetermined outside air temperature, or the pressure difference between the low pressure in the outdoor heat exchanger 21 and the low pressure in the indoor heat exchanger performing cooling is smaller than a predetermined pressure difference In this case, it is determined that the compressor bypass condition is satisfied, and the compressor bypass control as shown in FIG. 8 is performed. That is, the compressor 41a is stopped in the usage unit 3a (the usage unit 3a corresponding to the indoor heat exchanger 52a functioning as the refrigerant evaporator) performing cooling in the same cooling / heating mixed operation (see FIG. 7) as described above. Then, the compressor bypass control is performed to bypass the compressor 41a stopped via the compressor bypass pipe 44a and send it to the discharge side of the compressor 41a stopped from the suction side of the compressor 41a stopping the refrigerant.

  Thereby, here, when the compressor bypass condition is satisfied in the cooling / heating mixed operation mode (heating main), the compressor 41a of the specific use unit (here, the use unit 3a for performing cooling) is appropriately stopped. When the compressor bypass condition is not satisfied, the efficiency with two-stage compression can be achieved by operating all the compressors 41a, 41b, 41c of the utilization units 3a, 3b, 3c that perform heating and cooling. Good driving.

  As the outside air temperature used as the compressor bypass condition, the temperature detected by the outside air temperature sensor 26 can be used. In addition, the pressure difference between the low pressure in the outdoor heat exchanger 21 and the low pressure in the indoor heat exchanger for heating is detected by the suction / discharge pressure sensor of the utilization unit for cooling among the suction / discharge pressure sensors 46a, 46b, 46c. The pressure difference between the refrigerant pressure and the refrigerant pressure detected by the suction / discharge pressure sensor of the utilization unit performing heating can be used.

-Cold balance-
In the cooling / heating mixed operation mode (cooling / heating balance), for example, the usage unit 3b is for cooling, and the usage unit 3c is for heating (that is, the indoor heat exchanger 52b functions as a refrigerant evaporator, and the indoor heat exchanger 52c Functions as a refrigerant radiator), and when the heat load of both utilization units 3b and 3c is balanced and the refrigerant does not flow to the outdoor heat exchanger 21, the refrigerant circuit 20 of the air conditioner 1 is shown in FIG. As shown in FIG. 9 (for the flow of the refrigerant, see the arrow attached to the refrigerant circuit 20 in FIG. 9).

  Specifically, in the use unit 3b (here, the compressor unit 4b), the use side switching mechanism 43b is switched to the cooling cycle state (state shown by the solid line in FIG. 9), and the use unit 3c (here, Then, in the compressor unit 4c), the indoor heat exchange of the utilization unit 3b (here, the indoor unit 5b) is performed by switching the utilization side switching mechanism 43c to the heating cycle state (state shown by the broken line in FIG. 9). Unit 52b functions as a refrigerant evaporator, and the indoor heat exchanger 52c of the usage unit 3c (here, the indoor unit 5c) functions as a refrigerant radiator, and the outdoor heat exchanger 21 of the outdoor unit 2 The refrigerant is not flowing.

  In such a refrigerant circuit 20, the high-pressure gas refrigerant of the refrigeration cycle compressed and discharged by the compressor 41b passes from the utilization unit 3b (here, the compressor unit 4b) through the utilization-side switching mechanism 43b. It is sent to the pipe 72b.

  The high-pressure gas refrigerant sent to the gas refrigerant communication branch pipe 72b passes through the gas refrigerant communication joint pipe 71 and the gas refrigerant communication branch pipe 72c, and the use side switching mechanism 43c of the utilization unit 3c (here, the compressor unit 4c). Sent to

  Then, the high-pressure gas refrigerant sent to the use side switching mechanism 43c is compressed and discharged by the compressor 41c. The gas refrigerant discharged from the compressor 41c is sent to the indoor heat exchanger 52c of the use unit 3c (here, the indoor unit 5c) through the use side switching mechanism 43c and the use side gas refrigerant communication pipe 9c. The high-pressure gas refrigerant sent to the indoor heat exchanger 52c exchanges heat with the indoor air supplied by the indoor fan 53c in the indoor heat exchanger 52c, thereby releasing heat and becoming a high-pressure refrigerant. On the other hand, the room air is heated and supplied indoors to heat the usage unit 3c. The high-pressure refrigerant that has dissipated heat in the indoor heat exchanger 52c is sent to the use-side expansion mechanism 51c. The flow rate of the refrigerant sent to the use side expansion mechanism 51c is adjusted by the use side expansion mechanism 51c, and then the liquid refrigerant in the liquid refrigerant communication pipe 6 from the use unit 3c is transmitted through the use side liquid refrigerant communication pipe 8c and the compressor unit 4c. It is sent to the contact branch pipe 62c.

  Then, the refrigerant sent to the liquid refrigerant communication branch pipe 62c is sent to the use-side expansion mechanism 51b of the usage unit 3b (here, the indoor unit 5b) through the liquid refrigerant communication junction pipe 61 and the liquid refrigerant communication branch pipe 62b. . Specifically, the refrigerant sent to the liquid refrigerant communication branch pipe 62b is sent to the use side expansion mechanism 51b of the indoor unit 5b through the compressor unit 4b and the use side liquid refrigerant communication pipe 8b.

  The refrigerant sent to the use side expansion mechanism 51b is evaporated by performing heat exchange with the indoor air supplied by the indoor fan 53b in the indoor heat exchanger 52b after the flow rate is adjusted in the use side expansion mechanism 51b. It becomes a low pressure gas refrigerant. On the other hand, the room air is cooled and supplied to the room to perform cooling of the usage unit 3b. The low-pressure gas refrigerant evaporated in the indoor heat exchanger 52b is sent to the use-side switching mechanism 43b of the compressor unit 4b through the use-side gas refrigerant communication pipe 9b. The low-pressure gas refrigerant sent to the use side switching mechanism 43b is returned to the suction side of the compressor 41b and compressed again.

  In this way, the operation in the heating / cooling mixed operation mode (heating / cooling balance) is performed. Although the case where the use unit 3b performs cooling and the use unit 3c performs heating has been described here, the present invention is not limited to this, and a use unit performing cooling and a use unit performing heating are If both the cooling load and the heating load of the plurality of usage units 3a, 3b, 3c are balanced, they are included in the cooling / heating mixed operation mode (cooling / heating balance).

  Further, in such a combined cooling and heating operation mode (cooling and heating balance), for example, a target value of the suction pressure (low pressure of the refrigeration cycle) of the compressor 41b is set for the use unit 3b for cooling, and the use unit for heating is performed. A target value of the discharge pressure (high pressure of the refrigeration cycle) of the compressor 41c may be set for 3c, and the operating capacities of the compressors 41b and 41c may be controlled so as to obtain such a target value. Here, as the actual measurement values of the suction pressure and the discharge pressure of the compressors 41b and 41c, the pressure of the refrigerant detected by the suction / discharge pressure sensors 46b and 46c can be used.

  Further, in the above-mentioned combined heating and cooling operation mode (cooling and heating balance), in the usage unit 3c, the refrigerant compressed by the compressor 41b of the usage unit 3b is further compressed by the compressor 41c (that is, the refrigerant compressed by two stages Since heating using) is performed, efficient operation is possible. This is particularly effective under conditions where the cooling load and the heating load are large and the difference between high and low pressure in the refrigeration cycle is large.

  However, conversely, under the condition that the cooling load and the heating load are small and the difference between the high and low pressure of the refrigeration cycle is small, the compressor 41b of the utilization unit (here, utilization unit 3b) performing cooling and the utilization unit (heating here) Even if compression of the refrigerant is not performed by any of the compressors 41c of the utilization unit 3c) or compression of the refrigerant is not performed by the compressors of other utilization units, all utilization units (here, utilization unit 3b) , 3c) can perform cooling and heating.

  Therefore, in this case, a condition where heating can be performed without compression of the refrigerant in the specific usage unit as described above is set as the compressor bypass condition, and in the case where the compressor bypass condition is satisfied, The compressor bypass control is performed using the compressor bypass pipes 44a, 44b, and 44c provided in the usage units 3a, 3b, and 3c.

  Specifically, for example, when the cooling load and the heating load are larger than a predetermined heat load, or when the high and low pressure difference of the refrigeration cycle is smaller than a predetermined high and low pressure difference, it is determined that the compressor bypass condition is satisfied. Then, the compressor bypass control as shown in FIG. 10 is performed. That is, the compressor 41b is stopped in the usage unit 3b (the usage unit 3b corresponding to the indoor heat exchanger 52b functioning as the refrigerant evaporator) performing cooling in the same cooling / heating mixed operation (see FIG. 9) similar to the above. The compressor bypass control is performed to bypass the compressor 41b stopped via the compressor bypass pipe 44b and send it from the suction side of the compressor 41b stopping the refrigerant to the discharge side of the compressor 41b stopped. Alternatively, although not shown here, the compressor 41c is stopped in the utilization unit 3c for heating (the utilization unit 3c corresponding to the indoor heat exchanger 52c functioning as a refrigerant radiator), and the compressor bypass pipe 44c is used. The compressor bypass control is performed to bypass the stopped compressor 41c and send it from the suction side of the stopped compressor 41c to the discharge side of the stopped compressor 41c.

  Thereby, here, when the compressor bypass condition is satisfied in the cooling / heating mixed operation mode (cooling / heating balance), the compressor 41b of the specific utilization unit (in FIG. 10, the utilization unit 3b for performing cooling) is appropriately selected. It is possible to perform the stopped operation, and when the compressor bypass condition is not satisfied, operating all the compressors 41b and 41c of the utilization units 3b and 3c for performing heating and cooling is efficient with two-stage compression. You can drive.

  The difference between the high and low pressure of the refrigeration cycle used as the compressor bypass condition is the pressure and heating of the refrigerant detected by the suction / discharge pressure sensor of the utilization unit for cooling among the suction / discharge pressure sensors 46a, 46b, 46c. The pressure difference with the pressure of the refrigerant detected by the suction / discharge pressure sensor of the utilization unit to be performed can be used.

(3) Features Next, the features of the air conditioner 1 will be described.

<A>
Here, as described above, by connecting the use units 3a, 3b, 3c having the compressors 41a, 41b, 41c and the indoor heat exchangers 52a, 52b, 52c to the outdoor unit 2 having the outdoor heat exchanger 21. In the configured remote condenser type air conditioner 1, by using the use side switching mechanism 43a, 43b, 43c in each use unit 3a, 3b, 3c, cooling and heating in each use unit 3a, 3b, 3c are performed. And can be switched. In addition, the outdoor heat exchanger 21 is shared by the plurality of usage units 3a, 3b, 3c, and the liquid side of the outdoor heat exchanger 21 in the liquid refrigerant communication pipe 6 is on the liquid side of each indoor heat exchanger 52a, 52b, 52c. It branches so as to communicate and connects to each usage unit 3a, 3b, 3c, and branches so that the gas side of the outdoor heat exchanger 21 communicates with each usage side switching mechanism 43a, 43b, 43c in the gas refrigerant communication pipe 7. The outdoor heat exchanger 21 forms a common refrigerant system (refrigerant circuit 20) to the plurality of usage units 3a, 3b, 3c by connecting the usage units 3a, 3b, 3c. For this reason, here, when performing an operation (cooling and heating mixed operation) in which the usage unit performing cooling and the usage unit performing heating coexist, the refrigerant communication pipe between the usage unit performing cooling and the usage unit performing heating Using the outdoor heat exchanger 21 as a refrigerant radiator or evaporator according to the difference between the cooling load in the utilization unit performing cooling and the heating load in the utilization unit performing heating while exchanging the refrigerant through 6 and 7 Can. In addition, since the compressors 41a, 41b, 41c are provided in each of the use units 3a, 3b, 3c, fine operation control can be performed for each of the use units 3a, 3b, 3c. For example, for a usage unit that performs heating, the target value of the discharge pressure (high pressure of the refrigeration cycle) of the compressor is set for each usage unit, and for the usage unit that performs cooling, the suction pressure of the compressor (for each usage unit The target value of the low pressure of the refrigeration cycle can be set, and the operating capacity of the compressors 41a, 41b, 41c can be controlled so as to obtain such a target value.

  Thereby, here, it is comprised by connecting utilization unit 3a, 3b, 3c which has compressor 41a, 41b, 41c and indoor heat exchanger 52a, 52b, 52c to outdoor unit 2 which has outdoor heat exchanger 21. In the remote condenser type air conditioner, cooling / heating mixed operation can be performed while exhaust heat recovery is performed.

<B>
Here, as described above, the indoor units include the utilization units 3a, 3b, 3c, the compressor units 4a, 4b, 4c including the compressors 41a, 41b, 41c, and the indoor heat exchangers 52a, 52b, 52c. The units 5a, 5b, and 5c are configured. Therefore, the indoor units 5a, 5b, 5c can be disposed in the living room and in the vicinity thereof, and the compressor units 4a, 4b, 4c including the compressors 41a, 41b, 41c can be disposed at places away from the living room. Further, as shown in FIG. 11, a plurality (two in this case) of indoor units 5a, 5a, 5b, 5b, 5c, 5c may be connected to the common compressor units 4a, 4b, 4c for each group. it can.

  Thereby, the noise and vibration by compressors 41a, 41b, and 41c can be suppressed in a living room here. Also, the number of compressor units 4a, 4b, 4c can be reduced.

  Further, for example, when the use units 3a, 3b, 3c can be arranged in a place where the problems of noise and vibration due to the compressors 41a, 41b, 41c are small, as shown in FIG. You may employ | adopt the structure of the utilization unit which 4b and 4c and indoor unit 5a, 5b, 5c integrated.

<C>
Here, as described above, the utilization units 3a, 3b, 3c bypass the compressors 41a, 41b, 41c and the refrigerant is taken from the suction side of the compressors 41a, 41b, 41c. It has compressor bypass pipes 44a, 44b and 44c which can be sent to the discharge side of 41c. And since it has such a compressor bypass pipe 44a, 44b, 44c, it is made to compress a refrigerant, or to bypass a refrigerant without compressing a refrigerant for every utilization unit 3a, 3b, 3c. Can be set. For this reason, in this case, it is possible to set, according to need, one that performs compression of the refrigerant and one that does not perform compression of the refrigerant among the use units that perform cooling and heating.

  As a result, in this case, it is possible to perform an operation in which the utilization unit for compressing the refrigerant by the compressor and the utilization unit for bypassing without compressing the refrigerant by the compressor coexist.

  Specifically, here, as described above, the control unit 10 for controlling the devices constituting the outdoor unit 2 and the plurality of usage units 3a, 3b, 3c functions as an indoor heat exchanger, which functions as a refrigerant radiator. As a radiator of refrigerant, it has an operation mode (cooling and heating mixed operation mode) in which the indoor heat exchanger that functions as a refrigerant evaporator is mixed, and the compressor bypass condition is met in this cooling and heating mixed operation mode Stop either the compressor of the utilization unit corresponding to the functional indoor heat exchanger, or the compressor of the utilization unit corresponding to the indoor heat exchanger functioning as the refrigerant evaporator, and stop through the compressor bypass pipe The compressor bypass control is performed such that the refrigerant is bypassed and the refrigerant is stopped from the suction side of the compressor and discharged to the discharge side of the stopped compressor.

  In the cooling / heating mixed operation mode, the refrigerant is exchanged through the refrigerant communication pipes 6 and 7 between the use unit performing cooling and the use unit performing heating, and this is caused by the outside air temperature, the cooling load, and the heating load. Depending on the conditions of high and low pressure of the refrigeration cycle, cooling and heating may be performed in a specific usage unit without compression of the refrigerant in the compressor of the usage unit itself.

  For example, in combined cooling and heating combined operation where the cooling load of the entire plurality of usage units is larger than the heating load and the outdoor heat exchanger functions as a radiator of refrigerant, the outdoor temperature is high, and the outdoor heat exchange is performed. Under the condition that the pressure difference between the high pressure in the heat exchanger and the high pressure in the indoor heat exchanger for heating becomes small, the high pressure sent from the utilization unit for cooling without compression of the refrigerant by the compressor of the utilization unit for heating Heating can be performed with the In addition, in mixed heating / cooling combined operation in which the heating load of the entire plurality of usage units is larger than the cooling load and the outdoor heat exchanger functions as an evaporator of the refrigerant, the outdoor temperature is low, and the outdoor heat exchange is performed. On the condition that the pressure difference between the low pressure in the cooling unit and the low pressure in the indoor heat exchanger for cooling becomes small, the high pressure refrigerant in the utilization unit for heating without compression of the refrigerant by the compressor of the utilization unit for cooling Heating can be performed. Furthermore, in a mixed heating / cooling operation in which cooling load and heating load of the entire plurality of usage units are balanced, cooling is performed under the condition that the cooling load and the heating load are small and the difference between high and low pressure of the refrigeration cycle is small. Even if compression of the refrigerant is performed by either the compressor of the utilization unit or the compressor of the utilization unit performing heating, and compression of the refrigerant is not performed by the compressors of other utilization units, cooling and heating are performed in all utilization units. It can be carried out.

  Therefore, in this case, a condition that can perform cooling and heating without compression of the refrigerant in the specific usage unit as described above is set as the compressor bypass condition, and the compressor bypass in the cooling and heating mixed operation mode is set. When the condition is satisfied, the compressor bypass control provided in each utilization unit is used to perform the compressor bypass control.

  Thus, here, in the combined cooling and heating operation mode, when the compressor bypass condition is satisfied, the operation with the compressor of the specific usage unit can be appropriately stopped, and the compressor bypass condition is not satisfied. In addition, by operating all the compressors of the utilization unit that performs heating and cooling, efficient operation with two-stage compression can be performed.

(4) Modification In the above embodiment (see FIGS. 1, 11 and 12), only one outdoor unit 2 is provided, but as shown in FIG. 13, two outdoor units 2a and 2b are provided. It may have a configuration. Here, since the configuration of the outdoor units 2a and 2b is the same as the configuration of the outdoor unit 2 in the above embodiment, the configurations of the outdoor units 2a and 2b are suffixed with the reference numerals indicating the portions of the outdoor units 2a and 2b. "A" or "b" will be added and the description will be omitted.

  In such a configuration, there is an indoor heat exchanger that functions as a refrigerant radiator as in the all heating operation mode and the cooling / heating mixed operation mode, and the first and second outdoor heat exchangers 21a and 21b are evaporation of the refrigerant. There is an operation mode that functions as a cooling unit, that is, an operation mode in which there is at least one utilization unit that performs heating and the outdoor heat exchanger functions as a refrigerant evaporator. When such an operation mode is continued, the outdoor heat exchangers 21a and 21b frost. For this reason, although it is necessary to perform defrosting by functioning outdoor heat exchangers 21a and 21b temporarily as a radiator of a refrigerant, it is preferred at this time that heating of utilization units 3a, 3b, and 3c can also be continued.

  Therefore, here, first, as shown in FIG. 13, a state in which the first and second outdoor heat exchangers 21a and 21b are made to function as a refrigerant radiator or evaporator, and the first and second outdoor heat exchangers 21a. , 21b can be switched between a state in which one of the first and second outdoor heat exchangers 21a and 21b is made to function as a refrigerant evaporator. It is made to provide further. Then, the first and second outdoor units 2a and 2b are connected to the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7 through the outdoor switching mechanism 2c. Here, the outdoor side switching mechanism 2 c has two outdoor side switching valves 27 and 28 and an on-off valve 29. The first outdoor side switching valve 27 is a four-way connected to the gas side of the first and second outdoor expansion mechanisms 22a, the second outdoor side switching valve 28, and the first and second outdoor heat exchangers 21a and 21b. It is a switching valve. The second outdoor side switching valve 28 includes the liquid refrigerant communication joining pipe 61 of the liquid refrigerant communication pipe 6, the gas refrigerant communication joining pipe 71 of the gas refrigerant communication pipe 7, the first outdoor side switching valve 27, and the second outdoor heat exchange. It is a four-way switching valve connected to the gas side of the vessel 21b. The on-off valve 29 is a valve that opens and closes the flow of the refrigerant between the gas side of the second outdoor heat exchanger 21 b and the first four-way switching valve 27.

  Thus, here, since the first and second outdoor units 2a and 2b are connected to the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7 via the outdoor switching mechanism 2c, every outdoor unit 2a and 3b It is possible to set whether the outdoor heat exchangers 21a and 21b function as a refrigerant radiator or function as a refrigerant evaporator. For this reason, here, among the two outdoor units 2a and 2b, those that cause the outdoor heat exchangers 21a and 21b to function as a refrigerant radiator and those that function as a refrigerant evaporator are set as necessary. can do.

  Thereby, the operation which switches an outdoor unit which makes an outdoor heat exchanger function as a radiator of a refrigerant, and an outdoor unit which makes an outdoor heat exchanger function as an evaporator of a refrigerant can be performed by turns.

  And here, 1st outdoor heat using 1st and 2nd outdoor units 2a and 2b being connected to liquid refrigerant communication pipe 6 and gas refrigerant communication pipe 7 via outdoor side switching mechanism 2c The alternate defrost control is performed to alternately defrost the exchanger 21a and the second outdoor heat exchanger 21b. Specifically, there is an indoor heat exchanger in which the control unit 10 controlling the outdoor unit 2 including the outdoor switching mechanism 2c and the devices constituting the plurality of usage units 3a, 3b, 3c functions as a refrigerant radiator. The first and second outdoor heat exchangers 21a and 21b have an operation mode (all heating operation mode or combined cooling / heating operation mode) in which the first and second outdoor heat exchangers 21a and 21b function as a refrigerant evaporator. Then, in this operation mode, the control unit 10 causes the outdoor switching mechanism 2c to function and the first and second outdoor heat exchangers 21a and 21b to function as a refrigerant radiator or evaporator (see FIG. 14). By switching the first outdoor heat exchanger 21a to function as a refrigerant radiator and switching the second outdoor heat exchanger 21b to function as a refrigerant evaporator (see FIG. 15), the first outdoor heat exchanger 21a is operated. The second outdoor heat exchanger 21b is made to function as a refrigerant radiator and the first outdoor heat exchanger 21a is made to function as a refrigerant evaporator (see FIG. 16). The outdoor heat exchanger 21b is defrosted.

  Therefore, here, the first outdoor heat exchanger and the second outdoor unit are utilized utilizing the fact that the first and second outdoor units are connected to the liquid refrigerant communication pipe and the gas refrigerant communication pipe via the outdoor switching mechanism. The alternate defrost control is performed to alternately defrost the heat exchangers.

  Thus, here, in the operation mode in which at least one utilization unit for heating exists and the outdoor heat exchanger functions as an evaporator of the refrigerant, the heating of the utilization units 3a, 3b and 3c is continued while the two outdoor units are maintained. The heat exchangers 21a and 21b can be defrosted.

  The present invention is widely applicable to a remote condenser type air conditioner configured by connecting a utilization unit having a compressor and an indoor heat exchanger to an outdoor unit having an outdoor heat exchanger.

1 air conditioner 2, 2a, 2b outdoor unit 2c outdoor switching mechanism 3a, 3b, 3c utilization unit 4a, 4b, 4c compressor unit 5a, 5b, 5c indoor unit 6 liquid refrigerant communication tube 7 gas refrigerant communication tube 10 control Sections 21, 21a, 21b Outdoor heat exchangers 41a, 41b, 41c Compressors 43a, 43b, 43c Use side switching mechanisms 44a, 44b, 44c Compressor bypass pipes 52a, 52b, 52c Indoor heat exchangers 61 Liquid refrigerant communication junction pipe 62a, 62b, 62c liquid refrigerant communication branch pipe 71 gas refrigerant communication junction pipe 72a, 72b, 72c gas refrigerant communication branch pipe

Japanese Patent Application Laid-Open No. 58-75676

Claims (6)

A compressor (41a, 41b, 41c), an indoor heat exchanger (52a, 52b, 52c), a state in which the indoor heat exchanger functions as a radiator of refrigerant, and a state in which the indoor heat exchanger functions as an evaporator of the refrigerant A plurality of usage units (3a, 3b, 3c) having switching use side switching mechanisms (43a, 43b, 43c);
An outdoor unit (2, 2a, 2b) not having a compressor and having an outdoor heat exchanger (21, 21a, 21b) common to the plurality of usage units,
A liquid refrigerant communication junction pipe (61) connected to the outdoor unit so as to communicate with the liquid side of the outdoor heat exchanger, and a branch from the liquid refrigerant communication junction pipe to the liquid side of each indoor heat exchanger A liquid refrigerant communication pipe (6) having a plurality of liquid refrigerant communication branch pipes (62a, 62b, 62c) connected to the utilization units so as to communicate with each other;
A gas refrigerant communication junction pipe (71) connected to the outdoor unit to be in communication with the gas side of the outdoor heat exchanger, and a branch from the gas refrigerant communication junction pipe to communicate with the respective use side switching mechanisms A plurality of gas refrigerant communication branch pipes (72a, 72b, 72c) connected to the utilization units, and a gas refrigerant communication pipe (7);
Equipment that configures the outdoor unit and the plurality of usage units so that the indoor heat exchanger that functions as a radiator of the refrigerant and the indoor heat exchanger that functions as an evaporator of the refrigerant coexist Control unit (10) capable of controlling
An air conditioner equipped with (1). Each of the utilization units (3a, 3b, 3c) includes a compressor unit (4a, 4b, 4c) including the compressor (41a, 41b, 41c) and the indoor heat exchanger (52a, 52b, 52c) Containing indoor units (5a, 5b, 5c),
An air conditioner (1) according to claim 1. Each of the utilization units (3a, 3b, 3c) is capable of bypassing the compressor (41a, 41b, 41c) and sending the refrigerant from the suction side of the compressor to the discharge side of the compressor. Machine bypass pipes (44a, 44b, 44c),
An air conditioner (1) according to claim 1 or 2. A compressor (41a, 41b, 41c), an indoor heat exchanger (52a, 52b, 52c), a state in which the indoor heat exchanger functions as a radiator of refrigerant, and a state in which the indoor heat exchanger functions as an evaporator of the refrigerant Use side switching mechanism (43a, 43b, 43c) to be switched, and a compressor bypass pipe (44a, 44a) that can bypass the compressor and send the refrigerant from the suction side of the compressor to the discharge side of the compressor. 44b, 44c), and a plurality of utilization units (3a, 3b, 3c),
An outdoor unit (2, 2a, 2b) having an outdoor heat exchanger (21, 21a, 21b) common to the plurality of usage units;
A liquid refrigerant communication junction pipe (61) connected to the outdoor unit so as to communicate with the liquid side of the outdoor heat exchanger, and a branch from the liquid refrigerant communication junction pipe to the liquid side of each indoor heat exchanger A liquid refrigerant communication pipe (6) having a plurality of liquid refrigerant communication branch pipes (62a, 62b, 62c) connected to the utilization units so as to communicate with each other;
A gas refrigerant communication junction pipe (71) connected to the outdoor unit to be in communication with the gas side of the outdoor heat exchanger, and a branch from the gas refrigerant communication junction pipe to communicate with the respective use side switching mechanisms A plurality of gas refrigerant communication branch pipes (72a, 72b, 72c) connected to the utilization units, and a gas refrigerant communication pipe (7);
A control unit (10) that controls devices that configure the outdoor unit and the plurality of usage units;
Equipped with
The control unit
It has an operation mode in which the indoor heat exchanger functioning as a radiator of the refrigerant and the indoor heat exchanger functioning as an evaporator of the refrigerant coexist.
When the compressor bypass condition is satisfied in the operation mode, the compressor of the utilization unit corresponding to the indoor heat exchanger functioning as a radiator of the refrigerant, and the room functioning as an evaporator of the refrigerant One of the compressors of the utilization unit corresponding to the heat exchanger is stopped, and the stopped compressor is bypassed through the compressor bypass pipe to stop the refrigerant from the suction side of the compressor. Perform compressor bypass control to be sent to the discharge side of the stopped compressor;
Air conditioner (1). The outdoor unit (2, 2a, 2b) includes a first outdoor unit (2a) having a first outdoor heat exchanger (21a) as the outdoor heat exchanger, and a second outdoor heat as the outdoor heat exchanger. And a second outdoor unit (2b) having an exchanger (21b),
A state in which the first and second outdoor heat exchangers function as a radiator or evaporator of the refrigerant, and one of the first and second outdoor heat exchangers function as a radiator of the refrigerant and the first And an outside switching mechanism (2c) capable of switching between the other of the second outdoor heat exchanger and a state in which the other functions as an evaporator of the refrigerant.
The first and second outdoor units are connected to the liquid refrigerant communication pipe (6) and the gas refrigerant communication pipe (7) via the outdoor switching mechanism.
The air conditioning apparatus (1) according to any one of claims 1 to 3. The outdoor unit (2a, 2b) including the outdoor side switching mechanism (2c) and a control unit (10) for controlling devices constituting the plurality of utilization units (3a, 3b, 3c),
The control unit
An operation mode in which the indoor heat exchanger (52a, 52b, 52c) functioning as a radiator of the refrigerant exists, and the first and second outdoor heat exchangers (21a, 21b) function as an evaporator of the refrigerant And have
In the operation mode, the first outdoor heat exchanger is switched from the state where the outdoor switching mechanism (2c) functions as the first and second outdoor heat exchangers as a radiator or evaporator of the refrigerant. The first outdoor heat exchanger is defrosted by functioning as a refrigerant radiator and switching the second outdoor heat exchanger to function as an evaporator of the refrigerant, and then the second outdoor heat exchange Performing alternate defrost control for defrosting the second outdoor heat exchanger by switching the system to a state in which the first outdoor heat exchanger functions as a refrigerant evaporator and the first outdoor heat exchanger functions as a refrigerant evaporator;
An air conditioner (1) according to claim 5.

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